The Physics of Light and Sound in the Fight Against Skin Cancer

Pratavieira, Sebastião; Requena, Michelle Barreto; Stringasci, Mirian Denise; Ayala, Erika Toneth Ponce; Bagnato, Vanderlei Salvador

doi:10.1007/s13538-022-01121-8

Cited by 6 publications

(10 citation statements)

References 112 publications

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“…sensitizer) and an external energy source capable of activating such a molecule, triggering a series of reactions that lead to the tumor cell's death. 1 Protoporphyrin IX (PpIX) is a well-known endogenous porphyrin employed as a sensitizer in the implementation of some dynamic therapies such as photodynamic and sonodynamic therapy. [2][3][4] PpIX can be enzymatically synthesized and reach concentrations above the physiological levels by the exogenous administration of its precursor, 5-aminolevulinic acid (5-ALA).…”

Section: Introductionmentioning

confidence: 99%

Quantification of protoporphyrin IX in murine pigmented melanoma induced by systemic and topical ALA administration protocols

Ponce Ayala,

Barreto Requena,

Salvador Bagnato

et al. 2024

Optical Methods for Tumor Treatment and Detection: Mechanisms and Techniques in Photodynamic Therapy XXXII

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Numerous studies are underway to identify an effective dynamic therapy against cutaneous melanoma. Dynamic therapy is based on the interaction of an external energy source and a molecule sensitive to this energy, which triggers a series of reactions resulting in tumor cell death. The adequate distribution and concentration of the sensitizer in tumor cells can lead to obtaining the expected anticancer effects. Protoporphyrin IX (PpIX) is a well-known endogenous sensitizer. Its accumulation in target cells can reach photosensitizing concentrations by the exogenous application of its precursor, 5-aminolevulinic acid (ALA). This study aimed to find an effective protocol for ALA delivery that induces a higher sensitizing PpIX deposition in murine cutaneous melanoma tumors. For this purpose, melanoma-bearing mice were subjected to five different protocols of ALA delivery: topical administration MAL cream (20% w/w methyl aminolevulinate hydrochloride, incubation time: 12h), intratumoral ALA injection (dose: 200 mg/Kg b.w., incubation time: 2 h), and intraperitoneal ALA injection (dose: 200 mg/Kg b.w., incubation time: 3, 4, 5 h). The amount of PpIX extracted from the melanoma tumors (B16F10) was compared with that extracted from a non-melanoma tumor model (A431) where the PpIX accumulation was induced by a clinical protocol of ALA delivery commonly applied for photodynamic therapy. The detection and quantification of PpIX were carried out by applying Steady-state fluorescence spectroscopy (SSFS) by in vivo and in vitro measurements, with the latter involving a chemical extraction method. In vitro measurements showed that the PpIX concentration extracted from the melanoma tumor was greater by intraperitoneal (3 h) (0.31±0.05 µM) and intratumoral (0.39±0.17 µM) protocols. Through the topical protocol, it was possible to avoid the healthy region sensitization, and the concentration of PpIX extracted from the melanoma tumor (0.15±0.04 µM) was almost the same amount as that generated by the clinical protocol (0.18±0.05 µM). The results suggested that a photosensitive amount of PpIX can be synthesized within the melanoma tumor by the intratumoral, intraperitoneal (3 h) protocols.

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Section: Introductionmentioning

confidence: 99%

Quantification of protoporphyrin IX in murine pigmented melanoma induced by systemic and topical ALA administration protocols

Ponce Ayala,

Barreto Requena,

Salvador Bagnato

et al. 2024

Optical Methods for Tumor Treatment and Detection: Mechanisms and Techniques in Photodynamic Therapy XXXII

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“…De acordo com os resultados descritos na literatura, como em (8,36,141) dentre outros, é possível verificar que certas condições do US levam à morte celular, ou seja, há indícios da existência de efeitos sonodinâmicos tanto em modelos in vitro como in vivo. Os valores comumente utilizados para os parâmetros ultrassônicos de finalidade terapêutica consistem em frequências entre 1 e 3 MHz, máximos de amplitude de pressão entre 0,1 e 1 MPa, ciclo de trabalho de 50% e 100% e tempo de irradiação variando de 2 a 30 minutos.…”

Section: Condições E Probabilidades Para a Nucleação E Cavitação Acús...unclassified

