Paclitaxel skin delivery by micelles-embedded Carbopol 940 hydrogel for local therapy of melanoma

Design of nanosystems for melanoma treatment

Melanoma is a prevalent and concerning form of skin cancer affecting millions of individuals worldwide. Unfortunately, traditional treatments can be invasive and painful, prompting the need for alternative therapies with improved efficacy and patient outcomes. Nanosystems offer a promising solution to these obstacles through the rational design of nanoparticles (NPs) which are structured into nanocomposite forms, offering efficient approaches to cancer treatment procedures. A range of NPs consisting of polymeric, metallic and metal oxide, carbon-based, and virus-like NPs have been studied for their potential in treating skin cancer. This review summarizes the latest developments in functional nanosystems aimed at enhancing melanoma treatment. The fundamentals of these nanosystems, including NPs and the creation of various functional nanosystem types, facilitating melanoma treatment are introduced. Then, the advances in the applications of functional nanosystems for melanoma treatment are summarized, outlining both their benefits and the challenges encountered in implementing nanosystem therapies.

Paclitaxel-loaded elastic liposomes synthesised by microfluidics technique for enhance transdermal delivery

The inherent flexibility of elastic liposomes (EL) allows them to penetrate the small skin pores and reach the dermal region, making them an optimum candidate for topical drug delivery. Loading chemotherapy in ELs could improve chemotherapy's topical delivery and localise its effect on skin carcinogenic tissues. Chemotherapy-loaded EL can overcome the limitations of conventional administration of chemotherapies and control the distribution to specific areas of the skin. In the current studies, Paclitaxel was utilised to develop Paclitaxel-loaded EL. As an alternative to the conventional manufacturing methods of EL, this study is one of the novel investigations utilising microfluidic systems to examine the potential to enhance and optimise the quality of Els by the microfluidics method. The primary aim was to achieve EL with a size of < 200 nm, high homogeneity, high encapsulation efficiency, and good stability. A phospholipid (DOPC) combined with neutral and anionic edge activators (Tween 80 and sodium taurocholate hydrate) at various lipid-to-edge activator ratios, was used for the manufacturing of the ELs. A preliminary study was performed to study the size, polydispersity (PDI), and stability to determine the optimum microfluidic parameters and lipid-to-edge activator for paclitaxel encapsulation. Furthermore, physiochemical characterisation was performed on the optimised Paclitaxel-loaded EL using a variety of methods, including Dynamic Light Scattering, Fourier Transform Infrared Spectroscopy, Atomic force microscopy, elasticity, encapsulation efficiency, and In vitro release. The results reveal the microfluidics' significant impact in enhancing the EL characteristics of EL, especially small and controllable size, Low PDI, and high encapsulation efficiency. Moreover, the edge activator type and concentration highly affect the EL characteristics. The Tween 80 formulations with optimised concentration provide the most suitable size and higher encapsulation efficiency. The release profile of the formulations showed more immediate release from the EL with higher edge activator concentration and a higher % of the released dug from the Tween 80 formulations.

Application of biomacromolecule-based passive penetration enhancement technique in superficial tumor therapy: A review

Transdermal drug delivery (TDD) has shown great promise in superficial tumor therapy due to its noninvasive and avoidance of the first-pass effect. Especially, passive penetration enhancement technique (PPET) provides the technical basis for TDD by temporarily altering the skin surface structure without requiring external energy. Biomacromolecules and their derived nanocarriers offer a wide range of options for PPET development, with outstanding biocompatibility and biodegradability. Furthermore, the abundant functional groups on biomacromolecule surfaces can be modified to yield functional materials capable of targeting specific sites and responding to stimuli. This enables precise drug delivery to the tumor site and controlled drug release, with the potential to replace traditional drug delivery methods and make PPET-related personalized medicine a reality. This review focuses on the mechanism of biomacromolecules and nanocarriers with skin, and the impact of nanocarriers' surface properties of nanocarriers on PPET efficiency. The applications of biomacromolecule-based PPET in superficial tumor therapy are also summarized. In addition, the advantages and limitations are discussed, and their future trends are projected based on the existing work of biomacromolecule-based PPET.

