Self-healable and dual-functional guar gum-grafted-polyacrylamidoglycolic acid-based hydrogels with nano-silver for wound dressings.

Dual-functional carbohydrate polymer-based silver nanocomposite (AgNC) hydrogels with self-healing, injectable, and bacterial inactivation properties have attracted particular attention in the wound dressing field. In this study, a rapid formation of AgNC hydrogels were prepared via in situ addition of guar gum-grafted-polyacrylamidoglycolic acid (GG-g-PAGA) polymer and silver nitrate (AgNO3) and sodium borohydride (NaBH4). The GG-g-PAGA polymer and its AgNC hydrogels were analyzed by FTIR, 1H and 13C NMR, UV-vis spectra, FE-SEM, EDX, and FE-TEM. The GG-g-PAGA@AgNC hydrogels exhibited self-healing ability, injectability, stretchability, flowability, high swelling, porosity, upright mechanical behavior, and biodegradability. Moreover, their bacterial inactivation and cytotoxicity were tested against wound pathogens and skin fibroblast cells, respectively. Therefore, incorporating GG-g-PAGA@AgNC hydrogels could be a versatile strategy to speed up wound healing processes, but a clinical trial is still required for its medical applications.

Palem RR ，Madhusudana Rao K ，Kang TJ 《-》

Novel functional antimicrobial and biocompatible arabinoxylan/guar gum hydrogel for skin wound dressing applications.

It is a challenging task to develop active biomacromolecular wound dressing materials that are biocompatible and possesses antibacterial properties against the bacterial strains that cause severe skin disease. This work is focused on the preparation of a biocompatible and degradable hydrogel for wound dressing application using arabinoxylan (ARX) and guar gum (GG) natural polymers. Fourier transform infrared spectroscopy (FT-IR) confirmed that both ARX and GG interacted well with each other, and their interactions further increased with the addition of crosslinker tetraethyl orthosilicate. Scanning electron microscope (SEM) micrographs showed uniform porous morphologies of the hydrogels. The porous morphologies and uniform interconnected pores are attributed to the increased crosslinking of the hydrogel. Elastic modulus, tensile strength, and fracture strain of the hydrogels significantly improved (from ATG-1 to ATG-4) with crosslinking. Degradability tests showed that hydrogels lost maximum weight in 7 days. All the samples showed variation in swelling with pH. Maximum swelling was observed at pH 7. The hydrogel samples showed good antibacterial activity against Pseudomonas aeruginosa (Gram-negative) and Staphylococcus aureus (Gram-positive) in PBS, good drug release profile (92% drug release), and nontoxic cellular behavior. The cells not only retained their cylindrical morphologies onto the hydrogel but were also performing their normal activities. It is, therefore, believed that as-developed hydrogel could be a potential material for wound dressing application.

Khan MUA ，Raza MA ，Razak SIA ，Abdul Kadir MR ，Haider A ，Shah SA ，Mohd Yusof AH ，Haider S ，Shakir I ，Aftab S ... -  《-》

Fabrication of multifunctional Guar gum-silver nanocomposite hydrogels for biomedical and environmental applications.

Poly(acrylamide-co-acrylamidoglycolic acid)/guar gum@ Ag-nanocomposite (AgNC@PAAG) hydrogels has been fabricated by a green protocol utilizing rhubarb stem-extract as bioreductant. The prepared nanocomposites (NCs) are formulated by varying guar gum (GG) polymer and cross-linker content, and used remarkably to study the release of an anticancer drug, 5-fluorouracil (FU). The AgNC@PAAG has demonstrated its potential in bacterial inactivation and p-nitrophenol (PNP) reduction. The AgNC@PAAG hydrogels showed extended FU release time, which was up to 23 h in pH 7.4. The higher zone of inhibition was documented for AgNC@PAAG against B. subtilis and E. coli. It was noticed that, the inhibition activity of AgNC@PAAG, was directly proportional to cross-linker content than the GG polymer. The efficiency of AgNC@PAAG as a nanocatalyst was evaluated for a model reduction reaction of p-nitrophenol (PNP) reduction by aqueous sodium borohydride (NaBH4), with an apparent rate constant of 121.8 × 10-3 min-1 at ambient temperature. The proposed nanocatalysts are reliable and recyclable, demonstrated its catalytic recycle efficacy of 85% after the third successive run. These NCs robust its biological and catalytic activity after embedding silver nanoparticles (AgNPs) by the bioreduction process; these optimized nanocatalysts can be remarkably used in biomedical healthcare sectors and industrial catalysis.

Palem RR ，Shimoga G ，Kang TJ ，Lee SH ... -  《-》

"All-in-one" self-healing and injectable cationic guar gum hydrogel dressing functionalized by bioactive complexes composed of natural small molecules.

Reducing the risk of wound infection is an urgent issue health priority. Antibacterial polysaccharide-based hydrogels have attracted great attention for infectious wounds, attributed to their safe antimicrobial performance and natural non-toxicity and biodegradability advantages. In this study, the "all-in-one" self-adaptive and injectable cationic guar gum (CG)-based polysaccharide hydrogels (FA-TOB/CG) loaded with bioactive complexes were developed for infectious wound healing. The constructed antioxidant and antibacterial ferulic acid (FA)-tobramycin (TOB) bioactive complexes (FA-TOB) were used as the cross-linking agent and introduced into the CG matrix to construct the FA-TOB/CG hydrogel with a three-dimensional porous structure. The sterilization rates of FA-TOB/CG hydrogel against S. aureus and E. coli reached 98 % and 80 % respectively. In addition, the FA-TOB/CG also exhibits enhanced antioxidant performances (DPPH: > 40 %; ABTS: > 90 %; ·OH: > 50 %). More importantly, FA-TOB/CG hydrogel also showed the ability to sustain the release of FA and TOB. These superiorities of the FA-TOB/CG hydrogel enabled it to provide a moist wound environment and promote wound healing by eliminating bacteria, modulating the local inflammatory response, and accelerating collagen deposition and vascular regeneration. Thus, this study may enlarge a new sight for developing multifunctional dressings by incorporating bioactive complexes into polysaccharide hydrogels for infected wounds.

Wang Y ，Yang M ，Yang Z ，Jiao J ，Zhao Z ，Liu Y ... -  《-》

Self-Healing Guar Gum-Based Nanocomposite Hydrogel Promotes Infected Wound Healing through Photothermal Antibacterial Therapy.

Yang W ，Zhang Q ，Zhou J ，Li L ，Li Y ，Zhu L ，Narain R ，Nan K ，Chen Y ... -  《-》