New Developments for Fractional CO2 Resurfacing for Skin Rejuvenation and Scar Reduction

Enhancing laser therapy procedure through surface temperature control in multi-layered skin tissue

Laser therapy is extensively utilized in dermatology and medicine due to its ability to precisely target tissues, particularly for skin rejuvenation and colla-gen stimulation. However, the complex interactions between laser irradiation and multilayered skin structures remain insufficiently understood. This study presents a two-dimensional dual-phase-lag heat conduction model to simu-late the temperature distribution in multilayered skin subjected to pulsating laser irradiation. The model incorporates the distinct optical and thermal properties of different skin layers, enhancing the accuracy of heat transfer analysis. To regulate laser intensity and maintain surface temperature within a predefined range, a proportional-integral-derivative (PID) control system is implemented. Experimental validation using an agar-based phantom shows strong agreement with simulation results, confirming the model's reliability. The results further indicate that the PID control system effectively maintains the target temperature with minimal overshoot. However, while surface temperature remains regulated, deeper skin layers may experience higher peak temperatures, emphasizing the need for improved subsurface thermal monitoring, particularly in high absorption treatments. Additionally, the study systematically analyzes the influence of PID gain parameters on temperature regulation, highlighting their impact on system stability and response time. These findings underscore the critical role of integrated control systems in laser-based thermal therapies, enhancing precision, safety, and clinical efficacy. The proposed framework provides a robust foundation for real-time temperature management, contributing to more reliable and effective medical applications of laser technology.

Knowledge, attitude, and practice of aesthetic medicine practitioners towards laser and/or light therapy for hypertrophic scars

This study investigated the knowledge, attitude, and practice (KAP) of aesthetic medicine practitioners concerning laser and/or light therapy for hypertrophic scars. Conducted at Hebei Medical University Third Hospital from December 25, 2023, to January 7, 2024, the cross-sectional study utilized a self-administered questionnaire to gather socio-demographic data and KAP scores. A total of 424 valid questionnaires were collected, with 220 (52.26%) female participants. The mean scores were 27.24 ± 4.28 for knowledge (range 8-40), 34.14 ± 3.49 for attitude (range 9-45), and 26.22 ± 3.46 for practice (range 6-30). Significant positive correlations were observed between knowledge and attitude (r = 0.471, P < 0.001), knowledge and practice (r = 0.593, P < 0.001), and attitude and practice (r = 0.640, P < 0.001). Multivariate logistic regression revealed that both knowledge (OR = 1.260, P < 0.001) and attitude scores (OR = 1.547, P < 0.001), along with the intermediate professional title (OR = 0.233, P = 0.042), were significantly associated with proactive practice. The findings indicate a need for targeted educational initiatives to enhance practitioners' knowledge in this area.

Advancements in laser technologies for skin rejuvenation: A comprehensive review of efficacy and safety

INTRODUCTION

Laser technology has fundamentally transformed the landscape of dermatology, offering nuanced solutions for skin rejuvenation and resurfacing. This paper aims to explore the spectrum of laser technologies, from ablative to non-ablative and fractional lasers, their mechanisms, benefits, and tailored applications for diverse skin conditions. As we delve into the intricacies of each technology, we also consider the scientific advancements that have made these treatments safer and more effective, promising a new horizon in skin rejuvenation.

OBJECTIVE

This comprehensive analysis seeks to evaluate recent advancements in laser technology for skin rejuvenation, focusing on efficacy, safety, and patient satisfaction.

METHODS

The selection criteria for studies in this publication focused on recent, peer-reviewed articles from the last 20 years, emphasizing advancements in laser technologies for skin rejuvenation. Our comprehensive review involved searches in PubMed, Cochrane, Scopus and Google Scholar using keywords like "skin rejuvenation," "laser technology," "efficacy," "safety," and "dermatology." This approach focused on inclusion of recent research and perspectives on the efficacy and safety of laser treatments in the field of dermatology.

RESULTS

Our literature review reveals advancements in laser skin resurfacing technologies, notably fractional lasers for minimal downtime rejuvenation, ablative lasers for precise tissue vaporization, and non-ablative lasers for coagulation effect promoting collagen with reduced recovery. Hybrid and picosecond lasers are highlighted for their versatility and effectiveness in addressing a wide array of skin concerns. The findings also emphasize the development of safer treatment protocols for ethnic skin, significantly reducing risks like hyperpigmentation and scarring, thus broadening the scope of effective dermatological solutions.

