Excisional Wound Healing Model Research Articles

Experimental study of Pruthvisara taila in excised wound model in Wistar albino rats

Pruthvisara taila is a formulation indicated in the chikitsa of vrana as topical medicine in classical text Chakradatta. It contains Shuddha chitrakamoola, Shuddha vatsanabha, Shuddha karaveera, Nirgundi moola, Nadibeeja, Kanji and Karanja taila as the base. Aims and Objectives: Evaluation of wound healing property of Pruthvisara taila through experimental study. Methodology: Wound healing property in albino rats by excision wound healing model and its histopathology study. Results: Results of the study on the parameters assessed like percentage of wound contraction and histopathology study; percentage of wound closure was observed in Control group was 94.92%, in standard it was 93.73% and in test drug the percentage of wound contraction was 95.73%.The test drug, Pruthvisara taila showed more angiogenesis and formation of new blood vessels than standard group and in control group there was absence of formation of new blood vessels and proliferation of fibroblast cells. The control group did not show any collagen formation and scab formation the test drug Pruthvisara taila showed moderate formation and deposition compared to standard drug. Compared to control and standard group, the test drug, Pruthvisara taila selected in this study showed remarkable wound healing property in excised wound.

Wound Healing Effect of Lippia sidoides and Myracrodruon urundeuva Nanogel.

Wound healing is a natural regenerative response to tissue injury and the conventional treatments consists of the use wound dressings with local administration of medicines, but, in some cases, are only partially effective and limited by toxicity or ineffective anti-microbial protection. Medicinal plants such as Lippia sidoides and Myracrodruon urundeuva have shown interesting pharmacological activities, allied to this, the association of these medicinal plants and nanotechnology, could mean an advantage in relation to classical approach. This study investigated the effect of a nanogel loaded with Lippia sidoides essential oil and Myracrodruon urundeuva extract (NAA) in an excisional wound healing model in rats. Animals were anesthetized and skin wounds were made using a metal punch. The groups were treated with vehicle, NAA or collagenase gel, for 7, 14 or 21 days and then sacrificed for tissue analysis. NAA did not show acute dermal irritation, further significantly reduced (p<0.05) the final wound area, accelerated the wound contraction and organization of collagen in the group treated for 14 days. The data presented here demonstrate the therapeutic potential for the use of nanotechnology associated with medicinal plants and provides evidence that corroborate with the use of L. sidoides and M. urundeuva as healing medicinal plants.

Standardized Pre-clinical Surgical Animal Model Protocol to Investigate the Cellular and Molecular Mechanisms of Ischemic Flap Healing

BackgroundSome of the most complex surgical interventions to treat trauma and cancer include the use of locoregional pedicled and free autologous tissue transfer flaps. While the techniques used for these reconstructive surgery procedures have improved over time, flap complications and even failure remain a significant clinical challenge. Animal models are useful in studying the pathophysiology of ischemic flaps, but when repeatability is a primary focus of a study, conventional in-vivo designs, where one randomized subset of animals serves as a treatment group while a second subset serves as a control, are at a disadvantage instigated by greater subject-to-subject variability. Our goal was to provide a step-by-step methodological protocol for creating an alternative standardized, more economical, and transferable pre-clinical animal research model of excisional full-thickness wound healing following a simulated autologous tissue transfer which includes the primary ischemia, reperfusion, and secondary ischemia events with the latter mimicking flap salvage procedure.ResultsUnlike in the most frequently used classical unilateral McFarlane’s caudally based dorsal random pattern skin flap model, in the herein described bilateral epigastric fasciocutaneous advancement flap (BEFAF) model, one flap heals under normal and a contralateral flap—under perturbed conditions or both flaps heal under conditions that vary by one within-subjects factor. We discuss the advantages and limitations of the proposed experimental approach and, as a part of model validation, provide the examples of its use in laboratory rat (Rattus norvegicus) axial pattern flap healing studies. ConclusionsThis technically challenging but feasible reconstructive surgery model eliminates inter-subject variability, while concomitantly minimizing the number of animals needed to achieve adequate statistical power. BEFAFs may be used to investigate the spatiotemporal cellular and molecular responses to complex tissue injury, interventions simulating clinically relevant flap complications (e.g., vascular thrombosis) as well as prophylactic, therapeutic or surgical treatment (e.g., flap delay) strategies in the presence or absence of confounding risk factors (e.g., substance abuse, irradiation, diabetes) or favorable wound-healing promoting activities (e.g., exercise). Detailed visual instructions in BEFAF protocol may serve as an aid for teaching medical or academic researchers basic vascular microsurgery techniques that focus on precision, tremor management and magnification.Graphical

