Research advances in application of stimuli-responsive hydrogels in bone repairation

Hydrogels with unique network structure, high levels of biocompatibility and hydrophilicity, and soft physical properties have been widely used in the biomedical science, especially in the tissue engineering. As one type of the novel smart materials, the stimuli-responsive hydrogels can not only contain the excellent properties of ordinary hydrogels, but also exhibit unique swelling or degradation behavior under the stimulation of external environment (e.g., temperature, pH, light and magnetic fields, et al). Thus, it can carry cell growth factors and be implanted into the defect tissues to achieve tissue damage repair and functional reconstruction. And this precise control of hydrogels makes the treatment of complex bone defect becomes minimally invasive. Based on different types of external environmental stimuli, we introduce the classification, stimulus response principle and the research advances in the stimuli-responsive hydrogels in bone repair, intending to provide new ideas and methods for the treatment of bone defect.