Biomimetic Design and Biocompatibility of Biomimetic Calcium Carbonate Nanocomposites for Skeletal Muscle Injury Repair

Abstract

As an important part of the human body, skeletal muscle is easily damaged in the process of exercise. The purpose of this study is to investigate the controllable construction and biocompatibility of biomimetic calcium carbonate nanocomposites in exercise skeletal muscle repair. In this study, adult healthy mice were selected as the research objects. First, the mice were anesthetized with 2.5% pentobarbital sodium. Then, the mice were fixed and hit with steel balls on the middle part of the gastrocnemius muscle abdomen to establish a skeletal muscle contusion model. The mice were killed by cervical dislocation under anesthesia. The injured gastrocnemius muscles were quickly removed to prepare the cell suspension. 0.8600 g chitosan was weighed and dissolved in 200 ml deionized water. Then, 0.0660 g of calcium chloride dihydrate was added and stirred to dissolve to prepare chitosan calcium carbonate composite. The calcium carbonate composite material with a length of 8.0 cm is cut into a square sheet of stainless steel. The stainless steel plate was sterilized and then placed in a 12 culture plate to dilute the full cells in the culture bottle. The cells were seeded in 12 well culture plates, and 100 μL cells and 600 μL medium were added to each well. The samples were cultured in the incubator (there were three control holes in each group for SEM test, three control holes for fluorescence measurement, and six control holes for MTT measurement). The plates were taken out and placed in a new 24 plate. 1000 μL medium was added. Then. 100 μL MTT solution was added into each well. The biocompatibility test was conducted for 4 h. The GSH PX level in the chitosan calcium carbonate composite group was lower than that in the natural recovery group ( $P<0.01$ ). The results showed that chitosan calcium carbonate composite could promote the growth of skeletal muscle cells.