Photodynamic inactivation

Kasermann, F., and Kempf, C. (1997) Photodynamic inactivation of enveloped viruses by buckminster-fullerene. Antivir. Res. 34, 65-70. 

Although HIV infection inhibition is mainly due to interaction of fullerene derivatives with viral enzymes, it is necessary to consider that this is not the only exploitable mechanism. In fact, the photodynamic inactivation of influenza vims has also been proposed (Zarubaev et al., 2007). The outer viral membrane is destroyed, while it seems that the protein profile of allantoic fluid, in which the vims was propagated, remains unchanged, confirming one more time the great potentiality of fullerene. 

Zarubaev VV, Belousova IM, Kiselev OI, Piotrovsky LB, Anfimov PM, Krisko TC, Muraviova TD, Rylkov VV, Starodubzev AM, Sirotkin AC (2007) Photodynamic inactivation of influenza virus with fullerene C60 suspension in allantoic fluid. Photodiagn. Photodyn. Ther. 4 31-35. 

We have shown, in a series of reported experiments that cationic fullerenes fulfill many, but not all the aforementioned criteria. Our laboratory was the first to demonstrate that the soluble functionalized fullerenes described above, especially the cationic compounds BF4-BF6, were efficient antimicrobial PS and could mediate photodynamic inactivation (PDI) of various classes of microbial cells (Tegos et al., 2005). We used a broadband-pass filter giving an output of the entire visible spectrum (400-700 nm) to excite the fullerenes that maximized the absorption. 

Kasermann F, Kempf C (1998) Buckminsterfullerene and photodynamic inactivation of viruses. Rev Med Virol 8 143-151. 

Spesia MB, Milanesio ME, Durantini EN (2008) Synthesis, properties and photodynamic inactivation of Escherichia coli by novel cationic fullerene C(60) derivatives. Eur J Med Chem 43(4) 853-861. 

Photodynamic Inactivation of Enveloped Viruses by Fullerene Study of Efficacy and Safety... 

The purpose of the present study was to investigate a photodynamic inactivation of influenza vims in the allantoic fluid of chicken embryos. Further, we have evaluated nonspecific effects of photodynamic treatment on the components of biological fluids. 

In the present study we have investigated the process of photodynamic inactivation of influenza vims in the allantoic fluid of chicken embryos. This inactivation has been realized by C60 water suspension used as a photosensitizer. Similar studies have been carried out previously by Kaserman and Kempf (1997, 1998). Unlike the latter studies, in which viruses were inactivated in salt solutions (buffer), our experiments were performed in a natural biological fluid that contains all typical components (proteins, lipids, salts, etc.). Comparing the viral inactivation over time in our experiments with previous results we conclude that the process described by Kaserman and Kempf (1997, 1998) was more time-consuming, a fact that may significantly restrict its practical use. 

The course of viral photodynamic inactivation in allantoic fluid is probably directed by the following process the initial period of induction is a result of the quenching of singlet oxygen (or other reactive forms of oxygen) by natural antioxidants present in the fluid (Kolb, 1991). Subsequently, a dramatic drop in the viral titer was observed. This then reached a plateau due to the consumption of the active fraction of the fullerene. This may be indirectly confirmed by the results of viral titration after the addition of a new portion of fullerene when the process of inactivation was observed again. 

Studies have been conducted for the intactness of biological fluids after photochemical treatment, in particular, proteins of allantoic fluid and blood semm, by methods of spectrophotometry and gel electrophoresis. The growth properties of semm were evaluated in cell culture. The protein composition of biological fluid was shown not to undergo dramatic changes during the course of photodynamic inactivation of vimses. 

Ender A et al. (2004) Screening of blood donations for HIV-1 and HCV RNA by transcription-mediated amplification assay one year experience. Transfus Med Hemother. 31 10-15. Kasermann F, Kempf C (1997) Photodynamic inactivation of enveloped viruses by buckminster-fullerene. Antiviral Res. 34 65-70. 

Recently, it has been shown that photoactive fullerene derivatives (Cgo) were very effective in the photodynamic inactivation of bacterial viruses (bacteriophages). The treatment of water with CgQ-based PS under illumination resulted in a 2-log reduction in the number of bacteriophages in the water within only 2 min (Lee et ah, 2009). 

Several papers have been published on the photodynamic inactivation of microorganisms in waste water treatment (Acher and Juven, 1977 Gerba et al., 1977a,b, Kussovski et al., 2001 Martin and Perez-Cruet, 1987). Despite the fact that the effectiveness of photodynamic disinfection... 

TABLE 3.8 Photodynamic inactivation of microorganisms on the surface of paper treated with conjugates of Rose Bengal (RB) and Phloxine B (PhB) with poly (vinyl amine) (PVAm) (adapted from Brovko et ai, 2009)... 

Demidova, T. N. and Hamblin, M. R. (2005b). Photodynamic inactivation of Bacillus spores, mediated by phenothiazinium dyes. Appl. Environ. Microbiol. 71, 6918-6925. 

Kussovski, V., Mantaraeva, V., Angelov, I., Orozova, P., Wohrle, D., Schnurpfeil, G., Borisova, E., and Avramov, L. (2009). Photodynamic inactivation of Aeromonas hydrophilia by cationic phthalocyanines with different hydrophobicity. FEMS Microbiol. 294(2), 133-140. 

Tsai, T., Yang, Y. T., Wang, T. H., Chien, H. F., and Chen, C. T. (2009). Improved photodynamic inactivation of Gram-positive bacteria using hematoporphyrin encapculated in liposomes and micelles. Lasers Surg. Med. 41(4), 316-322. 

The cytotoxic and photodynamic inactivation of microorganisms by Rose Bengal is an important line of research [337]. Rose Bengal causes ATP depletion [338] in killing Escherichia coli B/r [339]. Since E. coli is also killed... 

Positively charged photosensitizers, particularly cationic metallophthalocy-anines, have been proved to be most efficient in photodynamic inactivation of both Gram-negative and -positive bacteria. The reason is believed to lie in the electrostatic interaction of cationic photosensitizer with negatively charged sites at the outer surface of the bacterial cell wall, which facilitates the photosensitizer molecule binding to bacterial cells. 

Fundamentals of heterogeneous photocatalysis have been described in Chapter 7. The photodynamic activity of Ti02 (based on its photocatalytic activity and high efficiency in ROS generation) can find applications in photodynamic therapy (PDT) and photodynamic inactivation of microorganisms (PDI), described in Chapters 17 and 18, respectively. Selected environmental aspects of heterogeneous photocatalysis are described below. 

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