Evaluation of thermodynamic bioeffects of long-pulsed 1064 nm laser in the photothermal lipolysis.

OBJECTIVES: To evaluate the lipolysis effect of air cooling assisted long-pulsed 1064 laser for improving local adiposity. MATERIALS AND METHODS: The second-level (pulse duration of 0.3-60 s) long-pulsed Nd:YAG 1064 nm laser (LP1064 nm) with or without forced-air cooling was used to irradiate ex-vivo subcutaneous adipose tissue (SAT) of pig or human and in-vivo inguinal fat tissue of Sprague Dawley rats. The temperature of skin surface as well as 5 mm deep SAT was monitored by a plug-in probe thermal couple, and the former was confined to 39°C or 42°C during the treatment. Histological analysis of SAT response was evaluated by SAT sections stained with hematoxylin-eosin and oil red O. Ultra-microstructure changes were examined by transmission electron microscopy. A pilot study on human subject utilizing LP1064 nm laser with air cooling was conducted. The changes in gross abdomen circumference and ultrasonic imaging were studied. RESULTS: Histological examination showed that LP1064 nm laser treatment induced adipocyte injury and hyperthermic lipolysis both in- and ex-vivo. It was also confirmed by clinical practice on patients. By real-time temperature monitoring, we found that in comparison with LP1064 nm laser alone, additional air cooling could increase the temperature difference between epidermis and SAT, promoting heat accumulation deep in fat tissue, as well as providing better protection for epidermis. CONCLUSION: LP1064 nm laser provided reliable adipose tissue thermolysis when the temperature of skin surface was sustained at 39°C or 42°C for 10 min. Application of air-cooling during the laser treatment achieved better effect and safety of photothermal lipolysis. LP1064 nm laser, as a noninvasive device, has comparable thermal lipolysis effect as other common heat-generating devices.

Laser treatment for Cafe-au-lait Macules: a systematic review and meta-analysis.

Nowadays, laser is the mainstay treatment for cafe-au-lait macules (CALMs), but no systematic review has been published to demonstrate the overall efficacy and it's still controversial which type of laser is optimal. Thus, we conduct the meta-analysis to evaluate the effectiveness and side effects of various types of lasers in treating CALMs. Original articles reporting the efficacy and side effects for CALMs in laser treatment were identified in PubMed, EMBASE, and Web of Science from 1983 to April 11, 2023. Using R software and the 'meta' package, meta-analysis was conducted for clearance and recurrence for evaluation of efficacy. And the occurrence of hypopigmentation and hyperpigmentation rate was pooled for safety evaluation. We used RoB2 and ROBINS-I tools to assess the risks of bias in RCT studies and non-RCT studies, respectively. The Grading of Recommendations, Assessment, Development and Evaluation system was used to assess the quality of the evidence. Nineteen studies involving 991 patients were included, which had a very low to moderate quality of evidence. The pooled 75% clearance rate was 43.3% (95% CI 31.8-54.7%, I2 = 96%), 50% clearance rate was 75% (95% CI 62.2-85.9%, I2 = 89%) and the recurrence rate was 13% (95% CI 3.2-26.5%, I2 = 88%). The pooled hypopigmentation and hyperpigmentation rates were 1.2% (95% CI 0.3-2.1%, I2 = 0%) and 1.2% (95% CI 0.3-2%, I2 = 0%), respectively. Subgroup analysis revealed that QS-1064-nm Nd:YAG laser treatment not only achieved more than 75% clearance rate in 50.9% of patients (95% CI 26.9-74.4%, I2 = 90%) but also resulted in the lowest hypopigmentation and hyperpigmentation rate of 0.5% (95% CI 0.0-2.5%, I2 = 26%) and 0.4% (95% CI 0.0-2.5%, I2 = 0%). To draw a conclusion, the laser treatment could reach an overall clearance rate of 50% for 75% of the patients with CALMs, for 43.3% of the patients, the clearance rate could reach 75%. When looking at different wavelength subgroups, QS-1064-nm Nd:YAG laser exhibited the best treatment capability. Laser of all the wavelength subgroups presented acceptable safety regarding of the low occurrence of side effects, namely, hypopigmentation and hyperpigmentation.

