Cabanas - A fluorogenic monolayer to detect the co-immobilization of peptides that combine cartilage targeting and regeneration†

Jordi Cabanas-Danes, Carlo Nicosia, Ellie Landman, Marcel Karperien, Jurriaan Huskens and Pascal Jonkheijm

Journal of Materials Chemistry B - 2013

Abstract

Strategies to generate platforms combining tissue targeting and regeneration properties are in great
demand in the regenerative medicine field. Here we employ an approach to directly visualize the
immobilization of cysteine-terminated peptides on a novel fluorogenic surface. Peptides with relevant
biological properties, CLPLGNSH and CLRGRYW, were synthesized to function as peptide binders to
transforming growth factor (TGF)-b1 and collagen type II (CII). The selective immobilization of the
peptides was directly detected using a fluorogenic surface. Adhered proteins were confined to patterns
of these peptides matching with the fluorogenic areas. These results show that the fluorogenic signal
can be used to detect the chemo-selective immobilization of non-fluorescent biomolecules and to
correlate the cell response with the patterned peptides. After analyzing the sequence specificity and
cross-reactivity of the binding of TGF-b1 and CII to the respective peptide regions employing
immunofluorescence assays, both peptides were co-immobilized in a step-wise process as detected by
the fluorogenic surface. TGF-b1 and CII could be self-sorted from a mixture in a regio-selective manner
resulting in a bi-functional protein platform. Surfaces of CLPLGNSH pre-loaded with TGF-b1 showed
excellent bioactivity in combination with human articular chondrocytes (HACs) and stimulated
expression of chondrogenic markers.