"Swallowing the doctor": an interview with Joao Conde about the future of nanomedicine

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The Golden Age in Cancer Nanobiotechnology: Quo Vadis?

Since Richard Feynman and his famous talk “There’s plenty of room at the bottom” in an American Physical Society meeting at Caltech in 1959, Nanotechnology has led to the development of novel materials and devices with a wide-range of applications, especially in imaging, diagnostics, and therapy, which contributed to the early detection and treatment of cancer and metastasis (Ferrari, 2005; Conde et al., 2012a; Schroeder et al., 2012).Marie Curie International Fellowship (FP7-PEOPLE-2013-IOF, Project 626386

Implantable hydrogel embedded dark-gold nanoswitch as a theranostic probe to sense and overcome cancer multidrug resistance

Multidrug resistance (MDR) in cancer cells is a substantial limitation to the success of chemotherapy. Here, we describe facile means to overcome resistance by silencing the multidrug resistance protein 1 (MRP1), before chemotherapeutic drug delivery in vivo with a single local application. Our platform contains hydrogel embedded with dark-gold nanoparticles modified with 5-fluorouracil (5-FU)-intercalated nanobeacons that serve as an ON/OFF molecular nanoswitch triggered by the increased MRP1 expression within the tumor tissue microenvironment. This nanoswitch can sense and overcome MDR prior to local drug release. The nanobeacons comprise a 5-FU intercalated DNA hairpin, which is labeled with a near-infrared (NIR) dye and a dark-quencher. The nanobeacons are designed to open and release the intercalated drug only upon hybridization of the DNA hairpin to a complementary target, an event that restores fluorescence emission due to nanobeacons conformational reorganization. Despite the cross-resistance to 5-FU, more than 90% tumor reduction is achieved in vivo in a triple-negative breast cancer model following 80% MRP1 silencing compared with the continuous tumor growth following only drug or nanobeacon administration. Our approach can be applied to reverse cross-resistance to other chemotherapeutic drugs and restore treatment efficacy. As a universal nanotheranostic probe, this platform can pave the way to early cancer detection and treatment.National Cancer Institute (U.S.) (Cancer Center Support (Core) Grant P30-CA14051)Marie Curie International Fellowship (FP7-PEOPLE-2013-IOF, Project 626386

Osteogenic differentiation of human mesenchymal stem cells by the single action of luminescent polyurea oxide biodendrimers

Fundação para a Ciência e a Tecnologia for financial support through project PTDC/MEC-ONC/29327/2017 and the PhD grant SFRH/BD/109006/2015 (R.F.P.). We also thank Dr. Luisa Maia (UCIBIO, FCT-UNL) for EPR measurements.Polyurea oxide (PURO) biodendrimers are a class of dendrimers that can trigger osteogenic differentiation of human mesenchymal stem cells (hMSCs). PURO biodendrimers are prepared by simple, solventless oxidation of polyurea dendrimers using hydrogen peroxide as the oxidant in quantitative yield, retaining both biocompatibility (up to 10 mg/mL for higher generations) and the non-traditional intrinsic luminescence. The effect of PURO biodendrimers in the differentiation of hMSCs was found by the single addition to a standard growth medium for MSCs differentiation (without differentiation inducers). After 21 days of incubation, the formation of osteoblasts was confirmed by the alizarin red staining assay and alkaline phosphatase activity. This is the first report of in vitro osteodifferentiation fully regulated by synthetic soft polymers such as dendrimers. Current osteogenic differentiation protocols rely on an in vitro inducing formulation (including dexamethasone, ascorbic acid, and β-glycerophosphate), which lacks therapeutic potential in vivo. The outstanding role of dendrimers in nanomedicine, under clinic translation, combined with this feature is envisaged to foster PURO dendrimers as an important strategy in cell therapy and regenerative medicine.publishersversionpublishe

Antibody-Drug Gold Nanoantennas with Raman Spectroscopic Fingerprints for in Vivo Tumour Theranostics

