Fabrication, Physical Characterizations, and In Vitro, In Vivo Evaluation of Ginger Extract-Loaded Gelatin/Poly(Vinyl Alcohol) Hydrogel Films Against Burn Wound Healing in Animal Model

Matrix metalloproteinase-responsive hydrogels with tunable retention for on-demand therapy of inflammatory bowel disease

Therapeutic options for addressing inflammatory bowel disease (IBD) include the administration of an enema to reduce intestinal inflammation and alleviate associated symptoms. However, uncontrollable retention of enemas in the intestinal tract has posed a long-term challenge for improving their therapeutic efficacy and safety. Herein we have developed a protease-labile hydrogel system as an on-demand enema vehicle with tunable degradation and drug release rates in response to varying matrix metalloproteinase-9 (MMP-9) expression. The system, composed of three tailored hydrogel networks, is crosslinked by poly (ethylene glycol) (PEG) with 2-, 4- and 8-arms through dynamic hydrazone bonds to confer injectability and generate varying network connectivity. The retention time of the hydrogels can be tuned from 12 to 36 h in the intestine due to their different degradation behaviors induced by MMP-9. The drug-releasing rate of the hydrogels can be controlled from 0.0003 mg/h to 0.278 mg/h. In addition, injection of such hydrogels in vivo resulted in significant differences in therapeutic effects including MMP-9 consumption, colon tissue repair, reduced collagen deposition, and decreased macrophage cells, for treating a mouse model of acute colitis. Among them, GP-8/5-ASA exhibits the best performance. This study validates the effectiveness of the tailored design of hydrogel architecture in response to pathological microenvironment cues, representing a promising strategy for on-demand therapy of IBD. STATEMENT OF SIGNIFICANCE: The uncontrollable retention of enemas at the delivery site poses a long-term challenge for improving therapeutic efficacy in IBD patients. MMP-9 is highly expressed in IBD and correlates with disease severity. Therefore, an MMP-9-responsive GP hydrogel system was developed as an enema by linking multi-armed PEG and gelatin through hydrazone bonds. This forms a dynamic hydrogel characterized by in situ gelation, injectability, enhanced bio-adhesion, biocompatibility, controlled retention time, and regulated drug release. GP hydrogels encapsulating 5-ASA significantly improved the intestinal phenotype of acute IBD and demonstrated notable therapeutic differences with increasing PEG arms. This method represents a promising on-demand IBD therapy strategy and provides insights into treating diseases of varying severities using endogenous stimulus-responsive drug delivery systems.

Topical amlodipine-loaded solid lipid nanoparticles for enhanced burn wound healing: A repurposed approach

Burn wounds are a complicated process with ongoing psychological and physical issues for the affected individuals. Wound healing consists of multifactorial molecular mechanisms and interactions involving; inflammation, proliferation, angiogenesis, and matrix remodeling. Amlodipine (ADB), widely used in cardiovascular disorders, demonstrated antioxidant and anti-inflammatory effects in some non-cardiovascular studies. It was reported that amlodipine is capable of promoting the healing process by regulation of collagen production, extracellular matrix, re-epithelialization and wound healing through its vasodilation and angiogenic activity. The objective of the current study is to appraise the wound healing capacity of amlodipine-loaded SLN (ADB-SLN) integrated into a hydrogel. The in-vitro characterization revealed that the optimized formulation was nanometric (190.4 ± 1.6 nm) with sufficiently high entrapment efficiency (88 % ± 1.4) and sustained ADB release (85.45 ± 4.45 % after 12 h). Furthermore, in-vivo evaluation was conducted on second-degree burns induced in male Sprague-Dawley rats. ADB-SLN gel revealed a high wound contraction rate and a significant improvement in skin regeneration and inflammatory biomarkers levels, confirming its efficiency in enhancing wound healing compared to other tested and commercial formulations. To conclude, the present findings proved that ADB-SLN integrated hydrogel offers a promising novel therapy for burn wound healing with a maximum therapeutic value.

