Protein Engineering in the Development of Functional Hydrogels

Abstract

Proteins, which are natural heteropolymers, have evolved to exhibit a staggering array of functions and capabilities. As scientists and engineers strive to tackle important challenges in medicine, novel biomaterials continue to be devised, designed, and implemented to help to address critical needs. This review aims to cover the present advances in the use of protein engineering to create new protein and peptide domains that enable the formation of advanced functional hydrogels. Three types of domains are covered in this review: (a) the leucine zipper coiled-coil domains, (b) the EF-hand domains, and (c) the elastin-like polypeptides. In each case, the functionality of these domains is discussed as well as recent advancements in the use of these domains to create novel hydrogel-based biomaterials. As protein engineering is used to both create and improve protein domains, these advances will lead to exciting new biomaterials for use in a variety of applications.

Peptide-Based Polymer Therapeutics

“…Engineering of elastin-like peptides (ELPs) has also been explored for drug delivery. ELPs are 5-1500 amino acids in length based on the pentamer sequence Val-Pro-Gly-X-Gly, where X represents any amino acid [104]. Synthesis is achieved through recombinant DNA techniques (Section 2.1).…”

Visual optical biosensors based on DNA-functionalized polyacrylamide hydrogels

“…graphite, graphene, and carbon nanotubes) [3][4][5], and silica or glass [6], we will focus our discussion on hydrogels. Hydrogels are crosslinked hydrophilic polymer networks that swell in water [7][8][9][10][11][12][13][14][15]. Compared to many other types of materials, immobilization in hydrogels occurs in 3-D, allowing a high loading capacity of sensing molecules.…”

Bioinspired Strategies for Hard Tissue Regeneration

“…Elastin-like polypeptides (ELPs) have the ability to undergo organized self-assembly into network structures through a process of temperature-induced phase separation or coacervation (20) . Elastin-like polypeptides are derived from a repeating motif within a hydrophobic domain of mammalian tropoelastin: the most common motif has the sequence (VPGXG) m , where X can be any amino acid other than proline, and m is the number of repeats (1). There are many other variants of ELPs that range from other pentapeptides with the repeat sequence KGGVG (21) or LGGVG (22) to heptapeptides with the sequence LGAGGAG and nonapeptides with the sequence LGAGGAGVL.…”

“…Protein-engineered biomaterials have recently received much attention. The diversity of peptide modules available throughout the proteome broadens the horizon that protein engineered biomaterials can achieve (1). The current challenges for developing protein-based scaffolds for tissue engineering lies in the fabrication of three-dimensional hierarchical materials that mimic the structural complexity of the natural ECM.…”