Vignesh Muthuvijayan

Bio: Vignesh Muthuvijayan is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Materials science & Self-healing hydrogels. The author has an hindex of 14, co-authored 38 publications receiving 543 citations. Previous affiliations of Vignesh Muthuvijayan include University of Maryland, Baltimore County & Indian Institutes of Technology.

Development of reduced graphene oxide (rGO)-isabgol nanocomposite dressings for enhanced vascularization and accelerated wound healing in normal and diabetic rats.

Abstract: Treatment of chronic non-healing wounds in diabetes is still a major clinical challenge. Here, we have developed reduced graphene oxide (rGO) loaded isabgol nanocomposite scaffolds (Isab + rGO) to treat normal and diabetic wounds. rGO was synthesized by rapid reduction of graphene oxide (GO) under focused solar radiation. Then, rGO was uniformly dispersed into isabgol solution to prepare Isab + rGO nanocomposite scaffolds. These scaffolds were characterized using various physiochemical techniques. Isab + rGO nanocomposite scaffolds showed suitable cell viability, proliferation, and attachment. In vivo experiments were performed using Wistar rats to study the wound healing efficacy of these scaffolds in normal and diabetic rats. Results revealed that rGO stimulated collagen synthesis, collagen crosslinking, wound contraction, and reduced the wound re-epithelialization time significantly compared to control. Histology and immunohistochemistry analyses showed that Isab + rGO scaffold treatment enhanced angiogenesis, collagen synthesis, and deposition in treated wounds. Isab + rGO scaffold treatment also played a major role in shortening the inflammation phase and recruiting macrophages to enhance the early phase of wound healing. Overall, this investigation showed that Isab + rGO scaffold dressing could significantly accelerate the healing of normal and diabetic wounds.

Accelerated Healing of Diabetic Wounds Treated with L-Glutamic acid Loaded Hydrogels Through Enhanced Collagen Deposition and Angiogenesis: An In Vivo Study.

Abstract: We have developed L-glutamic acid (LG) loaded chitosan (CS) hydrogels to treat diabetic wounds. Although literature reports wound healing effects of poly(glutamic acid)-based materials, there are no studies on the potential of L-glutamic acid in treating diabetic wounds. As LG is a direct precursor for proline synthesis, which is crucial for collagen synthesis, we have prepared CS + LG hydrogels to accelerate diabetic wound healing. Physiochemical properties of the CS + LG hydrogels showed good swelling, thermal stability, smooth surface morphology, and controlled biodegradation. The addition of LG to CS hydrogels did not alter their biocompatibility significantly. CS + LG hydrogel treatment showed rapid wound contraction compared to control and chitosan hydrogel. Period of epithelialization is significantly reduced in CS + LG hydrogel treated wounds (16 days) compared to CS hydrogel (20 days), and control (26 days). Collagen synthesis and crosslinking are also significantly improved in CS + LG hydrogel treated diabetic rats. Histopathology and immunohistochemistry results revealed that the CS + LG hydrogel dressing accelerated vascularization and macrophage recruitment to enhance diabetic wound healing. These results demonstrate that incorporation of LG can improve collagen deposition, and vascularization, and aid in faster tissue regeneration. Therefore, CS + LG hydrogels could be an effective wound dressing used to treat diabetic wounds.

Reduced graphene oxide-loaded nanocomposite scaffolds for enhancing angiogenesis in tissue engineering applications

Abstract: Tissue engineering combines cells, scaffolds and signalling molecules to synthesize tissues in vitro. However, the lack of a functioning vascular network severely limits the effective size of a tissue-engineered construct. In this work, we have assessed the potential of reduced graphene oxide (rGO), a non-protein pro-angiogenic moiety, for enhancing angiogenesis in tissue engineering applications. Polyvinyl alcohol/carboxymethyl cellulose (PVA/CMC) scaffolds loaded with different concentrations of rGO nanoparticles were synthesized via lyophilization. Characterization of these scaffolds showed that the rGO-loaded scaffolds retained the thermal and physical properties (swelling, porosity and in vitro biodegradation) of pure PVA/CMC scaffolds. In vitro cytotoxicity studies, using three different cell lines, confirmed that the scaffolds are biocompatible. The scaffolds containing 0.005 and 0.0075% rGO enhanced the proliferation of endothelial cells (EA.hy926) in vitro. In vivo studies using the chick chorioallantoic membrane model showed that the presence of rGO in the PVA/CMC scaffolds significantly enhanced angiogenesis and arteriogenesis.

