Rat Skin Research Articles

The Role of Vitamin A on the Histology of Skin of Adult Rats After Eposure to UVB

Background: long-term eposure of skin to sun (UV light) may produce different dermatological changes. The aim of this eperiment is to eplore the protective effects of oral vitamin A on skin subjected to UVB. Methods: twenty rats were separated into: group 1 (without UVB eposure), group 2 (eposed to single daily increasing dose of UVB for one week), group 3 (eposed to UVB with oral daily administration of vit A 10000 IU for one week), group 4 (received vit A for one week). The daily doses of UVB were respectively 0.24, 0.36, 0.48, 0.6, 0.72, 0.84 and 0.96 J/cm2. Skin samples were stained with hematoylin-eosin and Masson’s trichrome stains, in addition to Melan-A stain for melanocytes. Results: histopathological results in skin of group 2 demonstrated loss of normal architecture with increase in thickness of epidermis, hyperkeratosis and parakeratosis, moreover, skin sections detected increased number of inflammatory cells with damaged hair follicles. The basal layer shows an increase in mitotic division and necrosis, besides, epidermal edema and vascular congestion. Furthermore, collagen fibers were degraded. Immunohistochemical reaction revealed intense positive epression of Melan-A with increased proliferation and activity of melanocytes, while sections of groups 1 and 4 show normal healthy skin and negative Melan-A epression. In contrast, skin of group 3 reveals mild hyperkeratosis with normal keratin layer, in addition, the infiltration of inflammatory cells was dropped and hair follicles were preserved. Collagen bundles were slightly degraded with normal arrangement. Immunohistochemical results of this group show mild positive epression of Melan A. Conclusion: oral administration of vitamin A decreases the toic effect of UVB radiation on skin and reduces its induced pigmentation.

An Injectable Hydrogel with Ultrahigh Burst Pressure and Innate Antibacterial Activity for Emergency Hemostasis and Wound Repair.

Uncontrolled bleeding and wound infections following severe trauma pose significant challenges for existing tissue adhesives, primarily due to their weak wet adhesion, slow adhesion formation, cytotoxicity concerns, and lack of antibacterial properties. Herein, an injectable hydrogel (denoted as ES gel) with rapid, robust adhesive sealing and inherent antibacterial activity based on ε-polylysine and a poly(ethylene glycol) derivative is developed. The engineered hydrogel exhibits rapid gelation behavior, high mechanical strength, strong adhesion to various tissues, and can sustain an ultrahigh burst pressure of 450mmHg. It also presents excellent biocompatibility, biodegradability, antibacterial properties, and on-demand removability. Significantly improved hemostatic efficacy of ES gel compared to fibrin glue is demonstrated using various injury models in rats and rabbits. Remarkably, the adhesive hydrogel can effectively halt lethal non-compressible hemorrhages in visceral organs (liver, spleen, and heart) and femoral artery injury models in fully anticoagulated pigs. Furthermore, the hydrogel outperforms commercial products in sutureless wound closure and repair in the rat liver defect, skin incision, and infected full-thickness skin wound models. Overall, this study highlights the promising clinical applications of ES gel for managing uncontrolled hemorrhage, sutureless wound closure, and infected wound repair.

In vitro evaluation of ethyl cellulose and polyvinyl pyrrolidone composite nanofibers for transdermal delivery of diclofenac diethylamine

