2022 2nd International Conference on Optical Imaging and Measurement (ICOIM 2022)
Prof. Kaige Wang

BIOGRAPHY:In 2002, He received the PhD degree in science from the Xi’an Institute of optics and precision mechanics of Chinese Academy of Sciences. 1991, got the bachelor degree from the Department of Physics, Northwest University. He had studied and worked as a postdoctoral researcher in the Institute of Physics of CAS, the Anhui Institute of Optics and Mechanics of CAS and Shenzhen University, and as a senior visiting scholar at the University of South Carolina USA.

At present, he is mainly engaged in nano-biophotonics, laser micro-nano-manufacturing, far-field optical super-resolution imaging, single molecule spectroscopy, physical-electronics, micro-current measurement technology, micro-nano-channel fluidics and Lab-on-a-chip, etc., and integrating these technologies to develop devices for investigating the interaction between molecules, especially, biomolecules and medicine molecules at single molecular level, furthermore elucidating the characteristics and mechanism. Recently, he prepared a novel composite nanostructure based on the nanoporous anodic alumina substrate combined with self-organization method, which can be used as an effective solid substrate for SERS to study the characteristics of biological single molecules.

He is the director of the Shaanxi Provincial Key Laboratory of Optoelectronics Technology, the vice director of the National International Joint Research Center for Optoelectronic Technology and Nano-functional Materials; the "Leading Talents of Science and Technology Innovation", and the director of "Innovation Team of Optoelectronics and Nanophotonic Technology and their Biomedical Application" in Shaanxi Province. He is a member of the Standing Committee of the Biomedical Photonics Committee of the Optical Society of China, and a vice-chairman of the Shaanxi Optical Society.

Title: Interaction between DNA and drug molecules at the single molecule level studied with Raman spectroscopy and its imaging technology

Abstract: One of the effective ways to prevent and treat cancer is to make DNA molecules as drug targets. Studying the interaction sites and process of action between anti-cancer drugs and DNA molecules is of great significance for elucidating the anti-cancer activity and drug toxicity mechanism, guiding of taking reasonable medicine, and developing low-toxic and efficient anti-cancer drugs. A fast, label-free, non-destructive, and highly specific optical detection method is also very important. The number, intensity, shape and displacement of the bands involved in Raman spectroscopy depend on the vibration and rotation in the molecular structure of the sample, namely, the Raman spectra reflect the structural information of the sample molecules, and the change of the Raman spectra characteristics is related to the information of the interaction between the molecules. This report briefly introduces the effects and acting mechanisms of several typical anticancer drug molecules on calf thymus DNA molecules and osteosarcoma cells studied with the Laser confocal Raman spectroscopy, surface-enhanced Raman spectroscopy (SERS), and confocal Raman spectroscopy imaging (CRMI) technology.

Based on the Laser confocal Raman spectroscopy, the interaction between Doxorubicin(DOX)and ctDNA has been systemically investigated. It was found that DOX can interact with the four bases and the phosphate of DNA. The interaction between DOX and DNA molecules is a dynamic process, and there are two modes of action, DOX and DNA act to form DOX-DNA complexes while DOX and DOX act to form multimers, the former compresses DNA molecules, and the latter decompresses the DNA molecules. Furthermore, a sort of novel effective solid substrate (NanoPAA-ZnCl2-AuLs) was prepared, and its SERS performance was evaluated by Rhodamine 6G as a probe molecule, the minimum concentration detection limit was 10 -11 M, and enhancement factor was 9.18 × 10 7. The substrate has good SERS performance with high sensitivity and good repeatability and stability. Based on this new solid substrate, the compaction and de-compaction of ctDNA molecules induced by the CTAB/SDS surfactant molecules were investigated in detail, the CTAB causes the compaction of DNA while SDS induces the de-compaction of ctDNA-CTAB complex.

In addition, Osteosarcoma is a common and fatal malignant bone tumor in adolescents that is prone to recurrence and metastasis. The chemotherapeutic drugs gamma secretase inhibitors (DAPT) and cisplatin can inhibit the development of osteosarcoma, but their molecular mechanisms of action for the treatment of tumors have not been elucidated. With the CRMI technique and multivariate data analysis method, the dynamic reaction process of osteosarcoma cells under the action of DAPT and its combination with cisplatin was studied by means of spectrum (molecular "fingerprint" spectrum) and graph (Raman spectrum image), and the synergistic anti-tumor mechanism of DAPT targeting Notch signal pathway and its combination with cisplatin on osteosarcoma cells was expounded. There are two main ways to induce apoptosis by DAPT combined with cisplatin. One is that DAPT combined with cisplatin acts on DNA, and cisplatin reacts with N7 reaction center on purine residue to form a cross-linked complex, which causes the double helix structure of DNA to change, resulting in fragmentation and apoptosis. Second, it causes cytochrome C to be released from mitochondria, activates caspase-3 and other factors, and promotes cell apoptosis.