NP DESIGN FOR BRAIN TARGETING
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Transcript of NP DESIGN FOR BRAIN TARGETING
DESIGN OF NANOPARTICLES
FOR BRAIN TARGETING
DISSDipartimento di Scienze della Salute
Francesca Re
Nanomedicine Seminar - Synthesis of nano-biomaterials, modelling, and applications
DRUG DELIVERY and DRUG TARGETING
common issues in the treatment/diagnosis of different diseases
worse for the treatment of diseases affecting the central nervous system (neurodegeneration and cerebral tumors)
There are increasingly high expectations for the delivery of
drugs to the brain using NANOPARTICLES
BLOOD-BRAIN BARRIER
DRUG DELIVERY BY NANOPARTICLES
current challenge:
Considerable efforts have been made to enhance the delivery of therapeutic molecules to the CNS
BUTafter two decades of research, nanotechnology approaches
to brain drug delivery remain yet underdeveloped
state of the art:
to develop drug delivery strategies that will allow the passage of drug molecules from the blood to the brain
in a safe and effective manner
The REASONS for low brain drugs delivery of
targeted nanoparticles:
Biological hurdles Modifications of the NP’s surface that occurs after
administration in biological environment Physical hurdles
SMART DESIGN OF NANOPARTICLES
Biological hurdles: the problem
BLOOD-BRAIN BARRIER
Highly selective barrier
Lack of specific/exclusive molecules on the BBB
Presence of transport mechanisms on the BBB
X2-3 nm
MECHANISMS OF TRANSPORT ACROSS THE BBB Y +
Functionalized nanoparticles
BRAIN
BLOOD
Biological hurdles: potential solutions
[Fernandes C. Pharm Res. 2010]
Lipoproteins
Transwell system for BBB model in vitro
CELLULAR UPTAKE
MONOLAYER PERMEABILITY (cm/min)
Brain capillary endothelial cells
IN VITRO MODELS OF BBB
CHARACTERIZATION OF BBB MODEL
10 11 12 13 14 15 16 17 180
20
40
60
80
100
120
140
Days after seeding (day)
TE
ER
(O
hm
s x
cm2)
TEER = 114.3Ωxcm2
TRANS-ENDOTHELIAL ELECTRICAL RESISTANCE
FUNCTIONAL PROPERTIESBIOELECTRICAL PROPERTIES
SUCROSE PROPRANOLOL
FUNCTIONAL PROPERTIES
RATIO PROPR/SUCR = 1,3
TJ: CLAUDIN AJ: CADERIN
[Re F.; Andreozzi P]
Adsorptive pathways: Cationic proteins: cationic albumin Cell-penetrating peptides: modified TAT-1 from HIV
POTENTIAL LIGANDS FOR THEBBB TARGETING
Receptor-mediated pathways:
A modified receptor-binding domain peptide of ApoE (CWLRKLRKRLLR or its tandem dimer) for LDLR
Anti-TfR antibodies (OX-26, RI-7217)
[Liu X. Biomaterials. 2013]
NP-Cationic albumin
NP-TAT-1 peptide
[Gregori M. J Nanomed Nanotech. 2013]
ADSORPTIVE TRANSCYTOSIS
IN VIVO IN VITRO
NP + modified peptide of the receptor-binding domain of ApoE
IN VITRO
RECEPTOR-MEDIATED TRANSCYTOSIS
[Re F. Nanomedicine. 2011][Bana L. Nanomedicine 2013, submitted]
[Balducci C. PNAS 2013, submitted]
IN VIVO
NP NP + anti-TfR antibody
[Salvati E. Int J Nanomed. 2013][Markoutsa E. Eur J Pharm Biopharm. 2011]
IN VITRO
RECEPTOR-MEDIATED TRANSCYTOSIS
THE NP CHEMICAL DESIGN AFFECTS THE BBB CROSSING:ligand density on the NP surface
LIGAND DENSITY IN THE NP SURFACE
[Re F. J Biotechnol. 2010]
NP-b/s-anti-TfR antibody NP-cov-anti-TfR antibody
THE NP CHEMICAL DESIGN AFFECTS THE BBB CROSSING:method of ligand conjugation on the NP surface
[Salvati E. Int J Nanomed. 2013]
NANOPARTICLES DRUG