Characterization Methods for Nanoparticle-Skin Interactions: An Overview

Research progresses have led to the development of different kinds of nanoplatforms to deliver drugs through different biological membranes. Particularly, nanocarriers represent a precious means to treat skin pathologies, due to their capability to solubilize lipophilic and hydrophilic drugs, to control their release, and to promote their permeation through the stratum corneum barrier. A crucial point in the development of nano-delivery systems relies on their characterization, as well as in the assessment of their interaction with tissues, in order to predict their fate under in vivo administration. The size of nanoparticles, their shape, and the type of matrix can influence their biodistribution inside the skin strata and their cellular uptake. In this respect, an overview of some characterization methods employed to investigate nanoparticles intended for topical administration is presented here, namely dynamic light scattering, zeta potential, scanning and transmission electron microscopy, X-ray diffraction, atomic force microscopy, Fourier transform infrared and Raman spectroscopy. In addition, the main fluorescence methods employed to detect the in vitro nanoparticles interaction with skin cell lines, such as fluorescence-activated cell sorting or confocal imaging, are described, considering different examples of applications. Finally, recent studies on the techniques employed to determine the nanoparticle presence in the skin by ex vivo and in vivo models are reported.

Carbomer Hydrogels with Microencapsulated α-Tocopherol: Focus on the Biocompatibility of the Microcapsules, Topical Application Attributes, and In Vitro Release Study

The microencapsulation of α-tocopherol based on the complex coacervation of low-molecular-weight chitosan (LMWC) and sodium lauryl ether sulphate (SLES) without harmful crosslinkers can provide biocompatible carriers that protect it from photodegradation and air oxidation. In this study, the influence of the microcapsule wall composition on carrier performance, compatibility with a high-water-content vehicle for topical application, and release of α-tocopherol were investigated. Although the absence of aldehyde crosslinkers decreased the encapsulation efficiency of α-tocopherol (~70%), the variation in the LMWC/SLES mass ratio (2:1 or 1:1) had no significant effect on the moisture content and microcapsule size. The prepared microcapsule-loaded carbomer hydrogels were soft semisolids with pseudoplastic flow behavior. The integrity of microcapsules embedded in the hydrogel was confirmed by light microscopy. The microcapsules reduced the pH, apparent viscosity, and hysteresis area of the hydrogels, while increasing their spreading ability on a flat inert surface and dispersion rate in artificial sweat. The in vitro release of α-tocopherol from crosslinker-free microcapsule-loaded hydrogels was diffusion-controlled. The release profile was influenced by the LMWC/SLES mass ratio, apparent viscosity, type of synthetic membrane, and acceptor medium composition. Better data quality for the model-independent analysis was achieved when a cellulose nitrate membrane and ethyl alcohol 60% w/w as acceptor medium were used.

New graphene-containing pharmaceutical formulations for infrared lamps-based phototherapy of skin cancer: In vitro validation and ex-vivo human skin permeation

Basal cell carcinoma (BCC) is the most common form of human cancer, and treatment usually involves surgery, with alternative strategies being needed. We propose the use of carbopol hydrogels (HG) for topical administration of nanographene oxide (GOn) and partially-reduced nanographene oxide (p-rGOn) for photothermal therapy (PTT) of BCC. GOn and p-rGOn incorporated into the HG present lateral sizes ∼200 nm, being stable for 8 months. After 20 min irradiation with an infrared (IR) photothermal therapy lamp (15.70 mW cm-2), GOn-HG increased temperature to 44.7 °C, while p-rGOn-HG reached 47.0 °C. Human skin fibroblasts (HFF-1) cultured with both hydrogels (250 μg mL-1) maintained their morphology and viability. After 20 min IR irradiation, p-rGOn HG (250 μg mL-1) completely eradicated skin cancer cells (A-431). Ex vivo human skin permeability tests showed that the materials can successfully achieve therapeutic concentrations (250 μg mL-1) inside the skin, in 2.0 h for GO HG or 0.5 h for p-rGOn HG.

