Picosecond Laser: Tattoos and Skin Rejuvenation

Evaluation of 755-nm Picosecond Alexandrite Laser With a Focus Lens Array for the Treatment of Enlarged Facial Pores

OBJECTIVES

This study aims to evaluate the use of 755-nm picosecond alexandrite laser with a focus lens array to treat facial pores.

METHODS

Laser treatment was performed on 129 patients between January 2021 and October 2022. VISIA imaging system was used for photographic assessments, the total average number and pore index was calculated, the physicians' assessment score and patient satisfaction score were collected, and the incidence of disadvantage effects was also documented.

RESULTS

The mean patient age was 35.2±6.4 years (21-45 y). The total average number of facial pores was 1614.1±412.8, and the total average number decreased to 1262.6±356.2 three months after the last treatment. The pretreatment baseline of pore index was 26.1±4.5, while the pore index was 21.3±3.7 three months after the last treatment. The physicians' assessment score was 2.7 on the 0-to-4 scale, and patient satisfaction score was 3.5 on the 1-to-5 scale. There were no adverse events, such as hyperkeratosis, scarring, and hypo-or hyperpigmentation.

CONCLUSIONS

755-nm picosecond alexandrite laser with a focus lens array was safe and effective in the treatment of facial pores with relatively few unanticipated adverse events.

LEVEL OF EVIDENCE

Level IV-observational study without controls.

Advances in the Applications of Extracellular Vesicle for the Treatment of Skin Photoaging: A Comprehensive Review

Skin photoaging is a complex biological process characterized by the accumulation of oxidative damage and structural changes in the skin, resulting from chronic exposure to ultraviolet (UV) radiation. Despite the growing demand for effective treatments, current therapeutic options for skin photoaging remain limited. However, emerging research has highlighted the potential of extracellular vesicles (EVs), including exosomes, micro-vesicles, apoptotic bodies and liposomes, as promising therapeutic agents in skin rejuvenation. EVs are involved in intercellular communication and can deliver bioactive molecules, including proteins, nucleic acids, and lipids, to recipient cells, thereby influencing various cellular processes. This comprehensive review aims to summarize the current research progress in the application of EVs for the treatment of skin photoaging, including their isolation and characterization methods, roles in skin homeostasis, therapeutic potential and clinical applications for skin photoaging. Additionally, challenges and future directions in EVs-based therapies for skin rejuvenation are discussed.

Application of Noise Control Combined with Relaxation Training in Patients with Skin Laser Cosmetology: A Single-center Retrospective Study

Objective

Noise pollution has been listed as one of the three major types of pollution, along with air and water pollution. Hospitals should pay attention to noise control, which is of great importance for the treatment and rehabilitation of patients. This study focuses on the application value of noise control and relaxation training.

Methods

This study retrospectively collected and analyzed the clinical data of 184 patients who underwent skin laser cosmetology in Ningbo Yinzhou No. 2 Hospital from January 2021 to December 2022. Twelve patients who did not meet the criteria were excluded, and the remaining 172 patients were divided based on the type of intervention into the control group (CG, n = 82) and the study group (SG, n = 90). The CG received relaxation training and routine noise management, while the SG received noise control combined with relaxation training. The intervention effect was discussed from the aspects of noise, psychology, and satisfaction.

Results

After the intervention, the SG had overtly lower noise levels and lower scores of anxiety and depression compared to the CG (all P < 0.001). Correlation analysis showed that noise levels were positively correlated with scores of anxiety and depression (r = 0.553, r = 0.592, P < 0.001). The two groups had no significant difference in total satisfaction (P > 0.05).

Conclusion

Noise poses a significant threat to the human body. Strengthening noise control in hospitals is beneficial for patients' recovery. Combining noise control with relaxation training is an intervention method worthy of clinical application. It can improve the hospitalization environment and reduce the noise levels to a great extent, thereby improving the psychological state of patients and enhancing the medical satisfaction.