Development of raft-forming liquid formulations loaded with ginger extract-solid dispersion for treatment of gastric ulceration

Raft-forming liquid formulations incorporating ginger extract solid dispersion (GE-SD) were developed to achieve prolonged delivery of 6-gingerol in the stomach and thus increase the effectiveness of gastric ulcer treatment. The solubility of 6-gingerol in 0.1 N HCl (pH 1.2) was maximized (15 mg/mL) by combining ginger extract with PVP K30 at 1:3 w/w ratio to produce a solid dispersion. The nature of GE-SD was confirmed by PXRD and FT-IR analysis. PXRD pattern showed miscibility of GE and PVP K30 in amorphous solid dispersion and the FT-IR spectra confirmed the formation of hydrogen bond between GE and PVP K30. GE-SD-loaded raft-forming liquids were prepared using sodium alginate as a gel former and HPMC as a release-controlling agent. The formulations exhibited rapid floating behavior in 0.1 N HCl (<30 s) and remained afloat on the surface over 8 h. The formed raft structures provided sufficient strength (>7.5 g) and allowed sustained release of more than 70 % of the 6-gingerol content over 8 h in 0.1 N HCl. Raft-forming formulations incorporating ginger extract demonstrated anti-inflammatory activity by inhibiting nitric oxide production in LPS-stimulated RAW 264.7 macrophage cells (IC50 = 5.13 ± 0.07 μg/mL). Exposure to the formulations also had a significant cytotoxic effect on AGS human gastric adenocarcinoma cells with an IC50 of 17.45 ± 0.29 μg/mL. In addition, the raft-forming formulations enhanced the migratory behavior of L929 mouse fibroblasts in the scratch wound model. Taken together, these findings reveal the benefits of gastro-retentive, GE-SD-loaded raft-forming liquid formulations for improving the treatment of gastric ulcers.

A Novel Food Bore Protein Hydrogel with Silver Ions for Promoting Burn Wound Healing

Hydrogels have emerged as a promising option for treating local scald wounds due to their unique physical and chemical properties. This study aims to evaluate the efficacy of ovalbumin/gelatin composite hydrogels in repairing deep II-degree scald wounds using a mouse dorsal skin model. Trauma tissues collected at various time points are analyzed for total protein content, hydroxyproline content, histological features, and expression of relevant markers. The results reveal that the hydrogel accelerates the healing process of scalded wounds, which is 17.27% higher than the control group. The hydrogel treatment also effectively prevents wound enlargement and redness of the edges caused by infection during the initial stage of scalding. The total protein and hydroxyproline content of the treated wounds are significantly elevated. Additionally, the hydrogel up-regulates the expression of VEGF (a crucial angiogenic factor) and down-regulates CD68 (a macrophage marker). In summary, this study provides valuable insights into the potential of multifunctional protein-based hydrogels in wound healing.

Chitosan-Aloe Vera Composition Loaded with Zinc Oxide Nanoparticles for Wound Healing: In Vitro and In Vivo Evaluations

