Hydrogels containing soybean isoflavone aglycones-rich fraction-loaded nanoemulsions for wound healing treatment - in vitro and in vivo studies

Development and Investigation of a Nanoemulgel Formulated from Tunisian Opuntia ficus-indica L. Seed Oil for Enhanced Wound Healing Activity

The aim of this study is to develop a nanoemulgel encapsulating a Tunisian Prickly Pear (Opuntia ficus-indica L.) seed oil (PPSO) to assess, for the first time, the in vivo efficacy of this nanoformulation on wound healing. Phytocompounds of this oil have been reported in the literature as having powerful pharmacological activities. However, it remains poorly exploited due to low bioavailability. A nanoemulsion (NE) was designed by determining the required hydrophilic-lipophilic balance (HLB) and subsequently characterized. The mean droplet size was measured at 56.46 ± 1.12 nm, with a polydispersity index (PDI) of 0.23 ± 0.01 using dynamic light scattering. The zeta potential was -31.4 ± 1.4 mV, and the morphology was confirmed and assessed using transmission electron microscopy (TEM). These characteristics align with the typical properties of nanoemulsions. The gelification process resulted in the formation of a nanoemulgel from the optimum nanoemulsion. The high wound healing efficiency of the nanoemulgel was confirmed compared to that of a medicinally marketed cream. The outcomes of this research contribute valuable insights, for the first time, into the potential therapeutic applications of PPSO and its innovative pharmaceutical formulation for wound healing.

Augmented ocular uptake and anti-inflammatory efficacy of decorated Genistein-loaded NLCs incorporated in in situ gel

Genistein (Gen); a naturally occurring isoflavone, acts as a tyrosine kinase inhibitor and efficiently downregulates inflammatory cytokines, which are pivotal in eye inflammation. Also, Gen suffers from sparse ocular bioavailability due to poor solubility. In this work, nanostructured lipid carriers (NLCs) were successfully fabricated by using solid (stearic acid and compritol) and liquid (oleic acid) lipids. The optimized Gen-loaded NLCs showed a nanosize range of 140-246 nm, ≥ 98 % entrapment efficiency, and controlled release over 48 h. The ζ-potential of NLCs was increased from -27.3 mV to 25-27.4 mV due to surface modification with chitosan (CS) or eudragit RS100 (ERS 100). All NLCs showed prominent biocompatibility with enhanced cellular uptake on corneal stromal fibroblasts. Moreover, the different NLCs were incorporated into a mucoadhesive in situ gel. The optimized in situ gel (G9), containing 20 % poloxamers and 0.5 % hydroxyethyl cellulose, exhibited excellent gelling ability within 10.5 s, gelling temperature at 33.1 ± 0.6 ℃, spreadability diameter of 4.73 ± 0.12 cm, shear-thinning behavior, and 20 min ex vivo mucoadhesion time with drug release for 120 h. The in vivo results showed distinguished permeation and distribution potential for ocular delivery. In vivo anti-inflammatory effects after 3 days of treatment with CS-Gen-NLCs/G9 and ERS-Gen-NLCs/G9 revealed a downregulation of interleukin-6 levels in the cornea and retina compared to the untreated group. Our research highlights the promising anti-inflammatory potential of ERS-Gen-NLCs/G9 as an efficient, non-irritant Gen nanodelivery system for managing anterior and posterior ocular inflammation.

Greener healing: sustainable nanotechnology for advanced wound care

Wound healing involves a carefully regulated sequence of events, encompassing pro-inflammatory and anti-inflammatory stages, tissue regeneration, and remodeling. However, in individuals with diabetes, this process gets disrupted due to dysregulation caused by elevated glucose levels and pro-inflammatory cytokines in the bloodstream. Consequently, the pro-inflammatory stage is prolonged, while the anti-inflammatory phase is delayed, leading to impaired tissue regeneration and remodeling with extended healing time. Furthermore, the increased glucose levels in open wounds create an environment conducive to microbial growth and tissue sepsis, which can escalate to the point of limb amputation. Managing diabetic wounds requires meticulous care and monitoring due to the lack of widely available preventative and therapeutic measures. Existing clinical interventions have limitations, such as slow recovery rates, high costs, and inefficient drug delivery methods. Therefore, exploring alternative avenues to develop effective wound-healing treatments is essential. Nature offers a vast array of resources in the form of secondary metabolites, notably polyphenols, known for their antimicrobial, anti-inflammatory, antioxidant, glucose-regulating, and cell growth-promoting properties. Additionally, nanoparticles synthesized through environmentally friendly methods hold promise for wound healing applications in diabetic and non-diabetic conditions. This review provides a comprehensive discussion and summary of the potential wound-healing abilities of specific natural polyphenols and their nanoparticles. It explores the mechanisms of action underlying their efficacy and presents effective formulations for promoting wound-healing activity.

