Development and evaluation of silver sulfadiazine loaded microsponge based gel for partial thickness (second degree) burn wounds

Advancing burn wound treatment: exploring hydrogel as a transdermal drug delivery system

Burn injuries are prevalent and life-threatening forms that contribute significantly to mortality rates due to associated wound infections. The management of burn wounds presents substantial challenges. Hydrogel exhibits tremendous potential as an ideal alternative to traditional wound dressings such as gauze. This is primarily attributed to its three-dimensional (3D) crosslinked polymer network, which possesses a high water content, fostering a moist environment that supports effective burn wound healing. Additionally, hydrogel facilitates the penetration of loaded therapeutic agents throughout the wound surface, combating burn wound pathogens through the hydration effect and thereby enhancing the healing process. However, the presence of eschar formation on burn wounds obstructs the passive diffusion of therapeutics, impairing the efficacy of hydrogel as a wound dressing, particularly in cases of severe burns involving deeper tissue damage. This review focuses on exploring the potential of hydrogel as a carrier for transdermal drug delivery in burn wound treatment. Furthermore, strategies aimed at enhancing the transdermal delivery of therapeutic agents from hydrogel to optimize burn wound healing are also discussed.

Preparation of Microsponge Drug Delivery System (MSDDS) Followed by a Scale-Up Approach

In 1987, Won invented the solid-phase porous microsphere (MS), which stores bioactive compounds in many interconnected voids. Spherical particles (5-300 μm), MS, may form clusters of smaller spheres, resulting in many benefits. The current investigation focussed on gel-encased formulation, which can be suitable for dermal usage. First, quasi-emulsion (w/o/w) solvent evaporation was used to prepare 5-fluorouracil (5 FU) MS particles. The final product was characterized (SEM shows porous structure, FTIR and DSC showed drug compatibility with excipients, and gel formulation is shear-thinning) and further scaled up using the 8-fold method. Furthermore, CCD (Central Composite Design) was implemented to obtain the optimized results. After optimizing the conditions, including the polymer (600 mg, ethyl cellulose (EC), eudragit RS 100 (ERS)), stirring speed (1197 rpm), and surfactant concentration (2% w/v), we achieved the following results: optimal yield (63%), mean particle size (152 µm), drug entrapment efficiency (76%), and cumulative drug release (74.24% within 8 h). These findings are promising for industrial applications and align with the objectives outlined in UN Sustainable Development Goals 3, 9, and 17, as well as the goals of the G20 initiative.

Microsponges-mediated targeted topical delivery of rosemary oil for hair growth promotion: optimization and in-vivo studies

Individuals experiencing hair loss, irrespective of gender, confront significant psychological challenges. This study explores the untapped potential of rosemary oil (ROS) to stimulate hair growth, addressing its limited permeability. The focus is on innovating ROS-loaded microsponges (MS) for enhanced topical application. Utilizing Box-Behnken design (33), the study optimizes ROS-MS compositions by varying solvent volume, polymer mix, and drug concentration. The optimized ROS-MS formulation exhibits noteworthy attributes: a 94% ± 0.04 production yield, 99.6% ± 0.5 encapsulation efficiency, and 96.4% ± 1.6 cumulative ROS release within 24 h. These microsponges exhibit uniformity with a particle size of 14.1 µm ± 4.5. The OPT-ROSMS-gel showcases favorable characteristics in appearance, spreadability, pH, drug content, and extrudability. Ex-vivo skin deposition tests highlight heightened permeability of OPT-ROSMS-gel compared to pure ROS-gel, resulting in three-fold increased follicular retention. In-vivo studies underscore the superior efficacy of OPT-ROSMS-gel, revealing enhanced hair development in length, thickness, and bulb diameter, surpassing ROS-gel and minoxidil by approximately 1.2 and 1.5 times, respectively, along with nearly two-fold increase in β-catenin levels. In conclusion, microsponges emerge as a promising ROS delivery method, effectively addressing hair loss. This research advances hair loss treatments and underscores the significance of this innovative paradigm in fostering hair growth.

Development of 4-phenylbutyric acid microsponge gel formulations for the treatment of lewisite-mediated skin injury

Lewisite, a chemical warfare agent, causes skin blisters, erythema, edema, and inflammation, requiring mitigation strategies in case of accidental or deliberate exposure. 4-phenyl butyric acid (4-PBA), a chemical chaperone, reduces endoplasmic reticulum stress and skin inflammation. The study aimed to encapsulate 4-PBA in microsponges for effective, sustained delivery against lewisite injury. Porous microsponges in a topical gel would potentially sustain delivery and improve residence time on the skin. Microsponges were developed using the quasi-emulsion solvent diffusion method with Eudragit RS100. Optimized formulation showed 10.58%w/w drug loading was incorporated in a carboxymethylcellulose (CMC) and Carbopol gel for in vitro release and permeation testing using dermatomed human skin. A sustained release was obtained from all vehicles in the release study, and IVPT results showed that compared to the control (41.52 ± 2.54 µg/sq.cm), a sustained permeation profile with a reduced delivery was observed for microsponges in PBS (14.16 ± 1.23 µg/sq.cm) along with Carbopol 980 gel (12.55 ± 1.41 µg/sq.cm), and CMC gel (10.09 ± 1.23 µg/sq.cm) at 24 h. Optimized formulation showed significant protection against lewisite surrogate phenyl arsine oxide (PAO) challenged skin injury in Ptch1+/-/SKH-1 hairless mice at gross and molecular levels. A reduction in Draize score by 29%, a reduction in skin bifold thickness by 8%, a significant reduction in levels of IL-1β, IL6, and GM-CSF by 54%, 30%, and 55%, respectively, and a reduction in apoptosis by 31% was observed. Thus, the translational feasibility of 4-PBA microsponges for effective, sustained delivery against lewisite skin injury is demonstrated.

