Photodiagnosis and photodynamic therapy最新文献

Background: Photodynamic therapy (PDT) has emerged as a promising approach against bacterial biofilms. However, its efficiency is usually limited under oxygen-deficient conditions such as in Clostridium perfringens infections.

Objective: To design and evaluate an in vitro hybrid hydrogel-nanocarrier antimicrobial photodynamic platform and to determine whether measurable antibacterial, antibiofilm, and anti-α-toxin effects can be maintained against Clostridium perfringens under verified oxygen-limited conditions.

Methods: The hybrid formulation was prepared by combining a sodium alginate-alum hydrogel with Allura Red AC-chitosan nanocarriers. C. perfringens biofilms were treated with a 630 nm diode laser at fluences of 5, 10, 15, and 20 J/cm² under strictly oxygen-limited (hypoxic) conditions verified using a resazurin indicator. Reactive oxygen species (ROS), including singlet oxygen (¹O₂), were quantified using SOSG and HPF probes, while biofilm biomass and viability were assessed via crystal violet, Congo red, and CFU assays. Photoluminescence quantum yield (the ratio of emitted to absorbed photons) was determined using standard spectrofluorometric procedures.

Results: The hybrid system produced measurable ROS even in low-oxygen environments, indicating a shift toward Type I photochemical pathways. Significant biofilm disruption and bacterial inactivation (p < 0.05) were achieved, particularly at 15 J/cm². The hydrogel provided prolonged retention and more uniform illumination, whereas chitosan nanocarriers enhanced dye-bacteria contact and localized ROS delivery. Allura Red served only as a model chromophore to test platform performance under stringent oxygen-limited conditions and is not intended for clinical antimicrobial PDT.

Conclusion: This study demonstrates an in vitro, platform-level proof-of-concept for an oxygen-tolerant antimicrobial photodynamic therapy system under oxygen-limited conditions. Allura Red was used exclusively as a conservative stress-test chromophore and is not proposed as a clinical photosensitizer. The findings indicate that platform design-hydrogel retention and nanocarrier-mediated bacterial contact/targeting-rather than chromophore efficiency alone, plays a central role in sustaining measurable photodynamic activity under oxygen-limited conditions.

Photodynamic Diagnosis (PDD) is a non-invasive imaging technique. It relies on a photosensitizer that, when activated by a specific light source, causes metabolically active tissues like tumors to emit visible red fluorescence. PDD offers high sensitivity, high specificity, and real-time visualization. This article reviews advances in the use of PDD for common cutaneous tumors, including Keratinocyte Carcinoma and extramammary Paget disease (EMPD). In managing skin tumors, PDD can be used during preoperative, intraoperative, and postoperative stages. This helps optimize diagnosis and treatment. Preoperatively, PDD clearly delineates tumor margins and identifies subclinical lesions. It aids in planning surgical or photodynamic therapy-especially for multifocal or ill-defined lesions, such as Bowen's disease and actinic keratosis. Intraoperatively, PDD guides surgeons in determining excision boundaries in real-time. This increases the rate of negative margins (for example, up to 98.6% in cutaneous squamous cell carcinoma surgery) while reducing the number of surgical stages and tissue damage. Postoperatively, PDD can evaluate treatment response, monitor for residual disease, or detect early recurrence. This enables non-invasive, repeatable follow-up. Limitations of PDD include false positives due to inflammation, interference from nonspecific fluorescence, limited depth of fluorescence penetration, and variability in tumor tissue. Looking forward, new technologies such as nanotechnology, artificial intelligence, and multimodal imaging may broaden the use of fluorescence detection in dermatology.

Background: Sleep disturbances are highly prevalent among older adults and associated with substantial morbidity. Although bright light therapy has shown efficacy for insomnia, the evidence supporting near-infrared (NIR) light is comparatively limited.

Aims: To examine the effects of NIR (850 nm photobiomodulation to the neck), white light (WL, to the eyes), and their combination on sleep and melatonin secretion in older adults with insomnia symptoms, and explore whether chronotype moderated treatment outcomes.

Methods: A randomized clinical trial was conducted among 59 community-dwelling adults aged ≥ 60 years with early wakening and sleep-maintenance insomnia symptoms. Participants were randomized to NIR, WL, or NIR+WL for 60 min nightly over two weeks. Data gathered included actigraphy-derived sleep parameters, Pittsburgh Sleep Quality Index (PSQI), salivary melatonin concentration, and dim-light melatonin onset (DLMO). Chronotype was assessed with the Munich Chronotype Questionnaire, and its moderating effect was examined.

