Fabrication Of Micro-and Nano-structures Via Super-phobic Micro-pillar Arrays

Micro-pillar arrays are widely applied for wettability control and patterning material preparation owing to the special size,high aspect ratio and arrayed arrangement.After chemical modification,unique wetting properties can be imparted to micro-pillar arrays.Biomolecular materials,such as polysaccharides and polyesters with high biocompatibility and high degradation ability,are being developed as nanoparticle carrier,cell scaffold,etc.Herein,we have demonstrated two new strategies for preparing micro-nano structures of biomaterials based on micro-pillar arrays.1.First part demonstrates a new strategy to adhere micro-droplets on the top of micro-pillars and prepare uniform-sized spec ial-structured particles via liquid bridges generation and fracture during the movement of droplets on super-phobicity,high-adhesion micro-pillar structured substrate.Polysaccharide micro-hydrogels(PsMH)were prepared via adhering polysaccharide prepolymer solution on micro-pillars and cured with ultraviolet light during volatilization.The results showed that with uniform size and evenly distribution,PsMH can be effectively adjusted by altering the concentration of polysaccharide prepolymer solution and the diameter of micro-pillars.Red fluorescent PsMH were introduced after attaching quantum dots to the polysaccharide prepolymer solution.Guiding with similar ideas,polyester solution was adhered to micro-pillars in water environment,and Janus spiky polyester micro-particles(JSPMP)were fabricated via solvent evaporation self-assembly.The study found that by changing the concentration of polyester solution and the molecular weight,the particle size and morphology of JSPMP can be adjusted.The biomaterial microparticles demonstrated via this strategy highlighted the application of drug delivery,nanoparticle carriers,and precise single cell drug delivery.2.Combining superhydrophobic micro-pillar array and solvent evaporation self-assembly,micro-nano structure chip(MNSC)has been fabricated to isolate circulating tumor cells(CTC)after modification of immune antibody.CTC shedding from solid tumors and entering the blood circulation,is closely associated to tumor metastasis and initiation,with great value to guide tumor diagnosis,prevention and targeted therapies.Results have shown that by changing the volume and molecular weight of the polyester in the oil solution,the morphology and coverage of the nanostructures can be precisely controlled.After modified with anti-EpCAM antibody,the MNSC can capture epithelial carcinomas efficiently and selectively while maintaining the physiological activity of cancer cells,which is convenient for subsequent analysis.The MNSC prepared by this method has potential application in CTC capture,liquid biopsy and other aspects.In aforementioned two strategies,we have integrated the micro-pillar array with the advantages of biomolecular,utilizing the fabrication of PsMH,JSPMP and MNSC.The potential of special structure micro-nano devices has been highlighted in nanoparticle carrier and tumor detection by physicochemical and biological experiments.The data obtained in the above two research will provide effective information for the next application of biomaterials combined with micro-pillar arrays.