Efficacy and safety of ablative CO2 fractional laser and narrowband intense pulsed light for the treatment of hypertrophic scars: a prospective, randomized controlled trial.

BACKGROUND AND OBJECTIVES: Hypertrophic scarring is a complex process, and numerous methods have been introduced to treat scars. This study aims to evaluate the effect of combined CO2 fractional laser and narrowband intense pulsed light (IPL) compared to IPL alone in the treatment of hypertrophic scars. MATERIALS AND METHODS: This was a prospective, randomized controlled study enrolled 138 patients with hypertrophic scars. The participants were randomly divided into two groups: CO2-IPL and IPL group, and received three sessions at 10-14-week intervals for 3-month follow-up. Two independent plastic surgeons evaluated the treatments using the Patient and Observer Scar Assessment Scales (POSAS). Overall satisfaction was evaluated using the Patient Satisfaction Scale (PSS). RESULTS: 101 subjects completed the study. Compared to single IPL, the combination CO2-IPL group showed a significant improvement in itching, color, stiffness, thickness, and irregularity, except for pain, and an enhancement in vascularization, pigmentation, thickness, relief, and pliability of the scar, assessed by POSAS (p < .01). 100% patients in the combination group were satisfied compared to 84% in IPL alone. CONCLUSION: The combination of CO2 fractional laser and narrowband IPL efficiently improved the appearance and profile of hypertrophic scars, offering a comprehensive and reliable approach for scar therapy.

HSPA1A Protects Cells from Thermal Stress by Impeding ESCRT-0-Mediated Autophagic Flux in Epidermal Thermoresistance.

Thermoresistance is a physiological phenomenon relevant to noninvasive laser treatments for skin esthetics and tumor removal, although the underlying mechanism remains elusive. We hypothesized that HSPA1A may regulate autophagy by reducing ESCRT-0 and/or STAM2 levels, which could lead to thermal protection from cell death. In this study, we showed that thermoresistance was induced in mouse epidermal tissue and HaCaT cells by heating at 45 °C for 10 minutes. Moreover, HSPA1A levels were increased in thermoresistant mouse epidermis and HaCaT cells. HSPA1A was highly involved in protecting cells from thermal cytotoxicity, as evidenced by the knockdown or overexpression assays of the HSPA1A gene. In addition, ESCRT-0 and STAM2 levels were dramatically decreased in thermoresistant cells, which was mediated by HSPA1A binding to STAM2, particularly through HSPA1A amino acids 395‒509. Furthermore, the loss of ESCRT-0 and/or STAM2 in response to HSPA1A-STAM2 binding regulated autophagy by impeding autophagosome‒lysosome fusion and abolishing autophagic flux in cellular thermoresistance, significantly reducing thermal cytotoxicity and promoting cell survival. To our knowledge, it is previously unreported that HSPA1A-ESCRT-0 and/or STAM2 modulates heat-induced resistance by inhibiting autophagic flux. In summary, the results of this study demonstrate that the mechanisms of thermoresistance may have clinical relevance for noninvasive or minimally invasive thermal therapeutics.

Clinical efficacy and safety of a focused-radiofrequency device on middle and lower face rejuvenation: a retrospective clinical study.

The aim of the present study was to evaluate the efficacy and safety of a unipolar focused-RF device used to rejuvenate the middle and lower face and to create an assessment system. This retrospective study comprised 52 patients with mild-to-moderate skin laxity and wrinkles who received 1-3 treatments 1 month apart and were followed up for 1-7 months. At baseline and post-treatment, three blinded observers measured facial contour and lines, analyzed VISIA scores, and assessed the results using Alexiades Comprehensive Grading Scale (ACGS) and Global Aesthetic Improvement Scale (GAIS). Significant improvements were observed (P < .05) in facial width (left 5.95%, right 5.66%), nasolabial folds (left 18.98%, right 20.56%), marionette lines (left 18.88%, right 25.80%), and cheek lines (left 3.35%, right 3.05%) and in the scores of wrinkles (15.37%), texture (13.67%), pores (6.48%), and red areas (6.57%) using VISIA. There was an obvious reduction in wrinkles, laxity, erythema/telangiectasia based on ACGS, and 75% improved and 5.8% much improved using GAIS. There was no severe side effect. We suggest that the unipolar focused-RF device is an effective and safe technique for middle and lower face rejuvenation and provides a series of comprehensive assessment methods based on standardized photos using VISIA.

