METHYL CELLULOSE ENHANCE GELATIN MEMBRANE AS GUIDANCE CHANNELS FOR PERIPHERAL NERVE REGENERATION

Background: The methyl cellulose could successfully be transferred into 2,3-dialdehyde cellulose by using sodium periodate as an oxidant. 2,3-dialdehyde cellulose can cross-link gelatin without adding any other cross-linking agent. We hope the dialdehyde cellulose-gelatin membrane could enhance the physical properties of gelatin membrane by using glutaraldehyde as a cross-linker. Methods: The methyl cellulose could be successfully transferred into 2,3-dialdehyde cellulose by using sodium periodate as an oxidant. The biological stability of 2,3-dialdehyde cellulose was improved by cross-linking with gelatin. To estimate the properties of the DAC-Gel membrane with different conditions, the methyl cellulose was oxidized by different concentration of sodium periodate. After oxidized, the dialdehyde cellulose with different degree of oxidation was fabricated. FTIR could further confirm the formation of aldehyde group and the quantification of aldehyde group showed that the concentration of sodium periodate was the dominant factor to the degree of oxidation. Assessment of cross-linking degree helped us to observe the reaction between aldehyde group and amine group. The degradation test was estimated by two methods to confirm the accuracy of experiment. The hydrophilic/hydrophobic surface after cross-linking was evaluated by water contact angle test. The wettability of membrane influenced the growth of PC-12 cell. After the physical properties of membrane were established, the bio-compatibility was measured by two different methods. One of the methods based on ISO 10993. The other method is that cell seeding on the membrane. The bio-compatibility was evaluated by WST-1 and LDH. Result: Methyl cellulose was successfully converted into 2,3-dialdehyde cellulose by sodium periodate and the concentration of oxidant was the most important factor to the formation of aldehyde group. The formation of aldehyde group was directly proportional to the concentration of oxidant. Basic assessment of cross-linking degree showed that steric hindrance could be the factor to hinder cross-linking. The 2,3-dialdehyde cellulose/gelatin membrane could prolong the degradation time in 37°C. According to water contact test, the dialdehyde cellulose/gelatin membrane showed a more hydrophilic than gelatin membrane using glutaraldehyde as a cross-linker and the hydrophilic surface provided a better place for the growth of PC-12 cell. The dialdehyde cellulose/gelatin membrane using glycine to block the residual aldehyde group showed a low cytotoxicity. Conclusion: This study indicates that 2,3-dialdehyde cellulose/gelatin membrane could prolong the degradation time in 37°C and the 2,3-dialdehyde cellulose/gelatin membrane provide a better place for the growth of PC-12.