NP-MEDIATED DRUG TRANSPORTACROSS THE BBB
[Re F. Nanomedicine. 2011]
The REASONS for low brain delivery of targeted
(drugs) nanoparticles:
Biological hurdles Modifications of the NP’s surface that occurs after
administration in biological environment Physical hurdles
SMART DESIGN OF NANOPARTICLES
The formation of protein corona depend of NP:
SIZE
SURFACE CURVATURE
SURFACE CHEMISTRY
NP
Y Y
YY
Targeting moieties
Protein corona
Y
Y
adsorption of biomolecules to the NP surface
NP with new biological identity
NP-cell membranes interaction
NP cellular uptake and trafficking Biodistribution in vivo
Adsorption of plasma proteins to the NP surface
Modifications of the NP’s surface administration: the problem
[Krol S. J Control Rel. 2012]
SMART SURFACE ENGINEERED APPROACHES
TO AVOID PROTEIN CORONADesign a NP surface that exhibits minimal interaction with biological environment
TO EXPLOIT PROTEIN CORONADesign a NP surface that exhibits a specific interaction with biological environment
NP
Apolipoproteins (ApoE)
Tween 80
Human serum albumin
Modifications of the NP’s surface administration: potential solutions
[Mahon E. J Control Rel. 2012]
Exploiting the protein corona to cross the BBBStriped gold NP
[Verma A. Nat Mater. 2008]
[Verma A. Nat Mater. 2008]
0,0E+00
2,0E-05
4,0E-05
6,0E-05
8,0E-05
1,0E-04
1,2E-04
ST1 ST2 MUS1 MUS2 all-MUS FITC-dex(40 kDa)
sucrose(342 Da)
propranolol(259 Da)
BODIPY
Perm
eabi
lity (
cm/s
ec)
PBS
MEDIUM
CONTROL MOLECULESAu NANOPARTICLES(new)
???(era tutto aggregato)
???(peggio ancora
in medium)
#
#
# **
Ratio prop:sucr~ 1.7
IN VITRO
[unpublished data]
0,0E+00
5,0E-05
1,0E-04
1,5E-04
2,0E-04
2,5E-04
3,0E-04
PBS 2 % FBS 10% FBS
Perm
eabi
lity (
cm/s
ec)
Au NANOPARTICLES(prime preparazioni di striped)
#
*
IN VITRO
[unpublished data]
[unpublished data]
The REASONS for low brain delivery of targeted
(drugs) nanoparticles:
Biological hurdles Modifications of the NP’s surface that occurs after
administration in biological environment Physical hurdles
SMART DESIGN OF NANOPARTICLES
nanoparticles
1° step: NP dilution into the blood
brain
2° step: NP dilution into CSF
An increased retention of the nanoparticles in the brain blood capillaries combined with an adsorption to the capillary walls. This could create a higher concentration gradient that would increase the transport across the endothelial cell layer and as a result enhance the delivery to the brain.
Physical hurdles: the problem
Physical hurdles: potential solutions
[Krol S. J Control Rel. 2012]
[Kreuter J. Adv Drug Del Rev. 2013]
Drugs bound to NP for brain delivery
The development of delivery system to transport drugs into the
brain in a safe and effective manner and in a non-homeopathic
doses are still under exploration
TREATED WITH PBS TREATED WITH LIP
AD MICE MODEL TREATED WITH AMYLOSOMES(functionalized with mApoE as BBB ligand)
Immunohistoch. Cortex + Hippocampus (Ab 6E10)
*
-40%
[Balducci C. PNAS 2013, submitted]
The BBB represents the main mechanism of defense of the CNS
The risk-benefit balance due to NP accumulation in the CNS should be carefully evaluated
NANO-NEUROTOXICITY
Some NP (e.g. gold, TiO2 and silica NP) are able to reach the brain even in the absence of any specific functionalization [Sousa F, 2010 Nanoscale; Wu J, 2011 ACS Nano]