Global concerns due to the negative impacts of untreatable wounds, as well as the growing population of these patients, emphasize the critical need for advancements in the wound healing materials and techniques. Nanotechnology offers encouraging avenues for improving wound healing process. In this context, nanoparticles (NPs) and certain natural materials, including chitosan (CS) and aloe vera (AV), have demonstrated the potential to promote healing effects. The objective of this investigation is to assess the effect of novel fabricated nanocomposite gel containing CS, AV, and zinc oxide NPs (ZnO NPs) on the wound healing process. The ZnO NPs were synthesized and characterized by X-ray diffraction and electron microscopy. Then, CS/AV gel with different ratios was prepared and loaded with ZnO NPs. The obtained formulations were characterized in vitro based on an antimicrobial study, and the best formulations were used for the animal study to assess their wound healing effects in 21 days. The ZnO NPs were produced with an average 33 nm particle size and exhibited rod shape morphology. Prepared gels were homogenous with good spreadability, and CS/AV/ZnO NPs formulations showed higher antimicrobial effects against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. The wound healing findings showed significant wound area reduction in the CS/AV/ZnO NPs group compared to negative control at day 21. Histopathological assessment revealed the advantageous impact of this formulation across various stages of the wound healing process, including collagen deposition (CS/AV/ZnO NPs (2 : 1), 76.6 ± 3.3 compared to negative control, 46.2 ± 3.7) and epitheliogenesis (CS/AV/ZnO NPs (2 : 1), 3 ± 0.9 compared to negative control, 0.8 ± 0.8). CS/AV gel-loaded ZnO NPs showed significant effectiveness in wound healing and would be suggested as a promising formulation in the wound healing process. Further assessments are warranted to ensure the robustness of our findings.

Zingiber officinale and thymus vulgaris extracts co-loaded polyvinyl alcohol and chitosan electrospun nanofibers for tackling infection and wound healing promotion

Infections are severe complications associated with chronic wounds and tardy healing that should be timely treated to achieve rapid and proper tissue repair. To hinder such difficulties, a nanofibrous mat composed of polyvinyl alcohol and chitosan (PVA/CS) was developed by electrospinning method, containing thyme (Thymus vulgaris) and ginger (Zingiber officinale) extracts. The mat containing 10 wt% of the extracts (at the ratio of 50:50) exposed the nanofibers (NFs) with the nanoscale diameter (average 382 ± 60 nm), smooth surface, and defect-free morphology. Likewise, the relevant analyses of the loaded mat displayed high wettability, porosity, and liquid absorption capacity without any adverse interaction. The obtained mat also provided a high antioxidant activity, and its release profile was continuous and sustained for nearly 72 h. Besides, it inhibited the growth of both Gram-positive S. aureus and Gram-negative E. coli strains. Furthermore, the proposed mat significantly accelerated cutaneous wound healing in bacterial-infected rats by preventing bacteria growth at the wound site. At last, histopathology analysis confirmed the ample regeneration of skin structures, forming collagen fibers and appendages. Overall, the proposed mat containing ginger-thyme extracts provides multiple therapeutic capabilities with promising solutions for inhibiting wound infection and accelerating the healing process.

Synthesis and characterization of Hyaluronic Acid (HA) modified polymeric composite for effective treatment of wound healing by transdermal drug delivery system (TDDS)

The present study aimed to fabricate a novel polymeric spongy composite to enhance skin regeneration composed of Nystatin (antifungal agent) and Silver Nanoparticles (AgNps). Different formulations (F1-F8) were developed & characterized by using various analytical techniques. AgNps synthesized by chemical reduction method showed spherical morphology 2 µm in size showed by SEM and XRD. A fine porous structure of gel embedded with AgNps having an amorphous structure with 10 % crystallinity due to AgNps was found. IR spectra revealed no chemical interaction between polymers and Nystatin. An increase in thermal stability of formulation was observed till 700 ℃ analyzed by Differential Scanning Calorimetry. Cytotoxic analysis on L929 mouse skin fibroblast cells showed a decrease in cell viability as Ag concentration increased (inactivating Fibroblast and keratinocytes) while 10 mg composition was found safest concentration (94%). Optimized formulation (F2) presented in-vitro drug release up to 90.59% ± 0.76 at pH 7.4, swelling studies (87.5% ± 0.57), water retention (26.60 ± 0.34), pH (5.31 ± 0.03). In the animal burn model, the group that received CHG/Ag/Nystatin healed the wound significantly (p < 0.05). These results suggested that optimized carrier can be used for other anti-fungal drugs facilitating the early healing of the wound.

