The Preparation Of CNCs/PLGA Nanofibres And Its Application In Wound Healing

Nowadays, the common methods of healing skin injury are wound dressings, autologous, allogeneic or artificial materials, etc. However, The risk of reinfection exists in the process of wound dressing. Autologous skin graft is the gold standard for the treatment of skin defect at present. Due to the limited source of autologous skin, the treatment of large area of skin defects in patients with inadequate skin area and the risk of multiple surgery greatly increased the cost of treatment and psychological pressure of patients,which limits its wide application. So it is urgent to solve the problem that the tissue engineering materials which are applied in the skin wound healing are: biocompatibility, rejection reaction, the stability of the material and the corresponding mechanical properties. Therefore, in order to achieve good skin wound healing effect of prepared a having a human skin bionic structure, a breathable moisture permeability, high porosity, nontoxicity, no strong row of abnormal reaction, there is conducive to cell adhesion growth and with certain mechanical strength of the scaffolds for tissue engineering are particularly critical.Poly(lactic-co-glycolic acid)(PLGA), due to its good biocompatibility and biodegradability, is widely used in the field of biomedicine, tissue engineering, etc. However, since it is hydrophobic, and its mechanical properties are not very well when prepared into nano fibers, which limit the application of PLGA in practice. In this study, nano microcrystalline cellulose(CNCs) with rod-shaped microstructure was prepared through concentrated sulfuric acid hydrolysis method, using microcrystalline cellulose(MCC) as raw material. The CNCs were added to the solution of PLGA at the mass ratio of 0%, 1%, 3%, 5% and 7% of PLGA, respectively. Then a series of CNCs/PLGA composite nanofibers by electrospinning was made by electrospinning. The analysis and physicochemical characterization were conducted. Results showed that the incorporation of CNCs did not significantly change the rod morphology of PLGA nanofiber, and thermal stability and dynamic mechanical properties of composite nanofiber were correspondingly increased, surface hydrophilicity was also promoted. In vitro experiments showed that CNCs had little cell toxicity and could promote the adhesion and proliferation of cells on fibrous membrane. In addition, among CNCs/PLGA composite nanofiber with different percentages of CNCs, 7wt% CNCs/PLGA showed the best mechanical properties, the ultimate tensile strength reached 21.28 ± 0.37 MPa, which can meet the corresponding mechanical requirements of skin wound repair materials in transplant operations.In order for the better use in wound healing, curcumin(Cur) and expression angiogenin(ANG) plasmid DNA p DNA-ANG were co-loaded to CNCs/PLGA composite nanofibers to prepare CNCs/PLGA/Cur/pDNA-ANG. Release of Cur and pDNA-ANG from composite nanofiber film was investigated, respectively. Furthermore, the model of rat full-thickness burn defect was established, and anti infection ability, wound healing ability, as well as the effect on promoting vascular regeneration of CNCs/PLGA/Cur/pDNA-ANG was evaluated. The results indicated that the new CNCs/PLGA/Cur/pDNA-ANG had certain effects on anti-infection and vascular regeneration, accelerated wound healing, and had potential application in the field of skin regeneration.