The Preparation And Application Of Electrospininig Fibers Based On Microfluidic Chip

In the 21st century, with ever-changing science and technology, the rapid development of information, energy, biology, environment and other fields has put forward higher demand for related materials. Especially, the researches on micro-nano-scale materials have become hot in many fields. Due to its small size, the micro-nano materials have special physical and chemical properties that distinguish conventional ones. Nanofibers are an important branch of nanomaterials and they have received more and more attentions because of their good mechanical properties, excellent conduction effect and high specific surface area.Electrospinning technology is a simple and easy method for preparing continuous micro-nano polymer fibers. Through the adjustment of fabricating parameters, various kinds of fibers with different structure can be obtained, and their potential applications can be found in many different fields. The microfluidic technology is an emerging subject which can produce a variety of micro-scale structures by manipulating the tiny fluids. Continuous uniform fibers prepared by microfluidic spinning have been applied in the field of tissue engineering and drug delivery system.Based on the previous researches of our group,this study have optimized the method of combining microfluidics and electrospinning to prepare bamboo-like fibers. The changes about porosity and water absorption of bamboo-like fibers are investigated, and we verify the potential application of cavities inside fibers in transporting plasmids. Then we add doxorubicin and apatinib to different parts of the fibers and investigate its therapeutic effect on drug-resistant tumors.In chapter 2, we investigate the structures of the bamboo-like fiber mats and achieved some potential applications with these fiber mats. The results show that the porosity of the membrane is higher than the conventional electrospun PLA fiber mats. In addition its water absorption efficiency is nearly as twice as the ordinary one. The reason may be that there are many cavities which containing glycerol in the bamboo-like fibers and glycerol has strong affinity with water. Based on this unique structure, we loaded the plasmids which can transcript green fluorescent protein into the cavities within fibers, which can well maintain the activity of the plasmids, as verified by cell experiments.In Chapter 3, fibers containing two kinds of drugs were prepared and characterized.The release curves of the fiber mats is investigated and we infer its mechanism by a series of characterization results, namely, with the degradation and breakdown of the cavity's thin wall , the drug and drug-loaded micelles will be released rapidly. However, the other drug embedded in the fiber matrix can only be released slowly. After that, I examine the effect of the fiber mats in inhibiting drug-resistant tumor cells in vitro, the results of which proved that the material have successfully reverse the drug resistance of tumor cells and achieved the goal to kill tumor cells.Based on the work in previous chapter, the in vivo anti-tumor study of drug-loaded fiber mats is carried out in Chapter 4. Firstly, we establish tumor model in nude mice's subcutaneously and then different fibers were implanted subcutaneously near the tumors. The drug distribution in mice and extracorporeal tissues is detected at different times,whose results proved that the drug-loaded fiber mats can promote the accumulation of doxorubicin in the tumor tissues significantly.