Inspired by the ability of SERS nanoantennas to provide an integrated platform to enhance disease targeting in vivo, we developed a highly sensitive probe for in vivo tumoral recognition with the capacity to target specific cancer biomarkers such as epidermal growth factor receptors (EGFR) on human cancer cells and xenograft tumour models. Here, we used ~90 nm gold nanoparticles capped by a Raman reporter, encapsulated and entrapped by larger polymers and a FDA antibody-drug conjugate –Cetuximab (Erbitux®) – that specifically targets EGFR and turns off a main signalling cascade for cancer cells to proliferate and survive. These drug/SERS gold nanoantennas present a high Raman signal both in cancer cells and in mice bearing xenograft tumours. Moreover, the Raman detection signal is accomplished simultaneously by extensive tumour growth inhibition in mice, making these gold nanoantennas ideal for cancer nanotheranostics, i.e. tumour detection and tumoral cell inhibition at the same time

Derivation of the near-surface dielectric function of amorphous silicon from photoelectron loss spectra

International audienceThe near-surface dielectric function ε(ℏω) of hydrogenated amorphous silicon (a-Si:H) films has been derived from X-ray photoelectron energy-loss spectra, over the energy range 0-45 eV. Removal of low lying single-electron excitations is a prerequisite step to proceed to the derivation of the single plasmon energy loss function Im[−1/ε(ℏω)] due to collective electron oscillations. Several methods are compared to separate interband transitions from bulk or surface plasmons excitation. The shape of interband excitation loss in the range 1-10 eV can be described by a Henke function; alternatively, its removal using a sigmoid weighting function is a low-noise and reliable method. After deconvolution of multiple plasmon losses and self-consistent elimination of surface plasmon excitation, the single plasmon loss distribution allows recovery of optical (ellipsometry) data measured in the near-UV to visible range

Austenite reversion kinetics and stability during tempering of an additively manufactured maraging 300 steel

Reverted austenite is a metastable phase that can be used in maraging steels to increase ductility via transformation-induced plasticity or TRIP effect. In the present study, 18Ni maraging steel samples were built by selective laser melting, homogenized at 820¿°C and then subjected to different isothermal tempering cycles aiming for martensite-to-austenite reversion. Thermodynamic simulations were used to estimate the inter-critical austenite¿+¿ferrite field and to interpret the results obtained after tempering. In-situ synchrotron X-ray diffraction was performed during the heating, soaking and cooling of the samples to characterize the martensite-to-austenite reversion kinetics and the reverted austenite stability upon cooling to room temperature. The reverted austenite size and distribution were measured by Electron Backscattered Diffraction. Results showed that the selected soaking temperatures of 610¿°C and 650¿°C promoted significant and gradual martensite-to-austenite reversion with high thermal stability. Tempering at 690¿°C caused massive and complete austenitization, resulting in low austenite stability upon cooling due to compositional homogenization.Peer ReviewedPostprint (author's final draft