CONCLUSION

This extensive review of advancements in laser technologies for skin rejuvenation underscores a remarkable evolution in dermatological treatments, offering an expansive overview of the efficacy, safety, and patient satisfaction associated with these interventions. Furthermore, the exploration of combination treatments and laser-assisted drug delivery represents a frontier in dermatological practice, offering synergistic effects that could amplify the therapeutic benefits of laser treatments.

Delayed Collagen Production without Myofibroblast Formation Contributes to Reduced Scarring in Adult Skin Microwounds

In adult mammals, wound healing predominantly follows a fibrotic pathway, culminating in scar formation. However, cutaneous microwounds generated through fractional photothermolysis, a modality that produces a constellation of microthermal zones, exhibit a markedly different healing trajectory. Our study delineates the cellular attributes of these microthermal zones, underscoring a temporally limited, subclinical inflammatory milieu concomitant with rapid re-epithelialization within 24 hours. This wound closure is facilitated by the activation of genes associated with keratinocyte migration and differentiation. In contrast to macrothermal wounds, which predominantly heal through a robust myofibroblast-mediated collagen deposition, microthermal zones are characterized by absence of wound contraction and feature delayed collagen remodeling, initiating 5-6 weeks after injury. This distinct wound healing is characterized by a rapid re-epithelialization process and a muted inflammatory response, which collectively serve to mitigate excessive myofibroblast activation. Furthermore, we identify an initial reparative phase characterized by a heterogeneous extracellular matrix protein composition, which precedes the delayed collagen remodeling. These findings extend our understanding of cutaneous wound healing and may have significant implications for the optimization of therapeutic strategies aimed at mitigating scar formation.

Does Platelet-Rich Plasma Promote Facial Rejuvenation? Revising the Latest Evidence in a Narrative Review

Facial aging is characterized by progressive macroscopic, histological, and molecular changes. Due to its regenerative and rejuvenating properties, the use of platelet-rich plasma (PRP) as a facial antiaging agent has gained popularity over the last decade. In order to gather and evaluate the latest evidence focusing on the effect of PRP on facial skin rejuvenating, a search through MEDLINE (PubMed) using relevant keywords, inclusion, and exclusion criteria was performed. A total of 539 articles were initially retrieved, and from those, 16 were included in the review. Treatment protocols comprised the use of PRP both in monotherapy and in combination with other substances and by means of direct injection or topical application following skin permeation. The selected studies presented high variability regarding PRP preparation methods, administration protocols, and results assessment. In most studies, PRP seemed to improve to some degree the signs of facial aging, such has wrinkles, skin quality, and pigmentation, accompanied by significant histological and molecular responses. Optimizing treatment protocols should be the next step in assessing the full potential of PRP.

TFOS Lifestyle: Impact of cosmetics on the ocular surface

In this report the use of eye cosmetic products and procedures and how this represents a lifestyle challenge that may exacerbate or promote the development of ocular surface and adnexal disease is discussed. Multiple aspects of eye cosmetics are addressed, including their history and market value, psychological and social impacts, possible problems associated with cosmetic ingredients, products, and procedures, and regulations for eye cosmetic use. In addition, a systematic review that critically appraises randomized controlled trial evidence concerning the ocular effects of eyelash growth products is included. The findings of this systematic review highlight the evidence gaps and indicate future directions for research to focus on ocular surface outcomes associated with eyelash growth products.

The Role of Physical Therapies in Wound Healing and Assisted Scarring

Wound healing (WH) is a complex multistep process in which a failure could lead to a chronic wound (CW). CW is a major health problem and includes leg venous ulcers, diabetic foot ulcers, and pressure ulcers. CW is difficult to treat and affects vulnerable and pluripathological patients. On the other hand, excessive scarring leads to keloids and hypertrophic scars causing disfiguration and sometimes itchiness and pain. Treatment of WH includes the cleaning and careful handling of injured tissue, early treatment and prevention of infection, and promotion of healing. Treatment of underlying conditions and the use of special dressings promote healing. The patient at risk and risk areas should avoid injury as much as possible. This review aims to summarize the role of physical therapies as complementary treatments in WH and scarring. The article proposes a translational view, opening the opportunity to develop these therapies in an optimal way in clinical management, as many of them are emerging. The role of laser, photobiomodulation, photodynamic therapy, electrical stimulation, ultrasound therapy, and others are highlighted in a practical and comprehensive approach.

