Study On Preparation And Osteogeneic Property Of Photoresponsive Nanofibers

Bone defect is a common clinical disease,which seriously affects the living quality of patients.In recent years,bone tissue engineering,an emerging technology,has provided a novel solution for the treatment of bone defects.It refers to the seed cells are planted on the scaffold supplemented with osteoinductive factors,and then transplanted to the defect site to assist and promote bone regeneration and repair.In particular,electrospinning technology has widely used in the preparation of bone tissue engineering scaffolds due to its ability to fabricate nanostructured scaffold and provide an excellent growth environment for seed cells.However,the osteoinductive factors carried by electrospinning nanofiber scaffold are mostly easy-deactivating and expensive growth factor.Besides,the regeneration of bone tissue cannot regulate in response to external stimulus.In this study,combined with photoresponsive nanomaterials（black phosphorus（BP）and MXene）and osteoinductive inorganic materials,we successfully fabricated two kinds of nanofibers scaffold with photothermal performance and osteogenic properties by electrospinning technology,which is based on poly-L-lactic acid（PLLA）,aiming to provide a reference for the preparation of stimulus-responsive engineering scaffold.The detail research contents and results are as follows:（1）Preparation of BP-CPO NFs and its osteogenic propertiesIn this section,we triumphantly prepared BP/CPO/PLLA NFs（BP-CPO NFs）by electrospinning process,which is composed of PLLA,BP nanosheets and calcium peroxide（CPO）.In the nanofibers,CPO reacts with water to not only release oxygen,but also delivers calcium ions;BP nanosheets impart photothermal performance to nanofibers and also supply phosphate to cell metabolism.Oxygen,calcium ions and phosphate,as inducing factor,synergistically promote the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells（BMSCs）.The results of SEM,Mapping and photothermal experiments demonstrated BP-CPO NFs with Photothermal performancewas was successfully fabricated;CCK-8 and cellular immunofluorescence assay showed that BP-CPO NFs promotes proliferation of BMSCs;ALP and ARS staining assay indicated that the excellent osteogenic properties of BP-CPO NFs was further enhanced under NIR exspoure;the results of subcutaneous ectopic osteogenic experiment in vivo demonstrated BP-CPO NFs has excellent biocompatibility and NIR-responsive osteogenic properties.Given the Photothermal performance,biocompatibility and controllable osteogenic properties of BP-CPO NFs,it can provide reference significance for the treatment of clinical bone defects and bone tissue-related diseases.（2）Preparation of M-@HA NFs and its osteogenic propertiesIn this section,HA-Si O₂NPs was prepared by loading nano-hydroxyapatite on mesoporous silica nanoparticles using biomineralization technique.Then it was mixed with MXene in polylactic acid solution,and HA-Si O₂NPs/MXene/PLLA NFs nanofibers（M-@HA NFs）were prepared by electrospinning.In the nanofibers,silica nanoparticles not only serve as the storage of mineral elements（Ca,P and Si）,but also can supply silicon ions for cellular metabolize;MXene nanosheets not only endows nanofibers with excellent Photothermal performance,but also can regulate the release of these mineral elements to enhance osteogenesis.TEM,XRD,Mapping and SEM asssay indicated M-@HA NFs was successfully preparation;cell compatibility experiments in vitro indicated that the nanofiber scaffold can enhance the metabolic vitality and proliferation of BMSCs;the results of osteogenesis evaluation experiments in vitro demonstarted that M-@HA NFs can promote the osteogenic differentiation of BMSCs.And under NIR 808 nm laser exposure,the osteogenic properties of M-@HA NFs were further enhanced.Considering its Photothermal performance,cellular compatibility and controllable osteogenic properties,M-@HA NFs has extensive potential applications in the field of bone tissue engineering and thermotherapy.