Preparation, characterization, in vivo and in vitro studies of arsenic trioxide Mg-Fe ferrite magnetic nanoparticles

Chemoembolizing hepatocellular carcinoma with microsphere cored with arsenic trioxide microcrystal

Chemoembolization for hepatocellular carcinoma (HCC) is often suboptimal due to multiple involved signaling and lack of effective drugs. Arsenic trioxide (ATO) is a potent chemotherapeutic agent, which can target multiple signaling and have substantial efficacy on HCC. However, its usage is limited due to systemic toxicity. Using ATO-eluting beads/microspheres for chemoembolization can have locoregional drug delivery and avoid systemic exposure but will require high drug load, which has not been achieved due to low solubility of ATO. Through an innovative approach, we generated the transiently formed ATO microcrystals via micronization and stabilized these microcrystals by solvent exchange. By encapsulating ATO microcrystals, but not individual molecules, with poly(lactide-co-glycolic acid) (PLGA), we developed microspheres cored with extremely high dense ATO. The molar ratio between ATO and PLGA was 157.4:1 and drug load was 40.1%, which is 4–20 fold higher than that of reported ATO nano/microparticles. These microspheres sustainably induced reactive oxygen species, apoptosis, and cytotoxicity on HCC cells and reduced tumor growth by 80% via locoregional delivery. Chemoembolization on mice model showed that ATO-microcrystal loaded microspheres, but not ATO, inhibited HCC growth by 60–75%, which indicates ATO within these microspheres gains the chemoembolizing function via our innovative approach.

In Vitro and In Vivo Models for Evaluating the Oral Toxicity of Nanomedicines

Toxicity studies for conventional oral drug formulations are standardized and well documented, as required by the guidelines of administrative agencies such as the US Food & Drug Administration (FDA), the European Medicines Agency (EMA) or European Medicines Evaluation Agency (EMEA), and the Japanese Pharmaceuticals and Medical Devices Agency (PMDA). Researchers tend to extrapolate these standardized protocols to evaluate nanoformulations (NFs) because standard nanotoxicity protocols are still lacking in nonclinical studies for testing orally delivered NFs. However, such strategies have generated many inconsistent results because they do not account for the specific physicochemical properties of nanomedicines. Due to their tiny size, accumulated surface charge and tension, sizeable surface-area-to-volume ratio, and high chemical/structural complexity, orally delivered NFs may generate severe topical toxicities to the gastrointestinal tract and metabolic organs, including the liver and kidney. Such toxicities involve immune responses that reflect different mechanisms than those triggered by conventional formulations. Herein, we briefly analyze the potential oral toxicity mechanisms of NFs and describe recently reported in vitro and in vivo models that attempt to address the specific oral toxicity of nanomedicines. We also discuss approaches that may be used to develop nontoxic NFs for oral drug delivery.

Synthesis and cytotoxicity study of magnesium ferrite-gold core-shell nanoparticles

In this work, the core-magnesium ferrite (MgFe2O4) nanoparticles were prepared by hydrothermal technique. Completed gold (Au) shell coating on the surfaces of MgFe2O4 nanoparticles was obtained by varying core/shell ratios via a reduction method. Phase identification, morphological evolution, optical properties, magnetic properties and cytotoxicity to mammalian cells of these MgFe2O4 core coated with Au nanoparticles were examined by using a combination of X-ray diffraction, scanning electron microscopy, transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy, UV-visible spectroscopy (UV-vis), vibrating sample magnetometry and resazurin microplate assay techniques. In general, TEM images revealed different sizes of the core-shell nanoparticles generated from various core/shell ratios and confirmed the completed Au shell coating on MgFe2O4 core nanoparticles via suitable core/shell ratio with particle size less than 100 nm. The core-shell nanoparticle size and the quality of coating influence the optical properties of the products. The UV-vis spectra of complete coated MgFe2O4-Au core-shell nanoparticles exhibit the absorption bands in the near-Infrared (NIR) region indicating high potential for therapeutic applications. Based on the magnetic property measurement, it was found that the obtained MgFe2O4-Au core-shell nanoparticles still exhibit superparamagnetism with lower saturation magnetization value, compared with MgFe2O4 core. Both of MgFe2O4 and MgFe2O4-Au core-shell also showed in vitro non-cytotoxicity to mouse areola fibroblast (L-929) cell line.

