1-s2.0-S0928493115303222-main (1)

8192019 1-s20-S0928493115303222-main (1)

httpslidepdfcomreaderfull1-s20-s0928493115303222-main-1 111

Electrospinning of PLGAgum tragacanth nano1047297bers containingtetracycline hydrochloride for periodontal regeneration

Marziyeh Ranjbar-Mohammadi a M Zamani bc MP Prabhakaran c S Hajir Bahrami d S Ramakrishna bc

a Textile Engineering Group Department of Engineering University of Bonab Bonab Iranb Mechanical Engineering Department National University of Singapore Singaporec Nanoscience and Nanotechnology Initiative Faculty of Engineering National University of Singapore Singapored Textile Engineering Department Amirkabir University of Technology Tehran Iran

a b s t r a c ta r t i c l e i n f o

Article history

Received 14 May 2015

Received in revised form 23 August 2015

Accepted 27 August 2015

Available online 3 September 2015

Keywords

Gum tragacanth

PLGA

Periodontal regeneration

Electrospun nano1047297bers

Coaxial electrospinning

Controlled drug release is a process in which a predetermined amount of drug is released for longer period

of time ranging from days to months in a controlled manner In this study novel drug delivery devices were

fabricated via blend electrospinning and coaxial electrospinning using poly lactic glycolic acid (PLGA) gum

tragacanth (GT) and tetracycline hydrochloride (TCH) as a hydrophilic model drug in different compositions

and their performance as a drug carrier scaffold was evaluated Scanning electron microscopy (SEM) results

showed that fabricated PLGA blend PLGAGT and core shell PLGAGT nano1047297bers had a smooth and bead-less

morphology with the diameter ranging from 180 to 460 nm Drug release studies showed that both the fraction

of GT within blend nano1047297bers and the corendashshell structure can effectively control TCH release rate from

the nano1047297brous membranes By incorporation of TCH into corendashshell nano1047297bers drug release was sustained

for 75 days with only 19 ofburst release within the1047297rst 2 h The prolonged drug release together with proven

biocompatibility antibacterial and mechanical properties of drug loaded core shell nano1047297bers make them a

promising candidate to be used as drug delivery system for periodontal diseases

copy 2015 Elsevier BV All rights reserved

1 Introduction

Drug delivery systems are engineered technologies for the con-

trolled release of therapeutic agents to achieve therapeutic purposes

in humansor animals In recentyears themarket fordrug delivery tech-

nology (DDT) has increased tremendously [1] and it is forecasted

to reach $136 billion by 2021 [2] Controlled drug release systems

have shown bene1047297ts over conventional drugs [3] such as improved

adequacy reduced side effects improved patient compliance and re-

duced toxicity [45] Electrospinning is one of the developed techniques

which enables the design and production of nanostructured drug car-

riers with high loading capacity encapsulation ef 1047297ciency multi-drug

delivery with ease of operation and cost-effectiveness [67] In most

cases drugs are blended with the polymeric solution to produce drug

incorporated nano1047297bers which might result in low delivery ef 1047297ciency

and burst release [8] while other electrospinning techniques such as

emulsion or coaxial electrospinning showed capabilities to overcome

some of these problems [910] Use of nano1047297brous scaffolds loaded

with antibiotic drugs for biomedical applications especially for treat-

ment of infections after tissue damages such as burn ulcers surgery

or periodontal disease has evoked considerableinterest[11] Mefoxin in-

corporated poly(lactide-co-glycolide) membrane displayed a controlled

release of the drug for over 6 days [12] Kenawyet al [13] fabricated tet-

racycline hydrochloride (TCH) loaded poly(ethylene-co-vinyl acetate)

poly(lactic acid) and their blends then they reported controlled release

of drug over 5 days However controlled release of antibiotics is required

fora longerperiod of time fortreatment of some of thechronicinfections

such as periodontal diseases Nevertheless long term release of hydro-

philic drugs (such as TCH) from nano1047297brous scaffolds is still challenging

due to high solubility of the drug molecule in aqueous mediums It was

previously demonstrated that the compatibility between hygroscopic

properties of drug and polymer is essential to obtain a sustained drug

release from nano1047297brous delivery system [1415]

Poly lactic-co-glycolicacid (PLGA) is a Food and Drug Administration

(FDA) approved synthetic polymer and is one of the most attractive

polymeric candidates used for the fabrication of drug delivery devices

[16] Gum tragacanth (GT) on the other hand is a branched heteroge-

neous and anionic polysaccharide with properties such as moisture ab-

sorption hydrocolloid formation water solubility drug holding and

releasing abilities and it is categorized as generally recognized as safe

Materials Science and Engineering C 58 (2016) 521ndash531

Correspondenceto MP PrabhakaranAmirkabirU niversity of Technology 424Hafez

Ave Tehran Iran

Correspondence to H Bahrami Nanoscience and Nanotechnology Initiative

E3-05-14 Faculty of Engineering 2 Engineering Drive 3 National University of Singapore

Singapore

E-mail addresses nnimppnusedusg (MP Prabhakaran) hajirbautacir

(SH Bahrami)

httpdxdoiorg101016jmsec201508066

0928-4931copy 2015 Elsevier BV All rights reserved

Contents lists available at ScienceDirect

Materials Science and Engineering C

j o u r n a l h o m e p a g e w w w e l s e v i e r c o m l o c a t e m s e c

8192019 1-s20-S0928493115303222-main (1)


(GRAS) material at a level of 020ndash130 in food stuffs This natural bio-

polymer is a mixture of two soluble and insoluble polysaccharides

Tragacanthin a galacturonic acid part of tragacanth which is water

soluble and branched with high molecular weight which gives highly

viscous solutionsand bassorinthe other part of tragacanth is a complex

of methoxylated acids that is insoluble in water and swells to form a gel

or viscous solution [17ndash19] Itis approved asa food additive inEuropean

Unionand has the numberE 413 in the list ofadditivescon1047297rmedby the

Scienti1047297

c Committee for Food of the European Community [20] GTalsoexhibited signi1047297cant potency for wound healing in the form of mucilage

or blended nano1047297bers with PCL or PVA because of an acceleration in

collagenation and proliferation phases of the wound repair [21ndash23]

Thus we hypothesized that incorporation of hydrophilic drugs into

composite nano1047297bers of PLGA and GT could provide a more sustained

and prolonged release of the drug due to better hygroscopic compati-

bility of the drug and polymeric matrix

Here for the1047297rst time we aim towards the fabrication of composite

scaffolds of PLGA and GT at various ratios via blending and coaxial

electrospinning Further we investigated the controlled release of

TCH incorporated within these nano1047297bers along with the physical

characteristics (ie wettability porosity) mechanical properties and

cytocompatibility of the composite nano1047297bers which are critically im-

portant for a nano1047297brousmat to be employed as scaffolds for periodon-

tal disease treatment

2 Experimental procedure

21 Materials

PLGA with lactic acidglycolic acid (LAGA) ratio of 7525 with an

intrinsic viscosity of 072 dl gminus1 was purchased from Boehringer

Ingelheim Pharma GmbH amp Co (Ingelheim Germany) Gum tragacanth

used in this study was a high quality ribbon type collected from the

stems of Fluccosus species of Astragalus bushes grown in the central

areas of Iran TCH (purity N 95) and 111333-hexa1047298uoro-2-propanol

(HFP) was purchased from Sigma Aldrich Human dermal 1047297broblasts

(HDFs) wereobtained from American Type Culture CollectionDulbecco

modi1047297ed Eagles medium (DMEM) fetal bovine serum (FBS) penicillinstreptomycin solution and trypsin-ethylene diamine tetra acetic acid

