TOXICOLOGY AND CELLULAR INTERACTIONS OF POLYMERIC PARTICULATE DRUG DELIVERY

MATERIALS

Presented by ; Nashwa M Mahmoud Osman,

PhD student; Dual Scheme Supervision between Sohag University, Egypt and Liverpool John Moores University, UK.

Outlines:

Introduction

Aim of the work

Materials and Methods

Future Plans

Introduction:

Targeted drug delivery: “Smart Drug Delivery”

a system which deliver certain drug to a specific tissue or organ or

certain cells.

composed of carriers which have specific physicochemical characters, in

which the drug is loaded.

Drug Loading is relatively high and drugs easily incorporated into the

systems without chemical reaction.

can be used for various routes of administration including oral, nasal,

parenteral, intra-ocular etc.,

Common targets for targeted drug delivery: Cancer, autoimmune

diseases, neurological disorders, pulmonary diseases & cardiovascular

diseases .

What…..Why is it SMART ??? Site –

Specific:

Targeting certain tissues or diseased

cells either through Active or Passive

Targeting.

Controlled Distribution

Receptor mediated

delivery or systems with

specific homing devices

(ligands, Abs).

Taking advantage of tissue

specificity:

Enhanced Permeation and

Retention effect

Monocyte Phagocytic System

pH variations

What…..Why is it SMART ??? Time -

Controlled :

Adjust the onset of drug

release…...Stimuli

Responsive DD.

Maintain circulatory

therapeutic drug level

….increasing the

bioavailability, prolonging the

circulatory half life by

Controlling the release.

Controlled Release

Overall

Advantages:

Safety of drug delivery

Efficacy of the treatment.

Patient compliance.

Harmful drug interactions

Required dose and dose frequency

Side effects

Polymers have been widely used for sustained release of drugs, and adding

functional targeting groups and other moieties has enabled them to be used as

targeted delivery vehicles.

POLYMERS USED IN DRUG DELIVERY

Benefits of Polymer Systems:

Increase stability of volatile drug agents

Produced relatively easily

Vast source of chemistries available

May have engineered specificity both to the drug and the target – difficult to achieve with other carriers

Drug-release profiles and triggering dependent on polymer structure.

Offer closest mimicking of natural products

POLYMERS USED IN DRUG DELIVERY

Types of polymers used:

Biodegradable

Lactides and Glycolidescopolymers

Polyalkyl acrylates

Polyanhydrides.

Non-biodegradable

Acrolein

Epoxy polymers

Synthetic Polymers Proteins

Albumins

Gelatin

Collagen

Carbohydrates

Starch agarose

Carrageenan

Chitosan

Poly(acryl)dextran

Natural Materials

Natural polymers have relatively shorter duration of drug

release but synthetic ones can be designed to fit the drug

and the target tissues and allow sustained release.

Polymeric Composite

With Lipids or

inorganic materials

POLYMERS USED IN DRUG DELIVERY

Types of polymeric Vehicles:An ideal drug delivery vehicle must be non-toxic,

biocompatible, non-immunogenic, biodegradable &

must avoid being recognized by immune system.Dendrimers :

repetitively branched

molecules.Liposomes: a spherical

vesicle composed of a

lipid bilayer.

Micelles: nanostructured

core-shell

Particulates; Nano and Microparticles are

solid colloidal systems described by size

in nanometer and micrometer scale.

Hydrophilic head

Hydrophobic

tail

Aim of the work: Assess the toxicology and cellular interactions of particulate

polymeric drug delivery materials under in vitro conditions.

Comparative study between Nano and Microparticulate

systems of different chemistry (PLGA, PGA co PDL), size

(Different range of sizes in nm and um scale), charge (- ve

and +ve )

Optimization of these materials for use as drug delivery tools.

Materials and Methods:

Polymer synthesis and characterization.

Nanoparticle and Micro particles fabrication

Particle Characterization; Size, Shape & Charge.

