Simvastatin accelerates the healing process of burn wound in Wistar rats through Akt/mTOR signaling pathway

One Molecule, Many Faces: Repositioning Cardiovascular Agents for Advanced Wound Healing

Chronic wound treatments pose a challenge for healthcare worldwide, particularly for the people in developed countries. Chronic wounds significantly impair quality of life, especially among the elderly. Current research is devoted to novel approaches to wound care by repositioning cardiovascular agents for topical wound treatment. The emerging field of medicinal products' repurposing, which involves redirecting existing pharmaceuticals to new therapeutic uses, is a promising strategy. Recent studies suggest that medicinal products such as sartans, beta-blockers, and statins have unexplored potential, exhibiting multifaceted pharmacological properties that extend beyond their primary indications. The purpose of this review is to analyze the current state of knowledge on the repositioning of cardiovascular agents' use and their molecular mechanisms in the context of wound healing.

Engineering of a decellularized bovine skin coated with antibiotics-loaded electrospun fibers with synergistic antibacterial activity for the treatment of infectious wounds

An ideal antibacterial wound dressing with strong antibacterial behavior versus highly drug-resistant bacteria and great wound-healing capacity is still being developed. There is a clinical requirement to progress the current clinical cares that fail to fully restore the skin structure due to post-wound infections. Here, we aim to introduce a novel two-layer wound dressing using decellularized bovine skin (DBS) tissue and antibacterial nanofibers to design a bioactive scaffold with bio-mimicking the native extracellular matrix of both dermis and epidermis. For this purpose, polyvinyl alcohol (PVA)/chitosan (CS) solution was loaded with antibiotics (colistin and meropenem) and electrospun on the surface of the DBS scaffold to fabricate a two-layer antibacterial wound dressing (DBS-PVA/CS/Abs). In detail, the characterization of the fabricated scaffold was conducted using biomechanical, biological, and antibacterial assays. Based on the results, the fabricated scaffold revealed a homogenous three-dimensional microstructure with a connected pore network, a high porosity and swelling ratio, and favorable mechanical properties. In addition, according to the cell culture result, our fabricated two-layer scaffold surface had a good interaction with fibroblast cells and provided an excellent substrate for cell proliferation and attachment. The antibacterial assay revealed a strong antibacterial activity of DBS-PVA/CS/Abs against both standard strain and multidrug-resistant clinical isolates of Acinetobacter baumannii, Pseudomonas aeruginosa, and Escherichia coli. Our bilayer antibacterial wound dressing is strongly suggested as an admirable wound dressing for the management of infectious skin injuries and now promises to advance with preclinical and clinical research.

Simvastatin-Releasing Nanofibrous Peptide Hydrogels for Accelerated Healing of Diabetic Wounds

Wound healing is one of the major global health concerns in diabetic patients. Simvastatin (SMV) is a poorly soluble oral cholesterol-lowering drug that may aid diabetic wound healing. In the current study, a thixotropic peptide hydrogel of Fmoc-diphenylalanine (FmocFF) containing SMV was designed to accelerate skin wound healing effectively and safely in diabetic mice. FmocFF hydrogels were prepared at various concentrations by using the solvent-triggering technique and characterized by spectroscopic methods such as attenuated total reflection Fourier transform infrared (FT-IR) spectroscopy and fluorimetry. Mechanical behaviors were explored by oscillatory rheology. In model mice, the regenerative potential of the FmocFF-SMV hydrogel was evaluated in terms of wound contraction and closure, tissue regeneration, acute and chronic inflammation, granulation, and re-epithelization. The results showed that FmocFF-SMV hydrogels had an entangled nanofibrous microstructure and shear-thinning characteristics. FmocFF-SMV demonstrated a sustained drug release over 7 days. Compared to the unloaded FmocFF hydrogel, treatment with FmocFF-SMV led to superior diabetic wound recovery and reduced inflammation. Therefore, the utilization of the sustained-release FmocFF-SMV hydrogel formulation could become an attractive choice for topical wound therapy in diabetes patients.

Healing potential of curcumin nanomicelles in cutaneous burn wounds: an in vitro and in vivo study

PURPOSE/AIM OF THE STUDY

Curcumin is the active substance of turmeric and has been shown to enhance the healing potential of burn wounds. However, its high hydrophobicity and rapid degradability are great challenges for its clinical applications. The development of new curcumin formulations may provide a potential solution to these issues.