were purchased from Gibco Invitrogen Corp USA

22 Blend and corendashshell electrospinning

Electrospinning was performed to prepare blend nano1047297bers of

PLGA-GT (PG) in three different weight ratios including 1000 7525

5050 (wt) Polymers were dissolved in HFP for making a total con-

centration of 16 (wv) For fabrication of drug containing nano1047297bers

5 (ww) TCH (based on the total weight of PLGA and GT) was added

and stirred for 30 min Prepared solution was loaded into individual

3-mL syringe attached to a 25G blunted stainless steel needle and a

high voltage of 15 kV was applied to the tip of the needle The 1047298ow

rate of the solutions was maintained at 10 mLh using a syringe pump(KDS 100 KD Scienti1047297c Holliston MA) For fabrication of core shell

nano1047297bers PLGA was dissolved in HFP to obtain 16 (wv) solution

which was used as the shell GT was dissolved in water to obtain 2

(wv) solution and stirred overnight to be used as the core solution

The polymer solutions were separately fed into 3 mL standard syringes

attached to a coaxial nuzzle The inner diameter of shell capillary was

084 mm while the smaller capillary had outer and inner diameters of

056 mm and 030 mm respectively A high voltage of 15 kV (Gamma

High Voltage Research Ormond Beach FL) was applied while the 1047298ow

rate of the shell and core was maintained at 10 mLh and 02 mLh re-

spectively and the polymer solution was drawn into 1047297bers To make

TCH incorporated core shell 1047297bers TCH was added to the core solution

(5 ww) based on the total amount of PLGA and GT considering the

concentration and 1047298aw rate of core and shell solutions Nano1047297bers

were deposited on aluminum wrapped collector at a distance of 15 cm

from the needle tip dried overnight under vacuum and used for charac-

terization drug release and cell proliferation experiments

23 Characterization of nano 1047297bers

The morphology of the electrospun nano1047297bers was studied under a

Field Emission Scanning Electron Microscope (FESEM JEOL JSM-6701-

F Japan) after sputter coating with gold (JEOL JFC-1200 1047297

ne coater Japan) at an accelerating voltage of 15 kV Diameters of the electrospun

1047297bers were analyzed from the SEM images using image analysis soft-

ware (Image J National Institutes of Health USA) Corendashshell structure

of drug loaded PLGA-GT (PG(cs)-TCH) nano1047297bers was examined using

transmission electron microscopy (TEM) (JEOL JFM-3010 Japan) At-

tenuated total re1047298ectance Fourier transform infrared (ATR-FTIR) spec-

troscopic analysis of the electrospun scaffolds was ful1047297lled using a

Nicolet Avatar 380 spectrometer (Thermo Nicolet Waltham MA) over

the range of 600ndash3800 cmminus1 at a resolution of 4 cm

The pore size of the nano1047297brous scaffolds was studied using a CFP-

1200-A capillary 1047298ow porometer (PMI New York NY) Three samples

of each type of nano1047297bers with the same thickness and a dimension of

2 times 2 c m2 were used for measuring the pore size Galwick with a surface

tension of 159 dynescm (PMI New York NY) was used as the wetting

liquid Wettability of the nano1047297bers was determined via contact angle

measurement and a sessile drop method-based video contact angle

system (VCA Optima AST Products Billerica MA) was used for this

purpose The size of the distilled water droplet was set at 10 μ L

The mechanical properties of the electrospun membranes were de-

termined by a uniaxial tensile machine (Instron5943 Canton MA)

with a load cell capacity of 10 N and cross head speed of 5 mm minminus1

All nano1047297ber tape samples were cut in the form of rectangular shape

with dimensions of 30 times 10 mm2 At 1047297rst a white window paper tem-

plate wascut andnano1047297brous tapes were glued onto thetop andbottom

areas of the window It was placed between the grips of the tensile

testing machine and after closing the grips the other sides of the win-

dow papers were cut by a scissor Tensile test was carried out for the

as obtained dry electrospun mats and the 48 h phosphate-buffered sa-

line (PBS) hydrated scaffolds A minimum of six specimens of individualscaffolds were tested

24 Nano 1047297ber degradation studies

To perform the biodegradability test the 1047297bers on cover slips were

immersed in PBS (pH of 74) and incubated for a period of 40 days at

37 degC At eachspeci1047297c time point the scaffolds were washed and subse-

quently driedin a vacuum oven for 48 h The morphology changes were

studied by FESEM

25 TCH release from electrospun nano 1047297bers

Release of TCH from electrospun nano1047297bers was measured using a

UVVIS instrument (Shimadzu 3600 UV ndashVIS-NIR Spectrophotometer)Forthisthe drug containing nano1047297brousmats wereaccuratelyweighed

placed in tightlycapped glass bottle soaked in 1 mL of PBS (pH 74) and

kept in shaking incubator at 37 degC and 150 rpm The UV absorbance of

TCH released in buffer solution was determined at λmax = 362 nm

and converted to the TCH concentration according to the calibration

curve of TCH in the same media [24] The cumulative release of TCH

against release time was further plotted Fig 1 givesthe graphical repre-

sentation of the preparation of nano1047297bers and studying release proper-

ties of them

26 Cell culture and proliferation studies

In vitro biocompatibility of electrospun mats was evaluated

using human dermal 1047297broblast (HDF) cells The proliferation test

522 M Ranjbar-Mohammadi et al Materials Science and Engineering C 58 (2016) 521ndash531

8192019 1-s20-S0928493115303222-main (1)


was done using a colorimetric 3-(45-dimethylthiazol-2-yl)-5-(3-

carboxymethoxyphenyl)-2(4-sulfophenyl)-2H tetrazolium (MTS) assay

(CellTiter 96 AQueous One solution Promega USA) In brief 1047297broblasts

were cultured in DMEM augmented with 10 FBS and 1 antibiotic

and antimycotic solutions in a 75 cm2 cell culture 1047298ask Cells were cul-

tured in a humidi1047297ed incubator at 37 degC with 5 CO2 and the mediawere replaced every two days The nano1047297brous scaffolds were sterilized

under UV radiation for 2 h washed 3 times with PBS and then sank in

DMEM overnight before cell seeding For cell seeding the cells were de-

tached by adding 025 of trypsin containing 01 EDTA centrifuged

counted using a hemocytometer and seeded on the scaffolds placed

in a 24-well plate and tissue culture polystyrene (TCP as control) at a

density of 5000 cells per well After 1 3 and 5 days 1047297broblast seeded

scaffolds were rinsed with PBS and 20 of MTS reagent in serum-free

medium was added After incubation for 3 h aliquots were pipetted

into a 96-well plate and absorbance of the obtained dye was measured

at 492 nm using a spectrophotometric plate reader (FLUO star Optima

BMG Lab Technologies and Germany) The intensity of the obtained

color is directly proportional to the metabolic activity of the cell

population

27 Antibacterial properties

Theantimicrobialbehaviorof PG(cs) PG 7525-TCH and PG(cs)-TCH

nano1047297bers was studied by agar plate method Staphylococcus aureus

ATCC 25923 and Pseudo aeruginosa ATCC 27853 were used as Gram-

positive and Gram-negative bacteria respectively MuellerndashHinton

agar media were sterilized in an autoclave at 121 degC for 20 min under

15 lbsin2 pressures A loop of each bacterium was inoculated on 5 mL

of nutrient broth and incubated at 37 degC for 24 h then cultured in nutri-

ent agar plate The disk shape samples of nano1047297brous mat were steril-

ized by ultraviolet light for 2 h and were placed in a plate Then the

plates were held in an incubator for 24 h Images from the samples

were used for assessing the antimicrobial behavior

28 Statistical analysis

Alldata presentedare expressedas mean plusmn standard deviation(SD)

