Monitor The Adsorption Behavior Of Biomolecule On The Material Surface Using By QCM-D

After biomaterial implanted in the human body, the interface interaction is the first and key process between the implanted material and life tissue. Understanding the mechanism of interface interaction between biomaterial and life tissue is an important problem in the field of biomaterial field which can provide useful information to control the interactions and reduce the side-effects of biomaterial application. At present although there are some progresses in the interaction between biomaterial and life tissue. Most of these studies focus on static and macro level and the molecular mechanism of the interaction is still unclear. The in-situ and on-time information of interaction are also difficult to observe. Therefore, based on the previous researches, we use quartz crystal micro balances (QCM-D) to dynamically study the interface interaction between biological molecules (lipid, plasma protein, platelet and cell) and biomaterial in real time.Firstly, we use the QCM-D study the supported lipid bilayer (POPC) self-assembly process and it’s interaction with cells. Results show that through the analysis of the△D/△F curve changes of QCM-D, we can observe the morphological changes of adhesion cells in the material.surface. POPC prevent cell adhesion to some extent, and the adhesion can be improved by functionalization with RGD peptides, which can provide anchorage site for cell adhesion. With the presence of POPC, cells on POPC-RGD will take long time to rearrange their cytoskeleton and remodel extracellular cell matrix (ECM), which led to incompletly spread compared with SiO2. In further research, specific inducible factors can be coupled to the structure of POPC-RGD to study the directional differentiation of BMSCs by using a QCM-D.Secondly, QCM-D was utilized to study the interaction between biomaterials and blood key proteins or platelets. It is indicated that the adsorption and conformational change of fibrinogen on biomaterials can be dynamically detected by using a QCM-D in real-time. And the adsorption capacity of fibrinogen has a relation to its conformation. When the fibrinogens adsorbed on the biomaterials with side-on conformations, the functional sites, which activate the platelets, were unable exposed and led to a good hemocompatibility. Factor XII was more likely absorbed and activated on the materials with negative charges surfaces. The whole blood experiments indicated that fibrinogen played a key role in regulating the coagulation behavior.Thirdly, QCM-D was utilized to study the cells capture on biomaterials. The results showed that the QCM-D is a very effective tool in the study of interactions between cells and biomaterials. It can dynamically detected cells adhesion, spreading, and morphological changes on the biomaterials in situ and in real-time. The results showed that more endothelial progenitor cells (EPCs) adhered on the DOPA+CD133surfaces than on DOPA surfaces and blanks. However, the spreading area of EPCs on the DOPA surfaces was larger than any others. We think that the more proteins on DOPA surfaces may improve the cells spreading.