Research progress of the anti-tumor effect of sonodynamic and photodynamic therapy / 生物医学工程学杂志

Cancer, as a serious threat to human health, is one of the major killers. The treatment of cancer has attracted more and more attention. Currently, the means of treating cancer is also increasing, but there is no emergence of a fully satisfactory treatment. A combination of sonodynamic therapy (SDT) and photodynamic therapy (PDT), named sono-photodynamic therapy (S-PDT), is a new composite cancer therapy. Because the therapy can significantly improve the tumor curing effect, it has good application prospects in cancer prevention and treatment. The present article reviewed the progress of the anti-tumor mechanisms and influencing factors of S-PDT.

Hematoporphyrin derivative-mediated photodynamic therapy for human nasopharyngeal carcinoma: a comparative study with CNE2 and C666-1 cell lines in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate biological effect of hematoporphyrin derivative (HpD) photodynamic therapy (PDT) on in vitro cultured nasopharyngeal carcinoma (NPC) cell lines CNE2 and C666-1.</p><p><b>METHODS</b>CNE2 and C666-1 cells cultured in vitro were incubated in a medium containing HpD at different concentrations (0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, and 4.0 microg/ml) for 4 h followed by exposure to different light doses (2, 5, 10, and 20 J/cm2) using a diode laser at 630 nm with power density of 20 mW/cm2. After 24 h of incubation with HpD-PDT, the survival rate of CNE2 and C666-1 cells were analyzed by MTT assay.</p><p><b>RESULTS</b>HpD-PDT produced effective killing of CNE2 and C666-1 cells cultured in vitro, and the killing effects were positively correlated with HpD concentration and the irradiation dose. Exposure of CNE2 and C666-1 cells to irradiation dose of 20 J/cm2 resulted in the IC50 of 0.7 and 1.2 microg/ml, respectively (P<0.01). With the same HpD concentration and irradiation dose, the survival rate of C666-1 cells, however, was significantly higher than that of CNE2 cells (P<0.05).</p><p><b>CONCLUSION</b>HpD-PDT may result in effective killing of CNE2 and C666-1 cells cultured in vitro, although C666-1 cells are less sensitive to HpD-PDT than CNE2 cells.</p>

Main factors affecting the effect of photodynamic therapy against human esophageal cancer cells in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the tumor cell-killing effect of photodynamic therapy against human esophageal cancer cells in vitro and identify the main factors affecting the effect.</p><p><b>METHODS</b>Human esophageal cancer Eca-109 cells were incubated for 24 h in vitro with hematoporphyrin derivative (HpD) and Photofrin at different concentrations prior to exposure to a light energy density of 15 J/cm(2) delivered from a DIOMED 630 PDT system. The cell killing effect was also evaluated for different HpD concentrations combined with 3 light energy densities (10, 30, and 50 J/cm(2)), respectively. The cell survival rate was measured using MTT assay, and fluorescence spectrometry was used to detect the intracellular photosensitizer fluorescence of the tumor cells after incubation with HpD for 4 h.</p><p><b>RESULTS</b>The cell survival rate after incubation with the two photosensitizers at different concentrations were significantly different, and under the 3 different light energy densities, incubation of the cells with different HpD concentrations also resulted in significantly different cell survival rates (P<0.05). At the 4 low photosensitizer concentrations and with different light energy densities, the cell survival rates were similar (P>0.05), but the 4 higher photosensitizer concentrations resulted in significant difference in the cells survival (P<0.05). Correlation analysis showed that the intracellular photosensitizer concentration was positively correlated to the photosensitizer concentrations in cell incubation (r=0.997).</p><p><b>CONCLUSION</b>When the light source remains constant, the light energy density, the kinds of photosensitizers and their concentrations are the main factors affecting the Eca-109 cell-killing effect of PDT.</p>

Preparation of hematoporphyrin-herceptin photoimmunoconjugate for photoimmunotherapy / 南方医科大学学报

<p><b>OBJECTIVE</b>To prepare photoimmunoconjugate of hematoporphyrin (HP) and herceptin, and study its killing and apoptosis-inducing effect on tumor cells BT-474.</p><p><b>METHODS</b>HP-herceptin photoimmunoconjugate was synthesized with EDCI as the condensator. After exposure of the cells to 630 nm laser, the killing effect of the conjugate and cell apoptosis were evaluated by MTT assay and flow cytometry.</p><p><b>RESULTS</b>Compared with free HP at equivalent dose, the immune reactivity, killing effect and the apoptosis-inducing effect of HP-herceptin immunoconjugate on BT-474 cells was enhanced (P<0.05).</p><p><b>CONCLUSION</b>The killing effect of HP-herceptin immunoconjugate is stronger than free HP on BT-474 cells.</p>

