Preparation And Properties Of Adhesive Bone Repair Hydrogels Based On Composite And Modified Nano-hydroxyapatite

For diseases such as bone defects or fractures,the traditional method is to perform clinical treatment by implanting bone repair materials(e.g.,implantable medical metal materials,bioceramic materials,etc.).Most bone defects are irregular in shape,and bone repair materials cannot fill the whole bone defect well,and thus cannot form good contact with bone tissue,which affects the healing and regeneration of bone.The most important defect is the poor bonding ability between the bone repair material and the bone tissue interface.Bone adhesive repair materials commonly used in clinical practice,such as polymethyl methacrylate(PMMA)and calcium phosphate(CPC)bone cement,have weak adhesion to the bone tissue interface,but their degradation rate is fast and they are prone to thermal necrosis of bone tissue;although CPC has good biocompatibility and osteoconductivity,this bone adhesive has cytotoxicity,low mechanical strength,poor fixation with bone tissue in the biological environment,and an unpredictable degradation rate.Although CPC has good biocompatibility and osteoconductivity,this bone adhesive has disadvantages such as cytotoxicity,low mechanical strength,poor fixation properties with bone tissue in the biological environment,and uncontrollable degradation rate,resulting in high failure rate of bone repair.In order to solve the problems of such bone repair materials,the search for an adhesive bone repair material that can have good plasticity,osteoconductivity and osteoconductivity with good mechanical properties and degradation rate has become one of the important topics in clinical medicine.The main research of this work is as follows: based on nano hydroxyapatite(HAp),it was compounded and modified,and two composite hydrogels were prepared by physical mixing method,and the properties of nano hydroxyapatite-based composite hydrogels treated with different methods were investigated.The results of the study are as follows:1.SF/TA/HAp/r GO-T composite hydrogel with bone bonding properties was prepared by physically blending tannic acid(TA),silk protein(SF),nanohydroxyapatite(HAp),and reduced graphene oxide(r GO-T)after reduction of tannic acid in a low p H environment.The successful preparation of the raw material and composite hydrogel was demonstrated by the characterization means of infrared spectroscopy,UV-visible spectroscopy and X-ray diffraction spectroscopy;the strong hydrogen bonding between SF and TA and the strong bonding of deprotonated phenolic groups with metal cations between TA and HAp at low p H environment;the good rheological properties,self-healing properties,tensile properties and resistance to wet adhesion properties of the composite hydrogel were demonstrated by the tests of HAp has a synergistic effect with r GO-T,and the mechanical properties and adhesion properties of the composite hydrogel have been improved.2、Amino nano hydroxyapatite(AHAp)was obtained after amination modification of HAp by 3-aminopropyltriethoxysilane(APTES),and OCMC/Gel/AHAp composite hydrogel was formed with oxidized carboxymethyl cellulose(OCMC)and gelatin(Gel)at 37 °C.The characterization of infrared spectra,UV-visible spectra as well as X-ray diffraction spectra and scanning electron microscopy proved the successful preparation of raw materials and composite hydrogels;rheological property tests,self-healing property tests,tensile property tests and adhesion property tests showed that when comparing the unmodified HAp,AHAp and composite hydrogels without any addition of HAp or AHAp,the composite hydrogels with the addition of AHAp,had more The results of rheological tests on gel time showed that the composite hydrogel could be used as an injectable hydrogel and the time was in a reasonable surgical time range.