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Plasmonic nanoparticles are increasingly employed in several fields, thanks to their unique, promising properties. In particular, these particles exhibit a surface plasmon resonance combined with outstanding absorption and scattering properties. They are also easy to synthesize and functionalize, making them ideal for nanotechnology applications. However, the physicochemical properties of these nanoparticles can make them potentially toxic, even if their bulk metallic forms are almost inert. In this review, we aim to provide a more comprehensive understanding of the potential adverse effects of plasmonic nanoparticles in zebrafish ( Danio rerio ) during both development and adulthood, focusing our attention on the most common materials used, i.e., gold and silver.

Glaucoma and other optic neuropathies are characterized by a loss of retinal ganglion cells (RGCs), a cell layer located in the posterior eye segment. Several preclinical studies demonstrate that neurotrophins (NTs) prevent RGC loss. However, NTs are rarely investigated in the clinic due to various issues, such as difficulties in reaching the retina, the very short half-life of NTs, and the need for multiple injections. We demonstrate that NTs can be conjugated to magnetic nanoparticles (MNPs), which act as smart drug carriers. This combines the advantages of the self-localization of the drug in the retina and drug protection from fast degradation. We tested the nerve growth factor and brain-derived neurotrophic factor by comparing the neuroprotection of free versus conjugated proteins in a model of RGC loss induced by oxidative stress. Histological data demonstrated that the conjugated proteins totally prevented RGC loss, in sharp contrast to the equivalent dose of free proteins, which had no effect. The overall data suggest that the nanoscale MNP-protein hybrid is an excellent tool in implementing ocular drug delivery strategies for neuroprotection and therapy.

Background: Diabetic retinopathy (DR) is a major complication of diabetes, characterized by extensive vascular pathology leading to vision loss. Neuronal suffering and death are also present in the diabetic retina as a result of different molecular mechanisms that are compromised or modified in response to high glucose. The aim of this paper is to highlight recent data indicating that neurodegeneration is likely to play a primary role in the development of DR and that strategies based on nanomedicine may be exploited to deliver neuroprotection to the retina., Methods: An extensive analysis of the publications dealing with the role of neuroprotection in DR and with nanoparticle-mediated drug delivery to the retina has been conducted using PubMed, with particular attention to the most recent papers., Results: There are important limitations related to possible systemic side effects of neuroprotective substances and to drug bioavailability in the retina such as, for instance, the amount of drug reaching the retina, the need of keeping to a minimum the number of administrations (especially, for example, in the case of intraocular injections) and the need of assuring a long-lasting, graded intraocular drug delivery. In recent years, a variety of investigations have been aimed at the exploitation of approaches of nanomedicine to enhance the pharmacokinetics and pharmacodynamic activity of intraocularly delivered drugs. In particular, we provide some preliminary results that we have obtained about the feasibility of delivering magnetic nanoparticles functionalized with a neuroprotectant to mouse eyes through intraocular injections., Conclusion: We propose that nanoparticles functionalized with neuroprotective substances may be used to protect the diabetic retina, thus causing an impact in the design of future pharmacologic treatments for DR., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

One of the mechanisms responsible for cancer-induced increased blood supply in malignant neoplasms is the overexpression of vascular endothelial growth factor (VEGF). Several antibodies for VEGF targeting have been produced for both imaging and therapy. Molecularly imprinted polymer nanoparticles, nanoMIPs, however, offer significant advantages over antibodies, in particular in relation to improved stability, speed of design, cost and control over functionalization. In the present study, the successful production of nanoMIPs against human VEGF is reported for the first time. NanoMIPs were coupled with quantum dots (QDs) for cancer imaging. The composite nanoparticles exhibited specific homing toward human melanoma cell xenografts, overexpressing hVEGF, in zebrafish embryos. No evidence of this accumulation was observed in control organisms. These results indicate that nanoMIPs are promising materials which can be considered for advancing molecular oncological research, in particular when antibodies are less desirable due to their immunogenicity or long production time.

