Study On The Controllable Preparation And Biological Performance Of The Micropatterned Polystyrene Microspheres And Highly Ordered Silk Fibroin Porous Films Based On The Superhydrophilic-superhydrophobic Template

Cell micropatterning is a technique that firstly uses the micro processing technology to prepare micropatterned cell growth substrate,and then induces cell to adhere on the specific spatial position by selective mechanism of authigenic adhesion.Cell micropatterning technology has been widely used in the field of biology,and has broad application prospects in the fields of biosensors,stem cell differentiation and drug screening.The common techniques of cell micropatterning include lithography,soft lithography and inkjet printing.However,most of these techniques require expensive equipments,complicated operations and harsh conditions,and the most widely used substrates are silicon,gold or glass.How to fabricate a larger area of cell micropatterns in biocompatible substrate in an easier and faster manner is the important development trend of cell micropatterning.In this dissertation,we constructed a superhydrophilic-superhydrophobic template based on metal titanium substrate and then successfully prepared high-ordered micropatterened polystyrene?PS?microspheres on the TiO₂ nanotube substrates with different sizes developed with molecular self-assembly technology.The influence of surface wettability,morphology and size of the micropatterned PS microspheres on cell morphology was also investigated.On the other hand,the micropatterned PS microspheres were used as template to fabricate micropatterned silk fibroin inverse opal structure.Qualitative and quantitative analysis of bovine serum albumin?BSA?adsorption in micropatterned silk fibroin porous film surface were also analyzed.The main results are as follows:?1?By PTES self-assembling and UV partition degradation technologies,we obtained the micropatterned superhydrophobic-superhydrophobic TiO₂ nanotube substrate.By vertical deposition method,monodisperse 1?m PS microspheres self-assembled into striped pattern on the template with wettability contrast.Pattern size of the micropatterned PS microspheres was the same as the template size.PS microspheres self-assembled in superhydrophilic regions and formed close packed colloidal crystal.The research showed that the pattern size of the micropatterned PS microspheres can be controlled accurately by controlling the size of superhydrophilic-superhydrophobic template.?2?The results of in vitro cell culture experiments indicated that after irradiating the micropatterned PS microsphere array with UV light,due to surface wettability contrast and PS microspheres used as physical barrier with certain height,can effectively guide the cells to grow with strip pattern.Cells selectivity adhered on superhydrophilic nanotubes surface,and the size of cell pattern was almost the same as substrate size.Cell pattern can maintained for 7 days.The pattern size of PS microspheres array played an important role in the regulation of cell migration and adhesion behavior.When cells were cultured for 7days,the filopodia of cells could easily migrate across the PS microspheres,and the cell striped pattern became unclear with gradual decrease of the pattern size.When the pattern size was small enough,the growth state of single cell would be affected and changed.When the pattern size was reduced to 50?m/100?m,cells cultured for 1 day on the samples with wettability contrast,showed significant cell elongation along the direction of pattern.The cell angle and stripe pattern was in parallel.Cell shape showed anisotropy specific.?3?Using the micropatterned PS microspheres as template,silk fibroin solution was then poured into the template,and finally we got the micropatterned silk fibroin porous films.The porous films were highly ordered and interconnected in structure.Qualitative research of protein adsorption showed that the silk fibroin films were beneficial to improve the adsorption capacity of the protein because of the highly ordered and interconnected porous structure and significantly increased specific surface area.FITC-BSA selectively adsorbed on the porous silk fibroin films and formed strip micropattern.When FITC-BSA adsorbed for 12 h,the pattern of protein was the best.The quantitative study of protein adsorption showed that the concentration of BSA decreased with the increase of adsorption time.BSA quickly adsorbed on the porous silk fibroin films,and then the adsorption was slow,indicating that the adsorption amount tended to saturation.