Conjugation of quantum dots and Fe3O4 on carbon nanotubes for medical diagnosis and treatment

Abstract

Quantum dots (QDs) and Fe3O4 nanoparticles were conjugated onto the surfaces of carbon nanotubes (CNTs) for medical diagnosis and treatment. The nanoassembly was designed to meet the specific needs in cancer in vivo imaging and simultaneous treatment. The key functionalities needed for clinical applications were integrated, including CNT surface functionalization for attachment of biological molecules in targeting, drug storage capabilities, fluorescent emissions near the infrared range, and magnetic hyperthermia. CNT-QD-Fe3O4 developed exhibited a strong fluorescence near the infrared region for noninvasive optical in vivo imaging. Magnetization measurements showed nearly reversible hysteresis curves from CNT-QD-Fe3O4 nanoassembly. Fe3O4 conjugated CNT was found to experience hyperthermia heating under alternating electromagnetic field.

Multifunctional CNTs nanohybrids decorated with magnetic and fluorescent nanoparticles layer-by-layer

“…The obtained nanocomposites can improve or impart new optical, electrochemcal, magnetic and mechanical properties of CNTs (Morales-Cid et al 2010). Especially, CNTs nanocomposites combined with magnetic and fluorescent nanoparticles permit magnetic manipulation with simultaneous fluorescent observations (Chen et al 2010;Ruan et al 2010), which will contribute for rapid development of new therapeutic and diagnostic concepts in all the areas of medicine (Whitesides 2003;Shi 2009;Shi et al 2009;Chen et al 2010;Ruan et al 2010), such as advanced magnetic resonance imaging (MRI), guided drug, gene delivery (Ruan et al 2010), magnetic hyperthermia, cancer therapy (Wang et al 2005;Hergt et al 2006), biosensors (Qu et al 2007;Hu et al 2008), cell tracking and bioseparation (Shubayev et al 2009) and the therapy for oncology and infectious diseases (Prato et al 2008), etc. Moreover, it still remains a tremendous challenge to find a simple and effective approach for the manufacture of magnetic-fluorescent nanohybrids.…”

Engineered Multifunctional Nanocarriers for Cancer Diagnosis and Therapeutics

“…Combining a stable template (CNT), a highly fluorescent material (QD), and a magnetic moiety (Fe 3 O 4 ) into one signal nanocarrier would be of great medical interest as it would allow for optical diagnosis and treatment via magnetic hyperthermia. To this end, QDs and Fe 3 O 4 were attached to MWCNTs as reported by Shi et al100 Plasma polymerization was used to surface‐functionalize MWCNTs with poly(lactic– co –glycolic acid) (PLGA). PLGA is biodegradable and Food and Drug Administration‐approved for use as a polymeric drug‐delivery system.…”

“… a) Room‐temperature magnetization versus applied field for QD–Fe 3 O 4 –CNT, and b) hyperthermia temperature‐versus‐time curves for nanocarriers at different CNT:Fe 3 O 4 ratios. Reproduced with permission 100. Copyright American Institute of Physics, 2009.…”

The double-effect mechanism between Fe3O4 nanoparticles and MSA-capped CdTe QDs

“…However, many research groups [11][12][13] directly mixed Fe 3 O 4 nanoparticles and QDs to prepare the microspheres and nanotube for drug delivery and diagnostic methods. You et al and our group [14][15][16] also prepared the fluorescent magnetic nanocomposites by just mixing Fe 3 O 4 nanoparticles and CdTe QDs and found it possible to obtain stable fluorescent magnetic composite nanoparticles, and the phenomenon of fluorescent quenching by the and QDs and its effect on the fluorescence intensity of QDs are important issues, and are related to composite nanpoparticle synthesis and future applications. Herein, we investigated the interaction mechanism of CdTe QDs with Fe 3 O 4 in detail.…”