Preparation And Performance Study Of Nd-Ca-Si Based Multifunctional Bioactive Materials

Biomaterials with photothermal effects and tissue repair capabilities have huge application prospects in the field of regenerative medicine.However,an infrared thermal imager is used to measure the surface temperature of an organism generally,which cannot accurately measure the actual temperature of the location of the material,and cannot know the actual state of the material's degradation in the organism.Therefore,it is of great significance to prepare a multifunctional photothermal material with both temperature monitoring and tissue regeneration bioactivity.Based on the existing photothermal materials,we constructed a multifunctional Nd-Ca-Si-based biomaterial with photothermal therapy,temperature measurement and bioactive,and explored its physical and chemical properties and bioactivity.The main contents and results of this article are as follows:The Nd-Ca-Si based bioceramic materials(Nd/CS)was successfully prepared by using the dual-function rare earth Nd³⁺ion with photothermal/fluorescent properties as the photothermal agent and fluorescent agent and calcium silicate-based material(CaSiO₃,CS)as the matrix.Nd/CS ceramic powder was mainly composed of CS,and Nd ions were present in neodymium-rich apatite phase(Ca₂Nd₈(SiO₄)₆O₂)and neodymium silicate phase(Nd₂Si₂O₇).The photothermal/fluorescence and temperature monitoring performances of Nd/CS powder were explored.The results showed that Nd/CS ceramic powder had good photothermal and fluorescence performance.And the content of ceramic powder had a direct influence on the photothermal performance of the powder.Taking into account the application of soft tissue damage repair,the Nd/CS ceramic powder and polycaprolactone(PCL)were compounded by electrospinning technology to prepare a multifunctional composite membrane.The performance characterization of the composite membrane found that the composite membrane had similar photothermal and fluorescence properties to the ceramic powder.Preliminary cell experiments further confirmed that the composite membrane had good bioactivity.The Nd/CS powder and its composite membrane prove that the Nd-Ca-Si-based bioceramic is a potential biomaterial.Based on the research of Nd-Ca-Si-based bioceramic in the first part of the work,Nd-doped calcium silicate(CaSiO₃,CS)bioglass(Nd/CS)was prepared by containerless processing technology.The microscopic morphology,particle size,photothermal,fluorescence and temperature monitoring performance of Nd/CS glass were explored.The results showed that the prepared Nd/CS bioglass powder was micron-sized irregular particles,and the glass powder had excellent photothermal/fluorescence properties.Considering the application of the powder,an injectable composite hydrogel(Nd-BG2-SA)for tumor treatment was prepared by cross-linking Nd/CS2 bioglass powder with sodium alginate.The micromorphology,particle distribution,photothermal/fluorescence and ion release properties of the composite hydrogel were characterized.It was found that the composite hydrogel had good injectability,the powder distribution in the hydrogel was uniform,and the powder maintained excellent photothermal/fluorescence properties and temperature monitoring performance.Explore the effect of composite hydrogel extract on human umbilical vein endothelial cells.In vitro cell experiments showed that the composite hydrogel extract had superior bioactivity,which could promote the proliferation and migration of cells,the formation of angiogenic ring and the genes expression related to angiogenesis.Then,the biological properties of the composite hydrogel in vivo were explored,including tumor treatment,the degree of burned by different photothermal temperatures,the ability of the composite hydrogel to repair burn tissues,and the degradation performance of the composite hydrogel.The results showed that the composite hydrogel could effectively eliminate tumor cells at a certain temperature and promote the regeneration of burn tissues.Degraded ions were excreted with stool and urine,which had non-toxic effect on organisms.Based on the excellent photothermal/fluorescence performance and bioactivity of Nd-Ca-Si-based biomaterials,the Nd-Ca-Si-based Nd-doped hardystonite(Ca₂Zn Si₂O₇,HAr)bioceramic powder(Nd/HAr)was successfully prepared by the sol-gel method.The effects of different heat treatment temperatures on the photothermal/fluorescence properties of Nd/HAr ceramic powders were explored,and Nd/HAr ceramic powders sintered at the 1150?were selected for subsequent experiments in consideration of the photothermal/fluorescence properties.HAr1 and HAr coatings were prepared by deposition of HAr and Nd/HAr1 powder on the surface of titanium alloy substrate by vacuum plasma spraying technology(VPS).The phase conposition,microscopic morphology,bonding strength,photothermal and fluorescence performance of the coatings were characterized.The results showed that the ceramic powder on the coating surface transformed into a glass-ceramic phase;the surface of the coating was rough and uneven,which facilitated cell adhesion;the bonding strength of the HAr and the HAr1 coating reaches 34 Mpa and 37 Mpa respectively,and had good stability.The coating still maintained excellent photothermal/fluorescence performance.Interestingly,after spraying the HAr powder without photothermal performance,the coating had photothermal performance.Using electrospinning technology,a double-layer drug-carrying composite membrane was added to the coatings to obtain the antibacterial composite coatings H and H1.In vitro antibacterial experiments with staphylococcus aureus showed that the antibacterial performance of the H1 composite coating integrated with antibacterial ions/photothermal therapy/drugs was significantly better than that of single ion antibacterial,photothermal antibacterial,and drugs antibacterial and the combination of them.The proliferation and adhesion experiments of rabbit bone marrow mesenchymal stem cells showed that the H1 composite coating had excellent bioactivity.In summary,we prepared a multifunctional Nd-Ca-Si-based biomaterial system,and explored the physical and chemical properties,bioactivity and applications.From simple Nd-doped calcium silicate ceramics,to Nd-doped calcium silicate bioglasses with multiple functions,and then to the Nd-doped hardystonite antibacterial coating with complex substrates,the potential biological applications of Nd-Ca-Si-based biomaterials were explored gradually.The research results of this thesis also laid the foundation for the development and utilization of multifunctional biomaterials.