Protein Hydrogels: The Swiss Army Knife for Enhanced Mechanical and Bioactive Properties of Biomaterials - PMC

[Michael Hayes]

Abstract

Biomaterials are dynamic tools with many applications: from the primitive use of bone and wood in the replacement of lost limbs and body parts, to the refined involvement of smart and responsive biomaterials in modern medicine and biomedical sciences. Hydrogels constitute a subtype of biomaterials built from water-swollen polymer networks. Their large water content and soft mechanical properties are highly similar to most biological tissues, making them ideal for tissue engineering and biomedical applications. The mechanical properties of hydrogels and their modulation have attracted a lot of attention from the field of mechanobiology. Protein-based hydrogels are becoming increasingly attractive due to their endless design options and array of functionalities, as well as their responsiveness to stimuli. Furthermore, just like the extracellular matrix, they are inherently viscoelastic in part due to mechanical unfolding/refolding transitions of folded protein domains. This review summarizes different natural and engineered protein hydrogels focusing on different strategies followed to modulate their mechanical properties. Applications of mechanically tunable protein-based hydrogels in drug delivery, tissue engineering and mechanobiology are discussed.

Keywords: hydrogel, protein, mechanical modulation, viscoelasticity, extracellular matrix, folding, single-molecule, nanomechanics

In this review, we present an overview on different protein hydrogels with optimized biological and mechanical properties, and their current applications in basic science and biomedicine. We will review evidence supporting the mechanical design of protein hydrogels based on the nanomechanics of the hydrogel building blocks. In combination with their well-known bioactive properties, protein hydrogels emerge as all-purpose, multifunctional biomaterials, with a versatility that resembles that of a top-of-the-line Swiss army knife. To provide a better perspective on the topic and highlight the advantages of protein hydrogels, we introduce first the wider field of hydrogels. This field is vast, and we apologize for missing relevant references that may have escaped our scrutiny.

https://pmc.ncbi.nlm.nih.gov/articles/PMC8307158/ 

MH] 

Protien-based Biochar is still Biochar. If a protein-based hydrogel can be deployed in isolated oceanic deserts for CDR and SMR needs, retrieved and reduced to Biochar, the process would start at C neutral. Taking the system to C negative status will likely not be overly hard.