METHODS AND RESULTS

In this study, we investigated the use of curcumin nanomicelles for wound dressing and evaluated their effects on fibroblast migration and proliferation in vitro. We found that the application of curcumin nanomicelles to the wounds significantly improved wound contraction and increased the expression of transforming growth factor-1 and basic fibroblast growth factor at day 14 of the healing process. Furthermore, curcumin nanomicelles reduced the expression of interleukin-1 at days 7 and 14 post-wounding. Histopathological analysis revealed that the curcumin nanomicelles-treated burn wounds exhibited more organized granulation tissue, improved angiogenesis, and enhanced re-epithelialization. Additionally, the curcumin treatment led to increased hydroxyproline content and enhanced TGF-β1 expression level in the wounds. The in vitro studies also demonstrated that the curcumin nanomicelles induced proliferation and migration of fibroblasts.

CONCLUSION

Overall, our findings suggest that curcumin nanomicelles can be a promising candidate for the treatment of burn wounds.

Mesenchymal stem cells paracrine proteins from three-dimensional dynamic culture system promoted wound healing in third-degree burn models

Recovery of skin function remains a significant clinical challenge for deep burns owing to the severe scar formation and poor appendage regeneration, and stem cell therapy has shown great potential for injured tissue regeneration. Here, a cell-free therapy system for deep burn skin was explored using mesenchymal stem cell paracrine proteins (MSC-PP) and polyethylene glycol (PEG) temperature-sensitive hydrogels. A three-dimensional (3D) dynamic culture system for MSCs' large-scale expansion was established using a porous gelatin microcarrier crosslinked with hyaluronic acid (PGM-HA), and the purified MSC-PP from culture supernatant was characterized by mass spectrometric analysis. The results showed the 3D dynamic culture system regulated MSCs cell cycle, reduced apoptosis, and decreased lactic acid content, and the MSC-PP produced in 3D group can promote cell proliferation, migration, and adhesion. The MSC-PP + PEG system maintained stable release in 28 days of observation in vitro. The in vivo therapeutic efficacy was investigated in the rabbit's third-degree burn model, and saline, PEG, MSC-PP, and MSC-PP + PEG treatments groups were set. The in vivo results showed that the MSC-PP + PEG group significantly improved wound healing, inhibited scar formation, and facilitated skin appendage regeneration. In conclusion, the MSC-PP + PEG sustained-release system provides a potentially effective treatment for deep burn skin healing.

Co-delivery of simvastatin and microRNA-21 through liposome could accelerates the wound healing process

The gene delivery approach, mainly microRNAs (miRNA) as key wound healing mediators, has recently received extensive attention. MicroRNA-21 (miR-21) has strongly impacted wound healing by affecting the inflammation and proliferation phases. Previous studies have also demonstrated the beneficial effect of simvastatin on wound healing. Therefore, we designed a dual-drug/gene delivery system using PEGylated liposomes that could simultaneously attain the co-encapsulation and co-delivery of miRNA and simvastatin (SIM) to explore the combined effect of this dual-drug delivery system on wound healing. The PEG-liposomes for simvastatin and miR-21 plasmid (miR-21-P/SIM/Liposomes) were prepared using the thin-film hydration method. The liposomes showed 85 % entrapment efficiency for SIM in the lipid bilayer and high physical entrapment of miR-21-P in the inner cavity. In vitro studies demonstrated no cytotoxicity for the carrier on normal human dermal fibroblast cells (NHDF) and 97 % cellular uptake over 2 h incubation. The scratch test revealed excellent cell proliferation and migration after treatment with miR-21-P/SIM/Liposomes. For the in vivo experiments, a full-thickness cutaneous wound model was used. The wound closure on day 8 was higher for Liposomal formulation containing miR-21-P promoting faster re-epithelialization. On day 12, all treated groups showed complete wound closure. However, following histological analysis, the miR-21-P/SIM/Liposomes revealed the best tissue regeneration, similar to normal functional skin, by reduced inflammation and increased re-epithelialization, collagen deposition and angiogenesis. In conclusion, the designed miR-21-P/SIM/Liposomes could significantly accelerate the process of wound healing, which provides a new strategy for the management of chronic wounds.