Statistical analysis was carried out using one-way analysis of variance

(ANOVA) followed by Tukey post hoc test for multiple comparisons

and signi1047297cance was considered at p le 005

3 Results

31 Physical and chemical characterization of nano 1047297bers

The SEM micrographs of the electrospun nano1047297bers are shown in

Fig 2 The optimization of the electrospinning conditions with respect

to the concentration of the polymer applied voltage 1047298ow rate and

distance between the collector and the needle tip was performed thus

producing a continuous stretch of 1047297bers At the optimized condition

uniform bead-free 1047297bers of PLGA blend PG and PG(cs) nano1047297bers

were fabricated by blend and coaxial electrospinning Addition of the

natural polysaccharide (GT) to PLGA produced compositePG nano1047297bers

with diameters much lower than those of PLGA (Table 1) The 1047297ber di-ameter of pure PLGA PG 7525 and PG 5050 without TCH was obtained

as 460 plusmn 16 296 plusmn 25 and 187 plusmn 26 nm respectively which indicates

the reduction in 1047297ber diameter of the composite scaffolds using higher

amounts of gum tragacanth in PG nano1047297bers

At the same time TCH incorporation into PLGA nano1047297bers de-

creased the 1047297ber diameter while TCH loaded PG scaffolds did not ex-

hibit signi1047297cant changes in 1047297ber diameter compared with drug free

scaffolds Fig 2 also exhibited the formation of smooth continuous

and beadless PG(cs) and PG(cs)-TCH nano1047297bers with a diameter of

399 plusmn 31 and 180 plusmn 24 nm respectively Similar to pure PLGA nano-

1047297bers the diameter of TCH loaded core shell nano1047297bers was signi1047297-

cantly lower than that of drug free PG(cs) nano1047297bers Fig 3 shows

the TEM image of drug loaded PG(cs) nano1047297bers prepared by coaxial

electrospinning The TEM micrographof the coaxially electrospun1047297bers

Fig 1 Graphical representation of the preparation of nano1047297bers and studying release properties

523M Ranjbar-Mohammadi et al Materials Science and Engineering C 58 (2016) 521 ndash531

8192019 1-s20-S0928493115303222-main (1)


clearly shows the lsquocorersquo compartment embedded within the shell of the

polymer

The results of pore size measurements are shown in Table 1 The

pore size of the nano1047297brous mats was signi1047297cantly decreased by addi-tion of both GT and drug compared to pure PLGA and similar PG

drug-free scaffolds respectively

The ATR-FTIR spectra of the electrospun PLGA nano1047297bers (Fig 4A)

showed peaks at 1757 cmminus1 1452 cmminus1 1186 cmminus1 and 1089 cmminus1

which correspond to the carbonyl group (CndashO bond) ether group

(CndashOndashC) and methyl group (CndashH) respectively In PG blend nano1047297bersthe peaks of GT have been partially overlapped by the peaks of PLGA

itself and hence the OH peaks appeared weaker for these scaffolds

For drug loaded PLGA nano1047297bers the carbonyl peak appeared broad-

ened because of the hydrogen bonding between the hydroxyl groups

of TCH and C=O groups of PLGA Within the spectra of PLGATCH

scaffolds the stretching frequencies at 1614 and 1579 cmminus1 corre-

spond to the carbonyl groups in A and C rings of TCH respectively

(Fig 4AB) These peaks were seen for the drug loaded PG nano1047297bers

prepared by blend electrospinning but were not obviously visible for

the corendashshell PG-TCH nano1047297bers A mild shift in carbonyl group

wavelength from 1760 to 1754 cmminus1 for drug loaded PG nano1047297bers

in comparison with PG nano1047297bers might have occurred due to the

weakening of some bonds due to hydrogen bonding between drug

and PLGA or GT

Fig 2 Morphology andsize distribution of electrospunnano1047297bersP as PLGA P-TCH as PLGA-TCH PG as PLGAGT PG-TCH as PLGAGT-TCH PG(cs)as coreshell PLGAGT andPG(cs)-TCH

as core shell PLGAGT-TCH)

Table 1

Diameter and pore size of electrospun nano1047297bers

Scaffold Fiber diameter (nm) Average thickness (μ m) Pore size (μ m)

PLGA 460 plusmn 16 6120 292 plusmn 002

PLGA-TCH 288 plusmn 33 6176 095 plusmn 003

PG 7525 296 plusmn 25 6190 180 plusmn 001

PG 7525-TCH 221 plusmn 42 6134 099 plusmn 004

PG 5050 187 plusmn 26 6095 10 plusmn 001

PG 5050 -TCH 180 plusmn 24 6086 063 plusmn 002

PG(cs) 399 plusmn 31 6156 135 plusmn 002

PG(cs)-TCH 197 plusmn 42 6102 12 plusmn 003


8192019 1-s20-S0928493115303222-main (1)


The surface property (interaction with water) of the electrospun

scaffolds was determined dynamically by water contact angle measure-

mentfor a periodof 30s Asshownin Fig 5 with increasing amounts of

GT within the PG composites the hydrophilicity of the nano1047297brous

membrane increased such that PG 7525 and 5050 scaffolds showed

a contact angle value of 85 plusmn 3deg and 76 plusmn 2deg respectively after 30 s

The water contact angle of drug loaded PG nano1047297bers was signi1047297cant-

ly lower than that of drug free PG scaffolds due to the hydrophilic

properties of TCH At the same time the PG(cs) nano1047297bers were more

hydrophilic than the PLGA nano1047297bers However the hydrophilicity of

PG(cs) was lesser compared to PG nano1047297bers due to the presence of

the hydrophilic GT within the core of the nano1047297bers

32 Mechanical properties of as-spun and hydrated scaffolds

The mechanical properties of electrospunnano1047297brousscaffolds with

or without drug including their tensile strength strain at break andelastic modulus were evaluated and are shown in Fig 6 and Table 2

In dry condition the average tensile strength of PLGA nano1047297bers was

obtained as 422 plusmn 002 MPa (Fig 6A) and it exhibited a strain at

break of 11874 plusmn 117 Comparing the stressndashstrain curves of the dif-

ferent scaffolds we found that addition of GT into PLGA nano1047297bers sig-

ni1047297cantly decreased the tensile strength of the nano1047297bers and reduced

the breaking strain (Fig 6B and C) Moreover the results of our studies

showed that PG nano1047297bers had a reduced elastic modulus compared

to pure PLGA nano1047297bers (Table 2) The average tensile strength and

elongation at break of PG(cs) were 332 plusmn 003 MPa and 10283 plusmn

301 respectively which was signi1047297cantly higher than blend nano1047297-

bers (Fig 6D and Table 2) For all formulations incorporation of TCH

into nano1047297bers reduced the tensile strength and elongation at break

while the elastic modulus was increased compared to the scaffolds

without drug

The results of the tensile properties of PBS-hydrated electrospun

scaffolds after 2 days are shown in Fig 7 and Table 2 All the nano1047297bers

without drug showed reduced tensile strength and strain after 2 days

of hydration compared to the dry state except PG 5050 (Fig 7C) with

no signi1047297cant changes Moreover none of the TCH loaded nano1047297bers

Fig 3 TEM micrograph of TCH loaded PG(cs) nano1047297bers

Fig 4 (A)ATR-FTIR spectraof nano1047297bers (P as PLGA P-TCH as PLGA-TCH PG as PLGAGT PG-TCH as PLGAGT-TCH PG(cs)as core shell PLGAGT PG(cs)-TCH as coreshellPLGAGT-TCH)


