BackgroundA folate-receptor-targeted poly (lactide-co-Glycolide) (PLGA)-Polyethylene glycol (PEG) nanoparticle is developed for encapsulation and delivery of disulfiram into breast cancer cells. After a comprehensive characterization of nanoparticles, cell cytotoxicity, apoptosis induction, cellular uptake and intracellular level of reactive oxygen species are analyzed. In vivo acute and chronic toxicity of nanoparticles and their efficacy on inhibition of breast cancer tumor growth is studied.ResultsThe folate-receptor-targeted nanoparticles are internalized into the cells, induce reactive oxygen species formation, induce apoptosis and inhibit cell proliferation more efficiently compared to the untargeted nanoparticles. The acute and toxicity test show the maximum dose of disulfiram equivalent of nanoparticles for intra-venous injection is 6 mg/kg while show significant decrease in the breast cancer tumor growth rate.ConclusionIt is believed that the developed formulation could be used as a potential vehicle for successful delivery of disulfiram, an old and inexpensive drug, into breast cancer cells and other solid tumors.Graphical abstractDisulfiram, an old and inexpensive drug, is encapsulated in folate-targeted PLGA-PEG nanoparticles and delivered into breast cancer cells using passive and active targeting to inhibit tumor growth in mice

Monocytes and macrophages are key players in maintaining immune homeostasis. identifying strategies to manipulate their functions via gene delivery is thus of great interest for immunological research and biomedical applications. We set out to establish conditions for mRnA transfection in hard-to-transfect primary human monocytes and monocyte-derived macrophages due to the great potential of gene expression from in vitro transcribed mRnA for modulating cell phenotypes. mRnA doses, nucleotide modifications, and different carriers were systematically explored in order to optimize high mRNA transfer rates while minimizing cell stress and immune activation. We selected three commercially available mRnA transfection reagents including liposome and polymer-based formulations, covering different application spectra. Our results demonstrate that liposomal reagents can particularly combine high gene transfer rates with only moderate immune cell activation. For the latter, use of specific nucleotide modifications proved essential. In addition to improving efficacy of gene transfer, our findings address discrete aspects of innate immune activation using cytokine and surface marker expression, as well as cell viability as key readouts to judge overall transfection efficiency. The impact of this study goes beyond optimizing transfection conditions for immune cells, by providing a framework for assessing new gene carrier systems for monocyte and macrophage, tailored to specific applications. Innate immune cells play an important role in response to pathological conditions and maintaining immune homeostasis 1. Among them, monocytes and monocyte-derived macrophages have remarkable properties, including their immunomodulatory capacities. Monocytes with various distinct phenotypes are key players of early inflammation. During inflammation, monocytes can dynamically repolarize to different phenotypes in response to local signals, which is thought to be more efficient at resolving tissue homeostasis than the recruitment of other anti-inflammatory and pro-regenerative subsets of monocytes or macrophages 2-4. Macrophages themselves have special functions such as phagocytosis of invading pathogens or apoptotic cells, antigen presentation to T cells, elimination of pathogens via releasing reactive oxygen species or proteolytic enzymes, and secretion of pro-or anti-inflammatory signaling molecules to recruit various types of other immune cells 5-9. Elucidation and manipulation of monocyte and macrophage phenotypes is therefore essential to fully explore their role in immunoregulation. This will benefit not only basic immunological research but also clinical and translational studies 3,10,11. For innate immune cell manipulation, transfections have been commonly used to introduce nucleic acids, such as plasmid DNA (pDNA) or small interfering RNA, to induce or inhibit the expression of a target protein,