Development and in vitro/in vivo evaluation of HPMC/chitosan gel containing simvastatin loaded self-assembled nanomicelles as a potent wound healing agent

In Vitro and In Vivo Evaluation of Chitosan/HPMC/Insulin Hydrogel for Wound Healing Applications

Treatment of chronic wounds is challenging, and the development of different formulations based on insulin has shown efficacy due to their ability to regulate oxidative stress and inflammatory reactions. The formulation of insulin with polysaccharides in biohybrid hydrogel systems has the advantage of synergistically combining the bioactivity of the protein with the biocompatibility and hydrogel properties of polysaccharides. In this study, a hydrogel formulation containing insulin, chitosan, and hydroxypropyl methyl cellulose (Chi/HPMC/Ins) was prepared and characterized by FTIR, thermogravimetric, and gel point analyses. The in vitro cell viability and cell migration potential of the Chi/HPMC/Ins hydrogel were evaluated in human keratinocyte cells (HaCat) by MTT and wound scratch assay. The hydrogel was applied to excisional full-thickness wounds in diabetic mice for twenty days for in vivo studies. Cell viability studies indicated no cytotoxicity of the Chi/HPMC/Ins hydrogel. Moreover, the Chi/HPMC/Ins hydrogel promoted faster gap closure in the scratch assay. In vivo, the wounds treated with the Chi/HPMC/Ins hydrogel resulted in faster wound closure, formation of a more organized granulation tissue, and hair follicle regeneration. These results suggest that Chi/HPMC/Ins hydrogels might promote wound healing in vitro and in vivo and could be a new potential dressing for wound healing.

Simvastatin nanocrystals-based dissolving microneedles for wound healing

Currently, one of the main problems encountered in wound healing therapy is related to inefficient drug delivery. However, dissolving microneedles (DMNs) can be administered percutaneously to effectively deliver a drug to a deep wound area. Simvastatin (SIM) can promote wound healing, albeit its insolubility in water limits its application. Here, we designed a DMNs (SIM-NC@DMNs) drug delivery system loaded with SIM nanocrystals (SIM-NC) and evaluated its efficacy in wound healing. Based on our observations, the dissolution performance of insoluble SIM is significantly improved after the preparation of SIM-NC. For example, the saturation solubility of SIM-NC in deionized water and PBS increased by 150.57 times and 320.14 times, respectively. After the SIM-NC@DMNs are deeply inserted into the wound, the needle portion, which is composed of hyaluronic acid (HA), dissolves rapidly, and the SIM-NC loaded on the needle portion is efficiently released into the deep wound area for optimal therapeutic efficacy. The combination of NC and DMNs makes this system further effective for wound healing. Our cumulative work suggests that the newly developed SIM-NC@DMNs possess great potential in accelerating wound healing. By day 12 after treatment, the residual wound area in the Control group was 21.34 %, while the residual wound area in the SIM-NC@DMNs group was only 2.36 %. This result as well as provides certain evidence of its efficacy for wound healing therapy. The SIM-NC@DMNs drug delivery system may become an efficient treatment modality that promotes wound healing, with a promising potential in the field of wound healing research.

Simvastatin-Loaded Nanostructured Lipid Carriers as Topical Drug Delivery System for Wound Healing Purposes: Preparation, Characterization, and In Vivo Histopathological Studies

Purpose

Simvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, is a commonly used drug to reduce total cholesterol and low-density lipoprotein (LDL) levels. Furthermore, several mechanisms showed the wound-healing potential of statins, especially simvastatin. Simvastatin is a lipophilic drug, therefore, it has low water solubility with limited skin permeability potential. In this regard, nanostructured lipid carriers (NLCs) were recruited as novel topical drug delivery systems to enhance skin adhesion and film formation, maintain skin integrity, sustain the release of simvastatin, and prolong simvastatin skin deposition to help pressure ulcers healing and regeneration.