Comprehensive examination of tattoo removal using a 150 ps Nd:YAG laser in a porcine model

This study aimed to investigate the efficacy of a Nd:YAG laser with a pulse duration of 150 ps at different laser parameters. The effects on multiple-colored tattoos with such ultrashort pulses has not been previously described in the literature. In vivo experiments were conducted on porcine skin to analyze the fragmentation efficiency of five different tattoo colors using different wavelengths, pulse energies, and spot sizes. The results showed that the optimal tattoo clearance to safety ratio for blue, green, red, and yellow tattoos with a 532 nm wavelength was 0.96-2.39 J/cm2. The laser with a wavelength of 1064 nm demonstrated the highest efficacy in eliminating black tattoos, with positive results observed for green and blue pigments at a fluence of 3.02 J/cm2. The study provides valuable insights into the efficacy of laser treatment with 150 ps for removing tattoos of different colors using different laser parameters. This information can help dermatologists and practitioners perform more efficient and effective tattoo removal with fewer side effects.

Microlesion healing dynamics in in vivo porcine skin after treatment with 1064 nm picosecond-domain Nd:YAG laser

The fractionated picosecond laser produces microscopic lesions in the epidermis and dermis due to laser-induced optical breakdown (LIOB). There have been multiple histological reports, but the present literature lacks detailed in vivo studies after treatment with high-power laser systems. Our study aimed to characterize the healing patterns of microlesions induced with 150 ps duration 1064 nm MLA-type picosecond laser. The induced picosecond laser-tissue reactions with pulse energy of 50-250 mJ and different treatment modes were observed in in vivo porcine skin model over 10 days after the laser procedure. A macroscopic evaluation was combined with microscopic histological analysis to observe the healing dynamics of laser-induced microlesions. Superficial, intraepidermal cavitation bubbles were induced using microbeam fluence of 4-20 J/cm² . Skin irritation scores positively correlated with pulse energy and dose. Our findings demonstrate that dose and pulse energy had a direct impact on epidermal thickness and lesions healing dynamics.

Efficacy of a home-used high-intensity focused ultrasound device on wrinkle reduction

BACKGROUND

High-intensity focused ultrasound (HIFU) has been developed for the treatment of skin wrinkles on the face, neck, and body.

OBJECTIVES

This study aimed to evaluate the effects of a home-used HIFU device on wrinkles in mice based on the expression of fibrosis-related genes and proteins.

METHODS

The backs of 20-week-old mice were treated with a home-used HIFU using the following probes: 4 MHz, 1.5 mm focal depth. The treated mice were compared with young mice by histological examination, real-time polymerase chain reaction (PCR), and immunohistochemistry. Histological examination was performed by trichrome staining. Real-time PCR and immunohistochemistry were conducted to determine the expression of collagen types I and III, matrix metalloproteinase (MMP)-1, and tissue inhibitor of metalloproteinase (TIMP)-1.

RESULTS

Dermal thickness was increased after treatment with the home-used HIFU device at 30 and 60 s per day for 1 week or 30 and 60 s per day for 2 weeks on trichrome. Gene and protein expression of collagen types I and III and elastin were increased after treatment with HIFU at all options of 30 and 60 s per day for 1 week or 30 and 60 s per day for 2 weeks. Gene and protein expressions of MMP-1 and TIMP-1 were decreased after treatment with HIFU device at 30 and 60 s per day for 1 week or 30 and 60 s per day for 2 weeks.

CONCLUSION

The home-used HIFU device can be an effective therapeutic modality for skin tightening.

Favorable Effect after Single Treatment Session of 755-nm Picosecond Laser with A Diffractive Optic Lens on Facial Wrinkles and Pore Size in Asians

OBJECTIVES

Laser therapy has become one of the mainstay treatments for improving signs of aging including wrinkles, large pores, and skin pigmentation. However, in patients with pigmented skin, an increase in complications including post-inflammatory hyperpigmentation (PIH) has been noted. The purpose of this study is to investigate not only the safety profile of 755 nm picosecond laser with diffractive lens array (DLA) at approximately 2250 pulses on the face in people with darker skin, but also to evaluate its efficacy in treating wrinkles and pore sizes after one treatment session among different age groups.