Non-steroidal anti-inflammatory drugs (NSAIDs) are the most prominent painkiller and anti-inflammatory drugs with gastrointestinal (GI) adverse effects. Transdermal drug delivery systems (TDDS) could overcome GI adverse effects associated with oral ingestion of NSAIDs as well as maintaining a prolonged release of the drug. The main aim of this study was to prepare and investigate diclofenac diethylamine (DDA) loaded nanofibers made of ethyl cellulose (EC) and polyvinyl pyrrolidone K90 (PVP) using electrospinning. The impact of penetration enhancers such as nerolidol and farnesol on release profiles through cellophane membranes and other characteristics of nanofibers were also investigated. Based on release studies, some formulations were selected for release examination through rate skin using Franz diffusion cells. To gain insight about potential interactions between drug and polymers FTIR, DSC, and XRD analyses were performed. Morphology examination was also conducted using scanning electron microscopy (SEM). Morphology studies showed that nanofibers made of EC only are greater in the mean diameter than other nanofibers while other formulations were not significantly different from each other regardless of the presence of penetration enhancers. EC nanofibers had the lowest elastic modulus and tensile strength and most elongation at break which makes them the least tough and most flexible nanofibers among all the formulations. The addition of PVP increased the toughness and decreased the flexibility of nanofibers. The addition of nerolidol did not alter the mechanical properties of nanofibers significantly, while the addition of farnesol increased elastic modulus, tensile strength, and elongation at break significantly in a concentration-dependent manner. EC nanofibers had the lowest release rate and lowest total cumulative release content while the addition of PVP significantly improved both of these features. In release studies through cellophane membrane, the addition of 5 % of penetration enhancer slightly increased the release rate while did not significantly alter cumulative release while the addition of 10 % farnesol notably increased the release rate and total cumulative released content. Release studies through rat skin were in accordance with cellophane membrane studies and the formulation with 10 % farnesol had the most release rate and total cumulative release and these findings confirm the positive effect of penetration enhancers. DSC thermogram showed an amorphous state of the drug in fibres and this was supported by XRD results. The FTIR results confirmed that no chemical interaction between the drug and other formulation components has occurred and no new compounds have been formed. Based on these results, the utilization of DDA-loaded PVP and EC nanofibers in conjunction with a penetration enhancer showed significant potential for application in transdermal patches.

Preparation, Characterization, and Skin Permeation Evaluation of Naproxen Microemulsions for Transdermal Delivery

: Microemulsions (MEs) are considered for preparing drug delivery carriers, especially transdermal vehicles. Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used to manage chronic and acute pain and inflammatory diseases. However, NSAIDs have drawbacks such as gastrointestinal tract disorders and poor pharmacokinetic properties for oral administration. To address these issues, we evaluated the potential of ME as a transdermal system for locally delivering naproxen (NPX) as an NSAIDs model (NPX-MEs). Phase diagrams were constructed for MEs composed of tween 80, span 80, and propylene glycol (PG) as surfactant (S)/cosurfactant (CS), transcutol® P (TRC-P), and LabrafacTM PG as oil. The final concentration of NPX in MEs was 1% (w/v). The MEs were analyzed for particle size, refractive index, and viscosity. In vitro permeability studies of NPX-MEs were conducted using Franz diffusion cells on rat skin samples. Additionally, the effects of Eucalyptus oil (EU oil), oleic acid (OLA), and TRC-P as enhancers on the skin permeation of NPX were investigated. The particle size and viscosity values of the NPX-MEs ranged from 7.05 ± 0.03 to 79.56 ± 0.58 nm and 222.4 ± 0.87 to 681.13 ± 1.97, respectively. The optimal formulation, ME-3, consisted of 20% oil, 10% water, and 70% S/C phases. The skin permeation rates of NPX from ME-3 were higher than those of other formulations (Dapp = 1.36 ± 0.616, ERD=527.989 ± 313.627) with a lower lag time. Additionally, OLA-treated skin showed the highest transdermal permeation rate (ERD = 75.55 ± 23.532). Based on these results, the formulated NPX-ME may be a desirable carrier for transdermal delivery compared to traditional formulations, potentially reducing side effects and improving the therapeutic efficacy of NPX.

Doxycycline monohydrate and azelaic acid Co-loaded nanoemulgel for the treatment of facial rosacea: In vitro and In vivo evaluation

Nanoemulgel have gained importance as topical delivery systems because of their potential to incorporate hydrophilic and lipophilic drugs simultaneously like emulsions and improved stability and spreadability like gels. Therefore, the current research was aimed to prepare, optimize, and evaluate the combined therapeutic efficacy of doxycycline monohydrate (DOX.H2O) and azelaic acid (AZL) loaded into a nanoemulgel (NE) against facial rosacea. The nanoemulsion was prepared via phase inversion low energy emulsification method by solubilizing DOX.H2O in peppermint oil and AZL in deionized water. The formulation was optimized using Design Expert 13. The optimized nanoemulsion has a particle size of 210.6 nm, a PDI of 0.234 and a zeta potential of −15.1 mV. SEM observations revealed the spherical morphology of oil globules, whereas FTIR results confirmed that no chemical interaction among the ingredients took place. The in vitro release study showed the burst release of 82.1 % AZL and 48.1 % release of DOX.H2O from the optimized DOX-AZL co-loaded NE in 6 h. The ex vivo permeation profile showed a minimum permeation of DOX.H2O and AZL across rat skin. Croton oil induced inflammation in mice ear confirmed the therapeutic efficacy of the prepared NE against facial rosacea. Considering the results obtained herein, the developed NE could enhance the safety and efficacy of the combination therapy against facial rosacea.

