A proteomics study to explore the role of adsorbed serum proteins for PC12 cell adhesion and growth on chitosan and collagen/chitosan surfaces

The aim of this article is to apply proteomics in the comparison of the molecular mechanisms of PC12 cell adhesion and growth mediated by the adsorbed serum proteins on the surfaces of chitosan and collagen/chitosan films.First,the chitosan and the collagen/chitosan films were prepared by spin coating;and their surface morphologies were characterized by scanning electron microscopy,X-ray energy dispersive spectroscopy,contact angle measurement and Fourier transform infrared spectroscopy.Subsequently,cell proliferation experiments on two materials were performed and the dynamic curves of protein adsorption on their surfaces were measured.Then,proteomics and bioinformatics were used to analyze and compare the adsorbed serum proteins on the surfaces of two biomaterials;and their effects on cell adhesion were discussed.The results showed that the optimum concentration of chitosan film was 2%w/v.When compared with chitosan film,collagen/chitosan film promoted the growth and proliferation of PC12 cells more significantly.Although the dynamic curves showed no significant difference in the total amount of the adsorbed proteins on both surfaces,proteomics and bioinformatics analyses revealed a difference in protein types:the chitosan surface adsorbed more vitronectin whereas collagen/chitosan surface adsorbed more fibronectin 1 and contained more cell surface receptor binding sites and more Leu-Asp-Val sequences in its surface structure;the collagen/chitosan surface were more conducive to promoting cell adhesion and growth.

Effects of Shenlian Extracts (参莲提取物) on Atherosclerosis by Inhibition of the Inflammatory Response

Objective: Inflammation plays a critical role in atherosclerosis, and this inflammatory reaction is being intensively studied. Shenlian Extracts (参莲提取物), an active ingredient of Chinese medicinal herbs, is believed to have multiple therapeutic and preventive effects against human vascular diseases, including atherosclerosis. Our work investigated whether Shenlian Extracts serves as an anti-inflammatory agent during atherogenesis. Methods: We established a model of atherosclerosis in rabbits using balloon angioplasty and a high cholesterol diet. The effects of Shenlian Extracts on vessel structure and inflammation were assessed by hematoxylin-eosin staining of the femoral artery, measurement of inflammation-related factors in serum or vascular tissue, and radioimmunoassay. Enzyme linked immunosorbent assays (ELISA), flow cytometry and western blots were also performed. Results: We show that oral pre-treatment with Shenlian Extracts suppressed the pathological changes associated with atherosclerosis and that graded doses of Shenlian Extracts reduced total serum levels of cholesterol (90, 180 and 360 mg/kg), triglyceride (180 and 360 mg/kg), and LDL-c (90, 180 mg/kg). Various doses of Shenlian Extracts reduced serum content of TNF-α (180 and 360 mg/kg), CRP (90, 180 and 360 mg/kg) and IL-8 (360 mg/kg) (P<0.05), but led to no significant changes in IL-1β levels. Treatment with Shenlian Extracts also significantly reduced VCAM-1 levels (90 and 360 mg/kg) and IGF-1 levels (90 and 180 mg/kg) in vascular tissue but had no significant effect on ICAM-1 and MCP-1 levels. Finally, Shenlian Extracts significantly reduced the abnormal expression of CD18 in monocytes in a dose-dependent manner. Conclusion: These results suggest that Shenlian Extracts may play a direct role in preventing and treating atherogenesis by inhibiting the inflammatory reaction, providing insights into the possible mechanism underlying the anti-atherosclerotic actions of Shenlian Extracts.

Fabrication and functional characterization of engineered features on pyrolytic carbon

Engineered features on pyrolytic carbon （PyC） have been reported to improve the functional performance of the bio-implants. This paper is focused on the functional characterization of micro-features created on the surface of PyC. Two different types of micro-features （wide channels and arrayed holes） have been created by micro-electrical discharge machining （micro-EDM）. Two other micro-fea- tures （fine channels and micro-pillars） have been created by micromilling process. Coliform bacterial strain was iso- lated from a sample of water and grown on all four tex- tured. Cell growth was carried out on an unmachined surface to see the behavior of the isolated bacterial strain on the textured/non-textured surfaces. The samples were examined under SEM before and after wash to see cell growth and cell adhesion capability of the textures. The wide channels by micro-EDM show the maximum cell growth but poor cell adhesion. 184% higher cell growth has been observed on the wide channels in comparison with unmachined surface. The fine channels by micro-milling show comparatively lower growth but the cell adhesion on this surface was found excellent. 71% cells remain unwa- shed after washing of the surface having fine channel textures. It means that the channels structure shows the maximum cell growth and adhesion independent of machining process.