METHODS

This single-center, retrospective study enrolled patients between age 22 to 65 with both facial wrinkles and enlarged pore sizes. A total of 46 patients (7 male, 39 female, mean age 43) with Fitzpatrick skin types III and IV were enrolled. Two independent data-blinded dermatologists assessed and scored the improvements of patients' wrinkles and pore sizes using photographs.

RESULTS

After one treatment session, statistically significant improvements were observed in lateral canthal wrinkles (p<0.001) and facial wrinkles (p=0.014). In addition, greater percentage of the patients from the aged group (50-65 years-old) showed clinically significant improvement as compared to the younger group.

CONCLUSIONS

For patients with type III and IV skin, one session of DLA picosecond laser treatment at around 2250 pulses to the face is safe and effective for clinically meaningful improvement of the wrinkles and pore sizes, especially for the patients from 50- to 65-years of age.

Laser vaccine adjuvants: Light-augmented immune responses

Adjuvants are essential for ensuring the efficacy of modern vaccines. Considering frequent local and systemic adverse reactions, research into the development of safer and more effective adjuvants is being actively conducted. In recent years, the novel concept of laser vaccine adjuvants, which use the physical energy of light, has been developed. For long, light has been known to affect the physiological functions in living organisms. Since the development of lasers as stable light sources, laser adjuvants have evolved explosively in multiple ways over recent decades. Future laser adjuvants would have the potential not only to enhance the efficacy of conventional vaccine preparations but also to salvage candidate vaccines abandoned during development because of insufficient immunogenicity or owing to their inability to be combined with conventional adjuvants. Furthermore, the safety and efficacy of non-invasive laser adjuvants make them advantageous for vaccine dose sparing, which would be favorable for the timely and equitable global distribution of vaccines. In this review, we first describe the basics of light-tissue interactions, and then summarize the classification of lasers, the history of laser adjuvants, and the mechanisms by which different lasers elicit an immune response.

Effective Picosecond Nd:YAG laser on seborrheic dermatitis and its mechanism

BACKGROUND

The Picosecond Nd:YAG laser has advantages in skin rejuvenation, which has little damage to surrounding tissues due to the ultra-short pulse width. We perform clinical application of Picosecond Nd:YAG laser's tender skin mode, which could improve the seborrheic dermatitis.

MATERIALS AND METHODS

Sixty-three subjects with facial seborrheic dermatitis are randomized to be control and observation groups. Records regarding skin subjective improvement, skin barrier function-related data, skin microbial status, and dermoscopy detection of the two patient groups before and after treatments are investigated.

RESULTS

Improvements of erythema and scales in observation group are significant compared with controls (p < 0.05). In terms of skin barrier function, there are significant changes regarding transepidermal water loss and epidermal seborrhea content in observation group after the laser treatments. Skin microbial state, pityrosporum furfur, and Demodex significantly decrement in observation group. Microscopical findings of infiltration mode advise that scales and capillary congestion and dilatation are significantly improved in observation group. Compared with controls, epidermal gloss increases, pore fineness improves, and capillary density decreases in the observation group.

CONCLUSIONS

Picosecond Nd:YAG laser could efficiently decrease erythema area and seborrheic dermatitis scales and reduce pruritus incidence. The sebaceous gland secretion of seborrhea and multiplying of epidermal parasitic microbiological are inhibited after laser treatment. Less epidermal seborrhea content and inflammation are induced by parasitic microbiology, which is helpful for skin barrier function and microvascular remodeling.

Comparison of fractionated frequency-doubled 1,064/532 nm picosecond Nd:YAG lasers and non-ablative fractional 1,540 nm Er: glass in the treatment of facial atrophic scars: a randomized, split-face, double-blind trial

Background

Laser treatment of acne scars is common, but quality evidence on its efficacy is still needed. Our study aimed to compare picosecond laser and non-ablative fractional laser’s efficacy and safety in treating acne atrophic scars.

