Preparation And Characterization Of Electrospun Tetracycline Hydrochloride-loaded Chitosan/poly(Lactic Acid) Nanohberous Membrane

Drug sustained release systems are gaining increasing attention because oftheir extended therapeutic efficacy, safety of drugs and reduced adverseeffects. In this study, Tetracycline hydrochloride (Tet) is choosed as modeldrug. Casting and Electrospinning are taken to fabricate CS/Tet films andCS/PLA/Tet films with varied Tet contents.Casting is a straightforwardmethod to produce flat polymer films in controlled drug delivery.Electrospinning is a nanofiber-forming technique by which either polymersolution or melt is charged to high voltages, with diameters in the nanometerrange which is widely used in functional fibers. Chitosan (CS) has enhancedbiocompatibility, biodegradability and bacteriostasis. For its poor initialstrength and fabrication ability which can not meet the need, chitosan iscomposited with poly(lactic acid)(PLA) which has been used widely in theclinic.The main results are as follows:(1) The result of the drug release in vivo shows that Tet entrapmentefficiencies were well above60%for all the CS/Tet films and the entrapmentefficiencies is in inverse proportion with the weight of Tet which is inproportion with burst effect. The CS/Tet films have the strong bacteriostasisfunction to golden brown staphylococcus. Along with the increase of the Tet,antibacterial effect is better. Until the10%Tet loaded films, the antibacterialeffect did not change significantly. The rate of degradation for CS/Tet filmswas faster than pure CS film. Both the flims with Tet loading of10%and20%could be degraded completely within8days. Comparatively speaking, castfilms with Tet loading of10%is good choices considering the price andcurative effect for the prevention of bacterial infections in guided tissueregeneration.(2) A uniform electrospun solution of CS and PLA mixture was obtained byblending CS formic acid solution and PLA chloroform/ethanol solution, andthen CS/PLA composite nanofibers were prepared from the as-preparedelectrospun solution by eletrospinning technique. The morphology and structure of the nanofibers were investigated by scanning electron microscopy(SEM), Fourier transform infrared (FT-IR). The results show that CS/PLAcomposite nanofibers sized290±28nm in diameter could be fabricated underthe optimized conditions as following: volume ratio of CS formic acid solution(concentration of CS is1.6%by weight) to PLA chloroform/ethanol solution(concentration of PLA is15%by weight, volume ratio of chloroform toethanol is1:1) is1:1, voltage is15kV, and tip-to-collector distance (TCD) is15cm. Moreover, there exist hydrogen bonds between CS and PLA molecularin the CS/PLA fibers matrix.(3)The CS/PLA/Tet blend fiber were electrospun from a blend formic acidcontainning chitosan(CS) and Tet and chloroform/ethanol solutionscontainning poly(lactic acid)(PLA). The morphological characters of thenanofiber with different Tet contents were not chanced which were observedthrough the scanning electron microscopy. The release of the tetracyclinehydrochloride from these fiber mats was followed by UV-VIS spectroscopy.Tet entrapment efficiencies are well above70%for all the CS/PLA/Tet filmswhich is increased obviously than CS/PLA films. With increasing of Tet,entrapment efficiencies are gradually decreased while burst release is moreserious. In vitro antimicrobial activities were tested from modifiedKirby-Bauer test. CS/PLA/Tet films are effective in inhibiting growth ofstaphylococcus aureus, whose effect are increased with the increase in thecontent of Tet until the content is0.2g/g. Degradability of CS/PLA/Tet filmsin vitro shows that Tet can promote films degradation obviously. When thecontent is0.2g/g, degradation of the film can be finished after16days. Soconclusion is that CS/PLA/Tet nanofibrous films with Tet loading of10%isgood choices considering the price and curative effect for the prevention ofbacterial infections in guided tissue regeneration.