“…Os efeitos sonodinâmicos em meios biológicos, são gerados por uma combinação de fenômenos físicos e químicos que ocorrem no tecido devido à interação do US com o SS no meio. (8,141) Os fenômenos descritos e observados, como sonoluminescência, pirólise, ondas de choque e de cisalhamento, tem sua origem a partir da nucleação e das cavitações inercial e não inercial, o que torna fundamental o entendimento de todas as etapas e parâmetros necessários para a sua ocorrência.…”

Section: Condições E Probabilidades Para a Nucleação E Cavitação Acús...unclassified

“…Os valores de tensão superficial efetiva obtidos estão sumarizados na tabela (8). Tais valores foram implementados nas soluções das equações presentes neste trabalho bem como nos gráficos obtidos a partir das mesmas, afim de que fosse possível obter resultados energéticos de US mais próximos daqueles verificados experimentalmente nos estudos com SDT.…”

Section: Tensão Superficial Efetivaunclassified

“…Dentre tais terapias, podem-se citar as terapias dinâmicas: Fotodinâmica (PDT, do inglês Photodynamic Therapy) e Sonodinâmica (SDT, do inglês Sonodynamic Therapy). (8) A SDT é caracterizada pela combinação de ultrassom (US), um fármaco sonoativado, chamado de sonossenbilizador (SS) e oxigênio molecular (O 2 ). A energia entregue ao tecido devido à incidência de US e sua interação com o SS, excitam as moléculas de oxigênio e podem levar à morte celular.…”

Section: Introductionunclassified

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Sobre as condições e probabilidades para a nucleação e cavitação acústicas no tecido biológico - uma análise teórica

Antunes¹

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Este trabalho é dedicado à todas as mulheres que fizerem e fazem ciência, e também àquelas que disseminam o conhecimento científico dentro e fora das universidades. AGRADECIMENTOSAos meus pais Edson e Marlene, por me darem todo o apoio necessário para que eu pudesse chegar até aqui. Sem vocês o caminho que tracei não seria possível.À minha irmã Daniele, pelo apoio emocional em todas as situações e por sempre acreditar que eu seria capaz de chegar até aqui mesmo quando eu não o fiz.

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Evaluation of semisynthetic chlorophyll-a derivatives as photosensitizers in fibroblast cells

da Cruz Rodrigues,

Andrade Ono,

Ponce Ayala

et al. 2024

Optical Methods for Tumor Treatment and Detection: Mechanisms and Techniques in Photodynamic Therapy XXXII

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In this study, we present the evaluation in fibroblast cells of photosensitizers semi-synthesized derived from chlorophyll a (as described in literature). The process began with the extraction of methyl-pheophorbide a (1), which was then reacted with primary aliphatic amines (butylamine, hexylamine, and octylamine) to yield molecules 2 to 4. Additionally, purpurin-18 methyl ester (5) was obtained through the oxidation of methyl pheophorbide a (1). By adding different aliphatic amines (butylamine, hexylamine, and octylamine) into the anhydride ring of 5, products 6 to 8 were obtained. Compounds 2-4 and 6-8 exhibited absorption bands around 660 nm. The effectiveness of photosensitizers relies on their ability to selectively target damaged cells without harming healthy cells. Therefore, an evaluation of photosensitizers (2-4, 6-8, and chlorin-e6) against HFF-1 fibroblast cells was performed. Testing two different concentrations (1 and 10 µM), it was observed that, under dark conditions, the photosensitizers were primarily non-toxic as they did not significantly reduce cell viability and were close to the control group's viability. Furthermore, the impact of photodynamic therapy (PDT) on cell viability was analyzed by using a light fluence of 30 J/cm 2 . The lower polarity of the compounds (more lipophilic) improved the efficiency of the photosensitizers. In conclusion, this study highlights the successful development of cost-effective photosensitizers with potential applications in PDT. The evaluation against HFF-1 fibroblast cells showed promising results, indicating these photosensitizers could be further investigated for the selective treatment of damaged cells without causing harm to healthy cells.

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The Physics of Light and Sound in the Fight Against Skin Cancer

Cited by 6 publications

References 112 publications

Quantification of protoporphyrin IX in murine pigmented melanoma induced by systemic and topical ALA administration protocols

Quantification of protoporphyrin IX in murine pigmented melanoma induced by systemic and topical ALA administration protocols

Sobre as condições e probabilidades para a nucleação e cavitação acústicas no tecido biológico - uma análise teórica

Evaluation of semisynthetic chlorophyll-a derivatives as photosensitizers in fibroblast cells

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