Methods

This was a randomized, split-face double-blind trial recruiting patients with acne atrophic scars. Facial halves were randomly divided and treated with fractionated frequency-doubled 1,064/532 nm picosecond Nd:YAG laser or non-ablative fractional 1,540 nm Er: glass laser. ECCA score (echelle d'evaluation clinique des cicatrices d’acne) and skin flatness measured with a non-invasive phaseshift rapid in vivo measurement of skin (PRIMOS) system were evaluated one month after the last treatment.

Results

Twenty-two Fitzpatrick skin type IV patients were included in this study, with an average age of 29.68 years, an average duration of acne scars of 8.8 years. Picosecond laser impacted all acne scar types (before and after treatment; P=0.000 for all types, P<0.001 for V-type, P=0.002 for U-type, and P=0.021 for M-type) and more pronounced effect on ECCA score than non-ablative laser for V-type and U-type acne scars. After treatment, each treatment site’s height was significantly lower than that before treatment (P=0.041) in the picosecond group but not in the non-ablative group (P=0.785). The reported erythema rate was higher in patients treated with a picosecond laser, while edema, exudation, purpura, pain, and long-term AEs were similar between the groups.

Conclusions

Fractionated frequency-doubled 1,064/532 nm Picosecond Nd: YAG laser showed better efficacy in treating acne atrophic scars than the alternative and provided satisfactory safety with added improvement in pores and the glossiness of the skin.

Registration number

ChiCTR2100045982 (comparison of fractionated frequency-doubled 1,064/532 nm picosecond Nd: YAG lasers and nonablative fractional 1,540 nm Er: glass in the treatment of facial atrophic scar: a randomized, split-face, double-blind controlled trial).

The effect of Q-switched 1064-nm dymium-doped yttrium aluminum garnet laser on the skin barrier and collagen synthesis through miR-24-3p

Due to the increase of the world’s population aging, how to restore youthfulness to the skin has attracted much attention. It is well known that collagen synthesis and changes in skin barrier play an important role in the process of skin aging. However, whether Q-switched 1064-nm Nd:YAG laser (1064-QSNYL) determines the involvement of miRNAs in skin collagen synthesis and skin barrier changes remains to be elucidated. Upstream miRNAs of p38 molecular pathway have been predicted by bioinformatic database and the relationship between miRNAs and p38 verified by dual-luciferase reporter gene and Western blotting. RT-qPCR analysis detected the expression of miR-24-3p and mRNA for collagen and skin barrier–related molecules, such as keratin 10 (K10), filaggrin, and Aquaporin 4 (APQ4), in mice back skin and in the keratinocyte cell line HaCaT. Western blotting and immunofluorescence (IF) have been used to detect collagen expression and to localize, as well as quantify K10, filaggrin, and APQ4, respectively. In this study, we show that p38 is the main target gene of miRNA-24-3p, and laser irradiation at 1.5 J/cm² inhibits miR-24-3p expression. Irradiation treatment upregulates the moisture, elasticity, hydroxyproline, and superoxide dismutase content of mice skin, as well as inhibits trans-epidermal water loss. Irradiation also increases collagen, K10, filaggrin, and APQ4 in both mice skin and HaCaT cells. Interestingly, we found that miR-24-3p overexpression inhibits the effect of irradiation on collagen synthesis and skin barrier. We show for the first time that 1064-QSNYL promotes collagen synthesis and protective effects on skin barrier by downregulating miR-24-3p.

Tissue Modification in Nonsurgical Facelift Options

Nonsurgical facelifts are a term for a heterogeneous group of procedures used by physicians to improve facial rejuvenation without the use of operative techniques. Patients demand these services due to the reduced recovery time and generally lower risk. However, nonsurgical techniques, to be effective, must induce conformational change in the cells and tissues of the face. Therefore, these techniques are significant procedures that have associated risks. Understanding the tissue modifications and mechanisms of action of these techniques is vital to their safe and effective use. The purpose of this article is to provide a background of tissue modification in nonsurgical facelift options.