title: Encapsulation of proteins in biodegradable polymeric microparticles using electrospray in the Taylor cone-jet mode.
abstract: Solvent extraction (or evaporation from a W(1)/O/W(2)-dispersion), coacervation, and spray drying methods are commonly employed to encapsulate protein drugs in polymeric microparticles for sustained delivery applications. To overcome the limitations of these methods, a novel electrospray method was developed to encapsulate a model protein drug-bovine serum albumin (BSA) in biodegradable polymeric microparticles and examine the feasibility of the process in not denaturing the protein. Microparticles of approximately 20 microm diameter with corrugated surfaces and smooth surfaces were observed by scanning electron microscope. Confocal laser scanning microscope images showed that BSA was distributed evenly in microparticles. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was employed to investigate the protein integrity of BSA released from the polymer matrix after 38 days. No protein degradation was observed during the 38 days release. The secondary structure of released BSA was characterized by Fourier transform infrared (FTIR) and circular dichroism (CD), which suggested that the released BSA was almost identical to native BSA. The encapsulation efficiency could reach 76% by adjusting the amount of the additive Pluronic F127 and processing parameters. The release profile could be tailored by the fabrication process and the sustained release of BSA could endure for more than 1 month. More than 80% of the bioactivity of BSA (evaluated by BSA ELISA kit) could be maintained after releasing from polymer matrix. Findings of the present study demonstrate that this novel electrospray method is a promising approach to encapsulate bioactive materials such as proteins, enzymes, antibiotics, and DNA fragments in biodegradable polymeric particles.
authors.affiliation: Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117576.
authors.forename: Jingwei
authors.initials: J
authors.lastname: Xie
authors.forename: Chi-Hwa
authors.initials: CH
authors.lastname: Wang
mesh_terms: D020341:Absorbable Implants; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D003692:Delayed-Action Preparations / Q000737:chemistry*; D004058:Diffusion; D004337:Drug Carriers / Q000737:chemistry*; D004339:Drug Compounding / Q000379:methods*; D004355:Drug Stability; D004563:Electrochemistry / Q000379:methods; D005240:Feasibility Studies; D044085:Microfluidics / Q000379:methods; D008863:Microspheres; D010316:Particle Size; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D052616:Solid Phase Extraction / Q000379:methods; D013499:Surface Properties
chemical_list: D020099:Coated Materials, Biocompatible; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D012710:Serum Albumin, Bovine