High mobility group box 1 cytokine targeted topical delivery of resveratrol embedded nanoemulgel for the management of atopic dermatitis

Resveratrol is a polyphenolic compound showing anti-inflammatory activity by inhibition of high mobility group box 1 cytokine responsible for the activation of nuclear factor-κB pathway in atopic dermatitis. To evaluate the efficacy of resveratrol through topical route we have developed resveratrol-loaded nanoemulgel for the effective management of atopic dermatitis in mice model. The resveratrol-loaded nanoemulsion (0.5%, 0.75% and 1% w/w) was optimized by spontaneous nano-emulsification. The optimized resveratrol-loaded nanoemulsions showed average globule size in the 180-230 nm range and found to be monodispersed. The resveratrol nanoemulgel was prepared with a SEPINEO™ P 600 gel base and propylene glycol. Ex vivo permeation and retention study resulted in significantly higher skin retention of resveratrol from resveratrol-loaded nanoemulgel than free resveratrol-loaded gel. Preclinical efficacy of resveratrol nanoemulgel displayed promising therapeutic outcomes where, western blotting of skin tissues disclosed a significant reduction in the relative expression of high mobility group box 1, the receptor for advanced glycation end products, toll-like receptor-4 and phosphorylated nuclear factor-κB. Further, real-time polymerase chain reaction also disclosed a significant reduction in pro-inflammatory cytokines such as thymic stromal lymphopoietin, interleukin-4, interleukin-13, interleukin-31, tumor necrosis factor-α and interleukin-6. The histopathological examination of skin sections showed improvement in the skin condition. Collectively, the findings from our study showcased the significant improvement in the atopic dermatitis skin condition in mice model after topical application of resveratrol loaded nanoemulgel.

Carbopol 940-based hydrogels loading synergistic combination of quercetin and luteolin from the herb Euphorbia humifusa to promote Staphylococcus aureus infected wound healing

With the increasing prevalence of Staphylococcus aureus infections, rapid emergence of drug resistance and the slow healing of infected wounds, developing an efficient antibiotic-free multifunctional wound dressing for inhibiting S. aureus and simultaneously facilitating wound healing have become a huge challenge. Due to their excellent biocompatibility and biodegradability, some carbopol hydrogels based on plant extracts or purified compounds have already been applied in wound healing treatment. In China, Euphorbia humifusa Willd. (EuH) has been traditionally used as a medicine and food homologous medicine for the treatment of furuncles and carbuncles mainly caused by S. aureus infection. In an earlier study, EuH-originated flavonoids quercetin (QU) and luteolin (LU) could serve as a potential source for anti-S. aureus drug discovery when used in synergy. However, the in vivo effects of QU and LU on S. aureus-infected wound healing are still unknown. In this study, we found a series of Carbopol 940-based hydrogels loading QU and LU in combination could disinfect S. aureus and also could promote wound healing. In the full-thickness skin defect mouse model infected with S. aureus, the wound contraction ratio, bacterial burden, skin hyperplasia and inflammation score, as well as collagen deposition and blood vessels were then investigated. The results indicate that the optimized QL2 [QU (32 μg mL-1)-LU (8 μg mL-1)] hydrogel with biocompatibility significantly promoted S. aureus-infected wound healing through anti-infection, anti-inflammation, collagen deposition, and angiogenesis, revealing it as a promising alternative for infected wound repair.

