Galactoxyloglucan-modified nanocarriers of doxorubicin for improved tumor-targeted drug delivery with minimal toxicity

Doxorubicin (Dox) is commonly used to treat human malignancies, and the efficacy of Dox can be maximized by limiting toxicity when combined with nanoparticles. PST-Dox nanoparticles were prepared via conjugation of doxorubicin to galactoxyloglucan polysaccharide (PST001) isolated from Tamarindus indica (Ti), and by ionic gelation with tripolyphosphate (TPP). This formulation possessed superior therapeutic efficiency because of the small size and increased surface-to-volume ratio. The PST-Dox nanoparticles exhibited a pH-responsive Dox release in the acidic pH of 4.5, favoring as high as 90% Dox release in a sustainable manner. PST-Dox was characterized and evaluated for its in vitro and in vivo anticancer effects. Surprisingly, this nanoparticle formulation retained the cytotoxic effects of PST001 even at lower concentrations. In vitro studies confirmed the selective cytotoxicity of PST-Dox in cancer cells through the induction of apoptosis. In vivo toxicity studies demonstrated a lower LD50 for Dox and a higher LD50 for the PST-Dox. Evaluation of the biochemical, hematological and histopathological parameters in mice supported the safety and efficacy of this formulation compared to Dox. Biodistribution data substantiated the tumor-specific delivery of these particles. Although prospective studies are warranted, in a complex disease such as cancer, cell-selective and pH-sensitive nanoparticle-based targeted drug delivery systems should be used as an effective choice over standard agents, such as doxorubicin.