Preparation And Properties Of Polyvinyl Alcohol/Silica Composite Fibers By Electrospinning

In recent years,silica(SiO2)fibers prepared by electrospinning have attracted a great deal of attention in the field of biomedical engineering because of their large specific surface area,good mechanical property and stability.It was found that,when used as a bone repair material and implanted into the body,SiO2 xerogel can promote the aggregation of a large number of free phosphate ions and calcium ions in body fluids.As a result,the bone-like apatite can be generated to accelerate the efficient healing and recovery of bone injury sites.Besides,polyvinyl alcohol(PVA)have been widely applied in the biomedical field ascribing to its good biocompatibility and biodegradability.From the perspective of synergistic enhancement,the combination of SiO2 xerogel and PVA could be a promising strategy to obtain the high-performance bio-fiber materials.In this paper,the PVA/SiO2 composite fibers were fabricated via a combination of in-situ synthesis and electrospinning.Specially,the effects of various experimental parameters on the preparation of composite fibers were investigated,and the optimal preparation scheme has been achieved.The biological activity and drug release behavior of the PVA/SiO2 composite fiber were preliminarily characterized.Moreover,the further preparation for obtaining PCL@PVA/SiO2 coaxial composite fiber was also investigated.And the related characterizations were illustrated in detail.The main results of this paper are listed as follow:(1)Preparation of PVA/SiO2 composite fiber with a theoretical silica content of 20%was realized via a uniaxial electrospinning method.The obtained composite fiber exhibits the uniform morphology and an average diameter of 258.6 nm,without obvious structural defect.Silica is present in an amorphous phase,and evenly mixed with polyvinyl alcohol.The corresponding silica content is 19.7%,which is consistent with the theoretical value.Besides,the investigation of composite fiber in a 1.5SBF solution proves the excellent biological activity of composite fiber.In a word,PVA/Si02 composite fiber could be a promising candidate in the field of bone tissue engineering.(2)Tetracycline hydrochloride was used as a model drug to evaluate the drug release properties of PVA/SiO2 composite fiber.The results show that cumulative drug release rates of pure PVA fiber,PVA-10%SiO2 fiber,PVA-20%SiO2 fiber and PVA-30%SiO2 fiber winin 6 h of release time are 53.8%,59.1%,62.5%,and 61.6%,respectively.It can be found by comparison that the introduction of SiO2 was effectively improved the cumulative drug release rate of the PVA fiber.(3)The coaxial composite fiber with a shell layer of PVA/SiO2 and core layer of PCL was fabricated via coaxial electrospinning.The obtained composite fibers possess a uniform morphology,an average diameter of 264.2nm and the narrow distribution of fiber diameter.Besides,the fiber exhibits the good mechanical properties and biological activity.(4)Tetracycline hydrochloride was employed to evaluate the drug release performance of PCL@PVA/SiO2 coaxial composite fiber.The results show that the release time and cumulative drug release rate of pure PCL fiber and PCL@PVA-20%SiO2 coaxial composite fiber were 1 h and 68.7%,2 h and 40%,respectively.Compared with pure PCL,the coaxial composite fiber has a more sustained release effect.However,the further improvement of drug release ability of the coaxial composite fiber is still required.