Investigation of Helicobacter pylori endogenous porphyrins as photosensitizers for intragastric PDT
Antonella Battistia, Paola Moricia, Giovanni Signoreb, Francesco Ghettia and Antonella Sgarbossaa
a Istituto Nanoscienze - CNR and NEST Scuola Normale Superiore, p.zza San Silvestro 12, 56127 Pisa, Italy
b NEST Scuola Normale Superiore and Center for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, p.zza San Silvestro 12, 56127 Pisa, Italy
The increasing resistance rates to conventional antibiotics demand new therapeutic strategies for Helicobacter pylori (Hp) eradication and in the last years non-pharmacological approaches have been considered. Antimicrobial PhotoDynamic Therapy (PDT) represents an alternative therapy, particularly promising in the case of Helicobacter pylori able to produce porphyrins, which may then act as endogenous photosensitizers.
With the aim to design and develop an ingestible LED-based robotic pill for intragastric phototherapy, so that irradiation can be performed in situ without the use of invasive endoscopic light, photophysical studies on the Hp endogenous photosensitizers are crucial. These studies represent an important prerequisite in order to select the most effective irradiation conditions for Hp eradication. The photophysical characterization of Hp porphyrins, including their spectroscopic features in terms of absorption, steady-state and time-resolved fluorescence, was performed on bacterial extracts as well as within planktonic and biofilm growing Hp cells1.Furthermore, the compositional analysis of Hp endogenous porphyrins has been performed by means of HPLC-MS combined with fluorescence techniques2.
Framework project: “CapsuLight - Design of an ingestible robotic pill based on LED sources for the treatment of gastrointestinal disorders” (CUP B52I14005760002) financed by Regione Toscana Bando FAS Salute 2014 (Italy).
1) A. Battisti, P. Morici, F. Ghetti, A. Sgarbossa, Spectroscopic characterization and fluorescence imaging of Helicobacter pylori endogenous porphyrins, Biophys. Chem. in press (2017) DOI: 10.1016/j.bpc.2017.05.010.
2) A. Battisti, P. Morici, G. Signore, F. Ghetti, A. Sgarbossa, Compositional analysis of endogenous porphyrins from Helicobacter pylori, Biophys. Chem. accepted for publication (2017)