Results: PSQI scores improved significantly across all intervention groups, with increases in subjective sleep duration of 0.43 h (WL), 0.81 h (NIR), and 1.08 h (NIR+WL). No significant changes were observed in actigraphy-derived sleep indicators or melatonin measures. Chronotype significantly moderated treatment effects, with late chronotypes demonstrating greater improvement in sleep duration and efficiency with WL, whereas early chronotypes showed greater improvement with NIR+WL.

Conclusions: Both NIR and WL were associated with improvements in subjective sleep quality and duration. Chronotype-specific patterns of response suggest distinct underlying mechanisms and support the potential for personalized light-based interventions for insomnia in older adults.

Clinical trial registration: This study was registered on ClinicalTrials.gov (https://clinicaltrials.gov/study/NCT06292819).

Objective: To evaluate the efficacy of photodynamic therapy (PDT) in treating cervical low-grade squamous intraepithelial lesions (LSIL) and to identify factors influencing treatment outcomes.

Methods: We conducted a retrospective study of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) treatment of 93 women diagnosed with cervical LSIL and concurrent high-risk human papillomavirus (HR-HPV) infection. Follow-up assessments of HPV, cytology and colposcope were performed at 6 and 12 months.

Results: At the 6-month follow-up, pathological regression was observed in 79.8% (71/89) of patients and HR-HPV in clearance 65.2% (58/89). By 12 months the regression rate increased to 85.9% (73/85) and HR-HPV clearance rate to 78.8% (67/85), while one patient experienced disease progression. Analysis indicated that HPV vaccination history was associated with LSIL reversal and HPV clearance at 6 months (P < 0.05).

Conclusion: ALA-PDT is effective and well-tolerated for the treatment of LSIL patients with HR-HPV infection, with outcomes influenced by prior HPV vaccination. The combination of vaccination and PDT may yield synergistic therapeutic benefits for cervical lesions.

Purpose: To investigate the acute effects of short-term exposure to full-spectrum light on ocular biometric parameters in children with intermittent exotropia (IXT) across different refractive states.

Methods: Children with IXT were recruited and categorized into myopia, emmetropia, and hyperopia groups based on their baseline refractive status. All participants underwent a single 4-hour session of exposure to full-spectrum light (illuminance: ≈ 500 lux; correlated color temperature: ≈ 4000 K). Axial length (AL), subfoveal choroidal thickness (SFCT), and crystalline lens thickness (LT) were measured before and after the intervention using optical biometry and optical coherence tomography. Changes in ocular parameters were analyzed using linear mixed models and partial correlation analyzes.

Results: The ocular response to full-spectrum light exhibited significant refractive-state specificity. The myopia group exhibited significant acute axial shortening (ΔAL = -0.008 ± 0.003 mm; p < 0.05) and a negative correlation between axial length and choroidal thickness changes (p = 0.013), in the absence of significant choroidal thickening at the group level. In contrast, emmetropic eyes showed physiological axial elongation with inferior choroidal thickening, while hyperopic eyes maintained structural stability.

Conclusions: Short-term exposure to full-spectrum light induces distinct, refraction-dependent ocular structural responses in children with IXT. While emmetropic eyes maintain normal circadian growth patterns, myopic eyes exhibit acute axial shortening. The dissociation between axial shortening and choroidal thickening in myopic eyes suggests the involvement of alternative posterior segment regulatory mechanisms. These findings suggest good short-term biocompatibility of full-spectrum lighting and provide insight into refraction-dependent light-eye interactions in children with intermittent exotropia; however, longitudinal studies are needed to determine whether these acute effects translate into sustained ocular changes and to assess potential rebound effects.

Purpose: Near-infrared photoimmunotherapy has been approved in Japan for unresectable locally advanced or recurrent head and neck cancer. While this therapy theoretically induces selective necrosis of epidermal growth factor receptor-expressing tumor cells following administration of cetuximab sarotalocan sodium and irradiation with 690-nm light, residual disease is not uncommon in clinical practice. The mechanisms underlying such persistence remain poorly understood.

Methods: We examined two patients with head and neck squamous cell carcinoma who underwent salvage resection due to residual disease after four cycles of near-infrared photoimmunotherapy. Resected specimens were subjected to histopathological evaluation, including immunohistochemistry for epidermal growth factor receptor, cluster of differentiation 8, programmed cell death protein 1, and forkhead box P3 proteins.