Advances in the treatment of traumatic scars with laser, intense pulsed light, radiofrequency, and ultrasound.

Traumatic scarring is one of the most common complications after soft tissue injury caused by burns and trauma, which affects tens of millions of people worldwide every year. Traumatic scars diminish the quality of life due to disfigurement, symptoms of pain and itch, and restricted motion. The pathogenesis and pathophysiology of traumatic scar remain elusive. The management for traumatic scars is comprised of surgical and non-surgical interventions such as pressure therapy, silicone, corticosteroid, and radiotherapy, which are chosen by clinicians based on the physical examinations of scars. Recently, great progress in treating traumatic scars has been achieved by the development of novel technologies including laser, intense pulsed light (IPL), radiofrequency, and ultrasound. The aim of this review article was to summarize the advances of these technologies for traumatic scars intervention.

Application of 460 nm visible light for the elimination of Candida albicans in vitro and in vivo.

The aim of the present study was to investigate the eradicating effects of 460 nm blue light (BL) on Candida albicans in vitro and in C. albicans­infected skin wounds in a mouse model. In the present study, the antifungal effects of irradiation with BL on C. albicans in vitro and in vivo were investigated. C. albicans colonies and cell numbers were investigated using the spread plate method and flow cytometry respectively following treatment with BL irradiation. In order to determine whether BL can eradicate C. albicans cells within biofilms, an in vitro C. albicans biofilm model was established, and the effect of BL was subsequently investigated using a confocal laser scanning microscope and a Live/Dead staining kit. Furthermore, a mouse skin wound infection model infected with C. albicans was established. Wound healing rates and histological examinations were determined 0, 3, 7, 10 and 14 days post­wounding. The results revealed that C. albicans was eradicated by BL in a dose­dependent manner, with a minimum fluence of 60 J/cm2. Irradiation with BL almost completely eradicated C. albicans when the light fluence was 240 J/cm2. C. albicans inside biofilms was also eradicated and biofilms were destroyed following BL irradiation at 240 J/cm2. In addition, BL was revealed to significantly suppress C. albicans infection in vivo. Irradiation with BL promoted the wound healing of C. albicans infected­skin wounds in a mouse model. In conclusion, the results of the present study demonstrated that 460 nm BL may eradicate planktonic and biofilm C. albicans in vitro, and represents a novel therapeutic strategy for the treatment of C. albicans infections in vivo.

Fractional microplasma radiofrequency technology for non-hypertrophic post-burn scars in Asians: A prospective study of 95 patients.

BACKGROUND: Laser and other energy devices are emerging, minimally invasive treatments for scars. Among the various techniques, fractional microplasma radiofrequency technology (FMRT) has proven to be an effective treatment option for various types of scars and skin conditions such as rhytids, striae distensae, and hyperpigmentation. OBJECTIVE: This prospective clinical trial was designed to evaluate the efficacy and safety of FMRT for treating non-hypertrophic post-burn scars in the Asian population. METHOD: All patients underwent three to five treatment sessions at various intervals of 8-16 weeks. The Patient and Observer Scar Assessment Scales (POSAS) [20] were used to evaluate changes in burn scars pre-and post-FMRT treatment. RESULTS: A total of 95 patients completed the study. The overall response rate was 86.3% (82/95). The total POSAS scores before and after 6 months of treatment were 53.41 ± 6.28 and 46.35 ± 5.30, respectively. There was statistically significant improvement in scar color, thickness, and pliability. There was no improvement in vascularization, pain, or itching. Complications included prolonged post-inflammatory hyperpigmentation, acne eruption, herpes simplex eruption, and abnormal hair growth. No severe adverse events, such as acute skin infection, hypertrophic scarring, or depigmentation, were observed. CONCLUSION: FMRT is an efficacious, safe treatment for non-hypertrophic burn scars in the Asian population. Lasers Surg. Med. 49:563-569, 2017. © 2017 Wiley Periodicals, Inc.

