Khageswar Sahu

Bio: Khageswar Sahu is an academic researcher from Raja Ramanna Centre for Advanced Technology. The author has contributed to research in topics: Wound healing & Low level laser therapy. The author has an hindex of 11, co-authored 17 publications receiving 371 citations.

Wound healing activity of curcumin conjugated to hyaluronic acid: in vitro and in vivo evaluation

Abstract: Curcumin is a promising wound healing agent but its clinical application is limited due to hydrophobicity and lack of stability. In this article, we report the results of a study on wound healing efficacy of curcumin conjugated to hyaluronic acid (HA) which is a natural polysaccharide known to influence the healing process. Studies on proliferation, antioxidant activity and scratch wound healing carried out in human keratinocyte cells revealed that HA-conjugated curcumin treatment enhanced cell proliferation, decreased oxidative damage induced by H2O2 and also improved migration of cells in scratch wounds as compared to treatment with native curcumin. HA conjugated curcumin exhibited bactericidal activity in dark and phototoxicity when irradiated with blue light against antibiotic resistant bacteria. Furthermore, wound healing efficacy studied in diabetic mice demonstrated that topical application of the conjugate on wounds led to better healing as compared to treatment with HA-free curcumin and HA alone. These results suggest that HA conjugation is a promising formulation of curcumin for enhancing its healing efficacy.

Low-level laser therapy as an adjunct to conventional therapy in the treatment of diabetic foot ulcers

Abstract: Foot ulcers are serious complications of diabetes mellitus (DM) and are known to be resistant to conventional treatment. This study was conducted to evaluate the efficacy of low-level laser therapy (LLLT) for the treatment of diabetic foot ulcers in a tertiary care centre (Department of Surgery, Mahatma Gandhi Memorial Medical College and Maharaja Yashwantrao Hospital, A.B. Road, Indore). A total of 30 patients with type 2 DM having Meggitt-Wagner grade I foot ulcers of more than 6 weeks duration with negative culture were studied. Patients were randomized into two groups of 15 each. Patients in study group received LLLT (660 ± 20 nm, 3 J/cm2) along with conventional therapy and those in control group were treated with conventional therapy alone. The primary outcome measure was the absolute and relative wound size reduction at 2 weeks compared to the baseline parameter. Percentage ulcer area reduction was 37 ± 9% in the LLLT group and 15 ± 5.4% in the control group (p < 0.001). For ∼75% of wounds of the treatment group, wound area reduction of 30–50% was observed. In contrast, for the control group, ∼80% of wounds showed a wound area reduction of <20% on day 15. Further, the wounds with initial wound area 1000–2000 mm2 seems to have better final outcome than the groups with larger areas. The treated groups showed higher amount of granulation than the control group. The results suggest that LLLT is beneficial as an adjunct to conventional therapy in the treatment of diabetic foot ulcers.

Atomic force microscopic study on morphological alterations induced by photodynamic action of Toluidine Blue O in Staphylococcus aureus and Escherichia coli.

Abstract: Topographical alterations induced by Toluidine Blue O (TBO) mediated photodynamic treatment in Staphylococcus aureus and Escherichia coli was studied using atomic force microscopy (AFM). The AFM images showed distinct differences in the effect of photodynamic treatment on the morphology of S. aureus and E. coli. In S. aureus, photodynamic treatment with TBO resulted in light dose dependent increase in surface bleb formation suggesting breakage in the contact between the cell wall and the membrane with no significant change in the cell dimensions. Photosensitization of E. coli, resulted in surface indentations, significant reduction in the mean cell height, and flattening of bacteria as compared to the bacteria treated with the photosensitizers in the dark. These results indicate damage to the bacterial membrane and reduction of cell volume due to the loss of cytoplasmic materials. Leakage of intracellular contents measured using absorption spectrophotometry was higher and occurred faster in E. coli as compared to S. aureus and correlated with the morphological alterations. The results suggest that with AFM imaging it is possible to distinguish the membranolytic action of TBO in Gram-positive and Gram-negative bacteria.

Topical photodynamic treatment with poly- l -lysine–chlorin p6 conjugate improves wound healing by reducing hyperinflammatory response in Pseudomonas aeruginosa -infected wounds of mice

Abstract: We report the results of our investigations on the effect of antimicrobial photodynamic treatment (APDT) with poly-lysine-conjugated chlorin p6 (pl–cp6) on proinflammatory cytokine expression and wound healing in a murine excisional wound model infected with Pseudomonas aeruginosa. Treatment of infected wounds with pl–cp6 and light doses of 60 and 120 J/cm2 reduced the bacterial load by ~1.5 and 2.0 log, respectively, after 24 h. The treated wounds healed ~5 days earlier as compared to untreated control and wound closure was not dependent on light dose. Interestingly, at 96 h post-treatment, drug-treated wounds irradiated at 60 J/cm2 showed considerable reduction of proinflammatory cytokines IL-6 (approximately five times) and TNF-α (approximately four times) compared to untreated control. Further, exposure of culture supernatants to similar light dose and pl–cp6 concentration under in vitro conditions reduced the protease activity by ~50 % as compared to the untreated control, suggesting inactivation of extracellular virulent factors. Additionally, histological analysis of treated infected wounds showed complete reepithelialization, ordered collagen fibers, and considerable decrease in inflammatory cell infiltration compared to untreated wounds. These results imply that pl–cp6-mediated PDT reduces hyperinflammatory response of infected wounds, leading to acceleration of wound healing.