Microbial synthesis of poly-3-hydroxybutyrate and its application as targeted drug delivery vehicle

Arsenic trioxide loaded biocompatible PHB-PVA(1) nanoparticles (<100 nm in size) with folate functionalized surface were synthesized using poly-[(R)-3-hydroxybutyric acid] (PHB) produced by Bacillus firmus NII 0830. Folate functionalization was carried using dicyclohexyl carbodiimide (DCC) as a catalyst and 10-bromodecanol as a linker to conjugate glutamic acid terminal of folate with the hydroxylate groups present on the surface of PHBA-PVA(2) nanotrojans. The effect of fabrication parameters on shape, size distribution and PDI of the PHB nanoparticles were also investigated. It was observed that increase in sonication time and polyvinyl alcohol (PVA) concentration greatly reduced the size of nanoparticles. The drug release studies on arsenic trioxide incorporated PHB-PVA nanoparticles were conducted at physiological pH and temperature. FOL-PHBA-PVA(3) nanoparticles showed greater extent of cytotoxicity towards murine fibrosarcoma L929 cells than PHBA-PVA nanoparticles alone without conjugated folate, indicating the significance of folate as ligand for specific targeting of FR+ cancer cells.

Cytotoxicity of nickel zinc ferrite nanoparticles on cancer cells of epithelial origin

In this study, in vitro cytotoxicity of nickel zinc (NiZn) ferrite nanoparticles against human colon cancer HT29, breast cancer MCF7, and liver cancer HepG2 cells was examined. The morphology, homogeneity, and elemental composition of NiZn ferrite nanoparticles were investigated by scanning electron microscopy, transmission electron microscopy, and energy dispersive X-ray spectroscopy, respectively. The exposure of cancer cells to NiZn ferrite nanoparticles (15.6–1,000 μg/mL; 72 hours) has resulted in a dose-dependent inhibition of cell growth determined by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The quantification of caspase-3 and -9 activities and DNA fragmentation to assess the cell death pathway of the treated cells showed that both were stimulated when exposed to NiZn ferrite nanoparticles. Light microscopy examination of the cells exposed to NiZn ferrite nanoparticles demonstrated significant changes in cellular morphology. The HepG2 cells were most prone to apoptosis among the three cells lines examined, as the result of treatment with NiZn nanoparticles. In conclusion, NiZn ferrite nanoparticles are suggested to have potential cytotoxicity against cancer cells.

Magnetic nanovectors for drug delivery

Nanotechnology holds the promise of novel and more effective treatments for vexing human health issues. Among these are the use of nanoparticle platforms for site-specific delivery of therapeutics to tumors, both by passive and active mechanisms; the latter includes magnetic vectoring of magnetically responsive nanoparticles (MNP) that are functionalized to carry a drug payload that is released at the tumor. The conceptual basis, which actually dates back a number of decades, resides in physical (magnetic) enhancement, with magnetic field gradients aligned non-parallel to the direction of flow in the tumor vasculature, of existing passive mechanisms for extravasation and accumulation of MNP in the tumor interstitial fluid, followed by MNP internalization. In this review, we will assess the most recent developments and current status of this approach, considering MNP that are composed of one or more of the three elements that are ferromagnetic at physiological temperature: nickel, cobalt and iron. The effects on cellular functions in vitro, the ability to successfully vector the platform in vivo, the anti-tumor effects of such localized nano-vectors, and any associated toxicities for these MNP will be presented. The merits and shortcomings of nanomaterials made of each of the three elements will be highlighted, and a roadmap for moving this long-established approach forward to clinical evaluation will be put forth.

Magnetic nanovectors for drug delivery

Nanotechnology holds the promise of novel and more effective treatments for vexing human health issues. Among these are the use of nanoparticle platforms for site-specific delivery of therapeutics to tumors, both by passive and active mechanisms; the latter includes magnetic vectoring of magnetically responsive nanoparticles (MNP) that are functionalized to carry a drug payload that is released at the tumor. The conceptual basis, which actually dates back a number of decades, resides in physical (magnetic) enhancement, with magnetic field gradients aligned non-parallel to the direction of flow in the tumor vasculature, of existing passive mechanisms for extravasation and accumulation of MNP in the tumor interstitial fluid, followed by MNP internalization. In this review, we will assess the most recent developments and current status of this approach, considering MNP that are composed of one or more of the three elements that are ferromagnetic at physiological temperature: nickel, cobalt and iron. The effects on cellular functions in vitro, the ability to successfully vector the platform in vivo, the anti-tumor effects of such localized nano-vectors, and any associated toxicities for these MNP will be presented. The merits and shortcomings of nanomaterials made of each of the three elements will be highlighted, and a roadmap for moving this long-established approach forward to clinical evaluation will be put forth.