ساخت و ارزيابي داربست هيدروژلي بر پايه كيتوسان/ پلي‌وينيل الكل/ نانوذرات اكسيد روي، حاوي آلانتوئين براي درمان زخمهاي سوختگي

Fabrication and eva‎luation of a hydrogel scaffold based on chitosan/ polyvinyl alcohol/ zinc oxide nanoparticles, containing allantoin for burn wound healing

مهندسي پزشكي

The damages caused by burns often lead to extensive tissue injury, prolonged healing times, and increased risk of infection. Tissue engineering of the skin has emerged as a promising approach to address these challenges. The aim of this research was to fabricate and eva‎luate hydrogel scaffolds based on chitosan-polyvinyl alcohol-zinc oxide nanoparticles-allantoin (CS-PVA-nZnO-Allan) for skin tissue engineering. To achieve this goal, green synthesis of zinc oxide nanoparticles was initially performed using pomegranate peel extract. The synthesized zinc oxide nanoparticles were eva‎luated using X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR), demonstrating their crystalline structure and high purity. Field-emission scanning electron microscopy (FE-SEM) results showed predominantly spherical nanoparticles with sizes ranging from 22 to 26 nanometers. Subsequently, hydrogel scaffolds were fabricated using a bioprinter, with the following compositions: chitosan-polyvinyl alcohol-allantoin (CS-PVA-Allan), chitosan-polyvinyl alcohol-zinc oxide nanoparticles (CS-PVA-nZnO), and chitosan-polyvinyl alcohol-zinc oxide nanoparticles-allantoin (CS-PVA-nZnO-Allan). The structure and chemical composition of these scaffolds were eva‎luated using FE-SEM and FTIR, confirming their porous nature (approximately 404-426 microns) and chemical composition consistent with the raw materials used. Mechanical property testing indicated that the CS-PVA-nZnO-Allan hydrogel scaffold had an elastic modulus of approximately 11.70 MPa, which is beneficial for skin tissue engineering. T. The Darbast CS-PVA-nZnO-Allan exhibited desirable hydrophilicity with a contact angle of approximately 40.13 degrees, a swelling percentage of about 450-600 percent, and a water vapor transmission rate of around 2000 (g/m²h), indicating that it is beneficial for wound healing applications. Additionally, the degradation rate over 28 days was approximately 35%, with pH changes observed between 7.25 and 7.45. Release studies showed an initial burst release of allantoin up to 60% within 24 hours, followed by sustained release up to 92% over 192 hours. The CS-PVA-nZnO-Allan scaffolds exhibited significant antibacterial activity against Staphylococcus aureus and E. coli bacteria, with colony counts as low as 3106 and 5106, respectively, among tested samples. Cell viability assays (MTT) demonstrated that the CS-PVA-nZnO-Allan hydrogel scaffold supported approximately 111% cell viability over seven days, indicating non-toxicity and potential for promoting cell growth and proliferation. Moreover, it exhibited the highest fibroblast cell adhesion compared to other samples. Based on these findings, the CS-PVA-nZnO-Allan hydrogel scaffolds can be considered a promising candidate for skin tissue engineering applications

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