title: Preparation of gamma-PGA/chitosan composite tissue engineering matrices.
abstract: Gamma-poly(glutamic acid) (gamma-PGA), a hydrophilic and biodegradable polymer, was chosen to modify chitosan matrices to produce a gamma-PGA/chitosan composite biomaterial. Three types of both dense and porous composite matrices containing different amounts of gamma-PGA were fabricated. Chitosan and gamma-PGA matrices were also prepared as controls. Fluorescence staining indicated that chitosan and gamma-PGA were evenly distributed in the composite matrices. SEM micrographs showed that an interconnected porous structure with a pore size of 30-100 microm was present in all porous matrices except the gamma-PGA ones. By increasing the percentage of gamma-PGA from 0% to 20%, the swelling ratio of the matrices was enhanced from 1.6 to 3.2. Similarly, the contact angle of the matrices decreased from 113 degrees to 94 degrees . These data suggested that the surface hydrophilicity, water absorption rate, and swelling ratio were improved by adding gamma-PGA to the matrices. Additionally, the mechanical strength of the porous gamma-PGA/chitosan matrices was about 25-50%, higher than that of the unmodified chitosan matrices. The composite matrices were also examined and found to be an appropriate environment for cell attachment and proliferation. The cell density on the 20% gamma-PGA-modified matrices was almost triple that on the unmodified chitosan matrices on day 5. In summary, the gamma-PGA/chitosan composite matrices, due to their better hydrophilic, cytocompatible, and mechanical properties, are very promising biomaterials for tissue engineering applications.
authors.affiliation: Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan, ROC.
authors.forename: Chien-Yang
authors.initials: CY
authors.lastname: Hsieh
authors.forename: Sung-Pei
authors.initials: SP
authors.lastname: Tsai
authors.forename: Da-Ming
authors.initials: DM
authors.lastname: Wang
authors.forename: Yaw-Nan
authors.initials: YN
authors.lastname: Chang
authors.forename: Hsyue-Jen
authors.initials: HJ
authors.lastname: Hsieh
mesh_terms: D020341:Absorbable Implants; D000327:Adsorption; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D018929:Cell Culture Techniques / Q000379:methods; D045744:Cell Line, Tumor; D048429:Cell Size; D002470:Cell Survival; D048271:Chitosan / Q000032:analysis / Q000737:chemistry*; D004548:Elasticity; D005109:Extracellular Matrix / Q000737:chemistry; D008420:Manufactured Materials / Q000032:analysis; D008422:Materials Testing; D008968:Molecular Conformation; D012516:Osteosarcoma / Q000473:pathology* / Q000503:physiopathology*; D011099:Polyglutamic Acid / Q000032:analysis / Q000737:chemistry*; D016062:Porosity; D011485:Protein Binding; D051381:Rats; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D013499:Surface Properties; D013718:Tensile Strength; D023822:Tissue Engineering / Q000379:methods*; D014867:Water / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D014867:Water; D011099:Polyglutamic Acid; D012710:Serum Albumin, Bovine; D048271:Chitosan