Obliteration of H. pylori infection through the development of a novel thyme oil laden nanoporous gastric floating microsponge

Thyme oil (TO) is a valuable essential oil believed to possess a variety of bioactivities, including antibacterial, anticancer, and antioxidant properties. These attributes grant TO the excellent capability to treat a wide range of diseases, particularly the effective eradication of Helicobacter pylori infection in the stomach. However, its practical use is limited by its low stability under atmospheric conditions. Our current research aims to encapsulate TO in eudragit (EGT) microsponges to enhance its stability and improve its effectiveness against H. pylori. The TO microsponges were prepared using EGT as a polymer, polysorbate 80 as a stabilizer, and dichloromethane (DCM) as a solvent via the quasi-emulsion solvent evaporation method. The product yield, particle size, surface morphology, entrapment efficiency, drug-polymer interaction, in-vitro floating, and in-vitro drug release of the microsponges were evaluated. The most promising microsponge was tested against H. pylori ATCC 43504 strains. The results showed that the microsponges exhibited a high product yield (ranging from 41 % ± 0.75-81.27 % ± 1.13), excellent entrapment efficiency (ranging from 63.01 % ± 0.79-88.64 % ± 0.98), prolonged in-vitro floating time (more than 12 h) and sustained in-vitro drug release for 18 h (81.53 %). Scanning electron microscopy results indicated that the microsponges were spherical in shape with a spongy surface. The average particle size of the selected microsponges was determined to be 49.79 ± 1.4 μm, and their average pore size was measured to be 0.81 ± 0.14 μm. DSC study results revealed that TO was physically entrapped in the microsponges. In-vitro anti-H. pylori activity studies demonstrated that TO in microsponge was more effective against H. pylori than pure TO. In conclusion, the developed microsponges containing thyme oil provide a promising alternative for the efficient targeting and eradication of H. Pylori infection.

Emulgel based on fish skin collagen-microalgae-silver increased neovascularization and re-epithelialization of full thickness burn in rats

Deep skin burn represents a global morbidity and mortality problem, and the limitation of topical treatment agents has motivated research to development new formulations capable of preventing infections and accelerating healing. The aim of this work was to develop and characterize an emulgel based on collagen (COL) and gelatin (GEL) extracted from fish skin associated with Chlorella vulgaris extract (CE) and silver nitrate (AgNO3). COL and GEL were characterized by physicochemical and thermal analyses; and CE by electrophoresis and its antioxidant capacity. Three emulgels formulations were developed: COL (0.5%) + GEL (2.5%) (E1), COL+GEL+CE (1%) (E2), and COL+GEL+CE + AgNO3 (0.1%) (E3). All formulations were characterized by physicochemical, rheology assays, and preclinical analyses: cytotoxicity (in vitro) and healing potential using a burn model in rats. COL and GEL showed typical physicochemical characteristics, and CE presented 1.3 mg/mL of proteins and antioxidant activity of 76%. Emulgels presented a coherent physicochemical profile and pseudoplastic behavior. Preclinical analysis showed concentration-dependent cytotoxicity against fibroblast and keratinocytes. In addition, all emulgels induced similar percentages of wound contraction and complete wound closure in 28 days. The histopathological analysis showed higher scores for polymorphonuclear cells to E1 and greater neovascularization and re-epithelialization to E3. Then, E3 formulation has potential to improve burn healing, although its use in a clinical setting requires further studies.

Cutaneous Pharmacokinetics of Topically Applied Novel Dermatological Formulations

Novel formulations are developed for dermatological applications to address a wide range of patient needs and therapeutic challenges. By pushing the limits of pharmaceutical technology, these formulations strive to provide safer, more effective, and patient-friendly solutions for dermatological concerns, ultimately improving the overall quality of dermatological care. The article explores the different types of novel dermatological formulations, including nanocarriers, transdermal patches, microsponges, and microneedles, and the techniques involved in the cutaneous pharmacokinetics of these innovative formulations. Furthermore, the significance of knowing cutaneous pharmacokinetics and the difficulties faced during pharmacokinetic assessment have been emphasized. The article examines all the methods employed for the pharmacokinetic evaluation of novel dermatological formulations. In addition to a concise overview of earlier techniques, discussions on novel methodologies, including tape stripping, in vitro permeation testing, cutaneous microdialysis, confocal Raman microscopy, and matrix-assisted laser desorption/ionization mass spectrometry have been conducted. Emerging technologies like the use of microfluidic devices for skin absorption studies and computational models for predicting drug pharmacokinetics have also been discussed. This article serves as a valuable resource for researchers, scientists, and pharmaceutical professionals determined to enhance the development and understanding of novel dermatological drug products and the complex dynamics of cutaneous pharmacokinetics.

Enhancing Wound Healing: A Novel Topical Emulsion Combining CW49 Peptide and Lavender Essential Oil for Accelerated Regeneration and Antibacterial Protection

Wound healing is a complex process involving blood cells, extracellular matrix, and parenchymal cells. Research on biomimetics in amphibian skin has identified the CW49 peptide from Odorrana grahami, which has been demonstrated to promote wound regeneration. Additionally, lavender essential oil exhibits anti-inflammatory and antibacterial activities. Given these considerations, we propose an innovative emulsion that combines the CW49 peptide with lavender oil. This novel formulation could serve as a potent topical treatment, potentially fostering the regeneration of damaged tissues and providing robust antibacterial protection for skin wounds. This study investigates the physicochemical properties, biocompatibility, and in vitro regenerative capacity of the active components and the emulsion. The results show that the emulsion possesses appropriate rheological characteristics for topical application. Both the CW49 peptide and lavender oil exhibit high viability in human keratinocytes, indicating their biocompatibility. The emulsion induces hemolysis and platelet aggregation, an expected behavior for such topical treatments. Furthermore, the lavender-oil emulsion demonstrates antibacterial activity against both Gram-positive and Gram-negative bacterial strains. Finally, the regenerative potential of the emulsion and its active components is confirmed in a 2D wound model using human keratinocytes. In conclusion, the formulated emulsion, which combines the CW49 peptide and lavender oil, shows great promise as a topical treatment for wound healing. Further research is needed to validate these findings in more advanced in vitro models and in vivo settings, potentially leading to improved wound-care management and novel therapeutic options for patients with skin injuries.