Superior rat wound-healing activity of green synthesized silver nanoparticles from acetonitrile extract of Juglans regia L: Pellicle and leaves

The process of wound healing is complicated. Antimicrobial silver has been one of the substances used for wounds since ancient times. Moreover, traditional medicine has long used Juglans regia L. to promote wound healing. Since eco-friendly nanotechnology has various uses in biomedical research, the aim of this study was to assess the wound-healing capacity of bio-reduced silver nanoparticles (AgNPs). UV, DLS, TEM, and FTIR were used to characterize the prepared AgNPs. Pellicle's bioreduced AgNP (AgNP/P) has a better polydispersity index (PI) of 0.336 compared to its chemically synthesized peers, which have a PI of 0.67. Using incision and excision wound healing models, AgNPs and extracts were compared to Solcoseryl®. Skin-breaking strength, wound contraction, epithelialization time, histology, and cytokines were all assessed. Juglans regia L. pellicle extract (P) has shown significant effectiveness in both models, as well as their bio-reduced partner AgNP/P. The skin's tensile strength following AgNP/P therapy (871 g, p value < 0.05) is comparable to that after Solcoseryl® (928 g), both of which are significantly better than AgNP (592 g) in the incision wound model. Epithelialization time (16.0 and 16.5 days) did not substantially differ from Solcoseryl® (15.3 days) (P value < 0.05). There was an elevated collagen content. Low levels of IL1β (189.0 pg/g) and high levels of TNF-α (1007.1 pg/g) in the case of AgNP/P suggest various cellular kinds of maturation and various wound healing structures that are evident in histopathology investigations. The bioreduced AgNP/P could find use as a pharmaceutical agent for wound healing dressings.

Ipomoea pes-tigridis L. extract accelerates wound healing in Wistar albino rats in excision and incision models

Ethnopharmacological relevanceAn annual herb, Ipomoea pes-tigridis L. (Convolvulaceae) is widely used for its anti-inflammatory and anti-spasmodic properties in traditional medicine. As well as treating wounds, fever, skin disorders, and other ailments, it is also used for other purposes. Aim of the studyThis study investigated polyphenolic content, antioxidant activity, RP-HPLC, wound healing, and antioxidant enzyme activity. In terms of I. pes-tigridis potential for healing wounds, there is no scientific data available. Hence this study is designed to use animal models to investigate the ethnopharmacological report. Materials methodsThe crude extracts of stem and leaf were subjected to phytochemicals, TPC, TTC, TFC, and free radical scavenging assays (DPPH, ABTS, etc). Excision and incision models were used to assess wound healing using the screened extracts (IPLEA, IPLM, IPSEA, and IPSM). Various tissue parameters (hydroxyproline, hexosamine, hexuronic acid content), as well as antioxidant enzyme activity (SOD, Catalase, GPX, LPO), were also examined. ResultsThe maximum amount of polyphenolic content was found in IPLM (TPC- 118.86 ± 5.94 mg GAE/g, TTC - 75.25 ± 2.64 mg TAE/g, and TFC-25.73 ± 0.99 mg GAE/g) with significant IC50 value of 1.65 ± 0.87 μg/mL among all the extracts. Coumaric acid was reported high (92.86 mg/g) in RP-HPLC analysis of crude extract in IPLEA. The in vivo excision wound healing model revealed that 1% IPLM had better healing property with the maximum wound healing area (0.098 ± 0.03 cm) and wound concentration (95.56 ± 1.95%) was reported with the significance level of ***P < 0.001, **P < 0.01, *P < 0.05. In the incision model, IPLM represented maximum tensile strength (27500 gf). A significant functional effect of the granulation tissue parameters and enzyme antioxidants on the wound-healed area of dry tissue was also observed. Finally, the histopathological analysis showed enhanced re-epithelialization, fibroblast proliferation, and collagen synthesis in wound-treated animal tissue in both models. ConclusionAccording to the present study, antioxidant-rich I. pes-tigridis promotes healthy cell regeneration while reducing inflammation and oxidative stress for wound healing. Additionally, it also enhances circulation and promotes healing.

