Rat Wound Model Research Articles

Rough Carbon-Iron Oxide Nanohybrids for Near-Infrared-II Light-Responsive Synergistic Antibacterial Therapy.

Infections caused by multidrug resistant bacteria are still a serious threat to human health. It is of great significance to explore effective alternative antibacterial strategies. Herein, carbon-iron oxide nanohybrids with rough surfaces (RCF) are developed for NIR-II light-responsive synergistic antibacterial therapy. RCF with excellent photothermal property and peroxidase-like activity could realize synergistic photothermal therapy (PTT)/chemodynamic therapy (CDT) in the NIR-II biowindow with improved penetration depth and low power density. More importantly, RCF with rough surfaces shows increased bacterial adhesion, thereby benefiting both CDT and PTT through effective interaction between RCF and bacteria. In vitro antibacterial experiments demonstrate a broad-spectrum synergistic antibacterial effect of RCF against Gram-negative Escherichia coli (E. coli), Gram-positive Staphylococcus aureus (S. aureus), and methicillin-resistant Staphylococcus aureus (MRSA). In addition, satisfactory biocompatibility makes RCF a promising antibacterial agent. Notably, the synergistic antibacterial performances in vivo could be achieved employing the rat wound model with MRSA infection. The current study proposes a facile strategy to construct antibacterial agents for practical antibacterial applications by the rational design of both composition and morphology. RCF with low power density NIR-II light responsive synergistic activity holds great potential in the effective treatment of drug-resistant bacterial infections.

Synergistic and On-Demand Release of Ag-AMPs Loaded on Porous Silicon Nanocarriers for Antibacteria and Wound Healing.

Due to the abuse of antibiotics, antimicrobial resistance is rapidly emerging and becoming a major global risk for public health. Thus, there is an urgent need for reducing the use of antibiotics, finding novel treatment approaches, and developing controllable release systems. In this work, a dual synergistic antibacterial platform with on-demand release ability based on silver nanoparticles (AgNPs) and antimicrobial peptide (AMP) coloaded porous silicon (PSi) was developed. The combination of AgNPs and AMPs (Tet-213, KRWWKWWRRC) exhibited an excellent synergistic antibacterial effect. As a carrier, porous silicon can efficiently load AgNPs and AMP under mild conditions and give the platform an on-demand release ability and a synergistic release effect. The AgNPs and AMP coloaded porous silicon microparticles (AgNPs-AMP@PSiMPs) exhibited an acid pH and reactive oxygen species (ROS)-stimulated release of silver ions (Ag+) and AMPs under bacterial infection conditions because of oxidation and desorption effects. Moreover, the release of the bactericide could be promoted by each other due to the interplay between AgNPs and Tet-213. In vitro antibacterial tests demonstrated that AgNPs-AMP@PSiMPs inherited the intrinsic properties and synergistic antibacterial efficiency of both bactericides. In addition, wound dressing loaded with AgNPs-AMP@PSiMPs showed outstanding in vivo bacteria-killing activity, accelerating wound-healing, and low biotoxicity in aStaphylococcus aureus-infected rat wound model. The present work demonstrated that PSiMPS might be an efficient platform for loading the antibiotic-free bactericide, which could synergistically and on-demand release to fight wound infection and promote wound healing.

Bioactive glass promotes the barrier functional behaviors of keratinocytes and improves the Re-epithelialization in wound healing in diabetic rats

Upon skin injury, re-epithelialization must be triggered promptly to restore the integrity and barrier function of the epidermis. However, this process is often delayed or interrupted in chronic wounds like diabetic foot ulcers. Considering that BG particles can activate multiple genes in various cells, herein, we hypothesized that bioactive glass (BG) might be able to modulate the barrier functional behaviors of keratinocytes. By measuring the transepithelial electrical resistance (TEER) and the paracellular tracer flux, we found the 58S-BG extracts substantially enhanced the barrier function of keratinocyte monolayers. The BG extracts might exert such effects by promoting the keratinocyte differentiation and the formation of tight junctions, as evidenced by the increased expression of critical differentiation markers (K10 and involucrin) and TJ protein claudin-1, as well as the altered subcellular location of four major TJ proteins (claudin-1, occludin, JAM-A, and ZO-1). Besides, the cell scratch assay showed that BG extracts induced the collective migration of keratinocytes, though they did not accelerate the migration rate compared to the control. The in vivo study using a diabetic rat wound model demonstrated that the BG extracts accelerated the process of re-epithelialization, stimulated keratinocyte differentiation, and promoted the formation of tight junctions in the newly regenerated epidermis. Our findings revealed the crucial effects of BGs on keratinocytes and highlighted its potential application for chronic wound healing by restoring the barrier function of the wounded skin effectively.