Transplanted endothelial progenitor cells increase neo-vascularisation of rat pre-fabricated flaps.

BACKGROUND: Flap pre-fabrication is dependent on the eventual re-vascularisation of the implanted vascular carrier and the presence of a desirable, donor-skin site. However, insufficient neo-vascularisation and subsequent necrosis is an obstacle for this technique. A recent discovery demonstrated that endothelial progenitor cells (EPCs) augment post-natal neo-vascularisation in ischaemic tissues. As a result, we examined whether transplantation of bone-marrow-derived EPCs (BM-EPCs) increases neo-vascularisation and augments the survival areas of pre-fabricated flap in a rat model. METHODS: Rat bone-marrow-derived mononuclear cells (BM-MNCs) were isolated by density gradient centrifugation and cultured in EGM-2MV. The EPCs derived from BM-MNCs were identified by surface makers such as CD34, KDR, CD133 and double-positive staining with 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine-labelled acetylated low-density lipoprotein (Dil-Ac-LDL) and FITC-labelled Ulex europaeus agglutinin-1 (FITC-UEA-1). Pre-fabricated flaps were created by ligating the right femoral vascular pedicle and implanting it underneath the abdominal flap. Forty-five rats were randomly divided into three equal groups. The implantation site around the pedicle was injected subcutaneously with fluorescence-labelled BM-EPCs in group I (n=15), with vascular endothelium growth factor (VEGF) protein in group II (n=15) and with phosphate-buffered saline (PBS) in control group III. Four weeks after injection, the abdominal island flap was elevated and sutured back. Then, neo-vascularisation and flap viability was evaluated on day 7. The labelled EPCs were examined by fluorescence microscopy. RESULTS: After 7 days of culture, the attached cells were spindle shaped and expressed CD34, KDR and CD133. These cells incorporated DiI-Ac-LDL and bound FITC-UEA-1. Greater augmentation of flap survival (87.26+/-10.13% vs. 66.13+/-9.9% and 55.59+/-13.06%, P<0.001), higher capillary density (38.67+/-9.52 capillaries per mm(2) vs. 25.83+/-6.34 capillaries per mm(2) and 26.5+/-5.61 capillaries per mm(2), P<0.05) and larger vascular territories on the microangiogram were observed in the EPCs-treated group relative to the other two groups. The labelled cells formed new vessel structures and expressed von Willebrand factor (vWF) in the pre-fabricated flap. CONCLUSIONS: Local transplantation of BM-EPCs may be a useful strategy for increasing the survival of pre-fabricated flaps, which is consistent with 'therapeutic vasculogenesis'. EPCs are superior to VEGF in their neo-vascularisation ability.

[Comparison of the effect of local administration of endothelial progenitor cells and VEGF on improving neovascularization in flap prefabrication].

OBJECTIVE: To compare the effect of local administration of endothelial progenitor cells (EPCs) and VECF on improving neovascularization and augmenting the survival areas in a rat model of prefabricated flap. METHODS: Prefabricated flaps were created by ligating the right femoral vascular pedicle and implanting it underneath the abdominal flap. The in vitro cultured EPCs (Group I , n=15) and VEGF protein (Group II , n=15) were injected subcutaneously around the implanted pedicle in experimental groups. PBS was injected in control group (Group Ill , n=15). 4 weeks later, the abdominal island flap based solely on the implanted vessels was elevated and sutured back. Then flap viability and numbers of capillary were evaluated on day 7. RESULTS: There was more statistically significant augmentation of flap survival [(87.26 +/- 10.13) % versus (66.13 +/- 9.9)% and (55.59 +/- 13.06)%, P < 0.001], a higher capillary density (38.67 +/- 9.52 versus 25.83 +/- 6.33 and 26.5 +/- 5.61 capillary/mm2 , P < 0.05) in EPCs group than in the other two groups. CONCLUSIONS: EPCs are superior to VEGF in improving neovascularization during flap prefabrication. Local transplantation of bone marrow-derived EPCs may be a useful strategy for augmentation of the survival areas of prefabricated flaps.