OxInflammatory Responses in the Wound Healing Process: A Systematic Review

Significant sums are spent every year to find effective treatments to control inflammation and speed up the repair of damaged skin. This study investigated the main mechanisms involved in the skin wound cure. Consequently, it offered guidance to develop new therapies to control OxInflammation and infection and decrease functional loss and cost issues. This systematic review was conducted using the PRISMA guidelines, with a structured search in the MEDLINE (PubMed), Scopus, and Web of Science databases, analyzing 23 original studies. Bias analysis and study quality were assessed using the SYRCLE tool (Prospero number is CRD262 936). Our results highlight the activation of membrane receptors (IFN-δ, TNF-α, toll-like) in phagocytes, especially macrophages, during early wound healing. The STAT1, IP3, and NF-kβ pathways are positively regulated, while Ca2+ mobilization correlates with ROS production and NLRP3 inflammasome activation. This pathway activation leads to the proteolytic cleavage of caspase-1, releasing IL-1β and IL-18, which are responsible for immune modulation and vasodilation. Mediators such as IL-1, iNOS, TNF-α, and TGF-β are released, influencing pro- and anti-inflammatory cascades, increasing ROS levels, and inducing the oxidation of lipids, proteins, and DNA. During healing, the respiratory burst depletes antioxidant defenses (SOD, CAT, GST), creating a pro-oxidative environment. The IFN-δ pathway, ROS production, and inflammatory markers establish a positive feedback loop, recruiting more polymorphonuclear cells and reinforcing the positive interaction between oxidative stress and inflammation. This process is crucial because, in the immune system, the vicious positive cycle between ROS, the oxidative environment, and, above all, the activation of the NLRP3 inflammasome inappropriately triggers hypoxia, increases ROS levels, activates pro-inflammatory cytokines and inhibits the antioxidant action and resolution of anti-inflammatory cytokines, contributing to the evolution of chronic inflammation and tissue damage.

Toward a Platform for the Treatment of Burns: An Assessment of Nanoemulsions vs. Nanostructured Lipid Carriers Loaded with Curcumin

Curcumin is a highly promising substance for treating burns, owing to its anti-inflammatory, antioxidant, antimicrobial, and wound-healing properties. However, its therapeutic use is restricted due to its hydrophobic nature and low bioavailability. This study was conducted to address these limitations; it developed and tested two types of lipid nanocarriers, namely nanoemulsions (NE-CUR) and nanostructured lipid carriers (NLC-CUR) loaded with curcumin, and aimed to identify the most suitable nanocarrier for skin burn treatment. The study evaluated various parameters, including physicochemical characteristics, stability, encapsulation efficiency, release, skin permeation, retention, cell viability, and antimicrobial activity. The results showed that both nanocarriers showed adequate size (~200 nm), polydispersity index (~0.25), and zeta potential (~>-20 mV). They also showed good encapsulation efficiency (>90%) and remained stable for 120 days at different temperatures. In the release test, NE-CUR and NCL-CUR released 57.14% and 51.64% of curcumin, respectively, in 72 h. NE-CUR demonstrated better cutaneous permeation/retention in intact or scalded skin epidermis and dermis than NLC-CUR. The cell viability test showed no toxicity after treatment with NE-CUR and NLC-CUR up to 125 μg/mL. Regarding microbial activity assays, free curcumin has activity against P. aeruginosa, reducing bacterial growth by 75% in 3 h. NE-CUR inhibited bacterial growth by 65% after 24 h, and the association with gentamicin had favorable results, while NLC-CUR showed a lower inhibition. The results demonstrated that NE-CUR is probably the most promising nanocarrier for treating burns.

