Simple and efficient strategy to synthesize PEG‐aldehyde derivatives for hydrazone orthogonal chemistry

Abstract

To satisfy the increasing need for improved tissue substitutes, tissue engineering seeks to create synthetic, three‐dimensional scaffolds made from polymeric materials that can carry and release cells and growth factors to induce new tissue formation. Materials science, in conjunction with biotechnology, can satisfy these needs by developing artificial, synthetic substitutes and organ implants. Here, scaffold ability to promote cell growth and differentiation is a key point and, in this framework, orthogonal chemistry has led the field of biomaterial science into a new area of selective, versatile and biocompatible nature. In particular, hydrazone bond seems to be extremely promising because of its high cytocompatibility, biocompatibility and non‐toxic degradation products. Hydrazone bond formation needs the presence of an aldehyde derivative that sometimes is not very simple to synthesize. Polyethylene glycol (PEG) commonly used in nanoparticles, hydrogels and scaffold production presents several problems, and all the classic synthetic routes are not able to attack the hydroxyl groups present at the extremities of polymer chain. Here we present a simple and efficient strategy to overcome these limitations and synthesize PEG‐aldehyde then useful for hydrazone bonding. Different PEG (2000 and 8000 Da) and methoxy‐PEG (5000 Da) were used, and final products were characterized with NMR and FT‐IR to verify their ability to create hydrazone bonds. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.