Abstract:

BACKGROUND: Crosslinked polymer chains have a remarkable effect on the fundamental properties and cytocompatibility of hydrogels, and crosslinking density can significantly change the formation of polymer chains. There are few studies on the effect of the properties of hydrogels caused by crosslinking density.

OBJECTIVE: To prepare a composite hydrogel with a favorable cytocompatibility and to explore the effect of crosslinking density on the properties of the hydrogel.

METHODS: Gelatin methacrylate solution was prepared, and decellularized meniscus extracellular matrix and LAP solution were added to prepare the pre-gel solution, which was crosslinked by blue ray. The crosslinking time was 10, 30 and 60 seconds. The compression elastic modulus, swelling ratio and degradability of hydrogels were detected. Meniscus fibrochondrocytes were added into the pre-gel solution, and crosslinked by blue ray. The cell viability, morphology and gathering were detected at 10, 30 and 60 seconds of crosslinking.

RESULTS AND CONCLUSION: (1) The hydrogel with 60 seconds of cross-linking time had higher compression elastic modulus than that of the hydrogel with 10 and 30 seconds of cross-linking time (P < 0.05). (2) The swelling ratio of the hydrogel with 10 seconds of cross-linking time was significantly higher than that of the hydrogel with 30 and 60 seconds of cross-linking time (P < 0.05). The swelling ratio of the hydrogels with 30 versus 60 seconds of cross-linking time had no significant difference (P > 0.05). (3) With the crosslinking time increasing, the degradation time of hydrogels increased. The hydrogels with 60 seconds of cross-linking time degraded completely at 80 minutes, and hydrogels with 10 seconds of cross-linking time degraded completely at 50 minutes. (4) After 24 hours of culture, the cell viability in all groups was over 95% (P > 0.05). (5) At 1 day after culture, the cells were in sphere-shape and distributed evenly in all groups. On day 4, the cells in all groups began to extend, and there were small cell masses in the hydrogels with 10 seconds of cross-linking time. On day 7, the dendritic extension in all groups was obvious, and there were dominant cell masses in the hydrogels with 10 seconds of cross-linking time. (6) After 1, 7 and 14 days of culture, cell viability in all groups was over 85%. At 1 day after culture, the cells in the hydrogels with 10 seconds of cross-linking time were in sphere-shape and distributed evenly. On day 28, the cells extended in dendritic shape, and gathered in reticular formation. (7) In summary, the property of gelatin methacrylate/decellularized meniscus extracellular matrix composite hydrogel can be optimized by adjusting crosslinking density.

Key words: hydrogel, gelatin methacrylate, decellularized extracellular matrix, property, crosslinking density, cytobiocompatibility, photo-crosslinking, meniscus