Page 30 - ITPS-8-2

INNOSC Theranostics and
Pharmacological Sciences The biochemical and biophysical guide for photodynamic therapy

61 patients with the condition, who were randomly Meanwhile, de Moraes et al. 27 explored
assigned to appropriate treatment groups. One group histomorphological changes and immunodetection
received PDT, whereas the other, the control group, following PDT using chloroaluminum phthalocyanine
was treated with cryotherapy. Several parameters were (AlClPc). The study involved eight participants who were
evaluated during the treatment: the assessment of skin scheduled for tooth extraction. Seven days before the
lesions, pain levels, relapse rates, and side effects. Both extraction, 40 µL of AlClPc nanoemulsion was injected into
groups showed improvement in skin lesions, but the PDT their gums, followed by radiation exposure. The opposite
group demonstrated a slightly higher improvement (13.39 side was used as the control. Tissue samples were collected
± 3.88% before treatment to 1.48 ± 2.50% after the final 7 days after exposure and analyzed. The results showed
treatment). After 3 months of therapy, the recurrence edema in the treated tissues. No side effects were reported,
rate was significantly lower in the PDT group, whereas and the therapy was well tolerated. These findings indicate
cryotherapy showed a recurrence rate of 20 – 53%. The that AlClPc is safe for clinical use in gingival tissue.
study concluded that PDT had a more positive effect on Evangelou et al. investigated the effect of PDT
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the recurrence rate of multiple plantar warts compared to on leukocyte migration following clinical treatment
the traditional cryotherapy method. of basal cell carcinoma. The lesions were treated with
Meanwhile, Theodoraki et al. examined the methylaminolevulinate (MAL), and samples were
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effectiveness of PDT in treating head and neck squamous collected before and after treatment. The study found that
cell carcinoma (HNSCC). For an anti-tumor response to MAL caused rapid infiltration of neutrophils after PDT. In
occur, PDT must trigger a local inflammatory reaction addition, a decrease in the number of Langerhans cells was
within the tumor cells. This study involved nine patients observed just 1 h after PDT. The decrease in Langerhans
with HNSCC. Blood samples were collected before, during, cells could potentially impair the antitumor response,
and after PDT to assess the effects on the immune system. suggesting the need for further research in this area.
The frequency and number of T and B lymphocytes, Finally, a study explored the use of PDT in the treatment
CD4+CD39+ T regulatory cells (Tregs), and natural of periodontitis. The clinical material used was gingival
killer (NK) cells were evaluated using flow cytometry. fluid. Two groups were studied: One group received scaling
The results showed an increase in the number of Tregs and root planning alone, whereas the other group received
and NK cells in patients treated with PDT. In addition, PDT with a 638-nm laser and toluidine blue. Bleeding was
serum concentrations of IL-6 and IL-10 were elevated, assessed over a 3-month period, and a mouth rinse test was
whereas the level of perforin decreased. Despite being a performed to evaluate the level of polymorphonuclear cells.
topical therapy, PDT produced a systemic response. The Improvements were observed in all outcomes compared
increased number of immune cells observed supports the to baseline, with the only significant difference noted in
effectiveness of PDT in HNSCC patients. TNF-α. The study concluded that a single PDT exposure

Immunosuppression may reduce the effectiveness of did not produce significant results in the treatment of
PDT. Niacinamide, that is, Vitamin B3, has been shown periodontitis. 29
to prevent immunosuppression caused by UV radiation.
However, the cause of immunosuppression during PDT is 6. Discussion of commonly used PSs in PDT
not well understood. Therefore, Thanos et al. investigated Porphyrins are a group of organic chemical compounds
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the effect of niacinamide on immunosuppression induced that contain a porphyrin ring. These compounds are
by PDT. The study involved 22 healthy participants who activated by light in the wavelength range of 600 to 700 nm.
tested positive in a Mantoux test. The second group The porphyrin ring consists of four (five-membered) rings
received niacinamide orally at a dose of 500 mg, or a connected by methine bridges (–CH=), forming a planar
placebo, once daily for one week. Specific sites were then structure. The central metal ion, typically a magnesium
irradiated to assess immunosuppression at both irradiated ion, is coordinated with the ring and plays a key role in
and control sites. The study reported that PDT with the many of the biological functions of porphyrins. The most
vehicle or placebo caused significant immunosuppression, well-known porphyrin is heme, a key component of
whereas oral niacinamide therapy reduced it. Contrarily, hemoglobin, which is responsible for transporting oxygen
low-frequency PDT did not induce immunosuppression in in the blood. Other porphyrins are involved in various
patients treated with topical niacinamide. The conclusion biological processes, such as cellular respiration, electron
was that niacinamide could potentially prevent PDT- transport in mitochondria, and metabolism. One example
induced immunosuppression as a low-cost, effective of a porphyrin-based PS is HDP, which is used in PDT.
method. When exposed to light, HDP undergoes a photodynamic

Volume 8 Issue 2 (2025) 24 doi: 10.36922/itps.4559