Chitosan films synthesized via thiol-ene click chemistry: Toward safe and versatile platforms for packaging, cosmetics and biomedical applications

The first synthesis of chitosan-based films using bio-based reticulating agents via Thiol-Michael addition click reaction was described, along with their successful application in packaging, cosmetics, and biomedical fields. The impact of chitosan (CS) concentration and the type of synthesized bio-sourced biacids (GD) and triacids (GT and TT) on the physicochemical properties of these films were assessed. Films prepared with dibasic and tribasic acids (4%-CS) demonstrated superior mechanical properties and lower solubility compared to those containing 2% CS. The incorporation of the bio-sourced GD, GT, and TT acids led to a reduction of 53%, 60% and 60.4%, respectively, in the water vapor permeability (WVP) of 4% CS-based films compared to the control film. Remarkably, CS-TT-4% films exhibited the highest mechanical strength (TS), elongation at break (%E), elasticity, water vapor, and light barrier properties. Cytotoxicity tests performed on the NIH 3T3 fibroblast cell line showed that CS-GD-4% films exhibited the highest compatibility. The efficiency of these films as drug carriers was tested with challenging anticancer and cosmetic molecules, particularly etoposide (ETP) caffeine (Caf), showing very high drug loading with a progressive release of less than 20% after 72h of incubation. Moreover, ex-vivo permeation studies in rat skin revealed that the percutaneous absorption of Caf is significantly increased by a factor of 5.5 compared to that of CS-GD-4%-Caf films with no significant histological alterations of skin layers. Altogether, this work evidences the most suitable casting solvent for developing safe chitosan films, promising their potential applications in the cosmetic and biomedical fields.

Topical gel formulations as potential dermal delivery carriers for green-synthesized zinc oxide nanoparticles.

This study aimed to incorporate green-synthesized zinc oxide nanoparticles (ZnO NPs), functionalized with polyethylene glycol (PEG) and linked to doxorubicin (DOX), into various topical gel formulations (hydrogel, oleogel, and bigel) to enhance their dermal delivery. The ZnO NPs were produced using the aqueous extract of the root hair of Phoenix dactylifera. The optimized green-synthesized ZnO NPs, PEGylated and conjugated to DOX, demonstrated a particle size below 100nm, low polydispersity index, and zeta potential between - 11 and - 19 mV. The UV-Vis spectroscopy analysis confirmed characteristic absorption peaks at 351 and 545nm for ZnO and DOX, respectively. The transmission electron microscope (TEM) images revealed well-dispersed spherical nanoparticles without aggregation. Additionally, ZnO NPs-loaded gels exhibited uniformity, cohesion, no phase separation, pseudoplastic flow, and viscoelastic properties. The in vitro release studies showed that DOX-PEG-ZnO NPs hydrogel released 99.5% of DOX after 5h of starting the release. Moreover, the penetration of DOX-PEG-ZnO NPs through excised rat skin was visualized by TEM. In conclusion, the hydrogel formulation containing green-synthesized DOX-PEG-ZnO NPs holds great promise for dermal administration in skin cancer treatment. Furthermore, the release rate and skin penetration of DOX from gels were varied based on the type of gel matrix and corroborated with their corresponding rheological properties.

Astaxanthin Expedites the Healing of Acute Skin Wounds in Rats by Facilitating M2 Macrophage Polarization and Enhancing Collagen Secretion.

