Biotin-Avidin-Mediated Capture of Microspheres on Polymer Fibers

Abstract

Systems for efficient and selective capture of micro-scale objects and structures have application in many areas and are of particular relevance for selective isolation of mammalian cells. Systems for the latter should also not interfere with the biology of the cells. This study demonstrates the capture of microspheres through orthogonal coupling using biotin (ligand) and (strept)avidin (receptor). Fibrous poly(ethylene terephthalate) (PET) meshes were hydrolyzed under controlled alkaline conditions to obtain activated surfaces with COOH groups allowing for the functionalization of the PET with biotin of various spacer length. The system capture efficiency was optimized by varying the length of spacer presenting the biotin against streptavidin. In a proof of concept experiment, avidin-functionalized microspheres were used as surrogates for cells, and their capture under dynamic conditions including virous mixing and high-flow rate perfusion is demonstrated. Functionalization of PET meshes with biotin conjugated to longest spacer yielded the most efficient capture of microspheres. These preliminary results lay the foundation for the development of biosystems for capture of specific cells under physiologically relevant conditions, using biorthogonal avidin-biotin interactions.

The avidin‐theophylline complex: A structural and computational study

“…For all these reasons, the avidin‐biotin system is constantly used as a versatile module for biochemical and ELISA assays 8,9 and affinity purifications 10 . Few remarkable examples of avidin‐biotin reproposed as tool in biomedicine and bio‐nanotechnology are the delivery of Kv1.3 siRNAs in the treatment of autoimmune disorders 11 or its usage as cargo for cell‐penetrating peptides 12 .…”