Lasers in Surgery and Medicine最新文献

Objectives: Laser therapy is popular for dermatological treatments due to its precision and effectiveness. Post-treatment, applying topical agents helps the skin recover and improves esthetic outcomes. This study aims to investigate the efficacy of collagen dressings in promoting the repair of ex vivo skin tissue following laser treatment, focusing on barrier repair and collagen regeneration.

Methods: This study utilized Q-switched lasers with wavelengths of 532 and 1064 nm to irradiate ex vivo skin tissue. Following laser treatment, collagen dressings were applied. Three types of dressings were evaluated: Type A (laboratory‑prepared Type I collagen formulation), Type B (a commercial dressing based on Type I collagen), and Type C (a commercial dressing incorporating recombinant Type III collagen). The effects of these dressings on skin barrier recovery were assessed by observing Nile Red penetration and measuring the expression levels of skin barrier-related proteins (pan-Keratin, Filaggrin, and Claudin-1). The collagen regeneration in the laser-treated skin tissue was evaluated using Masson staining, and by analyzing the expression of Collagen I (COL I).

Results: Collagen-based dressings facilitated the recovery of the skin barrier, with Type A and Type B dressings showing effectiveness in early-stage barrier repair. During 120-h culture, collagen dressings inhibited the transient upregulation of MMP‑1 while enhancing COL I expression, particularly with the Type C dressing.

Conclusion: The results indicate that collagen dressings provide therapeutic benefits for post-laser skin recovery. These findings highlight the potential of collagen dressings in enhancing the synergistic effects of laser treatments and skin care, suggesting paths for improved clinical practices.

Objectives: Spongiotic gingival hyperplasia (SGH) is an uncommon benign, non-plaque-induced epithelial proliferation for which optimal management remains undefined. We describe the case of SGH treated by ablative therapy with a high-power diode laser and summarize previously reported laser-treated cases from the literature.

Methods: An 11-year-old boy presented with a bright-red, granular enlargement of the marginal and attached gingiva adjacent to the mandibular left canine and first premolar. Electronic search was performed in PubMed/MEDLINE, Scopus, Embase, Web of Science, and LILACS to identify studies reporting laser management of SGH.

Results: The lesion was irradiated using an indium-gallium-arsenide diode laser (808 nm, continuous-wave mode, 1.5 W, 748 J, 499 s). Postoperative evaluation revealed excellent hemostasis, preservation of gingival contour, and complete clinical healing without recurrence at 4 months. Five articles comprising eight cases were retrieved. Reported modalities included CO₂ and Nd:YAG lasers and photodynamic therapy with a diode laser. All achieved favorable outcomes, with complete or near-complete remission and no recurrence during 5-24 months of follow-up.

Conclusions: This is the first documented case of SGH managed with high-power diode laser ablation, demonstrating both safety and favorable esthetic outcomes, thereby expanding current therapeutic perspectives for this condition.

Objective: Evaluated the antimicrobial efficacy of curcumin-mediated photodynamic inactivation (PDI) against both sensitive and resistant strains of Streptococcus pneumoniae and Streptococcus pyogenes, as well as its potential to enhance antibiotic effects (amoxicillin, ceftriaxone, erythromycin).

Methodology: The minimum inhibitory concentrations of antibiotics A, B, and C were evaluated in S. pneumoniae and S. pyogenes strains using serial microdilution. Additionally, the photodynamic action of curcumin as a photosensitizer was examined in multiwell plates, which were then irradiated with a 450-nm LED. The effect of the combination over time was determined by colony-forming units per milliliter, using the determined subinhibitory parameters of antibiotics and PDI.

Results: PDI alone significantly reduced bacterial viability, achieving over 3-log reductions at optimal conditions (2.5 µM curcumin, 6.4 J/cm²). When combined with antibiotics, PDI markedly enhanced bactericidal activity, particularly with β-lactams, producing up to 2.8 log greater reductions than antibiotics alone. Notably, three consecutive PDI treatments led to substantial MIC reductions, up to 128-fold for S. pyogenes. We identified that the synergistic effect of curcumin-PDI is highly time-dependent, revealing a dynamic susceptibility window that can be exploited for enhanced antibiotic action. These results support curcumin-PDI as both an antimicrobial tool and a sensitizer agent that enhances antibiotic efficacy.

Conclusion: The study highlights that optimal timing of PDI application is key to maximizing its synergistic effects with antibiotics, revealing that PDI is most effective when applied during specific stages of bacterial response to antibiotic stress, potentially redefining adjuvant treatment strategies.

Background: Existing data on basal cell carcinoma (BCC) clearance rates are predominantly derived from histological sampling or retrospective analyses. Prospective evaluations of clinical clearance remain limited. This study prospectively assessed long-term clinical clearance and scar outcomes following treatment of BCC with a 1064 nm Nd:YAG laser.

Methods: A total of 34 BCC lesions were treated using a 1064 nm Nd:YAG laser and evaluated at approximately 6 and 12 months post-treatment. Each follow-up included assessment for clinical evidence of recurrence and scar evaluation using the Patient and Observer Scar Assessment Scale (POSAS; range 6 = normal skin to 60 = severe scarring) which is a standardized scale.

Results: Twenty-two patients with 34 BCC tumors completed the study. Patients selected laser therapy primarily due to concerns regarding surgical downtime, cosmetic considerations, prior surgical burden, or poor surgical candidacy. Clinical recurrence was identified in one tumor at 6 months, with no additional recurrences observed at 12 months.

Conclusions: At 6 months, 97% of tumors (33/34) demonstrated clinical clearance, and all 33 tumors remained free of recurrence at 12 months. Scar outcomes were favorable, with mean POSAS patient and observer scores of 2.96 and 3.8 (on a 10-point scale), respectively. The 1064 nm Nd:YAG laser represents a promising, cosmetically favorable, and minimally invasive therapeutic option for BCC, particularly in patients who are suboptimal surgical candidates or who prefer non-surgical interventions.

Cover micrograph: The cover image is based on the article Decoding the Mechanisms of Pigment Reduction and Skin Rejuvenation Induced by Picosecond Laser: Insights From a Porcine Model by Hao Wang et al., https://doi.org/10.1002/lsm.70084.