Dextran-coated superparamagnetic iron oxide nanoparticles (DSPIONs) have gained considerable interest, because of their biocompatibility and biosafety in clinics. Doxorubicin (Dox), a widely used chemotherapeutic drug, always has limited applications in clinical therapy due to its serious side effects of dose-limiting irreversible cardiotoxicity and myelo suppression. Herein, DSPIONs were synthesized and developed as magnetic carriers for doxorubicin. The Dox–DSPION conjugates were evaluated in the in vitro test of Dox release, which showed pH-dependence with the highest release percentage of 50.3% at pH 5.0 and the lowest release percentage of 11.8% in a physiological environment. The cytotoxicity of DSPIONs and Dox–DSPIONs evaluated by the MTT assay indicated that DSPIONs had no cytotoxicity and the conjugates had significantly reduced the toxicity (IC₅₀ = 1.36 μg mL⁻¹) compared to free Dox (IC₅₀ = 0.533 μg mL⁻¹). Furthermore, confocal microscopic data of cell uptake suggest that less cytotoxicity of Dox–DSPIONs may be attributed to the cellular internalization of the conjugates and sustainable release of Dox from the formulation in the cytoplasm. More importantly, the results from the rabbit VX2 liver tumor model test under an external magnetic field showed that the conjugates had approximately twice the anti-tumor activity and two and a half times the animal survival rate, respectively, compared to free Dox. Collectively, our data have demonstrated that Dox–DSPIONs have less toxicity with better antitumor effectiveness in in vitro and in vivo applications, suggesting that the conjugates have potential to be developed into chemo-therapeutic formulations.

In this communication, we present a facile solvothermal method to prepare single crystal Fe₃O₄ nanorods with a tunable aspect ratio (length from 58 to 250 nm, width from 8 to 64 nm). Then the as-prepared oleic acid-capped hydrophobic nanorods were transferred into water phase by oxidation and decomposition of oleic acid with sodium periodate. The water-phased nanorods could be acquired without any changes in morphology and crystallinity.

Current techniques for single nucleotide polymorphism (SNP) detection require tedious experimental procedures and expensive and sophisticated instruments. In this study, a visual genotyping method has been successfully established via combining ARMS-PCR with gold magnetic nanoparticle (GoldMag)-based lateral flow assay (LFA) and applied to the genotyping of methylenetetrahydrofolate reductase (MTHFR) C677T. C677T substitution of the gene MTHFR leads to an increased risk of diseases. The genotyping result is easily achievable by visual observation within 5 minutes after loading of the PCR products onto the LFA device. The system is able to accurately assess a broad detection range of initial starting genomic DNA amounts from 5 ng to 1200 ng per test sample. The limit of detection reaches 5 ng. Furthermore, our PCR-LFA system was applied to clinical trials for screening 1721 individuals for the C677T genotypes. The concordance rate of the genotyping results detected by PCR-LFA was up to 99.6% when compared with the sequencing results. Collectively, our PCR-LFA has been proven to be rapid, accurate, sensitive, and inexpensive. This new method is highly applicable for C677T SNP screening in laboratories and clinical practices. More promisingly, it could also be extended to the detection of SNPs of other genes.