Chlorogenic acid loaded niosomes and proniosomes: in vitro antioxidant and antibacterial activities with efficacy in wound healing

ObjectiveTo develop and optimize niosomal and proniosomal vesicular delivery systems for a naturally occurring polyphenol chlorogenic acid (CGA), so as to improve its physicochemical properties and permeability, which may enhance its pharmacological activity. MethodsThe formulated CGA niosomes (CGANs) and CGA proniosomes (CGAPNs) were primed by thin film hydration and phase separation coacervation methods, and were characterized with different attributes including particle size, morphology, entrapment efficiency, zeta potential, deformability, in vitro diffusion, ex vivo permeability, and long-term stability. Their efficiency was further evaluated with in vitro antioxidant assay, antibacterial assays, and excision wound healing model in rats. ResultsOptimized CGANs and CGAPNs showed spherical vesicles with particle size of 490.1 ± 43.0 and 280.0 ± 22.0 nm, polydispersity index (PDI) values of 0.526 and 0.173, and stable zeta potential values of - 29.3 ± 6.4 and - 33.2 ± 6.5 mV, respectively. The CGANs and CGAPNs vesicles showed higher entrapment (98.27% ± 0.46% & 97.27% ± 0.25%) with good deformability (8.77 ± 0.22 & 6.87 ± 0.17), higher in vitro diffusion (97.96% ± 1.67% & 91.00% ± 1.32%), and permeability coefficient values (67 × 10-3 ± 1.72 & 52 × 10-3 ± 1.09) with long-term stability in comparison with plain CGA. Enhanced 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and Fe2 + chelation ability was obtained with CGAPNs > CGANs. They also demonstrated lethal bactericidal activity on different gram positive and gram negative strains with lower minimum inhibitory concentration (MIC) values (8 × and 16 × times less) as compared with plain CGA. Significant reduction (P < 0.05) in wound area with higher wound contraction percentages on day 9 was observed with CGANPs (99.56%) > CGANs (98.44%) in comparison with marketed (92.89%) and CGA (88.89%) hydrogel. ConclusionThese results show great potential of CGANs and CGAPNs for topical wound healing application. This is the first study of CGA in niosomal and proniosomal topical delivery systems.

Topical delivery of mupirocin calcium nanostructured lipid carriers using a full-thickness excision wound healing model

Treatment of contaminated wounds represents a significant challenge in healthcare and there is a need to develop approaches maximising skin retention to maintain therapeutic concentrations of anti-infectives at the wound site. The objective of the present study was to develop and evaluate mupirocin calcium nanolipid emulgels to enhance wound healing performance and patient acceptability. Nanostructured lipid carriers (NLCs) of mupirocin calcium were prepared by the phase inversion temperature method using Precirol ATO 5 (Gattefosse, India) and oleic acid as lipids and Kolliphor RH 40 (BASF, India) as surfactant and further incorporated into a gel base for topical delivery. The particle size, polydispersity index and zeta potential of mupirocin NLCs were found to be 128.8±1.25nm, 0.283±0.003 and -24.2±0.56mV, respectively. In vitro release studies from developed emulgel showed sustained drug release over 24 hours. Ex vivo drug permeation studies through excised rat abdominal skin showed better skin permeation (1712.38±15. 57μg/cm2) from developed emulgel compared to marketed ointment (827.92±21.42μg/cm2) after 8 hours, which was in agreement with in vitro antibacterial activity. Studies on Wistar rats indicated the nonirritant potential of developed emulgels. Further, mupirocin emulgels showed improved efficacy in percent wound contraction of acute contaminated open wounds in Wistar rats using a full-thickness excision wound healing model. The emulgels of mupirocin calcium NLCs appear to be effective in the treatment of contaminated wounds due to increased skin deposition and sustained release, thereby enhancing the wound healing potential of existing molecules.

Formulation Development and Evaluation of Indian Propolis Hydrogel for Wound Healing.

