载外泌体银纳米颗粒抗菌水凝胶的构建及其对人表皮HaCaT细胞增殖的影响OA北大核心CSTPCD

Objective:To construct the antibacterial hydrogel containing mesenchymal stem cell exosomes(MSC-Exo)and silver nanoparticles(AgNPs),and to preliminarily clarify its antibacterial activity and proliferative effect on the human epidermal HaCaT cells,and to clarify its application potential in treatment of skin wound.Methods:The basic hydrogel scaffold was fabricated using oxidized dextran(ODex)and modified hyaluronic acid(HA-ADH).The AgNPs were synthesized with cetyltrimethylammonium bromide(CTAB)as the stabilizer,while the MSC-Exo was isolated from the cultured mesenchymal stem cells(MSC).The AgNP/HA-ADH/ODex hydrogel and MSC-Exo@AgNP/HA-ADH/ODex hydrogel were constructed.The loading rate of the Msc-Exo was evaluated through BCA assay;dynamic light scattering(DLS),Zeta potential measurement,and ultraviolet-visible spectroscope were used to analyze the morphology,the charged status of the AgNPs;fourier transform infrared spectra was used to detect the compositions of the HA-ADH/ODex hydrogel framework;transmission electron microscope(TEM),nanoparticle tracking analysis,and Western blotting methods were used to identify the presence of MSC-Exo;the cell survival rates of the HA-ADH/ODex hydrogel and the AgNP/HA-ADH/ODex hydrogel,and the effect of MSC-Exo@AgNP/HA-ADH/ODex hydrogel on the proliferation rate of HaCaT cells were detected by CCK-8 assay;the antibacterial efficacy of the AgNP/HA-ADH/ODex hydrogel was detected by spread plate method and turbidity measurement.Results:The DLS,Zeta potential,and ultraviolet-visible spectrum results showed the successful synthesis of uniform and positively charged AgNPs.The fourier transform infrared spectrometry results showed the HA-ADH/ODex hydrogel was properly formulated.The identification of MSC-Exo was verified by TEM,nanoparticle tracking,and Western blotting methods.The BCA assay results showed that the loading rate of the MSC-Exo on the MSC-Exo@AgNP/HA-ADH/ODex hydrogel was 77.8%.The CCK-8 assay results showed that the survival rates of the HaCaT cells were close to 100%when treated with the dilution ratios of 0,1,2,4,8,16,32,and 64 of culture medium-extract of HA-ADH/ODex hydrogel.For the AgNP/HA-ADH/ODex hydrogel extracted with dilution ratio of 8 and above,the survival rates were greater than 85%.The spread plate method results showed that the antibe terial rates of AgNP/HA-ADH/ODex and MSC-Exo@AgNP/HA-ADH/ODex hydrogels against Staphylococcus aureus(S.aureus)and Escherichia coli(E.coli),and the antibacterial rates against S.aureus and E.coli were(96.44±0.16)%,(96.62±0.16)%and(95.73±0.28)%,(95.58±0.14)%,respectively.The CCK-8 assay results showed that the MSC-Exo@AgNP/HA-ADH/ODex hydrogel promoted the proliferation of the HaCaT cells,and the proliferation rate was(115.00±7.42)%.Conclusion:The MSC-Exo@AgNP/HA-ADH/ODex hydrogel exhibits the excellent antibacterial properties and good ability to promote the proliferation of human epidermal HaCaT cells;it is a safe and effective bio-dressing for the treatment of skin wounds.