PEGylated bis-indolyl polyurethane dendrimers with anti-cancer activity as carriers for doxorubicin to treat lung cancer cells

Drug carriers designed with requisite features are important for the formulation of improved drug delivery system. This article describes the PEGylation of G3 polyurethane dendrimers comprising bio active bis-indole groups using polyethylene glycol monomethyl ether of molecular weight 750 and 2000 g mol −1 and encapsulation of doxorubicin (DOX) in the interior of the dendrimers. The drug carriers prepared were characterized thoroughly, and the loading of the DOX with the carriers was confirmed using UV spectroscopy. Drug loading and release properties revealed that the dendrimer conjugated with PEG-2000 was found to accommodate more numbers of DOX molecules and it released the drug for longer time. The results of cytotoxicity and cellular uptake studies carried out with human lung cancer cells (A549) and normal lung cells (L132) revealed that the bis-indolyl dendrimers, i.e., the carrier molecules themself contributed cytotoxicity to cancer cells in addition to DOX and also confirmed that G3-PEG-2000/DOX combination was more efficient compared to G3-PEG-750/DOX combination for inducing apoptosis type cell death. Graphical abstract