Selective delivery of G-quadruplex ligand in glioma cell lines: the power of cyclic-RGD peptide.

Compounds targeting non-canonical secondary structures of nucleic acids, known as G-quadruplexes, are highly cytotoxic, both for cancer and healthy cells, because of their action mechanism's lack of appropriate selectivity. The targeted delivery of cytotoxic molecules to cancer cells is a valuable strategy to expand the repertoire of potential drugs, especially for cancer types for which new therapeutic tools are urgently needed, like glioblastoma. In this work, we conjugated a cyclic arginyl-glycyl-aspartic acid peptide to a naphthalene diimide, previously described as a highly performing stabilizing ligand for DNA G-quadruplexes, to specifically target glioma cells overexpressing RGD-binding integrin receptors.

cRGD-Functionalized Silk Fibroin Nanoparticles: A Strategy for Cancer Treatment with a Potent Unselective Naphthalene Diimide Derivative.

Developing drug delivery systems to target cytotoxic drugs directly into tumor cells is still a compelling need with regard to reducing side effects and improving the efficacy of cancer chemotherapy. In this work, silk fibroin nanoparticles (SFNs) have been designed to load a previously described cytotoxic compound (NDI-1) that disrupts the cell cycle by specifically interacting with non-canonical secondary structures of DNA. SFNs were then functionalized on their surface with cyclic pentapeptides incorporating the Arg-Gly-Asp sequence (RGDs) to provide active targeting toward glioma cell lines that abundantly express ανβ3 and ανβ5 integrin receptors.

Silk Fibroin Nanoparticle Functionalization with Arg-Gly-Asp Cyclopentapeptide Promotes Active Targeting for Tumor Site-Specific Delivery.

Arg-Gly-Asp (RGD)-based cyclopentapeptides (cRGDs) have a high affinity towards integrin αvβ3 and αvβ5, which are overexpressed by many tumor cells. Here, curcumin-loaded silk fibroin nanoparticles (SFNs) have been functionalized on the surface with cRGD to provide active targeting towards tumor cells; a "click reaction" between the RGD-based cyclopentapeptide carrying an azide group and triple-bond-functionalized nanoparticles has been exploited. Both naked and functionalized SFNs were less than 200 nm in diameter and showed a round-shaped morphology but, after functionalization, SFNs increased in size and protein molecular weight.