BACKGROUND:Poly(lactic-co-glycolic acid)copolymer with good biosafety,biodegradability,and superior mechanical properties has become a focal point of research in stomatology.OBJECTIVE:To review the advance in stomatology of poly(lactic-co-glycolic acid)copolymer.METHODS:Using a computer-assisted search of relevant literature published in the China National Knowledge Infrastructure(CNKI)and PubMed databases,the search terms included"polylactic acid-hydroxyacetic acid,PLGA,oral defect,tissue engineering"in Chinese,and"PLGA,polylactic acid-hydroxyacetic acid copolymer,poly(lactic-co-glycolic acid)copolymer,dent*,regeneration,caries,periodontal,pulp,implant,alveolar bone"in English.Preliminary screening was conducted by reading titles and abstracts,excluding literature unrelated to the theme of the article.Based on the inclusion and exclusion criteria,a total of 119 articles were included for review.RESULTS AND CONCLUSION:In the field of stomatology,the application scope of poly(lactic-co-glycolic acid)copolymer is rapidly expanding,gradually replacing the traditional therapeutic drugs and restorative materials.Poly(lactic-co-glycolic acid)copolymer nanoparticles/microspheres can carry a variety of hydrophobic and hydrophilic active substances,demonstrating excellent delivery capabilities in caries prevention,root canal disinfection,and pulp capping treatment.In periodontal therapy,poly(lactic-co-glycolic acid)copolymer is widely used as a barrier membrane and drug carrier for periodontal tissue regeneration.Poly(lactic-co-glycolic acid)copolymer used for surface modification of implants not only enhances the antibacterial ability of the implant surface but also improves the bio-inert nature of the implant surface.The effect of pure poly(lactic-co-glycolic acid)copolymer scaffolds on treating bone defects is limited and requires the integration of 3D printing,various bioactive components,and inorganic materials to enhance scaffold performance.The combination of poly(lactic-co-glycolic acid)copolymer and stem cells can improve the effectiveness of nerve therapy,meeting clinical needs.Based on the great potential of poly(lactic-co-glycolic acid)copolymer in the field of stomatology,it is expected that in the future,repair materials with specific functions for different diseases will be produced according to different needs of oral tissue engineering.

BACKGROUND:Poly(lactic-co-glycolic acid)copolymer with good biosafety,biodegradability,and superior mechanical properties has become a focal point of research in stomatology.OBJECTIVE:To review the advance in stomatology of poly(lactic-co-glycolic acid)copolymer.METHODS:Using a computer-assisted search of relevant literature published in the China National Knowledge Infrastructure(CNKI)and PubMed databases,the search terms included"polylactic acid-hydroxyacetic acid,PLGA,oral defect,tissue engineering"in Chinese,and"PLGA,polylactic acid-hydroxyacetic acid copolymer,poly(lactic-co-glycolic acid)copolymer,dent*,regeneration,caries,periodontal,pulp,implant,alveolar bone"in English.Preliminary screening was conducted by reading titles and abstracts,excluding literature unrelated to the theme of the article.Based on the inclusion and exclusion criteria,a total of 119 articles were included for review.RESULTS AND CONCLUSION:In the field of stomatology,the application scope of poly(lactic-co-glycolic acid)copolymer is rapidly expanding,gradually replacing the traditional therapeutic drugs and restorative materials.Poly(lactic-co-glycolic acid)copolymer nanoparticles/microspheres can carry a variety of hydrophobic and hydrophilic active substances,demonstrating excellent delivery capabilities in caries prevention,root canal disinfection,and pulp capping treatment.In periodontal therapy,poly(lactic-co-glycolic acid)copolymer is widely used as a barrier membrane and drug carrier for periodontal tissue regeneration.Poly(lactic-co-glycolic acid)copolymer used for surface modification of implants not only enhances the antibacterial ability of the implant surface but also improves the bio-inert nature of the implant surface.The effect of pure poly(lactic-co-glycolic acid)copolymer scaffolds on treating bone defects is limited and requires the integration of 3D printing,various bioactive components,and inorganic materials to enhance scaffold performance.The combination of poly(lactic-co-glycolic acid)copolymer and stem cells can improve the effectiveness of nerve therapy,meeting clinical needs.Based on the great potential of poly(lactic-co-glycolic acid)copolymer in the field of stomatology,it is expected that in the future,repair materials with specific functions for different diseases will be produced according to different needs of oral tissue engineering.

BACKGROUND:The mechanism of steroid-induced avascular necrosis of the femoral head is stil unclear, Cx43 protein as the main gap junction in bone tissue, through transmitting information between osteoblasts, regulates bone cel growth and differentiation, compensatory bone increase or decrease. The relationship between Cx43 protein and steroid-induced avascular necrosis of the femoral head is stil rarely reported.
OBJECTIVE:To explore the changes in Cx43 expression in rabbit models of steroid-induced vascular necrosis of the femoral head.
METHODS:Forty New Zealand rabbits were equal y and randomly divided into model group and control group. Rabbits in the model group were used to establish models of steroid-induced avascular necrosis of the femoral head using endotoxin and hormone. Rabbits in the control group were injected with the same volume of physiological saline at the same time points.
RESULTS AND CONCLUSION:At 4 weeks after model establishment, hematoxylin-eosin staining results revealed that in the model group, the trabecula became thin and distributed disorderly in the femoral subchondral area. Empty lacuna increased significantly. Adipocytes increased. Hematopoietic cel s in medul ary cavity apparently diminished. In the control group, trabecula arranged orderly and empty lacuna could be seen. Bone marrow cel s were abundant, but adipocytes were less. Immunohistochemical method demonstrated that Cx43 protein expression was observed in osteoblasts of the edge of trabecula, cytoplasm of osteoblasts of trabecula, and bone marrow stromal cel s. Western blot assay results showed that alkaline phosphatase and Cx43 protein expression was lower in the model group than in the control group (P<0.05). Results indicated that Cx43 protein expression decreased in the model rabbits, which may be the key link of the occurrence and development of steroid-induced avascular necrosis of the femoral head.