Methods

NLCs were fabricated using the solvent diffusion evaporation technique. Drug loading, in vitro drug release, and morphological assessment on the optimized formulation were considered. Furthermore, in vivo effect of simvastatin-loaded NLCs gel on pressure ulcer healing was assessed using a rat skin model. Histopathological assessments were compared with conventional simvastatin gel and drug-free NLCs gel.

Results

Simvastatin-loaded NLC with an average diameter of 100 nm was considered as the optimum formulation. According to the results entrapment efficiency of simvastatin within the NLCs was about 99.4%. Drug release studies revealed sustained drug release from NLCs in which about 87% of the drug was slowly released during 48 hours. Animal study results confirmed that simvastatin-loaded NLCs gel has better efficacy on pressure ulcers and could significantly reduce inflammation, and promote skin regeneration compared to both drug-free NLCs and conventional simvastatin gels.

Conclusion

Simvastatin-loaded NLCs with an average particle size of 100 nm would be a promising novel topical drug delivery system with sustained drug release potential for pressure ulcer treatment.

Formulation and evaluation of simvastatin cubosomal nanoparticles for assessing its wound healing effect

Wound healing is one of the most challenging medical circumstances for patients. Pathogens can infect wounds, resulting in tissue damage, inflammation, and disruption of the healing process. Simvastatin was investigated recently, as a wound healing agent that may supersede the present therapies for wounds. Our goal in this paper is to focus on formulation of simvastatin cubosomes for topical delivery, as a potential approach to improve simvastatin skin permeation. By this technique its wound healing effect could be improved. Cubosomes were prepared using the top-down method and the prepared cubosomes were characterized by several techniques. The most optimal simvastatin cubosomal formulation was then included in a cubogel dosage form using different gelling agents. The results showed that the average particle size of the prepared cubosomes was 113.90 ± 0.58 nm, the entrapment efficiency was 93.95 ± 0.49% and a sustained simvastatin release was achieved. The optimized formula of simvastatin cubogel displayed pseudoplastic rheological behavior. This same formula achieved enhancement in drug permeation through excised rat skin compared to free simvastatin hydrogel with flux values of 46.18 ± 2.12 mcg cm-2 h-1 and 25.92 ± 3.45 mcg cm-2 h-1 respectively. Based on the in-vivo rat studies results, this study proved a promising potential of simvastatin cubosomes as wound healing remedy.

Integration of terpesomes loaded Levocetrizine dihydrochloride gel as a repurposed cure for Methicillin-Resistant Staphylococcus aureus (MRSA)-Induced skin infection; D-optimal optimization, ex-vivo, in-silico, and in-vivo studies

The intention of this work is to assess the repurposed antimicrobial impact of Levocetirizine dihydrochloride (LVC), which is a well-known antihistaminic drug, in addition, to augment the antimicrobial effect by using terpene-enriched vesicles (TPs). To investigate how various parameters affect TPs aspects, TPs were made employing the ethanol-injection-method and optimized d-optimal design. The TPs were characterized based on their entrapment efficiency percentage (EE%), particle size (PS), polydispersity index (PDI), and zeta potential (ZP). The optimum TP was submitted to more examinations. The optimum TP (TP12) showed a spherical vesicle having an EE% of 66.39 ± 0.12%, PS of 243.3 ± 4.60 nm, PDI of 0.458 ± 0.003, and ZP of 24.2 ± 0.55 mV. The in-vitro release study results demonstrated that LVC is sustainedly liberated from the optimum TP compared to LVC-solution. The ex-vivo assessment showed that LVC was released in a more sustained manner from TPs-gel related to LVC solution, optimum TP, and LVC gel. Ex-vivo visualization by confocal laser scanning microscopy showed good deposition of the fluorescein-labeled TP. Further, the in-vitro anti-bacterial effect and biofilm inhibition and detachment assessment confirmed the potency of LVC against Methicillin-resistant-Staphylococcus-aureus (MRSA). The in-silico study demonstrated that the LVC has excellent stability with other ingredients combined with it in the TPs, further, it proved that LVC is a potential candidate for treating MRSA. In-vivo assessments revealed a good antimicrobial effect toward MRSA infection. Moreover, the histopathological evaluation confirmed the safety of using TPs-gel topically. In conclusion, MRSA-related skin infections may be treated using the LVC loaded TPs-gel as a promising system.

