A type of polymer/ceramic coating was introduced on a magnesium-based nanocomposite, and the nanocomposite was evaluated for implant applications.The microstructure, corrosion, and bioactivity of the coated and uncoat...A type of polymer/ceramic coating was introduced on a magnesium-based nanocomposite, and the nanocomposite was evaluated for implant applications.The microstructure, corrosion, and bioactivity of the coated and uncoated samples were assessed.Mechanical alloying followed by sintering was applied to fabricate the Mg–3Zn–0.5Ag–15NiTi nanocomposite substrate.Moreover, different contents of poly(lactic-co-glycolic acid)(PLGA) coatings were studied, and 10 wt% of PLGA content was selected.The scanning electron microscopy(SEM) images of the bulk nanocomposite showed an acceptable homogenous dispersion of the Ni Ti nanoparticles(NPs) in the Mg-based matrix.In the in vitro bioactivity evaluation, following the immersion of the uncoated and coated samples in a simulated body fluid(SBF) solution, the Ca/P atomic ratio demonstrated that the apatite formation amount on the coated sample was greater than that on the uncoated nanocomposite.Furthermore, assessing the corrosion resistance indicated that the coatings on the Mg-based substrate led to a corrosion current density(icorr) that was considerably lower than that of the substrate.Such a condition revealed that the coating would provide an obstacle for the corrosion.Based on this study, the PLGA/hardystonite(HT) composite-coated Mg–3Zn–0.5Ag–15NiTi nanocomposite may be suitably applied as an orthopedic implant biomaterial.展开更多
Eyeball loss due to severe ocular trauma,intraocular malignancy or infection often requires surgical treatment called orbital implant reconstruction to rehabilitate the orbital volume and restore the aesthetic appeara...Eyeball loss due to severe ocular trauma,intraocular malignancy or infection often requires surgical treatment called orbital implant reconstruction to rehabilitate the orbital volume and restore the aesthetic appearance.However,it remains a challenge to minimize the postoperative exposure and infection complications due to the inert nature of conventional orbital implants.Herein,we developed a novel Ca-Zn-silicate bioceramic implant with multi-functions to achieve the expected outcomes.The porous hardystonite(Ca2ZnSi2O7)scaffolds with triply periodic minimal surfaces(TPMS)-based pore architecture and graded pore size distribution from center to periphery(from 500 to 800μm or vice versa)were fabricated through the digital light processing(DLP)technique,and the scaffolds with homogeneous pores(500 or 800μm)were fabricated as control.The graded porous scaffolds exhibited a controlled bio-dissolving behavior and intermediate mechanical strength in comparison with the homogeneous counterparts,although all of porous implants presented significant antibacterial potential against S.aureus and E.coli.Meanwhile,the pore size-increasing scaffolds indicated more substantial cell adhesion,cell viability and angiogenesis-related gene expression in vitro.Furthermore,the gradually increasing pore feature exhibited a stronger blood vessel infiltrating potential in the dorsal muscle embedding model,and the spherical implants with such pore structure could achieve complete vascularization within 4 weeks in the eyeball enucleation rabbit models.Overall,our results suggested that the novel antibacterial hardystonite bioceramic with graded pore design has excellent potential as a next-generation orbital implant,and the pore topological features offer an opportunity for the improvement of biological performances in orbital reconstruction.展开更多
基金the support provided by Islamic Azad University of Najafabad, Iran for this research。
文摘A type of polymer/ceramic coating was introduced on a magnesium-based nanocomposite, and the nanocomposite was evaluated for implant applications.The microstructure, corrosion, and bioactivity of the coated and uncoated samples were assessed.Mechanical alloying followed by sintering was applied to fabricate the Mg–3Zn–0.5Ag–15NiTi nanocomposite substrate.Moreover, different contents of poly(lactic-co-glycolic acid)(PLGA) coatings were studied, and 10 wt% of PLGA content was selected.The scanning electron microscopy(SEM) images of the bulk nanocomposite showed an acceptable homogenous dispersion of the Ni Ti nanoparticles(NPs) in the Mg-based matrix.In the in vitro bioactivity evaluation, following the immersion of the uncoated and coated samples in a simulated body fluid(SBF) solution, the Ca/P atomic ratio demonstrated that the apatite formation amount on the coated sample was greater than that on the uncoated nanocomposite.Furthermore, assessing the corrosion resistance indicated that the coatings on the Mg-based substrate led to a corrosion current density(icorr) that was considerably lower than that of the substrate.Such a condition revealed that the coating would provide an obstacle for the corrosion.Based on this study, the PLGA/hardystonite(HT) composite-coated Mg–3Zn–0.5Ag–15NiTi nanocomposite may be suitably applied as an orthopedic implant biomaterial.
基金support from the National Natural Science Foundation of China(81870635,82000948)the National Key Research and Development Program of China(2017YFE0117700)and Natural Science Foundation of Zhejiang Province(LY20H120007).
文摘Eyeball loss due to severe ocular trauma,intraocular malignancy or infection often requires surgical treatment called orbital implant reconstruction to rehabilitate the orbital volume and restore the aesthetic appearance.However,it remains a challenge to minimize the postoperative exposure and infection complications due to the inert nature of conventional orbital implants.Herein,we developed a novel Ca-Zn-silicate bioceramic implant with multi-functions to achieve the expected outcomes.The porous hardystonite(Ca2ZnSi2O7)scaffolds with triply periodic minimal surfaces(TPMS)-based pore architecture and graded pore size distribution from center to periphery(from 500 to 800μm or vice versa)were fabricated through the digital light processing(DLP)technique,and the scaffolds with homogeneous pores(500 or 800μm)were fabricated as control.The graded porous scaffolds exhibited a controlled bio-dissolving behavior and intermediate mechanical strength in comparison with the homogeneous counterparts,although all of porous implants presented significant antibacterial potential against S.aureus and E.coli.Meanwhile,the pore size-increasing scaffolds indicated more substantial cell adhesion,cell viability and angiogenesis-related gene expression in vitro.Furthermore,the gradually increasing pore feature exhibited a stronger blood vessel infiltrating potential in the dorsal muscle embedding model,and the spherical implants with such pore structure could achieve complete vascularization within 4 weeks in the eyeball enucleation rabbit models.Overall,our results suggested that the novel antibacterial hardystonite bioceramic with graded pore design has excellent potential as a next-generation orbital implant,and the pore topological features offer an opportunity for the improvement of biological performances in orbital reconstruction.