Photobiomodulation therapy was more effective than photobiomodulation plus arginine on accelerating wound healing in an animal model of delayed healing wound.

The combined and individual influences of photobiomodulation therapy (PBMT) and arginine on wound strength, stereological parameters, and gene expressions of some related growth factors in ischemic and delayed healing wounds in rats were analyzed. We divided 108 rats into six groups: control, lower energy density (LOW)-PBMT, 2% arginine ointment (Arg 2%), LOW-PBMT + Arg 2%, high energy density (HIGH)-PBMT, and HIGH-PBMT + Arg 2%. First, we generated an ischemic and delayed healing wound model in each rat. We examined wound strength, stereological parameters, and gene expressions of basic fibroblast growth factor (bFGF), vascular endothelial growth factor A (VEGF-A), and stromal cell-derived factor 1 (SDF-1) by quantitative real-time polymerase chain reaction (qRT-PCR). PBMT alone and PBMT + Arg 2% considerably increased wound strength compared to the control and Arg 2% groups during the inflammatory and proliferative steps of wound healing (p < 0.05). In these steps, PBMT alone significantly induced an anti-inflammatory effect and increased fibroblast counts; Arg 2% alone induced an inflammatory response (p < 0.05). Concurrently, PBMT and PBMT + Arg 2% significantly increased keratinocyte counts and volume of the new dermis (p < 0.05). At the remodeling step, the Arg 2% groups had significantly better wound strength than the other groups (p < 0.05). In this step, PBMT and PBMT + Arg 2% significantly decreased inflammation, and increased fibroblast counts, vascular length, and the volume of new epidermis and dermis compared to the control and Arg 2% groups (p < 0.05). In all cases of gene analysis, there were statistically better results in the PBMT and PBMT + Arg 2% groups compared with the Arg 2% and control groups (p < 0.05). The anti-inflammatory and repairing effects of PBMT on an ischemic and delayed healing wound model in rats were shown by significant improvements in wound strength, stereological parameters, and gene expressions of bFGF, VEGF-A, and SDF-1α.

Mesenchymal stem cells' seeded amniotic membrane as a tissue-engineered dressing for wound healing.

Different biomaterials have been used as biological dressing for wound regeneration. For many decades, human amniotic membrane graft (AM) has been widely applied for treating acute and chronic wounds. It has minimal toxicity and immunogenicity, supports mesenchymal cell in-growth, improves epidermal cell adherence and proliferation, and finally is inexpensive and readily available. Enrichment of tissue grafts with the stem cells is a new approach to improve their regenerative effects. This animal study aimed at investigating feasibility, safety, and efficacy of tissue-engineered dressings composed of AM and two different types of mesenchymal stem cells (MSCs) in the excisional wound model in rats. Human adipose-derived MSCs (ADMSCs) and placenta-derived MSCs (PLMSCs) were manufactured from the donated adipose and placenta tissues respectively. After cell characterization, MSCs were seeded on acellular AM (AAM) and cultivated for 5days. Excisional wound model was developed in 24 male Wistar rats that were randomly classified into four groups including control, AAM, ADMSCs + AAM, and PLMSCs + AAM (n = 6 in each group). Tissue-engineered constructs were applied, and photographs were taken on days 0, 7, and 14 for observing the wound healing rates. In days 7 and 14 post-treatment, three rats from each group were euthanized, and wound biopsies were harvested, and histopathologic studies were conducted. The results of wound closure rate, re-epithelialization, angiogenesis, and collagen remodeling demonstrated that in comparison with the control groups, the MSC-seeded AAMs had superior regenerative effects in excisional wound animal model. Between MSCs group, the PLMSCs showed better healing effect. Our data suggested that seeding of MSCs on AAM can boosts its regenerative effects in wound treatment. We also found that PLMSCs had superior regenerative effects to ADMSc in the rat model of excisional wound.