Overexpression of TRPM7 contributes promotesto the therapeutic effect of curcumin in treatmentprocess of wound healing through STAT3/SMAD3 signaling pathway in human fibroblasts

OBJECTIVE

Curcumin, a natural extract from the rhizomes of Curcuma longa, is also known as a curcuminoid. Curcumin has been studied as a therapeutic drug for wound healing because of its anti-inflammatory, anti-oxidant, and anti-bacterial activities. However, the detailed mechanism of curcumin in wound healing is not clear. It is well-known that the skin is the largest organ in humans and prevents tissues from damage, including infection, radiation, and mechanical damage. Wound healing of the skin is a complex physiological regulation process requiring various cell types and cytokines; hence, wound healing, including surgery and care, incurs a huge expenditure each year. Transient receptor potential cation channel subfamily M member 7 (TRPM7) regulates multiple physiological and pharmacological processes through its channel and kinase activities. In addition, TRPM7 regulates cell adhesion, migration, and anti-oxidative activity, thereby playing a regulatory role in the wound healing process. This study aimed to explore the function of curcumin in the wound healing process.

METHODS

We first established TRPM7 overexpression and knockdown models in fibroblasts using lentivirus. CCK-8 and wound healing assays were used to clarify whether overexpression of TRPM7 promoted proliferation and migration in fibroblasts. Expression of target genes and proteins was detected using qPCR and western blotting. Concentrations of migration-related cytokines were measured using ELISA.

RESULTS

Proliferation and migration of fibroblasts increased after curcumin treatment and was further enhanced after overexpression of TRPM7. In addition, expression of proliferation-related genes and proteins was elevated after TRPM7 overexpression. Further, the secretion of migration-related cytokines was elevated after TRPM7 overexpression.

CONCLUSION

Curcumin treatment promoted proliferation and migration of fibroblasts, and these effects were mediated by the signal transducer and activator of transcription 3 (STAT3)/SMAD family member 3/hypoxia-inducible factor 1 subunit alpha signaling pathway. Thus, we conclude that overexpression of TRPM7 might contribute to wound healing.

Topical delivery of pluronic F127/TPGS mixed micelles-based hydrogel loaded with glycyrrhizic acid for atopic dermatitis treatment

OBJECTIVE

The purpose of this study was to develop pluronic F127/D-a-tocopheryl polyethylene glycol 1000 succinate mixed micelles-based hydrogel (MMs-gel) for topical delivery of GL to improve its skin permeability and atopic dermatitis (AD) treatment.

SIGNIFICANCE

GL loaded MMs-gel (GL-MMs-gel) could be potentially used as a promising nanocarrier for the treatment of AD.

METHODS

GL-MMs were prepared by thin film hydration method and then loaded into carbopol gel. The formulation of GL-MMs-gel was optimized by full factorial design and systematically characterized for drug content, pH, spreadability, in vitro drug release and percutaneous permeation, etc. The therapeutic effect of GL-MMs-gel was also investigated in AD-like skin lesion model in BALB/c mice and compared with GL solution-based gel (GL-sol-gel).

RESULTS

Spherical GL-MMs with particle size of ∼30 nm were successfully incorporated into carbopol gel to form GL-MMs-gel with drug content of (98.80 ± 1.30) %, pH of 6.0 ± 0.08, and spreadability of (7.1 ± 0.2) cm. In vitro drug release profile of GL-MMs-gel exhibited a sustained-release behavior. The permeation flux for GL-MMs-gel (5.15 ± 0.33 µg/cm²/h) was significantly higher than that of GL-sol-gel (3.08 ± 0.34 µg/cm²/h) and GL-MMs-gel increased the accumulative amounts of GL in rats' skin 8.41 times than GL-sol-gel. The GL-MMs-gel was more effective than GL-sol-gel in suppressions of various AD symptoms including skin lesions, edema, high IgE levels, epidermal hyperplasia, and mast cell infiltration.

