Biodegradable nanoparticles for drug and gene delivery to cells and tissues

Presented by

Naila Sajjad10-arid-1766PhD Biochemistry Biodegradable nanoparticles for drug and gene delivery to cells and tissuesContentSignificance of nanotechnology for drug therapyNanoparticlesSignificance of particle sizeBiodegradable polymers PLGA &PLAIntracellular traffickingTherapeutic applications of PLGA nanoparticles

ContiSustained gene deliveryProtein deliveryVaccine adjuvantIntracellular targetingTissue targetingconclusionFuture prospectsReferences Nanotechnology Nanoscience

Research at the scale of 100nm or less

Nanomedicice

Drug delivery systemSignificance of nanotechnology for drug therapySuitable means of delivering small mol wt drugs & macromolecules such as protein peptides or genes (Moghimi et al.,2001)

Targeted (cellular/tisue) delivery of drug (Vinagradov et al., 2002)Significance of particle sizeHigh intracellular uptake (Desai et al., 1997)

Efficiently penetrate throughout submucosal layers

Cross the blood-brain barrier

Biodegradable polymers PLGA &PLASynthetic polymer

Polylactide (PLA) and poly (D,L-Lactide-co-glycolide)(PLGA)

Hydrolysis

Polymer biodegradationConti..

Plasmid DNA loaded nanoparticle

Formation of PLGA nanoparticlesEmulsion solvent evaporation technique (Jain,2000)

Polyvinyl alcohol (PVA) (Sahoo., 2002)

Commonly used emulsifierUniform and smaller in sizehydrophilicSolvent evaporation technique

Intracellular traffickingDelivery of therapeutic agents to specific compartments or organelles within the cell

Targeted delivery is the higher bioavailability of therapeutic agent at its site of actionRelease of drug entrapped in PLGA matrixDiffusion

Block coplymer composition and mol wt.

Release of encapsulated therapeutic agent (Lin et al., 2000)Uptake of nanoparticles in S.M.C and V.E.CPhagocytosis

Fluid phase pinocytosis

Receptor-mediated endocytosisIntracellular uptake pathway

ContiIntracellular trafficking of nanoparticles

Transmission electron microscopic picture of PLGA nanoparticles in the cytoplasm of vascular smooth muscle

Conti Uptake of nanoparticles is time dependent

Surface charge reversalMechanism responsible for the endolysosomal escape of nanoparticleNanoparticles interact with vesicular membrane inside the cell (Panyam et al., 2002)

Destabilization of membrane

Escape of nanoparticles into cytoplasmic compartmentExocytosis of nanoparticlesProtein (albumin)in serum

Antiproliferative effect of dexamethasone-loaded nanoparticles in smooth muscle cell (Davda et al., 2002)Therapeutic applications of PLGA nanoparticlesSustained gene delivery

Protein delivery

Intracellular targeting

Tissue targetingSustained gene deliveryNanoparticles containing encapsulated plasmid DNA

Lysosomal enzymes

Hedley at al demonstrated protection of DNA from nuclease when encapsulated into PLGA microsphere

Rat bone osteotomy model (Labhasetwar et al., 1999)Marker gene (Fire fly luciferase &heat sensitive human placental alakaline phosphatase)Gene expression in cell culture in the presence of serum

Use of PLGA emulsion containing alkaline phosphatase as marker gene for coating gut suture

Rat skeletal muscles (Cohen et al., 2000)Protein deliveryEncapsulation of therapeutic proteins & peptide into nanoparticles using emulsion solvent technique (Davda et al., 2000)

Loss of therapeutic efficiency due to denaturation/degradation of proteinReasons of protein inactivationExposure to organic solvents leading to protein adsorption at oil-water interface (Lu et al., 2000)

Acidic environment generated during degradation of PLGA matrix due to formation of acidic monomers and oligomers (Zhu et al., 2000)Protection of proteinAddition of Bovine serum albumin to aqueous phase before emulsification (Weert et al., 2000)

By including buffering base such as magnesium hydroxide to PLGA microsphere formation (Zhu et al., 2000)Vaccine adjuvantNano and microparticles containing antigen (Raghuvanshi et al., 2001)

Alternative to currently used alum

Provide sustained release of antigenSystemic and mucosal immunityAdjuvant properties of PLGA nanoparticles containing

encapsulated staphylococcal enterotoxin B toxoidImmune response through nanoparticles injection following injection of alumMaximum at 7 weeks then gradually decreased with time

