Visualization Of Biomaterials In Tissue Engineering Repair And Tumor Therapy

The development of new multifunctional biomaterials is expected to improve the effect of tumor therapy and realize the repair of tissue defects,providing a new idea for the combination of tissue engineering and tumor therapy.The integrated treatment of tumor treatment and tissue repair can carry different types of cells and drugs through a variety of biological materials to remove residual tumor cells and prevent tumor metastasis after surgery.At the same time,the design of biological materials can promote cell migration,proliferation,and differentiation to restore normal tissue structure and function,and avoid damage caused by multiple operations to the body.Therefore,the development of an integrated treatment and repair program has gradually become an emerging strategy.At the same time,the use of fluorescence imaging technology and magnetic imaging technology(MRI)can track cells,drugs,and scaffold materials,and provide guidance for the design of tissue engineering materials.In this paper,two different visualization tissue repair materials are constructed,which are expected to be used in the postoperative treatment and repair of bone cancer and breast cancer.Fluorescence imaging and magnetic imaging can monitor and track two biological materials to realize the visualization of the treatment and repair process.This subject is divided into two parts:The first part designed a visual hydrogel that can be used for dual-mode imaging for bone repair.In this experiment,a Gd-protoporphyrinPEG4000/?-cyclodextrin hydrogel was prepared for bone repair guided by fluorescence and magnetic imaging,the macrophages RAW264.7 and bone morphogenetic protein(BMP-2)were loaded into the hydrogel to provide conditions for the repair of bone defect tissue.The hydrogel system had high biocompatibility and low toxicity.The macrophage RAW264.7 in the hydrogel can survive stably and secrete factors through synergy with endogenous macrophages to recruit more endogenous cells.BMP-2 can stimulate the proliferation of mesenchymal stem cells and promote the proliferation of osteoblasts,and increase the secretion of macrophage chemokines to recruit more endogenous macrophages.In addition,the combination of multi-spectral fluorescence analysis technology and MRI can overcome the shortcomings of poor fluorescence imaging penetration and low magnetic imaging sensitivity to realize the real-time tracking of cells,drugs,and stents,which provided visualization of the tissue engineering material system for bone repair.The second part of the study designed a visual hydrogel/polylactic acid 3D printed scaffold that integrates tumor treatment and tissue repair.In this part of the experiment,a CpG-Fe3O4 nanoparticle hydrogel/polylactic acid scaffold for photothermal combined immunotherapy using magnetic imaging guidance was prepared.Oligonucleotide(CpG)combined with Fe3O4 nanoparticles improved the phagocytosis of DC and enhanced the immunostimulatory effect.Fe3O4 nanoparticles had a good photothermal effect,which can be applied to postoperative photothermal therapy for breast cancer(4T1).A large number of tumor-associated antigens and CpG adjuvants stimulated the body's immune system to exert a stronger immune effect and effectively inhibited the recurrence of tumor.The hydrogel/polylactic acid 3D printed scaffold provided conditions for the slow and controlled release of nano-drugs in the body and provided space for adhesion and growth of mouse epithelial cells(HC11).which was expected to provide a feasible solution for breast tissue regeneration.The superparamagnetism of Fe3O4 nanoparticles provided imaging conditions for the tracking of the scaffold.The MRI rat imaging research system can be used to locate and track the hydrogel.In summary,this article designed two different types of biomaterials for the treatment of bone defects and breast cancer,and evaluated the therapeutic effect through immunological indicators.Magnetic imaging and fluorescence imaging were used as monitoring methods to track cells,drugs,and scaffolds in the treatment and repair system,which provided guidance for the design of visual tissue engineering materials.