Plant-derived chlorophyll derivative loaded liposomes for tri-model imaging guided photodynamic therapy

Abstract

In this work, a liposome-encapsulated chlorophyll derivative pyropheophorbide acid (PPa) (liposome/PPa) nanoparticles are designed for tri-model imaging guided photodynamic therapy (PDT) of cancer.

COVID-19 Therapy: Could a Chlorophyll Derivative Promote Cellular Accumulation of Zn2+ Ions to Inhibit SARS-CoV-2 RNA Synthesis?

“…While our understanding of the metabolic processes of zinc transporters remains limited, it is plausible to speculate that ZnPh combined with zinc supplementation could reach deep inside human lungs (Jakubowska et al, 2013). This would increase the cellular concentration of Zn 2+ to target cells such as alveolar epithelia (Hagimori et al, 2019), corroborating in vitro studies on the free ionisation of Zn 2+ (Szczygieł et al, 2008;Tamiaki et al, 2012;Hagimori et al, 2019;Zhou et al, 2019). Additionally, such raised intracellular levels may be achieved independently of the need for a cytotoxic effect experienced both in the dark and upon illumination, eliminating associated risks of singlet oxygen stress, ionisation and phosphorylated nuclear cell damage.…”

“…Pre-clinical and clinical safety tests on ZnPh are required. However, it is generally accepted that toxicity is dependent on a photo-reactive response (Tao et al, 1990;Hwang et al, 2005;Szczygieł et al, 2008;Tamiaki et al, 2012;Jakubowska et al, 2013;Ocakoglu et al, 2015;Martinez De Pinillos Bayona et al, 2017;Zhou et al, 2019;Tamiaki et al, 2020), given that phototoxicity induced by ZnPh is short-lived (Ahn et al, 2012;Jakubowska et al, 2013;Ocakoglu et al, 2015;Solymosi and Mysliwa-Kurdziel, 2017). Rapid clearance of zinc chlorophyll compounds is observed in human cell lines, with low doses invoking no or limited cytotoxic effect (Tao et al, 1990;Tang et al, 2006;Jakubowska et al, 2013;Ocakoglu et al, 2015;Martinez De Pinillos Bayona et al, 2017;Diogo et al, 2018).…”

“…Zn 2+ ions attached to this tetrapyrrole derivative can pass through cell membranes as it is water-soluble. Aggregation and accumulation by different organelles of pheophorbide a and other chlorophyll breakdown products, both with and without Zn 2+ , are demonstrated in many studies (Tao et al, 1990;Szczygieł et al, 2008;Yoon et al, 2011;Ahn et al, 2012;Tamiaki et al, 2012;Xodo et al, 2012;Jakubowska et al, 2013;Ocakoglu et al, 2015;Ahn et al, 2017;Kang et al, 2018;Mokwena et al, 2018;Singh et al, 2019;Zhou et al, 2019;Tamiaki et al, 2020). Interestingly, no localization of ZnPh to mitochondria has been observed (Jakubowska et al, 2013;Ocakoglu et al, 2015).…”

Exploiting Lipid and Polymer Nanocarriers to Improve the Anticancer Sonodynamic Activity of Chlorophyll

“…Despite that, the array of photoproperties, biocompatibility and natural abundance of chlorophyll make it a suitable sonosensitizer candidate for SDT application [19], even if the hydrophobicity of the chlorophyll macrocycle is a limit that cuts down the applications in aqueous environment. Therefore, some chlorophyll derivatives have been obtained and associated to colloidal carriers, such as micelles, ethosomes, liposomes, and nanoparticles, but only for PDT applications [20][21][22][23][24][25]. This is the first work that investigates chlorophyll as it is in nature, such as a mixture of different chlorophyll molecules, including chlorophyll a, b and pheophytin a.…”

Photodynamic therapy: photosensitizers and nanostructures

“…One possible improvement in this direction has been reported for liposomes loaded with tetraphenylporphyrin (TPP), that can be incorporated into the liposome at high concentrations via an exchange reaction from previously formed cyclodextrin/porphyrin complexes 158. With the objective of multifunctionality, some PSs such as the hydrophobic pyropheophorbide acid, a chlorophyll derivative which can be used either as a PS and as a fluorescent reagent, are encapsulated into a liposome structure and can be employed for imaging guided photodynamic therapy 167. As previously commented on, another of the advantages of liposomes is the possible incorporation of both hydrophilic and hydrophobic cargos, and this allow the design of multi therapy systems.…”