A Brief Introduction to Chemical Reaction Optimization

From the start of a synthetic chemist's training, experiments are conducted based on recipes from textbooks and manuscripts that achieve clean reaction outcomes, allowing the scientist to develop practical skills and some chemical intuition. This procedure is often kept long into a researcher's career, as new recipes are developed based on similar reaction protocols, and intuition-guided deviations are conducted through learning from failed experiments. However, when attempting to understand chemical systems of interest, it has been shown that model-based, algorithm-based, and miniaturized high-throughput techniques outperform human chemical intuition and achieve reaction optimization in a much more time- and material-efficient manner; this is covered in detail in this paper. As many synthetic chemists are not exposed to these techniques in undergraduate teaching, this leads to a disproportionate number of scientists that wish to optimize their reactions but are unable to use these methodologies or are simply unaware of their existence. This review highlights the basics, and the cutting-edge, of modern chemical reaction optimization as well as its relation to process scale-up and can thereby serve as a reference for inspired scientists for each of these techniques, detailing several of their respective applications.

Development and Characterization of Polymeric Microsponge as a New Vehicle to Deliver Urea Topically

BACKGROUND

Topical delivery of therapeutic agents is considered beneficial due to various advantages like ease of administration, avoidance of the first-pass effect, and improved patient compliance. Therefore, scientists around the globe are exploring this route for the delivery of drugs nowadays.

OBJECTIVE

The present patent investigation aimed to prepare, optimize, and characterize the urealoaded microsponges for efficient topical delivery in vitro.

METHODS

Urea-loaded ethylcellulose microsponges were prepared using quasi emulsion solvent diffusion technique and optimized using Box-Behnken design (BBD). Furthermore, they were characterized in-vitro using various techniques like scanning electron microscopy (SEM), differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FT-IR), and X-ray diffraction analysis (XRD). In-vitro drug release and release kinetics analysis was also performed.

RESULTS

Urea-loaded microsponges were spherical and porous. Optimized urea loaded microsponges showed a minimum size (39.78 ± 1.98 μm), high entrapment (74.56 ± 2.8%), acceptable polydispersity index (PDI) (0.224 ± 0.081) and zeta potential (-21.9 ± 2.9 mV). These microsponges were capable of sustaining the release of urea for 24 h (91.21 ± 5.20%), and the mechanism of release was the combination of diffusion and erosion.

CONCLUSION

The developed microsponge system could be beneficial for topical delivery of urea as it could reduce the dosing frequency of urea and increase patient compliance through its sustained release.

Quality by Design Guided Development of Polymeric Nanospheres of Terbinafine Hydrochloride for Topical Treatment of Onychomycosis Using a Nano-Gel Formulation

Superficial fungal diseases of the skin and nails are an increasingly common occurrence globally, requiring effective topical treatment to avoid systemic adverse effects. Polymeric nanoparticles have demonstrated sustained and effective drug delivery in a variety of topical formulations. The aim of this project was to develop polymeric antifungal nanospheres containing terbinafine hydrochloride (TBH) to be loaded into a hydrogel formulation for topical nail drug delivery. A quality by design (QbD) approach was used to achieve optimized particles with the desired quality target product profile (QTPP). Polyvinyl alcohol (PVA) at 2% w/v and a drug to polymer ratio of 1:4, together with a robust set of processes and material attributes, resulted in nanoparticles of 108.7 nm with a polydispersity index (PDI) of 0.63, 57.43% recovery, and other desirable characteristics such as zeta potential (ZP), particle shape, aggregation, etc. The nanospheres were incorporated into a carbomer-based gel, and the delivery of TBH through this formulation was evaluated by means of in vitro drug release testing (IVRT) and ex vivo nail permeation study. The gel containing the TBH nanospheres demonstrated a slower and controlled drug release profile compared with the control gel, in addition to a more efficient delivery into the nail. These antifungal nanospheres can be utilized for topical therapy of a multitude of superficial fungal infections.

Application of Metal–Organic Framework in Diagnosis and Treatment of Diabetes

Diabetes-related chronic wounds are often accompanied by a poor wound-healing environment such as high glucose, recurrent infections, and inflammation, and standard wound treatments are fairly limited in their ability to heal these wounds. Metal–organic frameworks (MOFs) have been developed to improve therapeutic outcomes due to their ease of engineering, surface functionalization, and therapeutic properties. In this review, we summarize the different synthesis methods of MOFs and conduct a comprehensive review of the latest research progress of MOFs in the treatment of diabetes and its wounds. State-of-the-art in vivo oral hypoglycemic strategies and the in vitro diagnosis of diabetes are enumerated and different antimicrobial strategies (including physical contact, oxidative stress, photothermal, and related ions or ligands) and provascular strategies for the treatment of diabetic wounds are compared. It focuses on the connections and differences between different applications of MOFs as well as possible directions for improvement. Finally, the potential toxicity of MOFs is also an issue that we cannot ignore.