Injectable and Degradable PEG Hydrogel with Antibacterial Performance for Promoting Wound Healing.

Injectable and degradable PEG hydrogel was prepared via Michael-type addition between cross-linking monomer 4-arm-PEG-MAL and two cross-linkers of hydrolysis degradable PEG-diester-dithiol and non-degradable PEG-dithiol, and it had a porous structure with the uniform pore size. The biocompatibility assays in vitro indicated that PEG hydrogel had excellent biocompatibility and can be degraded naturally without leading to any negative impact on cells. The results of antibacterial experiments showed that PEG hydrogel can inhibit the growth of bacteria. Furthermore, the Cell Counting Kit-8 (CCK-8) assay, LIVE/DEAD cell staining, and scratch healing experiments proved that PEG hydrogel can promote cell proliferation and migration, which had been further confirmed in in vivo experiments on the rat wound models. All experimental results demonstrated that PEG hydrogel is an injectable antibacterial dressing, which can promote the process of wound healing and has great potential in the field of wound healing.

Effects of Freund's complete adjuvant on autophagy protein expression in rat tuberculous wound model

Objective: To explore the effects of Freund's complete adjuvant on autophagy protein expression in rat tuberculous wound model. Methods: The experimental research method was used. In the first batch, twelve 6-week-old male Sprague-Dawley (SD) rats were sensitized by subcutaneous injection of Freund's complete adjuvant into the hips. Three weeks later, the rats were infected with attenuated Bacille Calmette-Guérin (BCG) subcutaneously on both sides of the back spine. After establishing the tuberculosis wound rat model, according to the random number table (the same grouping method below), the rats were divided into 8 d infection group, 15 d infection group, 32 d infection group, and 43 d infection group, with 3 rats in each group, with continuous normal feeding to the corresponding days after infection. In the second batch, twenty-three 6-week-old male SD rats were divided into blank control group (n=3, normal feeding without any treatment), BCG alone group (n=5), BCG+ rapamycin group (n=6), BCG+ 3-methyladenine group (n=6), and BCG+ starvation group (n=3). The last 4 groups of rats were sensitized as before, and infected as before 1 week later. Rats in BCG alone group were fed normally without any treatment. Rats in BCG+ rapamycin group or BCG+ 3-methyladenine group were intraperitoneally injected with rapamycin or 3-methyladenine once every other day and fed normally. Rats in BCG+ starvation group were fasted for 48 hours after infection and then fed normally. All the rats in the first batch of 4 groups were sacrificed on the corresponding days after infection, and the tissue where the buttocks were injected with Freund's complete adjuvant was harvested; the tissue of rats in the second batch of BCG alone group, BCG+ rapamycin group, BCG+ 3-methyladenine group, and BCG+ starvation group were harvested the same as before 7 days after infection, and all the rats in blank control group were taken the same tissue at the same time point. Hematoxylin-eosin staining was performed to observe the structure and morphology of cells in the tissue harvested; immunohistochemistry was used to observe the protein expressions of Beclin-1, microtubule-associated protein 1 light chain 3B (LC3B) in the tissue harvested. Data were statistically analyzed with Kruskal-Wallis test and Bonferroni correction. Results: Inflammatory cell infiltration was observed in the tissue of rats where the Freund's complete adjuvant was injected in 8 d infection group, granuloma formation was seen in 15 d infection group, part of tissue cell necrosis was seen in 32 d infection group and 43 d infection group, and cell necrosis in 43 d infection group was worse than that in 32 d infection group. Seven days after infection, inflammatory cell infiltration was seen in the tissue of rats where the Freund's complete adjuvant was injected in BCG alone group, BCG+ rapamycin group, BCG+ 3-methyladenine group, and BCG+ starvation group, while regular arrangement of cells and no inflammatory cell infiltration were observed in blank control group. There were no statistically significant differences in the protein expressions of Beclin-1 or LC3B in the tissue of rats where the Freund's complete adjuvant was injected in 8 d infection group, 15 d infection group, 32 d infection group, and 43 d infection group (H=1.923, 5.821, P>0.05). Seven days after infection, the protein expressions of Beclin-1 and LC3B in the tissue of rats where the Freund's complete adjuvant was injected in blank control group, BCG alone group, BCG+ rapamycin group, BCG+ 3-methyladenine group, and BCG+ starvation group were respectively 0.325% (0.250%, 0.360%), 3.225% (1.340%, 3.987%), 4.823% (2.630%, 6.559%), 4.216% (1.790%, 5.969%), 1.765% (0.865%, 2.649%), and 0.301% (0.264%, 0.516%), 2.865% (1.455%, 5.768%), 1.033% (0.398%, 1.873%), 1.168% (0.429%, 1.907%), 0.655% (0.283%, 1.652%). The protein expression of Beclin-1 in the tissue of rats where the Freund's complete adjuvant was injected in BCG+ rapamycin group was significantly higher than that of blank control group (Z=4.796, P<0.05). The protein expression of LC3B in the tissue of rats where the Freund's complete adjuvant was injected in BCG alone group was significantly higher than that of blank control group (Z=4.953, P<0.05). Conclusions: Freund's complete adjuvant can enhance the expression levels of local tissue autophagy-related proteins Beclin-1 and LC3B in rat tuberculous wound model.

