Colloidal Silica Nanoparticle Surface Coating for Increased Protein Adhesion and Cell Capture in Flow-Based Microtubes

Bryce Allio, Biomedical Engineering, University of Rochester, Rochester, NY 14627, David G. Foster, Chemical Engineering, University of Rochester, Rochester, NY 14627, and Michael R. King, Biomedical & Chemical Engineering, University of Rochester, Goergen Hall, Rochester, NY 14627.

Nanotechnology is becoming increasingly focused at the intersection of material science and cellular biology. Recently, we demonstrated a flow-based selectin-dependent method for the capture and enrichment of specific types of cells (CD34+ hematopoetic stem and progenitor cells and Human Leukemia HL60) from peripheral blood. However these devices depend on a monolayer of selectin protein which has been shown to have a maximum binding efficiency as a function of surface area. We have designed a novel surface coating of colloidal silica nano-particles (average particle Dia. 12nm, 30 % by weight SiO2 ) adhered using an organic titanate resinous coating. Using Alexa Fluor 555 conjugated BSA we have shown an increased protein adhesion of 626.85% when compared to control. During profusion experiments using P-selectin coated microtubes we have observed equivalent cell capture and greatly decreased rolling velocity at equivalent protein concentration compared to control. Our results suggest that this coating may become an advantageous enhancement to existing cell capture implantable devices that have a variety of therapeutic and scientific uses.