In the current research, we present a single-step, one-pot, room temperature green synthesis approach for the development of functional poly(tannic acid)-based silver nanocomposites. Silver nanocomposites were synthesized using only tannic acid (plant polyphenol) as a reducing and capping agent. At room temperature and under mildly alkaline conditions, tannic acid reduces the silver salt into nanoparticles. Tannic acid undergoes oxidation and self-polymerization before the encapsulating of the synthesized silver nanoparticle and forms silver nanocomposites with a thick capping layer of poly(tannic acid). No organic solvents, special instruments, or toxic chemicals were used during the synthesis process. The results for the silver nanocomposites prepared under optimum conditions confirmed the successful synthesis of nearly spherical and fine nanocomposites (10.61 ± 1.55 nm) with a thick capping layer of poly(tannic acid) (~3 nm). With these nanocomposites, iron could be detected without any special instrument or technique. It was also demonstrated that, in the presence of Fe3+ ions (visual detection limit ~20 μM), nanocomposites aggregated using the coordination chemistry and exhibited visible color change. Ultraviolet-visible (UV-vis) and scanning electron microscopy (SEM) analysis also confirmed the formation of aggregate after the addition of the analyte in the detection system (colored nanocomposites). The unique analytic performance, simplicity, and ease of synthesis of the developed functional nanocomposites make them suitable for large-scale applications, especially in the fields of medical, sensing, and environmental monitoring. For the medical application, it is shown that synthesized nanocomposites can strongly inhibit the growth of Escherichia coli and Staphylococcus aureus. Furthermore, the particles also exhibit very good antifungal and antiviral activity.

• Keywords
• antibacterial, antifungal, antiviral activity, green synthesis, poly(tannic acid), silver nanocomposites, visual detection of ferric,
• Publication type
• Journal Article MeSH

In vitro labeling of pancreatic islets with iron nanoparticles enables their direct posttransplant visualization by magnetic resonance; however, there is still a discrepancy in the fate of iron nanoparticles. This study was performed to detail the labeling process, consequently to improve the labeling efficacy and to confirm safety for islet cells. The islets were visible on T2*-weighted magnetic resonance images as hypointense spots immediately after 1-hr cultivation. Although at this time already the sufficient superparamagnetic effect was achieved, most of the particles were deposed in islet macrophages and only later were they found in endosomes of endocrine islet cells. The iron content depended on length of culture period. The labeled islets showed an intact ultrastructure, responded normally to glucose stimulation in vitro, and were able to treat experimental diabetes. For purpose of subsequent magnetic resonance imaging, a 24-hr culture with ferucarbotran leads to sufficient labeling with no apparent adverse effect on beta cell morphology or function.

• MeSH
• Staining and Labeling methods   MeSH
• Insulin-Secreting Cells pathology   MeSH
• Time Factors MeSH
• Metal Nanoparticles * MeSH
• Rats MeSH
• Cells, Cultured MeSH
• Islets of Langerhans pathology   MeSH
• Magnetic Resonance Imaging methods   MeSH
• Macrophages pathology   MeSH
• Islets of Langerhans Transplantation methods   MeSH
• Ferric Compounds * MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• ferric oxide MeSH Browser
• Ferric Compounds * MeSH

Magnetic resonance imaging (MRI) of superparamagnetic iron oxide-labeled cells can be used as a non-invasive technique to track stem cells after transplantation. The aim of this study was to (1) evaluate labeling efficiency of D-mannose-coated maghemite nanoparticles (D-mannose(γ-Fe2O3)) in neural stem cells (NSCs) in comparison to the uncoated nanoparticles, (2) assess nanoparticle utilization as MRI contrast agent to visualize NSCs transplanted into the mouse brain, and (3) test nanoparticle biocompatibility. D-mannose(γ-Fe2O3) labeled the NSCs better than the uncoated nanoparticles. The labeled cells were visualized by ex vivo MRI and their localization subsequently confirmed on histological sections. Although the progenitor properties and differentiation of the NSCs were not affected by labeling, subtle effects on stem cells could be detected depending on dose increase, including changes in cell proliferation, viability, and neurosphere diameter. D-mannose coating of maghemite nanoparticles improved NSC labeling and allowed for NSC tracking by ex vivo MRI in the mouse brain, but further analysis of the eventual side effects might be necessary before translation to the clinic.

• Keywords
• brain, maghemite, magnetic resonance imaging, mouse, nanoparticles, neural stem cells,
• MeSH
• Cell Tracking methods   MeSH
• Magnetic Resonance Imaging methods   MeSH
• Magnetite Nanoparticles chemistry   MeSH
• Mannose chemistry   MeSH
• Brain cytology   MeSH
• Mice, Inbred C57BL MeSH
• Mice MeSH
• Neural Stem Cells cytology   transplantation   MeSH
• Ferric Compounds chemistry   MeSH
• Animals MeSH
• Check Tag
• Mice MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• ferric oxide MeSH Browser
• Magnetite Nanoparticles MeSH
• Mannose MeSH
• Ferric Compounds MeSH

Due to its native origin, excellent biocompatibility and biodegradability, hyaluronan (HA) represents an attractive polymer for superparamagnetic iron oxide nanoparticles (SPION) coating. Herein, we report HA polymeric micelles encapsulating oleic acid coated SPIONs, having a hydrodynamic size of about 100 nm and SPION loading capacity of 1-2 wt %. The HA-SPION polymeric micelles were found to be selectively cytotoxic toward a number of human cancer cell lines, mainly those of colon adenocarcinoma (HT-29). The selective inhibition of cell growth was even observed when the SPION loaded HA polymeric micelles were incubated with a mixture of control and cancer cells. The selective in vitro inhibition could not be connected with an enhanced CD44 uptake or radical oxygen species formation and was rather connected with a different way of SPION intracellular release. While aggregated iron particles were visualized in control cells, nonaggregated solubilized iron oxide particles were detected in cancer cells. In vivo SPION accumulation in intramuscular tumor following an intravenous micelle administration was confirmed by magnetic resonance (MR) imaging and histological analysis. Having a suitable hydrodynamic size, high magnetic relaxivity, and being cancer specific and able to accumulate in vivo in tumors, SPION-loaded HA micelles represent a promising platform for theranostic applications.

• MeSH
• Swiss 3T3 Cells MeSH
• Caco-2 Cells MeSH
• HCT116 Cells MeSH
• Metal Nanoparticles administration & dosage   chemistry   MeSH
• Hyaluronic Acid administration & dosage   chemistry   MeSH
• Humans MeSH
• Mesenchymal Stem Cells drug effects   MeSH
• MCF-7 Cells MeSH
• Micelles * MeSH
• Mice MeSH
• Drug Carriers administration & dosage   chemistry   MeSH
• Polymers administration & dosage   chemistry   MeSH
• Rats, Inbred BN MeSH
• Rats, Inbred Lew MeSH
• Antineoplastic Agents administration & dosage   chemistry   MeSH
• Treatment Outcome MeSH
• Xenograft Model Antitumor Assays methods   MeSH
• Ferric Compounds administration & dosage   chemistry   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• ferric oxide MeSH Browser
• Hyaluronic Acid MeSH
• Micelles * MeSH
• Drug Carriers MeSH
• Polymers MeSH
• Antineoplastic Agents MeSH
• Ferric Compounds MeSH