Secondary immune response at 19th week

Synergistic immune response after co-injection of TT alum along with TT-loaded nanoparticles (Raghuvanshi et al., 2001)Intracellular targetingSurface charge of nanoparticles (Panyam et al., 2002)

Surface modification of nanoparticles with cationic agents like didodecyldimethylammonium bromide (DMAB)

Variation in physical properties

Attachment of nuclear localization signal to nanoparticle surfaceTissue targetingMonoclonal antibodies

Epoxy-activation method

Active and passive targetingFuture prospectsSustained dilivery

Issues in drug delivery are becoming more important and specific drugs become available with the knowledge about diseases available from the human genome project

All therapeutic agents would optimally require drug delivery and targeting mechanisms to deliver them to target tissues without reducing their therapeutic efficacy.

ContiAs the pathophysiology of disease conditions and their cellular mechanisms are understood, drug delivery systems customized to achieve optimal therapeutic efficacy will be more effectiveNanoparticles, because of their versatility for formulation, sustained release properties, sub-cellular size and biocompatibility with tissue and cells appear to be a promising system to achieve these important objectivesConclusion Use of biodegradable nanoparticles formed from poly (D,L-Lactide-co-glycolide)(PLGA) for target delivery of plasmid DNA, proteins and low molecular wt compound

Rapid escape of PLGA nanoparticles from the endo-lysosomal compartment into cytosolReferencesMaghimi, S.M., A.C.Hunter and J.C. Murray. 2001. Long circulating and target specific nanoparticle.theory to practice. Pharmacol. Rev. 283-318.Vinagradov, S.V., T.K. Bronich and A.V.Kabanov. 2002. Nanosized cationic hydrogels for drug delivery preparation, properties and interaction with cells. Adv. Drug. Del. Rev. 223-233.Labhasetwar, V., J.Bonadio, S.A.Goldstein and R.J.Levy.1999.Gene transfection using biodegradable nanosphere: results in tissue culture and rat osteotomy model. Colloids surfaces. B. Biointerfaces. 281-290.Desai,M.P., V.Labhasetwar, E.Walter, R.J.Levy and G.L. Amidon.1997. The mechanism of uptake of biodegradable microparticle in caco-2cells in size dependent. Pharm.Res. 1568-1573.Sahoo, S.K., J.Panyam, S.Prabhe and V. Labhasetwar. 2002. Residual polyvinyl alcohol associated with poly(D,L-Lactide-co-glycolide)nanoparticles affects their physical properties and cellular uptake. J.Control.Release. 105-114.

Conti Weert, M.V.D., J. Hoechstetter, W.E. Hennink, D.J. Crommelin. 2000.The effect of a water/organic solvent interface on the structural stability of lysozyme. J. Control. 351359 Lu,L., G.N. Stamatas, A.G. Mikos. 2000. Controlled release of transforming growth factor beta1 from biodegradable polymer microparticles. J. Biomed. Mater. Res.440451 Raghuvanshi,R.J., A. Mistra, G.P. Talwar, R.J. Levy, V. Labhasetwar. 2001.Enhanced immune response with a combination of alum and biodegradable nanoparticles containing tetanus toxoid. J. Microencapsul. 723732

Conti..Cohen,H., R.J. Levy, J. Gao, I. Fishbein, V. Kousaev, S. Sosnoski, S. Slomkowski. 2000. Sustained delivery and expression of DNA encapsulated in polymeric nanoparticles. Gene Ther.18961905 Davda,J., V. Labhasetwar. 2002.Characterization of nanoparticle uptake by endothelial cells.Int. J. Pharm.(2002), pp. 5159

Panyam,J., W.Z. Zhou, S. Prabha, S.K. Sahoo, V. Labhasetwar. 2002.Rapid endo-lysosomal escape of poly (d,l-lactide-co-glycolide) nanoparticles: Implications for drug and gene delivery. FASEB J.12171226Panyam, J., V. Labhesetwar. 2012. Biodegradable nanoparticles for drug and gene delivery to cells and tissues. J. Pharm. Sci. 64: 61-71

Conti.. Lin,S.Y., K.S. Chen, H.H. Teng, M.J. Li.2000In vitro degradation and dissolution behaviours of microspheres prepared by three low molecular weight polyesters.J. Microencapsul., 577586