Sdf-1 molecularly imprinted biomimetic scaffold as a potential strategy to repair the infarcted myocardium

Background: In situ cardiac tissue engineering aims to heal the infarcted myocardium by guiding tissue regeneration within the patient body. A key step in this approach is the design of a bioactive scaffold, able to stimulate tissue repair at the site of damage. In the development of bioactive scaffolds, molecular imprinting nanotechnology has been recently proposed as a new functionalization strategy. Objectives: In this work, Molecularly Imprinted Particles (MIP) with recognition properties towards the stromal-derived factor-1 (SDF-1) were synthesized, characterized and used for the functionalization of a biomimetic scaffold. MIP are expected to favor the enrichment of the SDF-1 bioactive molecule within the scaffold, thereby promoting myocardial regeneration. Methods: MIP were obtained by precipitation polymerization, using the SDF-1 molecule as a template. Alginate/gelatin/elastin sponges were fabricated by freeze-drying and functionalized by MIP deposition. Morphological, physicochemical and functional analyses were performed both on MIP and on MIP-modified scaffolds. A preliminary biological in vitro investigation was also carried out using rat cardiac progenitor cells (rCPCs). Results: Imprinted nanoparticles with an average diameter between 0.6 and 0.9 µm were obtained. Infrared analysis of MIP confirmed the expected chemical structure. Recognition and selectivity tests showed that MIP were able to selectively recognize and rebind the template, even after their deposition on the scaffold. In vitro biological tests showed that cell adhesion to the scaffold was promoted by MIP functionalization. Conclusion: Results obtained in the present study suggest that biomimetic alginate/gelatin/elastin sponges, functionalized by MIP with recognition properties towards SDF-1, could be successfully used for tissue engineering approaches to repair the infarcted heart.