Preclinical assessment of stem of Nicotiana tabacum on excision wound model

Agro-waste material derived from N. tabacum has shown enormous potential antioxidant and antimicrobial activity. Hence in the present study, we investigated the wound healing efficacy of ethanolic extract of stem of Nicotiana tabacum on wistar rat model. Ethanolic extract prepared from defatted stem was to check various phytochemicals using spectrophotometric and chromatographic technique. The antioxidant potential was determined by FRAP and Reducing Power assay in extract. Cytotoxicity of extracts was determined using mouse fibroblast L929 cell lines by MTT assay. In vivo angiogenic activity was observed on chick chorioallantoic membrane (CAM) model by observing blood vessels formation and its branching. In vivo wound healing activity was observed on excision wounds in rat model by quantifying percentage of wound contraction, antioxidant activity and histopathology studies. From the present study, polyphenols, tannins and alkaloids were found to be determined in the ethanolic extract by means of spectrophotometric and chromatographic analysis against standards. Antioxidant assay revealed maximum antioxidant potential in ethanolic extract. Cytotoxic effect of extract has not been shown on L929 cell line. From CAM model, extract has shown growth of blood vessels formation at concentration of 480 µg/ml. Topical application of extracts on excision wounds, revealed wound healing activity i.e. 98.7% ± 0.002 on 14th day as well as enzymatic activity (SOD, CAT, GST) and non enzyme content (GSH and Lipid peroxidation) has been found to be high in granulated tissue. Hisopathological studies confirmed the re-epithelization in skin wounds. It can be concluded that stem of N. tabacum can be used as herbal remedy in wound healing process as a topical application.

RETRACTED: Healing potential of Spirulina platensis for skin wounds by modulating bFGF, VEGF, TGF-ß1 and α-SMA genes expression targeting angiogenesis and scar tissue formation in the rat model

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. The journal was alerted to an associated PubPeer post in which suspected duplicated features were identified within Figure 4 B1, and the histological image in Figure 3 A1 appears to have been previously published in another article, as detailed here: https://pubpeer.com/publications/E5658B7B735FF993AA795A5F14C086. The journal performed independent analysis and identified additional suspected image duplications between the images of mice in Figure 1 A+B and images of mice in Figure 6 A+B from Elbialy et al., BMC Veterinary Research (2020). The journal requested the authors provide an explanation to these concerns and associated raw data, but this request was not satisfactorily fulfilled. The Editor-in-Chief assessed the case and decided to retract the article.