8192019 1-s20-S0928493115303222-main (1)


8192019 1-s20-S0928493115303222-main (1)


value of elastic modulus (2200plusmn 167 MPa) in wet condition compared

to other formulations (Fig 7D and Table 2)

33 Degradation behavior of nano 1047297bers

Drug diffusion can be affected by scaffolds topology and morpholo-

gy Thusthe topological and morphological changes duringdegradation

might be able to control drug release rate from the nano1047297brous scaf-

folds Fig 8 presents the SEM images of the scaffolds after in vitro deg-

radation for a period of 40 days The 1047297brous structure of PLGA and

PG(cs) scaffolds with and without TCH was partially preserved after

40 days of degradation However blend PG scaffolds with and without

drug swelled to a large extent resulting in loss of nano1047297brous morphol-

ogy within similar time scale These results are in agreement with

higher wettability of PG nano1047297bers compared to PLGA and PG(cs)

nano1047297bers

34 Drug delivery

In this paper we determined the released amounts of TCH by mea-

suringthe absorbance at 362nm using an ultraviolet visible spectropho-

tometer Thereleaseof TCHfrom variouselectrospun scaffoldsis plotted

in Fig 9A amp B PLGA nano1047297bers exhibited an initial burst release of

2320 within the 1047297rst 2 h (Fig 9B) and reached a plateau within

7 days by releasing only 35 of TCH content The burst release of TCH

from PG 7525 nano1047297bers was very similar to pure PLGA (2479)

while PG 5050 had a signi1047297cantly higher amount of TCH (4830) re-

leased in the 1047297rst 2 h followedby a veryfast release of90of drugcon-

tent within 5 days However PG 7525 composite nano1047297bers showed

a sustained TCH release up to a period of 25 days the time point that

it reached to the plateau state For the core shell nano1047297bers where

TCH was incorporated in the core along with GT the burst release was

signi1047297cantly lower (19) compared to both pure PLGA and PG blend

Table 2

Tensile properties of the electrospun nano1047297bers under dry and wet conditions

Samples Dry scaffolds Wet scaffolds

T (μ m) EM (MPa) UTS (MPa) SB () T (μ m) EM (MPa) UTS (MPa) SB ()

PLGA 5680 7600 plusmn 360 422 + 002 11874 plusmn 117 5001 6900 plusmn 180 255 plusmn 003 6409 plusmn 112

PLGA-TCH 5802 8433 plusmn 781 258 plusmn 003 1592 plusmn 212 5277 6236 plusmn 283 171 plusmn 009 1158 plusmn 178

PG 7525 5499 4334 plusmn 223 230 plusmn 002 2240 plusmn 212 5686 4273 plusmn 136 170 plusmn 008 1517 plusmn 113

PG 7525-TCH 5307 6410 plusmn 334 101 plusmn 005 1350 plusmn 691 5430 5211 plusmn 219 102 plusmn 009 1133 plusmn 501



PG(cs) 5204 4020 plusmn 171 332 plusmn 003 10283 plusmn 301 4903 10532 plusmn 121 215 plusmn 002 3667 plusmn 113

PG(cs)-TCH 5375 4832 plusmn 413 151 plusmn 007 1424 plusmn 451 4889 2200 plusmn 167 157 plusmn 003 3341 plusmn 315

T average thickness of nano1047297bers EM elastic modulus UTS ultimate tensile strength SB strain at break

Fig 7 Mechanical properties of PBS hydrated (A) PLGA PLGA-TCH (B) PG 7525 PG 7525-TCH (C) PG 5050 PG 5050-TCH (D) PG(cs) and PG(cs)-TCH electrospun membranes after

48 h (P as PLGA P-TCH as PLGA-TCH PG 7525 as PLGAGT7525PG 7525-TCHas PLGAGT7525-TCHPG 5050 as PLGAGT5050 PG 5050-TCHas PLGAGT5050-TCHPG(cs)as core

shell PLGAGT PG(cs)-TCH as core shell PLGAGT-TCH)


8192019 1-s20-S0928493115303222-main (1)


nano1047297bers Following burst releasePG(cs) scaffolds showed a prolonged

sustained release over the entire study period (75 days) by releasing

6810 of the total TCH content by this time

35 Proliferation of 1047297broblasts on electrospun scaffolds

The cytocompatibility of the electrospun scaffolds was evaluated by

MTS assay after culturing 1047297broblasts on the nano1047297bers over a period of

13 and 5 daysandtheresultsareshownin Fig 10 Cell proliferation on

all the scaffolds (with or without drug) was found to increase with cul-

ture time similar to thetrend observed on tissueculture plates (TCP) At

days 1 and 3 of cell culture GT contained nano1047297bers (both blended and

corendashshell) without drug exhibited improved cell viability compared

to PLGA membranes The same trend was observed for TCH incorpo-

rated nano1047297bers though the presence of TCH slightly decreased cell

growth for some of the formulations compared to drug free nano1047297bers

However after 5 days TCH-loaded PG and PG(cs) nano1047297brous mats did

not exhibit signi1047297cant increase in cell viability compared to PLGA-TCH

Fig 8 SEMimagesof degraded nano1047297bersafter40 days(P as PLGA P-TCH as PLGA-TCHPG 7525 asPLGAGT 7525PG 7525-TCH as PLGAGT7525-TCH PG 5050as PLGAGT5050 PG

5050-TCH as PLGAGT 5050-TCH PG(cs) as core shell PLGAGT PG(cs)-TCH as core shell PLGAGT-TCH)

Fig 9 Release pro1047297le of TCH from PLGA-TCH PG 7525-TCH PG 5050-TCH PG(cs)-TCH electrospun scaffolds A) Entire release time B) initial burst release


8192019 1-s20-S0928493115303222-main (1)


nano1047297bers Moreover none of the electrospun scaffolds showed signif-

icant changes in cell viability after 5 days compared to TCP This is an in-

dication of cytocompatibility of the scaffolds essential for applications

such as treatment of periodontal diseases


In this work the antibacterial activity of TCH-loaded PG(cs) PG

7525-TCH and PG(cs)-TCH nano1047297bers was investigated using S aureus

and Pseudomonas aeruginosa as model bacteriaThe drug loadedsamples

showed clear bacterial inhibition rings against Gram-positive bacteria

(S aureus) which is known to be a TCH-sensitive Gram-positive spheri-

cal bacterium that causes a wide range of suppurative infections The

bacterial inhibition ring was smaller on the nano1047297bers containing

Gram-negative bacteria (P aeruginosa) (Fig 11) These observations

may be related to structural differences between two different bacteria

Gram-negative bacteria are more resistant due to the thick lipopolysac-

charide wall structure

4 Discussion

Periodontitis is a major chronic in1047298ammatory disorder that can lead

to the loss of periodontal support for the periodontal ligament which

leads to the formation of an abnormal gap between the tooth and gum

[25] If the process continues the tooth can eventually get lost For

chronic periodontitis local antimicrobial agents are used as an adjunct

to scaling root planning and restoring the periodontalhealth [25] Mul-

tiple investigations have been conducted to incorporate antibiotics into

the polymeric carriers in order to develop a DDS for treatment of peri-

odontal diseases Polymeric DDS were designed in different structures

Fig 10 Proliferation of 1047297broblasts on electrospun nano1047297bers measured by MTS assay (P as PLGA P-TCH as PLGA-TCH PG 7525 as PLGAGT7525PG 7525-TCHas PLGAGT7525-TCH

