Fabrication Of Films That Increase The Adhesion Of Coral Cells

The coral reef ecosystem is one of the richest and most diverse ecosystems on earth.It can expand the land area,store fresh water resources and provide important value for medical development.At present,coral reefs are facing challenges from both human activities and natural changes,and their ecological value has suffered an unprecedented loss.Coral cells are the most basic unit of coral reef system.Therefore,it is of long-term significance to explore the mechanism contributing to the growth of coral cells.A series of films were prepared by Lb L(layer-by-layer assembly)technology and used as substrate coatings for coral cells.In addition,different methods of persistent adhesion between coatings and substrates were studied.The main research work is shown below:(1)Chitosan(CS)and dialdehyde starch(DAS)were prepared into self-healing films based on Schiff base system by Lb L technology.The method of polydopamine modification was proposed to improve the adhesion between the film and the substrate surface.After that,the morphology and properties of composite films before and after modification were characterized.The(CS/DAS)_n films were prepared on the substrate surface with different concentration gradients.Substrates with multiple layers of films are used in cell culture.The cytotoxicity and cell adhesion of the modified film to NHDFs were first studied due to the lack of relevant studies on the culture conditions of coral cells.The results showed that the film had no cytotoxicity to NHDFs and could promote the adhesion and growth of cells on the substrate surface.The films were then applied to coral cells,which were induced to separate in vivo and cultured in vitro.After the cells were inoculated into the(CS/DAS)_nfilms,the results showed that the cells had favourable biological activity.(2)The self-healing film(CS/DAS)_n was modified based on phase transformation lysozyme(PTL)to improve the adhesion of the film on the substrate.The surface morphology and self-healing efficiency of the modified films were characterized.The adhesion between film and substrate was improved after PTL modification.Different concentration gradients(CS/DAS)_n-PTL were fabricated for the culture of common cell NHDFs and coral cells,and then the cell biological activity in the membrane was evaluated.When the concentration of CS was 6 mg/m L and the concentration of DAS was 5 mg/m L in the composite membrane after modification,the fluorescence intensity of coral cells was the highest.The improvement of cytocompatibility was more obvious than that of the polydopamine modified composite film.(3)Based on the principle of surface catalyzed oxidation radical,the modified(CS/DAS)_nself-repairing coating was prepared on the surface of ferroalloy substrate to improve the adhesion of the coating on the substrate.The morphology of the modified coating was characterized with SEM,and the adhesion test results showed that the modified coating adhered more firmly on the surface of the ferroalloy.In addition,the ferroalloy substrate coated with(CS/DAS)_n was used for coral cell culture,which greatly improved the biocompatibility of ferroalloy substrate.The above work results have proved that the fabricated layer-by-layer assembled composite films have both self-healing function and biocompatibility,which make the Lb L films expected to play an important role in the field of biological coating.