The Research Of Rare Earth Doped Mesoporous Bioactive Glass Microspheres

Compared to the traditional bioactive glass(BG),Mesoporous bioactive glass(MBG)has attracted wide attention in the last decade because of its high specific surface area,pore volume,excellent bioactivity,biodegradability and drug controlled release.On the one hand,MBG can be used as bone filling material because of its excellent bioactivity,on the other hand,it can increase the specific surface area and pore volume because of the existence of mesoporous,whichi is beneficial to the proliferation and differentiation of bone cells and accelerate the repair of bone loss or bone defect.In addition,MBG posses high drug loading rate and can also used as a sustained release system for anticancer drugs,which can prolong the time of drug release and reduce the toxicity to human normal tissue cells due to the accumulation of anticancer drugs.Therefore,functional MBG has important research value and application prospect.Considering the role of light rare earth elements in inhibiting cancer and so on,in this paper,three rare earth elements of Ce,Eu and Nd were combined with MBG microspheres to prepare a kind of rare earth doped MBG microsphere functional composite carrier.The main work has completed in the following aspects.1.TEOS,TEP and CN are used as the main raw materials.Using CTAB as a sole template,two kinds of MBG 1 and MBG2 microspheres were synthesized by sol-gel method with ethyl acetate,deionized water and ethanol,deionized water as solvent,respectively.Then MBG microspheres were characterized using XRD,SEM,TEM,FTIR,XPS and so on.The experimental results showed that the two MBG microspheres synthesized by the sol-gel method have high specific surface area,excellent in vitro bioactivity,drug controlled release ability and non-cytotoxicity.However,MBG2 microspheres possess a high drug loading rate of 86.3%,and have better drug controlled release properties.2.The MBG2 microspheres were selected as the carrier.The rare earth doped MBG microspheres were synthesized by doping trace rare earth elements(Ce,Eu,Nd),and the basic characterization and testing of the microspheres were carried out.The experimental results show that the micro doping of rare earth does not change the morphology and size of the microspheres.The size of the microspheres is about 500 nm,but the rare earth doping will reduce the specific surface area of MBG,thus reducing the loading rate of DOX.However,the trace rare earth elements can play a controlled release of DOX,and then have a significant inhibitory effect on the activity of osteosarcoma MG-63 cells by by released DOX.And a proper amount of rare earth doped microspheres still has a excellent ability to induce the induction of hydroxyapatite(HA)in vitro,but when the amount of doping exceeds a certain limit,if the amount of Eu3+ doping reaches 2%mole,its biological activity will be affected,and the formation ability of MBG induced hydroxyapatite is reduced.3.Ce/Eu/MBG microspheres were synthesized by co-doping double rare earth using MBG2 microspheres as carriers.The experimental results showed that the trace rare earth co-doped microspheres still had excellent bioactivity and drug controlled release properties.At the same time,Ce/Eu/MBG microspheres with low concentration(50-200 ug/mL)have no toxicity to osteosarcoma MG-63 cells,and the drug loaded Ce/Eu/MBG-DOX microspheres have a significant inhibitory effect on the MG-63 cells by releasing DOX again.In this paper,the synthesized rare-earth doped mesoporous bioactive glass has non-toxic,excellent biological activity and drug controlled release properties,and the release of DOX has a significant inhibitory effect on osteosarcoma MG-63 cells.Hence,rare earth doped MBG is expected to be an alternative biomaterial in bone tissue repair engineering.