In vitro study;

asses cellular interaction and uptake

Toxicological analysis profile

Materials and Methods: Polymer synthesis and characterization:

PGA co PDL :

synthesized by polycondensation ring opening co-polymerization reactions

from Glycerol, Pentadecalactone, Divinyl adipate, 1:1:1 molar ratio, catalyzed by

Novozyme B, a lipase from Candida antarctica immobilized on acrylic resin).

characterized by GPC , 1HNMR and FT-IR spectrum.

Mw of 11.4 Kda

Structure of PGA-co-PDL (1:1:1): 1.34 (s, 22H, H-g), 1.65 (m, 8H, H-e, e0, h),

2.32 (m, 6H, H-d, d0, i), 4.05 (q)-4.18 (m) (6H, H-a, b, c, f), 5.2 (s, H, H-j)

Functional groups : typical broad shallow –OH band appeared at 3447.0 cm1, –

CH2 groups of DVA, PDL, at 2915.7 cm1, –CH group of glycerol appeared at

2848.4 cm1, the carbonyl group of DVA and lactone monomers appeared at

1730.7 cm1, C–O group of lactone, glycerol at 1417.0 and 1164.8 cm1.

PLGA : is to be purchased

Materials and Methods: Particle

Fabrication:

Microparticles :

Prepared by Single emulsion

solvent evaporation technique.

Yield of this method up to

73.33%

Characterized by Zeta sizer to

identify the size range and

charge and by SEM to confirm

the shape.

Nanoparticles:

Suspended Oil Phase/ 300 mg polymer in 8 ml DCM

Aq Phase/ 150 ml of conc. PVA

0.01/ 0.1/ 0.5/ 1/ 3/ 5 % w/v

Microparticles in emulsion

Microparticles

MagneticStirring

Centrifugation, Washing, Freeze Drying

Silverson L5RT mixer, 1000 Stirring / 3hrs

Materials and Methods:SEM images confirm the spherical shape of the MP

Materials and Methods:The average zeta size in nm scale measured using the zeta sizer

Malvern:0.01%PVA0.1%PVA0.5%PVA1%PVA3%PVA5% PVA

4211375846032985353636951

3905589044003920384321411

3645787847134064339318251

1565289822753015121717642

1541336822433116111423042

2193343417913055112730662

3280237723502667243422673

4354225624203014240929633

4099244938522581229926213

3199.222222381231833157.444442374.666672516.22222AV

1134.8478731883.046141183.62452507.3182211062.91286631.855359SD

SDmeanmaxminMP type

631.8553592516.22222369517645% mp

1062.912862374.66667384311143 %mp

507.3182213157.44444406425811%mp

1183.624523183471317910.5% mp

1883.046143812787822560.1 %mp

1134.847873199.22222435415410.01% mp

Materials and Methods:The average zeta surface potential of microparticles measured in mV

by zeta sizer:

0.01%PVA0.1%PVA0.5%PVA1%PVA3%PVA5%PVA

-0.4360.178-0.439-0.1870.409-15.7

0.08290.126-0.294-0.0494-0.168-15.7

-0.1420.392-0.0362-0.0494-0.216-16.4

-17.6-1.89-3.47-10.7-1.450.42

-15.6-1.94-3.47-9.97-1.420.0247

-14.4-1.57-2.97-10.1-1.42-0.366

SDmeanmaxminMP

487.1851263145.26667-16.40.425% mp

489.7055913337.91667-1.450.4093%mp

562.3745323398.07407-10.7-0.04941 %mp

418.6029153505.61111-3.47-0.03620.5% mp

529.0560663199.22222-1.940.3920.1 %mp

8.662263273317.21815-17.60.08290.01 %mp

Materials and Methods: In vitro assessment; the particles show minimal

toxicity

MTT Assay

LDH Assay

0

40

80

120

160

200 % Viability

% Viability

MTT Assay for 3% PVA

MPs

Future plans:

Optimization of The methods of the particle

Fabrications

Positively charging with DOTAP

Complete the toxicological analysis profile, Cellular

uptake & Trans well permeation

Study the biodegradation profile

Love to work as a

team