Preparation and Evaluation of a Microsponge Dermal Stratum Corneum Retention Drug Delivery System for Griseofulvin

Griseofulvin (GF) is used as an antifungal to treat superficial skin fungal infections such as tinea capitis and tinea pedis. Currently, GF is only available in traditional oral dosage forms and suffers from poor and highly variable bioavailability, hepatotoxicity, and long duration of treatment. Therefore, the main objective of this study was to reduce the side effects of the drug and to increase the concentration of the drug retained in the cutaneous stratum corneum (SC) and improve its efficacy through the preparation of drug-laden GF microsponge (GFMS). The emulsification-solvent-diffusion method was used to prepare GFMS, and the prescriptions were screened by a single-factor approach. The optimized formulation (GFF8) had a microsponge particle size (μm) of 28.36 ± 0.26, an encapsulation efficiency (%) of 87.53 ± 1.07, a yield (%) of 86.58 ± 0.42, and drug release (%) from 77.57 ± 3.88. The optimized microsponge formulation was then loaded into a Carbopol 934 gel matrix and skin retention differences between the microsponge gel formulation and normal gels were examined by performing skin retention and fluorescence microscopy tests. Finally, the hepatoprotective and cutaneous stratum corneum retention abilities of microsponge gel formulations compared to oral GF formulations were assessed by hepatotoxicity, pharmacokinetics, and tissue distribution studies. This provides a new perspective on GF dermal stratum corneum retention administration.

Investigating the Role of the Reduced Solubility of the Pirfenidone-Fumaric Acid Cocrystal in Sustaining the Release Rate from Its Tablet Dosage Form by Conducting Comparative Bioavailability Study in Healthy Human Volunteers

Pirfenidone (PFD) is the first pharmacological agent approved by the US Food and Drug Administration (FDA) in 2014 for the treatment of idiopathic pulmonary fibrosis (IPF). The recommended daily dosage of PFD in patients with IPF is very high (2403 mg/day) and must be mitigated through additives. In the present work, sustained-release (SR) formulations of the PFD-FA cocrystal of two different strengths such as 200 and 600 mg were prepared and its comparative bioavailability in healthy human volunteers was studied against the reference formulation PIRFENEX (200 mg). A single-dose pharmacokinetic study (200 mg IR vs 200 mg SR) demonstrated that the test formulation exhibited lower C_max and T_max in comparison to the reference formulation, which showed that the cocrystal behaved like an SR formulation. Further in the multiple-dose comparative bioavailability study (200 mg IR thrice daily vs 600 mg SR once daily), the test formulation was found bioequivalent to the reference formulation. In conclusion, the present study suggests that cocrystallization offers a promising strategy to reduce the solubility of PFD and opens the door for potential new dosage forms of this important pharmaceutical.

Therapeutic application of microsponges based drug delivery system

Microsponges delivery system (MDS) is highly porous, cross-linked based polymeric systems, that activates in the presence of temperature, rubbing and pH. MDS offers wide range of advantage, like controlled drug release, site-specific action, stable over a broad range of pH, poor irritation, cost effective, improved patient compliance. They can be transformed into various dosage forms like creams, gels, and lotions. MDS based system are suitable for treatment of topical disorders like acne, psoriasis, dandruff, eczema, scleroderma, hair loss, skin cancer, and other dreadful diseases. MDS application for drug delivery is not limited to topical drug delivery but also explored for oral, parenteral and pulmonary drug delivery. Microsponges were studied for colon targeting of drugs and genes. Additionally, MDS has wide application for sunscreen, cosmetics, and over the counter (OTC) products. Furthermore, MDS does not actuate any irritation, genotoxicity, immunogenicity or cytotoxicity. Therefore, this review extensively highlights about microsponges, their advantages, key factors affecting the micro-sponges' characteristics, the therapeutic application of microsponges in topical disorders, cancer, as cosmetics, recent advances in MDS and addresses the associated challenges.

Silver sulfadiazine loaded core-shell airbrushed nanofibers for burn wound healing application

Ideal dressing materials for complex and large asymmetric burns should have the dual properties of anti-bacterial and regenerative with advanced applicability of direct deposit on the wound at the patient bedside. In this study, core-shell nanofibers (polycaprolactone; PCL and polyethylene oxide; PEO) with different percent of silver sulfadiazine (SSD) loading (2-10%) were prepared by the airbrushing method using a custom build device. Results indicate a sustained release profile of silver sulfadiazine (SSD) up to 28 days and concentration-dependent anti-bacterial activity. The morphology and proliferation of human dermal fibroblast (HDF) cells and human dental follicle stem cells (HDFSC) on the silver sulfadiazine loaded nanofibers confirm the biocompatibility of airbrushed nanofibers. Moreover, upregulation of extracellular matrix (ECM) proteins (Col I, Col III, and elastin) support the differentiation and regenerative properties of silver sulfadiazine nanofiber mats. This was further confirmed by the complete recovery of rabbit burn wound models within 7 days of silver sulfadiazine loaded nanofiber dressing. Histopathology data show silver sulfadiazine loaded core-shell nanofibers' anti-inflammatory and proliferative activity without any adverse response on the tissue. Overall data display that the airbrushed silver sulfadiazine-loaded core-shell nanofibers are effective dressing material with the possibility of direct fiber deposition on the wound to cover, heal, and regenerate large asymmetric burn wounds.

Natural rubber dressing loaded with silver sulfadiazine for the treatment of burn wounds infected with Candida spp

Millions of people are burned worldwide every year and 265,000 of the cases are fatal. The development of burn treatment cannot consist only of the administration of a single drug. Due to the infection risk, antibiotics are used in conjunction with gels and damp bandages. In this work, an inexpensive curative based on silver sulfadiazine (SS) and natural rubber latex (NRL) was developed to treat burn wounds. It was produced by the casting method. The infrared spectrum presented no interaction between drug and biopolymer. At the same time, electronic micrographs showed that the SS crystals are inserted on the polymeric dressing surface. Mechanical properties after the drug incorporation were considered suitable for dermal application. About 32.4% of loaded SS was released in 192 h by the dressings that also inhibited the growth of Candida albicans and Candida parapsilosis at 75.0 and 37.5 μg·mL^-1, respectively. The curative proved to be biocompatible when applied to fibroblast cells, in addition to enhancing cellular proliferation and, in the hemocompatibility test, no hemolytic effects were observed. The good results in mechanical, antifungal and biological assays, combined with the average bandage cost of $0.10, represent an exciting alternative for treating burn wounds.

