Vision for Functionally Decorated and Molecularly Imprinted Polymers in Regenerative Engineering

Abstract

The emerging field of regenerative engineering offers a great challenge and an even greater opportunity for materials scientists and engineers. How can we develop materials that are highly porous to permit cellular infiltration, yet possess sufficient mechanical integrity to mimic native tissues? How can we retain and deliver bioactive molecules to drive cell organization, proliferation, and differentiation in a predictable manner? In the following perspective, we highlight recent studies that have demonstrated the vital importance of each of these questions, as well as many others pertaining to scaffold development. We posit hybrid materials synthesized by molecular decoration and molecular imprinting as intelligent biomaterials for regenerative engineering applications. These materials have potential to present cell adhesion molecules and soluble growth factors with fine-tuned spatial and temporal control, in response to both cell-driven and external triggers. Future studies in this area will address a pertinent clinical need, expand the existing repertoire of medical materials, and improve the field's understanding of how cells and materials respond to one another.

Keywords: Bioconjugation; Drug delivery; Intelligent biomaterials; Molecular imprinting; Regenerative engineering.

Fig. 1

Intelligent biomaterial scaffolds must present growth factors and other molecules in a rational spatiotemporal manner, possess an appropriate modulus, and degrade with predictable and controlled kinetics in order to facilitate the specific cell functions of diverse co-cultures for regenerative engineering

Fig. 2

Scaffolds for regenerative engineering applications can be loaded with multiple bioactive factors and tailored to deliver these factors sequentially with fine-tuned spatiotemporal control. Adapted from Lee et al. [2]

Fig. 3

Influence of material alignment and topography on cell arrangement and morphology. a Materials with aligned structures can result in the alignment of cells, whereas b randomly oriented materials may result in the random arrangement of cells. c Rough surfaces may lead to round cell morphologies, compared to d flat surfaces which can increase cell spreading

Fig. 4

Carbodiimide-mediated coupling reactions can functionalize the carboxylic acid moieties of alginate, at ambient conditions, with aminecontaining natural or synthetic ligands

Fig. 5

Proteins, peptide epitopes, or cells (not shown) can serve as templates for molecularly imprinted polymerizations. Following polymerization and purification, chemical modification of pendant functional moieties, as described previously, can generate complex material structures