PG 5050 as PLGAGT 5050 PG 5050-TCH as PLGAGT 5050-TCH PG(cs) as core shell PLGAGT PG(cs)-TCH as core shell PLGAGT-TCH)

Fig 11 Antibacterial properties of nano1047297bers A) PG(cs) B) PG 7525-TCH and C) PG(cs)-TCH


8192019 1-s20-S0928493115303222-main (1)


such as1047297lms microparticles and1047297bers using bothsynthetic and natural

polymers [26]

TCHis oneof the widely employed antibiotics with proven effective-

nessin acceleration of periodontal treatment [27] TCHwith low toxicity

is a broadspectrum antibiotic which can be applied for thetreatment of

diseases caused by Gram-negative and Gram-positive microorganisms

by inhibiting protein synthesis in the bacteria [28] Besides its antibiotic

property it exhibits anti-in1047298ammatory properties and has the ability

to promote the attachment of 1047297

broblasts TCH has also been reportedas an inhibitor of the activity of proteinases and hence it can be used

to treat or prevent diseases related to proteinase imbalancerheumatoid

arthritis periodontitis and osteomyelitis [29] Previous studies showed

that the long term routine use of TCH for several months resulted

in clinically favorable effects for periodontal disease [30] Controlled

release of TCH was attempted by various researchers using various

drug delivery systems such as supramolecular gels based on amphi-

philic 345-trihydroxybenzoic derivatives[31] device based on ethylene

vinyl acetate (EVA) copolymer [32] and porous calcium phosphate

polyhydroxy butyrate composites [33] for various applications

Recent advances in the1047297eld of nanotechnology enable the fabrication

of nano1047297brous constructs containing drugs such that they have the ar-

chitectural features and morphological similarities matching the native

extracellular matrix (ECM) [3435] Unique properties of nano1047297bers

such as the high surface area high loading ease of operation and cost

effectiveness make them more suitable as drug delivery vehicles How-

ever drug release characteristics (eg burst release release rate and

duration) are signi1047297cantly in1047298uenced by extent of drug encapsulation

into thenano1047297brous scaffolds whichis greatly dependent to material se-

lection as well as the drug incorporation method [3626] In general

drugs can be incorporated into nano1047297bers via various methods such as

coatings blending co-axial and emulsion electrospinning [26] Recent

developments in this direction progressed with the application of nano-

1047297bers as drug delivery systems for periodontal diseases For example

Zamani et al [26] fabricated PCL nano1047297bers containing metronidazole

benzoate where the drug release was continued for a period of 15 days

In this study we explored the incorporation of TCH into a new

bicomponent carrier PLGA-gum tragacanth (GT) via two different

technics of blend electrospinning and coaxial electrospinning GT themedicinally imported polysaccharide consists of two major fractions a

water-soluble (tragacanthic acid and small amount of arabinogalactan)

and an insolublebut water-swellable fraction named bassorinGT exhib-

ited a considerable potency for wound healing in the form of mucilage

[21] or skin regeneration capability in the form of blend nano1047297bers

with PCL or PVA [2223] Due to the mentioned structural and composi-

tional advantages natural availability antibacterial properties and low

cost we believe that TCH loaded PG and PG(cs) 1047297bers can be employed

as a proper drug delivery system for multiple applications including

treatment of periodontal diseases We aimed to explore the effect of in-

corporation method (blending vs coaxial electrospinning) on the phys-

ical characteristics of the nano1047297bers and TCH release behavior from

PG and PG(cs) nano1047297bers Moreover the biocompatibility of the drug

loaded membranes was investigatedThe SEM images (Fig 2) showed that uniformly distributed nano1047297-

bers without beads were formed from all formulations Blending GT

with PLGA decreased the diameter of nano1047297bers Incorporation of TCH

into PLGA and PG(cs) nano1047297bers also reduced the 1047297ber diameter

while addition of the drug into the blend PG nano1047297bers did not cause

further reduction in diameter of the nano1047297bers (Table 1) The possible

reason for the reduction of the diameter of the nano1047297bers is that both

GT and TCH may improve the polarity of the solution which subse-

quently increases the electrical conductivity of the solution Moreover

PG(cs) nano1047297bers exhibited reduced diameter which can be attributed

to theuse of water as the core solvent High dielectric constant of water

(801 at 25 degC) is an indication of the ability of solution to carry more

electrical charges resulting in higher elongation forces and formation

of thinner nano1047297bers under the electrical 1047297eld [37]

The results of mechanical studies showed that PG membranes ex-

hibited less tensile strength compared to PLGA (Figs 6 and 7) This

canbe relatedto theeasier slippage of polymer chainsunder loadingbe-

cause of less entanglements and weak physical interactions among the

chains of mixed polymers [38] Another reason for lower strength of

PG 1047297bers can be the low mechanical strength of GT itself Moreover

TCH could also decrease the tensile strength as well as breaking strain

of all formulations due to probable plasticizing effect of TCH molecules

for polymer chains However the breaking strain of pure PLGA was de-creased more than seven timeswhile blend PG nano1047297bers had less than

50 reduction in strain at the presence of TCH compared to the similar

membranes without drug This can be attributed to the highly branched

structure of GT which intrinsically limited the elongation of its polymer

chains under the loading resulting in alleviation of the in1047298uence of TCH

on reduction of strain at break Mechanical behavior of the nano1047297bers

under wet condition is another factor of consideration since the mem-

branes inserted into the periodontal pocket are exposed to moist condi-

tion Results of mechanical studies under wet conditions showed that

except PG 5050 nano1047297bers other TCH loaded membranes preserved

their tensile strength in wet condition Interestingly the effect of TCH

on breaking strain of PG(cs) was dependent to drywet state of the

membrane In dry state addition of TCH caused a drastic decline in

breaking strain similar to pure PLGA since smaller amount of GT existed

in PG(cs) nano1047297bers compared to blend PG nano1047297bers However there-

duction in breaking strain of PG(cs) was limited to the extent compara-

ble to blend PG nano1047297bers in wetcondition This canbe attributed to the

more pronounced role of GT in hydrated state due to swelling effect of

this natural polymer resultingin distributionand occupationof a higher

volumeof the nano1047297bers by this polymer Forthe membraneswhichare

supposed to be inserted into theperiodontalpocket it is necessaryto in-

sure that the membrane possesses enough mechanical strength and ri-

gidity to be inserted into the pocket and retain its integrity during the

release time On the other hand the membrane should remain 1047298exible

and soft enough in the wet environment to conform to the periodontal

pocket and meet patient compliance [26] Elastic modulus is a good in-

dicator of the stiffness of a material Among various TCH incorporated

composite nano1047297bers PG(cs) exhibited the highest tensile strength

in both dry and wet conditions while its wet modulus was signi1047297-cantly lower than blend nano1047297bers That means TCH loaded PG(cs)

