Gold nanoparticles loaded chitosan encapsulate 6-mercaptopurine as a novel nanocomposite for chemo-photothermal therapy on breast cancer

Amna H Faid; Samia A Shouman; Yehia A Badr; Marwa Sharaky; Elham M Mostafa; Mahmoud A Sliem

doi:10.1186/s13065-022-00892-0

Gold nanoparticles loaded chitosan encapsulate 6-mercaptopurine as a novel nanocomposite for chemo-photothermal therapy on breast cancer

BMC Chem. 2022 Nov 12;16(1):94. doi: 10.1186/s13065-022-00892-0.

Authors

Amna H Faid¹, Samia A Shouman², Yehia A Badr³, Marwa Sharaky², Elham M Mostafa³, Mahmoud A Sliem^{3

4}

Affiliations

¹ National Institute of Laser Enhanced Science (NILES), Cairo University, Giza, 12613, Egypt. amna.hussein@cu.edu.eg.
² National Cancer Institute (NCI), Cairo, 11796, Egypt.
³ National Institute of Laser Enhanced Science (NILES), Cairo University, Giza, 12613, Egypt.
⁴ Chemistry Department, Faculty of Science and Arts, Taibah University, Al-Ula, 100823, Saudi Arabia.

Abstract

Background: As a promising strategy to overcome the therapeutic disadvantages of 6-mercaptopurine (6MP), we proposed the encapsulation of 6MP in chitosan nanoparticles (CNPs) to form the 6MP-CNPs complexes. The encapsulation was followed by the loading of complexes on gold nanoparticles (AuNPs) to generate a novel 6MP-CNPs-AuNPs nanocomposite to facilitate the chemo-photothermal therapeutic effect.

Methods: CNPs were produced based on the ionic gelation method of tripolyphosphate (TPP). Moreover, 6MP-CNPs composite were prepared by the modified ionic gelation method and then loaded on AuNPs which were synthesized according to the standard wet chemical method using trisodium citrate as a reducing and capping agent. The synthesized nanocomposites were characterized by UV-VIS spectroscopy, dynamic light scattering, Fourier transform infrared spectroscopy, and transmission electron microscopy. The potential cytotoxicity of the prepared nanocomposites on MCF7 cell line was carried out using Sulphorhodamine-B (SRB) assay.

Results: Optimization of CNPs, 6MP-CNPs, and 6MP-CNPs-AuNPs revealed 130 ± 10, 200 ± 20, and 25 ± 5 nm particle size diameters with narrow size distributions and exhibited high stability with zeta potential 36.9 ± 4.11, 37, and 44.4 mV, respectively. The encapsulation efficiency of 6MP was found to be 57%. The cytotoxicity of 6MP-CNPs and 6MP-CNPs-AuNPs on breast cell line MCF7 was significantly increased and reached IC₅₀ of 9.3 and 8.7 µM, respectively. The co-therapeutic effect of the nanocomposites resulted in an improvement of the therapeutic efficacy compared to the individual effect of chemo- and photothermal therapy. Irradiation of 6MP-CNPs and 6MP-CNPs-AuNPs with a diode laser (DPSS laser, 532 nm) was found to have more inhibition on cell viability with a decrease in IC₅₀ to 5 and 4.4 µM, respectively.

Conclusion: The Chemo-Photothermal co-therapy treatment with novel prepared nanocomposite exhibits maximum therapeutic efficacy and limits the dosage-related side effects of 6MP.

Keywords: 6-mercaptopurine; Chemo-photothermal therapy; Chitosan loaded gold nanocomposites; Encapsulation efficiency; MCF7 cell line.