Intratumoral Treatment of Melanoma Tumors with Large Surface Area Microparticle Paclitaxel and Synergy with Immune Checkpoint Inhibition

The effects of intratumoral (IT) large surface area microparticle paclitaxel (LSAM-PTX) alone and in combination with systemic administration of the programmed cell death protein antibody (anti-mPD-1) were evaluated in a syngeneic murine model of melanoma. Groups of mice with subcutaneously implanted Clone M3 (Cloudman S91) tumors were treated with single and combination therapies. Tumor volume (TV) measurements, body weights, and clinical observations were followed in-life. At end of study, tumor-site tissues were collected, measured, and processed for flow cytometry along with blood and lymph nodes. The combination of LSAM-PTX + anti-mPD-1 resulted in an antitumoral response, which produced a significant decrease in TV compared to control animals. TV decreases also occurred in the LSAM-PTX and anti-mPD-1 groups. Flow cytometry analysis found increases in granulocytes and M2 macrophages and decreases in dendritic cells (DC) and monocytic myeloid-derived suppressor cells (M-MDSC) in tumor-site tissues. Increases in granulocytes and decreases in CD4+ T cells, macrophages, and M1 macrophages were found in the blood of animals administered the combination treatment. Increases in natural killer (NK) cells were found in lymph node tissue in the combination treatment group. These findings suggest that IT LSAM-PTX may provide benefit in the local treatment of melanomas and may synergize with systemic anti-PD-1 therapy, leading to additional tumoricidal outcomes without added systemic toxicity.

Skin cancer: understanding the journey of transformation from conventional to advanced treatment approaches

Skin cancer is a global threat to the healthcare system and is estimated to incline tremendously in the next 20 years, if not diagnosed at an early stage. Even though it is curable at an early stage, novel drug identification, clinical success, and drug resistance is another major challenge. To bridge the gap and bring effective treatment, it is important to understand the etiology of skin carcinoma, the mechanism of cell proliferation, factors affecting cell growth, and the mechanism of drug resistance. The current article focusses on understanding the structural diversity of skin cancers, treatments available till date including phytocompounds, chemotherapy, radiotherapy, photothermal therapy, surgery, combination therapy, molecular targets associated with cancer growth and metastasis, and special emphasis on nanotechnology-based approaches for downregulating the deleterious disease. A detailed analysis with respect to types of nanoparticles and their scope in overcoming multidrug resistance as well as associated clinical trials has been discussed.

Karaya/Gellan-Gum-Based Bilayer Films Containing 3,3'-Diindolylmethane-Loaded Nanocapsules: A Promising Alternative to Melanoma Topical Treatment

This study aimed to incorporate nanocapsules containing 3,3'-diindolylmethane (DIM) with antitumor activity into a bilayer film of karaya and gellan gums for use in topical melanoma therapy. Nanocarriers and films were prepared by interfacial deposition of the preformed polymer and solvent casting methods, respectively. Incorporating DIM into nanocapsules increased its antitumor potential against human melanoma cells (A-375) (IC50 > 24.00 µg/mL free DIM × 2.89 µg/mL nanocapsules). The films were transparent, hydrophilic (θ < 90°), had homogeneous thickness and weight, and had a DIM content of 106 µg/cm2. Radical ABTS+ scavenger assay showed that the DIM films presented promising antioxidant action. Remarkably, the films showed selective bioadhesive potential on the karaya gum side. Considering the mechanical analyses, the nanotechnology-based films presented appropriate behavior for cutaneous application and controlled DIM release profile, which could increase the residence time on the application site. Furthermore, the nanofilms were found to increase the permeation of DIM into the epidermis, where melanoma develops. Lastly, the films were non-hemolytic (hemolysis test) and non-irritant (HET-CAM assay). In summary, the combination of karaya and gellan gum in bilayer films that contain nanoencapsulated DIM has demonstrated potential in the topical treatment of melanoma and could serve as a viable option for administering DIM for cutaneous melanoma therapy.

