Bifunctional Magnetic Nanoparticles Research Articles

Smart Magnetic Nanocarriers for Codelivery of Nitric Oxide and Doxorubicin for Enhanced Apoptosis in Cancer Cells.

Extremely short half-life therapeutic molecule nitric oxide (NO) plays significant roles in the functioning of various physiological and pathological processes in the human body, whereas doxorubicin hydrochloride (DOX) is a clinically important anticancer drug widely used in cancer chemotherapy. Thus, the intracellular delivery of these therapeutic molecules is tremendously important to achieve their full potential. Herein, we report a novel approach for the development of highly water-dispersible magnetic nanocarriers for codelivery of NO and DOX. Primarily, bifunctional magnetic nanoparticles enriched with carboxyl and thiol groups were prepared by introducing cysteine onto the surface of citrate-functionalized Fe3O4 nanoparticles. DOX was electrostatically conjugated onto the surface of bifunctional nanoparticles via carboxyl moieties, whereas the thiol group was further nitrosated to provide NO-releasing molecules. The developed magnetic nanocarrier exhibited good aqueous colloidal stability, protein resistance behavior, and high encapsulation efficacy for NO (65.5%) and DOX (85%), as well as sustained release characteristics. Moreover, they showed superior cytotoxicity toward cancer (A549 and MCF-7) cells via apoptosis induction over normal (WI26VA4) cells. Specifically, we have developed magnetic nanocarriers having the capability of dual delivery of NO and DOX, which holds great potential for combinatorial cancer treatment.

Magneto-assisted enzymatic DNA walkers for simultaneous electrochemical detection of amyloid-beta oligomers and Tau.

DNA walkers have been widely explored and applied as biosensor elements to detect disease-related biomarkers. Traditional interface-anchored DNA walkers typically have a fixed swing arm range and an orientation of the preset track, which might complicate the design of a sensor system and limit its application in more scenes. We propose a simple electrochemical aptasensor to accurately detect Alzheimer's disease (AD) based on a nicking enzyme-powered DNA walker. In this method, bifunctional magnetic nanoparticles are used to identify and capture Aβ oligomers (AβO) and Tau and release the DNA walker. As the DNA walker moves freely on the surface of the electrode, the nicking enzymes circularly cleave and release the two signal substrate chains, significantly amplifying the signal. It has been demonstrated that the constructed sensor can sensitively detect AβO and Tau, and the combined analysis of dual markers improves the accuracy of AD diagnosis. Furthermore, this method can distinguish normal individuals from AD patients in real cerebrospinal fluid samples. The excellent performance of this biosensor makes it promising for clinical applications in diagnosing AD patients and prognosis assessment.

Multifunctional Fe3O4@SiO2-CDs magnetic fluorescent nanoparticles as effective carrier of gambogic acid for inhibiting VX2 tumor cells

This paper reports a dual-functional platform that can be used for synergistic therapy, including drug release and magnetic targeting. The platform is realized through an amide reaction between high-fluorescence carbon quantum dots (CD) prepared by microwave method and amino-functional Fe3O4@SiO2 with high saturation magnetic strength and a core-shell structure to obtain multifunctional magnetic fluorescent nanocomposite particles Fe3O4@SiO2-CDs. The structure, drug release behavior, cytotoxicity, fluorescence and distribution in vivo of Fe3O4@SiO2-CDs nanoparticles were studied. The results show that the Fe3O4@SiO2-CDs with a dynamic diameter of about 155.0 nm and a magnetic saturation intensity of 31.2 emu/g has a higher loading of gambogic acid (GA), and is more conducive to drug release in an environment of pH = 5.7. In addition, Fe3O4@SiO2-CDs has low cytotoxicity and can enter VX2 cells. However, GA-loaded Fe3O4@SiO2-CDs has an inhibitory effect on VX2 cells, and the cell survival rate is less than 20% at a concentration of 100 μg/mL. Magnetic targeting experiments show that bifunctional magnetic nanoparticles have an outstanding magnetic targeting effect on tumors.

