-
Archives of Dermatological Research Dec 2023Melasma is a skin dyspigmentation condition that disproportionately affects women, particularly those of Latino, Black, and Asian ethnicities, significantly impacting... (Review)
Review
Melasma is a skin dyspigmentation condition that disproportionately affects women, particularly those of Latino, Black, and Asian ethnicities, significantly impacting their quality of life. Efforts to identify effective treatment options have led to the exploration of picosecond laser technology which utilizes brief pulse durations to break down pigment while minimizing thermal damage to surrounding tissue. The 755-nm alexandrite picosecond laser, currently FDA approved for benign pigmented lesion removal, including melasma, is a promising solution. We aim to assess the efficacy and safety of the 755-nm alexandrite picosecond laser both as a stand-alone treatment for melasma and in combination with topical agents. We conducted a PubMed search using "755-nm picosecond" AND "melasma," "755-nm picosecond" AND "hydroquinone," and "755-nm picosecond" AND "tranexamic acid." English-written studies examining this laser as monotherapy or in combination with the topical agents were included. Those not meeting the criteria or lacking data related to melasma improvement were excluded. Monotherapy with the 755-nm picosecond laser led to a 50-75% improvement in melasma appearance in 40% of participants and a significant reduction in the average Melasma Area and Severity Index (MASI) score (p < 0.001) in all patients of one study. Notably, the use of topical tranexamic acid (TTA) in conjunction with the picosecond laser exhibited the most significant degree of improvement in hemi-MASI scores compared to the laser monotherapy group at one- and three-months post-treatment (p < 0.05). Patient satisfaction was also significantly higher for the combination group (p < 0.05). In contrast, combining hydroquinone (HQ) with the picosecond laser demonstrated no significant difference in outcomes compared to HQ alone, both of which were less effective than TTA with picosecond laser. The combination of the 755-nm picosecond laser with TTA proves promising, outperforming both laser monotherapy and laser with HQ. While monotherapy with the picosecond laser or topical agents is effective, literature favors combination therapy, especially the 755-nm picosecond laser with TTA, for superior benefits and minimal side effects. Ultimately, individualized regimens, considering factors like skin type, should be prioritized, given the heightened risk of postinflammatory hyperpigmentation, especially in skin of color patients.
Topics: Humans; Female; Hydroquinones; Tranexamic Acid; Quality of Life; Melanosis; Hyperpigmentation; Treatment Outcome; Lasers, Solid-State
PubMed: 38151661
DOI: 10.1007/s00403-023-02794-0 -
Biochemistry. Biokhimiia Oct 2023The diversity of the retinal-containing proteins (rhodopsins) in nature is extremely large. Fundamental similarity of the structure and photochemical properties unites... (Review)
Review
The diversity of the retinal-containing proteins (rhodopsins) in nature is extremely large. Fundamental similarity of the structure and photochemical properties unites them into one family. However, there is still a debate about the origin of retinal-containing proteins: divergent or convergent evolution? In this review, based on the results of our own and literature data, a comparative analysis of the similarities and differences in the photoconversion of the rhodopsin of types I and II is carried out. The results of experimental studies of the forward and reverse photoreactions of the bacteriorhodopsin (type I) and visual rhodopsin (type II) rhodopsins in the femto- and picosecond time scale, photo-reversible reaction of the octopus rhodopsin (type II), photovoltaic reactions, as well as quantum chemical calculations of the forward photoreactions of bacteriorhodopsin and visual rhodopsin are presented. The issue of probable convergent evolution of type I and type II rhodopsins is discussed.
