Direct and Indirect Cationization of Cellulose Nanocrystals: Structure-Properties Relationship and Virus Capture Activity

Functionalized cellulose nanocrystals reinforced PLA-gelatin electrospun fibers for potential antibacterial wound dressing and coating applications

This study addresses the critical need for effective antibacterial materials by exploring the innovative integration of dimethyloctadecyl [3-(trimethoxysilyl)propyl] ammonium chloride (DTSACl) onto cellulose nanocrystal (CNC), followed by its incorporation into polylactic acid and gelatin matrices to engineer antibacterial nanofiber mats. The modification of CNC with DTSACl (QACNC) was studied and confirmed by FT-IR, 13C NMR, and XRD analysis. Furthermore, the impact of such addition on the morphology, mechanical, hydrophobic properties, and antibacterial efficacy of the resultant QACNC nanofibers were thoroughly investigated. It was found that the QACNC inhibited the growth of Staphylococcus aureus by 99 % but had no effect on Pseudomonas aeruginosa at 125 μg/mL concentration. Various concentrations of QACNC were blended into the as-spun PLA/Gel solutions before spinning or coated onto spun PLA/Gel nanofiber mats. There was a minor antibacterial effect observed with PLA/Gel mats blended with up to 3 wt% QCNC, while the average inhibition for PLA/Gel/QACNC 5 wt% was 68.3 % ± 36.5 %. By increasing the amount of QACNC blended into the polymer matrix, the human dermal fibroblast (HDF) cell viability decreased, indicating that optimizing QACNC concentrations is crucial for maintaining cell viability while ensuring effective antibacterial performance. Given the enhanced antibacterial properties, the fabricated textiles hold significant potential for applications in medical textiles and wound dressings.

Surface modification of cellulose nanocrystals for biomedical and personal hygiene applications

The increasing demand for sustainable and effective materials in biomedical and personal hygiene applications has driven the exploration of cellulose nanocrystals (CNCs) derived from biomass. These nanomaterials are highly valued for their exceptional mechanical properties, biocompatibility, and renewable nature. Researchers are exploring CNCs for advancing medical and hygiene products, but surface modification is often needed to maximize their benefits. Techniques such as chemical functionalization, physical coating, and hybridization can significantly enhance CNCs dispersibility, stability, and interaction with biological systems. This versatility makes CNCs suitable for a variety of applications, including drug delivery systems, wound dressings, and personal hygiene products. Despite their advantages, maintaining the inherent properties of CNCs while integrating new functionalities through modification poses a challenge. Understanding the impact of various modification techniques on CNC performance is crucial for optimizing their effectiveness. This review aimed to consolidate current knowledge on the surface modification of biomass-derived CNCs, offering insights into different methods and their implications for biomedical and personal hygiene applications. By highlighting advancements, challenges, and prospects, it served as a crucial resource for advancing the development and application of CNCs in these critical fields.

Modulation of the Chirality and Dynamics of Self-Assembled Nanocellulose-Chiral C-Dot Film for Chiral Sensing Applications

The detection and sensing of chirality using chiral biomaterials are growing areas of research in advanced bioelectronics. As a result, chiral-controlled biomaterials are crucial for advancing current technologies in chiral sensing applications within biosystems. A chiral carbon dot (C-dot) modulated self-assembled emissive cellulose nanocrystal (CNC) film is developed where the chirality of the CNC film can be tempered between left-handed and right-handed chirality after being doped with chiral L/D-C-dots in CNCs (C-dot-CNC film), transferring the chirality from C-dots to CNCs. The interaction between C-dots, CNCs, and carrier dynamics is investigated using a variety of steady-state and time-resolved PL spectroscopy techniques. The chiral C-dot enhanced the protonic conductivity across the CNC via the formation of hydrogen bonds with its surface functional groups and water molecules. Further, the chiral CNC-C-dots photoelectrodes demonstrate an excellent ability to distinguish between left-handed and right-handed small molecules. These findings on the underlying mechanism of spin selectivity between chiral CNC-C-dot and chiral ligand hold promise for the development of efficient chiral-sensing electronic devices.

Innovations in hydrogel-based manufacturing: A comprehensive review of direct ink writing technique for biomedical applications

Direct ink writing (DIW) stands as a pioneering additive manufacturing technique that holds transformative potential in the field of hydrogel fabrication. This innovative approach allows for the precise deposition of hydrogel inks layer by layer, creating complex three-dimensional structures with tailored shapes, sizes, and functionalities. By harnessing the versatility of hydrogels, DIW opens up possibilities for applications spanning from tissue engineering to soft robotics and wearable devices. This comprehensive review investigates DIW as applied to hydrogels and its multifaceted applications. The paper introduces a diverse range of printing techniques while providing a thorough exploration of DIW for hydrogel-based printing. The investigation aims to explain the progress made, challenges faced, and potential trajectories that lie ahead for DIW in hydrogel-based manufacturing. The fundamental principles underlying DIW are carefully examined, specifically focusing on rheological attributes and printing parameters, prompting a comprehensive survey of the wide variety of hydrogel materials. These encompass both natural and synthetic variations, all of which can be effectively harnessed for this purpose. Furthermore, the review explores the latest applications of DIW for hydrogels in biomedical areas, with a primary focus on tissue engineering, wound dressing, and drug delivery systems. The document not only consolidates the existing state of DIW within the context of hydrogel-based manufacturing but also charts potential avenues for further research and innovative breakthroughs.

Quaternized Chitosan Derivatives as Viable Antiviral Agents: Structure-Activity Correlations and Mechanisms of Action

Cationic polysaccharides have demonstrated significant antimicrobial properties and have great potential in medical applications, where the antiviral activity is of great interest. As of today, alcohols and oxidizing agents are commonly used as antiviral disinfectants. However, these compounds are not environmentally safe, have short activity periods, and may cause health issues. Therefore, this study aimed to develop metal-free and environmentally friendly quaternary chitosans (QCs) with excellent long-lasting virucidal activity. To evaluate this, both single and double QCs were obtained using AETMAC ([2-(acryloyloxy)ethyl]-trimethylammonium chloride) and GTMAC (glycidyl trimethylammonium chloride) quaternary precursors. Further, this study investigated the influence of the quaternary functional group, charge density, and molecular weight (M_w) on the antiviral properties of QCs. It is proposed that the higher charge density, along with the length of alkyl linkers, and hydrophobic interactions affected the antiviral activity of QCs. The findings demonstrated that heterogeneously functionalized chitosan exhibited excellent antiviral activity against both the enveloped virus φ6 and the nonenveloped viruses φX174 and MS2. These quaternized chitosan derivatives have promising potential as viable antiviral agents, as hand/surface sanitizers, or in other biomedical applications.