Search Results (2)

The cross-linking point of a conventional chemical cross-linking agent is fixed. Therefore, gels that are prepared with a conventional cross-linking agent have poor deformability, strength, shear resistance, and further properties. Some researchers have prepared a new cross-linking agent using cyclodextrin (CD). In a polyrotaxane cross-linking agent, the cross-linking points can slide freely along the molecule chain. The special “slide ring” structure can provide better elongation, strength, and other properties to gels, which can effectively expand the application of the gel’s materials. This paper summarizes the preparation methods and applications from different types of CD and compares the improvements of properties (swelling, viscoelastic properties, etc.). In addition, the current results of our group are presented, and some ideas are provided for the development of polyrotaxane cross-linking agents. Full article

The cytocompatibility of biological and synthetic materials is an important issue for biomaterials. Gelatin hydrogels are used as biomaterials because of their biodegradability. We have previously reported that the mechanical properties of gelatin hydrogels are improved by cross-linking with polyrotaxanes, a supramolecular compound composed of many cyclic molecules threaded with a linear polymer. In this study, the ability of gelatin hydrogels cross-linked by polyrotaxanes (polyrotaxane–gelatin hydrogels) for cell cultivation was investigated. Because the amount of polyrotaxanes used for gelatin fabrication is very small, the chemical composition was barely altered. The structure and wettability of these hydrogels are also the same as those of conventional hydrogels. Fibroblasts adhered on polyrotaxane–gelatin hydrogels and conventional hydrogels without any reduction or apoptosis of adherent cells. From these results, the polyrotaxane–gelatin hydrogels have the potential to improve the mechanical properties of gelatin without affecting cytocompatibility. Interestingly, when cells were cultured on polyrotaxane–gelatin hydrogels after repeated stress deformation, the cells were spontaneously oriented to the stretching direction. This cellular response was not observed on conventional hydrogels. These results suggest that the use of a polyrotaxane cross-linking agent can not only improve the strength of hydrogels but can also contribute to controlling reorientation of the gelatin. Full article