Sponge particulates for biomedical applications: Biofunctionalization, multi-drug shielding, and theranostic applications

Sponge particulates have attracted enormous attention in biomedical applications for superior properties, including large porosity, elastic deformation, capillary action, and three-dimensional (3D) reaction environment. Especially, the tiny porous structures make sponge particulates a promising platform for drug delivery, tissue engineering, anti-infection, and wound healing by providing abundant reservoirs of broad surface and internal network for cargo shielding and shuttling. To control the sponge-like morphology and improve the diversity of drug loading, some optimized preparation techniques of sponge particulates have been developed, contributing to the simplified preparation process and improved production reproducibility. Bio-functionalized strategies, including target modification, cell membrane camouflage, and hydrogel of sponge particulates have been applied to modulate the properties, improve the performance, and extend the applications. In this review, we highlight the unique physical properties and functions, current manufacturing techniques, and an overview of spongy particulates in biomedical applications, especially in inhibition of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infectivity. Moreover, the current challenges and prospects of sponge particulates are discussed rationally, providing an insight into developing vibrant fields of sponge particulates-based biomedicine.

bFGF and collagen matrix hydrogel attenuates burn wound inflammation through activation of ERK and TRK pathway

Burn injuries are most challenging to manage since it causes loss of the integrity of large portions of the skin leading to major disability or even death. Over the years, hydrogels are considered as a significant delivery system for wound treatment because of several advantages over other conventional formulations. We hypothesized that the bFGF-collagen-AgSD incorporated hydrogel formulation can accelerate the rate of burn healing in animal model and would promote fibroblast cell proliferation. Neovascularization and re-epithelialization is a hall mark of burn wound healing. In the present study, histopathological investigation and scanning electron microscopy of skin tissue of Wistar rats showed almost complete epithelialisation after 16 days in the treatment group. The developed hydrogel showed significantly accelerated wound closure compared with a standard and control group. The faster wound closure resulted from increased re-epithelialization and granulation tissue formation because of the presence of collagen and growth factor. Expressions of proteins such as TrkA, p- TrkA, ERK1/2, p-ERK1/2, NF-kβ, and p-NF-kβ involved in nerve growth factor (NGF) signalling pathway were analysed by western blot. All the findings obtained from this study indicated that the hydrogel can be considered as a promising delivery system against second degree burn by faster healing.

Formulation and evaluation of Ocimum basilicum-based emulgel for wound healing using animal model

The main aim of the topically applied drugs is to provide local drug contact to the skin and minimize general absorption of drugs. Ocimum basilicum (OB) is popular for folk medicines, having official acceptance in many countries. The aim of this study was to formulate and evaluate the efficacy of topical application of OB-based emulgel on wound healing in animal model. The prepared formulations (OB emulgel) were assessed for FTIR analysis, stability studies, physical appearance, rheological behavior, spreadability, patch/sensitivity test and in vitro drug release. The in vivo wound healing effect was evaluated and compared with commercially available Silver Sulfadiazine cream Quench® in wound-induced rabbits by macroscopic and histopathological evidence. The OB extract/drug was compatible with the selected polymer and other excipients and indicated the suitability of the polymers/excipients for preparation of topical emulgel. The formulated OB emulgel exhibited good physical properties. The release profile of emulgel was satisfactory and released 81.71 ± 1.7% of the drug in 250 min. In vivo wound healing studies showed that OB emulgel exhibited the highest percent wound contraction similar to the commercial product (p > 0.05). This activity was statistically significant (p < 0.05) in comparison to control. Histopathological assessment showed marked improvement in the skin histological architecture after 16 days of OB emulgel treatment. In conclusion, the data demonstrated here signify the prospective of 5% OB emulgel as an innovative therapeutic approach in wound healing.

The Effects of Silver Sulfadiazine on Methicillin-Resistant Staphylococcus aureus Biofilms

Methicillin-resistant Staphylococcus aureus (MRSA), the most commonly detected drug-resistant microbe in hospitals, adheres to substrates and forms biofilms that are resistant to immunological responses and antimicrobial drugs. Currently, there is a need to develop alternative approaches for treating infections caused by biofilms to prevent delays in wound healing. Silver has long been used as a disinfectant, which is non-specific and has relatively low cytotoxicity. Silver sulfadiazine (SSD) is a chemical complex clinically used for the prevention of wound infections after injury. However, its effects on biofilms are still unclear. In this study, we aimed to analyze the mechanisms underlying SSD action on biofilms formed by MRSA. The antibacterial effects of SSD were a result of silver ions and not sulfadiazine. Ionized silver from SSD in culture media was lower than that from silver nitrate; however, SSD, rather than silver nitrate, eradicated mature biofilms by bacterial killing. In SSD, sulfadiazine selectively bound to biofilms, and silver ions were then liberated. Consequently, the addition of an ion-chelator reduced the bactericidal effects of SSD on biofilms. These results indicate that SSD is an effective compound for the eradication of biofilms; thus, SSD should be used for the removal of biofilms formed on wounds.

Silver sulfadiazine loaded breathable hydrogel sponge for wound healing

Objectives Patients with serious injury need special care and treatment to control the infection, as wound sepsis is one of the major causes of death. Silver sulfadiazine (SSD) is widely used as an antimicrobial agent which promotes healing and re-epithelialization. However, due to certain drawbacks such as inflammation and cytotoxicity, the need for novel drug delivery modality emerges. The objective of this study was to develop natural polymeric (chitosan and gelatin) hydrogel sponges containing SSD and evaluate its efficacy in wound healing using animal models. Methods SSD containing hydrogel sponges were prepared by solvent casting technique. Scanning electron microscopy (SEM) and Differential scanning calorimetry (DSC) were used to evaluate morphological characteristics of the hydrogel sponges. Anti-thrombogenic property, drug release studies, drug release kinetics, antimicrobial property, and wound healing effect were also studied in detail. Results The optimized batch of hydrogel sponges (CG4) consists of 1% SSD wt., 10% wt. Gelatin, 1% wt. Chitosan and honey 7.5% wt. as plasticizer. At the 12th hour, in vitro and ex vivo drug release was found to be 76.994±0.67% and 24.22±0.57% respectively. CG4 batch had enhanced in vitro antimicrobial activity as compared to conventional marketed cream. The developed SSD hydrogel sponges showed a faster rate of wound healing as compared to a marketed cream. Animals treated with CG4 formulation showed complete angiogenesis and re-epithelialization by 8th day, whereas 12 days were required for complete wound healing with marketed cream. Conclusions The prepared hydrogel sponges can serve as a potential alternative for wound healing dressing as compared to the marketed product.

