Accelerated wound closure: Systematic evaluation of cellulose acetate effects on biologically active molecules release from amniotic fluid stem cells

Synthesis, Properties, Applications, and Future Prospective of Cellulose Nanocrystals

The exploration of nanocellulose has been aided by rapid nanotechnology and material science breakthroughs, resulting in their emergence as desired biomaterials. Nanocellulose has been thoroughly studied in various disciplines, including renewable energy, electronics, environment, food production, biomedicine, healthcare, and so on. Cellulose nanocrystal (CNC) is a part of the organic crystallization of macromolecular compounds found in bacteria's capsular polysaccharides and plant fibers. Owing to numerous reactive chemical groups on its surface, physical adsorption, surface grating, and chemical vapor deposition can all be used to increase its performance, which is the key reason for its wide range of applications. Cellulose nanocrystals (CNCs) have much potential as suitable matrices and advanced materials, and they have been utilized so far, both in terms of modifying and inventing uses for them. This work reviews CNC's synthesis, properties and various industrial applications. This review has also discussed the widespread applications of CNC as sensor, acoustic insulator, and fire retardant material.

Collagen/Nigella sativa/chitosan inscribed electrospun hybrid bio-nanocomposites for skin tissue engineering

The sophisticated new tissue regeneration focused on nanocomposite with different morphologies achieved through advanced manufacturing technology with the inclusion of bio-inscribed materials has piqued the research community's interest. This research aims at developing hybrid bio-nanocomposites with collagen (Col), Nigella sativa (Ns) oil and chitosan (Cs) by a bi-layered green electrospinning on polyvinyl chloride (PVA) layer in a different ratio for tissue regeneration. Fiber morphologies through scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), moisture management, tensile test, antibacterial activity, cell cytotoxicity and wound healing through rabbit model of the fabricated hybrid bio-nanocomposites were investigated. It is worth noting that water-soluble Col (above 60% solution) does not form Taylor cones during electrospinning because unable to overcome the surface tension of the solution (viscosity) to form fibers. The results show that water soluble Col (50% solution) to Cs (25% solution) and Ns (25% solution) has good fiber formation with mean diameter 384 ± 27 nm and degree of porosity is 79%. The fast-absorbing and slow-drying hybrid bio-nanocomposites maintain a moist environment for wounds and allowing gaseous exchange for cell migration and proliferation by the synergistic effects of bio-polymers. All of the biopolymers in bio-nanocomposite improve the H-bonds, which accounts for enough tensile strength to withstand cell pulling force. The antibacterial ZOI concentrations against S. aureus and E. coli were 10 and 8 mm, respectively, which appeared to be sufficient to inhibit bacterial action with 100% cell viability (cytotoxicity). The synergistic effects of Ns and Cs improve tissue regeneration, while native Col improves antibacterial activity, and the rabbit model achieves approximately 84% wound closure in only 10 days, which is 1.5 times faster than the control model. So, the fabricated hybrid bio-composites may be useful for skin tissue engineering.

The Bumpy Road to Stem Cell Therapies: Rational Design of Surface Topographies to Dictate Stem Cell Mechanotransduction and Fate

Cells sense and respond to a variety of physical cues from their surrounding microenvironment, and these are interpreted through mechanotransductive processes to inform their behavior. These mechanisms have particular relevance to stem cells, where control of stem cell proliferation, potency, and differentiation is key to their successful application in regenerative medicine. It is increasingly recognized that surface micro- and nanotopographies influence stem cell behavior and may represent a powerful tool with which to direct the morphology and fate of stem cells. Current progress toward this goal has been driven by combined advances in fabrication technologies and cell biology. Here, the capacity to generate precisely defined micro- and nanoscale topographies has facilitated the studies that provide knowledge of the mechanotransducive processes that govern the cellular response as well as knowledge of the specific features that can drive cells toward a defined differentiation outcome. However, the path forward is not fully defined, and the "bumpy road" that lays ahead must be crossed before the full potential of these approaches can be fully exploited. This review focuses on the challenges and opportunities in applying micro- and nanotopographies to dictate stem cell fate for regenerative medicine. Here, key techniques used to produce topographic features are reviewed, such as photolithography, block copolymer lithography, electron beam lithography, nanoimprint lithography, soft lithography, scanning probe lithography, colloidal lithography, electrospinning, and surface roughening, alongside their advantages and disadvantages. The biological impacts of surface topographies are then discussed, including the current understanding of the mechanotransductive mechanisms by which these cues are interpreted by the cells, as well as the specific effects of surface topographies on cell differentiation and fate. Finally, considerations in translating these technologies and their future prospects are evaluated.