Miniaturization of aqueous two-phase extraction for biological applications

Aqueous two-phase extraction (ATPE) is a biocompatible liquid-liquid (L-L) separation technique that has been under research for several decades towards the purification of biomolecules, ranging from small metabolites to large animal cells. More recently, with the emergence of rapid-prototyping techniques for fabrication of microfluidic structures with intricate designs, ATPE gained an expanded range of applications utilizing physical phenomena occurring exclusively at the microscale. Studies of ATPSs at nanoliter-scale are further extending the range of applications of these systems by taking advantage of rapid diffusion times, increased degree of control of individual liquid streams and droplets, continuous flow and the integration of multi-dimensional separation modes. Several examples of microfluidic ATPS platforms are described. The partition of molecules between two co-flowing liquid streams confined within a microchannel was successfully demonstrated by the on-line extraction of a fluorescein isothiocyanate (FITC) labeled immunoglobulin G (IgG) from a salt rich flow to a PEG rich flow. IgG diffusion to the PEG-rich phase was complete after 16 cm of channel using flow rates of 1 and 0.2 μL/min for the salt and PEGrich phases respectively. Besides proteins, ATPS have also been used to separate other more complex biomolecules in microfluidics such as virus-like particles. The potential of miniaturization as a high-throughput screening tool has also been explored. The developed setup allowed the screening of a wide range of concentrations inside the microchannel by varying the flow rates of the solutions while using sub-mL volumes for each ATPS-forming system. As a novel demonstration of the integrative potential of ATPE as a microfluidic sample preparation module, a microfluidic device comprising two modules was developed and used to perform a complex matrix clean-up in-line with an immunoassay. References: Silva, D. F., Azevedo, A. M., Fernandes, P., Chu, V. et al., Design of a microfluidic platform for monoclonal antibody extraction using an aqueous two-phase system. J. Chromatogr. A 2012, 1249, 1–7. Jacinto, M. J., Soares, R. R. G., Azevedo, A. M., Chu, V. et al., Optimization and miniaturization of aqueous two phase systems for the purification of recombinant human immunodeficiency virus-like particles from a CHO cell supernatant. Sep. Purif. Technol. 2015, 154, 27–35. Silva, D. F. C., Azevedo, A. M., Fernandes, P., Chu, V. et al., Determination of aqueous two phase system binodal curves using a microfluidic device. J. Chromatogr. A 2014, 1370, 115–120. Soares, R. R., Novo, P., Azevedo, A. M., Fernandes, P. et al., On-chip sample preparation and analyte quantification using a microfluidic aqueous two-phase extraction coupled with an immunoassay. Lab Chip 2014, 14, 4284–429

RNAi-based Glyconanoparticles Trigger Apoptotic Pathways for In Vitro and In Vivo Enhanced Cancer-Cell Killing

biotechnology and material science due to their amazing physical, chemical and biological properties. Here, siRNA GlycoNPs (AuNP@PEG@Glucose@siRNA) in comparison to PEGylated GlycoNPs (AuNP@PEG@Glucose) were applied in vitro to a luciferase-CMT/167 adenocarcinoma cancer cell line and in vivo via intratracheal instillation directly into the lung of B6 albino mice grafted with luciferase-CMT/167 adenocarcinoma cells. siRNA GlycoNPs but not PEGylated GlycoNPs induced the expression of pro-apoptotic proteins such as Fas/CD95 and caspases 3 and 9 in CMT/167 adenocarcinoma cells in a dose dependent manner, independent from the inflammatory response, evaluated by bronchoalveolar lavage cell counting. Moreover, in vivo pulmonary delivered siRNA GlycoNPs were capable of targeting c-Myc gene expression (a crucial regulator of cell proliferation and apoptosis) via in vivo RNAi in tumour tissue, leading to a ~80% reduction in tumour size without inflammation associated

Chiral Antioxidant-based Gold Nanoclusters Reprogram DNA Epigenetic Patterns

Epigenetic modifications sit ‘on top of’ the genome and influence DNA transcription, which can force a significant impact on cellular behavior and phenotype and, consequently human development and disease. Conventional methods for evaluating epigenetic modifications have inherent limitations and, hence, new methods based on nanoscale devices are needed. Here, we found that antioxidant (glutathione) chiral gold nanoclusters induce a decrease of 5-hydroxymethylcytosine (5hmC), which is an important epigenetic marker that associates with gene transcription regulation. This epigenetic change was triggered partially through ROS activation and oxidation generated by the treatment with glutathione chiral gold nanoclusters, which may inhibit the activity of TET proteins catalyzing the conversion of 5-methylcytosine (5mC) to 5hmC. In addition, these chiral gold nanoclusters can downregulate TET1 and TET2 mRNA expression. Alteration of TET-5hmC signaling will then affect several downstream targets and be involved in many aspects of cell behavior. We demonstrate for the first time that antioxidant-based chiral gold nanomaterials have a direct effect on epigenetic process of TET-5hmC pathways and reveal critical DNA demethylation patterns