Hypertrophic scars and keloids: a review and current treatment modalities

Hypertrophic scars (HTS) are raised, red, rigid, inflexible cell-like, and cosmetic problems precipitated due to multiple underlying dermal injuries such as burn, surgery, and trauma during which aberrant wound healing with more pathological deposition of the extracellular matrix than degradation leads to their spawning. Till date, well established and specific treatments for HTS have not been reported; hence, the need of recent developments is thrusted with novel drug delivery vision. This review will try to encompass all the agogs to HTS, definition, pathophysiology, mechanism of hypertrophic scar formation, the role of growth factors in hypertrophic scarring, and their difference with keloids. Further, it will illuminate the available medicaments and recent advances in novel topical drug delivery systems such as ethosomes, transethosomes, liposomes, solid lipid nanoparticles, and microsponges for treatment of HTS.

Microsponges for dermatological applications: Perspectives and challenges

Dermatological disorders have a huge psychosocial impact, causing significant impairment of patient's life. Topical therapy plays a pivotal role in management of such disorders. Conventional topical delivery systems result in overmedication/undermedication, leading to adverse effects and reduction in therapeutic efficacy. Consequently, researchers have been striving towards the development of alternative delivery systems for dermatological applications. In the last decade, microsponges emerged as an attractive option for topical delivery. Their characteristic particle size offers enhanced benefits, making them superior to the contemporary microcarriers. The present review furnishes a comprehensive account of state of the art, important factors affecting the performance and mechanism of drug release from topically applied microsponges, along with characterization techniques. Further, a list of marketed products and their applications for common dermatological disorders has been presented. All in all, this paper is an attempt to lay a bibliographic foundation for researchers working in this field and foster further investigations in this arena.

Ecofriendly Ethyl Cellulose Microsponges of Citronella Oil: Preparation, Characterization and Evaluation of Cytotoxicity and Larvicidal assay

Background:

Citronella Oil (CO) was used by the Indian army as mosquito repellant to repel mosquitoes at the beginning of the 20th century and later in 1948, it was registered in the USA for commercial purposes. Due to its ecofriendly nature, CO possesses immense potential as a mosquito repellent.

Methods:

Citronella oil is a valuable alternative to synthetic mosquito repellents commonly used nowadays. However, its volatile nature, poor stability in air and high temperature restrict its application. Its direct application on skin may lead to skin irritation. To surmount the above-mentioned issues, the present research aims to develop Microsponge (MS), a novel dosage form for enhancing the utility and safety of CO. Quasi emulsion solvent diffusion method was chosen for crafting MS using ethyl cellulose with various drug-polymer ratios and characterized. In vitro cytotoxicity evaluation was also carried out to check the dermal safety of COMS.

Results:

The present results revealed that the size of all prepared formulation lies in the micro range (20 ± 3 to 41 ± 4 μm), with good payload (42.09± 3.24 to 67.08± 6.43%). The results of FE-SEM depicted that MS were spherical in shape with porous nature. Cytotoxicity results indicated that COMS were safe on skin cells, when compared to pure CO. The optimized MS were also assessed for larvicidal assay against larvae of Anopheles culicifacies.

Conclusion:

The CO micro-formulations were found to possess enhanced stability of this oil. Entrapment of CO in MS resulted in a better vehicle system in terms of safety, stability and handling benefits of this oil.

Searching for Bacteria in Neural Tissue From Amyotrophic Lateral Sclerosis

Despite great efforts in the investigation, the exact etiology of amyotrophic lateral sclerosis (ALS) is a matter of intensive research. We recently advanced the idea that ALS might be caused by fungal infection. Indeed, fungal yeast and hyphal structures can be directly visualized in neural tissue of ALS patients, and a number of fungal species have been identified in the central nervous system (CNS). In the present work, we tested the possibility that bacterial infections can accompany these mycoses. Our findings establish the presence of bacterial DNA in different regions of the CNS from all ALS patients examined. Specifically, we used PCR and next generation sequencing (NGS) to precisely determine the bacterial species present in ALS tissue. Consistent with these findings, immunohistochemistry analysis of CNS sections using specific anti-bacterial antibodies identified prokaryotic cells in neural tissue. Finally, we assayed for the repeat expansion of the hexanucleotide repeat GGGGCC in C9orf72, which is considered the most common genetic cause of ALS in patients, using DNA extracted from ALS CNS tissue. We failed to find this repeated sequence in any of the eleven patients analyzed. Our results indicate that bacterial DNA and prokaryotic cells are present in CNS tissue, leading to the concept that both fungal and bacterial infections coexist in patients with ALS. These observations lay the groundwork for the use of appropriate therapies to eradicate the polymicrobial infections in ALS.

Protective effects of polyphenolic extracts from longan seeds promote healing of deep second-degree burn in mice

The objective of this study was to evaluate the ability of a polyphenolic extract from longan seeds as a wound-healing material for deep second-degree burn wounds.

Silver sulfadiazine nanosuspension-loaded thermosensitive hydrogel as a topical antibacterial agent

Background

Silver sulfadiazine (AgSD) is widely employed as an antibacterial agent for surface burn management. However, the antibacterial activity of AgSD was restrained because of the lower drug solubility and possible cytotoxicity.

