Lasers in Medical Science最新文献

Adipose-derived mesenchymal stem cells (ADMSCs) possess the ability to transform into various cell types, including neurons. It has been proposed that the optimization of this transformation can be achieved by using photobiomodulation (PBM). The objective of this laboratory-based investigation was to induce the transformation of immortalized ADMSCs (iADMSCs) into neurons with chemical triggers and then evaluate the supportive effects of PBM at two different wavelengths, 525 nm and 825 nm, each administered at a dose of 5 J/cm², as well as the combined application of these wavelengths. The results revealed that the treated cells retained their stem cell characteristics, although the cells exposed to the green laser exhibited a reduction in the CD44 marker. Furthermore, early, and late neuronal markers were identified using flow cytometry analysis. The biochemical analysis included the assessment of cell morphology, viability, cell proliferation, potential cytotoxicity, and the generation of reactive oxygen species (ROS). The findings of this study indicate that PBM does not harm the differentiation process and may even enhance it, but it necessitates a longer incubation period in the induction medium. These research findings contribute to the validation of stem cell technology for potential applications in in vivo, pre-clinical, and clinical research environments.

The research on actinobacteria isolated from traditional medicinal plants is limited. Here, four new Streptomyces isolates (Ha1, Pp1, UzK and UzM) were obtained from the rhizospheres of Helianthus annuus, Pongamia pinnata and Ziziphus mauritiana, frequently utilized in Indian traditional medicine. The Streptomyces isolates aqueous extracts were studied alone against the growth of the Cryptococcus neoformans H99 reference strain, the fluconazole-tolerant T1-5796 and 89-610 strains, three histone deacetylase (HDAC) genes mutant strains, C. gattii NIH198, Candida albicans, C. glabrata, C. parapsilosis and C. tropicalis to determine minimum inhibitory concentration (MIC). Next, the extracts were employed in combination with aluminium-phthalocyanine chloride nanoemulsion-mediated photodynamic therapy to evaluate a possible interaction. We demonstrated that the C. neoformans T1-5796 fluconazole-tolerant strain was more severely inhibited by the Pp1 isolate extract (MIC: 6 mg mL^-1) than H99, which was not inhibited. Growth inhibition of the HDAC null mutants was more prominent for the extract of the UzM isolate, showing inhibition at 2 mg mL^-1. The UzM extract was also the most effective in hindering the Candida species proliferation, with MIC values ranging from 10 to 40 mg mL^-1. The four Streptomyces extracts, especially UzK and UzM, significantly enhanced the antifungal effect of the photodynamic therapy. Our results indicate these Streptomyces isolates as sources of novel metabolites which could potentiate the effect of photodynamic therapy in controlling yeasts superficial infections.

Photodynamic therapy (PDT) is a promising cancer treatment approach. Indocyanine green (ICG) is a water-soluble tricarbocyanine dye with a peak absorption wavelength of around 800 nm and possesses the capacity to produce reactive oxygen species. FTIR spectroscopy is rarely used and offers insights into molecular changes in cancer studies. MCF-7 cells were injected into Nude mouse. Once the tumor had grown to a size of 3-4 mm, mice were randomized into the 12 PDT groups. After each mouse received 5 mg/kg of ICG, they were photo-irradiated with a diode laser emitting light at 809 nm, followed by waiting intervals of 0, 30, 60, and 90 min. Laser irradiation parameters were 150, 250, 500 mW/cm2 and irradiation duration was 1200s. The tumor size was measured every day for four days. The FTIR spectroscopy was used to perform spectral analysis on tumor tissue samples. Four distinct regions (3600-2800 cm-1, 1750-1550 cm-1, 1540-1450 cm-1, and 1700-1100 cm-1) were analyzed, and Hierarchical Cluster study was carried out. A decrease in tumor volume was observed with all PDT applications, except, increases in tumor volume was observed at 150mW 90-minute group. PDT administered after 90 min revealed variations in 150mW and 250mW laser powers in the 3600 cm-1-2800 cm-1 range. The 250mW and 500mW applications resulted in a considerable reduction in fibroadenoma and carcinoma tissues, according to an analysis comparing the A1695 / A1635 ratio. It is proposed that the ideal treatments for further investigation have a power output of 250 mW.