Facilitating the healing process of skin post-trauma is crucial for minimizing infection risks and reinstating normal tissue functionality. While past studies have established astaxanthin (ASX) as an effective compound in promoting wound healing, the precise mechanism of its action remains unclear. Consequently, the objective of this study was to explore the impact of ASX on the acute wound healing of rat skin by modulating macrophage polarization. Eighteen male SD rats were randomly assigned to control, dimethylsulfoxide (DMSO), and ASX groups. Acute skin wounds were induced in the rats, and the effects of different treatments on wound area and healing were assessed. Hematoxylin-eosin (H&E) staining was employed to detect histopathological changes in the skin, while Masson staining was utilized to observe collagen expression. Immunohistochemistry was conducted to identify clusters of differentiation (CD) 206 macrophages in the tissues. Furthermore, enzyme-linked immunosorbent assay (ELISA) was used to measure the levels of inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin (IL)-6, IL-8, IL-10, IL-4, and IL-13. The expression of inducible nitric oxide synthase (iNOS), arginase (Arg)-1, and mannose receptor C-type 1 (Mrc1) proteins in the injured skin of rats was assessed through Western blot analysis. On postoperative days 7 and 14, the ASX treatment demonstrated notable reductions in inflammatory cell infiltration and inflammatory cytokine expression when compared to the Control and DMSO groups. This was accompanied by evident improvements in the pathological changes in skin tissue, characterized by the regeneration of new epidermis, dermal repair, and increased thickness of granulation, contributing to enhanced scar formation. Furthermore, ASX therapy exhibited an upregulation in the expression levels of collagen I and collagen III, along with markers indicative of M2 macrophages. These findings collectively signify the accelerated progression of wound healing attributed to ASX intervention. In summary, these findings collectively indicate that ASX facilitates the healing of rat skin wounds by suppressing inflammatory responses and fostering M2 macrophage polarization. Consequently, ASX holds promise as a potentially effective drug for the treatment of skin wounds.

Transcutaneous Delivery of Dexamethasone Sodium Phosphate Via Microneedle-Assisted Iontophoretic Enhancement - A Potential Therapeutic Option for Inflammatory Disorders.

This study aimed to fabricate dexamethasone sodium phosphate loaded microneedle arrays (MNA) and investigate their efficiency in combination with iontophoresis for the treatment of hind paw oedema in rats. Drug loaded polyvinyl alcohol, polyvinyl pyrrolidone and D-sorbitol-based MNA11 were fabricated by vacuum micromolding. Physicochemical, morphological, thermal, in-silico, in-vitro insertion ability (on parafilm) and drug release studies were performed. Ex-vivo permeation, in-vivo insertion and anti-inflammatory studies were performed in combination with iontophoresis. MNA11 displayed sharp-tipped projections and acceptable physicochemical features. Differential scanning calorimetry results indicated that drug loaded MNA11 were amorphous solids. Drug interacted with PVP and PVA predominately via hydrogen bonding. Parafilm displayed conspicuously engraved complementary structure of MNA11. Within 60min, 91.50 ± 3.1% drug released from MNA11. A significantly higher i.e., 95.06 ± 2.5% permeation of drug was observed rapidly (within 60min) from MNA11-iontophoresis combination than MNA11 i.e., 84.07 ± 3.5% within 240min. Rat skin treated using MNA11 and MNA11-iontophoresis showed disruptions / microchannels in the epidermis without any damage to underlying anatomical structures. MNA11-iontophoresis combination led to significant reduction (83.02 ± 3.9%) in paw oedema as compared to MNA11 alone (72.55 ± 4.1%). MNA11-iontophoresis combination can act as a promising candidate to deliver drugs transcutaneously for treating inflammatory diseases.

Preparation of recombinant mussel mucin Mfp-3P and its promotion of wound healing

To investigate the role of recombinant mussel mucin in wound healing, we aimed to prepare this mucin using Pichia pastoris as the host microbe. Our method involved constructing a genetically engineered strain of P. pastoris that expressed a fusion protein consisting of Mfp-3 and preCol-P peptide segments of mussel. After fermentation and purification, we obtained a pure recombinant mussel mucin product. We then conducted experiments to evaluate its effect at both the cellular and animal levels. At the cellular level, we examined its impact on the proliferation and migration of mouse fibroblast L929. At the animal level, we assessed its ability to promote wound healing after full-layer skin resection in rats. Our results showed that the recombinant mussel mucin protein has a content of 90.28% and a purity of 96.49%. The content of 3,4-dihydroxyphenylalanine (DOPA) was 0.73 wt%, and the endotoxin content was less than 0.5 EU/mg. Importantly, the recombinant mussel mucin protein significantly promoted both the migration and proliferation of mouse fibroblast, as well as the wound healing in rat skin. In conclusion, our findings demonstrate that recombinant mussel mucin has the potential to promote wound healing and can be considered a promising medical biomaterial.

