Impartment of uptake and release functions to colagens and its application to dentin adhesion

本项目的目的是建立吸收和控制释放客体分子进入/从宿主生物聚合物，如胶原蛋白，是在活体丰富的方法。本研究旨在探讨牙本质胶原中抗菌剂或粘附成分在体内和原位可控释放的可能性。首先，采用戊二醛交联明胶制备牙本质胶原模型。戊二醛浓度越高，比表面积越大，变性温度越高，表明交联程度越高。然后以肌腱胶原、皮肤胶原膜和乙酰纤维素膜为主体聚合物，以亚甲蓝、吖啶橙子和吖啶黄为客体分子，制备了一系列具有生物活性的复合材料。乙醇水溶液用作聚合物凝胶的挤压剂。系统地测量摄取和释放的量。乙酰纤维素膜比胶原材料吸收更多的染料，而胶原材料的释放效率更高。释放受乙醇浓度的调节，说明本研究中的控释作用主要是由于渗透压引起的凝胶崩解。在此基础上，将实现更先进的控制，其中考虑了由pH或温度条件引起的体积相变现象，或主客体之间的静电/疏水相互作用。

The aim of this project was to establish the method of uptake and controlled release of guest molecules into/from host biopolymers, such as collagen that is rich in the living body. The possibility of the controlled in vivo and in situ release of some antibacterial agents or adhesive components from dentinal collagen was examined.First, model collagen was prepared by cross-linking gelatin using glutaraldehyde, under various conditions. The higher concentration of glutaraldehyde resulted in a larger specific surface area and a higher denaturation temperature, suggesting the more cross-linked structure. Methylene blue was lead into these materials and was released by the addition of ethanol or saline solution.Next, tendon collagen, skin collagen films and acetylcellulose films were chosen as host polymers and methylene blue, acridine orange and acriflavine as guest molecules. Aqueous ethanol was used as squeezer of polymer gels. The amount of uptake and release was measured systematically. More dyes were taken into acetylcellulose film than into collagen materials, while release efficiency was higher for the collagens. The release was regulated by the concentration of ethanol added.It was suggested that the controlled release in this study was mainly due to the osmotic pressure that caused the collapse of polymer gels. On the basis of this study, more advanced control will be realized, in which the volume phase transition phenomena caused by pH or temperature condition, or electrostatic/hydrophobic interactions between host and guest are considered.