Bifunctional magnetic nanoparticles for efficient cholesterol detection and elimination via host-guest chemistry in real samples

Cholesterol is an essential compound for maintaining cellular homeostasis and human healthy. Sensitive detection of cholesterol and efficient elimination of excess cholesterol have become the essential manipulations in clinical diagnosis and health management. To date, it is still quite challenging that cholesterol detection and elimination tasks are carried out simultaneously. In this study, bifunctional magnetic nanoparticles (Fe3O4@PDA-PBA-CD) are designed and fabricated to overcome this difficulty. Taking advantages of competitive host-guest interaction and magnetic separation, highly efficient, reusable and simultaneous cholesterol detection and elimination can be achieved. The limit of detection is determined to be 4.3 nM, which is comparable or even lower than existing methods. The distinguished performance may attribute to the high loading efficiency and magnetic enrichment of nanoparticles. Besides, this efficient strategy is resistant to interfering substances, thus realizing sensitive cholesterol detection in real sample. Simultaneously, the bifunctional magnetic nanoparticles also have up to 95% cholesterol elimination efficiency, which is higher than previous reported methods. Furthermore, the nanoparticles are turned out to be reusable within 5 times without noticeable loss in cholesterol elimination efficiency. Therefore, the bifunctional magnetic nanoparticles fabricated here could hold great potential for simultaneous cholesterol detection and elimination in practical applications.

Preparation of bifunctional magnetic nanoparticles with octadecyl and phosphate groups by thiol–ene click chemistry for extraction and enrichment of organophosphorus pesticides in tea drinks

Bifunctional magnetic nanoparticles with octadecyl and phosphate groups were synthesized by thiol–ene click chemistry and applied for pre-concentration and extraction of organophosphorus pesticides (OPPs).

Bifunctional magnetic nanoparticles for analysis of aldehyde metabolites in exhaled breath of lung cancer patients

We report here the preparation of dual-functionalized magnetic nanoparticles, with the nanoparticles as extraction sorbents, a magnetic solid phase extraction method was developed and applied for the analysis of trace amount of aldehydes in human exhaled breath condensate. In the material, octyl-functionalized internal surface provided hydrophobic groups for extraction, non-ionic surfactant (Tween-20)-coated outer surface offered hydrophilic network structure to prevent the access of macromolecules, strong magnetic property of nanoparticles simplified the analytical procedure. The experimental results showed that the prepared nanoparticles exhibited good dispersibility in aqueous solution and excellent extraction efficiency toward aldehydes. Six aldehydes were derivatized with 2,4-dinitrophenylhydrazine and then the formed hydrazones were extracted by the nanoparticles and analyzed by high-performance liquid chromatography–photo diode array detector. Under the optimal conditions, the method provided low limits of detection (2.9–21.5nmolL−1), satisfactory reproducibility (relative standard deviations, 2.9–13.1%) and acceptable recoveries (73.7–133.1%). The developed method was applied successfully to determine the aldehydes metabolites in the exhaled breath condensate samples of healthy people and lung cancer patients. The dual-functionalized material is suitable for biological sample analysis. The proposed method provides an alternative approach for quantification of aldehyde metabolites in complex biological samples.

Bifunctional magnetic nanoparticles for early detection and magnetic hyperthermia cancer therapy

Magnetic hyperthermia offers promise as cancer therapy. We have tested bimetallic core/shell Fe/Fe3O4 magnetic nanoparticles (MNP) for in vivo diagnosis and targeting of MNP to tumor tissue. We have received the MNP from NanoScale Corporation. These particles have a Dopamine‐PEG layer, to which a porphyrin 'A' is attached; another porhyrin 'B' is also attached to the MNP via a peptide that represents the urokinase cleavage site. MNP were tested in B16F10 melanoma cells and neural stem cells for loading using Ferrozine assay.. For in vivo tumor detection, the MNP were injected intravenously into tumor bearing mice and fluorescence was detected after one and two days. Heat distribution studies were conducted in live mice by injecting MNP into mouse leg; temperatures were measured using a fiber optic probe. Short exposure time hyperthermia studies were conducted by exposing tumor bearing mice to alternating magnetic field (AMF) for 10 min (336KHz frequency and 5KA/m amplitude) after injecting theMNP intratumorally. MNP loaded efficiently into mouse cells with little toxicity. We detected fluorescence in tumors during laser imaging of live mice. Mouse subcutaneous melanomas were markedly attenuated; we observed 76% tumor inhibition after short exposure to AMF. These data indicate that bi‐ functional core shell MNP are effective for hyperthermia therapy and detection of subcutaneous melanoma.