Preparation Nanofibers From Polyester Of Lactic Acid Type And Their Drug Release Profiles

Nanofiber made of polymer has a high specific relative surface area, good mechanical properties, which are widely used in drug controlled and targeted release, tissue engineering, implant surface modification, etc. Electrostatic spinning technology is the only method for preparing nanoscale fibers continuously. The equipment of electrospinning is simple and can be operated easily. The nanofiber from electrospinning is potentially uesed as carrier for drug release, photoelectric device, sensor technology, catalytic, filtration, biological and medical tissue engineering. In the field of medicine, the biocompatibility, biodegradable, nontoxic polymer arised as required. For that reason, a large number of researches focused on synthetic polymer polyester, using in tissue engineering and drug release. There are so many properties on polyester, such as mechanical performance, hydrophobic, biocompatibility, biodegradation and non-toxic, etc. So it is widely used as carrier in tissue engineering and drug release. This paper comparely studied three kinds of lactic acid type polyester (ABP) nanofibers made by electrospinning and their mechanism on drug release. The blended and coaxial-spun nanofibers with the hydrophilic material (polyvinyl pyrrolidone, PVP) were prepared by contrast. Then the influenced factors on static electricity spinning process were studied and the suitable spinning conditions were got.Captopril (CPL) was used as a drug model, whose maximum absorption peak through ultraviolet wavelengths when drug was released. The molecule of CPL with short half-life was rapidly lysis which was bad to the gastrointestinal tract, which is a limit on clinical application. In order to improve the drug bioavailability, reducing its side-effects and prolonging drug effect is needed. In this paper, the nanofiers of Polylactic acid (PLLA), Poly glycolic acid (PLGA) and Poly caprolactone (PLCL) was maded by single electrospinning. The best conditions of electrospinning were discussed, for Polylactic acid (PLLA), Poly glycolic acid (PLGA) and Poly caprolactone (PLCL), which were the solvent were all Methylene chloride/acetone (2:1v/v), quality volume concentration were8%,20%,20%(w/v); high voltage were15kV,12.5kV,14kV; the flow rate were0.8mL/h,1.5mL/h,1mL/h respectively; the ambient temperature was (25±1)℃, relative humidity (RH) was (60±5)%, the receivable distance was15cm. Nanofibers with Captopril were charactered by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), Differential Scanning Caborimetry)(DSC) and X-ray diffraction (XRD) measurements, which found that Captopril was in the form of amorphous state and hydrogen bonding interaction with carrier. There were any difference between PLLA, PLGA and PLCL.The effection hydrophilic carrier for nanofibers was discussed again. First, hydrophilic nanofibers were made by coxial el ctro spinning. Solvent was used as core, PVP for shell, we found a new way to refining nanofiber using coaxial electrospinning technology. Then, the blended nanofibers of polylactic acid (PLLA), poly glycolic acid (PLGA), poly caprolactone (PLCL) with polyvinyl pyrrolidone (PVP) loaded CPL, respectively was made by electrostpinning. And, nanofibers Polylactic acid (PLLA), Poly glycolic acid (PLGA), poly caprolactone (PLCL) was used as shell and polyvinyl pyrrolidone (PVP) as core was studied by coaxial electrospinning. Research shows that drug carrier swelling property is improved, and the water is good. From the load medicine nanometer fiber felt swelling and weightlessness behavior to see, gas swelling degree is not completely and drug release completely consistent. The swelling degree of PLLA is the largest, which looks like a sponge; PLGA is harden brittle; PLCL flexibility is good, the exterior also did not change significantly.In addition to the nature of the drug itself outside, release medium on the drug release of the impact is bigger also. The release medium pH, temperature and type on the release of drug effect is bigger, which will produce an release and fast to slow the overall trend is pH7.4>pH6.8>pH1.2and37>25℃, but not completely conform to, because the release of drugs and drug molecule carrier types and relevant. As the drug carrier release model speaking, release model type of the three kinds of lactic acid type polyester is Weibull model, that means drug inside with short time by diffusion release, long time is drug carrier of performance degradation.Through the electrostatic spinning preparing nanofibers loaded with medicine, we find that a release rule from lactic acid type polyester. And the successful on synthesis of ABP/PVP blended and ABP (PVP) core-shell nanofibers, wich was the foundation for the subsequently contrastive researches on drug release.