Topics: Rhodopsin; Bacteriorhodopsins; Photochemistry
PubMed: 38105022
DOI: 10.1134/S0006297923100097 -
Zhong Nan Da Xue Xue Bao. Yi Xue Ban =... Feb 2024Scars are classified into 5 types: Superficial scars, hypertrophic scars, atrophic scars, depressed scars, and keloid. These types are primarily characterized by... (Review)
Review
Scars are classified into 5 types: Superficial scars, hypertrophic scars, atrophic scars, depressed scars, and keloid. These types are primarily characterized by abnormal production of fibroblasts and collagen, as well as the disorderly arrangement of connective tissue. Laser treatment for scars involves the coordinated activation of various signaling pathways and cytokines. However, the exact pathological mechanism for scar formation remains unclear, leading to a lack of radical treatment. Recently, laser treatment has gained popularity as a new minimally invasive approach for scar treatment. The emergence of new theories such as fractional, picosecond laser, and laser-assisted drug delivery has led to continuous advance in laser treatment. Up to now, it has been developed numerous novel treatments, including combined with drug, physical, and other treatments, which have shown superior therapeutic effects. In order to optimize laser treatment in the future, it is crucial to combine new materials with postoperative care. This will help clinicians develop more comprehensive treatment strategies. Therefore, it is important to explore treatment options that have broader applicability.
Topics: Humans; Cicatrix; Laser Therapy; Keloid; Cicatrix, Hypertrophic
PubMed: 38755716
DOI: 10.11817/j.issn.1672-7347.2024.230454 -
Analytical Chemistry Dec 2023Shortening the laser pulse length opens up new opportunities for laser desorption (LD) of molecules, with benefits for mass spectrometry (MS) sampling and ionization....
Shortening the laser pulse length opens up new opportunities for laser desorption (LD) of molecules, with benefits for mass spectrometry (MS) sampling and ionization. The capability to ablate any material without the need for an absorbing matrix and the decrease of thermal damage and molecular fragmentation has promoted various applications with very different parameters and postionization techniques. However, the key issues of the optimum laser pulse length and intensity to achieve efficient and gentle desorption of molecules for postionization in MS are not resolved, although these parameters determine the costs and complexity of the required laser system. Here, we address this research gap with a systematic study on the effect of the pulse length on the LD of molecules. Keeping all other optical and ionization parameters constant, we directly compared the pulses in the femtosecond, picosecond, and nanosecond range with respect to LD-induced fragmentation and desorption efficiency. To represent real-world applications, we investigated the LD of over-the-counter medicaments naproxen and ibuprofen directly from tablets as well as the LD of retene and ship emission aerosols from a quartz filter. With our study design, we excluded interfering effects on fragmentation and LD efficiency from, for example, collisional cooling or postionization by performing the experiments in vacuum with resonance-enhanced multiphoton ionization as the postionization technique. Regarding LD-induced fragmentation, we already found benefits for the picosecond pulses. However, the efficiency of LD was found to continuously increase with decreasing pulse length, pointing to the application potential of ultrashort pulses in trace analytics. Because many interfering effects beyond the LD pulse length could be excluded in the experiment, our results may be directly transferable to the LD applied in other techniques.
PubMed: 38086534
DOI: 10.1021/acs.analchem.3c03558 -
Materials Horizons Oct 2023Here, we describe water-soluble superstructures of hydrophobic nanocrystals that have been developed in recent years. We will also report on some of their properties... (Review)
Review
Here, we describe water-soluble superstructures of hydrophobic nanocrystals that have been developed in recent years. We will also report on some of their properties which are still in their infancy. One of these structures, called "cluster structures", consists of hydrophobic 3D superlattices of Co or Au nanocrystals, covered with organic molecules acting like parachutes. The magnetic properties of Co "cluster structures" a retained when the superstructures is dispersed in aqueous solution. With Au "cluster structures", the longer wavelength optical scattered spectra are very broad and red-shifted, while at shorter wavelengths the localized surface plasmonic resonance of the scattered nanocrystals is retained. Moreover, the maximum of the long-wavelength signal spectra is linearly dependent on the increase in assembly size. The second superstructure was based on liquid-liquid instabilities favoring the formation of FeO nanocrystal shells (colloidosomes) filled or unfilled with Au 3D superlattices and also spherical solid crystal structures are called supraballs. Colloidosomes and supraballs in contact with cancer cells increase the density of nanocrystals in lysosomes and near the lysosomal membrane. Importantly, the structure of their organization is maintained in lysosomes for up to 8 days after internalization, while the initially dispersed hydrophilic nanocrystals are randomly aggregated. These two structures act as nanoheaters. Indeed, due to the dilution of the metallic phase, the penetration depth of visible light is much greater than that of homogeneous metallic nanoparticles of similar size. This allows for a high average heat load overall. Thus, the organic matrix acts as an internal reservoir for efficient energy accumulation within a few hundred picoseconds. A similar behavior was observed with colloidosomes, supraballs and "egg" structures, making these superstructures universal nanoheaters, and the same behavior is not observed when they are not dispersed in water (dried and deposited on a substrate). Note that colloidosomes and supraballs trigger local photothermal damage inaccessible to isolated nanocrystals and not predicted by global temperature measurements.
