Synthesis Of Hydroxyapatite Composites And Their Applications In Drug Deliveries

Hydroxyapatite[Ca₁₀?PO₄?₆?OH?₂,HAp]has been widely used in repair of damaged bone,because of excellent biocompatibility and osteoconductivity,which is an important inorganic component of the human body's natural bones.Besides,it has also been applied to the fields of the separation of protein separation and the adsorption of toxic and harmful substances in the environment.After the human skeleton is damaged,it is necessary to take an anti-inflammatory drug in order to eliminate quickly the pain of damaged part and engage successfully with the filling material.However,the commonly used oral and in vitro injection methods cannot efficiently target the drug molecules to the damaged site.Therefore,the search for a new class of materials has become one of the research hotspots in the medical field,that can achieve target controlled release of drugs.Such materials need to have good adsorption and controlled release properties.Studies have shown that the adsorption efficiency of HAp nanoparticles is still low,which greatly limits the application of such materials in drug carriers,catalysis and environmental remediation.At present,composite technology is an important way to improve and regulate the performance of nanomaterials.In this dissertation,hydroxyapatite and other biologically active materials such as SiO₂ and magnetic materials are attempted to synthesize novel drug carriers provided with both biological activity and special structures.These new synthetic materials can carry drug molecules to fill in damaged bones and perform controlled target release.HAp@m SiO₂ with mesoporous structure was synthesized by sol-gel method in this study.From the result of a series of characterizations,this material has advantages of large specific surface area,narrow pore size distribution,and morphological controllability.In simulation experiments of vitro drug loading and release,the effects of shell thickness and pH on its drug release properties were investigated.In order to improve the drug loading efficiency and release about new synthetic materials,this study also tried to use the hard template method to synthesize novel hollow mesoporous silica nanorods on the basis of core-shell materials,and explored the effects of the morphology and pH value on the drug release properties.At last,HAp hollow spheres doped with magnetic materials were synthesized by in-situ replacement method,and the effects of doping amount,magnetic strength and pH value of magnetic materials were investigated.This new material with special structure shows its drug loading and controlled release characteristics to varying degrees,and improves the traditional application of hydroxyapatite as a bone filling material.It will has a wide range of application prospects in the biomedical field..