title: Chitosan modified poly(L-lactide) microspheres as cell microcarriers for cartilage tissue engineering.
abstract: The surfaces of poly(L-lactide) (PLLA) microspheres were modified by chitosan via a method of hydrolysis and grafting-coating to improve their compatibility to chondrocytes. The PLLA microspheres with a diameter of 74-150 microm were fabricated by an oil/water emulsion solvent evaporation method, followed by hydrolysis in alkaline solution to produce a larger number of carboxyl groups. Using water-soluble carbodiimide as a coupling reagent, chitosan was covalently grafted onto the microspheres. Due to the physical entanglement and insolubility at neutral pH, unbonded chitosan molecules were stably remained to yield a large amount of coated chitosan. Biological performance of the control PLLA and the chitosan-coated PLLA microspheres were assessed by in vitro culture of rabbit auricular chondrocytes. After 24h and 7d culture, the chitosan-coated PLLA microspheres, especially the ones with larger chitosan amount, exhibited stronger ability to promote cell attachment and proliferation, and maintain the secretion function of the chondrocytes. Therefore, the chitosan-coated PLLA microspheres can be potentially used as the injectable cell microcarriers for chondrogenesis in cartilage tissue engineering.
authors.affiliation: Key Laboratory of Macromolecular Synthesis and Functionalization, Ministry of Education, and Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, China.
authors.forename: Lihong
authors.initials: L
authors.lastname: Lao
authors.forename: Huaping
authors.initials: H
authors.lastname: Tan
authors.forename: Yingjun
authors.initials: Y
authors.lastname: Wang
authors.forename: Changyou
authors.initials: C
authors.lastname: Gao
mesh_terms: D000818:Animals; D002448:Cell Adhesion / Q000502:physiology; D018929:Cell Culture Techniques; D049109:Cell Proliferation; D048271:Chitosan / Q000737:chemistry*; D019902:Chondrocytes / Q000737:chemistry* / Q000502:physiology; D004425:Ear Cartilage / Q000737:chemistry* / Q000166:cytology; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008863:Microspheres; D009821:Oils / Q000737:chemistry; D010316:Particle Size; D011091:Polyesters / Q000737:chemistry*; D011817:Rabbits; D012997:Solvents / Q000737:chemistry; D013499:Surface Properties; D023822:Tissue Engineering / Q000379:methods; D014867:Water / Q000737:chemistry
chemical_list: D009821:Oils; D011091:Polyesters; D012997:Solvents; D014867:Water; C033616:poly(lactide); D048271:Chitosan