Flavonoids and polyphenolic compounds play a key role in wound healing cycle modulation. Propolis, a natural bee product, has been widely reported as an enriched source of polyphenols and flavonoids as important chemical constituents and for its wound healing potential. The goal of this study was to develop and characterize a propolis-based polyvinyl alcohol (PVA) hydrogel composition with wound healing potential. To understand the impacts of critical material attributes and process parameters, formulation development was carried out using a design of experiment approach. A preliminary phytochemical analysis of Indian propolis extract showed the presence of flavonoids (23.61 ± 0.0452 mg equivalent of quercetin/g) and polyphenols (34.82 ± 0.0785 mg equivalent of gallic acid/g), both of which aid in wound healing and skin tissue regeneration. The pH, viscosity, and in vitro release of the hydrogel formulation were also studied. The burn wound healing model results revealed significant (p < 0.0001) wound contraction by propolis hydrogel (93.58 + 0.15%) with rapid re-epithelialization relative to 5% w/w povidone iodine ointment USP (Cipladine®) (95.39 + 0.16%). The excision wound healing model confirms significant (p < 0.0001) wound contraction by propolis hydrogel (91.45 + 0.29%) with accelerated re-epithelialization comparable to 5% w/w povidone iodine ointment USP (Cipladine®) (94.38 + 0.21%). The developed formulation offers promise for wound healing, which may be investigated further for clinical research.

Evaluation of wound healing activity of statin impregnated collagen scaffold in Wistar albino rats

Background: Wound healing is a dynamic process that is affected by various processes. Medications involved in wound healing can interfere with clot formation, inflammation reduction, and cell proliferation. Collagen is the natural existing compound that has the ability to enhance tissue regeneration. Various drugs used for healing have cons like inhibiting DNA, RNA, or protein synthesis, resulting in decreased fibroplasias and neovascularisation of wounds. Objective: The objective of this work is the formulation of the collagen scaffold impregnated with the Atorvastain using cow urine as solvent. Methods: The methodology involves the isolation of the collagen from the bones of the animals by using acetic acid. The obtained collagen was subjected to homogenization and sonification to get a fine powder. To this solvent, Atorvastatin and glycerine were added then it was dried at 60oC for 24 hrs to get the impregnated scaffold. The formulated scaffold was evaluated for wound healing activity by using the excision wound model. Results: The result shows that the scaffolds are good in nature and meet all the standards of the standard scaffold. The wound healing activity is assessed by using the excision wound healing model in rats. The results show the significant value of 99 % wound healing activity from the statin-impregnated scaffold. The biological parameters like total collagen, hexosamine, and uronic acid were evaluated and these observations indicated higher values of 4.024 ± 0.069, 304 ± 4.11, and 75.83 ± 1.93 compared with the plain scaffold. Conclusion: The optimised formulation exhibited good mechanical strength with better wound healing activity. The percent wound healing activity and antimicrobial activity observed from the collagen scaffold was found to be more significant compared with the scaffolds not containing statins.

CD83 expressed by macrophages is an important immune checkpoint molecule for the resolution of inflammation.

Excessive macrophage (Mφ) activation results in chronic inflammatory responses or autoimmune diseases. Therefore, identification of novel immune checkpoints on Mφ, which contribute to resolution of inflammation, is crucial for the development of new therapeutic agents. Herein, we identify CD83 as a marker for IL-4 stimulated pro-resolving alternatively activated Mφ (AAM). Using a conditional KO mouse (cKO), we show that CD83 is important for the phenotype and function of pro-resolving Mφ. CD83-deletion in IL-4 stimulated Mφ results in decreased levels of inhibitory receptors, such as CD200R and MSR-1, which correlates with a reduced phagocytic capacity. In addition, CD83-deficient Mφ upon IL-4 stimulation, show an altered STAT-6 phosphorylation pattern, which is characterized by reduced pSTAT-6 levels and expression of the target gene Gata3. Concomitantly, functional studies in IL-4 stimulated CD83 KO Mφ reveal an increased production of pro-inflammatory mediators, such as TNF-α, IL-6, CXCL1 and G-CSF. Furthermore, we show that CD83-deficient Mφ have enhanced capacities to stimulate the proliferation of allo-reactive T cells, which was accompanied by reduced frequencies of Tregs. In addition, we show that CD83 expressed by Mφ is important to limit the inflammatory phase using a full-thickness excision wound healing model, since inflammatory transcripts (e.g. Cxcl1, Il6) were increased, whilst resolving transcripts (e.g. Ym1, Cd200r, Msr-1) were decreased in wounds at day 3 after wound infliction, which reflects the CD83 resolving function on Mφ also in vivo. Consequently, this enhanced inflammatory milieu led to an altered tissue reconstitution after wound infliction. Thus, our data provide evidence that CD83 acts as a gatekeeper for the phenotype and function of pro-resolving Mφ.

