BACKGROUND:In recent years,methods for incorporating biominerals into bone tissue engineering scaffolds have been extensively studied,including solvent casting,freeze-drying,and 3D printing.However,the diverse types and complex compositions of biominerals lead to varying impacts on scaffold performance and differing requirements for fabrication processes,necessitating systematic research on their applicability.OBJECTIVE:To explore biomineral grinding and screening processes,and evaluate their solution rheological properties,hydrophilicity,mechanical properties,and biocompatibility when prepared as composite materials with polymer materials.METHODS:Five representative biominerals were selected,including turtle shell,eggshell,cuttlebone,deer antler,and pearl.These were ground into powders and screened,then mixed with polycaprolactone in specific proportions to prepare composite materials.The feasibility of applying biominerals in bone tissue engineering was explored by testing the elemental composition and particle size distribution of the powder,as well as the solution rheological properties,hydrophilicity,mechanical properties,and biocompatibility of the composite material.RESULTS AND CONCLUSION:(1)Most biomineral powders followed the rule that the longer the grinding time,the smaller the particle size.The desired particle size range could be obtained through methods such as sieving.Elemental mapping and Fourier Transform Infrared spectroscopy analyses indicated that the main inorganic mineral components of these five biominerals were calcium carbonate and calcium phosphate,containing the elements C,O,P,and Ca.(2)The method of dissolving polycaprolactone in 1,4-dioxane and adding biomineral powders to prepare scaffolds did not significantly alter the composite material composition and did not reduce biocompatibility.The addition of biomineral powders improved the hydrophilicity and 3D printability of polycaprolactone materials but decreased their mechanical properties.(3)These findings suggest that when applying biomineral powders to bone tissue engineering scaffolds,the proportion of powder added should be carefully chosen to balance hydrophilicity,printability,and mechanical properties.

BACKGROUND:In recent years,methods for incorporating biominerals into bone tissue engineering scaffolds have been extensively studied,including solvent casting,freeze-drying,and 3D printing.However,the diverse types and complex compositions of biominerals lead to varying impacts on scaffold performance and differing requirements for fabrication processes,necessitating systematic research on their applicability.OBJECTIVE:To explore biomineral grinding and screening processes,and evaluate their solution rheological properties,hydrophilicity,mechanical properties,and biocompatibility when prepared as composite materials with polymer materials.METHODS:Five representative biominerals were selected,including turtle shell,eggshell,cuttlebone,deer antler,and pearl.These were ground into powders and screened,then mixed with polycaprolactone in specific proportions to prepare composite materials.The feasibility of applying biominerals in bone tissue engineering was explored by testing the elemental composition and particle size distribution of the powder,as well as the solution rheological properties,hydrophilicity,mechanical properties,and biocompatibility of the composite material.RESULTS AND CONCLUSION:(1)Most biomineral powders followed the rule that the longer the grinding time,the smaller the particle size.The desired particle size range could be obtained through methods such as sieving.Elemental mapping and Fourier Transform Infrared spectroscopy analyses indicated that the main inorganic mineral components of these five biominerals were calcium carbonate and calcium phosphate,containing the elements C,O,P,and Ca.(2)The method of dissolving polycaprolactone in 1,4-dioxane and adding biomineral powders to prepare scaffolds did not significantly alter the composite material composition and did not reduce biocompatibility.The addition of biomineral powders improved the hydrophilicity and 3D printability of polycaprolactone materials but decreased their mechanical properties.(3)These findings suggest that when applying biomineral powders to bone tissue engineering scaffolds,the proportion of powder added should be carefully chosen to balance hydrophilicity,printability,and mechanical properties.

The organ-system-based curriculum (OSBC) medical teaching model with the organ system as the main line closely links the basic medical curriculum with the clinical practice,and breaks the boundaries between different subjects.As this novel teaching model is still in the early stage in China,Chongqing Medical University pioneered to reconstruct the teaching system for OSBC teaching reform,including the great efforts to integrate e the traditional 24 courses into 12,and to allocate talents from various basic and clinical teaching departments to form a new integrated teaching team.In 2011,this new mode was implemented in a pilot class of students.The results showed the 2011 five-year pilot class showed more satisfaction than did the traditional teaching class [(92.5 ± 4.6)％ vs.(72.5 ± 4.9)％,P＜0.05].Besides,the test scores of the pilot class and the traditional class were (80.0 ± 3.6) and (71.0 ± 5.9) respectively(P＜0.05),and the failing rate was (3.7％ in pilot class and 9.3％ in traditional class(P＜0.05).Since the pilot class perform better than the traditional one,the reform of OSBC was implemented for all five-year clinical medicine program in Chongqing Medical University in 2018.