Nanodelivery systems for cutaneous melanoma treatment

Cutaneous melanoma (CM) is a multifactorial disease whose treatment still presents challenges: the rapid progression to advanced CM, which leads to frequent recurrences even after surgical excision and, notably, the low response rates and resistance to the available therapies, particularly in the case of unresectable metastatic CM. Thereby, alternative innovative therapeutic approaches for CM continue to be searched. In this review we discuss relevant preclinical research studies, and provide a broad-brush analysis of patents and clinical trials which involve the application of nanotechnology-based delivery systems in CM therapy. Nanodelivery systems have been developed for the delivery of anticancer biomolecules to CM, which can be administered by different routes. Overall, nanosystems could promote technological advances in several therapeutic modalities and can be used in combinatorial therapies. Nevertheless, the results of these preclinical studies have not been translated to clinical applications. Thus, concerted and collaborative research studies involving basic, applied, translational, and clinical scientists need to be performed to allow the development of effective and safe nanomedicines to treat CM.

Exploration of hemocompatibility and intratumoral accumulation of paclitaxel after loco-regional administration of thermoresponsive hydrogel composed of poloxamer and xanthan gum: An application to dose-dense chemotherapy

Although paclitaxel is a front-line chemotherapeutic agent for the treatment of metastatic breast cancer, its intravenous therapy produces deleterious adverse effects. In an attempt to address the issue, the present study aimed to develop a paclitaxel loaded thermosensitive/thermoresponsive hydrogel (PTXNp-TGel) for loco-regional administration to breast tumors to provide dose-dense chemotherapy. Poloxamer and xanthan gum were used to prepare TGel by the cold method. In vitro and in vivo performance of PTXNp-TGel was compared with TGel, pure drug loaded TGel (PTX-TGel) and marketed formulation, Taxol®. The formulated PTXNp-TGel showed acceptable gelation temperature and time (37 °C and 57 s), lower viscosity at room temperature and higher viscosity at body temperature to support sol-gel transition with increasing temperature, and sustained drug release up to 21 days. Additionally, PTXNp-TGel showed negligible hemolytic toxicity as compared to PTX-TGel and Taxol®. Intratumoral administration of PTXNp-TGel produced significantly higher antitumor activity as indicated by lowest relative tumor volume (1.50) and relative antitumor proliferation rate (27.71 %) in comparison with PTX-TGel, Taxol®, and PTXNp (p < 0.05). Finally, insignificant body weight loss during the experimental period, lack of hematotoxicity, nephrotoxicity, and hepatotoxicity imply improved therapeutic performance of the locally administrated dose-dense therapy of PTXNp-TGel as compared to Taxol®.

Advancements in nanoparticle-based treatment approaches for skin cancer therapy

Skin cancer has emerged as the fifth most commonly reported cancer in the world, causing a burden on global health and the economy. The enormously rising environmental changes, industrialization, and genetic modification have further exacerbated skin cancer statistics. Current treatment modalities such as surgery, radiotherapy, conventional chemotherapy, targeted therapy, and immunotherapy are facing several issues related to cost, toxicity, and bioavailability thereby leading to declined anti-skin cancer therapeutic efficacy and poor patient compliance. In the context of overcoming this limitation, several nanotechnological advancements have been witnessed so far. Among various nanomaterials, nanoparticles have endowed exorbitant advantages by acting as both therapeutic agents and drug carriers for the remarkable treatment of skin cancer. The small size and large surface area to volume ratio of nanoparticles escalate the skin tumor uptake through their leaky vasculature resulting in enhanced therapeutic efficacy. In this context, the present review provides up to date information about different types and pathology of skin cancer, followed by their current treatment modalities and associated drawbacks. Furthermore, it meticulously discusses the role of numerous inorganic, polymer, and lipid-based nanoparticles in skin cancer therapy with subsequent descriptions of their patents and clinical trials.

