Metformin loaded cholesterol-lysine conjugate nanoparticles: A novel approach for protecting HDFs against UVB-induced senescence

Co-Delivery of Valsartan and Metformin from a Thermosensitive Hydrogel-Nanoparticle System Promotes Collagen Production in Proliferating and Senescent Primary Human Dermal Fibroblasts

Aging negatively impacts skin health, notably through the senescent cell phenotype, which reduces collagen production and leads to thinner, more fragile skin prone to injuries and chronic wounds. We designed a drug delivery system that addresses these age-related issues using a hybrid hydrogel-nanoparticle system that utilizes a poly(δ-valerolactone-co-lactide)-b-poly(ethylene-glycol)-b-poly(δ-valerolactone-co-lactide) (PVLA-PEG-PVLA) hydrogel. This hydrogel allows for the local, extended release of therapeutics targeting both proliferating and senescent cells. The PVLA-PEG-PVLA hydrogel entrapped valsartan, and metformin-loaded liposomes functionalized with a fibronectin-mimetic peptide, PR_b. Metformin acts as a senomorphic, reversing aspects of cellular senescence, and valsartan, an angiotensin receptor blocker, promotes collagen production. This combination treatment partially reversed the senescent phenotype and improved collagen production in senescent dermal fibroblasts from both young and old adults. Our codelivery hydrogel-nanoparticle system offers a promising treatment for improving age-related dermal pathologies.

Clinically Actionable Topical Strategies for Addressing the Hallmarks of Skin Aging: A Primer for Aesthetic Medicine Practitioners

In this narrative review, we sought to provide a comprehensive overview of the mechanisms underlying cutaneous senescence, framed by the twelve traditional hallmarks of aging. These include genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, impaired macroautophagy, deregulated nutrient sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, altered intercellular communication, chronic inflammation, and dysbiosis. We also examined how topical interventions targeting these hallmarks can be integrated with conventional aesthetic medicine techniques to enhance skin rejuvenation. The potential of combining targeted topical therapies against the aging hallmarks with minimally invasive procedures represents a significant advancement in aesthetic medicine, offering personalized and effective strategies to combat skin aging. The reviewed evidence paves the way for future advancements and underscores the transformative potential of integrating scientifically validated interventions targeted against aging hallmarks into traditional aesthetic practices.

Chrysin loaded bilosomes improve the hepatoprotective effects of chrysin against CCl4 induced hepatotoxicity in mice

In the present work, chrysin loaded bilosomes were formulated, characterized and evaluated to enhance the hepatoprotective activity of drug. Accordingly, chrysin loaded bilosomes were prepared by applying the thin film hydration method; also, fractional factorial design was used to optimize the production conditions of nanoformulations. The prepared formulations were subjected to different methods of characterization; then the hepatoprotective activity of the optimized one was evaluated in the CCl4 hepatointoxicated mice model. Optimized chrysin loaded bilosomes showed a spherical shape with a particle size of 232.97 ± 23 nm, the polydispersity index of 0.35 ± 0.01, the zeta potential of -44.5 ± 1.27 mv, the entrapment efficiency of 96.77 ± 0.18%, the drug loading % of 6.46 ± 0.01 and the release efficiency of 42.25 ± 1.04 during 48 h. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging assay demonstrated the superiority of the anti-oxidant potential of chrysin loaded bilosomes, as compared to pure chrysin. This was in agreement with histopathological investigations, showing significant improvement in serum hepatic biomarkers of CCl4 intoxicated mice treated with chrysin loaded bilosomes, as compared with free chrysin. These results, thus, showed the potential use of bilosomes to enhance the hepatoprotective activity of chrysin via oral administration.

Topical metformin 30% gel in the treatment of acne vulgaris in women, a split face, placebo-controlled study

Acne vulgaris (AV), a widely common disorder, that negatively affects the quality of life. Metformin is a relatively safe, cheap and well tolerated drug that is widely used in the treatment of Diabetes. Systemic metformin has demonstrated promising results in treating acne, while topically it was studied for melasma and recalcitrant central centrifugal cicatricial alopecia. To study the safety and efficacy of topical metformin 30% in the treatment of AV. Twenty-seven female AV patients were asked to blindly apply metformin and placebo gels to either side of the face for 12 weeks. AV lesion count was performed at baseline, at each visit and 4 weeks after end of treatment. At the end of the treatment period, the treated side showed significant improvement of comedones, papules and nodules but not pustules. Although, lesions count increased 1 month after stopping treatment, comedones and papules numbers were still significantly less on the metformin side compared to placebo. No side effects were reported. The limited number of patients studied and the limited follow-up period. The metformin effect was not studied on cellular and molecular levels. Topical metformin nanoemulsion gel can be a promising safe and effective treatment of AV.

Τhe Endless Beauty of Metformin: Does It Also Protect from Skin Aging? A Narrative Review

Metformin has shown multiple effects beyond its widely known antidiabetic effect. Impressively, it has already been proposed as an anti-aging factor. However, the potentially protective role of metformin in skin aging, the most common manifestation of aging, is not well examined. Existing evidence based on experimental studies suggests a potential anti-aging effect on skin. Proposed molecular skin anti-aging mechanisms of metformin include mainly reduction of nuclear factor kappa B (NF-κB) (p65) activity. Moreover, metformin appears to inhibit ultraviolet B (UVB)-induced secretion of pro-inflammatory cytokines. Nonetheless, data is still limited, and so more studies are needed. Importantly, we need more studies conducted in humans to further examine this interesting potential. Until then, whether oral administration of metformin or local use of the agent could be used to delay skin aging remains to be answered.

Topical ocular delivery of vancomycin loaded cationic lipid nanocarriers as a promising and non-invasive alternative approach to intravitreal injection for enhanced bacterial endophthalmitis management

Vancomycin (VCM) is a drug of choice for treating infections caused by Staphylococcus species, reported being the most causative agent of bacterial endophthalmitis. However, the ocular bioavailability of topically applied VCM is low due to its high molecular weight and hydrophilicity. The current study sought to explore whether the nanostructured lipid carriers (NLCs) fabricated via cold homogenization technique could improve ocular penetration and prolong the ophthalmic residence of VCM. A 2³ full factorial design was adopted to evaluate the influence of different process and formulation variables on VCM-loaded NLC formulae. The optimized formula with the particle size of 96.4 ± 0.71 nm and narrow size distribution showed spherical morphology obtained by AFM and represented sustained drug release up to 67% in 48 h fitted to the Korsmeyer-Peppas model with probably non-Fickian diffusion kinetic. FTIR studies visualized the drug-carrier interactions in great detail. High encapsulation of VCM (74.8 ± 4.3% w/w) in NLC has been established in DSC and PXRD analysis. The optimal positively charged (+ 29.7 ± 0.47 mV) colloidal dispersion was also stable for 12 weeks at both 4 °C and 25 °C. According to in vivo studies, incorporation of VCM in NLC resulted in a nearly 3-fold increase in the intravitreal concentration of VCM after eye-drop instillation over control groups. Besides, microbiological evaluation admitted its therapeutic effect within five days is comparable to intravitreal injection of VCM. Further, the optimized formula was found to be nonirritant and safe for ophthalmic administration in RBC hemolytic assay. Also, fluorescent tracking of NLCs on rabbit's cornea showed an increase in corneal penetration of nanoparticles. Thus, it is possible to infer that the evolved NLCs are promising drug delivery systems with superior attainments for enhanced Vancomycin ophthalmic delivery to the eye's posterior segment and improved bacterial endophthalmitis management.