PubMed: 37740284
DOI: 10.1039/d3mh00949a -
Journal of Cosmetic Dermatology Nov 2023Melasma is a prevalent, persistent hyperpigmentation disorder that negatively affects the psychological health of patients. However, the treatment outcome remains... (Review)
Review
BACKGROUND
Melasma is a prevalent, persistent hyperpigmentation disorder that negatively affects the psychological health of patients. However, the treatment outcome remains unsatisfactory due to the complexity of pathogenesis, recurrence characteristics, and relatively high morbidity.
OBJECTIVES
To compare the performance of laser-related therapies in improving the melasma area severity index (MASI) score of melasma and the occurrence of adverse effects by network meta-analysis (NMA).
METHODS
From the inception to November 2022, eligible randomized controlled trials were identified. Two investigators independently searched relevant studies from PUBMED, EMBASE, and the Cochrane Library database.
RESULTS
A total of 39 clinical studies with 1394 participants were eligible for enrollment. For efficacy, the NMA demonstrated that Q-switched Nd: YAG laser + topical medications (QSND+TM) was superior to Q-switched Nd:YAG laser (QSND) [MD = -4.21 (-6.80, -1.63)], Er: YAG laser + topical medications (ERYL+TM) [MD = -3.52 (-6.84, -0.19)], and picosecond laser + topical medications (PICO+TM) [MD = -4.80 (-9.33, -0.27)]. The microneedling + topical medications (MN+TM) was superior to picosecond laser (PICO) [MD = -5.26 (-10.44, -0.08)] and topical medications (TM) [MD = -5.22 (-9.20, -1.23)]. The top five of the surface under the cumulative ranking curve value (SUCRA) are Q-switched Nd:YAG laser + topical medications (QSND+TM 85.9%), oral tranexamic acid (oTA 80.1%), microneedling + topical medications (MN+TM 79.7%), Q-switched Nd:YAG laser + intense pulse light (QSND+IPL 78.9%), and fractional carbon dioxide laser + topical medications (FCDL+TM 70.5%).
CONCLUSIONS
In conclusion, the Qs-Nd:YAG laser with topical medications is the first choice for treating melasma according to the SUCRA value. Among the three treatment modalities, namely MN + TM, PICO, and TM, our recommendation favors MN+TM as the superior choice for enhancing the curative efficacy in melasma. However, the actual clinical choice should also take into account the adverse effects, the skin type of the patient, the duration of the disease, and other relevant factors.
PubMed: 37737021
DOI: 10.1111/jocd.16006 -
Photobiomodulation, Photomedicine, and... Dec 2023Melasma results from the imbalance of the mechanisms that regulate skin pigmentation, causing the appearance of hyperpigmented patches. Treatment includes topical and... (Review)
Review
Melasma results from the imbalance of the mechanisms that regulate skin pigmentation, causing the appearance of hyperpigmented patches. Treatment includes topical and oral agents, chemical peelings, microneedling, and laser therapy. The picosecond laser was developed to minimize pain and skin discoloration, which can sometimes be associated with laser treatments. It emits short pulses of energy that last from 300 to 500 picoseconds, leading to a more significant fragmentation of melanin, with miniminal risk of scarring and thermal lesions in the surrounding skin. The authors aimed to review the use of picosecond laser in the treatment of melasma and further provide an overview of the other current available options. While the use of picosecond laser for the treatment of melasma has yielded good results, further studies with longer follow-up periods and a higher number of patients are needed.
