Study On 3D Printing Nano-hydroxyapatite Reinforced Hydrogel Cartilage Scaffold

At present,cartilage damage caused by trauma,degeneration and various diseases is very common in orthopedics.Because of the poor repair ability of cartilage tissue,how to repair it is a clinical and medical problem.With the development and advancement of tissue engineering technology,the use of tissue engineering technology for cartilage tissue regeneration provides new possibilities for repairing cartilage defects.In recent years,many scholars have carried out extensive research on the preparation of cartilage tissue engineering scaffolds and cartilage tissue reconstruction.The use of bio-3 D printing technology to prepare hydrogel stents for cartilage construction has shown great potential in soft tissue repair.In recent years,hydrogel materials have been widely used in cartilage tissue engineering repair research,and become a hot spot in tissue engineering research.However,3D printed hydrogel stents have lower printing accuracy and poorer mechanical properties due to their softness and shrinkage tendency,which is not conducive to processing them into a biological stent having a certain structure.the paper proposes the use of cell-controlled assembly technology to prepare cartilage scaffolds.Based on the analysis and comparison of the commonly used materials of tissue engineering scaffolds,gelatin sodium alginate is selected as the basic material to enhance the basic hydrogel by compounding nano-hydroxyapatite.The gel material was prepared by using a cell-controlled assembly machine to prepare a hydrogel scaffold with different proportions of nano-hydroxyapatite,and the corresponding performance of the scaffold was characterized.The results showed that the nano-hydroxyphosphorus was compared with the gelatin sea/alginate scaffold.The addition of gray stone can improve the printing precision and improve the stability and mechanical strength of the stent.The experimentally measured elastic modulus is 24.16±1.09 Mpa.The addition of n-HAP can also adjust the surface roughness of the stent and improve the biodegradability of the stent.The swelling rate test after freeze-drying of the stent shows that the composite stent still has good water absorption,which is beneficial to the coagulation of chondrocytes.The interior of the gel material is free to penetrate,while facilitating the transport of hydrophilic nutrients and cellular metabolites.Then the paper studies the biocompatibility of nano-hydroxyapatite hydrogels and uses composite cell-associated assembly techniques for composite chondrocyte printing.The toxicity test of the 3D printed n-HAP composite hydrogel scaffold showed that the scaffold material showed no cytotoxicity and supported the adhesion and growth of mouse chondrocytes;the cartilage cells were printed using the cell-controlled assembly technique to print the cartilage scaffold,and the results showed printing.The scaffold has a high cell survival rate,and after one week of printing,the live/dead cells are detected,and the number of viable cells can reach more than 95%.The experimental results show that the biological scaffold prepared by the method provided by this method can better meet the requirements of cartilage tissue engineering,and provide technical support for the subsequent experimental study of the biological scaffold;n-HAP enhanced hydrogel as a requirement for stability and cells Compatible cartilage tissue engineering materials have application prospects.