Study On Tissue Engineering Scaffolds With The Properties Of Anti-inflammation And Promoting Vascularization For Burned Skin Regeneration

Susceptibility to inflammation infection and difficulty in angiogenesis are two major obstacles in burned skin regeneration.In this thesis,anti-inflammatory tissue engineering scaffold loaded with functional gene was designed to solve these problems.Hyaluronic acid(HA),dextran(Dex)and β-cyclodextrin(β-CD)were vinylated with methacrylic acid anhydride(MA),N-hydroxy ethyl acrylamide(HEAA)and poly(ethylene glycol)methyl acrylate(526),respectively.Then,resveratrol(Res),anti-inflammatory factor,was encapsulated into the cavity of β-CD by hydrophobic interaction,and a loading ratio of 1:1(molar ratio of 526-β-CD to Res)could be achieved,which was confirmed by 1H-NMR spectroscopy,UV-vis spectroscopy,and differential scanning calorimetry(DSC).The hydrogels with different monomer proportions were obtained by crosslinking of HAMA,Dex-HEAA and 526-β-CD-Res under UV irradiation.After assessing equilibrium water content,porous morphology and mechanical strength of the hydrogels with different proportion,the hydrogel with MAHA(1%),Dex-HEAA(10%)and 526-β-CD-Res(1.2%)was finally optimized for the further characterization and subsequent animal experiments.Specifically,this hydrogel had an equilibrium water content of 88.2%,a pore diameter of 50-100 μm,and a compressive strength of 68 kPa.In order to promote angiogenesis,plasmid DNA encoded with vascular endothelial growth factor(pDNA-VEGF)was loaded into the scaffolds,which were then transplanted into the burned defects on SD rats.Hematoxylin and Eeosin(H&E)staining,masson staining,and immunohistochemistry staining were used to analyze the neo-tissues.The results showed that the scaffolds loaded with Res and gene had best restoration.To further confirm the results,real time polymerase chain reaction(PCR)technique was employed.The results showed Res could effectively suppress the generation of tumor necrosis factor(TNF-α)and interleukin 1β(IL-1β).Meanwhile,pDNA-VEGF loaded into the scaffolds was able to promote VEGF expression,and accelerated angiogenesis obviously.The results indicated the tissue engineering scaffold constructed with both anti-inflammation and promoting vascularization had an excellent regenerative effect for burn wounds.