Chitosan is a natural, biodegradable cationic polysaccharide, which has a similar chemical structure and similar biological behaviors to the components of the extracellular matrix in the biomineralization process of teeth or bone. Its excellent biocompatibility, biodegradability, and polyelectrolyte action make it a suitable organic template, which, combined with biomimetic mineralization technology, can be used to develop organic-inorganic composite materials for hard tissue repair. In recent years, various chitosan-based biomimetic organic-inorganic composite materials have been applied in the field of bone tissue engineering and enamel or dentin biomimetic repair in different forms (hydrogels, fibers, porous scaffolds, microspheres, etc.), and the inorganic components of the composites are usually biogenic minerals, such as hydroxyapatite, other calcium phosphate phases, or silica. These composites have good mechanical properties, biocompatibility, bioactivity, osteogenic potential, and other biological properties and are thus considered as promising novel materials for repairing the defects of hard tissue. This review is mainly focused on the properties and preparations of biomimetically mineralized composite materials using chitosan as an organic template, and the current application of various chitosan-based biomimetically mineralized composite materials in bone tissue engineering and dental hard tissue repair is summarized.

Spinal cord injury (SCI) is a devastating disease that results in severe motor, sensory, and autonomic dysfunction, for which there is currently no available treatments. Following the primary mechanical damage, progressive secondary damage further exacerbates the functional deficit. Demyelination may play an important role in the pathogenesis of SCI. Oligodendrocyte progenitor cells (OPCs) are considered a candidate cellular treatment approach for SCI due to their unique potential. Here, we conducted a systematic review and meta-analysis to assess the efficacy of OPC transplantation in rat models with traumatic thoracic SCI and 17 studies (20 experiments, 402 rats) were identified. The Basso, Beattie, Bresnahan locomotor rating score (BBB) score, latency and amplitude of Motor Evoked Potential (MEP), percentage of myelinated axons, and cavity size were used as outcome measurements. The pooled results of the meta-analysis in different subgroups (based on cell dose or gender) both suggested that the BBB score of the OPC group was significantly improved compared to that of the control group 2, 4, and 8 weeks after transplantation. While the amplitude of MEP was not significantly different, the latency of MEP was significantly shorter compared to that of the control group 4 weeks after transplantation. The percentage of myelinated axons increased significantly in the OPC group compared to that of the control group following OPC transplantation. Area measurements across groups revealed a significant reduction in cavity size in the OPC-treated groups compared with the control group. In conclusion, OPC transplantation provided considerable beneficial effects following traumatic SCI.

Bioactive natural products have become a hot spot for oral disease treatments. At the present study, LongZhang Gargle was investigated for its effects on single‐species biofilms of Candida albicans and dual‐species biofilms of Candida albicans and Streptococcus mutans. Two different models of single and dual‐species biofilms were grown in YNBB medium under appropriate conditions. Biofilm biomass, biofilm architecture, and cell activity in biofilms were assessed using Crystal Violet Staining, MTT, scanning electron microscopy (SEM), and confocal laser scanning microscopy (CLSM). Significant reductions of biofilm biomass and fungus activity were obtained when treated with LongZhang Gargle at 2% (P < 0.05), 4% (P < 0.05), and 8% (P < 0.05) in single‐species biofilms of C. albicans, and at 4% (P < 0.05) and 8% (P < 0.05) in double‐species biofilms. Suppression of density, thickness, and the proportion of hyphae and fungal spores were obtained under SEM and CLSM. In conclusion, LongZhang Gargle affects single and dual‐species biofilms by inhibiting biofilm biomass, cell activity, and formation of hyphae, but it does not affect the production of Extracellular polysaccharides (EPS). We speculate that LongZhang Gargle would be a promising natural drug, which can be used in treatment against C. albicans and S. mutans in oral diseases.