CONCLUSION

All results revealed that MMs-gel could be a promising carrier for topical delivery of GL for the treatment of AD.

An Overview of Cellulose Derivatives-Based Dressings for Wound-Healing Management

Presently, notwithstanding the progress regarding wound-healing management, the treatment of the majority of skin lesions still represents a serious challenge for biomedical and pharmaceutical industries. Thus, the attention of the researchers has turned to the development of novel materials based on cellulose derivatives. Cellulose derivatives are semi-synthetic biopolymers, which exhibit high solubility in water and represent an advantageous alternative to water-insoluble cellulose. These biopolymers possess excellent properties, such as biocompatibility, biodegradability, sustainability, non-toxicity, non-immunogenicity, thermo-gelling behavior, mechanical strength, abundance, low costs, antibacterial effect, and high hydrophilicity. They have an efficient ability to absorb and retain a large quantity of wound exudates in the interstitial sites of their networks and can maintain optimal local moisture. Cellulose derivatives also represent a proper scaffold to incorporate various bioactive agents with beneficial therapeutic effects on skin tissue restoration. Due to these suitable and versatile characteristics, cellulose derivatives are attractive and captivating materials for wound-healing applications. This review presents an extensive overview of recent research regarding promising cellulose derivatives-based materials for the development of multiple biomedical and pharmaceutical applications, such as wound dressings, drug delivery devices, and tissue engineering.

Fabrication and evaluation of hesperidin loaded polyacrylonitrile/polyethylene oxide nanofibers for wound dressing application

In this study, hesperidin (HPN) loaded polyacrylonitrile (PAN)/polyethylene oxide (PEO) electrospun nanofibers were prepared for use as wound dressing. Accordingly, HPN loaded hybrid nanofibers were generated via electrospinning. A full factorial design was then applied to evaluate the influence of formulation variables including PEO amount, HPN amount and total polymer amount on the nanofiber features. Fabricated membranes were evaluated in terms of morphology, diameter, entrapment efficiency (EE) %, drug loading (DL) %, release efficiency (RE) %, swelling % and mechanical properties. Analysis of the obtained data showed that the amount of PEO was the most effective factor impacting the swelling and release percentage; by raising the amount of PEO from 20% to 40%, the swelling % and release rate were considerably increased. The optimized nanofibers were found to be non-beaded, smooth and cylindrical with fiber diameter of 126.14 ± 23.96 nm, EE% of 38.58 ± 6.06, DL% of 5.36 ± 0.83, swelling % of 859.90 ± 33.49, RE % of 78.49 ± 0.21, UTS of 0.79 ± 0.13 MPa and Young's moduli of 20.91 ± 2.13 MPa. The physical state of HPN in optimized hybrid nanofibers was examined and the related XRD analysis revealed that HPN was either molecularly dispersed, or it existed in an amorphous state in the nanofibers. The in vivo studies also demonstrated that the wound healing rate in the case of HPN loaded nanofibers was higher when compared with other groups. Moreover, according to H&E and MT stain results, HPN loaded nanofibers did promote the regeneration of skin more effectively, as compared with HPN -free nanofibers. Overall, HPN loaded nanofibers mats prepared in this study have the potential to serve as wound dressings.

