Application Of Micro/Nano Structure And Nanomaterials In Tumor Detection And Cardiomyocyte Differentiation

Tumor and myocardial infarction(MI) have always been the two kinds of diseases with high mortality. However, the most important reason of resulting in death of patients with tumor is the metastasis and recurrence of tumor. Circulating tumor cells(CTCs) are cancer cells which break away from the solid tumor and circulate into the peripheral blood as the cellular origin of metastasis. In early stage of tumor disease, the concentration of CTCs in the body of patients is highly low, therefore, it is of importance to develop methods with high sensitivity of detection CTCs.Cardiomyocytes(CMs) is myocardial cells obtained in terminal differentiation. The heart is hard to restore its normal function after apoptosis of CMs due to MI or other reasons. But the myocardial tissue engineering provides the heart and related diseases a new method. Currently, the research of differentiation of CMs via stem cells to acquire functional myocardial tissue has been widely attention by researchers.We can combine micro-nano structure and nano materials with the technology of biosensor as they are developing rapidly in recent years. This approach can not only promote the performance of biosensor to a new level, but can also further broaden the application fields of biosensor. Moreover, it’s very meaningful to use biodegradable nanostructure as scaffolds in the field of myocardial tissue engineering. According to this, main contents and conclusions of this study are listed as follows:1. Two kinds of microchips with liner micro columns were prepared successfully via the fabrication technology of micro/nano structure, then we combined them with functionalized nanomaterials and nanoscale electrospun which possess similar dimention with the surface components of CTCs respectively to construct cell biosensors for detection of CTCs. Evidence of fluorescence images captured by Inverted Optical Microscope were shown that microchips with columns possessed higher capture efficiency of CTCs compared to the other substrates. Interactions between CTCs and microchips were improved to an extent due to the existence of graphene oxide, functionalized nano-probe and electrospun which also lead to the improvement of sensitivity of detection. This kind of biosensor based on micro/nano structure and functionalized nanomaterials has huge potential application value in clinical analysis for diagnosis of patients with tumor.2. Polylactic-co-glycolic acid(PLGA) which is biodegradable material was used to prepare nanoscale fibers to seed CMs that were obtained by directed differentiation from human induced pluripotent stem cells and form myocardial tissue. SEM images showed that the diameter and density distribution of PLGA nanofibers was good. Immunofluorescence staining and gel electrophoresis results revealed that hiPSC kept its pluripotency. Confocal laser microscopy(CLSM) and quantitative polymerase chain reaction(qPCR) were respectively used to identify the expression of specific proteins and genes in CMs. Results of electrophysiological properties showed that beating frequency of CMs was close to normal heart. All these results illustrated that we got the CMs through directed differentiation and acquired cardiac patch on the nanofibers successfully. We believe that the functionalized myocardial tissue obtained on electrospun substrate will provide a new method for treatment of myocardial related diseases in clinical application.