Cells Induced Mineralization Of Liquid Crystalline Collagen

Natural bone tissue is a natural composite materials with perfect hierarchies.Under the effect of osteoblast, nano Hydroxyapatites(HA) which grow along the C axis orientation parallel to the direction of the collagen fibers and orderly together form a special senior self-assembled structures, so that the natural bone has good compressive or tensile and other physical properties and biological performance.Under the action of osteoblasts in vitro, the simulation of natural bone ossification of physical environment, thereby system to study the essence of bone formation and the relationship between the structure and performance, to design high-performance imitation bone materials is of great significance.To simulate natural bone mineralization process, based on the calcium glycerophosphate(Glycerol phosphate calucium salt, GPC) for calcium phosphorus source, with Type I collagen(Type I collagen, Col I) for macromolecular matrix material, in Alkaline phosphatase, Alkaline phosphatase, ALP) or precursor under the action of osteoblast, through the Sol- Gel phase transition method and cell mineralization induced mineralization, the method of building the nano HA/Col composite materials.On the one hand, from the perspective of bionics, the preparation of liquid crystal collagen membrane: using polarization microscope, scanning electron microscopy(sem) and atomic force microscopy study of collagen membrane liquid crystal texture and topology.By XRD, SEM, EDS and TEM observation test of GPC-Col- ALP mineralization system of comprehensive evaluation, to explore the calcium phosphate inorganic minerals in the process of liquid crystal state on collagen matrix deposition and its mechanism.On the other hand, with methods of MTT method,electron microscope, cytoskeleton fluorescence staining, osteocalcin dyeing, Von Kossa staining, alkaline phosphatase staining,study the effect of GPC mineralization system on the proliferation, growth morphology and cytoskeleton of mouse precursor osteoblast(MC-3T3-E1) cells. Results show that the ALP can ionize the GPC phosphate ester bond, thus make the GPC parsing out PO43- and Ca2 +, hydroxyapatite formates under the condition of weak alkaline and body temperature.Besides,collagen has the effect to promote the system of mineralization. The calcium phosphate mineralized medium of low concentration had the function of promoting the proliferation and growth of MC-3T3-E1 cells, and inhibited the proliferation and growth of cells after 15mmol/L concentration. GPC can promote bone ALP secretion, within a certain concentration range.with the increase of the concentrations of GPC, it increase the activity of alkaline phosphatase(ALP), ALP activity was the highest when GPC with the concentration of 15 mmol / L. With the increase of the concentration of GPC, ALP activity decreases gradually.