CC BY
11B-P-14
BIOMEDICAL PHOTONICS
Nanocomplexes for nanomaterial-based and enzyme-assisted
photodynamic therapy
A. Zakoyan1, L. Mkrtchyan1, N. Sarkisyan2, R. Grigoryan2, V. Tuchin3, G. Gyulkhandanyan1
1-Institute of Biochemistry, NAS of Armenia, 5/1, P. Sevak st., Yerevan 0014, Armenia 2-Institute of Molecular Biology, NAS of Armenia, 7, Hasratyan St., Yerevan 0014, Armenia 3-Science Medical Center, Saratov State University, 83 Astrakhanskaya st., Saratov 410012, Russia Main author email address: ann.zakoyan@yandex.ru
Photodynamic therapy (PDT) is an effective and minimally invasive therapeutic modality for the treatment of tumors. The efficacy of conventional PDT was usually limited by two factors: photosensitizer (PS) delivery to tumor and hypoxic solid tumor environment. To improve the efficacy of conventional PDT, nanomaterial-based and enzyme-assisted PDT (nano-ezPDT) was developed for enhanced PS delivery and reactive oxygen species (ROS) generation [1]. Smart nanocarriers (endogenous and exogenous enzymes), named enzyme-assisted nanocarriers (EANs), are designed to integrate enzymatic functions with nanomaterials for controlled delivery and enhanced efficacy. PS, oxygen and light are the necessities for a successful nano-ezPDT, which could be improved by an enzyme-mediated PS release, PS accumulation and ROS generation. The delivery of exogenous enzymes is EANs' inner encapsulation or surface anchoring. The PSs are loaded into EANs through either covalent or non-covalent linkages [1]. It is known that the enzyme ceru-loplasmin (CP) has an antitumor activity. Under certain conditions, CP is able to enhance free radical oxidation reactions, which leads to the inhibition of tumor cells [2]. This study was designed to evaluate the in vitro cytotoxicity and phototoxicity of the novel non-covalent complexes of CP with cationic porphyrins [CP+PS] for nanomaterial-based and enzyme-assisted PDT (nano-ezPDT). We obtained the non-covalent complex of CP and cationic porphyrin Zn-TBut4P-yP [CP+Zn-TBut4PyP] with concentrations of CP and Zn-TBut4PyP 1900 pg/ml 6.4 pg/ml, respectively, according to previously described method [3]. The cytotoxic and phototoxic effects of [CP+ Zn-TBut4PyP] complex on human adenocarcinoma HeLa cells (ATCC, US) were assessed using the MTT assay. The results shows that the [CP+Zn-TBut4P-yP] complex, its components CP and Zn-TBut4PyP with the same concentrations and Al-phthalocyanine currently used in PDT of tumors are not highly cytotoxic. The content of Al-phthalocyanine and Zn-TBut4PyP in the culture medium under in vitro conditions reduces the survival of the HeLa cell line under illumination with tungsten lamp by 59.8% and 67.9%, respectively. The Illumination of the medium containing the [CP+Zn-TBut4PyP] complex leads to the greatest decrease in the viability of the HeLa cell line relative to the control by 86.2%. The Illumination of the HeLa cell line in the presence of the [CP+Zn-TBut4PyP] complex in the culture medium leads to the formation of reactive oxygen species (including H2O2) and conformational changes in the CP. On the other hand, it is known that H2O2 in the presence of CP reacts with the DNA and breaks the strands, thus damaging cells in vitro [2]. Due to conformational changes in the enzyme component of the [CP+Zn-TBut4PyP] complex, free Cu2+ released. The generation of •OH radicals occurs, due to H2O2 and free Cu2+. Consequently, free radical oxidation reactions are enhanced which leads to greater inhibition of tumor cells: 1.3 times compared to free porphyrin Zn-TBut4PyP and 1.4 times than compared with Al-phthalocyanine used in PDT. This indicates a high potential of the obtained [CP+Zn-TBut4PyP] complex for nano-ezPDT. This study reveals that the novel complex [CP+Zn-TBut4PyP] on the base of CP and Zn-TBut4PyP cationic porphyrin could be a potential antitumor compound for nano-ezPDT. The obtained [CP+Zn-TBut4PyP] complex can be considered for further cervical cancer preclinical and in vivo testing.
[1] B. Du and C-H. Tung, Enzyme-assisted photodynamic therapy based on nanomaterials, ACS Biomater. Sci. Eng., vol. 6, pp. 2506-2517, (2020).
[2] T. P. Vavilova, Yu. N. Gusarova, O. V Korolyova, A. E. Medvedeva, Role of ceruloplasmin in neoplastic processes development, Biomedicinskaya khimia, vol. 51 (3), pp. 263-275, (2005).
[3] A. A. Zakoyan, Influence of light on optical absorption of photosensitizers and their complexes with human ceruloplasmin, Medical Science of Armenia, vol. 60 (3), pp. 62-70, (2020).
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