The Effecgt Of Non-peptide Bioactive Macromolecules On Cell Behaviors

The non-peptide bioactive macromolecules have various biological activity andbiological functionalitites, such as the genetic information transfer, embryosdifferentiation control, and growth and development promotion. The non-peptidebioactive macromolecules are divided into two types: nucleic acids andpolysaccharides. Nucleic acids includes DNA, RNA and aptamer (APT). DNA, RNAcan transfect into cells through the way of gene transfection, and its expression canregulate the cell behavior; APT is a nucleic acid form antibody, it can combinewithmaterials in nanoscale, mark or enrich cancer cells, applied in the biomedical fieldthrough the effect of the specific recognition of target cells. The other kind ofnon-peptide active macromolecular polysaccharide has many biological functionalities,they are involved in cell recognition and identification of cells and biomolecules.Particularly, the sulfated polysaccharides can regulate various growth factors andcytokines activity, and further the differentiation of stem cells. Research shows that thesulfated polysaccharide heparin can regulate embryonic stem cell pluripotency anddirected differentiation well, but due to the complex structure of heparins, they showdifferent bioactivities from different sources. Meanwhile, sulfated chitosan, with thesimple structure and effect of heparin analogoes, can be prepared using the chitosan viasulfonation. The sulfated chitosan can also regulate cell behavior, and promote thedifferentiation of stem cells.We selected aptamer (APT) and polysaccharide to study their effects on cellbehaviors. By investigating the cancer cell’s enrichment and the differentiation of stemcells, we did some basic research on the early cancer detection and stem cells’application in the biomedical field. Our research is mainly divided into two parts: the specific adhesion of blood cancer cells on the APT modified surface; the effect ofsulfated-chitosan on the differentiation of mouse embryonic stem cells (mES).1, For potential applications in the isolation and enrichment of circulating tumorcells (CTCs) on the serum environment, we have developed gold nanoparticle layers(GNPLs) of different roughnesses modified with poly(oligo(ethylene glycol)methacrylate)(POEGMA) as an antifouling spacer (GNPL-POEGMA), and furthermodified with the TD05aptamers which can bind to specific cancer cell (Ramos cell).In serum-containing environment, GNPL-POEGMA-APT showed an enhancedselectivity for Ramos cells from cell mixtures, which increased with increasing surfaceroughness. The density of Ramos cells adherent to highly roughGNPL3-POEGMA-APT was6.6times that of CEM cells; the cells on theGNPL-POEGMA-APT surface still had good cell activity, and theGNPL-POEGMA-APT surface had good capture efficiency to the Ramos cell; under4℃, the GNPLPOEGMA-APT increased the capture efficiency to the Ramos cells.The results of this study indicate that surfaces combining appropriate chemicalcomposition and micro/nano roughness structures may be useful for cell separation,including the isolation of cancer cells for diagnosis.2, the heparin with certain structures can regulate the neural differentiation ofmouse embryonic stem cells, but the structure of heparin was complex and can’t becontrolled. While the site and degree of sulfonation of heparin analogues-sulfatedchitosan can be simply controlled by chemical modification. It was discovered thatsulfated chitosan with certain sulfated site can realize the specific adsorption of certainproteins. To verify whether the sulfated chitosan has the role of heparin, weinvestigated the effect of sulfated chitosan on the differentiation of mouse embryonicstem cells (mES). We found that adding sulfated chitosan with different sulfation sitesinto the cell culture media favored the neural differentiation of mESCs, especially6-O-sulfated chitosan. In this study, the mESCs we used can synthesize heparinthemselves. Thus, in order to better determine the role of sulfated chitosan on mESCdifferentiation, we added sodium chlorate into the cell culture media to inhibit the heparin synthesis process of mESCs. It was found that the6S sulfated chitosan wasmost conducive to neural differentiation of mESCs, similar to heparin; besides, whenthe sulfated degree was0.83~0.81,6S can better promote the neural differentiation ofmESCs. Our research indicated the potential of sulfated chitosan for qualitativedifferentiation of embryonic stem cells, which can be applied for the differentiation ofembryonic stem cells and biomedicine.Our study shows that we can realize the specific adhesion of blood cancer cellsand the differentiation of ESCs by regulating cell behaviors with non-peptide bioactivemolecules: cancer cells can specific adhere to aptamer functionalized micro/nanosurface;6S with a specific sulfated degree can promote the neural differentiation ofmESCs. We can see that non-peptide bioactive macromolecules undoubtedly havegreat potential for applications in cancer cell enrichment, cancer diagnosis andbiomedicine.