Lasers in Medical Science最新文献

To compare the efficacy and safety of picosecond lasers (PSLs) versus nanosecond lasers (NSLs) for treatment of hyperpigmented disorders and tattoos, we conducted a systematic review of literature. PubMed, Web of Science and Cochrane library (from inception to December 2024) were searched for articles. The primary outcome was the treatment success rate (≥ 75% clearance of pigment), and the secondary outcomes were the visual analogue scale (VAS) to assess pain and the rates of adverse events. We analyzed 20 randomized controlled trials and 1 retrospective comparative study comprising a total of 971 patients. For efficacy, PSLs and NSLs had comparable clearance for endogenous hyperpigmentation (RR 1.06, 95% CI [0.85, 1.31], P = 0.60), but PSLs tend to have superiority (RR 1.39, 95% CI [0.99, 1.94], P = 0.05) for exogenous hyperpigmentation. For pain assessment, the mean value of VAS for PSLs and NSLs was between 1.5 and 5.61 and 1.0 to7.9. Both lasers were tolerable and PSLs led to less pain (P < 0.01). Adverse events including post-inflammatory hyperpigmentation (PIH) and post-inflammatory hypopigmentation (PIHo) were much more obvious in Asian than European patients. Meanwhile, compared with NSLs, PSLs had significantly less rate of PIH (P = 0.02; I² = 28%) and PIHo (P = 0.002; I² = 13%). This systematic review suggests that PSLs had comparable efficacy with NSLs. Regarding safety, the superior profile of PSLs is currently best supported in Asian cohorts; data remain sparse for other phototypes.

Photobiomodulation (PBM) is an emerging therapeutic strategy that uses light to modulate biological processes. In the context of cardiovascular diseases, its benefits include improved circulation, reduced oxidative stress, and tissue regeneration, making it a promising alternative for patients resistant to conventional treatments, such as hypertensive patients. This study highlights pharmacological strategies that can enhance the effects of PBM, such as the association with antioxidants, which neutralize reactive oxygen species (ROS) and protect the cardiovascular system against oxidative stress. In addition, there is evidence that the combination of PBM with coenzyme Q10 reduces inflammation, increases ATP production, and improves vasodilation. Another promising approach involves the use of compounds that block the extrusion or inhibit the degradation of cyclic GMP, an essential messenger for the vasodilatory response. Thus, these combinations can optimize the effects of PBM in cardiovascular diseases. However, further investigation is needed to validate these approaches and explore their clinical impact, enabling more effective and personalized therapies for patients with resistance to conventional treatments.

Background: Tonsillectomy is a common surgical procedure used to treat chronic tonsillitis, obstructive sleep apnoea, recurrent or chronic tonsillitis and Peritonsillar abscesses. Traditional methods like cold steel dissection and electrocautery are effective but often associated with significant bleeding, pain, and prolonged recovery. Carbon dioxide (CO₂) laser-assisted tonsillectomy offers a precise, haemostatic alternative with potential advantages in reducing surgical trauma.

Purpose: This systematic review evaluates the clinical efficacy and safety of CO₂ laser tonsillectomy compared to conventional surgical techniques.

Methods: A comprehensive search of PubMed, Embase, Scopus, and the Cochrane Library was conducted following PRISMA 2020 guidelines. Ten studies comparing CO₂ laser tonsillectomy with traditional approaches were included. Key outcomes assessed were intraoperative blood loss, postoperative pain, operative time, healing, complications, and patient satisfaction.

Results: CO₂ laser tonsillectomy showed reduced intraoperative bleeding and, in many cases, lower postoperative pain and faster recovery. Operative times were sometimes longer, and partial tonsillotomy carried a risk of symptom recurrence. The laser method was especially beneficial for adults and patients unsuitable for general anaesthesia.

Conclusions: CO₂ laser tonsillectomy is a safe and effective alternative to traditional methods, particularly in select patient groups. While it offers advantages in recovery and haemostasis, further research is needed to confirm long-term outcomes and optimize surgical protocols.

