| 3d printing is a new kind technology of customized,personalized producing of different complex parts,it can produce the artificial bone as different requirement and different shape to adapt the different person due to the 3d printing’s ability to customize producing,it can even change the internal hole structure,porosity,etc of artificial bone to create more favorable conditions for the growth of cells.At the same time,it can reduce the infection of materials and enhance the function of bone repair through drug loading in the materials.Polylactic acid has the good biocompatibility and mechanical properties which makes it to be the main material of 3d printing.Nowadays,most studies of artificial bone fucoused on one main component of bone substitutes,such as hydroxyapatite,hydroxy calcium phosphate,tricalcium phosphate,etc,but the degree of inorganic particles dispersed in the organic phase is not good enough,the interface bonding is not strong,and a single components is difficult for bones’repairing compared with the native bone,most of the artificial bone material just can increase bone conduction,but they don’t have the bone induced,and the bone induced is a very important factor in bone repairing,so this article use the bone meal as part of the biological material directly,and use the drug-loaded 3d printing material to provide a stable anti-inflammatory sterilization environment with a long release cycle.The main contents of this study include:By using protein enzyme in advance,to get rid of lipase treatment such as pig residue on the surface of the humerus,then bone powder of different grain size is obtained by way of nanometer grinding,and finally,we found the best size is less than 10 um size for 3d printing optimum particle size of the preparation for composite materials,and then we increases the dispersion of particles in composite materials through the surface modification,and then we get the bone powder particle materials what we need;It has changed the material itself and the degradation rate of PLA,and the bone repair power with the PBSA added,and the mechanical properties of the whole materials have been greatly improved,too.We can get and the final bone matrix and different proportions of composite materials through the screw extruder and other preparation of polymer molding process,and get the optimum modification method,the final PBSA content is 10%,the modified bone dust content is 10%,which has the best mechanical property,the tensile strength is 48.5 MPa,the bending strength is 79.1 MPa,and the impact strength of the notch is 15.8 k J·m-2,and we finally producing the 3d printing filament with the bone dust,the filament diameter is1.75+/-0.3 mm,and the best extrusion temperature is 165℃for first area,170℃for second area,175℃for third area,170℃for fourth area,We use the SEM,FTIR and TG,mechanical performance test to test the filament,and the 3d printing test for it.The preparation of drug/PLA composite materials,we prepare the nano calcium carbonate particles by microemulsion method as the granular materials,and use the silane coupling agent KH550 for the surface modification of nanoparticles which can increase the drug-loading rate without rudcing the basic mechanical properties,the drug loading rate increased from 3%to nearly 64%and we use the SEM,FTIR,XRD,mechanical properties test for drug-loading particles,etc.,in order to study the mechanism of composite,and confirmed its slow release cycle can cooperate with the process of bone repair by the slow release for material of drug testing,the sustained release period was confirmed to be nearly90 days,then using the same technology preparation of 3d printing drug-loaded material to producing the 3d filament,and do the 3d printing testing for it.It will take drug-loade PLA material 3d filament and the bones dust PLA material 3d filament for 3d printing test with the double nozzle 3d printer,then do the biological experiments,cell toxicity test,blood compatibility test,cell adhesion test,etc with the material,the cell survival rate of each sample is higher than 90%after 1 week,the toxicity of each sample is basically level 0 or 1,the blood compatibility test shows that the hemolysis value is less than 15%at the lower 1000μg/m L,the antimicrobial experiments show that the material has certain antimicrobial properties and finally,it proved has the excellent biocompatibility and good bone induced growth in animals body.Final we composited the printing temperature is 200℃,the printing speed is 60 mm/s.The material made from bone materials and bones dust PLA material has good biocompatibility and biological safety,and it is expected to become the artificial bone repair materials with the a certain antibacterial material in the field of 3d printing. |
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