Enhanced In Vivo Wound Healing Efficacy of a Novel Piperine-Containing Bioactive Hydrogel in Excision Wound Rat Model

These days an extensive amount of the attention of researchers is focused towards exploring bioactive compounds of natural or herbal origin for therapeutic intervention in different ailments of significant importance. One such novel bioactive compound that has a variety of biological properties, including anti-inflammatory and antioxidant activities, is piperine. However, until today, piperine has not been explored for its potential to improve inflammation and enhance healing in acute and chronic wounds. Therefore, the present study aimed to investigate the wound healing potential of piperine hydrogel formulation after topical application. Hydrogels fit the need for a depot system at the wound bed, where they ensure a consistent supply of therapeutic agents enclosed in their cross-linked network matrices. In the present study, piperine-containing carbopol 934 hydrogels mixed with Aloe vera gels of different gel strengths were prepared and characterized for rheological behavior, spreadability, extrudability, and percent (%) content uniformity. Furthermore, the wound healing potential of the developed formulation system was explored utilizing the excision wound healing model. The results of an in vivo study and histopathological examination revealed early and intrinsic healing of wounds with the piperine-containing bioactive hydrogel system compared to the bioactive hydrogel system without piperine. Therefore, the study's findings establish that the piperine-containing bioactive hydrogel system is a promising therapeutic approach for wound healing application that should be diligently considered for clinical transferability.

Enhanced In Vivo Wound Healing Efficacy of a Novel Hydrogel Loaded with Copper (II) Schiff Base Quinoline Complex (CuSQ) Solid Lipid Nanoparticles.

Wound dressings created using nanotechnology are known as suitable substrates to speed up the healing of both acute and chronic wounds. Therapeutic substances can be delivered using these materials. In this study, a hydrogel loaded with Cu (II) Schiff base 8-hydroxy quinoline complex (CuSQ) solid lipid nanoparticles (SLN) was formulated to investigate its wound healing potential in an excision wound healing model in rats. The CuSQ SLN were spherical shaped with sizes ranging from 111 to 202 nm and a polydispersity index (PDI) ranging from 0.43 to 0.76, encapsulation efficiency (EE) % between 85 and 88, and zeta potential (ZP) of −11.8 to −40 mV. The formulated hydrogel showed good homogeneity, good stability, and a pH of 6.4 which indicates no skin irritation and had no cytotoxicity on the human skin fibroblast (HSF) cell line. In the in vivo study, animals were placed in five groups: control, standard, plain hydrogel, low dose, and high dose of CuSQ hydrogel. Both doses of CuSQ showed significantly faster healing rates compared to standard and control rats. In addition, the histopathology study showed more collagen, improved angiogenesis, and intact re-epithelization with less inflammation. A significant increase in transforming growth factor-beta1 (TGF-β1) level and increased immune expression of vascular endothelial growth factor (VEGF) by CuSQ treatment validates its role in collagen synthesis, proliferation of fibroblasts and enhancement of angiogenesis. Matrix metalloproteinase-9 (MMP-9) was found to be significantly reduced after CuSQ treatment. Immunohistochemistry of tumor necrosis factor alpha (TNF-α) revealed a marked decrease in inflammation. Thus, we concluded that CuSQ would be a beneficial drug for cutaneous wound healing since it effectively accelerated wound healing through regulation of various cytokines and growth factors.

Exploring Silk Sericin for Diabetic Wounds: An In Situ-Forming Hydrogel to Protect against Oxidative Stress and Improve Tissue Healing and Regeneration.

Chronic wounds are one of the most frequent complications that are associated with diabetes mellitus. The overproduction of reactive oxygen species (ROS) is a key factor in the delayed healing of a chronic wound. In the present work, we develop a novel in situ-forming silk sericin-based hydrogel (SSH) that is produced by a simple methodology using horseradish peroxidase (HRP) crosslinking as an advanced dressing for wound healing. The antioxidant and angiogenic effects were assessed in vitro and in vivo after in situ application using an excisional wound-healing model in a genetically-induced diabetic db/db mice and though the chick embryo choriollantoic membrane (CAM) assay, respectively. Wounds in diabetic db/db mice that were treated with SSH closed with reduced granulation tissue, decreased wound edge distance, and wound thickness, when compared to Tegaderm, a dressing that is commonly used in the clinic. The hydrogel also promoted a deposition of collagen fibers with smaller diameter which may have had a boost effect in re-epithelialization. SSH treatment slightly induced two important endogenous antioxidant defenses, superoxide dismutase and catalase. A CAM assay made it possible to observe that SSH led to an increase in the number of newly formed vessels without inducing an inflammatory reaction. The present hydrogel may result in a multi-purpose technology with angiogenic, antioxidant, and anti-inflammatory properties, while advancing efficient and organized tissue regeneration.

