Abstract:

Objective To discuss the effect of hydrogel-based delivery of basic fibroblast growth factor （bFGF） on the function of the NIH3T3 fibroblast cells after oxygen-glucose deprivation （OGD），and to clarify the improvement effect of bFGF-loaded hydrogel on the oxidative stress responses in the fibroblasts under the OGD condition. Methods The bFGF-containing agarose hydrogel was prepared， and the NIH3T3 cells at logarithmic growth phase were divided into blank group， 20% agarose group， and 20% agarose + glutaraldehyde group. The viabilities of the NIH3T3 cells after co-cultured with the hydrogel-eluted fluid for 6， 12， and 24 h were detected by CCK-8 assay. The NIH3T3 cells were divided into control group， OGD group， and OGD + different masses of bFGF-loaded groups （OGD + 1 ng bFGF group， OGD+10 ng bFGF group， and OGD+100 ng bFGF group）. The expression levels of α-smooth muscle actin （α-SMA）， type Ⅰ collagen， and type Ⅲ collagen proteins in the NIH3T3 cells in various groups were detected by Western blotting method； the content of malondialdehyde （MDA） and activities of lactate dehydrogenase （LDH） and superoxide dismutase （SOD） in the NIH3T3 cells were detected by assay kits； the in vitro release rate of bFGF in the NIH3T3 cells in various groups was detected by enzyme-linked immunosorbent assay （ELISA） method. Results The CCK-8 assay results showed that compared with blank group， the viability of the NIH3T3 cells between blank group， 20% agarose group， and 20% agarose+ glutaraldehyde group at different elution times had no significant difference（P>0.05）. The Western blotting results showed that the expression levels of α-SMA and type Ⅰ collagen proteins in the NIH3T3 cells in OGD group were significantly higher than that in control group （P<0.05 or P<0.01）.Compared with OGD group，the expression levels of α-SMA and type Ⅰ collagen proteins in the NIH3T3 cells in OGD+1 ng bFGF， OGD+10 ng bFGF， and OGD+100 ng bFGF groups were significantly decreased （P<0.05 or P<0.01） in a dose-dependent manner.Compared with control group，the level of MDA and activity of LDH in the NIH3T3 cells in OGD group were increased（P<0.05）， while the activity of SOD was decreased （P<0.05）. Compared with OGD group， the level of MDA and the activity of LDH in the NIH3T3 cells in OGD + 1 ng bFGF group were decreased （P<0.05）， while the activity of SOD was increased （P<0.05）.The ELISA results showed that about 10% bFGF was released from the hydrogel within 4 h， about 15% bFGF was relleased from the bydrogel with in 12 h， and about 21% bFGF was released from the hydrogel within 24 h. Conclusion The bFGF-loaded hydrogel can modulate the transformation of the fibroblasts under the OGD condition，inhibit the expression of typeⅠ collagen protein，and improve the oxidative stress responses in the fibroblasts. Moreover，this system exhibits a sustained drug-release ability.

Key words: Hydrogel, Basic fibroblast growth factor, NIH3T3 cells, Collagen, Oxidative stress