Topics: Humans; Lasers, Solid-State; Melanosis; Skin; Laser Therapy; Low-Level Light Therapy
PubMed: 38085187
DOI: 10.1089/photob.2023.0096 -
Nature Photonics Oct 2023Bioimaging harnessing optical contrasts and chemical specificity is of vital importance in probing complex biology. Vibrational spectroscopy based on mid-infrared...
Bioimaging harnessing optical contrasts and chemical specificity is of vital importance in probing complex biology. Vibrational spectroscopy based on mid-infrared (mid-IR) excitation can reveal rich chemical information about molecular distributions. However, its full potential for bioimaging is hindered by the achievable sensitivity. Here, we report bond selective fluorescence-detected infrared-excited (BonFIRE) spectral microscopy. BonFIRE employs two-photon excitation in the mid-IR and near-IR to upconvert vibrational excitations to electronic states for fluorescence detection, thus encoding vibrational information into fluorescence. The system utilizes tuneable narrowband picosecond pulses to ensure high sensitivity, biocompatibility, and robustness for bond-selective biological interrogations over a wide spectrum of reporter molecules. We demonstrate BonFIRE spectral imaging in both fingerprint and cell-silent spectroscopic windows with single-molecule sensitivity for common fluorescent dyes. We then demonstrate BonFIRE imaging on various intracellular targets in fixed and live cells, neurons, and tissues, with promises for further vibrational multiplexing. For dynamic bioanalysis in living systems, we implement a high-frequency modulation scheme and demonstrate time-lapse BonFIRE microscopy of live HeLa cells. We expect BonFIRE to expand the bioimaging toolbox by providing a new level of bond-specific vibrational information and facilitate functional imaging and sensing for biological investigations.
PubMed: 38162388
DOI: 10.1038/s41566-023-01243-8 -
Lasers in Medical Science Nov 2023We aim to discuss the use of laser for the treatment of eyebrow microblading and cosmetic tattoo complications through a review of the literature. Our research question... (Review)
Review
We aim to discuss the use of laser for the treatment of eyebrow microblading and cosmetic tattoo complications through a review of the literature. Our research question is whether quality-switched or picosecond laser is superior for the removal of eyebrow tattoos. This structured review was conducted using a PubMed search using the search terms "laser tattoo removal" AND "cosmetic tattoo" AND "eyebrow" with the article type filtered to "case reports," "clinical trial," and "randomized controlled trial" ranging from dates 1994-2023. All case reports or series evaluating the effect of laser on eyebrow cosmetic tattooing pigment were included. We summarize the results of 11 studies evaluating the use of laser for cosmetic tattoo removal, with 129 patients treated specifically for eyebrow pigment. Most studies (8/11) report Fitzpatrick skin type or race. Seven studies utilize quality-switched (QS) neodymium-doped yttrium aluminum garnet (Nd:YAG), alexandrite or ruby, three used picosecond (PS) Nd:YAG or alexandrite, and three used carbon dioxide (CO) laser. We report laser energy, spot size, and pulse duration, as well as treatment outcomes and adverse events. Historically, methods of pigment removal included dermabrasion, cryosurgery, electrosurgery, radiofrequency, infrared light, intense pulsed light, and surgical excision; however, these methods often led to poor cosmetic outcomes including scarring and further dyspigmentation. QS laser treatments provided superior cosmetic outcomes and thus were considered the gold standard treatment option for pigment removal. However, the advent of PS lasers has challenged this given their increased selectivity, lower fluence requirements, and reduction in surrounding thermal damage. Our review demonstrates that PS Nd:YAG is quicker and more effective that QS Nd:YAG in the treatment of eyebrow tattoos. Additionally, the paradoxical darkening seen with QS lasers is less common with PS lasers. We also demonstrate that CO laser may be a helpful adjunct to QS or PS laser. This review focuses on Fitzpatrick skin type and race, providing a unique perspective on the use of laser treatment in skin of color, which often poses an additional treatment challenge.
Topics: Humans; Tattooing; Eyebrows; Carbon Dioxide; Laser Therapy; Lasers, Gas; Lasers, Solid-State; Randomized Controlled Trials as Topic
PubMed: 37932517
DOI: 10.1007/s10103-023-03921-z