Evaluation of antidiabetic and wound healing properties of ethanol extract of Hedera nepalensis in alloxan-induced diabetic rats

Natural products are known to control diabetes and its associated complications. Leaves of Hedera nepalensis are used to cure diabetes in the folklore system of medicines. The present study was designed to evaluate the in vivo antidiabetic and wound healing potentials of ethanol extract of Hedera nepalensis. Ethanolic extract ( Hn.Cr ) was prepared by maceration and was chemically characterized by HPLC methods. Antioxidant and antimicrobial properties were assessed in three in vitro models. Toxicity profile of Hn.Cr was evaluated in acute toxicological studies. Alloxan-induced diabetes model was used to access the antidiabetic attributes of Hn.Cr . Excision wound healing model was used to access the wound healing potential of Hn.Cr in alloxan-induced diabetic rats. HPLC analysis of Hn.Cr revealed the presence of phenolic and flavonoids compounds. Data of in vitro antioxidant assays showed that Hn.Cr has moderate radical scavenging potential. In vitro antimicrobial testing results revealed that Hn.Cr was active against bacterial strains (Gram +ve and Gram -ve) while no activity was observed against fungal strains used in the current study. Acute toxicity study results showed that extract was safe up to the dose of 5000 mg/kg. In vivo antidiabetic study revealed that Hn.Cr significantly ( p < 0.05) reduced the blood glucose levels in a dose and time-dependent manner. Data of the excisional wound healing model indicated that Hn.Cr accelerated wound healing in diabetic rats in a time-dependent manner. The current study concludes that multicomponent Hn.Cr has antidiabetic and wound healing properties, thus, can be used as a complementary therapy to manage hyperglycemia and wounds in diabetic patients. However, furhter studies are warranted in this regard. Graphical abstarct . • Ethanolic extract of H e dera nepalensis showed moderate antioxidant effect • Ethanolic extract of H e dera nepalensis showed in vivo antidiabetic effects • Ethanolic extract of H e dera nepalensis showed in vivo wound healing attributes

Development and Characterization of Conducting-Polymer-Based Hydrogel Dressing for Wound Healing

Normal and chronic wound healing is a global challenge. Electrotherapy has emerged as a novel and efficient technique for treating such wounds in recent decades. Hydrogel applied to the wound to uniformly distribute the electric current is an important component in wound healing electrotherapy. This study reports the development and wound healing efficacy testing of vitamin D entrapped polyaniline (PANI)-chitosan composite hydrogel for electrotherapy. To determine the morphological and physicochemical properties, techniques like scanning electron microscopy (SEM); differential scanning calorimetry; X-ray diffraction; fourier-transform infrared spectroscopy were used. Moreover, pH, conductance, viscosity, and porosity were measured to optimize and characterize the vitamin D entrapped PANI-chitosan composite hydrogel. The biodegradation was studied using lysozyme, whereas the water uptake ability was studied using phosphate buffer. Ethanolic phosphate buffer was used to perform the vitamin D entrapment and release study. Cell adhesion, proliferation, and electrical stimulation experiments were conducted by seeding dental pulp stem cells (DPSC) into the scaffolds and performing (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay; SEM images were taken to corroborated the proliferation results. The wound healing efficacy of electrotherapy and the developed hydrogel were studied on excision wound healing model in rats, and the scarfree wound healing was further validated by histopathology analysis. The composition of the developed hydrogel was optimized to include 1% w/v PANI and 2% w/v of chitosan composite. This hydrogel showed 1455 μA conduction, 98.97% entrapment efficiency and 99.12% release of vitamin D in 48 hrs. The optimized hydrogel formulation showed neutral pH of 6.96 and had 2198 CP viscosity at 26°C. The hydrogel showed 652.4% swelling index and 100% degradation in 4 weeks. The in vitro cell culture studies performed on hydrogel scaffolds using DPSC and electric stimulation strongly suggested that electrical stimulation enhances the cell proliferation in a three-dimensional (3D) scaffold environment. The in vivo excision wound healing studies also supported the in vitro results suggesting that electrical stimulation of the wound in the presence of the conducting hydrogel and growth factors like vitamin D heals the wound much faster (within 12 days) compared to non-treated control wounds (requires 21 days for complete healing). The results strongly suggested that the developed PANI-chitosan composite conducting hydrogel acts effectively as an electric current carrier to distribute the current uniformly across the wound surface. It also acted as a drug delivery vehicle for delivering vitamin D to the wound. The hydrogel provided a moist environment, a 3D matrix for free migration of the cells, and antimicrobial activity due to chitosan, all of which contributed to the electrotherapy's faster wound healing mechanism, confirmed through the in vitro and in vivo experiments.