Baicalin, silver titanate, Bletilla striata polysaccharide and carboxymethyl chitosan in a porous sponge dressing for burn wound healing

OBJECTIVE

This study tests the efficacy of Bletilla striata polysaccharide (BSP), carboxymethyl chitosan (CMC), baicalin (BA) and silver titanate (ST) in a wound dressings to fight infection, promote healing and provide superior biocompatibility.

METHODS

The antibacterial activity of BA and ST was evaluated in vitro using the inhibition zone method. BA/ST/BSP/CMC porous sponge dressings were prepared and characterized. The biocompatibility of BA/ST/BSP/CMC was assessed using the cell counting kit-8 assay. The therapeutic effect of BA/ST/BSP/CMC was further investigated using the dorsal skin burn model in Sprague-Dawley rats.

RESULTS

The wound dressing had good antibacterial activity against Escherichia coli and Staphylococcus aureus through BA and ST, while the combination of BSP and CMC played an important role in promoting wound healing. The BA/ST/BSP/CMC porous sponge dressings were prepared using a freeze-drying method with the concentrations of BA and ST at 20 and 0.83 mg/mL, respectively, and the optimal ratio of 5% BSP to 4% CMC was 1:3. The average porosity, water absorption and air permeability of BA/ST/BSP/CMC porous sponge dressings were measured to be 90.43%, 746.1% and 66.60%, respectively. After treatment for 3 and 7 days, the healing rates of the BA/ST/BSP/CMC group and BA/BSP/CMC group were significantly higher than those of the normal saline (NS) group and silver sulfadiazine (SSD) group (P < 0.05). Interleukin-1β expression in the BA/ST/BSP/CMC group at 1 and 3 days was significantly lower than that in the other three groups (P < 0.05). After being treated for 3 days, vascular endothelial growth factor expression in the BA/BSP/CMC group and BA/ST/BSP/CMC group was significantly higher than that in the NS group and SSD group (P < 0.05). Inspection of histological sections showed that the BA/ST/BSP/CMC group and BA/BSP/CMC group began to develop scabbing and peeling of damaged skin after 3 days of treatment, indicating accelerated healing relative to the NS group and SSD group.

CONCLUSION

The optimized concentration of BA/ST/BSP/CMC dressing was as follows: 6 mg BSP, 14.4 mg CMC, 0.5 mg ST and 12 mg BA. The BA/ST/BSP/CMC dressing, containing antibacterial constituents, was non-cytotoxic and effective in accelerating the healing of burn wounds, making it a promising candidate for wound healing. Please cite this article as: Gong YR, Zhang C, Xiang X, Wang ZB, Wang YQ, Su YH, Zhang HQ. Baicalin, silver titanate, Bletilla striata polysaccharide and carboxymethyl chitosan in a porous sponge dressing for burn wound healing. J Integr Med. 2023; 21(5): 487-495.

Statins block mammalian target of rapamycin pathway: a possible novel therapeutic strategy for inflammatory, malignant and neurodegenerative diseases

Inflammation plays a critical role in several diseases such as cancer, gastric, heart and nervous system diseases. Data suggest that the activation of mammalian target of rapamycin (mTOR) pathway in epithelial cells leads to inflammation. Statins, the inhibitors of the 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA), seem to be able to inhibit the mTOR. Statins are considered to have favorable effects on inflammatory diseases by reducing the complications caused by inflammation and by regulating the inflammatory process and cytokines secretion. This critical review collected data on this topic from clinical, in vivo and in vitro studies published between 1998 and June 2022 in English from databases including PubMed, Google Scholar, Scopus, and Cochrane libraries.

