Study Of PLG-g-TA/RGD Enzyme-catalyzed Crosslinked Hydrogel For Adhesion And Three-dimensional Culture Of Hyaline Chondrocytes

Hydrogels are widely considered to be ideal scaffolds for three-dimensional cell culture due to their soft tissue-like properties and the ability to achieve uniform loading of cells.However,the hydrogel nano-scale pore size limits cell adhesion and proliferation as well as the formation of new tissues,and even limits the diffusion of nutrients and cellular metabolic waste inside and outside the gel.In order to overcome these shortcomings,some scholars have used various methods to create large pores in the gel structure.Among them,the introduction of large pores by the pore leaching method can conveniently control the porosity in the gel and facilitate the study of macroporous structures.Induction of cell behavior and new tissue formation.Although macroporous hydrogel scaffolds have made great progress in three-dimensional cell culture and tissue engineering in recent years,they still faces some challenges,including the formation of larger pores in the gels which can result in a substantial increase in the permeability of the gel structure,and in turn leads to rapid diffusion of nutrients and accelerates the rate of degradation of the hydrogel.To this end,it is desirable to promote cell proliferation and adhesion by designing or introducing biologically active factors.In this work,a novel enzyme-catalyzed cross-linking hydrogel based on poly(L-glutamic acid)-g-tyramine/cRGDfk cyclic peptide(PLG-g-TA/RGD)was prepared for the investigation of adhesion and three-dimensional culture of hyaline chondrocytes.PLG-g-TA/RGD polymers could formed a hydrogel by self-crosslinking of the tyrosine group rapidly with the presence of horseradish peroxidase(HRP)and H2O2.The further research results revealed that both the gelation time and hydeogel mechanical strength were significantly enhanced with the presence of cRGDfk.More hyaline chondrocytes adhered to the surface of the cRGDfk containing hydrogel compared to the control group after 3 days incubation.The proliferation efficiency of hyaline chondrocyte in PLG-g-TA/RGD hydrogel was significantly higher than PLG-g-TA formed hydrogel after culture with 1,4 and 7 days respectively.The results of cells indicated that the obtained materials exhibited a good cell compatibility.Above all,the introduction of cRGDfk enhanced the potential application of PLG-g-TA hydrogel in terms of three-dimensional-cell culture.