| Summary: | 碩士 === 中國醫藥大學 === 中國醫學研究所碩士班 === 94 === This study attempted to understand how different drying methods, including oven-drying (80℃), room temperature-drying (25℃) and freeze-drying (-20℃) methods affected the characteristics of biomaterials. Physical behaviors, mechanical properties, chemical characteristics and biocompatibility of genipin cross-linked gelatin film after drying using the three different methods were investigated.
As a result, scanning electron microscopy (SEM) images showed the oven-dried films had a fusion-like appearance in their cross section. By comparison, a flat surface morphology was seen in the materials dried by the room temperature-drying method. As for the materials dried by the lyophilizer, their cross sections became highly porous. Differential scanning calorimetry (DSC) measured the glass transition temperature and melting point of those post-dried films from high to low was the oven-drying, the lyophilizer and following the room temperature-drying method. As for the tensile test, the tensile strength from high to low was the oven-drying, the room temperature-drying and following the lyophilizer method. However, the tensile elongation from high to low was the room temperature-drying, oven-drying and the lyophilizer method. Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectrometer showed that there were no significant differences in functional groups among the materials dried by the three different methods. This result suggested that there could be a denaturation-renaturation procedure in the oven-dried material and the stability of the intrahelical and interhelical crosslinks of collagen-like triple helix in the material had been damaged. As for the lyophilizer-dried process, ice crystallites were formed while freezing which increased the concentration and the viscosity of the solute. Sublimation of the ice crystallites could destroy the crosslinks between the collagen-like triple helix. However, the stability of the intrahelices and interhelices of collagen-like triple helix were improved and the helices were tightly connected. By comparison, characteristics of materials dried by the room temperature-drying method were well retained.
To evaluate the biodegradation and biocompatibility of the dried genipin cross-linked gelatin films, they were implanted subcutaneously. After 4 weeks, the flat square films became olive-like and spinle-like after drying by the oven and the room temperature-drying method, respectively. Intermediate shapes were seen for the films dried by the lyophilizer. As for the biocompatibility, a thinner fibrous capsule was seen surrounding the film dried by the room temperature-drying method as compared to that dried by the other two methods.
|
|---|