Mucoadhesive Polymers and Their Applications in Drug Delivery Systems for the Treatment of Bladder Cancer

Bladder cancer (BC) is the tenth most common type of cancer worldwide, affecting up to four times more men than women. Depending on the stage of the tumor, different therapy protocols are applied. Non-muscle-invasive cancer englobes around 70% of the cases and is usually treated using the transurethral resection of bladder tumor (TURBIT) followed by the instillation of chemotherapy or immunotherapy. However, due to bladder anatomy and physiology, current intravesical therapies present limitations concerning permeation and time of residence. Furthermore, they require several frequent catheter insertions with a reduced interval between doses, which is highly demotivating for the patient. This scenario has encouraged several pieces of research focusing on the development of drug delivery systems (DDS) to improve drug time residence, permeation capacity, and target release. In this review, the current situation of BC is described concerning the disease and available treatments, followed by a report on the main DDS developed in the past few years, focusing on those based on mucoadhesive polymers as a strategy. A brief review of methods to evaluate mucoadhesion properties is also presented; lastly, different polymers suitable for this application are discussed.

Micelles in Cancer Therapy: An Update on Preclinical and Clinical Status

BACKGROUND

In the recent years, Micelles represent a promising carrier for the treatment and diagnosis of cancer. Architecturally, micelles are self-assembled nanosized colloidal aggregates prepared from amphiphilic surfactant with a hydrophobic core and hydrophilic shell. Such a composition makes them a potential carrier for delivery of hydrophobic anticancer drugs with in their core.

METHODS

Micelles have received increasing interest as an enhanced permeability and retention (EPR) targeted drug delivery systems for cancer treatment. Micelles can be modified to contribute various attractive properties, for instance, active targeting, stimuli-responsiveness. They have also proven their ability in drug targeting to tumor tissue, enhanced drug accumulation, drug stabilization, tissue penetration, prolong circulation, in vivo biocompatibility, biodegradability and reduced side effects. Micelles have displayed a vital role in multidrug delivery for cancer therapy.

RESULTS AND DISCUSSION

The aim of the present review is to provide an overview on the status of micellar nanoformulations for anticancer agents, including their pre-clinical and clinical researches. Emphasis is placed on presenting the newer strategies to enhance the therapeutic efficacy of anticancer drug at the target site. The type of co-polymers used and methods for the preparation of micelles are also highlighted in the paper.

Carbopol 940 hydrogel containing curcumin-loaded micelles for skin delivery and application in inflammation treatment and wound healing

Inflammation and excessive reactive oxygen species production are main reason for slow wound healing, which needs an efficient therapy in clinic. In the paper, curcumin-enveloped methoxy poly(ethylene glycol)-poly(-valerolactone)-poly(-caprolactone) (MPEG-PVL-PCL) micelles...

Hydrogels for modified-release drug delivery systems

Hydrogels for the modified-release drug delivery systems is a continuously growing area of interest for the pharmaceutical industry. According to the global market, the use of polymers in this area is projected to reach $31.4 million by 2027. This review discusses the recent advances and perspectives of hydrogel in drug delivery systems for oral, parenteral, nasal, topical, and ophthalmic. The search strategy did in January 2021, and it conducted an extensive database to identify studies published from January 2010 to December 2020.We described the main characteristic of the polymers to obtain an ideal hydrogel for a specific route of administration and the formulations that was a highlight in the literature. It concluded that the hydrogels are a set useful to decrease the number of doses, side effects, promote adhesion of patient and enhances the bioavailability of the drugs improving the safety and efficacy of the treatment.

