Search

Hollow magnetic polymeric particles (HoMPs) with controllable location of magnetic nanoparticles and functionality of polymeric double shell were fabricated by means of the facile soft templating method in one-pot. During the in situ miniemulsion polymerization, hexadecane, the Ostwald suppressing agent, acted as a soft template, which later formed a controllable void size. Adjusting ratio and polarity of monomers caused the difference in polymerization kinetics and phase separation, which resulted in HoMPs with two internal architectures, i.e., HoMPs-I with magnetic at the inner shell/void interface and HoMPs-II with magnetic-embedded shell. Both HoMPs-I and II contained high magnetic content (30-50%wt) with sufficient saturation magnetization (16-30 emu/g). With large void volume (>50%) and distinct shell polarity, either hydrophilic Rhodamine B or hydrophobic fluorescein isothiocyanate dye was selectively loaded. After functionalization with a cancer cell targeting ligand, folic acid (FA), the cellular uptake of HoMPs-FA in HeLa cell was improved with 100% cell viability and without cell destruction. This fabrication method provides a facile mean to tailor surface chemistry and architectures of hollow hybrid particles, which would be potentially used for efficient treatment of cancer tumors., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: Magnetic nanoparticles (MNPs) have been widely used in medical diagnostic research. In this work, two technologies, MNPs and polymerase chain reaction (PCR), were combined to increase detection sensitivity and specificity. A novel technique based on the MNPs-PCR enzyme-linked gene assay (MELGA) was developed for detection of the BCR/ABL abnormal gene in chronic myelogenous leukemia (CML) patients., Methods: An MNPs-labeled BCR forward primer and a biotin-labeled ABL reverse primer were used to specifically amplify the target gene. After magnetic separation, the PCR product bound to MNPs labeled with streptavidin-conjugated horseradish peroxidase was incubated with the peroxidase substrate and hydrogen peroxide to generate the colorimetric signal., Results: When compared with real-time quantitative-PCR (RQ-PCR), the MELGA technique exhibited an increased sensitivity of <1 fg with high specificity for the BCR/ABL fusion gene in CML patients. In addition, MELGA colorimetric results correlated well with the number of copies obtained from RQ-PCR., Conclusion: This simple and cost-effective technique is suitable for monitoring CML patients during targeted therapy (tyrosine kinase inhibitors) especially in rural hospitals., (© 2015 Wiley Periodicals, Inc.)

Mesenchymal stem cells (MSCs) are a type of adult stem cell that contains multi-differentiation and proliferative properties and that shows high treatment implications for many clinical problems. The outcome of stem cell transplantation is still limited due to many factors, especially their survival and their interaction with the microenvironment after transplantation. Molecular imaging is a challenging technique that has been used to overcome this limitation and is based on the concept of labeling cells with tractable, visible, and non-toxic materials to track the cells after transplantation. In this study, magnetic polymeric nanoparticles (MPNPs) were used to directly label Wharton's jelly-derived MSCs (WJ-MSCs). After labeling, the growth rate and the viability of the MSCs as well as the time of exposure were determined. The 3D images of WJ-MSCs labeled with MPNPs for 24 h were created using confocal microscopy. The results showed that, after incubation with fluorescent MPNPs for over 8 h, the growth rate and cell viability of the WJ-MSCs was similar to those of the control. Three-dimensional imaging revealed that the fluorescent MPNPs could infiltrate into the cells and spread into the cytoplasm, which suggests that the synthesized fluorescent MPNPs could possibly label MSCs for cell tracking study and be further developed for in vivo applications.

The simple and less expensive technique based on magnetic nanoparticles (MNPs) was developed for separation of malaria parasites containing specific antigens. The carboxylated MNPs were chemically bound with anti-P. falciparum IgG antibodies (Ab-MNPs) purified from the plasma of malaria patients and then used for removal of P. falciparum malaria-infected erythrocytes from other non-infected blood cells in malaria culture at a given percent parasitemia. The results from optical microscope showed that all blood stages parasites, i.e., ring, trophozoite and schizont, could be separated from other blood components with high purity (> or = 95%) and yield of 33.5% (the early stages of ring and trophozoite:the schizont stage were 1:1.34). Highly specific interaction between Ab-MNPs and the P. falciparum malaria infected erythrocytes was confirmed by scanning electron microscope. When compared to the centrifugation with Percoll gradient and depletion by sorbitol lysis which are specific to the mature and the ring stages, respectively, our technique would be more useful for production of high quality of parasites to use in malaria pathogenesis or immunological studies, and in detection techniques.

A novel and sensitive magnetic polymeric nanoparticle (MPNP)-polymerase chain reaction-colorimetry (magneto-PCR-colorimetry) technique was developed for detection of Vibrio cholerae ( V. cholerae ). The technique involved an amplification of V. cholerae DNA on the surface of an MPNP and then employed the intrinsic catalytic activity of the MPNP to detect the target gene by colorimetry. An amino-modified forward primer was covalently labeled onto the MPNP surface which would bind to PCR product during PCR cycling. By employing the catalytic activity of the MPNP, the analysis of PCR product bound MPNP yielded a sensitivity of 10(3) CFU/mL of V. cholerae in buffer system within 4 h. The specificity and efficiency of the technique were investigated by using various bacterial DNAs in drinking and tap water.