Combinational siRNA Delivery Using Hyaluronic Acid Modified Amphiphilic Polyplexes Against Cell Cycle and Phosphatase Proteins to Inhibit Growth and Migration of Triple-Negative Breast Cancer Cells

Triple-negative breast cancer is an aggressive form of breast cancer with few therapeutic options if it recurs after adjuvant chemotherapy. RNA interference could be an alternative therapy for metastatic breast cancer, where small interfering RNA (siRNA) can silence the expression of aberrant genes critical for growth and migration of malignant cells. Here, we formulated a siRNA delivery system using lipid-substituted polyethylenimine (PEI) and hyaluronic acid (HA), and characterized the size, ζ-potential and cellular uptake of the nanoparticulate delivery system. Higher cellular uptake of siRNA by the tailored PEI/HA formulation suggested better interaction of complexes with breast cancer cells due to improved physicochemical characteristics of carrier and HA-binding CD44 receptors. The siRNAs against specific phosphatases that inhibited migration of MDA-MB-231 cells were then identified using library screen against 267 protein-tyrosine phosphatases and siRNAs to inhibit cell migration were further validated. We then assessed the combinational delivery of a siRNA against CDC20 to decrease cell growth and a siRNA against several phosphatases shown to decrease migration of breast cancer cells. Combinational siRNA therapy against CDC20 and identified phosphatases PPP1R7, PTPN1, PTPN22, LHPP, PPP1R12A and DUPD1 successfully inhibited cell growth and migration, respectively, without interfering with the functional effect of the co-delivered siRNA. The identified phosphatases could serve as potential targets to inhibit migration of highly aggressive metastatic breast cancer cells. Combinational siRNA delivery against cell cycle and phosphatases could be a promising strategy to inhibit both growth and migration of metastatic breast cancer cells, and potentially other types of metastatic cancer

Multiple siRNA Delivery Against Cell Cycle and Anti-Apoptosis Proteins Using Lipid-substituted Polyethylenimine in Triplenegative Breast Cancer and Non-Malignant Cells

Conventional breast cancer therapies have significant limitations that warrant a search for alternative therapies. Short-interfering RNA (siRNA), delivered by polymeric biomaterials and capable of silencing specific genes critical for growth of cancer cells, holds great promise as an effective and more specific therapy. Here, we employed amphiphilic polymers and silenced the expression of two cell cycle proteins, TTK and CDC20, and the anti-apoptosis protein survivin to determine the efficacy of polymer-mediated siRNA treatment in breast cancer cells as well as side effects in non-malignant cells in vitro. We first identified effective siRNA carriers by screening a library of lipid-substituted polyethylenimines (PEI), and PEI substituted with linoleic acid (LA) emerged as the most effective carrier for selected siRNAs. Combinations of TTK/CDC20 and CDC20/Survivin siRNAs decreased the growth of MDA-MB-231 cells significantly, while only TTK/CDC20 combination inhibited MCF7 cell growth. The effects of combinational siRNA therapy was higher when complexes were formulated at lower siRNA:polymer ratio (1:2) compared to higher ratio (1:8) in non-malignant cells. The lead polymer (1.2PEI-LA6) showed differential transfection efficiency based on the cell-type transfected. We conclude that the lipid-substituted polymers could serve as a viable platform for delivery of multiple siRNAs against critical targets in breast cancer therapy

<it>N</it>-hexanoyl chitosan stabilized magnetic nanoparticles: Implication for cellular labeling and magnetic resonance imaging

<p>Abstract</p> <p>This project involved the synthesis of <it>N</it>-hexanoyl chitosan or simply modified chitosan (MC) stabilized iron oxide nanoparticles (MC-IOPs) and the biological evaluation of MC-IOPs. IOPs containing MC were prepared using conventional methods, and the extent of cell uptake was evaluated using mouse macrophages cell line (RAW cells). MC-IOPs were found to rapidly associate with the RAW cells, and saturation was typically reached within the 24 h of incubation at 37°C. Nearly 8.53 ± 0.31 pg iron/cell were bound or internalized at saturation. From these results, we conclude that MC-IOPs effectively deliver into RAW cells <it>in vitro </it>and we also hope MC-IOPs can be used for MRI enhancing agents in biomedical fields.</p

T2 weighted MR images of a representive RAW cells incubated with different volume of MC-IOPs (11

2 mg/ml) for 5 h, (a) longitudinal section, (b) coronal section and (c) signal intensity of sample c to 3 (lane c~3; control, 50, 100 and 200 μl MC-IOPs, respectively).<p><b>Copyright information:</b></p><p>Taken from "-hexanoyl chitosan stabilized magnetic nanoparticles: Implication for cellular labeling and magnetic resonance imaging"</p><p>http://www.jnanobiotechnology.com/content/6/1/1</p><p>Journal of Nanobiotechnology 2008;6():1-1.</p><p>Published online 4 Jan 2008</p><p>PMCID:PMC2265288.</p><p></p

FTIR spectra of (a) pure chitosan, (b) MC, (c) pure IOPs and (d) MC-IOPs

<p><b>Copyright information:</b></p><p>Taken from "-hexanoyl chitosan stabilized magnetic nanoparticles: Implication for cellular labeling and magnetic resonance imaging"</p><p>http://www.jnanobiotechnology.com/content/6/1/1</p><p>Journal of Nanobiotechnology 2008;6():1-1.</p><p>Published online 4 Jan 2008</p><p>PMCID:PMC2265288.</p><p></p

TEM images of (a) pure IOPs, (b) MC-IOPs, (c) SAD pattern of MC-IOPs and (d) HRTEM image of MC-IOPs showing a 10 nm size magnetite nanoparticle with highly polycrystalline nature

<p><b>Copyright information:</b></p><p>Taken from "-hexanoyl chitosan stabilized magnetic nanoparticles: Implication for cellular labeling and magnetic resonance imaging"</p><p>http://www.jnanobiotechnology.com/content/6/1/1</p><p>Journal of Nanobiotechnology 2008;6():1-1.</p><p>Published online 4 Jan 2008</p><p>PMCID:PMC2265288.</p><p></p