Terminal-end functionalization of chondroitin sulfate for the synthesis of biomimetic proteoglycans

Chondroitin sulfate (CS) based bottle brush proteoglycan mimetics may be employed to restore tissue functionality. Synthesis of CS bottle brush structures requires immobilization of CS at its terminal end. In this study, we investigated commercially available natural CS for use in CS bottle brush synthesis. A terminal primary amine on CS was identified and utilized to conjugate amine-reactive vinyl monomers (i.e. acrylic acid and allyl glycidyl ether). Conjugation of vinyl monomers to the CS terminal amine was confirmed using a fluorescamine assay, 1H NMR, and ATR-FTIR. CS was also immobilized onto epoxy functionalized surfaces via the CS terminal primary amine as confirmed by contact angle measurements of surface wettability. Attachment of polymeriziable end groups to CS and attachment of CS to functionalized substrates demonstrated here are the first steps towards synthesis of CS bottle brush PG mimics.