Morin incorporated polysaccharide─protein (psyllium─keratin) hydrogel scaffolds accelerate diabetic wound healing in Wistar rats

Abstract: Chronic wounds cost several billion dollars of public healthcare spending annually and continue to be a persistent threat globally. Several treatment methods have been explored, and all of them involve covering up the wound with therapeutic dressings that reduce inflammation and accelerate the healing process. In this present study, morin (MOR) was loaded onto hydrogel scaffolds prepared from psyllium seed husk polysaccharide (PSH), and human hair keratins (KER) crosslinked with sodium trimetaphosphate. ATR-FTIR confirmed the presence of the constituent chemical ingredients. SEM images of the scaffold surface reveal a highly porous architecture, with about 80% porosity measured by liquid displacement measurement, irrespective of the morin concentration. Swelling assays carried out on the scaffolds portray an ability to absorb up to seven times their dry weight of fluids. This makes them attractive for guiding moist wound healing on medium exuding wounds. An Alamar blue assay of NIH/3T3 fibroblast cells shows that cell viability decreases in the first 24 h but recovers to 85% in comparison to a control after 48 h. SEM images of fibroblast cells grown on the scaffolds confirm cellular attachment. An in vivo diabetic wound healing study showed that PSH + KER + MOR scaffold treatment significantly reduced the re-epithelialization time (p < 0.01) and enhanced the rate of wound contraction (p < 0.001), by accelerating collagen synthesis in diabetic rats compared to controls.

Functional Graphene Nanomaterials Based Architectures: Biointeractions, Fabrications, and Emerging Biological Applications

Abstract: Functional graphene nanomaterials (FGNs) are fast emerging materials with extremely unique physical and chemical properties and physiological ability to interfere and/or interact with bioorganisms; as a result, FGNs present manifold possibilities for diverse biological applications. Beyond their use in drug/gene delivery, phototherapy, and bioimaging, recent studies have revealed that FGNs can significantly promote interfacial biointeractions, in particular, with proteins, mammalian cells/stem cells, and microbials. FGNs can adsorb and concentrate nutrition factors including proteins from physiological media. This accelerates the formation of extracellular matrix, which eventually promotes cell colonization by providing a more beneficial microenvironment for cell adhesion and growth. Furthermore, FGNs can also interact with cocultured cells by physical or chemical stimulation, which significantly mediate their cellular signaling and biological performance. In this review, we elucidate FGNs–bioorganism int...

Advances and Impact of Antioxidant Hydrogel in Chronic Wound Healing.

Abstract: The accelerating and thorough treatment of chronic wounds still represents a major unmet medical need owing to the complex symptoms resulting from metabolic disorder of the wound microenvironment. Although numerous strategies and bioactive hydrogels are developed, an effective and widely used method of chronic wound treatment remains a bottleneck. With the aim to accelerate chronic wound healing, many hydrogel dressings with antioxidant functions have emerged and are proven to accelerate wound healing, especially for chronic wound repair. The new strategy in chronic wound treatment brought by antioxidant hydrogels is of great significance to human health. Here, the application of antioxidant hydrogels in the repair of chronic wounds is discussed systematically, aiming to provide an important theoretical reference for the further breakthrough of chronic wound healing.

Biomedical applications of biodegradable polymers

Abstract: Utilization of polymers as biomaterials has greatly impacted the advancement of modern medicine. Specifically, polymeric biomaterials that are biodegradable provide the significant advantage of being able to be broken down and removed after they have served their function. Applications are wide ranging with degradable polymers being used clinically as surgical sutures and implants. To fit functional demand, materials with desired physical, chemical, biological, biomechanical, and degradation properties must be selected. Fortunately, a wide range of natural and synthetic degradable polymers has been investigated for biomedical applications with novel materials constantly being developed to meet new challenges. This review summarizes the most recent advances in the field over the past 4 years, specifically highlighting new and interesting discoveries in tissue engineering and drug delivery applications.