Bergenia stracheyi extract-based hybrid hydrogels of biocompatible polymers with good adhesive, stretching, swelling, self-healing, antibacterial, and antioxidant properties

An ultra-stretchable, quickly self-healable, adhesive hydrogel with efficient anti-oxidant and anti-bacterial activities makes it potential wound dressing material, particularly in healing skin wounds. However, it is highly challenging to prepare such hydrogels with a facile and efficient material design. Given this, we opine the synthesis of medicinal plant Bergenia stracheyi extract-loaded hybrid hydrogels of biocompatible and biodegradable polymers like Gelatin, Hydroxypropyl cellulose, and Polyethylene glycol with acrylic acid via in situ free radical polymerization reaction. The selected plant extract is rich in phenols, flavonoids, and tannins and found to have important therapeutic benefits such as anti-ulcer, anti-Human Immunodeficiency Virus, anti-inflammatory, and burn wound healing effects. The polyphenolic compounds in the plant extract interacted strongly via hydrogen bonding with -OH, -NH₂, -COOH, and C-O-C groups of the macromolecules. The synthesized hydrogels were characterized by fourier transform infrared spectroscopy and rheology. The as-prepared hydrogels demonstrate ideal tissue adhesion, excellent stretchability, good mechanical strength, broad-band anti-bacterial capability, and efficient anti-oxidant properties, in addition to quick self-healing and moderate swelling properties. Thus, the aforementioned properties attract the potential use of these materials in the biomedical field.

Garlic and ginger essential oil-based neomycin nano-emulsions as effective and accelerated treatment for skin wounds' healing and inflammation: In-vivo and in-vitro studies

Skin, largest organ of human, is directly exposed to environment and hence is prone to high rates of injuries and microbial infections. Over the passage of time these microbes have developed resistance to antibiotics making them ineffective especially in lower doses and hence, higher dosages or new drugs are required. The current study deals with designing of nano-emulsion (NE) formulations composed of garlic and ginger oils (0.1 %) with neomycin sulphate used in different ratios (0.001, 0.01 and 0.1 %) and combinations. The resulting NEs were characterized for droplet size (145-304 nm), zetapotential (-3.0-0.9 mV), refractive index (1.331-1.344), viscosity (1.10-1.23cP), transmittance (96-99 %), FT-IR and HPLC and found stable over a period of three months. All NEs were also found effective against both gram positive and negative bacterial strains i.e., B. spizizenii, S. aureus, E. coli and S. enterica as compared to pure neomycin sulphate (NS) used as control with highest activity recorded for NE-2 and NE-4 against all strains showing zone of inhibition in range of 22-30 mm and 21-19 mm, respectively. NEs were also tested using rabbit skin excision wound model which potentiates that all the NEs resulted in early recovery with 86-100 % wound healing achieved in 9 days as compared to NS ointment (71 %). The studies confirmed that essential oils when used in combination with traditional drug can lead to much higher efficacies as compared to pure drugs.

Ginger Loaded Polyethylene Oxide Electrospun Nanomembrane: Rheological and Antimicrobial Attributes

Synthetic antibiotics have captured the market in recent years, but the side effects of these products are life-threatening. In recent times, researchers have focused their research on natural-based products such as natural herbal oils, which are eco-friendly, biocompatible, biodegradable, and antibacterial. In this study, polyethylene oxide (PEO) and aqueous ginger extract (GE) were electrospun to produce novel antibacterial nanomembrane sheets as a function of PEO and GE concentrations. A GE average particle size of 91.16 nm was achieved with an extensive filtration process, inferring their incorporation in the PEO nanofibres. The presence of the GE was confirmed by Fourier transform infrared spectroscopy (FTIR) through peaks of phenol and aromatic groups. The viscoelastic properties of PEO/GE solutions were analysed in terms of PEO and GE concentrations. Increasing PEO and GE concentrations increased the solution's viscosity. The dynamic viscosity of 3% was not changed with increasing shear rate, indicating Newtonian fluid behaviour. The dynamic viscosity of 4 and 5 wt% PEO/GE solutions containing 10% GE increased exponentially compared to 3 wt%. In addition, the shear thinning behaviour was observed over a frequency range of 0.05 to 100 rad/s. Scanning Electron Microscopy (SEM) analysis also specified an increase in the nanofibre's diameter with increasing PEO concentration, while SEM images displayed smooth morphology with beadless nanofibres at different PEO/GE concentrations. In addition, PEO/GE nanomembranes inhibited the growth of Staphylococcus aureus, as presented by qualitative antibacterial results. The extent of PEO/GE nanomembrane's antibacterial activity was further investigated by the agar dilution method, which inhibited the 98.79% Staphylococcus aureus population at 30% GE concentration.

