Beyond electrostatic interactions: Ligand shell modulated uptake of bis-conjugated iron oxide nanoparticles by cells

In vivo evaluation of toxicity and anti-inflammatory activity of iron oxide nanoparticles conjugated with ibuprofen

Aim: The low solubility and consequent poor bioavailability of ibuprofen (IBU) is a major drawback that can be overcome by anchoring IBU on ultrasmall superparamagnetic iron oxide nanoparticles (USPIONs) as effective multifunctional carriers for drug delivery. Methods: USPIONs were conjugated with glycerol phosphate (USPION-GP) and also co-conjugated with IBU (USPION-GP/IBU), and their in vivo toxicity and anti-inflammatory effects investigated. Phosphate buffer saline (control), IBU, USPION-GP and USPION-GP/IBU were intravenously administered 15 min before lipopolysaccharide-induced peritonitis in male Balb/c mice. Results: 4 h later, USPION bioconjugates did not appear to have caused toxicity to blood leukocytes or caused alterations in the spleen, liver or kidneys. Also, they inhibited lipopolysaccharide-induced neutrophil mobilization into the peritoneum. Conclusion: The absence of systemic toxicity and the unexpected anti-inflammatory action of USPION bioconjugates indicates that they could be a novel and effective approach to administer IBU and warrant further investigation.

Phosphotungstic acid impregnated niobium coated superparamagnetic iron oxide nanoparticles as recyclable catalyst for selective isomerization of terpenes

Conversion efficiency as high as 80-100% and 50% selectivity for camphene and limonene was achieved with low production of polymeric byproducts (18-28%), easy recovery with a magnet and reuse for up to five cycles maintaining similar activity and distribution of products, using a new magnetically recyclable catalyst based on niobium oxide coated on superparamagnetic iron oxide nanoparticles (SPION) impregnated with phosphotungstic acid (HPW). The catalyst was demonstrated to be effective in the selective conversion of alpha and beta-pinenes into valuable terpenes, under ultrasonic probe activation and with toluene as solvent. A unique synergic effect between the components generating more active and selective catalytic sites was demonstrated, indicating that the SPION covered with 30 wt% of Nb2O5 gives the best performance when impregnated with HPW as co-catalyst. The materials were fully characterized by XRD, EDX, XPS, TEM, BET, VSM and FTIR.

Nitric oxide inhibition of lipopolysaccharide-stimulated RAW 247.6 cells by ibuprofen-conjugated iron oxide nanoparticles

Aim: To develop a series of superparamagnetic iron oxide nanoparticles (SPIONs) by coconjugating them with ibuprofen (ibu) and glycerol phosphate (glycerol) or ibu and glucose-1-phosphate and to assess capacity of these conjugates to inhibit the release of nitric oxide (NO) in macrophages, even at low concentrations. Materials & methods: The SPION conjugates were characterized and their properties evaluated showing the influence of those ligands on colloidal stability and inhibition of NO-release demonstrated. The cytotoxicity and possible anti-inflammatory activity were evaluated using murine macrophages (RAW 247.6). Results: SPION-glycerol phosphate/ibu conjugates inhibited the NO production induced by lipopolysaccharides, indicating a potential anti-inflammatory activity. Conclusion: SPION conjugated with ibu was shown to inhibit NO-release even at very low concentrations, suggesting possible action against inflammatory diseases.

Applications of superparamagnetic iron oxide nanoparticles in drug and therapeutic delivery, and biotechnological advancements

Superparamagnetic iron oxide nanoparticles (SPIONs) have unique properties with regard to biological and medical applications. SPIONs have been used in clinical settings although their safety of use remains unclear due to the great differences in their structure and in intra- and inter-patient absorption and response. This review addresses potential applications of SPIONs in vitro (formulations), ex vivo (in biological cells and tissues) and in vivo (preclinical animal models), as well as potential biomedical applications in the context of drug targeting, disease treatment and therapeutic efficacy, and safety studies.