Objective

This study aimed to formulate stable silver sulfadiazine/nanosuspensions (AgSD/NSs) with improved AgSD solubility and prepare a suitable carrier for AgSD/NS delivery. Nanotechnology was used to overcome the low drug dissolution rate of AgSD, while the new carrier loaded with AgSD/NS was assumed to decrease the possible cytotoxicity, enhance antibacterial activity, and promote wound healing.

Methods

AgSD/NSs were prepared by high pressure homogenization method. Poloxamer 407-based thermoresponsive hydrogels were prepared by cold method as carriers of AgSD/NS to obtain AgSD/NS-loaded thermoresponsive hydrogel. Scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) were used to measure the physicalchemical properties of AgSD/NSs and AgSD/NS-loaded gel. The cytotoxicity of the AgSD/NS-loaded gel was evaluated using methyl thiazolyltetrazolium assay with L929 mouse fibroblast cell lines. In vitro antibacterial activities of AgSD/NSs and AgSD/NS loaded gel were also measured.

Results

Stable AgSD/NSs with an average particle size of 369 nm were formulated while 1.5% P407 was selected as a stabilizer. The optimized AgSD/NS thermoresponsive hydrogel exhibited the gelation temperature of approximately 30°C. A significant improvement in solubility was observed for AgSD nanoparticles (96.7%) compared with AgSD coarse powders (12.5%). The results of FTIR and XRD revealed that the physicochemical properties of AgSD/NS were reserved after incorporating into the hydrogel. The cell viability after incubation with AgSD/NS-loaded thermoresponsive hydrogel improved from 60.7% to 90.6% compared with incubation with AgSD/NS directly. Drug release profiles from the thermoresponsive hydrogel increased compared with the commercial AgSD cream, implying less application frequency of AgSD cream clinically. In vitro antibacterial studies manifested that AgSD nanocrystallization significantly enhanced the antibacterial activity compared with the AgSD coarse powder.

Conclusion

The combination of AgSD nanosuspensions and thermoresponsive hydrogel effectively improved the AgSD antibacterial activity and decreased the cytotoxicity. This study also suggested that a poloxamer thermoresponsive hydrogel could be used as a delivery system for other nanocrystals to decrease possible nanotoxicity.

Therapeutically Effective Controlled Release Formulation of Pirfenidone from Nontoxic Biocompatible Carboxymethyl Pullulan-Poly(vinyl alcohol) Interpenetrating Polymer Networks

The present study was conducted to develop therapeutically effective controlled release formulation of pirfenidone (PFD) and explore the possibility to reduce the total administered dose and dosing regimen. For this purpose, pH-sensitive biomaterial was prepared by inducing carboxymethyl group on pullulan by Williamson ether synthesis reaction, and further, interpenetrating polymeric network microspheres were prepared by glutaraldehyde-assisted water-in-oil (w/o) emulsion cross-linking method, which showed higher swelling ratio in acidic and basic pH. The formation of microspheres was confirmed by different spectral characterization techniques, and thermal kinetic study indicated the formation of thermally stable microspheres. Cell viability and biocompatibility studies on hepatocellular carcinoma (HepG2) cell showed the polymeric matrix to be biocompatible. In vitro dissolution of optimized formulation (F5) showed releases of 54.09 and 76.37% in 0.1 N HCl after 2 h and phosphate buffer (pH 6.8) up to 8 h, respectively. In vivo performances of prepared microsphere and marketed product of PFD were compared in rabbit. T max (time taken to reach peak plasma concentration) was found to be achieved at 0.83 h, compared to 0.5 h for Pirfenex with no significant difference complementing the immediate action, while area under curve was significantly greater for optimized formulation (9768 ± 1300 ng h/mL) compared to Pirfenex (4311 ± 110 ng h/mL), complementing the sustained action. In vivo pharmacokinetic study suggested that the prepared microsphere could be a potential candidate for therapeutically effective controlled delivery of PFD used in dyspnea and cough management due to idiopathic pulmonary fibrosis.

Formulation and evaluation of curcumin microsponges for oral and topical drug delivery

The aim of the present study was to improve the release rate of curcumin by microsponges prepared through quasi-emulsion solvent diffusion technique using ethylcellulose and PVA as carriers. The microsponges were characterized by FTIR, DSC, XRD and SEM studies followed by determination of total drug content and entrapment efficiency. The prepared microsponges were further filled in hard gelatin capsule shell and then loaded in carbopol gel to evaluate its potential in oral and topical drug delivery. Further, it was observed from the studies on release rate that microsponges filled in hard gelatin capsule shells (batch MS4) showed 93.2% release of curcumin whereas pure curcumin filled in capsule showed only 11.7% release in 8 h study. Furthermore, the microsponges loaded in carbopol gel were evaluated for ex vivo drug deposition studies and it was found that 77.5% of the curcumin was released within 24 h. The estimated drug remained in the skin was 207.61 ± 5.03 μg/cm2 as determined by a Franz diffusion cell. The drug release profile data were found to be fitted best into the zero-order model with anomalous transport mechanism of drug release in both cases.

Encapsulation of babchi essential oil into microsponges: Physicochemical properties, cytotoxic evaluation and anti-microbial activity

