Preparation of Magnetite Nanoparticles Coated with an Amphiphilic Block Copolymer: A Potential Drug Carrier with a Core-Shell-Corona Structure for Hydrophobic Drug Delivery

Nanotechnology in Colorectal Cancer for Precision Diagnosis and Therapy

Colorectal cancer (CRC) is the third most frequently occurring tumor in the human population. CRCs are usually adenocarcinomatous and originate as a polyp on the inner wall of the colon or rectum which may become malignant in the due course of time. Although the therapeutic options of CRC are limited, the early diagnosis of CRC may play an important role in preventive and therapeutic interventions to decrease the mortality rate. The CRC-affected tissues exhibit several molecular markers that may be exploited as the novel strategy to develop newer approaches for the treatment of the disease. Nanotechnology consists of a wide array of innovative and astonishing nanomaterials with both diagnostics and therapeutic potential. Several nanomaterials and nano formulations such as Carbon nanotubes, Dendrimer, Liposomes, Silica Nanoparticles, Gold nanoparticles, Metal-organic frameworks, Core-shell polymeric nano-formulations, Nano-emulsion System, etc can be used to targeted anticancer drug delivery and diagnostic purposes in CRC. The light-sensitive photosensitizer drugs loaded gold and silica nanoparticles can be used to diagnose as well as the killing of CRC cells by the targeted delivery of anticancer drugs to cancer cells. This review is focused on the recent advancement of nanotechnology in the diagnosis and treatment of CRC.

Hybrid photosensitizer based on amphiphilic block copolymer stabilized silver nanoparticles for highly efficient photodynamic inactivation of bacteria

We report the development of a type of novel hybrid photosensitizers for photodynamic inactivation of broad-spectrum bacteria.

Temperature- and redox-responsive magnetic complex micelles for controlled drug release

PCL-SS-PDMAEMA/Fe₃O₄ magnetic complex micelles can present dual temperature- and redox-responses, magnetism and magnetothermal properties.

Fabrication of docetaxel surfaced Fe3O4 magnetite nanoparticles and their cytotoxicity on 4 T1 breast cancer cells

Background

In the recent years, there is an increasing attention to the using of Fe₃O₄ magnetite nanoparticles (MNPs) as drug delivery systems. Application of this nanoparticles could profit advantages of nanomedicine to enhance biological activity of pharmaceutical ingredients.

Methods

Fe₃O₄ MNPs were synthesised by a chemical method and characterized by transmission electron microscopy and energy-dispersive spectroscopy techniques. In the next step, docetaxel-coated Fe₃O₄ MNPs were prepared, using percipitation method. The surface chemistry of docetaxel-coated Fe₃O₄ MNPs as well as their thermal decomposition characteristics were examined using fourier transform infrared spectroscopy and thermogravimetric analyzer equipment, respectively. The cytotoxicity assay was conducted on 4 T1 breast cancer carsinoma by MTT assay to evaluate the possible in vitro antiproliferative effects of docetaxel-coated Fe₃O₄ MNPs.

Results

During precipitation process, docetaxel molecules were precipitated on the surface of Fe₃O₄ MNPs by the ratio of 3:100 w/w which indicates that each milligram of coated Fe₃O₄ MNPs averagely contained 30 μg pure docetaxel compound. Docetaxel showed aniproliferative effects against mentioned cell line. The higestest concentartion of docetaxel (80 μg/ml) caused about 80% cell death. However, the results demostarted that much lower amounts of docetaxel will be needed in combination of Fe₃O₄ MNPs to produce the potent antiproliferative effect compared to docetaxel alone. Dose response cytotoxicity assay of docetaxel-coated Fe₃O₄ MNPs against 4 T1 breast cancer cells showed that lower amount of docetaxel (0.6 μg/ml) can exhibit higher cytotoxic effect against this cancer cell line (90% cell death).

Magnetite-loaded fluorine-containing polymeric micelles for magnetic resonance imaging and drug delivery

Magnetite (Fe(3)O(4)) - loaded polymer micelles (denoted as "magnetomicelles") are produced by self-assembly of fluorine-containing amphiphilic poly(HFMA-g-PEGMA) copolymers with oleic acid modified Fe(3)O(4) nanoparticles in an aqueous medium. The oleic acid modified Fe(3)O(4) nanoparticles form small clusters in the poly(HFMA-g-PEGMA) micelles with a mean diameter of 100 nm and the magnetomicelles show high stability in an aqueous medium due to the high hydrophobic fluorine segments in graft copolymers enhance the stability of the micelles. The magnetomicelles also show good cytocompatibility based on the MTT cytotoxicity assay and possess paramagnetic properties with saturation magnetization of 17.14 emu/g.Their good stability, cytocompatibility, and paramagnetic properties render the materials attractive in drug delivery and in vivo magnetic resonance imaging (MRI) applications. Controlled release of hydrophobic drug-5-fluorouracil is achieved from the magnetomicelles with a loading efficiency of 20.94 wt%. The magnetomicelles have transverse relaxivity rates (r(2)) of 134.27 mM(-1) s(-1) and exhibit high efficacy as a negative MRI agent in T(2)-weighted imaging. In vivo MRI studies demonstrate that the contrast between liver and spleen is enhanced by the magnetomicelles. These favorable properties suggest clinical use as nanocarriers in drug delivery applications and contrast agents in MRI.