Construction of a multi-functional extracellular matrix protein that increases number of N1E-115 neuroblast cells having neurites

Recombinant Structural Proteins and Their Use in Future Materials

Recombinant proteins are polymers that offer the materials engineer absolute control over chain length and composition: key attributes required for design of advanced polymeric materials. Through this control, these polymers can be encoded to contain information that enables them to respond as the environment changes. However, despite their promise, protein-based materials are under-represented in materials science. In this chapter we investigate why this is and describe recent efforts to address this. We discuss constraints limiting rational design of structural proteins for advanced materials; advantages and disadvantages of different recombinant expression platforms; and, methods to fabricate proteins into solid-state materials. Finally, we describe the silk proteins used in our laboratory as templates for information-containing polymers.

Construction of a tissue-specific transcription factor-tethered extracellular matrix protein via coiled-coil helix formation

Tissue-specific transcription factor Olig2 was tethered to a designed artificial extracellular matrix proteinviacoiled-coil helix formation.

Designing ECM-mimetic materials using protein engineering

The natural extracellular matrix (ECM), with its multitude of evolved cell-instructive and cell-responsive properties, provides inspiration and guidelines for the design of engineered biomaterials. One strategy to create ECM-mimetic materials is the modular design of protein-based engineered ECM (eECM) scaffolds. This modular design strategy involves combining multiple protein domains with different functionalities into a single, modular polymer sequence, resulting in a multifunctional matrix with independent tunability of the individual domain functions. These eECMs often enable decoupled control over multiple material properties for fundamental studies of cell-matrix interactions. In addition, since the eECMs are frequently composed entirely of bioresorbable amino acids, these matrices have immense clinical potential for a variety of regenerative medicine applications. This brief review demonstrates how fundamental knowledge gained from structure-function studies of native proteins can be exploited in the design of novel protein-engineered biomaterials. While the field of protein-engineered biomaterials has existed for over 20years, the community is only now beginning to fully explore the diversity of functional peptide modules that can be incorporated into these materials. We have chosen to highlight recent examples that either (i) demonstrate exemplary use as matrices with cell-instructive and cell-responsive properties or (ii) demonstrate outstanding creativity in terms of novel molecular-level design and macro-level functionality.

Multifunctional materials through modular protein engineering

The diversity of potential applications for protein-engineered materials has undergone profound recent expansion through a rapid increase in the library of domains that have been utilized in these materials. Historically, protein-engineered biomaterials have been generated from a handful of peptides that were selected and exploited for their naturally evolved functionalities. In recent years, the scope of the field has drastically expanded to include peptide domains that were designed through computational modeling, identified through high-throughput screening, or repurposed from wild type domains to perform functions distinct from their primary native applications. The strategy of exploiting a diverse library of peptide domains to design modular block copolymers enables the synthesis of multifunctional protein-engineered materials with a range of customizable properties and activities. As the diversity of peptide domains utilized in modular protein engineering continues to expand, a tremendous and ever-growing combinatorial expanse of material functionalities will result.

Biomatrices and biomaterials for future developments of bioprinting and biofabrication

The next step beyond conventional scaffold-based tissue engineering is cell-based direct biofabrication techniques. In industrial processes, various three-dimensional (3D) prototype models have been fabricated using several different rapid prototyping methods, such as stereo-lithography, 3D printing and laser sintering, as well as others, in which a variety of chemical materials are utilized. However, with direct cell-based biofabrication, only biocompatible materials can be used, and the manufacturing process must be performed under biocompatible and physiological conditions. We have developed a direct 3D cell printing system using inkjet and gelation techniques with inkjet droplets, and found that it had good potential to construct 3D structures with multiple types of cells. With this system, we have used alginate and fibrin hydrogel materials, each of which has advantages and disadvantages. Herein, we discuss the roles of hydrogel for biofabrication and show that further developments in biofabrication technology with biomatrices will play a major part, as will developments in manufacturing technology. It is important to explore suitable biomatrices as the next key step in biofabrication techniques.