Enhanced anticancer efficacy of folate-grafted lipid modified dual drug loaded nanoassemblies to reduce drug resistance in ovarian cancer

An outlook on procedures of conjugating folate to (co)polymers and drugs for effective cancer targeting

Folate receptors (FRs) are expressed in vast majority of cancers. Selective targeting of the FRs is, therefore, one of the most popular and sought-after strategies for improving the efficacy of cancer therapeutics. Variety of approaches involving folate conjugation to several well-known and novel, nontoxic, biodegradable, and biocompatible (co)polymers have been attempted and successfully applied to a large number of nanoparticulate drug delivery systems (micelles, liposomes, nanoparticles, quantum dots, mesoporous silica-based materials, and others) in the last decade-and-a-half. Standard and novel synthetic approaches were utilized for the conjugation, followed by the formulation of the drug delivery modality. In most of the cases, the targeted system lived up to its reputation, validating its usefulness in targeted cancer therapeutics. The present review summarizes the progress and state-of-the-art synthetic methodologies for folate conjugation to (co)polymers, drugs, and nucleic acids. The limitations of the FR targeting are discussed in brief to give the reader the other side of the story. Finally, the information on marketed folic acid conjugates highlight their industrial applications.

Direct Intranuclear Anticancer Drug Delivery via Polydimethylsiloxane Nanoparticles: in Vitro and in Vivo Xenograft Studies

Direct delivery of anticancer drugs to nuclei of tumor cells is required to enhance the therapeutic activity, which can be achieved by a nuclear localization signal (NLS) or peptide-decorated nanovehicles. However, NLS/peptide-based approaches may create certain undesirable immunological responses and the utilized synthesis processes are generally labor intensive. To this end, we report ligand-free, enhanced intranuclear delivery of Doxorubicin (Dox) to different cancer cells via porous polydimethylsiloxane (PDMS) nanoparticles (NPs). PDMS NPs were prepared by sacrificial silica template-based approach and Dox was loaded into the pores of PDMS NPs. These Dox-loaded PDMS NPs show enhanced cytotoxicity and reduce the IC50 values by 84 and 54% for HeLa and PC-3, respectively, compared to free Dox. Further, DNA damage in HeLa cells was estimated using comet assay suggesting enhanced DNA damage (72%) with Dox-loaded PDMS NPs as compared to free Dox (12%). The therapeutic efficiency of PDMS-Dox drug delivery system was tested in prostate cancer (PC-3) xenografts in NOD/SCID mice which showed enhanced tumor reduction (∼66%) as compared to free Dox. Taken together, our PDMS-Dox delivery system shows efficient and enhanced transportation of Dox to tumor cells which can be harnessed to develop advanced chemotherapy-based approaches to treat prostate and other cancers.