Evaluating resurfacing modalities in aesthetics

Skin resurfacing for cutaneous rejuvenation has evolved with the development of a plethora of nonsurgical and minimally invasive modalities. We have highlighted the advances in laser therapy, chemical peels, radiofrequency, microneedling, and platelet-rich plasma therapy. We have also included studies providing head-to-head comparisons between procedures and discussed relevant debates in the field. We have examined additionally combination treatments and resurfacing in acne scars, melasma, and skin of color.

"Split-Face" Evaluation of Collagen Changes Induced by Periorbital Fractional CO2 Laser Resurfacing

BACKGROUND

Periorbital fractional CO2 laser resurfacing has been employed for facial rejuvenation purposes. However, to the best of our knowledge, no study has objectively assessed periorbital neoformation and remodeling of local cutaneous collagen, in a split-face model, from skin samples obtained during upper blepharoplasty.

OBJECTIVES

The authors sought to objectively evaluate neoformation and remodeling of local cutaneous collagen after periorbital skin fractional CO2 laser resurfacing.

METHODS

Sixteen female patients presenting with dermatochalasis and periorbital rhytids were evaluated in a prospective and comparative study. All patients underwent unilateral periorbital fractional CO2 laser resurfacing 30 days before upper blepharoplasty. Quantification of types I and III collagen from laser-treated and untreated eyelid skin samples obtained during upper blepharoplasty was assessed with histochemical analysis (Picrosirius Red staining). Laser resurfacing treatment was applied to the untreated side immediately after the upper blepharoplasty. Two blinded, independent physicians evaluated clinical improvement in pretreatment and 1- and 6-month posttreatment digital images.

RESULTS

Histochemical analysis showed significantly higher intensity in collagen types I (treated: 158.7 ± 5.3, untreated: 139.2 ± 5.0; P < 0.0001) and III (treated: 105.1 ± 7.7, untreated: 104.1 ± 7.1; P < 0.0001) in the fractional CO2 laser treatment samples; a greater difference was detected in collagen type I. A significant improvement in periorbital rhytidosis was observed 1 month after laser resurfacing (23%); a greater improvement in the periorbital region was observed 6 months after laser resurfacing and upper blepharoplasty (43.67%).

CONCLUSIONS

Periorbital fractional CO2 laser resurfacing was an effective method to improve palpebral skin, with histochemical evidence of increase in collagen types I and III.

LEVEL OF EVIDENCE: 4

Extracellular Vesicles of GMSCs Alleviate Aging-Related Cell Senescence

Healthy aging is a complex biological process with progressive accumulation of senescent cells characterized by stable cell cycle arrest, resulting in impaired homeostasis, regenerative potential, and gradual functional decline in multiple tissues and organs, whereby the aberrant activation of mammalian target of rapamycin (mTOR) signaling networks plays a central role. Herein, we explored the effects of extracellular vesicles (EVs) released by gingiva-derived mesenchymal stem cells (GMSC-EVs) on oxidative stress-induced cellular senescence in human endothelial cells and skin fibroblasts and their antiaging potentials. Our results showed that GMSC-EVs robustly abrogated oxidative stress-induced upregulation in the expression of cellular senescence-related genes, such as β-galactosidase, p21, p53, and γH2AX, and mTOR/pS6 signaling pathway, in human umbilical vein endothelial cells (HUVECs) and skin fibroblasts. Meanwhile, GMSC-EVs restored oxidative stress-induced impairment in proliferation and tube formation by HUVECs. Systemic administration of GMSC-EVs attenuated aging-associated elevation in the expression levels of p21, mTOR/pS6, interleukin 6, and tumor necrosis factor α in skin and heart tissues of aged mice. These findings suggest that GMSC-EVs could be a potential alternative source of cell-free product for attenuation of aging-related skin and vascular dysfunctions due to their potent inhibitory effects on oxidative stress-induced cellular senescence in endothelial cells and skin fibroblasts.