Electrospun Electroactive Poly-(o-methoxyaniline)/Gelatin Fibers with Potential Application in Tissue Engineering

Autor: Kuan-Yi Lin, 林冠鎰
Rok vydání: 2012
Druh dokumentu: 學位論文 ; thesis
Popis: 100
Composite scaffold prepared by electrospinning technology can provide extracellular matrix-like environment, large surface area, high porosity, and multifunctionality, thus increases their application in tissue engineering. The purpose of this study was to enhance the biocompatibility of electrospun poly(o-methoxyaniline) (POMA) fibers and to explore its potential for tissue engineering application. Average molecular weight of POMA synthesized in this study was 45880 Dalton. Viscosity of the solution for electrospinning increased rapidly to 71.9 cP within 20-min mixing. The optimal concentration of POMA for electrospinning nanofibers was 5 % (w/v). POMA/gelatin (PG) electrospun fibers were successfully prepared using a mix of 5 % (w/v) POMA and 17 % (w/v) gelatin in a volume ratio of 70:30. Eletrospinning mats (PGC) with conductivity was made when doped with 5 % (w/v) citric acid. The average diameters of POMA, PG, and PGC nanofibers were 356±58, 306±55, and 269±40 nm, respectively. Contact angle of POMA was 109±2o, and those of PG and PGC were 0o. After crosslinking, contact angles of PGE and PGCE were 28±3o, and 30±3o, respectively. The degrees of crosslinking for PGE and PGCE were 64.23±7.41 % and 74.11±1.44 %, respectively. The maximal temperature of weight loss increased 15-20 oC after crosslinking. Cyclic voltammetric analysis found that POMA, PGE and PGCE had redox capability. Only doped PGC and PGCE had measured conductivity of 3.31±0.19 x 10-5 and 5.85±0.49 x 10-6 S/cm, respectively. Compared to undoped PG, the absorption wavelengths of 316 and 623 nm corresponding to benzene ring and the quinone ring of POMA were red-shifted to 424 and 760 nm in PGC, which further validated citric acid doping could change the state of POMA from emeraldine base to emeraldine salt. POMA nanofibers were non-biodegradable. PGE and PGCE nanofibers were biodegradable where fibrous morphology maintained for 1 and 8 days. Human adipose stem cells (hASCs) and rat cardiac myoblast (H9c2) showed improved attachment and proliferation on PGE and PGCE compared to POMA nanofibers. Furthermore, applied electric field could increase cell length as well as the cell polarization of hASCs, and enhance the differentiation ability of H9c2 cells into myotubes. In summary, citric acid doped nanofibers of POMA blended with gelatin were found to exhibit improved biocompatibility and could be applied in tissue engineering in the future.
Databáze: Networked Digital Library of Theses & Dissertations
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