Wound Healing Potential of Crocin and Safranal, Main Saffron (Crocus sativus L.), the Active Constituents in Excision Wound Model in Rats

Background: Saffron is traditionally suggested for wound healing in Persian medicine. It is investigated for wound healing effect in multiple studies with promising results. It is not examined that which ingredient of saffron contributes more to this effect. This study was aimed to evaluate and compare the wound healing potential of saffron and its active constituents, crocin, and safranal, in rats. Materials and Methods: Forty female adult rats with induced excision wounds were randomly divided into four groups to receive topical formulation of saffron, crocin, safranal, and placebo for seven days. The Wound area and histopathologic stage of wound healing were evaluated as outcome measures. Results: The wound area was significantly lower in treatment groups (saffron, crocin, and safranal) compared to the control group on day 7 of the intervention. Compared to the control group, the wound in all treated groups showed a decreased inflammatory response and more progression to the proliferation phase. The saffron group showed more advanced healing phase with complete epithelialization of the wound on day 7 of study when partial and no epithelialization was observed in safranal and crocin groups. Conclusion: The study showed the wound healing properties of both safranal and crocin with the slight superiority of safranal. However, saffron seems to be more potent in wound healing effect compared to safranal and crocin as its main active constituents. [GMJ.2021;10:e1900]

Wound Healing Potential of Crocin and Safranal, Main Saffron (Crocus sativus L.), the Active Constituents in Excision Wound Model in Rats

Background: Saffron is traditionally suggested for wound healing in Persian medicine. It is investigated for wound healing effect in multiple studies with promising results. It is not examined that which ingredient of saffron contributes more to this effect. This study was aimed to evaluate and compare the wound healing potential of saffron and its active constituents, crocin, and safranal, in rats. Materials and Methods: Forty female adult rats with induced excision wounds were randomly divided into four groups to receive topical formulation of saffron, crocin, safranal, and placebo for seven days. The Wound area and histopathologic stage of wound healing were evaluated as outcome measures. Results: The wound area was significantly lower in treatment groups (saffron, crocin, and safranal) compared to the control group on day 7 of the intervention. Compared to the control group, the wound in all treated groups showed a decreased inflammatory response and more progression to the proliferation phase. The saffron group showed more advanced healing phase with complete epithelialization of the wound on day 7 of study when partial and no epithelialization was observed in safranal and crocin groups. Conclusion: The study showed the wound healing properties of both safranal and crocin with the slight superiority of safranal. However, saffron seems to be more potent in wound healing effect compared to safranal and crocin as its main active constituents. [GMJ.2021;10:e1900]

Topical application of HA-g-TEMPO accelerates the acute wound healing via reducing reactive oxygen species (ROS) and promoting angiogenesis

During the occurring of cutaneous trauma, increasing oxidative stress response in wound site retards the progress of proliferation phase, impeding sequent efficient wound repair. At the same time, high-quality healing also requires adequate new blood vessels in order to furnish the wound site with a nutrient and oxygen-sufficient environment. Here we synthesized a novel hyaluronic acid (HA) material modified with a peroxidation inhibitor 2,2,6,6-tetramethylpiperidinyloxy (ATEMPO) for prevention of excessive reactive oxygen species (ROS) and promotion of angiogenesis after full-thickness skin excision in rats. Amines in ATEMPO attaching with carbonyls in HA chains was fabricated through N-acylation. The HA-g-TEMPO exerted a ROS-scavenging and angiogenesis-promoting function in vitro. In acute wound rat model, the wound closure efficacy was significantly improved to almost 55% at day 6 in comparison to 49% of HA, and wound sites in initial wound phase was also narrowed down sharply. Moreover, initially formed blood vessels were found in wound sites, further proved the angiogenesis-promoting function of HA-g-TEMPO. More interestingly, wound sites demonstrated an exciting regenerative healing effect which was characterized by marked skin appendages as well as reduced scarring. Therefore, this strategy showed a promising future that could be considered as a reliable and effective method to cutaneous wound healing.

Promising Antidiabetic and Wound Healing Activities of Forsskaolea tenacissima L. Aerial Parts

The aim of present study was to evaluate the antidiabetic activity of the total methanolic extract (TME) and different fractions of Forsskaolea tenacissima L. aerial parts with alloxan-induced diabetic rats and estimate its wound healing activity by excision wound model in rats as well as determine its toxicological activity by lethal dose 50 % (LD50). The ethyl acetate fraction showed a significant decrease in blood glucose level (36.00 %, P < 0.001) in comparison with glibenclamide (36.14 %, P < 0.001) as standard. The TME group showed marked increase in wound healing activity (97.9 %) compared with gentamycin standard group (96.8 %). The TME is considered safe due to its LD50, which was 7 g/kg body weight.

