Because of the inherent appearance similar to the natural extracellular matrix,ultrafine fibrous membranes prepared via electrospinning exhibit widespread applications,especially in the biomedical area.Extensional modifications of coaxial and emulsion electrospinning have drawn much attention in preparation of core/shell fibers for applications as tissue engineering scaffolds and controlled delivery systems for bioactive substances.Due to incorporation of multi-components in the electrospun core/ shell fibers,the process of coaxial and emulsion electrospinning became more susceptible.The theories have not been fully understood.A series of investigations were carried out evaluating the systematic and processing parameters.This paper reviews advantages and potentials of electrospun core/shell fibers as well as factors influencing their formation on the basis of our research and new progress.
ZHANG Hong,ZHAO ChenGuang,ZHAO YunHui,TANG GongWen & YUAN XiaoYan School of Materials Science and Engineering,and Tianjin Key Laboratory of Composite and Functional Materials,Tianjin University,Tianjin 300072,China
In order to encapsulate and controlled-release bioactive proteins,three fibrous membranes,i.e.,poly（L-lactide-co-glycolide）（PLGA）,hybrid PLGA and chitosan（H-PLGA/CS）,and core/shell PLGA/CS （C-PLGA/CS）,were produced by emulsion electrospinning,co-electrospinning and coaxial electrospinning,respectively.Bovine serum albumin（BSA） was selected as a model protein.The loading efficiency of BSA in the PLGA membrane was 1.56%,lower than those of H-PLGA/CS（5.98%） and C-PLGA/CS（4.80%）.BSA release profiles from the three membranes showed initial burst releases in the first 7 d and then sustained release for 28 d.Cumulative releases at the end of the releasing period,28 d,from the above three membranes were nearly 63%,88% and 94%,respectively,indicating that the introduction of chitosan and the core/shell fiber structure could enhance BSA release rate.In addition,all these electrospun membranes could retain their fibrous morphologies after in vitro release of BSA for 28 d.
