Arash Goodarzi

Background: Taurine is a bioactive amino acid that has great potential for wound healing, but it struggles with poor skin penetration and quick clearance. This study aimed to develop taurine-loaded nanoliposomes (Nlp-Tau) to enable sustained local delivery and improve effectiveness. Methods: Nlp-Tau were prepared using thin-film hydration. We characterized them for size, charge, shape, encapsulation efficiency (EE%), loading efficiency (LE%), and in vitro release. Also, its biocompatibility on human foreskin fibroblasts (HFF) with a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT assay) has been assessed. In vitro wound healing potential was further evaluated using a scratch assay. Results: Optimized Nlp-Tau showed favorable properties, including an average hydrodynamic diameter of about 282 nm, a polydispersity index of 0.2, a strong negative zeta potential of −31.3 mV, and a spherical shape. However, transmission electron microscopy (TEM) images revealed diameters of about 142 nm and 194 nm for the drug-free and taurine-loaded particles, respectively. Additionally, EE% and LE% were 20% and 2.5%, respectively. In vitro release in PBS (pH 7.4) followed Higuchi kinetics, showing sustained release over 72 h. Nlp-Tau displayed excellent biocompatibility, with HFF viability significantly higher than other groups at concentrations up to 7 mg/mL. Importantly, in the scratch assay, Nlp-Tau treatment resulted in just 6.8% of the wound area remaining after 48 h, which outperformed free taurine at 10.7%. Conclusions: The Nlp-Tau system we developed offers a stable, biocompatible, and effective delivery method for sustained taurine release. It demonstrates greatly improved in vitro wound closure and shows strong potential for future wound care applications.

The resurgence of interest in traditional herbal remedies stems from an increasing appreciation for their complex phytochemical profiles and potential for synergistic therapeutic effects. However, the therapeutic potential of plant extracts is often limited by poor absorption and potential toxicity related to conventional delivery methods. This review explores the application of nanocarrier-mediated delivery systems, such as nanoparticles (NPs), liposomes, and nanoemulsions, to address these challenges. These biocompatible carriers offer enhanced stability and targeted delivery of herbal compounds, improving their efficacy and reducing unwanted side effects. By enabling precise distribution, nanotechnology optimizes the potency of herbal medicine across diverse applications, including regenerative medicine, wound healing, anticancer, and infection treatment. This review provides a systematic description of successful applications of nano-delivery technologies, nanoparticles, liposomes, nanoemulsions, and hybrid carriers, for the targeted delivery of some well-characterized herbal bioactives (curcumin, allicin, berberine, resveratrol etc.) and the enhanced therapeutic performance of herbal bioactives across a variety of preclinical models. Graphical Abstract

Aims: Thymus plant is a very useful herbal medicine with various properties such as anti-inflammatory and antibacterial. Therefore, the properties of this plant have made this drug a suitable candidate for wound healing. In this study, hydroxypropyl methylcellulose (HPMC) gel containing Zataria multiflora volatile oil nanoemulsion (neZM) along with polycaprolactone/chitosan (PCL-CS) nanofibrous scaffold was used, and the effect of three experimental groups on the wound healing process was evaluated. The first group, HPMC gel containing neZM, the second group, PCL-CS nanofibers, and the third group, HPMC gel containing neZM and bandaged with PCL-CS nanofibers (PCL-CS/neZM). Wounds bandaged with common sterile gas were considered as control. Methods: The nanoemulsion was synthesized by a spontaneous method and loaded into a hydroxypropyl methylcellulose (HPMC) gel. The DLS test investigated the size of these nanoemulsions. A PCL-CS nanofibrous scaffold was also synthesized by electrospinning method then SEM and contact angle tests investigated morphology and hydrophilicity/hydrophobicity of its surface. The animal study was performed on full-thickness skin wounds in rats, and the process of tissue regeneration in the experimental and control groups was evaluated by H&E and Masson's trichrome staining. Results: The results showed that the nanoemulsion has a size of 225±9 nm and has an acceptable dispersion. The PCL-CS nanofibers synthesized by the electrospinning method also show non-beaded smooth fibers and due to the presence of chitosan with hydrophilic properties, have higher surface hydrophobicity than PCL fibers. The wound healing results show that the PCL-CS/neZM group significantly reduced the wound size compared to the other groups on the 7th, 14th, and 21st days. The histological results also show that the PCL-CS/neZM group could significantly reduce the parameters of edema, inflammation, and vascularity and increase the parameters of fibrosis, re-epithelialization, and collagen deposition compared to other groups on day 21. Conclusion: The results of this study show that the PCL-CS/neZM treatment can effectively improve wound healing.