Multifunctional and theranostic hydrogels for wound healing acceleration: An emphasis on diabetic-related chronic wounds

Hydrogels represent intricate three-dimensional polymeric structures, renowned for their compatibility with living systems and their ability to naturally degrade. These networks stand as promising and viable foundations for a range of biomedical uses. The practical feasibility of employing hydrogels in clinical trials has been well-demonstrated. Among the prevalent biomedical uses of hydrogels, a significant application arises in the context of wound healing. This intricate progression involves distinct phases of inflammation, proliferation, and remodeling, often triggered by trauma, skin injuries, and various diseases. Metabolic conditions like diabetes have the potential to give rise to persistent wounds, leading to delayed healing processes. This current review consolidates a collection of experiments focused on the utilization of hydrogels to expedite the recovery of wounds. Hydrogels have the capacity to improve the inflammatory conditions at the wound site, and they achieve this by diminishing levels of reactive oxygen species (ROS), thereby exhibiting antioxidant effects. Hydrogels have the potential to enhance the growth of fibroblasts and keratinocytes at the wound site. They also possess the capability to inhibit both Gram-positive and Gram-negative bacteria, effectively managing wounds infected by drug-resistant bacteria. Hydrogels can trigger angiogenesis and neovascularization processes, while also promoting the M2 polarization of macrophages, which in turn mitigates inflammation at the wound site. Intelligent and versatile hydrogels, encompassing features such as pH sensitivity, reactivity to reactive oxygen species (ROS), and responsiveness to light and temperature, have proven advantageous in expediting wound healing. Furthermore, hydrogels synthesized using environmentally friendly methods, characterized by high levels of biocompatibility and biodegradability, hold the potential for enhancing the wound healing process. Hydrogels can facilitate the controlled discharge of bioactive substances. More recently, there has been progress in the creation of conductive hydrogels, which, when subjected to electrical stimulation, contribute to the enhancement of wound healing. Diabetes mellitus, a metabolic disorder, leads to a slowdown in the wound healing process, often resulting in the formation of persistent wounds. Hydrogels have the capability to expedite the healing of diabetic wounds, facilitating the transition from the inflammatory phase to the proliferative stage. The current review sheds light on the biological functionalities of hydrogels, encompassing their role in modulating diverse mechanisms and cell types, including inflammation, oxidative stress, macrophages, and bacteriology. Additionally, this review emphasizes the significance of smart hydrogels with responsiveness to external stimuli, as well as conductive hydrogels for promoting wound healing. Lastly, the discussion delves into the advancement of environmentally friendly hydrogels with high biocompatibility, aimed at accelerating the wound healing process.

Potential of nanoemulsions for accelerated wound healing: innovative strategies

Wounds represent various significant health concerns for patients and also contribute major costs to healthcare systems. Wound healing comprises of overlapped and various coordinated steps such as homeostasis, inflammation, proliferation, and remodeling. In response to the failure of many strategies in delivering intended results including wound closure, fluid loss control, and exhibiting properties such as durability, targeted delivery, accelerated action, along with histocompatibility, numerous nanotechnological advances have been introduced. To understand the magnitude of wound therapy, this systematic and updated review discussing the effectiveness of nanoemulsions has been undertaken. This review portrays mechanisms associated with wound healing, factors for delayed wound healing, and various technologies utilized to treat wounds effectively. While many strategies are available, nanoemulsions have attracted the tremendous attention of scientists globally for the research in wound therapy due to their long-term thermodynamic stability and bioavailability. Nanoemulsions not only aid in tissue repair, but are also considered as an excellent delivery system for various synthetic and natural actives. Nanotechnology provides several pivotal benefits in wound healing, including improved skin permeation, controlled release, and stimulation of fibroblast cell proliferation. The significant role of nanoemulsions in improved wound healing along with their preparation techniques has also been highlighted with special emphasis on mechanistic insights. This article illustrates recent research advancements for the utilization of nanoemulsions in wound treatment. An adequate literature search has been conducted using the keywords 'Nanoemulsions in wound healing', 'Wound therapy and nanoemulsions', 'Herbal actives in wound therapy', 'Natural oils and wounds treatment' etc., from PubMed, Science Direct, and Google Scholar databases. Referred and original publications in the English language accessed till April 2022 has been included, whereas nonEnglish language papers, unpublished data, and nonoriginal papers were excluded from the study.