RETRACTED: Transdermal delivery of flurbiprofen from polyoxypropylene-polyoxyethylene block copolymer stabilized reduced graphene oxide to manage pain in spondylitis: In vitro and in vivo studies

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. Significant similarities were noticed post-publication between this article and the article that was previously published by an apparently unrelated group of authors: Weifan Li, Guangqi Zhang and Xiaoxia Wei, Journal of Biomaterials Applications 35 (2021) 1034 https://doi.org/10.1177/0885328220988462. Moreover, the authors did not respond to the journal request to comment on these similarities and to provide the raw data, and the Editor-in-Chief decided to retract the article. One of the conditions of submission of a paper for publication is that authors declare explicitly that the paper has not been previously published and is not under consideration for publication elsewhere. As such this article represents an abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.

Improvement of Imiquimod Solubilization and Skin Retention via TPGS Micelles: Exploiting the Co-Solubilizing Effect of Oleic Acid

Imiquimod (IMQ) is an immunostimulant drug approved for the topical treatment of actinic keratosis, external genital-perianal warts as well as superficial basal cell carcinoma that is used off-label for the treatment of different forms of skin cancers, including some malignant melanocytic proliferations such as lentigo maligna, atypical nevi and other in situ melanoma-related diseases. Imiquimod skin delivery has proven to be a real challenge due to its very low water-solubility and reduced skin penetration capacity. The aim of the work was to improve the drug solubility and skin retention using micelles of d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS), a water-soluble derivative of vitamin E, co-encapsulating various lipophilic compounds with the potential ability to improve imiquimod affinity for the micellar core, and thus its loading into the nanocarrier. The formulations were characterized in terms of particle size, zeta potential and stability over time and micelles performance on the skin was evaluated through the quantification of imiquimod retention in the skin layers and the visualization of a micelle-loaded fluorescent dye by two-photon microscopy. The results showed that imiquimod solubility strictly depends on the nature and concentration of the co-encapsulated compounds. The micellar formulation based on TPGS and oleic acid was identified as the most interesting in terms of both drug solubility (which was increased from few µg/mL to 1154.01 ± 112.78 µg/mL) and micellar stability (which was evaluated up to 6 months from micelles preparation). The delivery efficiency after the application of this formulation alone or incorporated in hydrogels showed to be 42- and 25-folds higher than the one of the commercial creams.

Cloves (Syzygium aromaticum) fluid gel on healing of pododermatitis in rabbits

Wounds are damaging to quality life of confined animals, causing dysfunction in spinal, members injuries, and reduction in productive performance. This research investigated the clove antimicrobial and antioxidant activity on the healing of decubitus wounds (pododermatitis) of rabbits (Oryctolagus cuniculus). Adult animals were treated for 21 days every three days with a fluid gel spray in the wound region: control fluid gel without addition of clove (FGC0), fluid gel with addition of 1% clove powder (FGC1), and fluid gel with 2% clove powder (FGC2). Microbiological analysis for Escherichia coli and Pseudomonas spp. were performed during 21 days of experimental period. After this period, samples from treated skin were evaluated for histological analysis and evaluation of the healing process by spectroscopy (FTIR-ATR). Rabbits treated with FGC2 showed advanced healing and decreased tissue inflammation similar to healthy rabbits, while FGC0 rabbits showed a decrease in bacterial contamination without signs of healing. Both FGC1 and FGC2 rabbits demonstrated antimicrobial and antioxidant action against both bacteria tested, favoring the wound healing process. Considering the results, the use of fluid gel with 2% of clove powder (Syzigium aromaticum) based on the best antimicrobial, antioxidant and anti-inflammatory activities on healing of decubitus wounds (pododermatitis) of rabbits in commercial farming system.

