An Artificial Phase‐Transitional Underwater Bioglue with Robust and Switchable Adhesion Performance

Versatile Pickering emulsion gel lubricants stabilized by cooperative interfacial graphene oxide-polymer assemblies

Although a large number of water- and oil-based gel lubricants have found extensive potential applications in industrial and biomedical fields, developing new-type emulsion-based gel lubricants that may effectively integrate their characteristics and preponderances remains a significant challenge. Here a water-in-oil Pickering emulsion gel lubricant that is able to combine the high colloidal stability of traditional Pickering emulsions, the good swelling and corrosion resistance of oil-based gel lubricants, and the high cooling capacity of water-based gel lubricants prepared from a binary mixture of aqueous graphene oxide (GO) dispersion and diamino-functionalized polydimethylsiloxane oil solution in a broad concentration, pH, and water volume fraction range is reported. It can provide favourable lubrication for the Si3N4/steel and Si3N4/silicone tribopairs either in air or under water owing to the formation of a sturdy adsorbed oil film and ball-bearing actions of the GO particles. It can also be printed into various colourful 2D and 3D geometries upon direct extrusion into water, thanks to its water-in-oil nature and inherent shear-thinning and thixotropic properties, which further shows good prospects in underwater operations and artificial biomimetic organs. Our study may provide new insights into the design and preparation of novel semi-solid materials for diverse industrial, engineering, and biomedical applications.

Tailored Functionalized Protein Nanocarriers for Cancer Therapy: Recent Developments and Prospects

Recently, the potential use of nanoparticles for the targeted delivery of therapeutic and diagnostic agents has garnered increased interest. Several nanoparticle drug delivery systems have been developed for cancer treatment. Typically, protein-based nanocarriers offer several advantages, including biodegradability and biocompatibility. Using genetic engineering or chemical conjugation approaches, well-known naturally occurring protein nanoparticles can be further prepared, engineered, and functionalized in their self-assembly to meet the demands of clinical production efficiency. Accordingly, promising protein nanoparticles have been developed with outstanding tumor-targeting capabilities, ultimately overcoming multidrug resistance issues, in vivo delivery barriers, and mimicking the tumor microenvironment. Bioinspired by natural nanoparticles, advanced computational techniques have been harnessed for the programmable design of highly homogenous protein nanoparticles, which could open new routes for the rational design of vaccines and drug formulations. The current review aims to present several significant advancements made in protein nanoparticle technology, and their use in cancer therapy. Additionally, tailored construction methods and therapeutic applications of engineered protein-based nanoparticles are discussed.

Molecularly Engineered Protein Glues with Superior Adhesion Performance

Naturally inspired proteins are investigated for the development of bioglues that combine adhesion performance and biocompatibility for biomedical applications. However, engineering such adhesives by rational design of the proteins at the molecular level is rarely reported. Herein, it is shown that a new generation of protein-based glues is generated by supramolecular assembly through de novo designed structural proteins in which arginine triggers robust liquid-liquid phase separation. The encoded arginine moieties significantly strengthen multiple molecular interactions in the complex, leading to ultrastrong adhesion on various surfaces, outperforming many chemically reacted and biomimetic glues. Such adhesive materials enable quick visceral hemostasis in 10 s and outstanding tissue regeneration due to their robust adhesion, good biocompatibility, and superior antibacterial capacity. Remarkably, their minimum inhibitory concentrations are orders of magnitude lower than clinical antibiotics. These advances offer insights into molecular engineering of de novo designed protein glues and outline a general strategy to fabricate mechanically strong protein-based materials for surgical applications.

Biosynthetic Structural Proteins with Super Plasticity, Extraordinary Mechanical Performance, Biodegradability, Biocompatibility and Information Storage Ability

Degradable bioplastics have attracted growing interest worldwide. However, it is challenging to develop bioplastics with a simple processing procedure, strong mechanical performance, good biocompatibility, and adjustable physicochemical properties. Herein, we introduced structural proteins as building blocks and developed a simple environmentally friendly approach to fabricate diverse protein-based plastics. A cost-effective and high-level production approach was developed through batch fermentation of Escherichia coli to produce the biomaterials. These bioplastics possess super plasticity, biocompatibility, biodegradability, and high resistance to organic solvents. Their structural and mechanical properties can be precisely controlled. Besides, high density information storage and hemostatic applications were realized in the bioplastic system. The customizable bioplastics have great potential for applications in numerous fields and are capable to scale up to the industrial level.

Genetically Engineered Polypeptide Adhesive Coacervates for Surgical Applications

Adhesive hydrogels have been developed for wound healing applications. However, their adhesive performance is impaired dramatically due to their high swelling on wet tissues. To tackle this challenge, we fabricated a new type of non-swelling protein adhesive for underwater and in vivo applications. In this soft material, the electrostatic complexation between supercharged polypeptides with oppositely charged surfactants containing 3,4-dihydroxylphenylalanine or azobenzene moieties plays an important role for the formation of ultra-strong adhesive coacervates. Remarkably, the adhesion capability is superior to commercial cyanoacrylate when tested in ambient conditions. Moreover, the adhesion is stronger than other reported protein-based adhesives in underwater environment. The ex vivo and in vivo experiments demonstrate the persistent adhesive performance and outstanding behaviors for wound sealing and healing.

Bioengineered Protein-based Adhesives for Biomedical Applications

Protein-based adhesives with their robust adhesion performance and excellent biocompatibility have been extensively explored over years. In particular, the unique adhesion behaviours of mussel and sandcastle worm inspired the development of synthetic adhesives. However, the chemical synthesized adhesives often demonstrate weak underwater adhesion performance and poor biocompatibility/biodegradability, limiting their further biomedical applications. In sharp contrast, genetically engineering endows the protein-based adhesives the ability to maintain underwater adhesion property as well as biocompatibility/biodegradability. Herein, we outline recent advances in the design and development of protein-based adhesives by genetic engineering. We summarize the fabrication and adhesion performance of elastin-like polypeptide-based adhesives, followed by mussel foot protein (mfp) based adhesives and other sources protein-based adhesives, such as, spider silk spidroin and suckerin. In addition, the biomedical applications of these bioengineered protein-based adhesives are presented. Finally, we give a brief summary and perspective on the future development of bioengineered protein-based adhesives.