Self-Gelling Solid Lipid Nanoparticle Hydrogel Containing Simvastatin as Suitable Wound Dressing: An Investigative Study

Hydrogels, an advanced interactive system, is finding use as wound dressings, however, they exhibit restricted mechanical properties, macroscopic nature, and may not manage high exudate wounds or incorporate lipophilic actives. In this study, we developed a self-gelling solid lipid nanoparticle (SLNs) dressing to incorporate simvastatin (SIM), a lipophilic, potential wound-healing agent, clinically limited due to poor solubility (0.03 mg/mL) and absorption. The study explores unconventional and novel application of SIM. The idea was to incorporate a significant amount of SIM in a soluble form and release it slowly over a prolonged time. Further, a suitable polymeric surfactant was selected that assigned a self-gelling property to SLNs (SLN-hydrogel) so as to be used as a novel wound dressing. SLNs assign porosity, elasticity, and occlusivity to the dressing to keep the wound area moist. It will also provide better tolerance and sensory properties to the hydrogel. SIM loaded SLN-hydrogel was prepared employing an industry amenable high-pressure homogenization technique. The unique hydrogel dressing was characterized for particle size, zeta potential, Fourier transform infra-red spectroscopy, powder X-ray diffraction, differential scanning calorimetry, rheology, and texture. Significant loading of SIM (10% w/w) was achieved in spherical nanoparticule hydrogel (0.3 nm (nanoparticles) to 2 µm (gelled-matrix)) that exhibited good spreadability and mechanical properties and slow release up to 72 h. SLN-hydrogel was safe as per the organization for economic co-operation and development (OECD-404) guidelines, with no signs of irritation. Complete healing of excision wound observed in rats within 11 days was 10 times better than marketed povidone-iodine product. The presented work is novel both in terms of classifying a per se SLN-hydrogel and employing SIM. Further, it was established to be a safe, effective, and industry amenable invention.

Comparing the wound healing effect of a controlled release wound dressing containing curcumin/ciprofloxacin and simvastatin/ciprofloxacin in a rat model: A preclinical study

Inflammation and infection are two main factors predisposing a wound to become a chronic one. Degradable wound dressings involving the controlled release of suitable drugs at the ulcer site are one of the solutions to make wounds healing progress smoothly and rapidly. In this research, biodegradable dressings made of polyglycerol sebacate/polycaprolactone (PGS/PCL) containing curcumin/ciprofloxacin (CUR/CIP) and simvastatin/ciprofloxacin (SIM/CIP) were prepared by using the coaxial electrospinning method. Transmission electron microscopy for uniform core/shell structure, swelling ratio, and drug release pattern of the wound dressings were evaluated. At the in vivo study, histometric, histopathologic, and collagen expression study was performed. The PGS/PCL samples containing SIM/CIP showed a burst release pattern of CIP with a delay in the release of SIM; meanwhile, in the samples containing CUR/CIP, both drugs showed a burst release behavior. No cytotoxicity response was observed in the study groups. The in vivo study showed that wound closure was almost completed only in the SIM/CIP group after 14 days. After 14 days, in the wound treated with SIM/CIP dressing, the amount of collagen deposition and angiogenesis was higher than that of the others. These results clearly showed the effect of SIM/CIP on the improvement of the wound healing efficiency in the long term (14 days) and the effect of CUR/CIP on wound contraction in the short term (4 day). It seems, therefore, that the use of SIM and CUR simultaneously in a wound dressing could cause a synergistic effect in the wound repair.

In-vivo evaluation of Alginate-Pectin hydrogel film loaded with Simvastatin for diabetic wound healing in Streptozotocin-induced diabetic rats

Previously we developed and characterized a novel hydrogel film wound dressing containing Sodium Alginate and Pectin loaded with Simvastatin with multi-functional properties. This study investigated the in-vivo efficacy of the developed wound dressing on type I diabetic wound model. Experiments were performed on male Wistar rats for the period of 21-days. Animals developed diabetes after intraperitoneal injection (50 mg/kg) of Streptozotocin then randomly divided into different groups. On days 7, 14, and 21 of post-wounding, animals were euthanized and the wounds tissue were harvested for analysis. The wound healing rate, hematology and histological analysis, hydroxyproline assay, and Vascular Endothelial Growth Factor A measurements were noted. The results revealed that the wound dressing healed the wounded area significantly (p < 0.05) higher than the control after 21-day treatment and wound closure was ~99% without any adverse systemic reactions. Histological analysis qualitatively revealed an enhanced re-epithelialization and collagen deposition. Moreover, results also showed an improved rate of collagen synthesis and angiogenesis in the group treated with the hydrogel film loaded with Simvastatin. Thus, the present study demonstrated that developed film holds great potential for the acceleration of diabetic wound healing by its pro-angiogenic effect, faster re-epithelialization and increased collagen deposition.