Preparation And Investigation Of Highly Aligned Drug-fiber Matrix Blends

Nano-and micro-meter scale fiber structure with one-dimensional direction distribution,have been widely used in textile,energy,environment and biomedical engineering.However,as the most frequently used method to fabricate fibers,electrospinning is unable to produce aligned fibers without extra collector device,and conventional electrospinning is yet unable to meet demands encountered on the industrial scale.Centrifugal electrospinning combines both centrifugal and electric field forces,which offers greater promotion on fiber alignment as well as the yielding rate.In this study,the development of enhanced spinneret devices was demonstrated,the matching devices and fabrication methods were also established after investigating the impact of experimental process on resulting fiber properties.In addition,the controlled fiber properties,such as drug release behavior,hydrophilicity and mechanical properties,were achieved on the basis of regulation ability from redesigned centrifugal electrospinning systems and corresponding fabrication methods.The centrifugal electrospinning system was firstly demonstrated,the spinneret device provides an enhanced approach for active embedded fiber production on a scale favorable to industry(120 g/h)when using four outlets and feeding inlet design.The influences between working parameters and fiber morphologies were investigated.Also,the patterning of multi-layered aligned fibers were initial implementated.In addition,fiber orientation and stacking provides a route to control drug release rate.Second,multiple compartments and a modified spinneret were presented.A combinatorial system for polystyrene(PS)and polyvinyl pyrrolidone(PVP)was exemplified and quantified.The relationship between two simultaneously jetting and eventually adjacently forming and aligned fibrous materials was explored.The system is applicable to almost any polymeric material,such as thermoplastic polyurethane(TPU),polycaprolactone(PCL).The present work demonstrates a promising low-cost and facile approach for large-scale production of stacked and blended fibers.After the design of dual rotation centrifugal system,one-to multi-demensional blend fiber(PVP and TPU)structures were gathered on the rotating collector.Four stages of centrifugal electrospinning process were determined,and the influences of air velocity and collector rotation speed to fiber morphologies were explored.The multi-dimensional fiber structure presents similar characteristics in different distributions through static water contact angle test and in vitro cultivation of fibroblast.The drug release test further confirmed that the regulation of drug release rate can be achieved by the composition of compound materials and the adjustment of structure.Three-phase centrifugal electrospinning system was finally established to fabricate blend fibers composed by pyrrolidone(PVP),thermoplastic polyurethane(TPU),poly-methyl methacrylate(PMMA).This system further expanded the number of containing materials in blend fibers.By controlling the composition of blend fiber,the fibrous membrane characteristics can be controlled,and the application values of composite fiber membrane is greatly expanded.This study accomplished the regulation of fiber membrane characteristics by redesigned centrifugal electrospinning system,and explored the influence of working parameters to the centrifugal electrospinning process,which provides the foundation for more complex centrifugal electrospinning system.