Biodegradable microparticles are useful vehicles for the controlled release of bioactive molecules in drug delivery, tissue engineering and biopharmaceutical applications. We developed dexamethasone (Dex) encapsulation into tyramine-substituted hyaluronic acid microparticles (Dex-HA-Tyr Mp) mediated by horseradish peroxidase (HRP) crosslinking using a microfluidic device and infollowing crosslinked gelatin (Gela) with proanthocyanidin (PA) as a semi-confined bed hydrogel for the repair of sciatic tissue injury. It was found that the simultaneous use of Dex-HA-Tyr Mp and cross-linked Gela-PA hydrogel improved the physical properties of the hydrogel, including mechanical strength and degradability. The designed composite also provided a sustained release system for Dex delivery to the surrounding sites, demonstrating the applicability of the fabricated hydrogel composite for sciatic nerve tissue engineering and regeneration. The encapsulated cells were viable and showed adequate growth ability and morphogenesis during prolonged incubation in Gela-PA/HA-Tyr Mp hydrogel compared to control conditions. Interestingly, histological analysis revealed a significant increase in the number of axons in the injured sciatic nerve following treatment with Dex-HA-Tyr Mp and injectable Gela-PA hydrogel compared to other control groups. In conclusion, the results demonstrated that fabricated Dex-loaded MPs and injectable hydrogel from biomimetic components are suitable systems for sustained delivery of Dex with adequate biocompatibility and the approach may have potential therapeutic applications in peripheral nerve regeneration. Graphical Abstract

Introduction: Cinnamon is one of the most common spices that has been studied for its anti-inflammatory, antioxidant, and antibacterial properties in wound healing. The purpose of this study was to evaluate the effectiveness of polycaprolactone nanofiber mats coated with chitosan microcapsules loaded with cinnamon essential oil in wound healing. Material and methods: For this purpose, chitosan microcapsules containing cinnamon essential oil (µCS-CiZ) were prepared by ion gelation and PCL nanofibers by electrospinning. The size of the µCS-CiZ and the morphology of nanofibers were evaluated by DLS and FESEM methods. In order to evaluate wound healing, 48 rats in 4 groups of Control, µCS-CiZ, PCL, and PCL + µCS-CiZ and were examined on days 7, 14, and 21 in terms of macroscopy (wound closure rate) and histology (edema, inflammation, vascularity, fibrotic tissue, and re-epithelialization). Results: The particle size of the µCS-CiZ and the diameter of the nanofibers were estimated at about 6.33 ± 1.27 μm and 228 ± 33 nm, respectively. On day 21, both µCS-CiZ and PCL groups showed a significant decrease in wound size compared to the control group (P < 0.001). The PCL + µCS-CiZ group also showed a significant decrease compared to the µCS-CiZ (P < 0.05) and PCL groups (P < 0.05). Histological results showed further reduction of edema, inflammation, and vascularity in granulation tissue and appearance of moderate to marked fibrotic tissue in PCL + µCS-CiZ group compared with the other groups. Conclusion: The results of the study showed that the combined use of PCL + µCS-CiZ indicates a synergistic effect on improving wound healing.

Engineering scaffolds that can not only act as a vehicle for stem cell delivery but also support axon regeneration, may significantly improve the treatment outcome of spinal cord injury (SCI). In this study, we developed chitosan scaffold containing human endometrial stem cells (hEnSCs) and platelet-rich plasma (PRP) to provide a controlled environment for facilitating cell ingrowth and differentiation and also to persuade axon nervous tissue repair. The results showed that 80 µL PRP-loaded chitosan scaffold has excellent hEnSCs viability and can promote the regeneration of nerve fibers and angiogenesis and prevent the formation of scar tissue in the repair of SCI.