Bone defects are common clinical problems in the world,and there are many biomaterials used for treat-ing them.However,there is still a paucity of bioactive materials capable of modulating the immune mi-croenvironment...Bone defects are common clinical problems in the world,and there are many biomaterials used for treat-ing them.However,there is still a paucity of bioactive materials capable of modulating the immune mi-croenvironment.Therefore,it is necessary to identify new therapeutic strategies to regulate the immune microenvironment of the bone defect to further promote osteogenesis.Hydroxyapatite(HAP)is an impor-tant mineral for the framework of the human body.Recently,HAP has become a key research object for bone tissue engineering applications due to its unique tailored properties and similarity to bone tissue.Here,we prepared rod-shaped HAP(rHAP)with different concentrations(0,100,200,and 300μg/mL).The slowly released Ca^(2+)of 200μg/mL rHAP can induce macrophage phenotype 2(M2)polarization to decrease inflammatory cytokine secretion via the PI3K-Akt and Wnt/β-catenin pathways.In addition,rHAP can induce osteogenesis through the osteogenic differentiation of rat bone marrow mesenchymal stem cells.In conclusion,the 200μg/mL rHAP shows the potential for osteoimmunomodulation in a bone defect in vitro and in vivo,which is beneficial to the treatment of bone defects.展开更多
Biocompostable poly(glycolic acid)(PGA)crystallizes slowly under fast cooling condition,leading to poor mechanical performance of the final products.In this work,a self-nucleation(SN)route was carried out to promote t...Biocompostable poly(glycolic acid)(PGA)crystallizes slowly under fast cooling condition,leading to poor mechanical performance of the final products.In this work,a self-nucleation(SN)route was carried out to promote the crystallization of PGA by regulating only the thermal procedure without any extra nucleating agents.When self-nucleation temperature(Ts)decreased from 250℃ to 227℃,the nuclei density was increased,and the non-isothermal crystallization temperature(Tc)of PGA was increased from 156℃ to 197℃ and the half-life time(t0.5)of isothermal crystallization at 207℃ was decreased by 89%.Consequently,the tensile strength and the elongation at break of the PGA were increased by 12%and 189%,respectively.According to the change of Tc as a function of Ts,a three-stage temperature domain map(Domain I,II and III)was protracted and the viscoelastic behavior of the self-nucleation melt and the homogeneous melt was studied.The results indicated that interaction among PGA chains was remained in Domain IIb,which can act as pre-ordered structure to accelerate the overall crystallization rate.This work utilizes a simple and effective SN method to regulate the crystallization behavior and the mechanical properties of PGA,which may broaden the application range of resulting materials.展开更多
基金This work was funded by the National Key Research and Development Program(Grant No.2020YFC2009004)the National Natural Science Foundation of China(Grant no.52172282)+1 种基金the China Postdoctoral Science Foundation(Grant No.2021M690106)the New clinical practical technology in the Medical Affairs Department of the Qilu Hospital of Shandong University(Grant No.2019-08).We thank the Translational Medicine Core Facility of Shandong University for their consultation and instruments that supported this work.
文摘Bone defects are common clinical problems in the world,and there are many biomaterials used for treat-ing them.However,there is still a paucity of bioactive materials capable of modulating the immune mi-croenvironment.Therefore,it is necessary to identify new therapeutic strategies to regulate the immune microenvironment of the bone defect to further promote osteogenesis.Hydroxyapatite(HAP)is an impor-tant mineral for the framework of the human body.Recently,HAP has become a key research object for bone tissue engineering applications due to its unique tailored properties and similarity to bone tissue.Here,we prepared rod-shaped HAP(rHAP)with different concentrations(0,100,200,and 300μg/mL).The slowly released Ca^(2+)of 200μg/mL rHAP can induce macrophage phenotype 2(M2)polarization to decrease inflammatory cytokine secretion via the PI3K-Akt and Wnt/β-catenin pathways.In addition,rHAP can induce osteogenesis through the osteogenic differentiation of rat bone marrow mesenchymal stem cells.In conclusion,the 200μg/mL rHAP shows the potential for osteoimmunomodulation in a bone defect in vitro and in vivo,which is beneficial to the treatment of bone defects.
基金the National Natural Science Foundation of China(Nos.51873082,52073123 and 52103032)the Distinguished Young Natural Science Foundation of Jiangsu Province(No.BK20200027)the Natural Science Foundation of Jiangsu Province(No.BK20200606).
文摘Biocompostable poly(glycolic acid)(PGA)crystallizes slowly under fast cooling condition,leading to poor mechanical performance of the final products.In this work,a self-nucleation(SN)route was carried out to promote the crystallization of PGA by regulating only the thermal procedure without any extra nucleating agents.When self-nucleation temperature(Ts)decreased from 250℃ to 227℃,the nuclei density was increased,and the non-isothermal crystallization temperature(Tc)of PGA was increased from 156℃ to 197℃ and the half-life time(t0.5)of isothermal crystallization at 207℃ was decreased by 89%.Consequently,the tensile strength and the elongation at break of the PGA were increased by 12%and 189%,respectively.According to the change of Tc as a function of Ts,a three-stage temperature domain map(Domain I,II and III)was protracted and the viscoelastic behavior of the self-nucleation melt and the homogeneous melt was studied.The results indicated that interaction among PGA chains was remained in Domain IIb,which can act as pre-ordered structure to accelerate the overall crystallization rate.This work utilizes a simple and effective SN method to regulate the crystallization behavior and the mechanical properties of PGA,which may broaden the application range of resulting materials.