Chitosan-based films with cannabis oil as a base material for wound dressing application

This study focuses on obtaining and characterizing novel chitosan-based biomaterials containing cannabis oil to potentially promote wound healing. The primary active substance in cannabis oil is the non-psychoactive cannabidiol, which has many beneficial properties. In this study, three chitosan-based films containing different concentrations of cannabis oil were prepared. As the amount of oil increased, the obtained biomaterials became rougher as tested by atomic force microscopy. Such rough surfaces promote protein adsorption, confirmed by experiments assessing the interaction between human albumin with the obtained materials. Increased oil concentration also improved the films' mechanical parameters, swelling capacity, and hydrophilic properties, which were checked by the wetting angle measurement. On the other hand, higher oil content resulted in decreased water vapour permeability, which is essential in wound dressing. Furthermore, the prepared films were subjected to an acute toxicity test using a Microtox. Significantly, the film's increased cannabis oil content enhanced the antimicrobial effect against A. fischeri for films in direct contact with bacteria. More importantly, cell culture studies revealed that the obtained materials are biocompatible and, therefore, they might be potential candidates for application in wound dressing materials.

Polymer-Based Hydrogels Enriched with Essential Oils: A Promising Approach for the Treatment of Infected Wounds

Among the factors that delay the wound healing process in chronic wounds, bacterial infections are a common cause of acute wounds becoming chronic. Various therapeutic agents, such as antibiotics, metallic nanoparticles, and essential oils have been employed to treat infected wounds and also prevent the wounds from bacterial invasion. Essential oils are promising therapeutic agents with excellent wound healing, anti-inflammatory and antimicrobial activities, and good soothing effects. Some essential oils become chemically unstable when exposed to light, heat, oxygen, and moisture. The stability and biological activity of essential oil can be preserved via loading into hydrogels. The polymer-based hydrogels loaded with bioactive agents are regarded as ideal wound dressings with unique features, such as controlled and sustained drug release mechanisms, good antibacterial activity, non-toxicity, excellent cytocompatibility, good porosity, moderate water vapour transmission rate, etc. This review addresses the pre-clinical outcomes of hydrogels loaded with essential oils in the treatment of infected wounds.

Effectiveness of Copper Nanoparticles in Wound Healing Process Using In Vivo and In Vitro Studies: A Systematic Review

Chronic wounds are defined as wounds that do not heal in an orderly and timely manner through the various stages of the healing process. Copper nanoparticles are essential in dressings for wound healing because they promote angiogenesis and skin regeneration, which hasten the healing process. This systematic investigation sought to explain how copper nanoparticles affect chronic wound healing in vivo and in vitro. We realized a systematic review of original articles studying the effectiveness of copper nanoparticles in the healing process of chronic wounds. The protocol was registered in the PROSPERO database. Several databases were searched between 2012 and January 2022 for English-language papers using MeSH terms and text related to chronic wounds, copper nanoparticles, and wound healing. Quality was evaluated using National Institute for Health and Care Excellence methodology and PRISMA guidelines. We looked at a total of 12 primary studies. Quantitative data were gathered and presented in all studies. Our results suggest that copper nanoparticles could have an excellent healing property, facilitating the liberation of growth factors that help the anti-inflammatory process of the wound and significantly improving antibacterial and antioxidant activities. In addition, copper presents a higher biocompatibility than other metallic ions, promoting regeneration and increasing skin quality.

