Delivery of Multiple siRNAs Using Lipid-Coated PLGA Nanoparticles for Treatment of Prostate Cancer

Nanotechnology can provide a critical advantage in developing strategies for cancer management and treatment by helping to improve the safety and efficacy of novel therapeutic delivery vehicles. This paper reports the fabrication of poly(lactic acid-co-glycolic acid)/siRNA nanoparticles coated with lipids for use as prostate cancer therapeutics made via a unique soft lithography particle molding process called PRINT (Particle Replication In Nonwetting Templates). The PRINT process enables high encapsulation efficiency of siRNA into neutral and monodisperse PLGA particles (32–46% encapsulation efficiency). Lipid-coated PLGA/siRNA PRINT particles were used to deliver therapeutic siRNA in vitro to knockdown genes relevant to prostate cancer

Analysis of the Murine Immune Response to Pulmonary Delivery of Precisely Fabricated Nano- and Microscale Particles

Nanomedicine has the potential to transform clinical care in the 21st century. However, a precise understanding of how nanomaterial design parameters such as size, shape and composition affect the mammalian immune system is a prerequisite for the realization of nanomedicine's translational promise. Herein, we make use of the recently developed Particle Replication in Non-wetting Template (PRINT) fabrication process to precisely fabricate particles across and the nano- and micro-scale with defined shapes and compositions to address the role of particle design parameters on the murine innate immune response in both in vitro and in vivo settings. We find that particles composed of either the biodegradable polymer poly(lactic-co-glycolic acid) (PLGA) or the biocompatible polymer polyethylene glycol (PEG) do not cause release of pro-inflammatory cytokines nor inflammasome activation in bone marrow-derived macrophages. When instilled into the lungs of mice, particle composition and size can augment the number and type of innate immune cells recruited to the lungs without triggering inflammatory responses as assayed by cytokine release and histopathology. Smaller particles (80×320 nm) are more readily taken up in vivo by monocytes and macrophages than larger particles (6 µm diameter), yet particles of all tested sizes remained in the lungs for up to 7 days without clearance or triggering of host immunity. These results suggest rational design of nanoparticle physical parameters can be used for sustained and localized delivery of therapeutics to the lungs

Plasma, tumor and tissue pharmacokinetics of Docetaxel delivered via nanoparticles of different sizes and shapes in mice bearing SKOV-3 human ovarian carcinoma xenograft

The particle fabrication technique PRINT® was used to fabricate monodisperse size and shape specific poly(lactide-co-glycolide) particles loaded with the chemotherapeutic Docetaxel. The pharmacokinetics of two cylindrical shaped particles with diameter=80nm; height=320nm (PRINT-Doc-80×320) and d=200nm; h=200nm (PRINT-Doc-200×200) were compared to Docetaxel in mice bearing human ovarian carcinoma SKOV-3 flank xenografts. The Docetaxel plasma exposure was ~20-fold higher for both particles compared to docetaxel. Additionally, the volume of distribution (Vd) of Docetaxel in PRINT formulations was ~18-fold (PRINT-Doc-80×320) and ~33-fold (PRINT-Doc-200×200) lower than Docetaxel. The prolonged duration of Docetaxel in plasma when dosed with PRINT formulations subsequently lead to increased tumor exposure of Docetaxel from 0-168 hours (~53% higher for PRINT-Doc-80×320 and ~76% higher for PRINT-Doc-200×200 particles). PRINT-Doc-80×320 had lower exposures in the liver, spleen and lung compared with PRINT-Doc-200×200. Thus, the use of particles with smaller feature size may be preferred to decrease clearance by organs of the mononuclear phagocyte system

Screening Nanopyramid Assemblies to Optimize Surface Enhanced Raman Scattering

This Letter describes how gold pyramidal nanoshells (nanopyramids) can be assembled into low- and high-order structures by varying the rate of solvent evaporation and surface wettability. Single-particle and individual-cluster dark field scattering spectra on isolated dimers and trimers of nanopyramids were compared. We found that the short-wavelength resonances blue-shifted as the particles assembled; the magnitude of this shift was greater for high-order structures. To test which assembled architecture supported a larger Raman-active volume, we compared their surface-enhanced Raman scattering (SERS) response of the resonant Raman molecule methylene blue (λ_ex = 633 nm). We discovered that high-order structures exhibited more Raman scattering compared to low-order assemblies. Finite difference time domain modeling of nanopyramid assemblies revealed that the highest electromagnetic field intensities were localized between adjacent particle faces, a result that was consistent with the SERS observations. Thus, the local spatial arrangement of the same number of nanoparticles in assembled clusters is an important design parameter for optimizing nanoparticle-based SERS sensors

Hydrogel particles remain in the lungs for multiple days without overt signs of inflammation.

