Study On Bioinspired Nano-micro Multiscale Patterned Biomaterials Based On Superhydrophilic-superhydrophobic Template

With the development of regenerative medicine,the interaction between cells and biological materials environment has become a very important research field.The related research results contribute to the design and fabrication of new biomimetic materials.It is a key point to process cell culture substrate in the field of cell micropatterning.With the development of microelectronics technique,micropatterned biomaterials have attracted many researchers.The surface microscopic features of the biomaterials are constructed by surface fine design and modification in order to lead and control the cell growth behavior effectively,confine cells in a defined spatial position thus forming cell micropatterning.Cell micropatterning technology has been widely used in the field of biology,and has broad application prospects in the fields of biosensors,drug screening,cell basic biology and tissue engineering.In most studies on cell micropatterning,cells are usually immobilized on single scale microscale pattern or nanoscale pattern.While the researches of micro-nano structures in the micro-regions of materials are less.However,a large number of studies indicated that the micro-nano structures of materials play an important role in cell adhesion and growth.The inspiration for the design and construction of micro-nano structures of materials is extensively borrowed from nature.Over millions years of evolution,living organisms have created an amazing variety of nano-micro multiscale structures to brings the organism special functions and features.Therefore,it has an important scientific significance to construct special biomimetic micro-nano structure on the biomaterial substrate.In the present work,combined with anodizing,molecular self-assembly and photochemical constituency degradation technology,we used metal titanium as the substrate and successfully prepared a superhydrophilic/superhydrophobic micropatterned template.Based on the views of bionics,we focused on the development ofelectrochemical deposition technique to construct uniform nano-micron structured octacalcium phosphate/silk fibroin(OCP/SF)composite coating and porous OCP coating,and exploration of the possibility to design the coatings for achieving the controllable preparation of surface chemical composition and micro-structure.In addition,the effects of the surface composition,structure,and spatial arrangement on leading and controlling the cell growth behavior were studied by using in vitro cell culture experiment,thus achieving cell micropatterning to supply a powerful technology platform for cell biology.The main results of this dissertation are outlined as follows:(1)The micropatterned superhydrophilic-superhydrophobic template was constructed on the surface of titanium metal by using anodizing technique,molecular self-assembly technique and photochemical constituency degradation technique.The size,shape,and spatial arrangement of superhydrophilic-superhydrophobic micropatterns can be controlled by using photomask plate.The physicochemical properties and the formation mechanism of template were studied.(2)Based on superhydrophilic-superhydrophobic micropatterned template,an electrochemical deposition technique was developed to successfully construct a novel nano-micron multiscale structured OCP/SF micropatterned composite coating and single scale porous OCP micropatterned coating.The size of OCP/SF and OCP micropatterns can be controlled precisely by tuning the size of superhydrophilic-superhydrophobic micropattern template.The results indicate that the OCP crystal size in the composite coating is significantly decreased from 200 nm to 25 nm by adding silk fibroin.In addition,the influences of some key preparing parameters on the structure and composition of the micropatterned coatings were systematically investigated.(3)In vitro cell culture test was used to evaluate the effects of OCP/SF composite micropatterned coating and OCP micropatterned coating on leading and controlling the cell growth behavior.The results indicate that the electrochemically prepared OCP/SF and OCP micropatterned coating could effectively lead and control cells to grow on designated microdomain for cell micropatterning formation.OCP/SF coating exhibits an excellent cell attachment and growth in the cell culture test,arising from its unique multiscale structure and appropriate chemical composition.Obviously,the electrochemically constructed OCP/SF composite micropatterns with nano-micron porous structure exhibits a markedly improved biological performance.