Synthesis and In Vitro/Ex Vivo Characterizations of Ceftriazone-Loaded Sodium Alginate/Poly(Vinyl Alcohol) Clay Reinforced Nanocomposites: Possible Applications in Wound Healing

(1) Background: Nanocomposite films are widely applied in the pharmaceutical industry (e.g., nanodrug delivery systems—NDDS). Indeed, these nanomaterials can be produced at a large industrial scale and display valuable properties (e.g., antibacterial, renewability, biodegradability, bioavailability, safety, tissue-specific targeting, and biocompatibility), which can enhance the activity of conventional marketed drugs. (2) Aim: To fabricate and investigate the in vitro properties of the antibiotic ceftriaxone sodium (CTX) once encapsulated into sodium alginate (SA)/poly(vinyl alcohol)PVA-clay reinforced nanocomposite films. (3) Methods: Different ratios of the polymers (i.e., SA, PVA) and CTX drug were used for the synthesis of nanocomposite films by solvent casting technique. Montmorillonite (MMT), modified organically, was added as a nanofiller to increase their thermal and mechanical strength. The prepared samples were physically characterized by thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electronic microscopy (SEM), and energy-dispersive X-ray analysis (EDX). The physicochemical behavior (i.e., swelling, erosion, dissolution/drug release behavior and rat skin permeation) was also assessed. Comparisons were made with the currently marketed free CTX dosage form. (4) Results: TGA of the nanoformulation showed increased thermostability. XRD revealed its semi-crystalline nature. SEM depicted a homogeneous drug-loaded SA/PVA nanocomposite with an average size ranging between 300 and 500 nm. EDX confirmed the elemental composition and uniform distribution of mixing components. The water entrapment efficiency study showed that the highest swelling and erosion ratio is encountered with the nanoformulations S100(3) and S100D15(3). Ex vivo permeation revealed a bi-step discharge mode with an early burst liberation chased by continued drug discharge of devised nanoparticles (NPs). The dissolution studies of the drug-loaded polymer nanocomposites elicited sustained pH-dependent drug release. The cumulative drug release was the highest (90.93%) with S100D15(3). (5) Conclusion: S100D15(3) was the finest formulation. To the best of our knowledge, we also pioneered the use of solvent casting for the preparation of such nanoformulations. Polymers and reinforcing agent, concentrations and pH were rate-deterring features for the preparation of the optimized formulation. Thus, CTX-loaded SA/PVA-MMT reinforced nanocomposite appeared as a promising nanodrug delivery system (NDDS) based on its in vitro physicochemical properties.

An In Vitro and In Vivo Study of the Efficacy and Toxicity of Plant-Extract-Derived Silver Nanoparticles

Silver nanoparticles (AgNPs) display unique plasmonic and antimicrobial properties, enabling them to be helpful in various industrial and consumer products. However, previous studies showed that the commercially acquired silver nanoparticles exhibit toxicity even in small doses. Hence, it was imperative to determine suitable synthesis techniques that are the most economical and least toxic to the environment and biological entities. Silver nanoparticles were synthesized using plant extracts and their physico-chemical properties were studied. A time-dependent in vitro study using HEK-293 cells and a dose-dependent in vivo study using a Drosophila model helped us to determine the correct synthesis routes. Through biological analyses, we found that silver nanoparticles’ cytotoxicity and wound-healing capacity depended on size, shape, and colloidal stability. Interestingly, we observed that out of all the synthesized AgNPs, the ones derived from the turmeric extract displayed excellent wound-healing capacity in the in vitro study. Furthermore, the same NPs exhibited the least toxic effects in an in vivo study of ingestion of these NPs enriched food in Drosophila, which showed no climbing disability in flies, even at a very high dose (250 mg/L) for 10 days. We propose that stabilizing agents played a superior role in establishing the bio-interaction of nanoparticles. Our study reported here verified that turmeric-extract-derived AgNPs displayed biocompatibility while exhibiting the least cytotoxicity.