<p><b>A)</b> 6 µm hydrogel particles (denoted by red arrows) are visible in the alveolar spaces 2 days after intratracheal installation. Lower insets are a magnified view of black bounding box. PBS treated mice are shown as control. <b>B)</b> Multiple 6 µm hydrogel particles (denoted by black bounding box and red arrows) are visible in the alveolar spaces 7 days after intratracheal installation. <b>C)</b> Two days after treatment with hydrogel particles, BALF cells were stained and visualized for particle uptake via epifluorescence microscopy. Particles (Dylight 650, red); nuclei (DAPI, blue); F-actin (Phalloidin 488, green). <b>D)</b> Magnified views of BALF cells taking up hydrogel particles as denoted by white bounding boxes in Figure C. <b>E)</b> Quantification of particle uptake indicates smaller particles are more readily taken up in BALF cells than larger particles. <b>F)</b> All types of hydrogel particles can still be seen in BALF cells seven days after treatment, though there is a marked decrease in the number of particles present as compared to the 2 day time point. <b>G)</b> Magnified views of BALF cells taking up hydrogel particles 7 days after treatment as denoted by white bounding boxes in Figure C. Scale bar is 20 µm. Data shown are representative of at least two independent experiments.</p

PRINT particles do not cause inflammation in bone marrow-derived macrophages from BALB/c or C57BL/6 mice.

<p><b>A)</b> Overnight stimulation with a panel of PRINT PLGA and hydrogel particles (PEG) at 100 µg/ml does not cause TNF-α, IL-6, or IL-1β release from bone marrow-derived macrophages from C57BL/6 mice as measured by ELISA. <b>B)</b> Both PLGA and hydrogel PRINT particles (PEG) tested negative for endotoxin contamination using a Limulus amebocyte lysate assay. <b>C)</b> PRINT particles are not cytotoxic in bone-marrow derived macrophages as determined by lactate dehydrogenase (LDH) release. <b>D)</b> 80×320 nm PLGA particles do not synergize with LPS to induce inflammasome activation as measured by IL-1β ELISA in BALB/c bone-marrow derived macrophages. <b>E)</b> Neither 80×320 nm nor 1 µm PLGA particles synergize with LPS to induce inflammasome activation as measured by IL-1β ELISA in C57BL/6 bone-marrow derived macrophages. MSU was dosed at 300 µg/ml. *** = p<0.001. Experiments were performed in triplicate. Data shown are representative of at least three independent experiments.</p

PRINT Particle Characterization.

<p><b>A)</b> Dynamic light scattering (DLS) and zeta potential measurements of PLGA particles used in studies. Particle charge decreases with increasing size. <b>B)</b> Scanning electron microscope (SEM) images of PLGA particles. <b>C)</b> PEG particle composition and characterization. <b>D)</b> SEM of PEG particles. <b>E)</b> Confocal images of hydrogel particle uptake in MH-S alveolar macrophage cells after 4 hours of treatment. Scale bar is 50 µm.</p

Delivery of Multiple siRNAs Using Lipid-Coated PLGA Nanoparticles for Treatment of Prostate Cancer

Nanotechnology can provide a critical advantage in developing strategies for cancer management and treatment by helping to improve the safety and efficacy of novel therapeutic delivery vehicles. This paper reports the fabrication of poly­(lactic acid-<i>co</i>-glycolic acid)/siRNA nanoparticles coated with lipids for use as prostate cancer therapeutics made via a unique soft lithography particle molding process called Particle Replication In Nonwetting Templates (PRINT). The PRINT process enables high encapsulation efficiency of siRNA into neutral and monodisperse PLGA particles (32–46% encapsulation efficiency). Lipid-coated PLGA/siRNA PRINT particles were used to deliver therapeutic siRNA in vitro to knockdown genes relevant to prostate cancer

Plasma, tumor and tissue pharmacokinetics of Docetaxel delivered via nanoparticles of different sizes and shapes in mice bearing SKOV-3 human ovarian carcinoma xenograft

The particle fabrication technique PRINT® was used to fabricate monodisperse size and shape specific poly(lactide-co-glycolide) particles loaded with the chemotherapeutic Docetaxel. The pharmacokinetics of two cylindrical shaped particles with diameter=80nm; height=320nm (PRINT-Doc-80×320) and d=200nm; h=200nm (PRINT-Doc-200×200) were compared to Docetaxel in mice bearing human ovarian carcinoma SKOV-3 flank xenografts. The Docetaxel plasma exposure was ~20-fold higher for both particles compared to docetaxel. Additionally, the volume of distribution (Vd) of Docetaxel in PRINT formulations was ~18-fold (PRINT-Doc-80×320) and ~33-fold (PRINT-Doc-200×200) lower than Docetaxel. The prolonged duration of Docetaxel in plasma when dosed with PRINT formulations subsequently lead to increased tumor exposure of Docetaxel from 0-168 hours (~53% higher for PRINT-Doc-80×320 and ~76% higher for PRINT-Doc-200×200 particles). PRINT-Doc-80×320 had lower exposures in the liver, spleen and lung compared with PRINT-Doc-200×200. Thus, the use of particles with smaller feature size may be preferred to decrease clearance by organs of the mononuclear phagocyte system