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Collagen I is the main component of protein in bone and exhibits many excellent applications in biomedical fields. Gellan gum possesses good biocompatible, biodegradable and good mechanical property, and shows great potentials as tissue engineering scaffold or cell culture substrate. Therefore, the aim of this study was to use collagen I, gellan gum and β-TCP to prepare collagen I/gellan gum/β-TCP microspheres by emulsion method as bone graft substitute materials. The preliminary results showed that collagen I/gellan gum/β-TCP microspheres had particle size distribution between 500-1000 μP in diameter and exhibited better mechanical strength. These microspheres also showed good biocompatibility in cell activity test.

Epidermal growth factor receptor (EGFR) is an important target on cancer therapy. One of the approaches is to modulate EGFR induced ligand-binding affinity change. In order to understand the correlation between ligand-binding change and EGFR modulation, we try to get some small molecular agents from traditional Chinese medicines (TCMs) to modulate EGFR activity on the biosensor system. Among 60 of TCMs, we find that some samples exhibit different influence on EGFR modulation. Among these, 051 showed a more inhibitive property due to decreasing EGF-affinity, -binding to EGFR and existed an anti-EGFR activity to A549 cells. On the other hand, 040 exist opposite function to 051. 040 is a most powerful enhancer that can increase the affinity and quantity of EGF binding to EGFR and a pro-EGFR activity on cell culture system. In our study, we can successfully regulate the EGFR-mediated cell proliferation and anti-apoptosis by modulating the affinity of EGF-EGFR interaction. This way will be a useful method to apply on the therapy of human diseases.

The purpose of this study was to prepare and evaluate the feasibility and cytocompatibility of a composite (GTG) as a large defect bone substitute. The composite is combined with tricalcium phosphate ceramic particles and glutaraldehyde cross-linked gelatin. The cytotoxicity of the GTG composite were examined by extracts cocultured with rat osteoblasts in vitro. The results of extracts cocultured with osteoblasts showed that the extracts obtained from the 2%, 4%, acid 8% GTG composites after soaked for 4 days were to inhibit the growth of osteoblasts. After being soaked for 4-7 days, the cell numbers were quickly increasing with the soaking time, and then the cell number almost reached a plateau after 14-day soaking period. In the analyses of substances released from the GTG composites, the authors found that the GTG composites were gradually releasing some nutritious elements containing gelatin and calcium.

A 10-mm gap of rat sciatic nerve was created between the proximal and distal nerve stumps, which were sutured into silicone rubber tubes filled with an extracellular gel containing collagen, laminin and fibronectin. Empty silicone rubber tubes were used as controls. Six weeks after implantation, all extracellular elements were completely degraded and absorbed, and 90% of the animals from the extracellular gel group exhibited regeneration across the nerve gaps, whereas only 60% in the control group. Histology of the regenerated nerves revealed that a more mature ultrastructural organization with 28% larger cross sectional area and 28% higher number of myelinated axons in the extracellular gel group than the controls. These results showed that the gel mixture of collagen, laminin and fibronectin could offer a suitable growth medium for the regeneration of axons.