Anti-Adhesive Nanosurfaces For Circulating Tumor Cells Capture And Purification

Isolating pure and viable circulating tumor cells(CTCs)from blood is still a challenging task for the following enumeration and molecular analysis because of their rarity and heterogeneity.Here,we developed some ultrasensitive platforms for CTCs isolation based on reasonable molecular design on the surface,to obtain CTCs from blood with high purity and activity.1.A PCBMA hydrogel substrate was fabricated by free radical polymerization to provide a cell-compatible and antifouling interface.Then,chitosan nanofibers were introduced onto the hydrogel substrate to provide a nanostructured surface to improve the capture efficiency.Then,the substrate conjugating with EpCAM antibody achieved high capture efficiency for the isolation of the target CTCs(e.g.,MCF-7)from the mixed cells.2.An EpCAM antibody modified hydrogel nanoparticle substrate was fabricated for capturing CTCs.The hydrogel nanoparticles with a good uniformity were synthesized through a simple reflux precipitation polymerization,and were then modified onto the glass surface.The hydrogel nanoparticles provided the effect of interfacial properties to control non-specific cell adhesion and also build a flexible surface for immobilizing EpCAM antibody to realize CTCs capture with high purification.Finally,1-32 CTCs/mL were detected from 4 cancer patients' blood and none was detected from 5 healthy volunteers.3.We fabricated a thermo-responsive chitosan nanofiber substrate to effectively capture,purify and release the target cancer cells,assisting by PNIPAM brushes and DNA hybridization.The PNIPAM brushes were designed to enable WBCs to detach from aptamer-PNIPAM-chitosan-nanofiber surface during the conformational transition.Meanwhile,these specific captured CTCs were retained at a high purity.Moreover,effective and intact release of CTCs from the substrates without any foreign agents was realized by complementary sequences efficiently hybridizing with aptamers,and the specific cell release made CTCs to further be purified.The present work provides a new strategy in the design of bio-interface for isolating the target CTCs from whole blood samples with high purity.4.A biodegradable hydrogel coating magnetic nanoparticle was developed for efficient capture and gentle release of CTCs from human blood with high viability.SBMA and MAA as monomers,and BACy as a crosslinker,were used to synthesize the hydrogel shell by reflux precipitation polymerization.SBMA was used to decrease non-specific cell adhesion,and MAA integrating into the hydrogel shell provided an active site for the immobilization of EpCAM antibody.Furthermore,biofriendly glutathione(GSH)was used to degrade the hydrogel shell to release the captured CTCs.5.DiI was coated onto the magnetic nanoparticle surface by SiO2 to constitute a fluorescent magnetic nanoparticle that could directly identify CTC cells in blood samples.A bifunctional PCBMA as antifouling molecule was coupled onto the core-shell nanoparticles to decrease non-specific cell adhesion and conjugate with a cocktail of EpCAM and N-cadherin antibodies.Using the synergistic effect of the two antibodies,the magnetic nanoparticle not only can capture CTCs with high EpCAM expression,but also can capture heterogeneous CTCs with low EpCAM expression.The fluorescent-magnetic nanoparticle was fabricated to capture and rapidly identify of epithelial as well as mesenchymal CTCs.