membranes may provide a proper texture to be easily inserted into

periodontal pocket with a certain amount of back pressure and remain

comfortably in the pocket with the lowest rigiditystiffness among the

composite nano1047297bers

The release kinetics of TCH from electrospun PLGA PG 7525

PG 5050 and PG(cs) scaffolds was studied for a period of 75 days

(Fig 9) For all the formulations initial burst release was attributed to

the release of surface connected drug [39] followed by a controlled re-

lease attributed to molecular diffusion through the polymer phase In

case of blended PG nano1047297bers the presence of hydrophilic PG segments

which are randomly distributed across the diffusion path can signi1047297-

cantly facilitate water uptake and swelling of the polymeric matrix

Therefore faster diffusion of the drug molecules out of the nano1047297bersoccurred resulting in higher release rate within the 1047297rst few days and

reaching a plateau after a certain period of time As expected the

explained effect of GT on release rate was enhanced by increasing the

fraction of this polymer in the blend such that the entire amount of

TCH was released from PG 5050 in 20 days These observations are in

agreement with wettability results which con1047297rmed the promoted

wettability of the scaffolds at higher ratios of GT in the nano 1047297bers

(Fig 5) However when GT was employed as the core along with TCH

the likelihood of having drug molecules as well as GT hydrophilic

segments onnear the surface of nano1047297bers is reduced In this case the

hydrophobic PLGA shell could control the water uptake and swelling

of the hydrophilic core material resulting in lowered burst release as

well as prolonged release of TCH in a sustained fashion for 75 days

The prolonged TCH release from PG(cs) nano1047297bers validates the use of


8192019 1-s20-S0928493115303222-main (1)


core shell structure for periodontal treatment since the elimination of

hardened bacteria in periodontal pocket requires sustained exposure

to antibiotics [40]

The cytocompatibility studies showed that GT could successfully

support cell growth on nano1047297brous membranes in both blending and

corendashshell architecture This might be attributed to the more hydro-

philic properties of GT contained membranes which improves protein

adsorption and subsequent cell attachment and proliferation [4142]

On the other hand incorporation of TCH showed to decrease cellgrowth in some of the formulations due to the inhibitory effect of this

drug on mitochondrial protein synthesis [43] However none of the

GT contained scaffolds showed signi1047297cant changes in cell viability com-

pared to the control which demonstrates good cytocompatibility of

the composite membranes Antibacterial assessment of drug loaded

PG and PG(cs) nano1047297bers showed that these scaffolds are strong

enough against of S aureus bacteria

5 Conclusion

In the present study TCH-loaded blend and core shell nano1047297bers

with smooth and bead-less morphology were successfully fabricated

from PLGA and GT for application as new and controlled drug delivery

systems The release rate of TCH in PG blend nano1047297bers increased

with the increase of GT ratio due to enhanced hydrophilicity of the

electrospun nano1047297bers Compared to PG blend nano1047297bers PG(cs) mem-

branes showed a more prolonged release of TCH for 75 days with lower

burst release of the drug within the 1047297rst 2 h Among various formula-

tions PG(cs) nano1047297bers exhibited the highest tensile strength in both

dry and wet conditions while its wet modulus was signi1047297cantly lower

than blend nano1047297bers Thus the TCH loaded PG(cs) membranes might

be strong enough to be easily inserted into periodontal pocket and sus-

tainably release the incorporated drug while affording patient compli-

ance with low rigiditystiffness of the membrane during the treatment

Thesecharacteristics along with the proven cytocompatibility and anti-

bacterial properties of TCH loaded scaffolds suggest the particular ben-

e1047297ts of composite corendashshell nano1047297bers to be used as a drug delivery

system for periodontal diseases

Acknowledgments

This study was supported by the NRF-Technion grant (WBS No

R-398-001-065-592) and the Nanoscience and Nanotechnology Initia-

tive in the National University of Singapore

References

[1] B Felice MP Prabhakaran AP Rodriacuteguez S Ramakrishna J Mater Sci Eng C 4(2014) 178ndash195

[2] P Boisseau B Loubaton C R Phys 12 (2011) 620ndash636

[3] T Allen P Cullis Science 303 (2004) 1818ndash1822[4] Y Malam M Loizidou AM Seifalian Trends Pharmacol Sci 30 (2009) 592ndash599[5] J Zhang R Misra Acta Biomater 3 (2007) 838ndash850[6] B Wang Y Wang T Yin Q Yu Chem Eng Commun 197 (2010) 1315ndash1338[7] ZX Meng XX Xu WZheng HM Zhou LLi YF ZhengX LouJ Colloids SurfB 84

(2011) 97ndash102[8] G Jin MP P rabhakaran D Kai S Ramakrishna Eur J Pharm Biopharm 85 (2013)

689ndash698[9] W QianDGYu YLi YZ LiaoX WangL WangInt JMolSci15 (2014) 774ndash786

[10] H Qi P Hu J Xu A Wang Biomacromolecules 7 (2006) 2327ndash2330[11] TP Chaturvedi R Srivastava AK Srivastava V Gupta VP Kumar Int J Pharm

Investig 2 (2012) 213ndash

217[12] K Kim YK Luu C Chang D Fang BS Hsiao B Chu M Hadjiargyrou J ControlRelease 98 (2004) 47ndash56

[13] R Kenawy GL Bowlin K Mans1047297eld J Layman DG Simpson EH Sanders GEWnek J Control Release 81 (2002) 57ndash64

[14] J Zeng L Yang Q Liang X Zhang H Guan X Xu X Chen X Jing J ControlRelease105 (2005) 43ndash51

[15] X Xu L Yang X Xu X Wang X Chen Q Liang J Zeng X Jing J Control Release108 (2005) 33ndash42

[16] HK Makadia S Siegel Polymers (Basel) 3 (2011) 1377ndash1397[17] MU Adikwu Bentham Science Publishers (2009)[18] A Rasul M Iqbal G Murtaza MK Waqas M Hanif Acta Pol Pharm 67 (2010)

517ndash522[19] B Singh V Sharma Carbohydr Polym 101 (2014) 928ndash940[20] DMW Anderson MME Bridgeman Phytochemistry 24 (1985) 2301ndash2304[21] A Moghbel AAHemmatiH Agheli I RashidiK Amraee Arch Iran Med8 (2005)

257ndash262[22] M Ranjbar-MohammadiSH BahramiMT Joghataei J Mater SciEng C 33 (2013)

4935ndash4943

[23] M Ranjbar-Mohammadi SH Bahrami J Mater Sci Eng C 48 (2015) 71ndash79[24] CL He ZM Huang XJ Han J Biomed Mater Res A 89 (2009) 80ndash95[25] S PappalardoOA Baglio C Cappello S Guarrera M De Benedittis M Petruzzi RF

Grassi Minerva Stomatol 55 (2006) 655ndash661[26] M Zamani M Morshed J Varshosaz M Jannesari Eur J Pharm Biopharm 75

(2010) 179ndash185[27] G Isik S Ince F Saglam U Onan J Clin Periodontol 24 (1997) 589ndash594[28] AN Sapadin R Fleischmajer J Am Acad Dermatol 54 (2006) 258ndash265[29] ZR Domingues ME Cortes TA Gomes HF Diniz CS Freitas JB Gomes AMC

Faria RD Sinisterra Biomaterials 25 (2004) 327ndash333[30] RA Seymour PA Heasman J Clin Periodontol 22 (1995) 22ndash35[31] L Chen J Wu L Yuwen T Shu M Xu M Zhang T Yi Langmuir 25 (2009)