Design, optimization and evaluation of a microemulsion-based hydrogel with high malleability for enhanced transdermal delivery of levamisole

The objective of the present study was to prepare and evaluate a microemulsion-based hydrogel with high malleability as a transdermal delivery carrier for levamisole (LMS). A pseudo-ternary phase diagram and D-optimal mixture design were utilized to screen and optimize the microemulsion, and the formulation comprised 7.5% Maisine^TM35-1, 33% S_mix and 59.5% water. The microemulsion was physically stable with an average size of 19.3 ± 0.1 nm and zeta potential of -3.84 ± 0.05 mV. Moreover, a highly malleable alginate-boronic acid (alginate-BA) gel was prepared and could come into close contact with highly curved skin. The optimized microemulsion was loaded into alginate-BA gel and subjected to ex vivo and in vivo investigation. The microemulsion-based gel had desirable characterization, good stability and negligible skin irritation. The results of ex vivo permeation study showed that LMS achieved a significantly higher cumulative amount from the LMS-loaded microemulsion-based gel than that from the LMS-gel. The pharmacokinetic study showed a twofold increase in relative bioavailability compared to the commercial liniment. These results provide insight into the capability of the developed malleable microemulsion-based gel to enhance the transdermal permeation and bioavailability of LMS.

Triptolide laden reduced graphene oxide transdermal hydrogel to manage knee arthritis: in vitro and in vivo studies

Triptolide (extract of herb Tripterygium wilfordii) is widely used in rheumatoid arthritis due to its potent immunosuppressant effect. The marketed oral (tablet dosage forms) and parenteral injections have short duration of action (half-life = 38 min) and not limited to multiorgan toxicity, which restrict the use of triptolide in clinical practice. In this study, a triptolide-loaded Pluronic® F68-reduced graphene oxide transdermal (non-invasive) hydrogel was developed to achieve sustained release of triptolide. Fourier transform infrared spectroscopy, X-ray diffraction, and Raman spectroscopy confirmed the synthesis of Pluronic^® F68-reduced graphene oxide. Transmission electron microscopy showed flat wrinkled-nanosheets. The developed hydrogel showed desirable viscosity (11,261-11,365 cps), adhesiveness (0.25 mJ), hardness (6.5 g), and cohesiveness (1.85) for transdermal application. The ex vivo release study demonstrated the ability of the Pluronic^® F68-reduced graphene oxide hydrogel to prolong release up to 14 h (63.64-96.78%), owing to the strong π-π interactions between the graphene oxide and the triptolide. The in vivo pharmacokinetic parameters in the rat model confirmed the improvement in the relative bioavailability (3.3-fold) with Pluronic^® F68-reduced graphene oxide hydrogel in comparison to the control hydrogel without reduced graphene oxide. The anti-rheumatoid efficacy model suggest the potential application of Pluronic^® F68-reduced graphene oxide hydrogel to treat knee rheumatoid arthritis (70-75% resolution) to substitute tablets and parenteral injections.

Rheological behavior study and its significance in the assessment of application properties and physical stability of phytosome loaded hydrogels

Phytosomes are amphiphilic molecular complexes of substances of plant origin and phospholipids that are considered as active ingredients of dermopharmaceutical and cosmetic formulations of potentially improved efficiency. The study aim was the formulation of carbomer hydrogels with commercially available phytosomes of escin (Escin ß-Sitosterol Phytosome®) (EP) and 18-ß glycyrrhetinic acid (18-ß Glycyrrhetinic Acid Phytosome®) (GP) and evaluation of their application properties and real-time physical stability. Phytosomes incorporation did not significantly affect pH of the hydrogels, which was acceptable for cutaneous application. However, these hydrogels had significantly different organoleptic properties (opaque and softer consistency) compared to the hydrogel without active substance (C) and the hydrogels with pure active substances (E and G) used for comparison. The values of maximum and minimum apparent viscosity and yield stress were significantly lower in phytosome-loaded hydrogels. The results of oscillatory rheological analysis indicated that viscous character prevails in EP and GP hydrogels (elastic modulus (G')˂viscous modulus (G")), while in hydrogels C, E and G elastic properties were more pronounced (G'˃G"). Escin phytosome had greater influence on carbomer gel network strength. Phytosome-loaded hydrogels were physically stable during 24 months of storage under ambient conditions, although the rheological analysis also indicated a potential risk of sedimentation.