A systematic review and meta-analysis of efficacy, safety, and satisfaction rates of laser combination treatments vs laser monotherapy in skin rejuvenation resurfacing

Photoaging: Current Concepts on Molecular Mechanisms, Prevention, and Treatment

Photoaging is the consequence of chronic exposure to solar irradiation, encompassing ultraviolet (UV), visible, and infrared wavelengths. Over time, this exposure causes cumulative damage, leading to both aesthetic changes and structural degradation of the skin. These effects manifest as rhytids, dyschromia, textural changes, elastosis, volume loss, telangiectasias, and hyperkeratosis, collectively contributing to a prematurely aged appearance that exceeds the skin's chronological age. The hallmarks of photoaging vary significantly by skin phototype. Skin of color tends to exhibit dyschromia and features associated with "intrinsic" aging, such as volume loss, while white skin is more prone to "extrinsic" aging characteristics, including rhytids and elastosis. Moreover, susceptibility to different wavelengths within the electromagnetic spectrum also differs by skin phototype, influencing the clinical presentation of photoaging, as well as prevention and treatment strategies. Fortunately, photoaging-and its associated adverse effects-is largely preventable and, to some extent, reversible. However, effective prevention and treatment strategies require careful tailoring to an individual's skin type. In this review, we summarize molecular mechanisms underlying photoaging, examine its clinical manifestations, outline risk factors and prevention strategies, and highlight recent advancements in its treatment.

Non-Surgical Management of the Periorbital Area

Non-surgical rejuvenation of the periorbital area is becoming increasingly popular given the downtime and risks associated with surgical procedures. Dermabrasion and chemical peels were first used along with neuromodulators and dermal fillers. Over the past few decades, laser treatments have emerged as the gold standard for periorbital skin resurfacing. The laser treatments are categorized by ablative and non-ablative lasers and further subcategorized into fractionated and non-fractionated lasers. Radiofrequency-based devices have also emerged as a beneficial non-surgical treatment for the periorbital area. Within this section, the authors explore the various non-surgical treatments for periorbital rejuvenation.

Combined multilevel anti-aging strategies and practical applications of dermocosmetics in aesthetic procedures

Management of the signs of facial aging and other cosmetic skin problems have greatly evolved in the past years. People are also seeking to improve their well-being and global skin appearance, and when they consider using cosmetic procedures, they expect natural and long-lasting aesthetic results. Combined dermocosmetic approaches that address the signs of facial aging at all levels are increasingly being used by dermatologists to meet patient expectations while ensuring their safety. Minimally invasive and reversible procedures that can be performed in only one session are popular approaches for skin restructuring and volumizing as they are flexible, rapid and less burdensome for patients. These interventions can achieve even better outcomes when they are combined with cosmeceuticals as pre- or post-procedural adjuvants to prepare the skin, accelerate recovery and sustain results. The use of topical dermocosmetics is also recommended as part of the daily skin care routine to improve skin quality and help maintain skin barrier function. This review thus outlines the most commonly used combined multilevel anti-aging strategies, which start by addressing the deepest skin layers and then the more superficial signs of skin aging. Examples of multi-active cosmeceuticals and skin delivery enhancing systems are also presented, together with examples of the use of dermocosmetics as supportive care for aesthetic procedures, to provide insights into current applications of dermocosmetic products.

Deep learning automatically assesses 2-µm laser-induced skin damage OCT images

The present study proposed a noninvasive, automated, in vivo assessment method based on optical coherence tomography (OCT) and deep learning techniques to qualitatively and quantitatively analyze the biological effects of 2-µm laser-induced skin damage at different irradiation doses. Different doses of 2-µm laser irradiation established a mouse skin damage model, after which the skin-damaged tissues were imaged non-invasively in vivo using OCT. The acquired images were preprocessed to construct the dataset required for deep learning. The deep learning models used were U-Net, DeepLabV3+, PSP-Net, and HR-Net, and the trained models were used to segment the damage images and further quantify the damage volume of mouse skin under different irradiation doses. The comparison of the qualitative and quantitative results of the four network models showed that HR-Net had the best performance, the highest agreement between the segmentation results and real values, and the smallest error in the quantitative assessment of the damage volume. Based on HR-Net to segment the damage image and quantify the damage volume, the irradiation doses 5.41, 9.55, 13.05, 20.85, 32.71, 52.92, 76.71, and 97.24 J/cm² corresponded to a damage volume of 4.58, 12.56, 16.74, 20.88, 24.52, 30.75, 34.13, and 37.32 mm³. The damage volume increased in a radiation dose-dependent manner.

Synthesis and Properties of Injectable Hydrogel for Tissue Filling

Hydrogels with injectability have emerged as the focal point in tissue filling, owing to their unique properties, such as minimal adverse effects, faster recovery, good results, and negligible disruption to daily activities. These hydrogels could attain their injectability through chemical covalent crosslinking, physical crosslinking, or biological crosslinking. These reactions allow for the formation of reversible bonds or delayed gelatinization, ensuring a minimally invasive approach for tissue filling. Injectable hydrogels facilitate tissue augmentation and tissue regeneration by offering slow degradation, mechanical support, and the modulation of biological functions in host cells. This review summarizes the recent advancements in synthetic strategies for injectable hydrogels and introduces their application in tissue filling. Ultimately, we discuss the prospects and prevailing challenges in developing optimal injectable hydrogels for tissue augmentation, aiming to chart a course for future investigations.