Head and neck cancer has a multifactorial etiology and significant cellular heterogeneity, which makes treatment difficult and contributes to high mortality rates. The need to combine different therapeutic modalities, such as surgery, chemotherapy, and radiotherapy, increases patient toxicity and requires a multidisciplinary approach to optimize results and improve quality of life. In recent years, photobiomodulation (PBM) has gained ground in tissue rehabilitation and regeneration. However, its effect on squamous cell carcinoma tumor cells lacks investigation. This study evaluated the effects of PBM on head and neck squamous cell carcinoma (SCC) based on cell proliferation and viability. We explored the behavior of two cell lines, SCC09 and CAL27, under 5 sequential applications of PBM using the Fluence HTM^® device and laser pens of different wavelengths (830 nm and 658 nm) with irradiation doses of 1, 3, and 6 J/cm². To ensure standardization and avoid unwanted reflections, a specific adapter was developed, maintaining a fixed distance of 20 mm between the light source and the cells in culture, on a black surface. Cell viability was measured through the MTT ([3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl tetrazolium bromide]) experiment and proliferation was evaluated through the Sulforhodamine B (SR-B) assay. No significant effects on cell proliferation or viability of the evaluated cell lines were identified. PBM did not demonstrate a significant effect on cell proliferation and viability under the experimental conditions tested. However, the variability found in other studies highlights the need for additional research to elucidate the mechanisms of action of PBM and establish safe treatment protocols.

Breast cancer is one of the most common lethal cancers in the world. Standard diagnostic methods, particularly tissue biopsies, are invasive and often fail to detect tumor heterogeneity, leading to suboptimal treatment outcomes. This study aims to assess and evaluate the potential of photoacoustic imaging (PAI) and photoacoustic spectroscopy (PAS) as noninvasive technologies that replace conventional methods for diagnosing breast cancer with increased depth of tissue penetration, improved resolution, and molecular sensitivity. This meta-analysis introduces the principal advantages and limitations of the PAI and PAS technologies. It applies a statistical approach to assess diagnostic performance, sensitivity, and specificity in preclinical and experimental settings. Data from six relevant studies on PAS for breast cancer screening were summarized. The analysis revealed a pooled sensitivity of 84% and specificity of 96% to assess the diagnostic performance of the PAS/PAI technologies. The estimate of pooled logit-transformed diagnostic performance was 0.72 (95% CI: 0.71-0.72), equivalent to 84% pooled sensitivity and 96% specificity. The logit value reflects variance-stabilized analysis and cannot be interpreted as uncorrected diagnostic accuracy, and the average heterogeneity across studies was moderate (I² = 51.0%). These results highlight the potential of the PAI and PAS as reliable and noninvasive diagnostic instruments with the ability for early detection as well as improved patient outcomes.

This study aimed to assess the effect of the Er:YAG laser, either alone or in combination with topical fluoride application, on the prevention and progression of erosive tooth wear in primary enamel. A total of 120 extracted human primary molars were flattened, polished, and divided based on substrate condition: sound or previously eroded with citric acid. The specimens were allocated into 12 experimental groups and received one of the following treatments: no treatment (control), topical application of acidulated phosphate fluoride (APF 1.23%), irradiation with Er: YAG laser using two different protocols (0.20 W and 0.40 W), or combinations of laser followed by fluoride application. All samples were then subjected to a five-day erosive remineralization cycling protocol, involving repeated acid exposure (pH 2.6) and immersion in artificial saliva. Enamel surface loss was assessed by optical profilometry, and morphological changes were evaluated by environmental scanning electron microscopy. The findings demonstrated that all interventions tested, including laser irradiation, fluoride application, and their combinations, were effective in reducing enamel loss when compared to untreated controls. However, no statistically significant differences were found between the various treatment protocols. The results suggest a promising protective effect of Er: YAG laser and fluoride treatments for preventing and controlling the progression of erosive tooth wear in primary enamel, highlighting the need for further research to confirm their efficacy.