Photodynamic therapy and its application in gynecologic oncology / 中国医学科学院学报

While photodynamic therapy is applied on neoplasm, photosensitisers tend to accumulate in neoplastic tissues. With appropriate wavelength light, it causes photochemical reaction and destructs neoplastic tissues. Its better selection for tumor tissue with effective photochemical reaction, and lower side effect make it widespread application in gynecologic oncology. At present, photodynamic therapy has been used in diagnosing and treating lower genital tract carcinoma in situ, and advanced malignant tumor such as vulval and ovarian carcinoma.

Intensificaçäo da terapia fotodinâmica do câncer do oxigênio no tecido: efeitos físicos e biológicos / Intensification of the photochemotherapy of the cancer of the oxygen in the tissue: physical and biological effects

A Terapia Fotodinâmica do Câncer (PDT) é baseada no envolvimento de três fatores, a saber: retençäo pelo tecido canceroso de um fotossensibilizador específico; iluminaçäo localizada da lesäo e ocorrência de oxigênio inicialmente no estado fundamental triplete. Na literatura científica sobre o assunto, encontravam-se vários trabalhos sobre a dosagem de fotossensibilizadores diversos e sobre a dosometria da radiaçäo visível capaz de provocar a terapia. O nível de oxigênio, por depender intrinsicamente do organismo tratado, tem sido tomado como um parâmetro constante na terapia e raramente estudado. No presente trabalho apresentamos pela primeira vez um desenvolvimento teórico que relaciona matematicamente o dano celular resultante do tratamento, com a variaçäo do aporte de oxigênio nas células cancerosas.

Interdependence of drug dose, incubation time & light dose on hematoporphyrin derivative induced photoinactivation of brain tumour cells.

The relationship between photosensitizer concentration, light dose, incubation time and cellular damage in human cerebral glioma cells in culture, was studied. Cells were incubated with hematoporphyrin derivative (Hpd) for different durations at 37 degrees C. Immediately after specified period of incubation, cells were irradiated with white light. Cellular damage was assessed by colony forming ability of cells. A progressive reduction in the surviving fraction was observed as a function of drug and light dose. The survival curves were of exponential nature with an initial shoulder. The cell survival was found to be dependent on the time of incubation with Hpd. These results suggest that photodynamic cellular damage can be enhanced at low drug and light dose by increasing the incubation time.

Fotorradiaçäo por laser e hematoporfirina no tratamento de tumores malignos / Lasers photoradiation and hematoporphyrin in the treatment of malignant tumors

Revisou-se a literatura acerca da utilizaçäo da hematoporfirina associada à luz, no tratamento de tumores malignos. Foram apresentadas as hipóteses formuladas sobre o mecanismo de açäo desta associaçäo, assim como resumidos os diferentes métodos utilizados, seja em animais de experimentaçäo, seja no homem. Foram também expostos os resultados obtidos da literatura, efetuando-se os comentários sobre esta opçäo para o tratamento de neoplasias malignas

Inducing effect of hematoporphyrin derivative (HpD) on cell sister chromatid exchanges (SCE) in vitro / 中华肿瘤杂志

The mutagenic effect of HpD on cell SCE and the reactions of cell SCE to different sources of light combined with HpD were studied using V79 cells. There were 6 doses of HpD: 1 microgram/ml, 3 micrograms/ml, 5 micrograms/ml, 10 micrograms/ml, 50 micrograms/ml and 100 micrograms/ml. The dose of 5 micrograms/ml is equal to the maximum dose of HpD used in the clinic (HpD per milliliter of patient's blood). Our experiments demonstrated that when the cells were cultured in the dark and HpD was added to the medium no more than 5 micrograms/ml, the SCE frequencies were not increased. The cells were irradiated with different sources of light without HpD, both the fluorescence and ultraviolet light could promote SCE but the light of daylight lamp and red light did not increase it. But when HpD was added into culture medium at the dose of less than 5 micrograms/ml, every light could increase the cell SCE intensively except the daylight lamp light. The red light was more notable than the others by relation analysis.