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Biomedical Photonics

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Vol 13, No 1 (2024)
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ORIGINAL ARTICLES

4-15 493
Abstract

After tooth extraction, there can be consequences involving injury to the tissue surrounding the extracted tooth, which may lead to severe problems such as inflammation and infection. The wound healing process comprises inflammation, proliferation, and remodeling phases. Photobiomodulation is a therapy form that utilizes the interaction of a light source with tissue. This interaction can activate an increase in Adenosine Triphosphate (ATP), which subsequently triggers a chain reaction leading to the creation of new blood vessels and an increase in the number of fibroblasts. This study used a red laser light source with a power of 3.32 ± 0.01 mW, delivering a dose of 3.5 J to patients for extraction indications. The parameters observed included Interleukin 1_ (IL-1_), Prostaglandin E2 (PGE2), Human Beta defensin 2 (HBD2), and Gingival Index (GI). The results of testing saliva samples using the enzyme-linked immunosorbent test (ELISA) for the parameters IL-1_, PGE2, and HBD2 show a significant influence between the control and therapy groups. Meanwhile, GI revealed a significant influence of therapy on the wound-healing process. Using the Mann-Whitney U test, on day 1, the p-value was found to be 0.32, indicating no significant deference between the control and therapy groups. However, on the third day after the therapy was administered, the p-value was obtained as 0.01, signifying a significant deference between the control and therapy groups. On day 5, a p-value of 0.034 was obtained, signifying a significant deference between the control and therapy groups. Based on the research results, it can be observed that there is a decrease in the values of IL-1_, PGE2, HBD2, and GI. This indicates that local immune cells, including resident macrophages, are activated by pro-inflammatory mediators released in response to injury, and they play an essential role in accelerating wound healing.

16-27 342
Abstract

The structural integrity of the skin, which acts as a barrier to keep harmful external substances out of the body, is compromised by wounds. The process of wound healing is a multifaceted and ever-changing phenomenon that entails the replacement of bodily tissues or damaged skin. It has been demonstrated that nanoparticles, especially silver nanoparticles, have anti-microbial and anti-inflammatory qualities that encourage cell migration and proliferation. Low level laser therapy has the potential to accelerate wound healing by stimulating cell regeneration after injury, reducing pain, and modulating the immune system. The aim of our study is to evaluate the healing process after treatment with silver nanoparticle and/or low level laser by measuring the serum levels of some pro-inflammatory cytokines (IL1b, IL6, and TNF-α), wound healing rate and histological analysis. Wounds were inflicted into 63 adult male albino mice (Mus musculus) and randomly divided into nine groups (7 per each). Control was left to normal healing. Other groups received a different treatment with laser, silver nanoparticle or both for 21 days. Injured skin was sampled for histopathological examination. Quantitative determination of TNFα, IL1 beta and IL6 were carried out using the sandwich enzyme-linked immunosorbent assay (ELISA) twice (day 2 and day 21). One-way and two-way analysis of variance (ANOVA) was used for statistical analysis. The results showed that the groups treated with silver nanoparticles and / or low-level laser promoted wound healing by reducing pro- inflammatory cytokines (IL1β, IL6 and TNFα) and showed significantly better wound closure with a significant reduction in wound size. At day 2 histopathological changes were very similar in different groups. When silver nanoparticles were applied, either alone or in combination with laser exposure, better granulation tissue and fibrosis also necrosis in the canter of the lesion and high score of re-epithelialization with less inflammation observed gradually till day 21. The results of this study suggested that silver nanoparticles and low-level laser have a wound healing potential, since topical treatment with silver nanoparticles and low-level leasers has effectively improved the wound healing process.