Resveratrol-coated chitosan mats promote angiogenesis for enhanced wound healing in animal model.

Growing incidences of chronic wounds recommend the development of optimal therapeutic wound dressings. Electrospun nanofibers have been considered to show potential wound healing properties when accompanied by other wound dressing materials. This study aimed to explore the potential role of Chitosan (CS) nanofibrous mats coated with resveratrol (RS) as an antioxidant and pro-angiogenic agent in rat models of skin wound healing. Electrospun chitosan/polyethylene oxide (PEO) nanofibers were prepared using electrospinning technology and coated by 0.05 and 0.1 mg.ml resveratrol named as (CS/RS 0.05) and (CS/RS 0.1), respectively. The scaffolds were characterized physiochemically such as invitro release study, TGA, FTIR spectroscopy analysis, biodegradability, and human dermal fibroblast seeding assay. The scaffold was subsequently used invivo as a skin substitute on a rat skin wound model. In vitro tests revealed that all scaffolds promoted cell adhesion and proliferation. However, more cell viability was observed in CS/RS 0.1 scaffold. The biocompatibility of the scaffolds was validated by MTT assay, and the results did not show any toxic effects on human dermal fibroblasts. It was observed that RS-coated scaffolds had the ability to release RS in a controlled manner. In invivo tests CS/RS 0.1 scaffold had the greatest impact on the healing process by improving the neodermis formation and modulated inflammation in wound granulation tissue. Histological analysis revealed enhanced vascular endothelial growth factor expression, epithelialization and increased depth of wound granulation tissue. The RS-coated CS/PEO nanofibrous scaffold accelerates wound healing and may be useful as a dressing for cell transfer and clinical skin regeneration.

Intradermal Lactate Monitoring Based on a Microneedle Sensor Patch for Enhanced In Vivo Accuracy.

Lactate is an important diagnostic and prognostic biomarker of several human pathological conditions, such as sepsis, malaria, and dengue fever. Unfortunately, due to the lack of reliable analytical decentralized platforms, the determination of lactate yet relies on discrete blood-based assays, which are invasive and inefficient and may cause tension and pain in the patient. Herein, we demonstrate the potential of a fully integrated microneedle (MN) sensing system for the minimally invasive transdermal detection of lactate in an interstitial fluid (ISF). The originality of this analytical technology relies on: (i) a strategy to provide a uniform coating of a doped polymer-based membrane as a diffusion-limiting layer on the MN structure, optimized to perform full-range lactate detection in the ISF (linear range of response: 0.25-35 mM, 30 s assay time, 8 h operation), (ii) double validation of ex vivo and in vivo results based on ISF and blood measurements in rats, (iii) monitoring of lactate level fluctuations under the administration of anesthesia to mimic bedside clinical scenarios, and (iv) in-house design and fabrication of a fully integrated and portable sensing device in the form of a wearable patch including a custom application and user-friendly interface in a smartphone for the rapid, routine, continuous, and real-time lactate monitoring. The main analytical merits of the lactate MN sensor include appropriate selectivity, reversibility, stability, and durability by using a two-electrode amperometric readout. The ex-vivo testing of the MN patch of preconditioned rat skin pieces and euthanized rats successfully demonstrated the accuracy in measuring lactate levels. The in vivo measurements suggested the existence of a positive correlation between ISF and blood lactate when a lag time of 10 min is considered (Pearson's coefficient = 0.85, mean difference = 0.08 mM). The developed MN-based platform offers distinct advantages over noncontinuous blood sampling in a wide range of contexts, especially where access to laboratory services is limited or blood sampling is not suitable. Implementation of the wearable patch in healthcare could envision personalized medicine in a variety of clinical settings.

