Successful materials design for bone-tissue engineering requires an understanding of the composition and structure of native bone tissue, as well as appropriate selection of biomimetic natural or tunable synthetic materials (biomaterials), such as polymers, bioceramics, metals and composites. Scalable fabrication technologies that enable control over construct architecture at multiple length scales, including three-dimensional printing and electric-field-assisted techniques, can then be employed to process these biomaterials into suitable forms for bone-tissue engineering. In this Review, we provide an overview of materials-design considerations for bone-tissue-engineering applications in both disease modelling and treatment of injuries and disease in humans. We outline the materials-design pathway from implementation strategy through selection of materials and fabrication methods to evaluation. Finally, we discuss unmet needs and current challenges in the development of ideal materials for bone-tissue regeneration and highlight emerging strategies in the field. Design of bone-tissue-engineering materials involves consideration of multiple, often conflicting, requirements. This Review discusses these considerations and highlights scalable technologies that can fabricate natural and synthetic biomaterials (polymers, bioceramics, metals and composites) into forms suitable for bone-tissue-engineering applications in human therapies and disease models.

Materials design for bone-tissue engineering

Self-assembled peptide and protein amyloid nanostructures have traditionally been considered only as pathological aggregates implicated in human neurodegenerative diseases. In more recent times, these nanostructures have found interesting applications as advanced materials in biomedicine, tissue engineering, renewable energy, environmental science, nanotechnology and material science, to name only a few fields. In all these applications, the final function depends on: (i) the specific mechanisms of protein aggregation, (ii) the hierarchical structure of the protein and peptide amyloids from the atomistic to mesoscopic length scales and (iii) the physical properties of the amyloids in the context of their surrounding environment (biological or artificial). In this review, we will discuss recent progress made in the field of functional and artificial amyloids and highlight connections between protein/peptide folding, unfolding and aggregation mechanisms, with the resulting amyloid structure and functionality. We also highlight current advances in the design and synthesis of amyloid-based biological and functional materials and identify new potential fields in which amyloid-based structures promise new breakthroughs.

/pdf/self-assembling-peptide-and-protein-amyloids-from-structure-3a2o3zyuoj.pdf

Self-assembling peptide and protein amyloids: from structure to tailored function in nanotechnology

Biological materials have robust hierarchical structures capable of specialized functions and the incorporation of natural biologically active components, which have been finely tuned through millions of years of evolution. These highly efficient architectural designs afford remarkable transport and mechanical properties, which render them attractive candidates for flexible electronic sensing technologies. This review provides a comprehensive overview of the fundamental aspects and applications of biological materials for flexible electronic devices and discusses various classes of biological materials by describing their unique structures and functions. We discuss the effect of the biological activity of biological materials on the improved properties in detail, because this effect overcomes the limited bioavailability and restricted morphology of materials generally encountered in traditional flexible electronic devices. We also summarize various approaches for the design and functionalization of natural materials and their applications in flexible electronic devices for use in biomedical, electron, energy, environmental and optical fields. Finally, we provide new insights and perspectives to further describe trends for future generations of biological materials, which are likely to be critical components (building blocks or elements) in future flexible electronics.

New insights and perspectives into biological materials for flexible electronics

Antibacterial coatings that eliminate initial bacterial attachment and prevent subsequent biofilm formation are essential in a number of applications, especially implanted medical devices. Although various approaches, including bacteria-repelling and bacteria-killing mechanisms, have been developed, none of them have been entirely successful due to their inherent drawbacks. In recent years, antibacterial coatings that are responsive to the bacterial microenvironment, that possess two or more killing mechanisms, or that have triggered-cleaning capability have emerged as promising solutions for bacterial infection and contamination problems. This review focuses on recent progress on three types of such responsive and synergistic antibacterial coatings, including i) self-defensive antibacterial coatings, which can "turn on" biocidal activity in response to a bacteria-containing microenvironment; ii) synergistic antibacterial coatings, which possess two or more killing mechanisms that interact synergistically to reinforce each other; and iii) smart "kill-and-release" antibacterial coatings, which can switch functionality between bacteria killing and bacteria releasing under a proper stimulus. The design principles and potential applications of these coatings are discussed and a brief perspective on remaining challenges and future research directions is presented.