In-vitro and in-vivo evaluation of chitosan-based thermosensitive gel containing lorazepam NLCs for the treatment of status epilepticus

The objective of this study was to develop an in-situ gel containing lorazepam (LZM) loaded nanostructured lipid carriers (NLCs) for direct nose-to-brain delivery in order to increase drug therapeutic efficacy in the treatment of epilepsy. Accordingly, LZM loaded NLCs were formulated using emulsification solvent diffusion and evaporation method; then the effects of the formulation variables on different physicochemical characteristics of NLCs were investigated. Thermosensitive in-situ gels containing LZM-NLCs were prepared using a combination of chitosan and β-glycerol phosphate (β-GP). The anticonvulsant efficacy of LZM-NLCs-Gel was then examined using the pentylenetetrazole (PTZ) model. The optimised NLCs were spherical, showing the particle size of 71.70 ± 5.16 nm and the zeta potential of -20.06 ± 2.70 mV. The pH and gelation time for the chitosan solution with 15% (w/v) β-GP were determined to be 7.12 ± 0.03 and 5.33 ± 0.58 min, respectively. The in-vivo findings showed that compared with the control group and the group that received LZM-Gel, the occurrence of PTZ-induced seizures in the rats was significantly reduced by LZM-NLCs-Gel after intranasal administration. These results, therefore, suggested that the LZM-NLCs-Gel system could have potential applications for brain targeting through nasal route and might increase LZM therapeutic efficacy in the treatment of epilepsy.

Novel Nanocarriers for the Treatment of Wound Healing

The sequence of biochemical and cellular responses restoring the integrity of the subcutaneous tissue of the skin is termed as wound healing. Inflammatory cytokine suppression and inflammatory transduction cascades are the major targets for wound healing. Formulations for wound healing should promote neovascularization and angiogenic pathways by increasing the expression of vascular endothelial growth factor, fibroblast growth factor, and platelet-derived growth factor. Medication used for wound healing promotes antiinflammatory associated with anti-bacterial action. In order to boost the effectiveness of current medical treatments, the cutting-edge nanotechnology offers many novel therapies. This review summarized and discussed wound healing, types of wounds, natural materials used for wound healing, metallic nanoparticles and current nano drug delivery systems used for wound healing with special emphasis on the angiogenesis role in the healing of wounds.

Lipid Nanoparticles as a Skin Wound Healing Drug Delivery System: Discoveries and Advances

Chronic wounds are a remarkable cause of morbidity, requiring long-time treatments with a significant impact on the quality of life and high costs for public health. Although there are a variety of topical skin preparations commercially available, they have several limitations that frequently impair wound healing, such as drug instability, toxicity, limited time of action and ineffective skin permeation. In recent years, researchers have focused on the development of new effective treatments for wound healing and shown frequent interest in nanometric drug delivery systems to overcome such obstacles. In dermatology, lipid nanoparticles (LNPs) have received great attention from researchers due to their great functionalities, greater adhesion to the skin and film formation, enabling the hydration and maintenance of skin integrity, as well as present a more effective penetration through the skin barrier. This review provides an update on topical formulations based on Solid Lipid Nanoparticles (SLNs) and Nanostructured Lipid Carriers (NLCs) as wound healing treatments. Both SLNs and NLCs are able to increase solubility and stability of active pharmaceutical ingredients and increase skin penetration compared to the free drugs. Additionally, SLNs and NLCs can increase pharmacological activity, increase the release profile of the drugs, promote synergistic effects and improve the sensory properties of the final formulation. Topical dosage forms containing nanoparticles have been extensively evaluated for wound healing activity, mainly the dressings, films and scaffolds. Therefore, lipid nanoparticles have contributed in improving wound healing therapies when incorporated into other dosage forms with better efficacy and lesser adverse effects than conventional formulations.

Carboxymethyl cellulose-based wafer enriched with resveratrol-loaded nanoparticles for enhanced wound healing

