title: Preparation and characterization of porous PDLLA/HA composite foams by supercritical carbon dioxide technology.
abstract: A composite poly(D,L)lactic acid (PDLLA)/hydroxyapatite (HA) biomaterial was prepared by in situ polymerization of D,L-lactide monomer and HA. Supercritical CO2 (SC CO2) technology was developed to prepare the biodegradable composite foams for use in tissue regeneration. In this technology, NaCl particles were used as porogen to produce an open-pore structure. Organic solvents were not used and high temperature was not necessary. The problem with pore interconnectivity was resolved. High-porosity composite foams (up to 90% +/- 2% porosity) were obtained with pore sizes ranging from 100 to 300 microm suitable for cell seeding. The microstructure and morphology of the composite foams could be controlled by saturation pressure, saturation time, and temperature as well as amount of NaCl particles. The compressive strength and water absorbability of the composite foams were also determined. With an increase in HA amount, the molecular weight of PDLLA/HA composite foams decreased, but the mechanical strength and hydrophilicity increased slightly.
authors.affiliation: Institute of Nano and Bio-Polymeric Materials, School of Materials Science and Engineering, Tongji University, Shanghai 200092, People's Republic of China. txr@mail.tongji.edu.cn
authors.forename: Xinrong
authors.initials: X
authors.lastname: Teng
authors.forename: Jie
authors.initials: J
authors.lastname: Ren
authors.forename: Shuying
authors.initials: S
authors.lastname: Gu
mesh_terms: D001672:Biocompatible Materials / Q000138:chemical synthesis / Q000737:chemistry*; D002245:Carbon Dioxide / Q000737:chemistry; D020770:Compomers / Q000138:chemical synthesis / Q000737:chemistry*; D019245:Compressive Strength; D017886:Durapatite / Q000737:chemistry*; D019344:Lactic Acid / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D008970:Molecular Weight; D011091:Polyesters; D011108:Polymers / Q000737:chemistry*; D016062:Porosity; D012038:Regeneration; D012965:Sodium Chloride / Q000737:chemistry; D012997:Solvents; D013696:Temperature
chemical_list: D001672:Biocompatible Materials; D020770:Compomers; D011091:Polyesters; D011108:Polymers; D012997:Solvents; D002245:Carbon Dioxide; D019344:Lactic Acid; D012965:Sodium Chloride; C033616:poly(lactide); D017886:Durapatite