Properties, Fabrication And Investigation Of Polyaniline And Zein Conduits In Nerve Injury

The main contents of the thesis are as follows:PART 1: In vitro expansion of Schwann cells from the predegeneratedsciatic nerves of adult SD rat. This part was a prepation of seeding cells forlater investigaion.PART 2: Evaluation of polyaniline (PANi) as implanted electrodecoatings. It revealed that 1) PANi was in situ polymerized on platinum (Pt)electrodes with nanoparticles from 20nm to 40nm; 2) in long-term electricalstimulation model, PANi coatings showed excellent anticorrosion propertyduring 6 months electrical stimulation, as well as the intactness and thestability; 3) in SD rat retinal homogenate stimulation model, PANi coatingsdramatically protected electrodes and surrounding tissue against nonspecificadsorption and peroxidation, respectively.PART 3: The fabrication and the investigation of zein conduits in SD rat5mm sciatic nerve regeneration.The first part was the fabrication and characterization of zein conduits,focus on the conductivity, permeability, bioactivity, mechanical property, etc.The zein conduits and its fabrication were applied China Patent. It indicatedthat 1) zein and its degraded products are biocompatible on PC12 cells; 2) zein conduits were selectively permeable; inner surface coated withnanoscaled microspheres, which was releasable; mechanical property wassuitable for operation and implant; 3) the conductivity of zein conduits wasobtained from PANi coating. PANi are biocompatible on PC12 cells, ratherthan its degraded products, which hamper the cell proliferation in specificcontent; 4) the bioactivity was obtained from implant cells or ECM.The second part was the evaluation of non-bioactive conductive zeinconduits in SD rat model with 5mm sciatic nerve gaps. It showed thatregenerated axons accomplished to connect the distal nerve ends in 4 weeksin both zein conduits and conductive zein conduits. It was feasible inperipheral nerve restoration.The innovations were mainly in two aspects:1. Utilization of PANi as coating materials to the implanted electrodes. Itis the first time to evaluate the PANi coating properties in SD rat retinalhomogenate model.1) The morphology of PANi coating was nanoparticles ranging from20nm to 40nm, which exhibited excellent properties on stability;2) In long-term electrical stimulation system, the PANi coating showedsplendid anticorrosion property in long-term electrical stimulation, as well asthe intactness and the stability;3) In the SD rat retinal homogenate electrical stimulation model, thePANi coatings dramatically protected electrodes against nonspecificadsorption, which reduced the inflammation, as well as the protection ofsurrounding tissue from peroxidation.2. It is firstly to introduce zein into peripheral nerve restoration tofabricate nerve conduits. The zein conduits and its fabrication method were applied China Patent.1) Zein conduits were biocompatible and biodegradable. PC12 cells relyon the zein degraded products.2) The procedure of fabrication of zein conduits was simple and wideuse, which could obtain conduits with controllable inner dimmers (>0.28μm),length and depth (>18μm) for tissue engineering.3) Combined zein with PANi to obtain conductive zein conduits, firsly,for nerve repair and restoration.