Study On Electrospun PLGA/Chitosan Composite Membranes For Artificial Skin

Electrospinning is a novel processing method that can produce ultrafine fibers with diameters ranging from 5 nm to 1μm. With high specific surface area and high porosity, scaffolds composed of electrospun fibers can provide a barrier to bacteria for wound when used as a skin substitute. Moreover, electrospun membranes feature a structural similarity to the natural extracellular matrix (ECMs). Therefore, they can mimick the nanoscale dimension of ECMs to provide cells with environmental signals and to promote cell adhesion and proliferation.In this study, fibrous membranes of chitosan (CS), poly(L-lactic-co-glycolic acid) (PLGA), hybrid PLGA/CS (H-PLGA/CS) and core/shell PLGA/CS (C-PLGA/CS) were produced by electrospinning, coelectrospinning and coaxial electrospinning, respectively. The morphology of ultrafine fibers were investigated by scanning electron microscope (SEM) and transmission electron microscope (TEM). The content of each component in membranes was measured by X-ray photoelectron spectroscopy and also by weighing after dissolving one component in the membranes. The results indicated that the H-PLGA/CS and C-PLGA/CS membranes contained about 40% and 10% of PLGA component, respectively. The H-PLGA/CS and C-PLGA/CS membranes showed relatively larger absorption in phosphate buffer solution (PBS)( 356.8%% and 454.8%,respectively) than that of PLGA(75.8%) due to introduction of the CS component. The mechanical properties of electrospun membranes were evaluated by tensile test, and the results indicated that the H-PLGA/CS and C-PLGA/CS membranes showed good tensile properties. Each membranes showed worse tensile properties when test in wet state than that in dry state.Fibrous membranes containing bovine serum albumin (BSA), ie, PLGA(BSA), H-PLGA(BSA)/CS and C-PLGA(BSA)/CS were produced by emulsion electrospinning, coelectrospinning and coaxial electrospinning. Results of SEM and TEM showed that the morphology of ultrafine fibers was related to the electrospun methods. The BSA loading efficiency of the PLGA(BSA) membrane was low (1.56%) and coelectrospinning and coaxial electrospinning could improve the BSA loading efficiency to 5.98% and 4.80%, respectively. At the early stage of BSA released from each membrane, the burst release was obviously observed. After 7 d, the drug release behaviors were nearly zero-order kinetics and after 28 d, the final release percentage for above three membranes were nearly 63%,88% and 94%, respectively. The electrospun membranes can retain fibrous morphology while releasing BSA.Studies on cell adhesion, proliferation and morphology on the fibrous membranes showed that the H-PLGA/CS membranes could mimic the structure of ECMs and positively promote cell-cell and cell-matrix interactions because the introduction of CS component improved the hydrophilicity and charge balance. The behavior of cells on C-PLGA/CS membranes was similar to that on CS membranes. Results of the in vivo wound healing study on rats back showed that CS, PLGA and H-PLGA/CS membranes obviously enhanced wound healing compared with the control. The result indicated that the electrospun nanofibrous membrane provided a good means for wound healing.