Biofriendly resveratrol loaded glycerosomal nanovesicles improve wound healing in chronic diabetic foot ulcers: In-vitro &in-vivo efficacy evaluation

Chronic diabetic foot ulcers (CDFUs) are complex pathological processes involving persistent inflammation, significantly impacting a patient's quality of life. Resveratrol (RES), recognized for its potent antioxidant and anti-inflammatory properties, faces challenges regarding its permeability. This study aimed to develop Resveratrol glycerosomal nanovesicles (RES-GLY-NVs) for topical application to enhance skin permeation. The optimized formulation was integrated into a 2 % HPMC gel and subjected to comprehensive physicochemical characterization, skin deposition, in vitro release, microbiological, antioxidant, and in vivo assessments. Results revealed RES-GLY-NVs with particle size ranging from 82.19 ± 6.51 nm to 145.70 ± 1.39 nm with PDI less than 0.5, encapsulation efficacy ranging from 89.14 ± 1.39 % to 96.09 ± 2.13 % and a zeta potential ranging from −27.93 ± 6.47 mV to −49.33 ± 1.89 mV. The release profile of RES was obviously ranging from % 54.40 ± 1.71 to 77.47 ± 0.54 % after 8 h. In vitro cell assessment revealed that RES-GLY-NVs have no cytotoxicity on normal cells. The optimized RES-GLY-NVs-HPMC gel displayed pseudoplastic rheological behavior and significantly enhanced RES flux and permeability through excised rat skin compared to plain gel. The In vivo study and histological evaluation of diabetic rats ensured that RES-GLY-NVs-HPMC gel acts as a more effective healing adjunct compared to free RES and conventional therapy. These findings encourage the utilization of RES-GLY-NVs-HPMC gel as a wound-healing drug delivery system in chronic diabetes-related wounds and ulcers.

Tissue Regeneration and Remodeling in Rat Models after Application of Hypericum perforatum L. Extract-Loaded Bigels.

The wound-healing effect of St. John's Wort (SJW) is mainly attributed to hyperforin (HP), but its low stability restricts its topical administration. This study investigates how "free" HP-rich SJW extract (incorporated into a bigel; B/SJW) and extract "protected" by nanostructured lipid carriers (also included in a biphasic semisolid; B/NLC-SJW) affect tissue regeneration in a rat skin excision wound model. Wound diameter, histological changes, and tissue gene expression levels of fibronectin (Fn), matrix metalloproteinase 8 (MMP8), and tumor necrosis factor-alpha (TNF-α) were employed to quantify the healing progress. A significant wound size reduction was achieved after applying both extract-containing semisolids, but after a 21-day application period, the smallest wound size was observed in the B/NLC-SJW-treated animals. However, the inflammatory response was affected more favorably by the bigel containing the "free" SJW extract, as evidenced by histological studies. Moreover, after the application of B/SJW, the expression of Fn, MMP8, and TNF-α was significantly higher than in the positive control. In conclusion, both bigel formulations exhibited beneficial effects on wound healing in rat skin, but B/SJW affected skin restoration processes in a comprehensive and more efficient way.

Decontamination of Actinide-contaminated Injured Skin with Ca-DTPA Products Using an Ex Vivo Rat Skin Model.

Skin contamination by α-emitting actinides such as plutonium and americium is a risk for workers during nuclear fuel production and reactor decommissioning. Decontamination of skin is an important medical countermeasure to limit potential internal contamination, particularly in the case of injured skin. Current recommendations include undressing of the victim followed by skin washing using soap or chelating agents, such as diethylene triamine pentaacetic acid (DTPA). The goal of the present work is to assess the efficacy of a novel Ca-DTPA loaded gel to decontaminate injured skin exposed to plutonium or americium as compared to recommended treatments. For decontaminant testing on injured skin, whole body skin was obtained from euthanized rats and lesions created using a metallic brush. Delimited test areas were contaminated with plutonium or americium solutions of known properties. Various protocols were tested including time before contamination, duration of gel application, washing steps, as well as the concomitant addition or not of dressings. Activity was measured in each decontamination product and in skin. Data indicate that healthy skin was easier to decontaminate than damaged skin. On injured skin, we demonstrated an increased decontamination efficacy of the Ca-DTPA gel formulation as compared to the solution. Importantly, gel application alone was effective, and further gel applications could be used for residual activity.