Status and Future Scope of Soft Nanoparticles-Based Hydrogel in Wound Healing

Wounds are alterations in skin integrity resulting from any type of trauma. The healing process is complex, involving inflammation and reactive oxygen species formation. Therapeutic approaches for the wound healing process are diverse, associating dressings and topical pharmacological agents with antiseptics, anti-inflammatory, and antibacterial actions. Effective treatment must maintain occlusion and moisture in the wound site, suitable capacity for the absorption of exudates, gas exchange, and the release of bioactives, thus stimulating healing. However, conventional treatments have some limitations regarding the technological properties of formulations, such as sensory characteristics, ease of application, residence time, and low active penetration in the skin. Particularly, the available treatments may have low efficacy, unsatisfactory hemostatic performance, prolonged duration, and adverse effects. In this sense, there is significant growth in research focusing on improving the treatment of wounds. Thus, soft nanoparticles-based hydrogels emerge as promising alternatives to accelerate the healing process due to their improved rheological characteristics, increased occlusion and bioadhesiveness, greater skin permeation, controlled drug release, and a more pleasant sensory aspect in comparison to conventional forms. Soft nanoparticles are based on organic material from a natural or synthetic source and include liposomes, micelles, nanoemulsions, and polymeric nanoparticles. This scoping review describes and discusses the main advantages of soft nanoparticle-based hydrogels in the wound healing process. Herein, a state-of-the-art is presented by addressing general aspects of the healing process, current status and limitations of non-encapsulated drug-based hydrogels, and hydrogels formed by different polymers containing soft nanostructures for wound healing. Collectively, the presence of soft nanoparticles improved the performance of natural and synthetic bioactive compounds in hydrogels employed for wound healing, demonstrating the scientific advances obtained so far.

Combined Orobol-Bentonite Composite Formulation for Effective Topical Skin Targeted Therapy in Mouse Model

Purpose

Orobol is an isoflavone that has a potent skin protection effect. The objective of this study was to prepare a novel bentonite-based composite formulation of orobol to enhance topical skin delivery.

Methods

The composition was optimized based on the orobol content in the composite and the in vitro release studies, followed by the in vitro and in vivo hairless mouse skin deposition studies. Physicochemical characterizations of the composite formulation were performed by powder X-ray refractometry (XRD) and scanning electron microscopy (SEM). The in vitro cytotoxicity and in vivo toxicity studies were conducted in human keratinocytes and in hairless mouse, respectively.

Results and Discussions

The in vitro release of orobol from the bentonite composites was higher than that from the suspension, which was further increased with the addition of phosphatidylcholine. The composite formulation significantly enhanced the in vitro and in vivo skin deposition of orobol in hairless mouse skin compared to the orobol suspension. Moreover, the addition of phosphatidyl choline not only improved the dissolution and incomplete release of orobol from the bentonite composite but also enhanced the deposition of orobol in the skin. XRD histograms and SEM images confirmed that the enhanced dissolution of orobol from the composite was attributed to its amorphous state on bentonite. The in vitro and in vivo toxicity studies support the safety and biocompatibility of the orobol-loaded bentonite composite formulation.

Conclusion

These findings suggest that the orobol-loaded bentonite composite formulation could be a potential topical skin delivery system for orobol.

Neem Oil or Almond Oil Nanoemulsions for Vitamin E Delivery: From Structural Evaluation to in vivo Assessment of Antioxidant and Anti-Inflammatory Activity

Purpose

Vitamin E (VitE) may be classified in "the first line of defense" against the formation of reactive oxygen species. Its inclusion in nanoemulsions (NEs) is a promising alternative to increase its bioavailability. The aim of this study was to compare O/W NEs including VitE based on Almond or Neem oil, showing themselves antioxidant properties. The potential synergy of the antioxidant activities of oils and vitamin E, co-formulated in NEs, was explored.

Patients and Methods

NEs have been prepared by sonication and deeply characterized evaluating size, ζ-potential, morphology (TEM and SAXS analyses), oil nanodroplet feature, and stability. Antioxidant activity has been evaluated in vitro, in non-tumorigenic HaCaT keratinocytes, and in vivo through fluorescence analysis of C. elegans transgenic strain. Moreover, on healthy human volunteers, skin tolerability and anti-inflammatory activity were evaluated by measuring the reduction of the skin erythema induced by the application of a skin chemical irritant (methyl-nicotinate).