Wound Healing Activities of Hydromethanolic Crude Extract and Solvent Fractions of Bersama abyssinica Leaves in Mice.

Background Bersama abyssinica leaves are traditionally used for management of wounds in several communities of Ethiopia, despite no scientifically approved studies done on wound healing. Our study planned to work out the wound healing effects of B. abyssinica leaves extract in mice. Methods B. abyssinica leaves were extracted with 80% hydromethanol and fractioned with chloroform, hexane, and water. The acute dermal toxicity of the crude extract was evaluated in mice. The crude extract formulated at 5% and 10% w/w ointment was investigated in excision, incision, and burn wound models and solvent fractions in the excision model using simple ointment (negative control) and nitrofurazone 0.2% w/v (positive control). We evaluated histopathological analysis, wound contraction rate, complete epithelialization period, and skin durability. One-way ANOVA followed by the post hoc Tukey HSD test with IBM SPSS software version 23.0 was used for data analysis, and p < 0.05 was considered statistically significant. Results Hydromethanolic crude extract produced 5% (99.5%) and 10% (100%) wound contraction on the 16th day of the treatment and 5% (18.8) and 10% (28.2) percent reduction in the epithelization period on the excision wound healing model. Hydromethanolic crude extract produced 5% (47.5) and 10% (61.17) percent durability on the incision wound healing model. Hydromethanolic crude extract produced 5% (99.82%) and 10% (100%) wound contraction on the 20th day of treatment and 5% (13%) and 10% (21.7%) reduction in the epithelization period on the burn wound healing model. The chloroform fraction produced 5% (90.17%) and 10% (91.01%), hexane fraction produced 5% (85.81%) and 10% (86.78%), and aqueous fraction produced 5% (99.17%) and 10% (99.38%) wound contraction on the 14th day of the treatment and 5% (18.8) and 10% (28.2) percent reduction in the epithelization period on the excision wound healing model. Both hydromethanolic crude extract and solvent fractions at 5% and 10% (w/w) were significant (p < 0.001) compared with negative control. Conclusion The results of this study showed that both 5% w/w and 10% w/w of 80% hydromethanolic crude extract and solvent fractions of B. abyssinica leaves have wound healing effects.

IN VITRO AND IN VIVO ANTIFUNGAL ACTIVITY OF ALKALOID 3,5-bis(4,4’’-dimethoxy- [1,1’:2’,1’’-terphenyl]-4’-yl)-4H-pyrazole-4,4-diol FROM DERRIS INDICA (LAM) BENNETT SEEDS

Objectives: The aim of the present study is to isolate an antifungal compound from Derris indica (Lam) Bennett seed oil with various solvents and evaluation of its antifungal activity against the clinical species of Candida. &#x0D; Methods: D. indica seed hexane extract was tested against Trichophyton rubrum, Trichophyton tonsurans and Candida albicans. Hexane extract was fractioned using different solvents through column chromatography (CC). Isolated compound D1 was identified and characterized using ultraviolet, Fourier-transform infrared, 1HNMR, and mass spectroscopy. In vitro evaluation of D1 carried out against 12 Candida strains. In vivo evaluation of D1 carried out against T. rubrum, T. tonsurans, and C. albicans using an excision wound healing model on male Wistar rats.&#x0D; Results: Different concentrations of hexane extract showed antimicrobial activity against tested microorganism with varying minimum inhibitory concentration values. On fractionation with hexane-petroleum ether through CC, it yielded a crystalline fraction. Compound D1 characterized as a 3,5-bis (4,4’’-dimethoxy-[1,1’: 2’,1’’-terphenyl]-4’-yl)-4H-pyrazole-4,4-diol. A novel alkaloid compound from D. indica is a new report and proved to be inhibitory against C. albicans MTCC 3017 (14.83±0.28), MTCC 1637 (16.0±0.0), Candida glabrata MTCC 3814 (16.83±0.28) and MTCC 3014 (16.66±0.57), Candida tropicalis MTCC 230 (20.0±0.0), MTCC 1406 (12.33±0.57). C. glabrata MTCC 3981 was found to be resistant to the compound. In vivo studies showed no visual symptoms at the end of treatment indicating the therapeutic property of the compound.&#x0D; Conclusion: The D1 was found to be effective against human fungal pathogens and can be used as a base molecule in designing new antifungal drugs.

