Context: Polydeoxyribonucleotide (PDRN), a nucleic acid extract derived from trout sperm, has gained attention for its regenerative properties in dermatology and aesthetics. This review evaluates the therapeutic potential of PDRN in various dermatological applications, such as anti-aging, wound healing, hair regeneration, acne scar treatment, and melanogenesis, while focusing on its molecular mechanisms and clinical outcomes. Evidence Acquisition: This is a narrative review of the literature based on articles identified through PubMed, Scopus, and Google Scholar. The literature search included relevant terms such as "Polydeoxyribonucleotide", "Collagen", "Wound Healing", "Aging", "Hair Growth", "Acne Scar", "Melanin", "Angiogenesis", "VEGF", "Purinergic Receptors", and "Platelet-Rich Plasma". Studies published within the last two decades were considered for inclusion, focusing on both preclinical and clinical data that explored the effects of PDRN in dermatology. The review was conducted by synthesizing available evidence from relevant studies rather than following a predefined protocol, allowing for a broader, qualitative summary of the literature. Results: Polydeoxyribonucleotide has demonstrated significant effects in dermatological treatments, including the enhancement of collagen synthesis, skin elasticity improvement, and wrinkle reduction through activation of purinergic A2A receptors. It accelerates wound healing by promoting angiogenesis and upregulating VEGF expression. In a study evaluating VEGF mRNA levels in skin wound samples, PDRN (8 mg/kg, intraperitoneally) resulted in a significant increase in VEGF expression compared to the vehicle group (P < 0.001). In acne scar treatment, PDRN reduces inflammation and supports collagen remodeling. Polydeoxyribonucleotide also inhibits MITF, leading to a reduction in melanogenesis and potential skin-lightening effects. Additionally, PDRN has been shown to promote hair regeneration, increasing hair thickness and supporting follicular growth, with enhanced results when combined with platelet-rich plasma (PRP). Conclusions: Polydeoxyribonucleotide demonstrates considerable potential as a therapeutic agent in treating various dermatological conditions, including wound healing, anti-aging, acne scars, and hair loss. However, further clinical studies, particularly larger trials and investigations of combination therapies, are essential to validate its efficacy and optimize clinical applications.

Nicotinic acetylcholine receptors (nAChRs) are membrane-bound proteins that mediate fast synaptic transmission throughout the nervous system. A functional nAChR subtype is formed by the combination of multiple subunits arranged as homomeric or heteromeric pentamers, each with a distinct pharmacological profile. Disruption of their neurotransmission contributes to various neuropathologies, emphasizing the need for detailed knowledge of receptor structure, function, subunit composition, dynamics, and potential ligand-binding sites. However, their structural complexity as integral membrane proteins has hindered expression in mammalian cell lines and proven even more challenging to crystallize, limiting insights into ligand interactions. Understanding the molecular determinants governing nAChRs function is essential for the rational design of selective therapeutics targeting neurological disorders. The emergence of a chimeric receptor approach has dramatically improved the ability to study these important proteins and opened new avenues for high-throughput screening in drug discovery efforts. This review explains how the design of chimera constructs using soluble homologs, such as AChBP, provides researchers with an immense opportunity to investigate receptor structure–function relationships and subtype-specific properties, thereby facilitating the development of more effective treatments.

Background: Skin aging appears in multiple forms, including wrinkles, sagging, scarring, atrophy, and photoaging. Although each phenotype has distinct biological features, all are rooted in dermal fibroblast dysfunction. This review examines the molecular pathways underlying these conditions and evaluates topical interventions designed to restore skin integrity. Aims: To assess how dermal fibroblast dysfunction contributes to different skin aging phenotypes and to evaluate topical therapies targeting the underlying molecular mechanisms. Methods: A narrative review of the literature was conducted focusing on fibroblast‐related molecular pathways and topical interventions used for skin aging and rejuvenation. Results: UVB radiation contributes to wrinkle formation by activating collagen‐degrading enzymes in the upper dermis, whereas sagging results from UVA‐induced damage to deeper connective tissues and altered fat distribution. Scarring is characterized by excessive fibroblast activation and extracellular matrix overproduction, while atrophy develops through fibroblast senescence and loss of structural support. Photoaging involves oxidative stress and elastin disorganization caused by chronic ultraviolet exposure. Topical agents including retinol, niacinamide, caffeine, asiaticoside, and related compounds stimulate collagen synthesis, reduce matrix degradation, and protect fibroblasts from oxidative damage. Unlike previous reviews that examine skin aging as a single process, this review compares distinct aging phenotypes through the common framework of fibroblast dysfunction and their associated molecular targets. Conclusions: Dermal fibroblast dysfunction is a central mechanism underlying multiple forms of skin aging. Targeting fibroblast‐related pathways with topical therapies may address the biological causes of wrinkles, sagging, scarring, atrophy, and photoaging, supporting more personalized and effective skin rejuvenation strategies.