Results

Results confirm that Vitamin E can be formulated in highly stable NEs showing good antioxidant activity on keratinocyte and on C. elegans. Interestingly, only Neem oil NEs showed some anti-inflammatory activity on healthy volunteers.

Conclusion

From the obtained results, Neem over Almond oil is a more appropriate candidate for further studies on this application.

Design and Investigation of an Eco-Friendly Wound Dressing Composed of Green Bioresources- Soy Protein, Tapioca Starch, and Gellan Gum

In the fields of biomedicine and tissue engineering, natural polymer-based tissue-engineered scaffolds are used in multiple applications. As a plant-derived polymer, soy protein, containing multiple amino acids, is structurally similar to components of the extra-cellular matrix (ECM) of tissues. It is biological safety provided a good potential to be material for pure natural scaffolds. Moreover, as a protein, the properties of soy protein can be easily adjusted by modifying the functional groups on it. In addition, by blending soy protein with other synthetic and natural polymers, the mechanical characteristics and bioactive behavior of scaffolds can be facilitated for a variety of bio-applications. In this research, soy protein and polysaccharides tapioca starch are used, and gellan gum to develop a protein-based composite scaffold for cell engineering. The morphology and surface chemical composition are characterized via micro-computed tomography (micro-CT), scanning electron microscope (SEM), and fourier-transform infrared (FTIR) spectroscopy. The soy/tapioca/gellan gum (STG) composite scaffolds selectively help the adhesion and proliferation of L929 fibroblast cells while improving the migration of L929 fibroblast cells in STG composite scaffolds as the increase of soy protein proportion of the scaffold. In addition, STG composite scaffolds show great potential in the wound healing model to enhance rapid epithelialization and tissue granulation.

The potential of functionalized dressing releasing flavonoids facilitates scar-free healing

Scars are pathological marks left after an injury heals that inflict physical and psychological harm, especially the great threat to development and aesthetics posed by oral and maxillofacial scars. The differential expression of genes such as transforming growth factor-β, local adherent plaque kinase, and yes-related transcriptional regulators at infancy or the oral mucosa is thought to be the reason of scarless regenerative capacity after tissue defects. Currently, tissue engineering products for defect repair frequently overlook the management of postoperative scars, and inhibitors of important genes alone have negative consequences for the organism. Natural flavonoids have hemostatic, anti-inflammatory, antioxidant, and antibacterial properties, which promote wound healing and have anti-scar properties by interfering with the transmission of key signaling pathways involved in scar formation. The combination of flavonoid-rich drug dressings provides a platform for clinical translation of compounds that aid in drug disintegration, prolonged release, and targeted delivery. Therefore, we present a review of the mechanisms and effects of flavonoids in promoting scar-free regeneration and the application of flavonoid-laden dressings.

The effectiveness of synthetic methoxylated isoflavones in delivering to the skin and alleviating psoriasiform lesions via topical absorption

This study was conducted to appraise the possible potential of synthetic isoflavones (SIFs) on psoriasis treatment. A practical and easy-to-operate approach was employed in synthesizing a series of SIFs, considering that acquiring flavonoids from natural resources is usually expensive, time-consuming, and non-eco-friendly. Seven SIFs derived from daidzein were produced with differences in the location of the hydroxyl groups and degree of methoxylation. The in vitro and in vivo skin absorption of topically applied SIFs was estimated. Further, keratinocytes (HaCaT) were employed as the model to investigate the anti-inflammatory activity of the isoflavones. The lipophilicity was increased from SIF-1 to -7. Noteworthily, there was a parabolic relationship between lipophilicity and skin absorption, with SIF-5 (4',7-dihydroxyisoflavone, daidzein) and SIF-6 (7-hydroxy-3',4'-dimethoxyisoflavone, cladrin) demonstrating the highest retention in pig skin. The methoxylated isoflavone SIF-5 showed the greatest permeation into barrier-deficient skin among the compounds tested, with a 6- and 8-fold increase after lipid and protein removal. The cell-based study exhibited the capability of SIFs to restrain the overexpressed IL-6, IL-8, and CXCL1 in stimulated HaCaT. The therapeutic index (TI) predicted the potential candidates of SIF-5 and SIF-6 for topical application to treat psoriatic inflammation. The imiquimod (IMQ)-driven psoriasiform murine model manifested the inhibition of hyperplasia and immune cell infiltration by topically administered SIF-5 and SIF-6. The epidermal thickness of IMQ-treated skin was decreased from 172 to 40 μm by both isoflavones. This effect was comparable with that of betamethasone, the positive control. The topical treatment of SIF-6 significantly reduced cytokine/chemokine upregulation by IMQ. The methoxylated isoflavone with dramatic anti-inflammatory activity is promising for the development of an antipsoriatic agent.

