Novel nerve regeneration conduits made by different ratios of poly (L-lactide-co-glycolide) forming with porous and multi-layered structure

• Main Authors: Chih-Ling Huang, 黃芷翎
• Other Authors: Jiunn-Der Liao
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/05049606043726968542

碩士 === 國立成功大學 === 材料科學及工程學系碩博士班 === 93 === 　　Nerve bridging is suture a biomaterial-made conduit and to overpass the damaged nerve end to end with microsurgery. Peripheral nerve could be bridged between the proximal nerve and the distal stump to restore the function. Nerve conduits could eliminate tension at the healing site and induce the regeneration of axons. Nerve conduits also could permit neurobiological recovery to enhance neural regeneration and stop cells and their secretions from obstructing neural regeneration. In this study, we used poly L-latcide (PLLA), poly DL-latcide-co-glycolide 75:25 (PLGA7525) and poly DL-latcide-co-glycolide 50:50 (PLGA5050) during citric acid inducing ammonium bicarbonate gas forming process to form porous polymer film, and rolled the porous polymer film to make nerve conduits with pores and multi-layered. Electron Spectroscopy for Chemical Analyzer (ESCA) and Attenuated Total Reflectance – Fourier-Transform Infrared Spectrometer (ATR-FTIR) were employed for determining elements’ functionabilities and chemical compounds. Charge Coupled Device camera (CCD camera) and Scanning Electron Microscope (SEM) were employed for macroscopic and microscopic morphologies and structural observation. Differential Scanning Calorimetry (DSC) was employed for measuring glass-transition temperature (Tg). Nano-indentation system was employed for measuring elastic modulus and hardness. Biodegradation and water absorption ratios were measured to analyze their chemical properties and SEM was employed for microscopic morphology of the tested nerve conduit. Experiment results demonstrated that during citric acid inducing ammonium bicarbonate gas forming process, no salts (ammonium bicarbonate) remained, while Tg of PLGA5050 was lower than human body temperature. The porous structures of PLGA5050 conduit were dissolved into a condensed morphology after 28 testing days, while the material was completely degraded after 56 testing days. The degradation of PLGA7525 conduit was relatively slow, while the porous structures slightly changed their shapes after 56 testing days. Using citric acid inducing ammonium bicarbonate gas forming and unique rolling process, PLLA is relatively suitable to make multi-layered nerve conduits, which provide highly porous structures with many round openings. In addition, the porous structures with channeling characteristic can be preserved to 56 testing days.