Preparation And Biocompatibility Of An Injectable Hydrogel

Tissue engineering combines the theories and methods of life sciences and engineering science,to develop new clinic substitute for human tissue and apparatus.Its typical method is seeding cells in the artificial extracellular matrix(ECMs) to form cells/artificial ECMs constructs.The main idea of this study is to find a kind of thermally sensitive hydrogel,and to detect the biocompatibility of it.A novel injectable temperature-sensitive chitosan/glycerophosphate/collagen(C/GP/Co) hydrogel was firstly prepared.2.15%(w/w) chitosan solution and 50%(w/w)β-glycerophosphate solution were mixed with a certain proportion to get chitosan/glycerophosphate solution,and then 2 mg·mL^-1 prepared collagen solution was mixed into the previous solution to get the C/GP/Co hydrogel.The gel-formation time was measured at 37℃,the micro structure of this hydrogel was observed under scanning electron microscope,and the osmolality of the media within the hydrogels was also assayed.In order to determine the biocompatibility of the injectable C/GP/Co hydrogel prepared,adipose tissue-derived stem cells(ADSCs) were cultured as seeding cells.Then the ability of proliferation and differentiation were determined.The ADSCs were seeded on the surface of C/GP/Co hydrogels,and the cell growth status was assayed under inverted microscope,the cell proliferation was detected by using CCK-8 kits and the cell apoptosis was observed by LIVE/DEAD Viability/Cytotoxicity kits.Finally,the growth of ADSCs within the C/GP/Co hydrogels was also evaluated by using CCK-8 kits and scanning electron microscopy(SEM).The results showed that the gel-formation time of the C/GP/Co hydrogel was about 12 min at 37℃,the inside of hydrogel presented spongy porous structure and the pore size was 100-150μm,the osmolality of media was in the range of 310-330 mmol·kg^-1.All these results indicate that the C/GP/Co hydrogels are feasible for cell culture.The ADSCs appeared to adopt a uniform shuttle shape and attached to the flask.They can differentiate into adipocytes, osteoblas and chondroblasts.After 7 days culture,the stem cells seeded on the surface of the C/GP/Co hydrogels showed typical cell morphology and presented good proliferation and very high cell viability.The ADSCs were also encapsulated within the hydrogels and demonstrated normal shuttle morphology.It is confirmed that the novel C/GP/Co hydrogel possesses excellent cell compatibility,and thus is a favourable scaffold for tissue engineering.