Results: In both cases, residual tumor cells were predominantly localized in the superficial mucosal layers, while deeper layers were replaced by fibrosis. All residual tumors retained expression of epidermal growth factor receptor. Lymphocytic infiltration was sparse, with scattered cluster of differentiation 8-positive cells but few programmed cell death protein 1-positive or forkhead box P3-positive lymphocytes. These findings suggest that the tumor microenvironment surrounding residual tumors may have been unfavorable for the induction of robust antitumor immune responses.

Conclusion: Residual tumors after near-infrared photoimmunotherapy can occur despite adequate laser irradiation and epidermal growth factor receptor expression. Our observations imply that insufficient immune activation within the tumor microenvironment may contribute to treatment resistance. Further characterization of the post-photoimmunotherapy tumor microenvironment will be essential to better understand treatment mechanisms and to optimize therapeutic efficacy.

The early symptoms of subungual squamous cell carcinoma are often nonspecific, leading to frequent misdiagnosis as conditions such as paronychia or subungual warts. Treatment options for this malignancy remain relatively limited in clinical practice. This study presents the case of a 74-year-old male with subungual squamous cell carcinoma who achieved significant improvement following photodynamic therapy. The patient had experienced pain and exudation of the big toe for over six months. Initially diagnosed with paronychia, he was treated with oral clarithromycin tablets (0.5g daily) for half a month, which yielded no notable improvement. Subsequent intermittent application of iodophor and mupirocin ointment also resulted in poor clinical outcomes. A pathological biopsy was then performed, leading to a diagnosis of subungual squamous cell carcinoma. The tumor tissues were removed by local resection, followed by three sessions of photodynamic therapy administered at 10-day intervals. All suspected lesions were excised via local resection, with preservation of the nail bed and nail fold. A 20% 5-aminolevulinic acid (ALA) solution (118mg, Shanghai Fudan-Zhangjiang Bio-Pharmaceutical Co., Ltd) was topically applied to the entire nail bed and nail fold, occluded with aluminum foil to block light, and incubated for 3 h. After removal of the covering, the area was irradiated with 635-nm red light at 100 mW/cm² and 120 J/cm² for 20 min (Kernel Medical Equipment Co., Ltd). Prior to treatment, the patient took 200 mg ibuprofen orally for analgesia. During the eight-month follow-up period, no recurrence was observed. It is worth noting that due to the patient's history of severe onychomycosis, some residual fungal nail changes remained visible after recovery.

Purpose: To compare the safety, efficacy and predictability of ray-tracing-guided with Q-value-adjusted laser-assisted in situ keratomileusis (LASIK) for correcting myopic astigmatism of 2.00 Diopters (D) or greater at 3 months postoperatively.

Methods: This retrospective, comparative clinical study included 60 eyes with myopic astigmatism ≥ 2.00 D: 30 eyes in the ray-tracing-guided group (InnovEyes group) and 30 eyes in the Q-value-adjusted group (Custom-Q group). Uncorrected distance visual acuity (UDVA), best-corrected distance visual acuity (CDVA), manifest refraction spherical equivalent (MRSE), sphere and cylinder were evaluated preoperatively and 3-month postoperatively. General estimating equitation was used for inter-group comparison and correlation analyses to account for potential inter-eye correlation within subject.

Results: At 3-month postoperatively, CDVA was better in the InnovEyes group (P = 0.005), with 87% of eyes achieving cylinder within ± 0.25 D (vs. 63% in the Custom-Q group). Vector analysis revealed InnovEyes group induced a slight overcorrection (correction index: 1.04 ± 0.02) versus Custom-Q group's undercorrection (correction index: 0.94 ± 0.02) (P = 0.007), with InnovEyes group exhibiting significantly smaller magnitude of error (0.08 ± 0.04 vs. -0.13 ± 0.05, P = 0.002).Correlation analyses revealed that both correction index and magnitude of error were non-significant correlated with TIA in either group (all P > 0.05). The group × TIA interaction was also non-significant (both P > 0.05).

Conclusions: Ray-tracing-guided LASIK is an effective, safe, and predictable surgical option for eyes with myopic astigmatism ≥ 2.00 D. Although a tendency toward mild astigmatism overcorrection was noted, it achieved statistically better postoperative CDVA and small astigmatic errors compared to the Q-value-adjusted group at 3 months postoperatively.