Reinwardtia indica: phytochemical screening and evaluation of wound healing activity of the extracts in experimental model rats.

Reinwardtia indica is traditionally used for wound healing. The main aim of this study was to evaluate the wound healing activity of leaves extracts of R. indica using the excision wound model in rats. The leaves of R. indica were collected from Gondrang, Chitwan, Nepal. Leaves were shade dried, extracted by double maceration and subjected to phytochemical screening. Then, the fusion method was used for the formulation of ointment and evaluated. Rats (n=24) were divided into four groups with 6 in each. Excision wound model was used, 2 cm diameter (314 mm2), 2 mm depth wound was created. The treatment was given daily topically to all groups and the % mean wound contraction rate was calculated on days 4, 8, 12 and 16. The result was analyzed statistically using Graph pad prism version 5. Phytochemical test revealed the presence of alkaloid, flavonoid, tannin, phenol, terpenoid, carbohydrate, etc. All the evaluation parameters showed satisfactory results. The extract of R. indica ointment (2% w/w and 5% w/w) increased the wound contraction rate day by day. The % means wound contraction rate, on day 12, (80% and 88%), and on day 16, (97% and 100%) and statistically significant difference was at p<0.0001. The R. indica extract ointment showed an increased wound contraction rate. So, in further R. indica could be used for commercial production of wound healing ointment.

Is traditional herbal mix composition effective on wound healing?

Objective: Wound healing is a dynamic process that includes biochemical and physiological phenomena. Studies confirm that plants are used in wound healing to a great extent. Antique oil (HBX 2371) has been produced as a traditional herbal mixed. This herbal mixture contains sesame oil, thyme oil, olive leaf, fig seed, grape seed, turmeric, and cinnamon. We evaluated traditional plant mixed oil ( Antique oil) for its wound-healing activity using an excision wound model in rats.&#x0D; Methods: The study used a preclinical, in vivo experimental, and analytical design. In the study, a total of 21 Sprague-Dawley rats, including 7 as experimental group, 7 as negative-control group, and 7 as positive-control group, were used. After the ischemic wound was created in experimental animals, the research data relating to the histochemical changes and biochemical parameters of the wound healing parameters were collected&#x0D; Results: A to research in experimental group fibroblast count, collagen density, fat cells, epithelization scores higher than the other groups and inflammatory cell density lower than the others. According to the results of the study, the highest TAC value (3.94 ± 0.21) was determined in the experimental group and results showed that antique oil administration decreased the TOC value.&#x0D; Conclusion: In conclusion, it was observed that antique oil prevented the wound changes induced by the incision, increased the repair of the epidermal and dermal structure in a short time, increased the antioxidant level, and decreased the oxidation level. Clinical studies are recommended.

In Vitro and In Vivo Evaluation of the Wound Healing Potential of the Extracts of Schinus molle L. (Anacardiaceae) Grown in Jordan

The aim of this study was to assess the wound healing potential of Schinus molle L. aqueous and ethanol extracts. First, the antimicrobial activity of Schinus molle extracts was tested against six microorganisms (Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus epidermidis, Enterococcus faecalis and Citrobacter freundii). The growth of Citrobacter freundii and Enterococcus faecalis was totally inhibited by the aqueous extract at the lowest tested concentration (1.56 mg/mL). Next, in vitro wound healing assays were performed using human fibroblast cells’ proliferation and scratch tests. Based on the obtained promising results, the aqueous extracts were further tested in an in vivo excision wound model in rats. Animals were treated with a hydrogel formula enriched with the plant aqueous extract in two different concentrations (2 % and 5 %). Re-epithelialization, fibrosis and neovascularization of the epidermis and sub-epidermal cells in the regenerated tissue was observed, accompanied by an increase in the tensile strength of the skin of the rats treated with the plant aqueous extract when compared to the negative control group. Our results strongly support the use of Schinus molle aqueous extracts in topical formulations to promote wound healing.