Effect of Helium-Neon Laser Irradiation on Hair Follicle Growth Cycle of Swiss Albino Mice

Abstract: We report the results of a study carried out to investigate the effect of helium-neon (He-Ne) laser (632.8 nm) irradiation on the hair follicle growth cycle of testosterone-treated and untreated mice.

Photoantimicrobials-are we afraid of the light?

Abstract: Although conventional antimicrobial drugs have been viewed as miraculous cure-alls for the past 80 years, increasing antimicrobial drug resistance requires a major and rapid intervention. However, the development of novel but still conventional systemic antimicrobial agents, having only a single mode or site of action, will not alleviate the situation because it is probably only a matter of time until any such agents will also become ineffective. To continue to produce new agents based on this notion is unacceptable, and there is an increasing need for alternative approaches to the problem. By contrast, light-activated molecules called photoantimicrobials act locally via the in-situ production of highly reactive oxygen species, which simultaneously attack various biomolecular sites in the pathogenic target and therefore offer both multiple and variable sites of action. This non-specificity at the target circumvents conventional mechanisms of resistance and inhibits the development of resistance to the agents themselves. Photoantimicrobial therapy is safe and easy to implement and, unlike conventional agents, the activity spectrum of photoantimicrobials covers bacteria, fungi, viruses, and protozoa. However, clinical trials of these new, truly broad-spectrum, and minimally toxic agents have been few, and the funding for research and development is almost non-existent. Photoantimicrobials constitute one of the few ways forward through the morass of drug-resistant infectious disease and should be fully explored. In this Personal View, we raise awareness of the novel photoantimicrobial technologies that offer a viable alternative to conventional drugs in many relevant application fields, and could thus slow the pace of resistance development.

Hyaluronic Acid in the Third Millennium.

Abstract: Since its first isolation in 1934, hyaluronic acid (HA) has been studied across a variety of research areas. This unbranched glycosaminoglycan consisting of repeating disaccharide units of N-acetyl-d-glucosamine and d-glucuronic acid is almost ubiquitous in humans and in other vertebrates. HA is involved in many key processes, including cell signaling, wound reparation, tissue regeneration, morphogenesis, matrix organization and pathobiology, and has unique physico-chemical properties, such as biocompatibility, biodegradability, mucoadhesivity, hygroscopicity and viscoelasticity. For these reasons, exogenous HA has been investigated as a drug delivery system and treatment in cancer, ophthalmology, arthrology, pneumology, rhinology, urology, aesthetic medicine and cosmetics. To improve and customize its properties and applications, HA can be subjected to chemical modifications: conjugation and crosslinking. The present review gives an overview regarding HA, describing its history, physico-chemical, structural and hydrodynamic properties and biology (occurrence, biosynthesis (by hyaluronan synthases), degradation (by hyaluronidases and oxidative stress), roles, mechanisms of action and receptors). Furthermore, both conventional and recently emerging methods developed for the industrial production of HA and its chemical derivatization are presented. Finally, the medical, pharmaceutical and cosmetic applications of HA and its derivatives are reviewed, reporting examples of HA-based products that currently are on the market or are undergoing further investigations.

Update on management of diabetic foot ulcers.

Abstract: Diabetic foot ulcers (DFUs) are a serious complication of diabetes that results in significant morbidity and mortality. Mortality rates associated with the development of a DFU are estimated to be 5% in the first 12 months, and 5-year morality rates have been estimated at 42%. The standard practices in DFU management include surgical debridement, dressings to facilitate a moist wound environment and exudate control, wound off-loading, vascular assessment, and infection and glycemic control. These practices are best coordinated by a multidisciplinary diabetic foot wound clinic. Even with this comprehensive approach, there is still room for improvement in DFU outcomes. Several adjuvant therapies have been studied to reduce DFU healing times and amputation rates. We reviewed the rationale and guidelines for current standard of care practices and reviewed the evidence for the efficacy of adjuvant agents. The adjuvant therapies reviewed include the following categories: nonsurgical debridement agents, dressings and topical agents, oxygen therapies, negative pressure wound therapy, acellular bioproducts, human growth factors, energy-based therapies, and systemic therapies. Many of these agents have been found to be beneficial in improving wound healing rates, although a large proportion of the data are small, randomized controlled trials with high risks of bias.

Polarized light interaction with tissues

Abstract: This tutorial-review introduces the fundamentals of polarized light interaction with biological tissues and presents some of the recent key polarization optical methods that have made possible the quantitative studies essential for biomedical diagnostics. Tissue structures and the corresponding models showing linear and circular birefringence, dichroism, and chirality are analyzed. As the basis for a quantitative description of the interaction of polarized light with tissues, the theory of polarization transfer in a random medium is used. This theory employs the modified transfer equation for Stokes parameters to predict the polarization properties of single- and multiple-scattered optical fields. The near-order of scatterers in tissues is accounted for to provide an adequate description of tissue polarization properties. Biomedical diagnostic techniques based on polarized light detection, including polarization imaging and spectroscopy, amplitude and intensity light scattering matrix measurements, and polarization-sensitive optical coherence tomography are described. Examples of biomedical applications of these techniques for early diagnostics of cataracts, detection of precancer, and prediction of skin disease are presented. The substantial reduction of light scattering multiplicity at tissue optical clearing that leads to a lesser influence of scattering on the measured intrinsic polarization properties of the tissue and allows for more precise quantification of these properties is demonstrated.