To compare the effects of thulium laser (TmLR) versus low-temperature plasma radiofrequency ablation (COBLATION) on perioperative parameters, serum inflammatory factors, and postoperative healing following tonsillectomy in New Zealand rabbits. Twenty-four rabbits were randomly selected. The left tonsil underwent TmLR, while the right underwent COBLATION. Postoperative wound healing on both sides was compared. Another twenty-four rabbits were randomly divided into two groups, undergoing bilateral tonsillectomy using either TmLR or COBLATION. Surgical duration, intraoperative blood loss, postoperative water intake, weight changes, postoperative inflammatory factor levels, and pathological analysis of the fibrin membrane covering the wound were compared between the two groups. The TmLR group had significantly shorter surgical duration and less intraoperative blood loss than the COBLATION group (P < 0.05). Postoperative water intake was significantly higher in the TmLR group (P < 0.05). Weight loss was significantly less in the TmLR group (P < 0.05). Endoscopic examination at 4 h post-surgery revealed better wound conditions in the TmLR group. However, at postoperative days 1, 3, and 5, the COBLATION side showed better recovery, with statistically significant differences in wound scores (P < 0.05). By postoperative day 7, both sides recovered well with no significant histological differences between groups (P > 0.05). Hematological analysis revealed no statistically significant differences in inflammatory factor levels between the two groups. Pathological analysis indicated a more pronounced inflammatory reaction in the TmLR group at day 3 compared to COBLATION. By day 7, the pathological manifestations were similar in both groups. Thulium laser tonsillectomy offers advantages in terms of shorter surgical time, reduced intraoperative bleeding, and potentially lower postoperative pain (as inferred by higher water intake and less weight loss). There was no statistically significant difference in overall efficacy between the thulium fiber laser system and the low-temperature plasma system. The thulium laser can be considered a viable alternative instrument for tonsillectomy.

Purpose: Multidrug-resistant bacterial infections are a substantial global health challenge. Targeting bacterial virulence factors that control the progression, severity, and pathogenicity of bacterial infections could prevent and combat infection by intractable, potentially life-threatening pathogens such as methicillin-resistant Staphylococcus aureus (MRSA). Laser-based antibacterial photodynamic therapy (aPDT) has emerged as a promising alternative for infection management.

Methods: This study assessed the attenuation of adhesion and invasion of MRSA bacteria in two human epithelial cell lines, melanoma cells (A375) and breast ductal carcinoma (T47D), after exposure to different sublethal femtosecond laser doses. The INSPIRE HF100 laser system (Spectra Physics), pumped by a mode-locked femtosecond Ti: sapphire laser MAI TAI HP (Spectra Physics), was used to provide the femtosecond laser pulses at a wavelength of 400 nm for different durations; 15, 30, and 45 min., as well as different average powers; 50, 100, and 150 mW.

Results: Our results showed that, an average power of 50 mW for 15 min. significantly reduced MRSA adhesion (by ~ 84-96%) and invasion (by ~ 84-98%), even though exposure durations of 30 and 45-min. resulted in reduced viability (p < 0.0001 by ANOVA and Tukey test).

Conclusion: All proposed femtosecond laser doses effectively impaired MRSA's ability to adhere to and invade epithelial cells.

Melasma is a common acquired disorder of disfiguring hyperpigmentation and has attracted increasing attention in the field of medical aesthetics due to its high risk for recurrence and difficulty in treatment. Low-fluence Q-switched Nd: YAG 1064 nm (LFQSNY) laser is a commonly used phototherapy clinical for melasma at present, however, the mechanism underlying the photomanipulation remains unclear. Herein, this study aims to elucidate the potential mechanisms underlying the LFQSNY laser treatment. B16F10 murine melanoma cells were subjected to LFQSNY laser irradiation for evaluating melanin synthesis, tyrosinase activity, and melanogenic gene expression. RNA-seq and dual-luciferase reporter assays were utilized to dissect the interaction of DHX9 with TRIB3. C57BL/6J mice skin were irradiated for further assessments. Additionally, M1-polarized RAW264.7 macrophages were treated by laser to investigate inflammatory-mediator production and phagocytic capacity. LFQSNY laser irradiation significantly attenuated melanin production in cells via upregulating DHX9 and repressing TRIB3 through promoter binding, which emerged as a critical determinant of melanogenesis suppression. Furthermore, LFQSNY laser reduced the inflammatory factors and enhanced the phagocytic activity in macrophages, resulting in the anti-inflammatory activities and pigment-clearing. Our findings reveal that LFQSNY laser inhibits the melanogenesis of melanocytes and enhances the effect of anti-inflammation for improves pigment-clearance in melasma via a non-thermal photobiomodulation. The insights provide a mechanistic rationale for enhancing clinical efficacy of LFQSNY laser-therapy in melasma.