The ban on the use of animals in testing cosmetic products has led to the development of animal-free in vitro methods. Strat-M^® is an artificial membrane engineered to mimic human skin and is recommended as a replacement for skin. However, its usefulness in the assessment of the permeation of cosmetics in in-use conditions remains unverified. No data have been published on its comparative performance with the membrane of choice, porcine skin. The comparative permeability characteristics of Strat-M^® and porcine skin were investigated using Franz diffusion cells. Caffeine (CF) and rhododendrol (RD) in complex vehicles with varying concentrations of polyols were applied as finite and infinite doses. Good rank orders of permeation from finite dose experiments were observed for RD. High correlations were observed in RD permeation between Strat-M^® and porcine skin under finite and infinite dose conditions, whereas only finite dose conditions for CF were associated with good correlations. Permeation from formulations with high polyol content and residual formulations was enhanced due to the disruption of the integrity of the Strat-M^® barrier. The usefulness of Strat-M^® in the assessment of dermal permeation may be limited to finite dose conditions and not applicable to infinite dose conditions or formulations applied in layers.

Breast cancer (BC) is one of the most frequently diagnosed cancers in women. Chemotherapy continues to be the treatment of choice for clinically combating it. Nevertheless, the chemotherapy process is frequently hindered by multidrug resistance, thereby impacting the effectiveness of the treatment. Multidrug resistance (MDR) refers to the phenomenon in which malignant tumour cells develop resistance to anticancer drugs after one single exposure. It can occur with a broad range of chemotherapeutic drugs with distinct chemical structures and mechanisms of action, and it is one of the major causes of treatment failure and disease relapse. Research has long been focused on overcoming MDR by using multiple drug combinations, but this approach is often associated with serious side effects. Therefore, there is a pressing need for in-depth research into the mechanisms of MDR, as well as the development of new drugs to reverse MDR and improve the efficacy of breast cancer chemotherapy. This article reviews the mechanisms of multidrug resistance and explores the application of nano-drug delivery system (NDDS) to overcome MDR in breast cancer. The aim is to offer a valuable reference for further research endeavours.

Ellagic acid (EA), a natural polyphenol found in berries, has high antioxidant capacity. This study aimed to improve EA solubility by complex formation with urea (UR) using solvent evaporation method and evaluate its solubility, antioxidant capacity, and physical properties. The solubility test (25 °C, 72 h) showed that the solubility of EVP (EA/UR = 1/1) was approximately two-fold higher than that of EA (7.13 µg/mL versus 3.99 µg/mL). Moreover, the IC₅₀ values of EA and EVP (EA/UR = 1/1) (1.50 µg/mL and 1.30 µg/mL, respectively) showed higher antioxidant capacity of EVP than that of EA. DSC analysis revealed that the UR peak at 134 °C disappeared, and a new endothermic peak was observed at approximately 250 °C for EVP (EA/UR = 1/1). PXRD measurements showed that the characteristic peaks of EA at 2θ = 12.0° and 28.0° and of UR at 2θ = 22.0°, 24.3°, and 29.1° disappeared and that new peaks were identified at 2θ = 10.6°, 18.7°, and 26.8° for EVP (EA/UR = 1/1). According to 2D NOESY NMR spectroscopy, cross-peaks were observed between the -NH and -OH groups, suggesting intermolecular interactions between EA and UR. Therefore, complexation was confirmed in EA/UR = 1/1 prepared by solvent evaporation, suggesting that it contributed to the improvement in solubility and antioxidant capacity of EA.

A highly viscous substance was prepared by evaporating an ethanol solution containing two hydrophilic vitamins; vitamin C, and vitamin B6. The viscous substance and physical mixture of the two vitamins were tested using a differential scanning calorimeter and an X-ray diffractometer. The highly viscous substance was found to be a liquid crystal (LC) made of these two hydrophilic vitamins. Determination by proton nuclear magnetic resonance measurement suggested that intramolecular hydrogen bonding in vitamin B6 was eliminated by the LC formation. This LC compound showed high solubility in 1,3-butanediol (almost 87%). Much higher skin permeation of both vitamin C and B6 was also observed from the LC compound than that from the physical mixture. The present LC compound containing vitamin C and vitamin B6 may be useful for pharmaceutical and cosmeceutical applications.

Cell-based therapy is an excellent therapeutic modality that involves cell transplantation into patients; however, given that most transplanted cells die immediately post-transplantation, the application of this strategy remains limited. Cell encapsulation is a promising technique for prolonging the survival of transplanted cells, although a definitive encapsulation protocol is yet to be established. Herein, we selected sodium alginate as a polymer for cell encapsulation and optimized the structure and function of cell-encapsulating alginate capsules. First, alginate capsules were prepared using various concentrations of sodium alginate and calcium chloride solution. The NanoLuc luciferase (Nluc)-expressing murine mesenchymal stem cell line C3H10T1/2 was used to prepare the alginate capsules, and cell survival was evaluated after transplantation into mice. The structural properties of the alginate capsules were dependent on the preparation conditions. Capsules with adequate hardness were obtained using 1% sodium alginate and 10% calcium chloride solutions. Alginate capsules encapsulating 5 × 10³ C3H10T1/2/Nluc cells/10 μL maintained a constant cell number over time under in vitro culture conditions. After transplantation into mice, C3H10T1/2/Nluc cells encapsulated in alginate capsules exhibited a significantly longer survival (≥40 days) than suspended cells. Based on these findings, cell-encapsulating alginate capsules with optimal properties can be used for long-term cell-based therapies.

Psoriasis is a chronic skin disease characterized by hyperproliferation of keratinocytes and excessive inflammation. Plant-derived nanoparticles (pdNPs) are promising agents for treating inflammatory skin diseases. In this study, we examined the characteristics and functions of rose hip-derived nanoparticles (RNPs) rich in various bioactive compounds. RNPs were isolated from rose hips using sucrose ultracentrifugation and characterized using NanoSight and transmission electron microscopy. Cellular uptake by HaCaT human keratinocytes was analyzed using flow cytometry and confocal microscopy. Uptake mechanisms were investigated using siRNA knockdown. Proliferation, apoptosis, and cytokine expression were evaluated in a HaCaT psoriasis model. Antioxidant activity was assessed by measuring reactive oxygen species (ROS) levels in stimulated HaCaT and RAW264.7 mouse macrophage-like cells. The in vivo efficacy was evaluated in a mouse model of psoriasis via intradermal injection of RNPs. The RNPs obtained via ultracentrifugation exhibited a vesicular structure of approximately 100 nm in diameter. They were efficiently taken up by HaCaT cells and inhibited excessive inflammation-induced proliferation. RNPs reduced the mRNA levels of the inflammatory cytokines, interleukin-1β and interferon-γ. Additionally, RNPs were efficiently internalized by mouse macrophage-like RAW264.7 cells, decreasing the intracellular reactive oxygen species levels. The intradermal injection of RNPs effectively suppressed epidermal hyperproliferation and macrophage infiltration in an imiquimod-induced psoriasis mouse model. Collectively, these results suggest that RNPs can be used to treat psoriasis by regulating oxidative stress and inhibiting epidermal hyperproliferation. RNPs, which exerted potent effects on epidermal cells, target key pathological mechanisms such as oxidative stress and immune-driven keratinocyte proliferation. Therefore, they are promising natural therapeutic agents for psoriasis.