28-38 377
Abstract

Photodynamic therapy is an effective method for treating superficial forms of malignant neoplasms, characterized by a minimal risk of damage to normal tissues. In this study, we presented our experience of treating cancer of the oral mucosa using photodynamic therapy, and analyzed the immediate and long-term results of treatment. 38 patients with squamous cell carcinoma of oral cavity mucosa, with a depth of invasion no more than 7 mm, were included in the study. All patients underwent photodynamic therapy with chlorine e6 based photosensitizer. Photosensitizers were administered intravenously 3 hours before irradiation, at a dosage of 1 mg/kg of the patient’s weight. Photodynamic therapy was performed with the following parameters: P – 1.0 W, Ps – 0.31 W/cm2, E – 300 J/cm2. The area of one irradiation field ranged 1.0-2.0 cm2. Treatment effect was evaluated by RECIST 1.1. Overall survival, cancer-specific survival, and disease-free survival were calculated using Kaplan-Meier curves. Evaluation of adverse events was made by .TCAE 5.0 criteria. At 35 (92.1%) out of 38 cases, complete regression was observed after photodynamic therapy. Among them in 3 out of 35 patients relapse was diagnosed in 11.5 to 43.2 months. The total number of patients who didn’t respond to treatment was 6 (15.8%). Follow-up period was 4.2-87.3 months. (mean 42.9). 34 (89.5%) out of 38 patients are alive, 1 (2.6%) died from progression, and three died from other causes. The 5-year overall survival rate was 82.1%, cancer-specific survival rate was 97.0%, and disease-free survival rate was 81.1%. Among the factors significantly (p < 0.05) influencing relapse-free survival: depth of invasion < 5 mm (p – 0.013) and the presence of leukoplakia (p – 0.007). When assessing cancer-specific survival, factors worsening the prognosis were: age >70 years (p – 0.034) and the presence of leukoplakia (p – 0.007). Photodynamic therapy is an alternative treatment method of oral cancer superficial lesions, in case of proper assessment of primary lesion and in case of possibility of full irradiation of the tumor. Moreover, after using photodynamic therapy, the underlying connective-muscular structures are preserved, which promotes rapid healing with minimal scarring, the functions of the affected organ remain intact, and cosmetic defects do not form.

39-46 360
Abstract

The aim of this study was to analyze the immediate and long-term results of using photodynamic therapy (PDT) in patients with leukoplakia of the oral mucosa. The retrospective study included 223 patients with morphologically verified leukoplakia of the oral mucosa. Patients received treatment at the hyperthermia and photodynamic therapy department from 2013 to 2023. The average age was 51.9±8.9 years. Clinically, 211 patients (94.6%) had a flat form of the disease, 12 patients (5.4%) had a verrucous form. The photosensitizer (PS), based on chlorin e6, was administered intravenously once in doses of 1.7 to 2.5 mg/kg body weight. Irradiation of pathologically changed lesions was carried out 2-2.5 hours after the end of its infusion, using a semiconductor laser device “UPL PDT”, with a wavelength λ=665±5 nm. The laser radiation dose density varied from 25 to 100 J/cm², the power density from 0.07 to 0.32 W/cm², the duration of one irradiation field - from 2 to 13.5 minutes, depending on its linear dimensions. The severity of adverse reactions was assessed on days 1-30 after treatment using the CTCAE 4.03 scale. The immediate results of treatment were assessed up to 3 months after PDT, with morphological confirmation of the response to treatment. No serious adverse reactions were observed during PS infusion and irradiation. No symptoms of dermal phototoxicity were reported. During control examinations, up to 3 months after irradiation in patients with flat and verrucous forms, the frequency of complete regressions was 97.1% (n=205) and 58.3% (n=6) cases, partial regressions - 2,9% (n=7) and 25% (n=3) of cases, respectively. Objective response rates were observed at 100% and 83.3%, respectively. The period of observation of patients varies from 3 to 120 months. (average 66 months). The frequency of disease relapses during this period was 9%. Patients with partial regression and identified relapse were treated with repeated PDT sessions. PDT is a well-tolerated and effective treatment method for patients with leukoplakia of the oral mucosa, which has significant advantages over traditional methods of treating this precancerous pathology. These include minimal toxicity to the normal tissues surrounding the pathological foci due to the selective accumulation of PS in leukoplakia tissues, a slight risk of serious adverse reactions, the possibility of an outpatient session, the possibility of repeated treatment over a large area of damage and good cosmetic results).

LITERATURE REVIEWS

47-55 329
Abstract

Photodynamic therapy (PDT) has shown promise as a modality for the treatment of cervical cancer caused by the human papillomavirus (HPV). This review provides a comprehensive examination of the role of PDT in overcoming the challenges presented by conventional treatments for cervical cancer. Beginning with an overview of the relationship between cervical cancer and HPV infection, the review introduces the principles of PDT, its mechanism of action, and its potential as an innovative treatment strategy. The review highlights preclinical studies in animal models that demonstrate the efficacy of PDT in targeting HPV-infected cervical cells and provide mechanistic insights into its cytotoxic effects. We reviewed clinical studies and case reports highlighting the potential of PDT as an alternative or adjunctive treatment option. Challenges and limitations, including depth of light penetration, photosensitizer specificity, and standardization of protocols, will be discussed in the context of potential side effects and comparison with conventional treatments. Future directions include ongoing research, combination therapies with immunotherapy or targeted agents, advances in photosensitizer development, and personalized approaches. The advancement of PDT promises to change the landscape of HPV-associated cervical cancer treatment by providing a targeted, personalized, and minimally invasive approach.

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ISSN 2413-9432 (Print)