Background:
Among the numerous bio-responsive polymeric drug delivery systems developed recently,
redox-triggered release of molecular payloads have gained great deal of attention, especially in the field of
anticancer drug delivery. In most cases, these systems rely on disulfide bonds located either in the matrix crosslinks,
or in auxiliary chains to achieve stimuli-responsive drug release. These bonds keep their stability in extracellular
environments, yet, rapidly break by thiol–disulfide exchange reactions in the cytosol, due to the presence
of greater levels of glutathione. Polysaccharides are macromolecules with low cost, natural abundance,
biocompatibility, biodegradability, appropriate physical and chemical properties, and presence of numerous functional
groups which facilitate chemical or physical cross-linking.
Methods:
With regards to the remarkable advantages of polysaccharides, in the current study, various
polysaccharide-based redox-responsive drug delivery systems are reviewed. In most cases the in vitro/in vivo
effects of the developed system were also evaluated.
Results:
Considering the hypoxic and reducing nature of the tumor microenvironment, with several folds higher
glutathione levels than the systemic tissues, redox-sensitive polymeric systems could be implemented for tumorspecific
drug delivery and the results of the previous researches in this field indicated satisfactory achievements.
Conclusion:
According to the reviewed papers, the efficiency of diverse redox-responsive polysaccharide-based
nanoparticles with therapeutic payloads in cancer chemotherapy could be concluded. Nevertheless, more comprehensive
studies are required to understand the exact intracellular and systemic fate of these nano-carriers, as well
as their clinical efficacy for cancer treatment.
Advances in redox-responsive drug delivery systems of tumor microenvironment