Responsive and Synergistic Antibacterial Coatings: Fighting against Bacteria in a Smart and Effective Way.

Surface interaction at the biomaterial–cell interface is essential for a variety of cellular functions, such as adhesion, proliferation, and differentiation. Nevertheless, changes in the biointerface enable to trigger specific cell signaling and result in different cellular responses. In order to manufacture biomaterials with higher functionality, biomaterials containing immobilized bioactive ligands have been widely introduced and employed for tissue engineering and regenerative medicine applications. Moreover, a number of physical and chemical strategies have been used to improve the functionality of biomaterials and specifically at the material interface. Here, the interactions between materials and cells at the interface levels are described. Then, the importance of surface properties in cell function is discussed and recent methods for surface modifications are systematically highlighted. Additionally, the impact of bulk material properties on the cellular responses is briefly reviewed.

https://www.onlinelibrary.wiley.com/doi/epdf/10.1002/admi.201900572

Controlling Cell Behavior through the Design of Biomaterial Surfaces: A Focus on Surface Modification Techniques

2D nanofilms assembled by pure protein with a macroscopic area and multiple functions can be directly formed at the air/water interface or at the solid surface at a timescale of several minutes. The multifunctionality of the nanofilm coating is demonstrated by both top-down and bottom-up micro-/nanoscale interfacial engineering, including surface modification, all-water-based photo/electron-beam lithography, and electroless deposition.

2D Protein Supramolecular Nanofilm with Exceptionally Large Area and Emergent Functions.

A proteinaceous superhydrophobic material for facile protein crystallization is reported. The lysozyme phase transition is rationally manipulated to form a reliable superhydrophobic coating on virtually arbitrary material surfaces with good thermostability and mechanical robustness. Such a surface exhibits a fascinating capability to drive protein crystallization, and the protein crystal array can be facilitated in a large area at an ultralow protein concentration.

A Superhydrophobic Surface Templated by Protein Self-Assembly and Emerging Application toward Protein Crystallization.

Phase‐Transited Lysozyme as a Universal Route to Bioactive Hydroxyapatite Crystalline Film

The invention discloses a method for preparing a biological protein two-dimensional nano-film by using lysozyme. According to the method, nano-particles which are generated by phase transformation reaction of lysozyme molecules and tris (2-carboxyethyl) phosphine hydrochloride are self-assembled on a gas-liquid interface through surface and interface induction to form a biological protein two-dimensional nano-film, or a base material is in contact with the surface of solution in a preparation process of the film, and the nano-particles which are generated by phase transformation of the lysozyme are directly self-assembled on a liquid-solid surface through surface and interface induction to form the two-dimensional nano-film, namely, the nano-particles grow on the surface of the base material in an in-situ manner. The preparation method is simple and environment-friendly; the thickness of the prepared biological protein two-dimensional nano-film is about 30-80 nanometers, surface roughness is small, transparency is high, adhesivity is good, and the method can be used for modifying surfaces of base materials.

Yuan Ha

Papers

2D Protein Supramolecular Nanofilm with Exceptionally Large Area and Emergent Functions.

A Superhydrophobic Surface Templated by Protein Self-Assembly and Emerging Application toward Protein Crystallization.

Phase‐Transited Lysozyme as a Universal Route to Bioactive Hydroxyapatite Crystalline Film

Biological protein two-dimensional nano-film prepared by using lysozyme and preparation method of biological protein two-dimensional nano-film

Nanofilms: 2D Protein Supramolecular Nanofilm with Exceptionally Large Area and Emergent Functions (Adv. Mater. 34/2016)