Evaluation of the wound-healing effect of an N-isopropenylimidazole zinc metal complex derivative on a linear skin wound model in rats

Evaluation of the wound-healing effect of an N-isopropenylimidazole zinc metal complex derivative on a linear skin wound model in rats

Photo-initiated enhanced antibacterial therapy using a non-covalent functionalized graphene oxide nanoplatform.

This study describes a novel antibacterial phototherapeutic platform for highly efficient healing of bacteria-infected wounds. It is based on the photodynamic and physical actions of a zinc tetraaminophthalocyanine-modified graphene oxide nanocomposite produced via non-covalent functionalization. The nanocomposite is positively charged and can easily capture negatively charged bacteria via electrostatic interactions. The antibacterial action is two-fold: (1) reactive oxygen species are produced by the phthalocyanine photosensitizer after short-term exposure to 680 nm light and (2) the graphene oxide can physically cut bacterial cell membranes. These enhanced activities can kill Gram-positive and Gram-negative bacteria at very low dosages. An ultrastructural examination indicates that this nanocomposite causes enormous damage to bacterial morphology and leakage of intracellular substances that lead to bacterial death. A rat wound model is used to demonstrate that the proposed phototherapeutic platform has low cytotoxicity and can promote rapid healing in bacteria-infected wounds. These results suggest that the integration of different antibacterial methods into a single nanotherapeutic platform is a promising strategy for anti-infective treatment.

Towards on the Mediators in Collagen Replacement: Effect of the Active Molecules into a Polymeric Biomaterial

Modulating healing factors could avoid or minimize some possible pathological processes in collagen deposition. The present study was aimed to evaluated the role of active biomolecules such as PDGF-BB and PRP loaded or not into polymeric biomaterial to seek potential mediators in types I and III collagen deposition and epithelization. The healing phases were investigated by using an in vivo full-thickness wound rat model. At zero, 3rd, 7th and 14th days after the experimental model, the size of the wound areas was photographed. The nanofibrous materials were biocompatible and did not cause any local adverse reaction and/or inflammation. On day 14 the wounds had healed almost 100% with better signs of healing, however there was no obvious difference in the wound contraction rates. At the end of 14 days, samples from the center of the lesion were collected when histological features and immunopositivity for collagen I and III expressions were assessed. There was no significant difference in the epithelization among the groups. Wounds treated with PRP and with PA-6/SOMA plus PDGF-BB had significantly lower amounts of type III collagen. The amounts of type I collagen did not have a statistically different deposition among the experimental groups. The association of PDGF-BB with PA-6/SOMA emerges as an alternative for topical application to unfavorable anatomical sites, suggesting that these associations may have a positive modulation on the process of accelerated healing remodeling.

Determination of wound healing activity of Shark liver oil using the excision wound model in Wistar rats

There are various promising preclinical models, such as in mice, wistar rats, rabbits and pigs, which can be utilized to initiate acute or chronic wounds. These can be persuaded by many distinctive techniques, with excision the most common. After determining a proper model for a study, investigators need to choose an appropriate and reproducible technique that will permit the monitoring of the wound improvement over time. In this study, the healing power of Shark Liver Oil Emulgel (SLO) in Wistar rats were analyzed by using the excision wound model. The shark liver oil was prepared as emulgel at a concentration of 5%,10% and 15%, respectively and both Standard drug(Povidone-Iodine Ointment USP 5% w/w-PI) and SLO is applied at a concentration of 1mg/mm2; Topically. The parameters integrated for the assessment of the effects of SLO were Relative body weight changes, wound area contraction in mm2, relative wound percentage and epithelialization time. Wound area contraction was measured on 1st, 3rd, 6th, 9th, 12th, 15th, 18th and 21st day. Wistar rats treated with SLO showed substantial variations in epithelialization period and improved wound contraction in the excision wound treatment as compared to disease control. The biochemical biomarkers like SOD(Superoxide dismutases), GSH(Reduced Glutathione)and LPO(Lipid peroxidase) in the treated group have shown a significant change in the improvement of wound healing. Histopathological studies and microscopic observations specify that the topical use of Shark liver oil Emulgel extensively improved wound contraction, collagenation and epithelialization with well-organized dermis devoid of inflammatory cells in contrast to disease control.