Shape memory alloy as an internal splint in a rat model of excisional wound healing

The purpose of an animal wound model is to replicate the wound healing process of humans as accurately as possible. Although rodents are attractive candidates for animal wound models, the drawback is that their major wound healing occurs by contraction, which is fundamentally different from that seen in humans, where healing is achieved mainly by re-epithelialization and granulation tissue growth. There has been an attempt to overcome such drawbacks by applying an external splint on wounded mice. This model, however, has a few problems concerning the assimilating ability of external splints with the dynamic soft tissue movements and robustness issues. The authors hereby describe a new animal wound model using an internal splint made of nitinol, one of the shape memory alloys (SMAs). SMA wire was inserted intradermally around the full-thickness excisional wound to act as the internal splint, and its ability to impede wound contraction was analyzed. In experiment 1, three different sizes of SMAs (0.18 mm, 0.24 mm, and 0.30 mm diameters of thickness) were inserted as the internal splint and their ability to impede the wound contraction was compared. The most effective size of SMA as the internal splint was selected among them. In experiment 2, contraction of the wound with the selected size of SMA inserted as the internal splint was compared with that of the unsplinted wound. SMA as an internal splint effectively impeded wound contraction without affecting the re-epithelialization rate, thereby successfully mimicking the human wound healing mechanism. In this study, the authors introduce a novel animal wound model that replicates the human wound healing mechanism. This model is robust, reliable, and easily reproducible.

Effects of chitosan-collagen dressing on wound healing in vitro and in vivo assays.

The present study was designed to fabricate a new chitosan-collagen sponge (CCS) for potential wound dressing applications. CCS was fabricated by a 3.0% chitosan mixture with a 1.0% type I collagen (7:3(w/w)) through freeze-drying. Then the dressing was prepared to evaluate its properties through a series of tests. The new-made dressing demonstrated its safety toward NIH3T3 cells. Furthermore, the CCS showed the significant surround inhibition zone than empty controls inoculated by E. coli and S. aureus. Moreover, the moisture rates of CCS were increased more rapidly than the collagen and blank sponge groups. The results revealed that the CCS had the characteristics of nontoxicity, biocompatibility, good antibacterial activity, and water retention. We used a full-thickness excisional wound healing model to evaluate the in vivo efficacy of the new dressing. The results showed remarkable healing at 14th day post-operation compared with injuries treated with collagen only as a negative control in addition to chitosan only. Our results suggest that the chitosan-collagen wound dressing were identified as a new promising candidate for further wound application.

Knockout of sodium channel Nax delays re-epithelializathion of splinted murine excisional wounds.

Mammalian wound healing is a carefully orchestrated process in which many cellular and molecular effectors respond in concert to perturbed tissue homeostasis in order to close the wound and re-establish the skin barrier. The roles of many of these molecular effectors, however, are not entirely understood. Our lab previously demonstrated that the atypical sodium channel Nax (encoded by Scn7a) responds to wound-induced epidermal dehydration, resulting in molecular cascades that drive pro-inflammatory signaling. Acute inhibition of Nax was sufficient to attenuate dermatopathological symptoms in models of hypertrophic scar and dermatitis. To date, however, the role of Nax in excisional wound healing has not been demonstrated. Here we report development of a knockout mouse that lacks expression of functional Nax , and we demonstrate that lack of functional Nax results in deficient wound healing in a murine splinted excisional wound healing model. This deficiency in wound healing was reflected in impaired re-epithelialization and decreased keratinocyte proliferation, a finding which was further supported by decreased proliferation upon Nax knockdown in HaCaT cells in vitro. Defective wound healing was observed alongside increased expression of inflammatory genes in the wound epidermis of Nax -/- mice, suggesting that mice lacking functional Nax retain the ability to undergo skin inflammation. Our observations here motivate further investigation into the roles of Nax in wound healing and other skin processes.