There is a growing body of evidence indicating the importance of physical stimuli for neuronal growth and development. Specifically, results from published experimental studies indicate that forces, when carefully controlled, can modulate neuronal regeneration. Here, we validate a non-invasive approach for physical guidance of nerve regeneration based on the synergic use of magnetic nanoparticles (MNPs) and magnetic fields (Ms). The concept is that the application of a tensile force to a neuronal cell can stimulate neurite initiation or axon elongation in the desired direction, the MNPs being used to generate this tensile force under the effect of a static external magnetic field providing the required directional orientation. In a neuron-like cell line, we have confirmed that MNPs direct the neurite outgrowth preferentially along the direction imposed by an external magnetic field, by inducing a net angle displacement (about 30°) of neurite direction. From the clinical editor: This study validates that non-invasive approaches for physical guidance of nerve regeneration based on the synergic use of magnetic nanoparticles and magnetic fields are possible. The hypothesis was confirmed by observing preferential neurite outgrowth in a cell culture system along the direction imposed by an external magnetic field., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Nanoparticles (NPs) show new characteristics compared to the corresponding bulk material. These nanoscale properties make them interesting for various applications in biomedicine and life sciences. One field of application is the use of magnetic NPs to support regeneration in the nervous system. Drug delivery requires a functionalization of NPs with bio-functional molecules. In our study, we functionalized self-made PEI-coated iron oxide NPs with nerve growth factor (NGF) and glial cell-line derived neurotrophic factor (GDNF). Next, we tested the bio-functionality of NGF in a rat pheochromocytoma cell line (PC12) and the bio-functionality of GDNF in an organotypic spinal cord culture. Covalent binding of NGF to PEI-NPs impaired bio-functionality of NGF, but non-covalent approach differentiated PC12 cells reliably. Non-covalent binding of GDNF showed a satisfying bio-functionality of GDNF:PEI-NPs, but turned out to be unstable in conjugation to the PEI-NPs. Taken together, our study showed the importance of assessing bio-functionality and binding stability of functionalized growth factors using proper biological models. It also shows that successful functionalization of magnetic NPs with growth factors is dependent on the used binding chemistry and that it is hardly predictable. For use as therapeutics, functionalization strategies have to be reproducible and future studies are needed. [ABSTRACT FROM AUTHOR]

Nano-oncology, the application of Nanomedicine to cancer diagnosis and treatment, has the potential to transform clinical oncology by enhancing the efficacy of cancer chemotherapy for a wide spectrum of invasive cancers. It achieves this by enabling novel drug delivery systems which target the tumour site with several functional molecules, including tumour-specific ligands, antibodies, cytotoxic agents, and imaging probes simultaneously thereby improving tumour response rates in addition to significant reduction of the systemic toxicity associated with current chemotherapy regimens. For this reason, nano-oncology is attracting considerable scientific interest and a growing investment by the global pharmaceutical industry. Several therapeutic nano-carriers have been approved for clinical use and others are undergoing phase II and III clinical trials. This paper describes the current approved formulations, such as liposomes and polymeric nanoparticles, and discusses the overall present status of nano-oncology as an emerging branch of nanomedicine and its future perspectives in cancer and therapy. [ABSTRACT FROM AUTHOR]

Summary: The use of polymeric carriers containing dispersed magnetic nanocrystalline particles has attracted considerable interest in the medical field. In this paper, we propose an innovative nanotechnological platform for cancer therapy, based on highly magnetized, biodegradable, and biocompatible polymeric nanoparticles. Alginate magnetic nanoparticles were prepared by our group by an efficient emulsion/reticulation technique and tested as drug delivery system. Here, we present a potential application that combines, in a single nanovector, efficient targeting, overcoming of bio-barriers, drug delivery, and physical disruption of tumor tissues. [Copyright &y& Elsevier]