Assessing the responses to the application of photobiomodulation using red and infrared spectrum light-emitting diodes (LED) on diabetic foot ulcers. Diabetic volunteers, of both genders, aged between 30 and 65 years, with grade I or II ulcers, were randomized into the groups: red LED, infrared LED, LED associated, and control. Home-based interventions took place on a daily basis for 12 weeks. Assessments of sample characterization were performed on day 1 and 90, and the variables wound healing index, mean skin temperature, sensitivity and pain in the wound area were measured at the pre-intervention time on days 1, 30, 60 and 90, with subsequent follow-up 30 days after the end of treatment. For statistical analysis, the software SPSS, version 17.0, intention-to-treat analysis, data normality was tested, and the linear mixed effects model, with a significance level of 5%. Magnitudes of clinical effect by Cohen's d. At the pre vs post intervention time of 90 days, we found a large clinical effect of G-LED V (d=1.7) and G -LED IV (d=1.6) in relation to G-C, where these intervention groups showed a tendency for faster wound healing compared to G-C. We also observed small clinical effect of G-LED IV, which showed greater reduction in the area in relation to G-LED V (d=0.4) and G-LED A (d=0.3). Conclusion: The use of individually applied red and infrared LED phototherapy clinically tended to be more effective for the reduction of diabetic foot ulcer areas, and infrared LED was the most effective. Trial registration: NCT03250533 (clinicaltrials.gov).

Hair loss is a prevalent issue worldwide, which, though not life-threatening, can result in psychological problems, low self-esteem, and social anxiety. Previous studies have shown that ultraviolet radiation can have negative effects on hair follicle cells, leading to hair loss, while the impact of blue light on hair and hair follicle has largely been overlooked. This study aimed to examine the effects of blue light on hair follicle stem cells (HFSCs) and primary dermal papilla cells (DPCs), which are essential components of hair follicles. Human HFSCs and primary DPCs were exposed to blue light (457 nm) at various intensities (1, 4, 8, and 16 mW/cm²) for 3 days. Subsequently, cell viability, cell proliferation, and intracellular reactive oxygen species (ROS) were assessed. The results showed that blue light (457 nm) significantly reduced the cell viability and proliferation of HFSCs and DPCs in vitro, with the inhibition being intensity-dependent. Additionally, blue light triggered the overproduction of ROS in the DPCs. While the exact mechanisms by which blue light affects hair follicle cells remain unclear, these findings suggest that blue light could impede the growth of these cells. This insight may offer a new approach to protecting hair by avoiding exposure to high-intensity blue light.

This study aimed to evaluate the dose-dependent brain temperature effects of transcranial photobiomodulation (t-PBM). Thirty adult subjects with major depressive disorder were randomized to three t-PBM sessions with different doses (low: 50 mW/cm², medium: 300 mW/cm², high: 850 mW/cm²) and a sham treatment. The low and medium doses were administered in continuous wave mode, while the high dose was administered in pulsed wave mode. A 3T MRI scanner was used to perform proton magnetic resonance spectroscopy (¹H-MRS). A voxel with a volume of 30 × 30 × 15 mm³ was placed on the left prefrontal region. Brain temperature (°C) was derived by analyzing ¹H-MRS spectrum chemical shift differences between the water (~ 4.7 ppm) and N-acetyl aspartate (NAA) (~ 2.01 ppm) peaks. After quality control of the data, the following group numbers were available for both pre- and post-temperature estimations: sham (n = 10), low (n = 11), medium (n = 10), and high (n = 8). We did not detect significant temperature differences for any t-PBM-active or sham groups post-irradiation (p-value range = 0.105 and 0.781). We also tested for potential differences in the pre-post variability of brain temperature in each group. As for t-PBM active groups, the lowest fluctuation (variance) was observed for the medium dose (σ² = 0.29), followed by the low dose (σ² = 0.47), and the highest fluctuation was for the high dose (σ² = 0.67). t-PBM sham condition showed the overall lowest fluctuation (σ² = 0.11). Our ¹H-MRS thermometry results showed no significant brain temperature elevations during t-PBM administration.

This study aimed to compare the seven-year refractive outcomes of small incision lenticule extraction (SMILE) and femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) for correction of myopia and myopic astigmatism. This retrospective cohort study included 97 eyes of 53 patients who had undergone SMILE or FS-LASIK for myopia seven years prior. Measured parameters included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and manifest refraction. There were no significant differences between the SMILE and FS-LASIK groups in logMAR UDVA, cylinder, and logMAR CDVA at 7 years postoperatively (P>0.05). However, there were significant differences between the two groups in sphere and spherical equivalent (P=0.035 and P=0.016, respectively). UDVA was better than or equal to 20/20 in 81% of the eyes after SMILE and in 63% after FS-LASIK (P = 0.045). The efficacy indices of the SMILE and FS-LASIK groups were 1.04 ± 0.23 and 0.97 ± 0.23 (P=0.405), and the safety indices were 1.18 ± 0.19 and 1.10 ± 0.17 (P=0.543), respectively. This study demonstrates the good predictivity of both SMILE and FS-LASIK. SMILE could offer superior refractive outcomes than FS-LASIK during a 7-year follow-up in correcting myopia and myopic astigmatism.