Bio-friendly oleic acid-based ufasomal topical gel of rosuvastatin for diabetic wound healing: In-vitro, ex-Vivo, and in-Vivo evaluation

This study aimed to develop bio-friendly and biodegradable oleic acid-based ufasomes coated with chitosan for topical delivery of rosuvastatin for diabetic wound healing. Rosuvastatin was chosen as a suitable candidate due to its wound healing properties. Thin film hydration technique was implemented for the preparation of ufasomes at various concentrations of oleic acid. The most promising formulation (UF 5) was coated with chitosan. The effect of oleic acid and chitosan concentrations on vesicle Size, zeta-potential, polydispersity index, entrapment efficiency, and in-vitro drug release study was assessed. Optimum chitosan-coated ufasomal dispersion (CUF 3) was subjected to further characterizations, such as FT-IR, TEM, in-vitro release, broth microdilution susceptibility test, the effect of storage, ex-vivo skin permeability study, and wound healing efficiency in rats. Finally, CUF 3 was incorporated into chitosan gel base and examined for wound healing efficiency in rats. Uncoated ufasomal dispersion (UF 5) possessed the smallest vesicle Size (149.6 nm), the highest entrapment efficiency (79.48 %), an optimum zeta-potential (−35.78 mv), with polydispersity index of 0.18. FT-IR of coated ufasomes (CUF 3) reflected the effective coating of chitosan on the surface of ufasomes which coincided with the TEM image. Similar release profiles of UF 5 and CUF 3 were observed after 4 h of dissolution due to chitosan coating surrounding ufasomes. The cumulative percent of drug permeated across rat skin after 24 h for CUF 3 dispersion, and CUF 3 in chitosan gel were 11.21 % and 10.48 %, respectively, in comparison to 2.97 % in case of control gel. This was confirmed from the results of flux and permeability coefficient. A maximum skin retention and a controlled release effect with a reduced risk of systemic absorption of rosuvastatin were attained by CUF 3 in chitosan gel. Rosuvastatin encapsulated in ufasomal vesicles augmented the antimicrobial activity against Gram-negative and Gram-positive bacteria. A remarkable wound healing of CUF 3 in chitosan gel was confirmed by morphological and histopathological studies. Oleic acid-based ufasomes coated with chitosan could be a promising bio-friendly carrier for rosuvastatin to obtain a triple effect formulation for diabetic wound healing.

Propellant Free Pressurized Spray System of Etodolac to Manage Acute Pain Conditions: In Vitro and In Vivo Evaluation.

This study aimed to develop a propellant-free topical spray formulation of Etodolac (BCS-II), a potent NSAID, which could be beneficial in the medical field for the effective treatment of pain and inflammation conditions. The developed novel propellant-free spray formulation is user-friendly, cost-effective, propellant-free, eco-friendly, enhances the penetration of Etodolac through the skin, and has a quick onset of action.Various formulations were developed by adjusting the concentrations of different components, including lecithin, buffering agents, film-forming agents, plasticizers, and permeation enhancers. The prepared propellant-free spray formulations were then extensively characterized and evaluated through various in vitro, ex vivo, and in vivo parameters. The optimized formulation exhibits an average shot weight of 0.24 ± 0.30ml and an average drug content or content uniformity of 87.3 ± 1.01% per spray. Additionally, the optimized formulation exhibits an evaporation time of 3 ± 0.24min. The skin permeation study demonstrated that the permeability coefficients of the optimized spray formulation were 21.42cm/h for rat skin, 13.64cm/h for mice skin, and 18.97cm/h for the Strat-M membrane. When assessing its potential for drug deposition using rat skin, mice skin, and the Strat-M membrane, the enhancement ratios for the optimized formulation were 1.88, 2.46, and 1.92, respectively against pure drug solution. The findings from our study suggest that the propellant-free Etodolac spray is a reliable and safe topical formulation. It demonstrates enhanced skin deposition, and improved effectiveness, and is free from any skin irritation concerns.

Facile Solvent-Free Fabrication of All-Small-Molecule Supramolecular Photothermal Bioadhesive for Sutureless Wound Closure.