The present study aimed to prepare and investigate the wound healing potential of carboxymethyl cellulose (CMC)-based wafers incorporated with resveratrol (RSV)-loaded cellulose acetate butyrate (CAB) NPs. Accordingly, RSV-CAB NPs were prepared using the solvent evaporation method. The effect of different formulation parameters (polymer content, surfactant concentration, and the volume ratio of aqueous phase to organic phase) on the properties of NPs was investigated using the Box-Behnken design. Then, the optimized NPs were incorporated in wafers comprising CMC combined with hydroxyl propyl methyl cellulose (HPMC) or chitosan. Hydration capacity, porosity, adhesive strength, and hardness of the prepared nanocomposite wafers were examined. Optimized formulation was spherical, showing the particle size, polydispersity index, zeta potential, encapsulation efficiency %, drug loading %, and release efficiency % of 248.5 nm, 0.38, - 1.59, 87.58, 25.94, and 67.10, respectively. The CMC-HPMC wafers exhibited higher porosity, hydration capacity, and adhesive performance, as compared with the CMC wafers alone and CMC-chitosan wafers. Wound healing test and histological evaluation in the excisional wounds of the rats showed that the RSV-NPs-wafers were more effective as a healing accelerator, in comparison to wafers without drug or those containing the free RSV. These results demonstrated the potential of the RSV-NPs-wafer in wound healing drug delivery applications. Graphical abstract.

Itraconazole lipid nanocapsules gel for dermatological applications: In vitro characteristics and treatment of induced cutaneous candidiasis

There is a growing clinical demand for topical itraconazole (ITC) delivery systems because of the expanding potential of the drug for topical fungal and non-fungal applications. Lipid-based nanocarriers offer great promise in this respect. In the present study, a new topical ITC gel based on lipid nanocapsules (LNC) was developed. ITC-LNC were compared to ITC-loaded nanostructured lipid carriers (ITC-NLC) with more established benefits as topical vectors. Both nanocarriers showed high entrapment efficiency (EE > 98%). Compared to ITC-NLC, the ITC-LNC showed a significantly smaller particle size (∼50 vs 155 nm), narrower size distribution (0.09 vs 0.38), faster initial release rate under sink conditions and greater in vitro antifungal activity against Candida albicans (C. albicans) (inhibition zone 29.4 vs 26.4 mm). ITC-LNC and ITC-NLC-based gels significantly enhanced the dermal retention of ITC in excised human skin relative to a conventional ITC gel. Histopathological assessment of a 14-day treatment of induced cutaneous candidiasis in a rat model indicated efficacy of the gel preparations. Fungal elements developed in the superficial epidermal skin layer were cleared by the end of treatment. Equally important, no histopathological changes in the epidermal and dermal layers of rat skin were observed. Findings of this study verified efficacy of topical ITC in the treatment of superficial fungal infections as well as effectiveness of LNC as biomimetic nanocarrier for dermal drug delivery. Combining ITC and LNC would present a bioactive nanocarrier system with good potentials for fungal infections and other skin applications.

Development of polyurethane foam dressing containing silver and asiaticoside for healing of dermal wound

Polyurethane foam dressings for dermal wounds were formulated with natural polyols in order to improve the foam characteristics and the release of 2 active agents, silver and asiaticoside (AS) as an antimicrobial agent and an herbal wound healing agent, respectively. The foam was instantly formed by interaction of polyols and diisocyanate. Hydroxypropyl methylcellulose, chitosan and sodium alginate were individually mixed with the main polyols, polypropylene glycol, in the formulation while the active components were impregnated into the obtained foam dressing sheets. Although the type and amount of the natural polyols slightly affected the pore size, water sorption-desorption profile and compression strength of the obtained foam sheets, a prominent effect was found in the release of both active components. Among natural polyols formulations, foam sheets with alginate showed the highest silver and AS release. Non-cytotoxicity of these foam sheets to human fibroblast cells was confirmed. Antimicrobial testing on four bacteria strains showed that 1 mg/cm2 silver in formulations with 6% of natural polyols and without natural polyols had sufficient content of the silver release with comparable inhibition zone and significantly larger zone than other formulations. In pig study, the foam dressing with 6% alginate, 1 mg/cm2 silver and 5% AS could improve wound healing in both the percentage of the wound closure and histological parameters of the dermal wound without any dermatologic reactions. In conclusion, this innovative foam dressing had potential to be a good candidate for wound treatment.