Development of a new poly(ethylene glycol)-graft-poly(D,L-lactic acid) as potential drug carriers

• Published in: Journal of Biomedical Materials Research Part B Vol. 89A; no. 1; pp. 160 - 167
• Main Authors: Pan, Jun, Zhao, Mingmei, Liu, Ying, Wang, Bin, Mi, Li, Yang, Li
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.04.2009
• Subjects: Adsorption; Animals; Biocompatible Materials - chemistry; Cell Adhesion; Cell Proliferation; Cells, Cultured; Drug Carriers - chemistry; drug delivery; Drug Delivery Systems; graft; L-lactic acid; Lactic Acid - chemistry; Materials Testing; Molecular Structure; Osteoblasts - cytology; Osteoblasts - physiology; Particle Size; poly(D; poly(D,L‐lactic acid); poly(ethylene glycol); Polyesters; Polyethylene Glycols - chemistry; Polymers - chemistry; Rats; Rats, Wistar; Serum Albumin, Bovine - chemistry
• ISSN: 1549-3296; 1552-4965; 1552-4981
• DOI: 10.1002/jbm.a.31965

A new poly(ethylene glycol) (PEG)‐modified poly(D,L‐lactic acid) (PLA) was synthesized by grafting maleic anhydride onto PLA and subsequently amidating with O,O'‐bis‐(2‐aminopropyl) polypropylene glycol‐block‐polyethylene oxide‐block‐polypropylene glycol (H2 N‐PEG‐NH2, Mw: 600). Its structure was confirmed by FTIR, DSC, 1H NMR, GPC, and ninhydrin test. The polymer is more hydrophilic compared with PLA according to contact angle tests, and is degradable as determined from its pH and mass changes during degradation. The polymer shows a 62.7% decrease in BSA absorption compared with PLA when dried in air, and a 82.76% decrease when dried under 65% humidity, as measured by fluorospectrophotometry. The polymer promotes adhesion and proliferation of osteoblasts, determined by MTT assay. With this new polymer, spherical nanoscale aggregates encapsulated with or without hydrophilic dye are formed spontaneously in water, visualized by inverted microscope and AFM. The particle size is concentration dependent as confirmed by dynamic light scattering, and its critical micelle concentration was 1.124 μg/mL as determined by a fluorescence method. The good hydrophilicity, degradability, cellular compatibility, protein‐resistance, self‐aggregation, and reactivity of the polymer may lead to its potential applications in drug delivery. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009