Perspective on the application of medicinal plants and natural products in wound healing: A mechanistic review

Wound is defined as any injury to the body such as damage to the epidermis of the skin and disturbance to its normal anatomy and function. Since ancient times, the importance of wound healing has been recognized, and many efforts have been made to develop novel wound dressings made of the best material for rapid and effective wound healing. Medicinal plants play a great role in the wound healing process. In recent decades, many studies have focused on the development of novel wound dressings that incorporate medicinal plant extracts or their purified active compounds, which are potential alternatives to conventional wound dressings. Several studies have also investigated the mechanism of action of various herbal medicines in wound healing process. This paper attempts to highlight and review the mechanistic perspective of wound healing mediated by plant-based natural products. The findings showed that herbal medicines act through multiple mechanisms and are involved in various stages of wound healing. Some herbal medicines increase the expression of vascular endothelial growth factor (VEGF) and transforming growth factor-β (TGF-β) which play important role in stimulation of re-epithelialization, angiogenesis, formation of granulation tissue, and collagen fiber deposition. Some other wound dressing containing herbal medicines act as inhibitor of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and inducible nitric oxide synthase (iNOS) protein expression thereby inducing antioxidant and anti-inflammatory properties in various phases of the wound healing process. Besides the growing public interest in traditional and alternative medicine, the use of herbal medicine and natural products for wound healing has many advantages over conventional medicines, including greater effectiveness due to diverse mechanisms of action, antibacterial activity, and safety in long-term wound dressing usage.

RETRACTED: Preparation, characterizations and evaluation of antifungal activity of eugenol-linalool emulgel against anthrophilic dermatophytic trichophyton rubrum

This article has been retracted, and the online PDF has been watermarked “RETRACTION”. The retraction notice is available at https://doi.org/10.3233/MGC-219901.

Differentiating Co-Delivery of Bisphosphonate and Simvastatin by Self-Healing Hyaluronan Hydrogel Formed by Orthogonal "Clicks": An In-Vitro Assessment

Due to its unique properties resembling living tissues, hydrogels are attractive carriers for the localized and targeted delivery of various drugs. Drug release kinetics from hydrogels are commonly controlled by network properties and the drug-network interactions. However, and simultaneously, the programmable delivery of multiple drugs with opposing properties (hydrophilicity, molecular weight, etc.) from hydrogels with determined network properties is still challenging. Herein, we describe the preparation of injectable self-healing hyaluronic acid (HA) hydrogels that release hydrophobic simvastatin and hydrophilic aminobisphosphonate (BP) drugs independently in response to acidic and thiol-containing microenvironments, respectively. We apply a prodrug strategy to BP by conjugating it to HA via a self-immolative disulfide linker that is stable in the blood plasma and is cleavable in the cytoplasm. Moreover, we utilize HA-linked BP ligands to reversibly bind Ca²⁺ ions and form coordination hydrogels. Hydrazone coupling of hydrophobic ligands to HA permits the encapsulation of simvastatin molecules in the resulting amphiphilic HA derivative and the subsequent acid-triggered release of the drug. The conjugation of BP and hydrophobic ligands to HA enables preparation of both bulk self-healing hydrogels and nanogels. Moreover, the developed hydrogel system is shown to be multi-responsive by applying orthogonally cleavable linkers. The presented hydrogel is a potential candidate for the combination treatment of osteoporosis and bone cancers as well as for bone tissue regeneration since it can deliver bone anabolic and anti-catabolic agents in response to bone diseases microenvironments.

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.