8434ndash8438[32] S Kalachandra L Dongming S Offenbacher J Mater Sci Mater Med 13 (2002)

53ndash58[33] LMedvecky R StulajterovaJ BriancinChemPap 61 (2007) 477ndash484 (composites)[34] E Vatankhah MP Prabhakaran G Jin L GhasemiMobarakeh S Ramakrishna

J Biomater Appl 28 (2013) 909ndash921[35] MC Bottino V Thomas G Schmidt YK Vohra TMG Chua MJ Kowolik GM

Janowski Dent Mater 2 (2012) 703ndash721[36] M Zamani MP Prabhakaran S Ramakrishna Int J Nanomedicine 8 (2013)

2997ndash3017[37] WK Son JH Youk TS Lee WH Park Polymer 45 (2004) 2959ndash2966[38] Y Zhang H Ouyang CT Lim S Ramakrishna ZM Huang J Biomed Mater Res B

Appl Biomater 72B (2005) 156ndash165[39] DH LewisIn M Chasin RLanger (eds) NewYork MarcelDekker Inc (1990)1ndash43[40] WJ Loesche NS Grossman Clin Microbiol Rev 14 (2001) 727ndash752[41] S Fleischer A Shapira O Regev N Nseir E Zussman T Dvir Biotechnol Bioeng

111 (2014) 1246ndash1257[42] R Ravichandran R Sridhar JR Venugopal S Sundarrajan S Mukherjee S

Ramakrishna Macromol Biosci 14 (2014) 515ndash525[43] C van den Bogert G van Kernebeek L Leij AM Kroon Cancer Lett 32 (1986)

341ndash351


8192019 1-s20-S0928493115303222-main (1)


(GRAS) material at a level of 020ndash130 in food stuffs This natural bio-

polymer is a mixture of two soluble and insoluble polysaccharides

Tragacanthin a galacturonic acid part of tragacanth which is water

soluble and branched with high molecular weight which gives highly

viscous solutionsand bassorinthe other part of tragacanth is a complex

of methoxylated acids that is insoluble in water and swells to form a gel

or viscous solution [17ndash19] Itis approved asa food additive inEuropean

Unionand has the numberE 413 in the list ofadditivescon1047297rmedby the

Scienti1047297

c Committee for Food of the European Community [20] GTalsoexhibited signi1047297cant potency for wound healing in the form of mucilage

or blended nano1047297bers with PCL or PVA because of an acceleration in

collagenation and proliferation phases of the wound repair [21ndash23]

Thus we hypothesized that incorporation of hydrophilic drugs into

composite nano1047297bers of PLGA and GT could provide a more sustained

and prolonged release of the drug due to better hygroscopic compati-

bility of the drug and polymeric matrix

Here for the1047297rst time we aim towards the fabrication of composite

scaffolds of PLGA and GT at various ratios via blending and coaxial

electrospinning Further we investigated the controlled release of

TCH incorporated within these nano1047297bers along with the physical

characteristics (ie wettability porosity) mechanical properties and

cytocompatibility of the composite nano1047297bers which are critically im-

portant for a nano1047297brousmat to be employed as scaffolds for periodon-

tal disease treatment

2 Experimental procedure

21 Materials

PLGA with lactic acidglycolic acid (LAGA) ratio of 7525 with an

intrinsic viscosity of 072 dl gminus1 was purchased from Boehringer

Ingelheim Pharma GmbH amp Co (Ingelheim Germany) Gum tragacanth

used in this study was a high quality ribbon type collected from the

stems of Fluccosus species of Astragalus bushes grown in the central

areas of Iran TCH (purity N 95) and 111333-hexa1047298uoro-2-propanol

(HFP) was purchased from Sigma Aldrich Human dermal 1047297broblasts

(HDFs) wereobtained from American Type Culture CollectionDulbecco

modi1047297ed Eagles medium (DMEM) fetal bovine serum (FBS) penicillinstreptomycin solution and trypsin-ethylene diamine tetra acetic acid

were purchased from Gibco Invitrogen Corp USA

22 Blend and corendashshell electrospinning

Electrospinning was performed to prepare blend nano1047297bers of

PLGA-GT (PG) in three different weight ratios including 1000 7525

5050 (wt) Polymers were dissolved in HFP for making a total con-

centration of 16 (wv) For fabrication of drug containing nano1047297bers

5 (ww) TCH (based on the total weight of PLGA and GT) was added

and stirred for 30 min Prepared solution was loaded into individual

3-mL syringe attached to a 25G blunted stainless steel needle and a

high voltage of 15 kV was applied to the tip of the needle The 1047298ow

rate of the solutions was maintained at 10 mLh using a syringe pump(KDS 100 KD Scienti1047297c Holliston MA) For fabrication of core shell

nano1047297bers PLGA was dissolved in HFP to obtain 16 (wv) solution

which was used as the shell GT was dissolved in water to obtain 2

(wv) solution and stirred overnight to be used as the core solution

The polymer solutions were separately fed into 3 mL standard syringes

attached to a coaxial nuzzle The inner diameter of shell capillary was

084 mm while the smaller capillary had outer and inner diameters of

056 mm and 030 mm respectively A high voltage of 15 kV (Gamma

High Voltage Research Ormond Beach FL) was applied while the 1047298ow

rate of the shell and core was maintained at 10 mLh and 02 mLh re-

spectively and the polymer solution was drawn into 1047297bers To make

TCH incorporated core shell 1047297bers TCH was added to the core solution

(5 ww) based on the total amount of PLGA and GT considering the

concentration and 1047298aw rate of core and shell solutions Nano1047297bers

were deposited on aluminum wrapped collector at a distance of 15 cm

from the needle tip dried overnight under vacuum and used for charac-

terization drug release and cell proliferation experiments

23 Characterization of nano 1047297bers

The morphology of the electrospun nano1047297bers was studied under a

Field Emission Scanning Electron Microscope (FESEM JEOL JSM-6701-

F Japan) after sputter coating with gold (JEOL JFC-1200 1047297

ne coater Japan) at an accelerating voltage of 15 kV Diameters of the electrospun

1047297bers were analyzed from the SEM images using image analysis soft-

ware (Image J National Institutes of Health USA) Corendashshell structure

of drug loaded PLGA-GT (PG(cs)-TCH) nano1047297bers was examined using

transmission electron microscopy (TEM) (JEOL JFM-3010 Japan) At-

tenuated total re1047298ectance Fourier transform infrared (ATR-FTIR) spec-

troscopic analysis of the electrospun scaffolds was ful1047297lled using a

Nicolet Avatar 380 spectrometer (Thermo Nicolet Waltham MA) over

the range of 600ndash3800 cmminus1 at a resolution of 4 cm

The pore size of the nano1047297brous scaffolds was studied using a CFP-

1200-A capillary 1047298ow porometer (PMI New York NY) Three samples

of each type of nano1047297bers with the same thickness and a dimension of

2 times 2 c m2 were used for measuring the pore size Galwick with a surface

tension of 159 dynescm (PMI New York NY) was used as the wetting

liquid Wettability of the nano1047297bers was determined via contact angle

measurement and a sessile drop method-based video contact angle

system (VCA Optima AST Products Billerica MA) was used for this

purpose The size of the distilled water droplet was set at 10 μ L

The mechanical properties of the electrospun membranes were de-

termined by a uniaxial tensile machine (Instron5943 Canton MA)

with a load cell capacity of 10 N and cross head speed of 5 mm minminus1

All nano1047297ber tape samples were cut in the form of rectangular shape

with dimensions of 30 times 10 mm2 At 1047297rst a white window paper tem-

plate wascut andnano1047297brous tapes were glued onto thetop andbottom

areas of the window It was placed between the grips of the tensile

testing machine and after closing the grips the other sides of the win-

dow papers were cut by a scissor Tensile test was carried out for the

as obtained dry electrospun mats and the 48 h phosphate-buffered sa-

line (PBS) hydrated scaffolds A minimum of six specimens of individualscaffolds were tested

