Preparation and Characterization of Nanocomposite Hydrogels Based on Self-Assembling Collagen and Cellulose Nanocrystals

Production and physico-chemical characterization of nano-sized collagen from equine tendon

In recent years, significant academic and commercial interest has focused on collagen derived from horse tendons, with potential applications across diverse sectors such as medicine, pharmaceuticals, and cosmetics. Nano collagen, with its enhanced wound penetration, improved cell contact, and heightened cellular regeneration and repair capabilities due to its high surface area, holds promise for a wide range of applications. In this study, we present a novel method for producing nano collagen from the equine tendon. Our approach is characterized by its speed, affordability, simplicity and environmentally friendly nature, with precise temperature-control to prevent collagen denaturation. We conducted a comprehensive characterization of the obtained samples, including assessments of morphology, chemical and thermal properties, particle size distribution and biocompatibility. Importantly, our results indicate improvements in thermal stability, and surface roughness of nano collagen, while preserving its molecular weight. These advancements expand the potential applications of nano collagen in various fields.

Remodeling mechanism of gel network structure of soy protein isolate amyloid fibrils mediated by cellulose nanocrystals

The differences in the gelling properties of soy protein isolate (SPI) and soy protein isolate amyloid fibrils (SAFs) as well as the role of cellulose nanocrystals (CNC) in regulating their gel behaviors were investigated in this study. The binding of CNC to β-conglycinin (7S), glycinin (11S), and SAFs was predominantly driven by non-covalent interactions. CNC addition reduced the particle size, turbidity, subunit segments, and crystallinity of SPI and SAFs, promoted the conversion of α-helix to β-sheet, improved the thermal stability, exposed more tyrosine and tryptophan residues, and enhanced the intermolecular interactions. A more regular and ordered lamellar network structure was formed in the SAFs-CNC composite gel, which could be conducive to the improvement of gel quality. This study would provide theoretical reference for the understanding of the regulatory mechanism of protein amyloid fibrils gelation as well as the high-value utilization of SAFs-CNC complex as a functional protein-based material or food ingredient in food field.

3D edible scaffolds with yeast protein: A novel alternative protein scaffold for the production of high-quality cell-cultured meat

The purpose of this study was to develop a novel edible scaffold by utilizing yeast proteins, which could partially replace collagen and produce hypoallergenic, odorless, and highly nutritious cell-cultured meat that meets the demands of a more significant number of consumers. The scaffold comprised proanthocyanidins, dialdehyde chitosan, collagen, and different proportions of yeast proteins (YP). The results indicated that the scaffold possessed excellent mechanical properties and biocompatibility, and supported cell proliferation and myogenic differentiation. Additionally, we evaluated the texture characteristics of the cultured meat models and traditional beef and discovered that the YP30 cultured meat model had similar springiness and chewiness as beef. Subsequently, further analyzed the similarity between the cultured meat models and traditional beef in appearance, taste, and nutrition. Further results illustrated that the yeast protein cultured meat model exhibited a complete model structure and comparable color and taste to beef after frying. Moreover, it was concluded that the protein content of the YP30 cultured meat model was closer to that of beef. These findings suggested that the edible scaffold using yeast proteins has enormous potential to facilitate the sustainable development of the cell-cultured meat industry.

Nanocrystalline Cellulose as a Versatile Engineering Material for Extrusion-Based Bioprinting

Naturally derived polysaccharide-based hydrogels, such as alginate, are frequently used in the design of bioinks for 3D bioprinting. Traditionally, the formulation of such bioinks requires the use of pre-reticulated materials with low viscosities, which favour cell viability but can negatively influence the resolution and shape fidelity of the printed constructs. In this work, we propose the use of cellulose nanocrystals (CNCs) as a rheological modifier to improve the printability of alginate-based bioinks whilst ensuring a high viability of encapsulated cells. Through rheological analysis, we demonstrate that the addition of CNCs (1% and 2% (w/v)) to alginate hydrogels (1% (w/v)) improves shear-thinning behaviour and mechanical stability, resulting in the high-fidelity printing of constructs with superior resolution. Importantly, LIVE/DEAD results confirm that the presence of CNCs does not seem to affect the health of immortalised chondrocytes (TC28a2) that remain viable over a period of seven days post-encapsulation. Taken together, our results indicate a favourable effect of the CNCs on the rheological and biocompatibility properties of alginate hydrogels, opening up new perspectives for the application of CNCs in the formulation of bioinks for extrusion-based bioprinting.

Cellular infiltration in an injectable sulfated cellulose nanocrystal hydrogel and efficient angiogenesis by VEGF loading

BACKGROUND

Cellular infiltration and angiogenesis into implanted biomaterial scaffolds are crucial for successful host tissue integration and tissue regeneration. Cellulose nanocrystal (CNC) is a nano-sized cellulose derivative, which can form an injectable physical gel with salts. Sulfate groups of sulfated CNC (CNC-S) can act as a binding domain to various growth factors and cytokines with a heparin-binding domain for sustained release of them. Vascular endothelial growth factor (VEGF) can promote the proliferation of endothelial cells and angiogenesis. In this study, VEGF-loaded CNC-S hydrogel was evaluated as an injectable scaffold that can induce cellular infiltration and angiogenesis.

METHODS

CNC-S was hydrolyzed to get desulfated CNC (CNC-DS), which was used as a negative control group against CNC-S. Both CNC-S and CNC-DS hydrogels were prepared and compared in terms of biocompatibility and VEGF release. The hydrogels with or without VEGF loading were subcutaneously injected into mice to evaluate the biocompatibility, cellular infiltration, and angiogenesis induction of the hydrogels.

RESULTS

Both hydrogels possessed similar stability and shear-thinning behavior to be applicable as injectable hydrogels. However, CNC-S hydrogel showed sustained release (until 8 weeks) of VEGF whereas CNC-DS showed a very fast release of VEGF with a large burst. Subcutaneously injected CNC-S hydrogel showed much enhanced cellular infiltration as well as better biocompatibility with milder foreign body response than CNC-DS hydrogel. Furthermore, VEGF-loaded CNC-S hydrogel induced significant angiogenesis inside the hydrogel whereas VEGF-loaded CNC-DS did not.

CONCLUSION

CNC-S possesses good properties as a biomaterial including injectability, biocompatibility, and allowing cellular infiltration and sustained release of growth factors. VEGF-loaded CNC-S hydrogel exhibited efficient angiogenesis inside the hydrogel. The sulfate group of CNC-S was a key for good biocompatibility and the biological activities of VEGF-loaded CNC hydrogel.