Spectroscopic Assessment of Doxorubicin (DOX)-Gemcitabine (GEM) Gold Complex Nanovector as Diagnostic Tool of Galectin-1 Biomarker

Introduction: The aim of this study is focused on the development of theranostic hybrid nanovectors based on gold-doxorubicin (DOX)-gemcitabine (GEM) complexes and their active targeting with Galectin-1 (Gal-1) as a promising therapeutic and prognostic marker in cancer.

Methods: For this purpose, a gold salt (HAuCl₄) interacts with antitumor drugs (DOX; GEM) by chelation and then stabilizes with dicarboxylic acid-terminated polyethylene glycol (PEG) as a biocompatible surfactant. The proposed methodology is fast and reproducible, and leads to the formation of a hybrid nanovector named GEM@DOX IN PEG-AuNPs, in which the chemo-biological stability was improved. All synthetic chemical products were evaluated using various spectroscopic techniques (Raman and UV-Vis spectroscopy) and transmission electron microscopy (TEM).

Results: To conceive a therapeutic application, our hybrid nanovector (GEM@DOX IN PEG-AuNPs) was conjugated with the Galectin-1 protein (Gal-1) at different concentrations to predict and specifically recognize cancer cells. Gal-1 interacts with GEM@DOX in PEG-AuNPs, as shown by SPR and Raman measurements. We observed both dynamic variation in the plasmon position (SPR) and Raman band with Gal-1 concentration.

Discussion: We identified that GEM grafted electrostatically onto DOX IN PEG-AuNPs assumes a better chemical conformation, in which the amino group (NH₃⁺) reacts with the carboxylic (COO^-) group of PEG diacide, whereas the ciclopenthanol group at position C-5' reacts with NH₃⁺ of DOX.

Conclusion: This study opens further way in order to built "smart nanomedical devices" that could have a dual application as therapeutic and diagnostic in the field of nanomedicine and preclinical studies associated.