Replace and repair: Biomimetic bioprinting for effective muscle engineering

Abstract

The debilitating effects of muscle damage, either through ischemic injury or volumetric muscle loss (VML), can have significant impacts on patients, and yet there are few effective treatments. This challenge arises when function is degraded due to significant amounts of skeletal muscle loss, beyond the regenerative ability of endogenous repair mechanisms. Currently available surgical interventions for VML are quite invasive and cannot typically restore function adequately. In response to this, many new bioengineering studies implicate 3D bioprinting as a viable option. Bioprinting for VML repair includes three distinct phases: printing and seeding, growth and maturation, and implantation and application. Although this 3D bioprinting technology has existed for several decades, the advent of more advanced and novel printing techniques has brought us closer to clinical applications. Recent studies have overcome previous limitations in diffusion distance with novel microchannel construct architectures and improved myotubule alignment with highly biomimetic nanostructures. These structures may also enhance angiogenic and nervous ingrowth post-implantation, though further research to improve these parameters has been limited. Inclusion of neural cells has also shown to improve myoblast maturation and development of neuromuscular junctions, bringing us one step closer to functional, implantable skeletal muscle constructs. Given the current state of skeletal muscle 3D bioprinting, the most pressing future avenues of research include furthering our understanding of the physical and biochemical mechanisms of myotube development and expanding our control over macroscopic and microscopic construct structures. Further to this, current investigation needs to be expanded from immunocompromised rodent and murine myoblast models to more clinically applicable human cell lines as we move closer to viable therapeutic implementation.

Simple Complexity: Incorporating Bioinspired Delivery Machinery within Self-Assembled Peptide Biogels

“…These simple, elegant, yet complex interactions also enable the microscale ordering of peptide fibrils and subsequent mechanical properties of the resultant hydrogel to be easily and effectively managed without disruption to the desirable nanofibrillar structure of the assembly [ 11 ]. This property has enabled SAP hydrogels that are mechanically weak to be combined with robust polymers to create biolinks that are stable enough to tolerate the shear profile and still enable the fine resolution of constructs for biofabrication [ 4 , 58 , 59 , 60 ].…”

“…These amino acids are chemically rich, and when incorporated into short sequences, enable intermolecular interactions such as van der Waals and electrostatic forces, hydrogen bonding and π-π stacking while avoiding the folding and intramolecular interactions present in longer polypeptides. These means the short (e.g., 1–10 residue) peptides can contribute their interactions primarily for the arrangement of molecular components into hierarchically ordered nanostructures, such as tubules, ribbons, spherical or cylindrical micelles, vesicles and hydrogels [ 3 ], all of which are promising materials for biomedical applications [ 4 ]. Importantly, the programmed and synthetically straightforward peptides enable a bottom-up strategy to create nanosized biomaterials to create functional materials for many applications, such as drug delivery and tissue engineering ( Figure 1 ) [ 5 , 6 ].…”

The Biomodified Lignin Platform: A Review

“…Using residue lignin in black ink formulations has been known since the last century, both as itself and with chemical modifications [ 250 , 251 , 252 , 253 ]. Three-dimensional printing is a state-of-the art technology that would potentially have a huge impact in the near future since it can be used for rapidly creating structures for biomedical applications, functional materials, or energy storage systems [ 254 , 255 , 256 ]. These techniques tend to use petroleum-based plastics, such as epoxy resins [ 257 ], that should be replaced by greener alternatives, such as lignin.…”

Functional biomaterials

“…Published under an exclusive license by AIP Publishing tissue engineering 18 and by Kim and Jang on recreating the 3D microenvironmental niches for modeling the diabetes mellitus. 19 Beyond macroscale and microscale manipulations of biomaterials, nanobiomaterials, as an enabling class of biomaterials, are also instrumental in healthcare applications.…”