Leaf on a Film: Mesoporous Silica-Based Epoxy Composites with Superhydrophobic Biomimetic Surface Structure as Anti-Corrosion and Anti-Biofilm Coatings.

In this study, a series of amine-modified mesoporous silica (AMS)-based epoxy composites with superhydrophobic biomimetic structure surface of Xanthosoma sagittifolium leaves (XSLs) were prepared and applied as anti-corrosion and anti-biofilm coatings. Initially, the AMS was synthesized by the base-catalyzed sol-gel reaction of tetraethoxysilane (TEOS) and triethoxysilane (APTES) through a non-surfactant templating route. Subsequently, a series of AMS-based epoxy composites were prepared by performing the ring-opening polymerization of DGEBA with T-403 in the presence of AMS spheres, followed by characterization through FTIR, TEM, and CA. Furthermore, a nano-casting technique with polydimethylsiloxane (PDMS) as the soft template was utilized to transfer the surface pattern of natural XSLs to AMS-based epoxy composites, leading to the formation of AMS-based epoxy composites with biomimetic structure. From a hydrophilic CA of 69°, the surface of non-biomimetic epoxy significantly increased to 152° upon introducing XSL surface structure to the AMS-based epoxy composites. Based on the standard electrochemical anti-corrosion and anti-biofilm measurements, the superhydrophobic BEAMS3 composite was found to exhibit a remarkable anti-corrosion efficiency of ~99% and antimicrobial efficacy of 82% as compared to that of hydrophilic epoxy coatings.

Healing Wounds Efficiently with Biomimetic Soft Matter: Injectable Self-Healing Neutral Glycol Chitosan/Dibenzaldehyde-Terminated Poly(ethylene glycol) Hydrogel with Inherent Antibacterial Properties.

The high prevalence of acquiring skin wounds, along with the emergence of antibiotic-resistant strains that lead to infections, impose a threat to the physical, mental, and socioeconomic health of society. Among the wide array of wound dressings developed, hydrogels are regarded as a biomimetic soft matter of choice owing to their ability to provide a moist environment ideal for healing. Herein, neutral glycol chitosan (GC) was cross-linked via imine bonds with varying concentrations of dibenzaldehyde-terminated polyethylene glycol (DP) to give glycol chitosan/dibenzaldehyde-terminated polyethylene glycol hydrogels (GC/DP). These dynamic Schiff base linkages (absorption peak at 1638 cm-1) within the hydrogel structure endowed their ability to recover from damage as characterized by high-low strain exposure in continuous step strain rheology. Along with their good injectability and biodegradability, the hydrogels exhibited remarkable inhibition against E. coli, P. aeruginosa, and S. aureus. GC/DP hydrogels demonstrated high LC50 values in vivo using zebrafish embryos as a model system due to their relative biocompatibility and a remarkable 93.4 ± 0.88% wound contraction at 30-dpw against 49.1 ± 3.40% of the control. To the best of our knowledge, this is the first study that developed injectable glycol chitosan/dibenzaldehyde-terminated polyethylene glycol self-healing hydrogels for application in wound healing with intrinsic bacteriostatic properties against the three bacteria.

Innovation inspired by nature: Biocompatible self-healing injectable hydrogels based on modified-ß-chitin for wound healing.

Remarkable properties of hydrogels are compromised by failure to recover from damage, bringing their intended functions to an end. To address this, hydrogels can be functionalized with self-healing property to enable them to restore themselves after damage, thus, extending their lifetime. Herein, hydrogels were prepared by cross-linking acrylamide-modified ß-chitin (Am-ß-Chn) with alginate dialdehyde (ADA) to form Schiff base, showing IR characteristic peak at 1650 cm-1, attributed to the stretching vibration of CN. The dynamic Schiff base and H-bond rendered the double crosslinked hydrogels self-healing as demonstrated by continuous step strain rheology. Characterization of the hydrogels revealed excellent biocompatibility, biodegradability, injectability and self-healing properties. Furthermore, the wound healing property of the hydrogels was investigated in vivo using zebrafish as a model system. Indirect application of Am-ß-Chn/ADA hydrogel remarkably led to ~87% wound healing as compared to control which gave ~50%, suggesting that hydrogels are effective in accelerating wound healing. However, a clear understanding of the exact mechanism of its wound healing property remains to be investigated. To the best of our knowledge, this is the first innovation of developing novel double crosslinked Am-ß-Chn/ADA hydrogels with both self-healing and accelerated wound healing properties, directly from marine-food wastes.

Marine waste to a functional biomaterial: Green facile synthesis of modified-ß-chitin from Uroteuthis duvauceli pens (gladius).

Chitin is the second most abundant biomass on earth but exploited the least. In this study, wastes from Uroteuthis duvauceli was utilized to extract 38.79 ±â€¯1.38% dry weight of ß-chitin using a new combination of decolorization, demineralization, and deproteinization processes. ß-chitin was then derivatized with acrylamide in an efficient and green aqueous 8 wt% NaOH/4 wt% urea solvent via one-pot etherification. The success of carbamoylethyl ether of chitin and carboxyethyl chitin synthesis was confirmed by FTIR, 1H NMR, 13C NMR, XRD, SEM, TGA, and DSC. The synthesized acrylamide-modified ß-chitin derivatives were shown to exhibit water solubility and lower decomposition temperatures, which are primarily due to the disruption of the crystalline structure of ß-chitin upon its dissolution and modification. In this era of climate change, this desirable strategy of harnessing ß-chitin from wastes and converting it to value-added products is highly sought to mitigate the continuing ecological and economical imbalance brought about by marine-food wastes. To the best of our knowledge, this novel contribution is the first to report biorefinery of squid pens from this particular species and functionalizing it with acrylamide in a facile manner, thus, offering greater potential for future development to biocompatible chitin-based biomaterials intended for industrial, pharmaceutical and biomedical applications.