title: Molecular mechanism of poly(vinyl alcohol) mediated prevention of aggregation and stabilization of insulin in nanoparticles.
abstract: It is a challenge to formulate polymer based nanoparticles of therapeutic proteins as excipients and process conditions affect stability and structural integrity of the protein. Hence, understanding the protein stability and complex aggregation phenomena is an important area of research in therapeutic protein delivery. Herein we investigated the comparative role of three kinds of surfactant systems (Tween 20:Tween 80), small molecular weight poly(vinyl alcohol) (SMW-PVA), and high molecular weight PVA (HMW-PVA) in prevention of aggregation and stabilization of hexameric insulin in poly(lactide-co-glycolide) (PLGA) based nanoparticle formulation. The nanoparticles were prepared using solid-in-oil-in-water (S/O/W) emulsification method with one of the said surfactant system in inner aqueous phase. The thermal unfolding analysis of released insulin using circular dichroism (CD) indicated thermal stability of the hexameric form. Insulin aggregation monitored by differential scanning calorimetry (DSC) suggested the importance of nuclei formation for aggregation and its prevention by HMW-PVA. Additional guanidinium hydrochloride based equilibrium unfolding and in silico (molecular docking) studies suggested maximum stability of released insulin from formulation containing HMW-PVA (F3). Furthermore, in vivo studies of insulin loaded nanoparticle formulation (F3) in diabetic rats showed its bioactivity. In conclusion, our studies highlight the importance of C-terminal residues of insulin in structural integrity and suggest that the released insulin from formulation containing HMW-PVA in inner aqueous phase was conformationally and thermodynamically stable and bioactive in vivo.
authors: †CSIR-Institute of Microbial Technology, Sector 39-A, Chandigarh 160036, India.
authors: Sanjay
authors: S
authors: Rawat
authors: ‡Department of Pharmacoinformatics, National Institute of Pharmaceutical Education and Research, Sector 67, Mohali 160062, India.
authors: Pawan
authors: P
authors: Gupta
authors: †CSIR-Institute of Microbial Technology, Sector 39-A, Chandigarh 160036, India.
authors: Anil
authors: A
authors: Kumar
authors: ‡Department of Pharmacoinformatics, National Institute of Pharmaceutical Education and Research, Sector 67, Mohali 160062, India.
authors: Prabha
authors: P
authors: Garg
authors: †CSIR-Institute of Microbial Technology, Sector 39-A, Chandigarh 160036, India.
authors: C Raman
authors: CR
authors: Suri
authors: †CSIR-Institute of Microbial Technology, Sector 39-A, Chandigarh 160036, India.
authors: Debendra K
authors: DK
authors: Sahoo
mesh_terms: D000178:Acrylamides / Q000737:chemistry; D000818:Animals; D002152:Calorimetry, Differential Scanning; D002417:Cattle; D002712:Chlorides / Q000737:chemistry; D002942:Circular Dichroism; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy; D005260:Female; D019791:Guanidine / Q000737:chemistry; D007328:Insulin / Q000737:chemistry*; D019344:Lactic Acid / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D062105:Molecular Docking Simulation; D008970:Molecular Weight; D053758:Nanoparticles / Q000737:chemistry*; D010179:Pancreas / Q000378:metabolism; D010316:Particle Size; D011098:Polyglactin 910 / Q000737:chemistry; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000737:chemistry; D011136:Polysorbates / Q000737:chemistry; D011142:Polyvinyl Alcohol / Q000737:chemistry*; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D051381:Rats; D017207:Rats, Sprague-Dawley; D013501:Surface-Active Agents / Q000737:chemistry; D013696:Temperature
chemical_list: D000178:Acrylamides; D002712:Chlorides; D007328:Insulin; D011108:Polymers; D011136:Polysorbates; D013501:Surface-Active Agents; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D011098:Polyglactin 910; D011142:Polyvinyl Alcohol; D019791:Guanidine
keywords: aggregation; bovine insulin; nanoparticles; poly(lactide-co-glycolide); poly(vinyl alcohol); stability