The rotation of mouse myoblast nuclei is dependent on substrate elasticity

Nano-/micro-scaled hydroxyapatite ceramic construction and the regulation of immune-associated osteogenic differentiation

Hydroxyapatite (HA) bioceramic is a promising substitute for bone defects, and the surface properties are major factors that influence bioactivity and osteoinductivity. In this study, two kinds of HA bioceramics with nanoscale (n-HA) and microscale (m-HA) surface topography were designed to mimic the natural bone, thus enhancing the stimulation of osteogenic differentiation and revealing the potential mechanism. Compared to m-HA, n-HA owned a larger surface roughness, a stronger wettability, and reduced hardness and indentation modulus. Based on these properties, n-HA could maintain the conformation of vitronectin better than m-HA, which may contribute to higher cellular activities and a stronger promotion of osteogenic differentiation of mesenchymal stem cells (MSCs). Further RNA sequencing analysis compared the molecular expression between n-HA and m-HA. Six hundred twenty-seven differentially expressed genes were identified in MSCs, and 17 upregulated genes and 610 downregulated genes were included when n-HA compared to m-HA. The GO cluster analysis and enriched Kyoto encyclopedia of genes and genome signaling pathways revealed a close correlation with the immune process in both upregulated (chemokine signaling pathway and cytokine-cytokine receptor interaction) and downregulated pathways (osteoclasts differentiation). It suggested that the nanoscale surface topography of HA enhanced the osteoinductivity of MSCs and could not be separated from its regulation of immune function and the retention of adsorbed protein conformation.

Homemade bread: Repurposing an ancient technology for in vitro tissue engineering

Numerous biomaterial scaffolds have been developed which provide architectures to support the proliferation of mammalian cells. Scaffolds derived from plant components have been utilized in several tissue engineering applications, including the production of cultured meats. Bread crumb is a common ingredient employed as a texturizer and filler in existing manufacturing processes for the production of animal meat products. Though an unconventional choice as a scaffolding material, we developed a yeast-free "soda bread" with controllable porosity and mechanical properties which is stable over several weeks in culture with fibroblasts, myoblasts and pre-osteoblasts. All cells were able to proliferate throughout the three-dimensional scaffolds, depositing extra-cellular matrix while exhibiting low stress and high viability. Importantly, myoblasts were also able to differentiate into myotubes, a key step required for the culture of skeletal muscle tissue. The results suggest opportunities for the dual-use possibility of utilizing existing texturizer and filler components in future lab grown meat products, however this will of course require further validation. Regardless, the bread-derived scaffolds presented here are simply produced, inherently edible and support muscle tissue engineering, qualities which highlight their utility in the production of future meat products.

Cellulose Biomaterials for Tissue Engineering

In this review, we highlight the importance of nanostructure of cellulose-based biomaterials to allow cellular adhesion, the contribution of nanostructure to macroscale mechanical properties, and several key applications of these materials for fundamental scientific research and biomedical engineering. Different features on the nanoscale can have macroscale impacts on tissue function. Cellulose is a diverse material with tunable properties and is a promising platform for biomaterial development and tissue engineering. Cellulose-based biomaterials offer some important advantages over conventional synthetic materials. Here we provide an up-to-date summary of the status of the field of cellulose-based biomaterials in the context of bottom-up approaches for tissue engineering. We anticipate that cellulose-based material research will continue to expand because of the diversity and versatility of biochemical and biophysical characteristics highlighted in this review.

Freeform Perfusable Microfluidics Embedded in Hydrogel Matrices

We report a modification of the freeform reversible embedding of suspended hydrogels (FRESH) 3D printing method for the fabrication of freeform perfusable microfluidics inside a hydrogel matrix. Xanthan gum is deposited into a CaCl₂ infused gelatine slurry to form filaments, which are consequently rinsed to produce hollow channels. This provides a simple method for rapid prototyping of microfluidic devices based on biopolymers and potentially a new approach to the construction of vascular grafts for tissue engineering.