Enzymatically-gellable pectin-gelatin hydrogels for tissue engineering applications: hydrogel characteristics, chondrocyte cell behaviour and subcutaneous implantation

Pectin as an economical polysaccharide source has attracted increasing attentions for tissue engineering application. Due to the lack of adhesion motifs in polysaccharides, in this work, gelatin was added to pectin and enzymatically-gellable pectin-gelatin derivative both possessing phenolic hydroxyl (Ph) groups was synthesized and characterized for use in tissue engineering applications. Concentrations of pectin and gelatin were both 1%. The mixture was modified by tyramine hydrocholoride in the presence of EDC/NHS for 1 day at 25°C. The derivative (Pec-Gel-Ph) was characterized by UV, FTIR, gelation time, enzymatic degradation, mechanical and swelling properties as well as water vapor loss at different horse radish peroxidase (HRP) and H2O2 concentrations. Chondrocyte at X0 = 2×106 cells/ml gel was cultured as an adherent model stem cell for 14 days and MTT assay was used for cell activity measurements. Direct subcutaneous implantation of the cell-laden hydrogels as well as the hydrogels without cells was carried out in rats and H & E staining was performed after 1 month. Pec-Gel-Ph showed a peak in 275 nm in UV test and in the interval of 987-1464 cm-1 in FTIR which is the sign of fixation of phenol groups. The concentrations of Pec-Gel-Ph and HRP had more impact on the gel formation time. Pec-Gel-Ph hydrogels showed lower mechanical strength, higher swelling and degradation properties, higher water vapor loss as compared to Pec-Ph hydrogels. Chondrocyte cells cultured in Pec-Gel-Ph hydrogels could proliferate more than two times higher than the cells cultured in Pec-Ph hydrogels during the culture period. The subcutaneous hydrogels could be identified readily without complete absorption and signs of toxicity or any untoward reactions after 1 month. Viable chondrocyte cells were seen as red colored areas in the cell-laden hydrogels. The study demonstrates the potential of Pec-Gel-Ph hydrogels for tissue engineering applications.

کلیدواژه ها:

Pectin ، Gelatin ، Hydrogels ، Tissue engineering ، Enzymatically-gellable ، Cell culture