Plug-and-Play Biointerfaces: Harnessing Host-Guest Interactions for Fabrication of Functional Polymeric Coatings

Polymeric surface coatings capable of effectively integrating desired functional molecules and ligands are attractive for fabricating bio-interfaces necessary for various applications. Herein, we report the design of a polymeric platform amenable to such modifications in a modular fashion through host-guest chemistry. Copolymers containing adamantane (Ada) moieties, diethylene glycol (DEG) units, and silyloxy groups to provide functionalization handles, anti-biofouling character, and surface attachment, respectively, were synthesized. These copolymers were employed to modify silicon/glass surfaces to enable their functionalization using beta-cyclodextrin (βCD) containing functional molecules and bioactive ligands. Moreover, surface functionalization could be spatially controlled using a well-established technique like microcontact printing. Efficient and robust functionalization of polymer-coated surfaces was demonstrated by immobilizing a βCD-conjugated fluorescent rhodamine dye through the specific noncovalent binding between Ada and βCD units. Furthermore, biotin, mannose, and cell adhesive peptide-modified βCD were immobilized onto the Ada-containing polymer-coated surfaces to direct noncovalent conjugation of streptavidin, concanavalin A (ConA), and fibroblast cells, respectively. It was demonstrated that the mannose-functionalized coating could selectively bind to the target lectin ConA, and the interface could be regenerated and reused several times. Moreover, the polymeric coating was adaptable for cell attachment and proliferation upon noncovalent modification with cell-adhesive peptides. One can envision that the facile synthesis of the Ada-based copolymers, mild conditions for coating surfaces, and their effective transformation to various functional interfaces in a modular fashion offers an attractive approach to engineering functional interfaces for several biomedical applications.