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The systemic delivery of composite nanoparticles remains an outstanding challenge in cancer nanomedicine, and the principal reason is a complex interplay of biological barriers. In this regard, adaptive cell transfer may represent an alternative solution to circumvent these barriers down to the tumor microenvironment. Here, tumor-tropic macrophages are proposed as a tool to draw and vehiculate modular nanoparticles integrating magnetic and plasmonic components. The end result is a bionic shuttle that exhibits a plasmonic band within the so-called therapeutic window arising from as much as 40 pg Au per cell, magnetization in the order of 150 pemu per cell, and more than 90% of the pristine viability and chemotactic activity of its biological component, until at least two days of preparation. Its synergistic combination of plasmonic, magnetic and tumor-tropic functions is assessed in vitro for applications as magnetic guidance or sorting, with a propulsion around 4 μm s -1 for a magnetic gradient of 0.8 T m -1 , the optical hyperthermia of cancer, with stability of photothermal conversion to temperatures exceeding 50 ∘ C, and the photoacoustic imaging of cancer under realistic conditions. These results collectively suggest that a bionic design may be a promising roadmap to reconcile the efforts for multifunctionality and targeted delivery, which are both key goals in nanomedicine., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

We report on the use of organosilica shells to couple gold nanorods to functional peptides and modulate their physiochemical and biological profiles. In particular, we focus on the case of cell penetrating peptides, which are used to load tumor-tropic macrophages and implement an innovative drug delivery system for photothermal and photoacoustic applications. The presence of organosilica exerts subtle effects on multiple parameters of the particles, including their size, shape, electrokinetic potential, photostability, kinetics of endocytic uptake and cytotoxicity, which are investigated by the interplay of colorimetric methods and digital holographic microscopy. As a rule of thumb, as the thickness of organosilica increases from none to ∼30nm, we find an improvement of the photophysical performances at the expense of a deterioration of the biological parameters. Therefore, detailed engineering of the particles for a certain application will require a careful trade-off between photophysical and biological specifications., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Gold nanorods (GNRs) are important platforms for biosensing and drug delivery. As for most nanomaterials, appropriate coatings such as polyethylene glycol (PEG) are needed to stabilize GNRs within biological fluids. We show here that the interactions of GNRs with proteins can be finely modulated through surface modification using PEG-containing chains bearing charged headgroups. Interestingly, introduction of amino or carboxylate groups produces relevant and differential changes in GNR interactions with three representative proteins: lysozyme, cytochrome c, and bovine serum albumin. These effects were explored through the direct monitoring of plasmonic bands of the GNRs and are supported by independent dynamic light scattering (DLS) and circular dichroism (CD) determinations. Notably, GNR-protein interactions observed for these charged GNRs can be almost completely reversed by salt addition. These observations demonstrate the importance of electrostatic effects in governing GNR-protein interactions, and provide a basis for new sensing and delivery platforms., (Copyright © 2015 Elsevier Inc. All rights reserved.)

An electrochemical immunoassay for neopterin was developed using recently produced specific antibodies immobilized to protein A-coated magnetic beads in combination with differential pulse voltammetry and screen-printed array of electrodes. Neopterin-alkaline phosphatase conjugate was used as label in a competitive assay format. Multiplexed analysis of neopterin was demonstrated by replacing the traditional ELISA with electrochemical detection and the traditional plastic wells with screen-printed array of electrodes. The optimized electrochemical method, based on polyclonal antibodies, reached a limit of detection of 0.008 ng/mL with an average RSD %=10. Serum samples collected from patients with sepsis, healthy volunteers and other patients without a confirmed clinical diagnosis were also analyzed. The obtained results, compared with those of a commercial ELISA kit, had a significant correlation, showing the possibility to distinguish among the serum samples from ill or healthy subjects., (Copyright © 2014 Elsevier B.V. All rights reserved.)

A comparison of two electrochemical immunosensing strategies for PCBs detection, based on the use of two different solid phases, is here discussed. In both cases, carbon-based screen-printed electrodes (SPEs) are used as transducers in a direct competitive immunoassay scheme, where PCBs in solution compete with the tracer PCB28-alkaline phosphatase (AP) labeled for antibodies immobilized onto the solid-phase. In the standard format (called EI strategy), SPEs are both the solid-phase for immunoassay and electrochemical transducers: in this case the immunochemical reaction occurs onto the working electrode. Finally, the enzymatic substrate is added and an electroactive product is generated and detected by electrochemical measurement. In order to improve the performances of the system, a new approach (called EMI strategy) is developed by using functionalized magnetic beads as solid phase for the competitive assay; only after the immunosensing step they are captured by a magnet onto the working surface of the SPE for the electrochemical detection. Experimental results evidenced that the configuration based on the use of separate surfaces for immunoassay and for electrochemical detection gave the best results in terms of sensitivity and speed of the analysis. The improvement of analytical performances of the immunosensor based on EMI strategy was also demonstrated by the analysis of some spiked samples.

An electrochemical immunosensor for polychlorinated biphenyl (PCB) detection based on graphite screen-printed low-density arrays and on magnetic beads is reported. The immunological reaction for the detection of PCBs is based on a direct competitive assay using alkaline phosphatase (AP) as enzymatic label. After the immunochemical recognition, the modified magnetic beads are captured by a magnet on the surface of the graphite working electrode. The electrochemical detection is thus achieved through the addition of the AP substrate (alpha-naphthyl-phosphate). Two different antibodies (sIgG anti-PCB28 and rIgG anti-PCB77) were tested and compared in terms of sensitivity and ability to recognise different congeners. The developed electrochemical magneto-immunosensor (EMI) was successfully combined with solid-phase extraction (SPE) for the analysis of PCBs in milk samples. In spiked samples a recovery of 80% was obtained. The proposed strategy offers great promise for rapid, simple, cost-effective, and on-site analysis of clinical, food and environmental samples, considering also that low-density arrays allow the simultaneous analysis of different processed samples.