Doxorubicin-modified magnetic nanoparticles as a drug delivery system for magnetic resonance imaging-monitoring magnet-enhancing tumor chemotherapy

Abstract

In this study, we developed functionalized superparamagnetic iron oxide (SPIO) nanoparticles consisting of a magnetic Fe 3 O 4 core and a shell of aqueous stable polyethylene glycol (PEG) conjugated with doxorubicin (Dox) (SPIO-PEG-D) for tumor magnetic resonance imaging (MRI) enhancement and chemotherapy. The size of SPIO nanoparticles was ~10 nm, which was visualized by transmission electron microscope. The hysteresis curve, generated with vibrating-sample magnetometer, showed that SPIO-PEG-D was superparamagnetic with an insignificant hysteresis. The transverse relaxivity ( r 2 ) for SPIO-PEG-D was significantly higher than the longitudinal relaxivity ( r 1 ) ( r 2 / r 1 >10). The half-life of Dox in blood circulation was prolonged by conjugating Dox on the surface of SPIO with PEG to reduce its degradation. The in vitro experiment showed that SPIO-PEG-D could cause DNA crosslink more serious, resulting in a lower DNA expression and a higher cell apoptosis for HT-29 cancer cells. The Prussian blue staining study showed that the tumors treated with SPIO-PEG-D under a magnetic field had a much higher intratumoral iron density than the tumors treated with SPIO-PEG-D alone. The in vivo MRI study showed that the T 2 -weighted signal enhancement was stronger for the group under a magnetic field, indicating that it had a better accumulation of SPIO-PEG-D in tumor tissues. In the anticancer efficiency study for SPIO-PEG-D, the results showed that there was a significantly smaller tumor size for the group with a magnetic field than the group without. The in vivo experiments also showed that this drug delivery system combined with a local magnetic field could reduce the side effects of cardiotoxicity and hepatotoxicity. The results showed that the developed SPIO-PEG-D nanoparticles own a great potential for MRI-monitoring magnet-enhancing tumor chemotherapy.

Magnetic and pH dual-responsive mesoporous silica nanocomposites for effective and low-toxic photodynamic therapy

“…However, after being exposed to an external magnetic field, RB-MMSNs were quickly assembled to the side near the magnet ( Figure 4B, inset). Superparamagnetic Fe 3 O 4 nanoparticles are a good T 2 contrast agent, [34][35][36] depending on the darkening effect to distinguish the contrast area with normal sites. T 2 -weighted MRI showed a concentration-dependent darkening effect, and the relaxation rate (R 2 ) of RB-MMSNs was ~52.51 S Determination of RB loading efficiency, ph-responsive release in vitro and detection of singlet oxygen…”

Effects of major parameters of nanoparticles on their physical and chemical properties and recent application of nanodrug delivery system in targeted chemotherapy

“…[2][3][4] Particularly, chemotherapy is not only one of the main therapy of cancer treatment, but also can be used as an adjuvant therapy combined with other therapies such as surgery and radiotherapy to enhance the curative effect. [5][6][7][8] But the clinical stage of tumor cannot be reflected accurately via current tumor diagnosis and pre-diagnosis, making correct and timely treatment to the patient very difficult. 9 At the meantime, drawbacks of chemotherapy have been revealed gradually: many chemotherapy drugs cannot distinguish the tumor cells and normal cells accurately, so they would attack the body's normal tissue cells along with tumor cells, thus causing intolerant side effects such as rash, alopecia, severe liver and kidney function decline, cardiotoxicity, secondary infection, bone marrow suppression (which affect the effect of chemotherapy), and the life quality of the patients seriously.…”

Mass spectrometry-based metabolomics in health and medical science: a systematic review

“…The overall objective of forensic science is to provide tools for all actors involved in criminal investigations and procedures in order to achieve fairer tracking, effective investigation of criminal science, and evidence for prosecution for or elimination from a suspected crime. 90 The characteristics of most forensic samples are complex and they are available in trace amounts. Sample types include blood, urine, saliva, faeces, tissues, etc., similar to the samples in metabolomics.…”