Cancer cells have the ability to undergo an unlimited number of cell divisions, which gives them immortality. Thus, the cancer cell can extend the length of its telomeres, allowing these cells to divide unlimitedly and avoid entering the state of senescence or cellular apoptosis. One of the main effects of photobiomodulation (PBM) is the increase in the production of adenosine triphosphate (ATP) and free radicals, mainly reactive oxygen species (ROS). Existent data indicates that high levels of ROS can cause shortening and dysfunctional telomeres. Therefore, a better understanding of the effects induced by PBM on cancer cell telomere maintenance is needed. This work aimed to evaluate the effects of low-power red laser (658 nm) and blue LED (470 nm) on the TRF1 and TRF2 mRNA levels and telomere length in human breast cancer cells. MCF-7 and MDA-MB-231 cells were irradiated with a low-power red laser (69 J cm^-2, 0.77 W/cm^-2) and blue LED (482 J cm^-2, 5.35 W/cm^-2), alone or in combination, and the relative mRNA levels of the genes and telomere length were assessed by quantitative reverse transcription polymerase chain reaction. The results suggested that exposure to certain red laser and blue LED fluences decreased the TRF1 and TRF2 mRNA levels in both human breast cancer cells. Telomere length was increased in MCF-7 cells after exposure to red laser and blue LED. However, telomere length in MDA-MB-231 was shortened after exposure to red laser and blue LED at fluences evaluated. Our research suggests that photobiomodulation induced by red laser and low-power blue LED could alter telomere maintenance and length.

Appropriate regeneration of jawbone after dental or surgical procedures relies on the recruitment of osteoprogenitor cells able to differentiate into matrix-producing osteoblasts. In this context, photobiomodulation (PBM) has emerged as promising therapy to improve tissue regeneration and to facilitate wound healing processes. The aim of this study was to determine the effect of PBM on human osteoprogenitor cells isolated from mandibular trabecular bone.Bone marrow stromal cell cultures were established from 4 donors and induced toward osteogenic differentiation for 14 days in a standard osteogenic assay. Cells were irradiated with a combined red/near-infrared (NIR) laser following different schedules and expression of osteogenic, matrix-related, osteoclastogenic and inflammatory genes was analyzed by quantitative PCR.Gene expression analysis revealed no overall effects of PBM on osteogenic differentiation. However, a statistically significant reduction was observed in the transcripts of COL1A1 and MMP13, two important genes involved in the bone matrix homeostasis. Most important, PBM significantly downregulated the expression of RANKL, IL6 and IL1B, three genes that are involved in both osteoclastogenesis and inflammation.In conclusion, PBM with a red/NIR laser did not modulate the osteogenic phenotype of mandibular osteoprogenitors but markedly reduced their expression of matrix-related genes and their pro-osteoclastogenic and pro-inflammatory profile.

Papular acne scars are a special type of acne scar, and the prevalence and treatment of this disease have rarely been reported in the literature; moreover, the prevalence of this disease is often neglected, and treatment is difficult. Our study revealed a high prevalence of this type of acne scar in the clinic and explored an effective and safe method. This retrospective study aimed to analyse the prevalence of papular acne scarring among patients attending our Dermatology Laser Clinic and evaluate the clinical efficacy of fractional CO2 lasers. We retrieved the data of 370 patients with acne scarring who visited our hospital between April 2021 and November 2022 and analysed the prevalence of papillary acne scarring among them. Among these patients, 35 underwent CO₂ laser treatment using an artificial grid pattern. A total of three treatments were administered, with a two-month interval between each session. Scar assessment was conducted using the Global Scar Scale (GSS) and the Acne Scar Clinical Assessment (ECCA) scale, along with physician visual evaluation and patient satisfaction surveys, both before the first treatment and one month after the final treatment. Adverse reactions were recorded during follow-up visits after each treatment. Among the 370 patients with acne scarring, 128 exhibited papular acne scarring, resulting in a prevalence rate of 34.6%. Among them, 37.5% were male and 32.6% were female. A total of 90.6% of patients had combined other types of acne scarring, while 9.4% had papular acne scarring exclusively. Following CO₂ laser grid treatment, there was a significant reduction in GSS scores and ECCA values, accompanied by a noticeable improvement in physician visual evaluation and patient satisfaction scores. Papular acne scarring has a relatively high incidence rate, and there is no significant sex difference. It often coexists with other types of acne scarring. CO₂ laser treatment using an artificial grid pattern effectively improved papular acne scarring with a good safety profile.