Glutaraldehyde(GA),the most widely used crosslinking agent for biomaterials,is cytotoxic.CaCl2 is of particular interest due to its non-toxic nature.Rhein can chelate Ca2+and promote bone growth.Here we reported a novel nano calcium-deficient hydroxyapatite/O-carboxymethyl chitosan-CaCl2 microspheres loaded with rhein(RH-nCDHA/OCMC-CaCl2 microspheres)using CaCl2 as crosslinking agent for bone defect repair.The obtained microspheres were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),thermogravimetric analysis(TG)and Fourier transform infrared spectroscopy(FT-IR).The surface of the obtained microspheres is rough with quite a few voids.The nano calcium-deficient hydroxyapatite(nCDHA)accounts for about 70％of the total weight of the microspheres,which is equivalent to the proportion of inorganic substances in human bones.A high encapsulation efficiency(EE)and loading capacity(LC)of the microspheres loaded with rhein was 90.20±0.60％and 11.03±0.30％,respectively.For microspheres using CaCl2 in simulated body fluid(SBF)after 14 days,the drug released continuously and bone-like apatite formed like layer.The cells on the surface of the RH-nCDHA/OCMC-CaCl2 microspheres grew better comparing with nCDHA/OCMC-GA microspheres and the skull defects of rats after landfill can be almost repaired after 8 weeks,which revealed the potential of the microspheres for bone repair.

Zhenzhen Tian;Yuanyuan Guo;Xiuying Yang;Kebing Guo;Jingou Ji;Shilei Hao

School of Chemistry and Chemical Engineering,Chongqing University,No.55,University City South Road,Shapingba District,Chongqing 401331,China;Guizhou KingMed Center for Clinical Laboratory Co.,Ltd,Guizhou 550001,China;Key Laboratory of Biorheological Science and Technology,Ministry of Education,College of Bioengineering,Chongqing University,Chongqing 400030,China

仿生工程学报（英文版）

[1]Zhenzhen Tian;Yuanyuan Guo;Xiuying Yang;Kebing Guo;Jingou Ji;Shilei Hao-.Nano Calcium-Deficient Hydroxyapatite/O-carboxymethyl Chitosan-CaCl2 Microspheres Loaded with Rhein for Bone Defect Repair)[J].仿生工程学报（英文版）,2022(04):1087-1099

Glutaraldehyde,nCDHA

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