24 Nano 1047297ber degradation studies

To perform the biodegradability test the 1047297bers on cover slips were

immersed in PBS (pH of 74) and incubated for a period of 40 days at

37 degC At eachspeci1047297c time point the scaffolds were washed and subse-

quently driedin a vacuum oven for 48 h The morphology changes were

studied by FESEM

25 TCH release from electrospun nano 1047297bers

Release of TCH from electrospun nano1047297bers was measured using a

UVVIS instrument (Shimadzu 3600 UV ndashVIS-NIR Spectrophotometer)Forthisthe drug containing nano1047297brousmats wereaccuratelyweighed

placed in tightlycapped glass bottle soaked in 1 mL of PBS (pH 74) and

kept in shaking incubator at 37 degC and 150 rpm The UV absorbance of

TCH released in buffer solution was determined at λmax = 362 nm

and converted to the TCH concentration according to the calibration

curve of TCH in the same media [24] The cumulative release of TCH

against release time was further plotted Fig 1 givesthe graphical repre-

sentation of the preparation of nano1047297bers and studying release proper-

ties of them

26 Cell culture and proliferation studies

In vitro biocompatibility of electrospun mats was evaluated

using human dermal 1047297broblast (HDF) cells The proliferation test


8192019 1-s20-S0928493115303222-main (1)




















population


















3 Results


























8192019 1-s20-S0928493115303222-main (1)



polymer




















and PLGA or GT



Table 1





PG 7525 296 plusmn 25 6190 180 plusmn 001


PG 5050 187 plusmn 26 6095 10 plusmn 001





8192019 1-s20-S0928493115303222-main (1)






























without drug









8192019 1-s20-S0928493115303222-main (1)


8192019 1-s20-S0928493115303222-main (1)















nano1047297bers

34 Drug delivery















Table 2

















8192019 1-s20-S0928493115303222-main (1)






















8192019 1-s20-S0928493115303222-main (1)


















4 Discussion














8192019 1-s20-S0928493115303222-main (1)



polymers [26]































































































































8192019 1-s20-S0928493115303222-main (1)




to antibiotics [40]













5 Conclusion



















Acknowledgments




References















4935ndash4943













341ndash351


8192019 1-s20-S0928493115303222-main (1)




















population


















3 Results


























8192019 1-s20-S0928493115303222-main (1)



polymer




















and PLGA or GT



Table 1





PG 7525 296 plusmn 25 6190 180 plusmn 001


PG 5050 187 plusmn 26 6095 10 plusmn 001





8192019 1-s20-S0928493115303222-main (1)






























without drug









8192019 1-s20-S0928493115303222-main (1)


8192019 1-s20-S0928493115303222-main (1)















nano1047297bers

34 Drug delivery















Table 2

















8192019 1-s20-S0928493115303222-main (1)






















8192019 1-s20-S0928493115303222-main (1)


















4 Discussion














8192019 1-s20-S0928493115303222-main (1)



polymers [26]































































































































8192019 1-s20-S0928493115303222-main (1)




to antibiotics [40]













5 Conclusion



















Acknowledgments




References















4935ndash4943













341ndash351


8192019 1-s20-S0928493115303222-main (1)



polymer




















and PLGA or GT



Table 1





PG 7525 296 plusmn 25 6190 180 plusmn 001


PG 5050 187 plusmn 26 6095 10 plusmn 001





8192019 1-s20-S0928493115303222-main (1)






























without drug









8192019 1-s20-S0928493115303222-main (1)


8192019 1-s20-S0928493115303222-main (1)















nano1047297bers

34 Drug delivery















Table 2

















8192019 1-s20-S0928493115303222-main (1)






















8192019 1-s20-S0928493115303222-main (1)


















4 Discussion














8192019 1-s20-S0928493115303222-main (1)



polymers [26]































































































































8192019 1-s20-S0928493115303222-main (1)




to antibiotics [40]













5 Conclusion



















Acknowledgments




References















4935ndash4943













341ndash351


8192019 1-s20-S0928493115303222-main (1)






























without drug









8192019 1-s20-S0928493115303222-main (1)


8192019 1-s20-S0928493115303222-main (1)















nano1047297bers

34 Drug delivery















Table 2

















8192019 1-s20-S0928493115303222-main (1)






















8192019 1-s20-S0928493115303222-main (1)


















4 Discussion














8192019 1-s20-S0928493115303222-main (1)



polymers [26]































































































































8192019 1-s20-S0928493115303222-main (1)




to antibiotics [40]













5 Conclusion



















Acknowledgments




References















4935ndash4943













341ndash351


8192019 1-s20-S0928493115303222-main (1)


8192019 1-s20-S0928493115303222-main (1)















nano1047297bers

34 Drug delivery















Table 2

















8192019 1-s20-S0928493115303222-main (1)






















8192019 1-s20-S0928493115303222-main (1)


















4 Discussion














8192019 1-s20-S0928493115303222-main (1)



polymers [26]































































































































8192019 1-s20-S0928493115303222-main (1)




to antibiotics [40]













5 Conclusion



















Acknowledgments




References















4935ndash4943













341ndash351


8192019 1-s20-S0928493115303222-main (1)















nano1047297bers

34 Drug delivery















Table 2

















8192019 1-s20-S0928493115303222-main (1)






















8192019 1-s20-S0928493115303222-main (1)


















4 Discussion














8192019 1-s20-S0928493115303222-main (1)



polymers [26]































































































































8192019 1-s20-S0928493115303222-main (1)




to antibiotics [40]













5 Conclusion



















Acknowledgments




References















4935ndash4943













341ndash351


8192019 1-s20-S0928493115303222-main (1)






















8192019 1-s20-S0928493115303222-main (1)


















4 Discussion














8192019 1-s20-S0928493115303222-main (1)



polymers [26]































































































































8192019 1-s20-S0928493115303222-main (1)




to antibiotics [40]













5 Conclusion



















Acknowledgments




References















4935ndash4943













341ndash351


8192019 1-s20-S0928493115303222-main (1)


















4 Discussion














8192019 1-s20-S0928493115303222-main (1)



polymers [26]































































































































8192019 1-s20-S0928493115303222-main (1)




to antibiotics [40]













5 Conclusion



















Acknowledgments




References















4935ndash4943













341ndash351


8192019 1-s20-S0928493115303222-main (1)



polymers [26]































































































































8192019 1-s20-S0928493115303222-main (1)




to antibiotics [40]













5 Conclusion



















Acknowledgments




References















4935ndash4943













341ndash351


8192019 1-s20-S0928493115303222-main (1)




to antibiotics [40]













5 Conclusion



















Acknowledgments




References















4935ndash4943













341ndash351


1-s2.0-S0928493115303222-main (1)

Documents

Transcript of 1-s2.0-S0928493115303222-main (1)