Achieving underwater adhesion possesses a significant challenge, primarily due to the presence of interfacial water, which restricts the potential applications of adhesives. In this study, we present a straightforward and environmentally friendly one-pot approach for synthesizing a solvent-free supramolecular TPFe bioadhesive composed of thioctic acid, proanthocyanidins, and FeCl3. The bioadhesive exhibits excellent biocompatibility and photothermal antibacterial properties and demonstrates effective adhesion on various substrates in both wet and dry environments. Importantly, the adhesive strength of this bioadhesive on steel exceeds 1.2 MPa and that on porcine skin exceeds 100 kPa, which is greater than the adhesive strength of most reported bioadhesives. In addition, the bioadhesive exhibits the ability to effectively halt bleeding, close wounds promptly, and promote wound healing in the rat skin wound model. Therefore, the TPFe bioadhesive has potential as a medical bioadhesive for halting bleeding quickly and promoting wound healing in the biomedical field. This study provides a new idea for the development of bioadhesives with firm wet adhesion.

Spatiotemporal modulation of immune microenvironment via composite hydrogel brakes for diabetic wound healing

Uncontrolled programmed polarization of macrophages plays an important role in chronic diabetic wound healing. Therefore, correcting programmed macrophage polarization while inducing new tissue remodelling through materials and preventing scar formation is desirable. Herein, a composite hydrogel brake that enables spatiotemporal regulation of the immune microenvironment was constructed to promote skin tissue regeneration. The system was based on thiolated hyaluronic acid to reshape the programmed polarization of macrophages, methacrylate gelatin as a mechanical support, and poly (L-lactic acid) nanoparticles loaded with TGF-β receptor antagonists to inhibit scar formation. Notably, the composite hydrogel acts as a double brake: in the early stage, self-induced M2-type polarization is achieved with the help of thiols; the TNF and NLRP signalling pathways are downregulated; and the immune microenvironment is regulated. During tissue remodeling, the long-term biological effect of TGF-β secretion by M2-type macrophages is interrupted by the slow release of antagonists, which inhibits excessive collagen deposition and prevents scar formation. The dual effect of restraint on reprogramming macrophage polarization and inhibiting scar formation was further confirmed in a diabetic rat skin defect model. Therefore, based on the immunological mechanism, a composite hydrogel brake was specifically designed to regulate the immune microenvironment, induce new tissue remodelling, and provide a promising clinical strategy for treating chronic diabetic wounds.

Nanoemulsion‐laden poly(vinyl) alcohol hydrogel films for transdermal delivery of carbamazepine

AbstractThere is an unmet demand for transdermal devices that can deliver large dose of medications through the skin. Herein, nanoemulsion‐based poly(vinyl alcohol) (PVA) transdermal hydrogel films were developed for the high‐dose anti‐epileptic drug carbamazepine. A stable nanoemulsion was created with almond oil, Tween 60, and amphiphilic locust bean gum. The nanoemulsion had a hydrodynamic diameter of 251 nm, a polydispersity of 10.3%, and a zeta potential of −51.2 mV. Carbamazepine‐loaded nanoemulsion was blended with carbamazepine‐free PVA dispersion and casted into films. To accommodate a high dose, carbamazepine‐loaded nanoemulsion was trapped in a PVA dispersion containing carbamazepine to create transdermal films. The physicochemical characteristics and drug penetration characteristics of the produced films were compared. Both films had the uniform thickness, weight, and drug content. The folding endurance was found to be greater than 700 in both cases. Water vapor permeability decreased when carbamazepine was added to almond oil as well as polymer dispersion. FESEM pictures revealed a waxy paper‐like appearance for the PVA hydrogel film with dual drug‐reservoirs. FTIR spectra assessment revealed a hydrogen bonding interaction between PVA and carbamazepine. X‐ray diffraction examination revealed that the film contained an amorphous dispersion of carbamazepine. Dual carbamazepine reservoir‐based films outperformed single nanoemulsion drug reservoir‐based films in terms of drug flux through excised rat skin by 3.2 times. The in vitro skin permeation findings corresponded well to zero order kinetic models. Overall, this study showed that a high‐dose drug could be placed on nanoemulsion‐based transdermal PVA hydrogel films, resulting in improved skin permeability.Highlights Nanoemulsion was stable at almond oil:Tween 60/modified gum ratio of 5:5. Loading of high dose carbamazepine in nanoemulsion‐PVA transdermal films. Film of dual carbamazepine reservoir showed low water vapor permeation, moisture retention. Flux of carbamazepine from films improved three times through excised rat skin.