Babchi essential oil (BEO) is a valuable essential oil reported to possess a variety of biological activities such as antitumor, anti inflammatory, immunomodulatory, antioxidant, antifungal and antibacterial properties. Due to its anti-microbial properties, this oil possesses an immense potential for the treatment of dermatological disorders. Further, it has minimal tendency to develop resistance, a common issue with most of the antibiotics. However, its highly viscous nature and poor stability in the presence of light, air and high temperature, limits its practical applications. To surmount these issues, this research aims to encapsulate BEO in ethyl cellulose (EC) microsponges for enhanced stability, antibacterial effect and decreased dermal toxicity. The quasi emulsion solvent evaporation technique was used for fabrication of the BEO microsponges employing EC as polymer, polyvinyl alcohol (PVA) as stabilizer and dichloro methane (DCM) as solvent. The effect of formulation variables such as the amount of EC and PVA were also investigated. The prepared microformulations were evaluated for production yield, encapsulation efficiency, particle size and in vitro release. In vitro cytotoxicity was also checked to assess dermal safety of BEO microsponges. Results revealed that all the dispersions were in micro size range (20.44 ± 3.13 μmto 41.75 ± 3.65 μm), with good encapsulation efficiency (87.70 ± 1.20% of F2) and controlled release profile (cumulative drug release 73.34 ± 1.76%). Field emission scanning electron microscopy results showed that the microsponges possessed a spherical uniform shape with a spongy structure. Results of cytotoxicity study indicated that the prepared microsponges were safer on dermal cells in comparison to pure BEO. The optimized formulation was also evaluated for in vitro antimicrobial assay against dermal bacteria like Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli, which confirmed their enhanced antibacterial activity. Furthermore, the results of photostability and stability analysis indicated improved stability of BEO loaded microsponges. Hence, encapsulation of BEO in microsponges resulted in efficacious carrier system in terms of stability as well as safety of this essential oil along with handling benefits.

Optimization of reaction conditions to fabricate Ocimum sanctum synthesized silver nanoparticles and its application to nano-gel systems for burn wounds

The present study deals with sequential optimization strategy based on Box-Behnken method to optimize the process variables for efficient production of Ocimum sanctum synthesized silver nanoparticles using biological synthesis. Four substantial factors influencing the dependent variables viz size, zeta potential, Polydispersity index (PDI) and yield were identified as silver nitrate concentration, temperature, amount of plant extract and stirring speed as independent variables. The contribution of the studied factors in monitoring dependent variables was evaluated via analysis of variance. The validity of the model developed was verified, and the statistical analysis showed that the optimal operational conditions were AgNO₃ concentration 5.29 mM, temperature 60 °C, agitation speed of 500 rpm and plant extract 2.24% (w/v) which primes to form silver nanoparticles of smallest size 83.41 nm and 0.24 with maximum zeta potential of -20.20mV and Yield of 18.62. In addition, the optimized AgNPs were characterized using DLS, TEM, FE-SEM and UV-vis analysis. The topical formulation was prepared by incorporation of optimized AgNPs into the carbopol gel base. Further, the gel was evaluated in vivo using the rat model of skin wound healing. The measurement of the wound areas was performed on 2nd, 4th, 6th, 8th, 10th, 12th and 14th days and the percentage of wound closures were calculated accordingly. By the 14th day, silver nanoparticle gel showed 96.20% wound healing activity compared with that of the standard as well as control base. The antibacterial inhibitory efficiency of prepared nano gel was found similar to the commercial product against the Staphylococcus aureus, E. coli and Pseudomonas aeruginosa.

Preparation and Characterization of Silver Sulfadiazine-Loaded Polyvinyl Alcohol Hydrogels as an Antibacterial Wound Dressing

In this study, we prepared a series of silver sulfadiazine (AgSD)-loaded polyvinyl alcohol (PVA) hydrogels via electron beam (e-beam) irradiation. Our objective was to explore the influence of e-beam irradiation on the chemical structure and crystallinity of AgSD and the antibacterial properties of AgSD/PVA hydrogels. Prior to irradiation, we mixed AgSD in PVA solution in 2 forms, either suspended in water (WS) or dissolved in ammonia solution (AS). We noted that nano silver was released from AgSD/PVA-AS hydrogels immersed in deionized water, while it would not happen in AgSD/PVA-WS hydrogels. Both kinds of AgSD/PVA hydrogels exhibited good antibacterial activities against gram-negative Escherichia coli and gram-positive Staphylococcus aureus. And their antibacterial activity was not obviously affected by different dosages of e-beam irradiation. Moreover, the antibacterial activity of the AgSD/PVA-WS hydrogels was stronger than that of AgSD/PVA-AS. Accordingly, the cell cytotoxicity of the AgSD/PVA-WS hydrogels was higher than that of AgSD/PVA-AS. Our study results reveal that e-beam irradiation of PVA solution with dispersed AgSD is a simple and efficient way to prepare AgSD/PVA hydrogels, which might be an ideal antibacterial wound dressing.

A Review About the Drug Delivery from Microsponges

Microparticulate drug delivery systems have shown a great interest in the pharmaceutical area. They allow the increase of drug therapeutic efficacy and the reduction of side effects. In this context, microsponges represent a new model of porous polymer microspheres, which allow the entrapment of a wide range of active agents. During the development, it is necessary the characterization of the system and among of the most important tests are the release and permeation profile analysis. They can demonstrate the behavior of drug in a specific site with a particular application condition and are related to therapeutic efficacy. Therefore, this review provides an overview of drug delivery profile from microsponges. Methods for determination of in vitro release and ex vivo permeation studies are detailed. Examples of drug delivery from microsponges administered in different sites are also discussed with aim to provide an understanding of the use of this strategy to modify the drug delivery.

Cationic-bilayered nanoemulsion of fusidic acid: an investigation on eradication of methicillin-resistant Staphylococcus aureus 33591 infection in burn wound

AIM

The aim of the current study was to investigate the therapeutic efficacy of cationic-charged bilayered nanoemulsion for topical delivery of fusidic acid in eradicating methicillin-resistant Staphylococcus aureus (MRSA) bacterial burn wound infection.

MATERIALS & METHODS

The developed carriers were characterized for particle size, antibacterial activity, cell viability assay in HaCat cell lines, rheological profile, ex vivo and in vivo studies, namely, full thickness MRSA 33591 murine burn wound infection via topical route.

RESULTS

The developed cationic bilayered nanogel offered enhanced drug permeation, reduction in bacterial load and enhanced wound contraction along with faster re-epithelialization in burn wounds.

CONCLUSION

The results encourage the exploration of the potential of cationic nanogel in treating resistant microorganisms such as MRSA, especially for application in burn wound infection.