Glibenclamide Nanocrystal-Loaded Bioactive Polymeric Scaffolds for Skin Regeneration: In Vitro Characterization and Preclinical Evaluation

Skin restoration following full-thickness injury poses significant clinical challenges including inflammation and scarring. Medicated scaffolds formulated from natural bioactive polymers present an attractive platform for promoting wound healing. Glibenclamide was formulated in collagen/chitosan composite scaffolds to fulfill this aim. Glibenclamide was forged into nanocrystals with optimized colloidal properties (particle size of 352.2 nm, and polydispersity index of 0.29) using Kolliphor as a stabilizer to allow loading into the hydrophilic polymeric matrix. Scaffolds were prepared by the freeze drying method using different total polymer contents (3-6%) and collagen/chitosan ratios (0.25-2). A total polymer content of 3% at a collagen/chitosan ratio of 2:1 (SCGL3-2) was selected based on the results of in vitro characterization including the swelling index (1095.21), porosity (94.08%), mechanical strength, rate of degradation and in vitro drug release. SCGL3-2 was shown to be hemocompatible based on the results of protein binding, blood clotting and percentage hemolysis assays. In vitro cell culture studies on HSF cells demonstrated the biocompatibility of nanocrystals and SCGL3-2. In vivo studies on a rat model of a full-thickness wound presented rapid closure with enhanced histological and immunohistochemical parameters, revealing the success of the scaffold in reducing inflammation and promoting wound healing without scar formation. Hence, SCGL3-2 could be considered a potential dermal substitute for skin regeneration.

Anti-aging properties of phytoconstituents and phyto-nanoemulsions and their application in managing aging-related diseases

Aging is spontaneous and inevitable process in all living beings. It is a complex natural phenomenon that manifests as a gradual decline of physiological functions and homeostasis. Aging inevitably leads to age-associated injuries, diseases, and eventually death. The research on aging-associated diseases aimed at delaying, preventing or even reversing the aging process are of great significance for healthy aging and also for scientific progress. Numerous plant-derived compounds have anti-aging effects, but their therapeutic potential is limited due to their short shelf-life and low bioavailability. As the novel delivery system, nanoemulsion can effectively improve this defect. Nanoemulsions enhance the delivery of drugs to the target site, maintain the plasma concentration for a longer period, and minimize adverse reaction and side effects. This review describes the importance of nanoemulsions for the delivery of phyto-derived compounds and highlights the importance of nanoemulsions in the treatment of aging-related diseases. It also covers the methods of preparation, fate and safety of nanoemulsions, which will provide valuable information for the development of new strategies in treatment of aging-related diseases.

Nanomaterials in Skin Regeneration and Rejuvenation

Skin is the external part of the human body; thus, it is exposed to outer stimuli leading to injuries and damage, due to being the tissue mostly affected by wounds and aging that compromise its protective function. The recent extension of the average lifespan raises the interest in products capable of counteracting skin related health conditions. However, the skin barrier is not easy to permeate and could be influenced by different factors. In the last decades an innovative pharmacotherapeutic approach has been possible thanks to the advent of nanomedicine. Nanodevices can represent an appropriate formulation to enhance the passive penetration, modulate drug solubility and increase the thermodynamic activity of drugs. Here, we summarize the recent nanotechnological approaches to maintain and replace skin homeostasis, with particular attention to nanomaterials applications on wound healing, regeneration and rejuvenation of skin tissue. The different nanomaterials as nanofibers, hydrogels, nanosuspensions, and nanoparticles are described and in particular we highlight their main chemical features that are useful in drug delivery and tissue regeneration.