Lithographically defined encoded magnetic heterostructures for the targeted screening of kidney cancer.

Renal cell carcinoma (RCC) is the 7th commonest cancer in the UK and the most lethal urological malignancy; 50% of all RCC patients will die from the condition. However, if identified early enough, small RCCs are usually cured by surgery or percutaneous procedures, with 95% 10 year survival. This study describes a newly developed non-invasive urine-based assay for the early detection of RCC. Our approach uses encoded magnetically controllable heterostructures as a substrate for immunoassays. These heterostructures have molecular recognition abilities and embedded patterned codes for a rapid identification of RCC biomarkers. The magnetic heterostructures developed for this study have a magnetic configuration designed for a remote multi axial control of their orientation by external magnetic fields, this control facilitates the code readout when the heterostructures are in liquid. Furthermore, the optical encoding of each set of heterostructures provides a multiplexed analyte capture platform, as different sets of heterostructures, specific to different biomarkers can be mixed together in a patient sample. Our results show a precise magnetic control of the heterostructures with an efficient code readout during liquid immunoassays. The use of functionalised magnetic heterostructures as a substrate for immunoassay is validated for urine specimen spiked with recombinant RCC biomarkers. Initial results of the newly proposed screening method on urine samples from RCC patients, and controls with no renal disorders are presented in this study. Comprehensive optimisation cycles are in progress to validate the robustness of this technology as a novel, non-invasive screening method for RCC.

Early detection of kidney cancer using urinary proteins: a truly non-invasive strategy.

OBJECTIVES: To review urinary protein biomarkers as potential non-invasive, easily obtainable, early diagnostic tools in renal cell carcinoma (RCC). METHODS: A PubMed database search was performed up to the year 2020 to identify primary studies reporting potential urinary protein biomarkers for RCC. Separate searches were conducted to identify studies describing appropriate methods of developing cancer screening programmes and detection of cancer biomarkers. RESULTS: Several urinary protein biomarkers are under validation for RCC diagnostics, e.g. aquaporin-1, perilipin-2, carbonic anhydrase-9, Raf-kinase inhibitory protein, nuclear matrix protein-22, 14-3-3 Protein ß/α and neutrophil gelatinase-associated lipocalin. However, none has yet been validated or approved for clinical use due to low sensitivity or specificity, inconsistencies in appropriate study design, or lack of external validation. CONCLUSIONS: Evaluation of biomarkers' feasibility, sample preparation and storage, biomarker validation, and the application of novel technologies may provide a solution that maximises the potential for a truly non-invasive biomarker in early RCC diagnostics.

Combination of In Situ Lcn2 pRNA-RNAi Nanotherapeutics and iNSC Transplantation Ameliorates Experimental SCI in Mice.

Spinal cord injury (SCI) is a debilitating neurological condition characterized by different cellular and molecular mechanisms that interplay in exacerbating the progression of the pathology. No fully restorative therapies are yet available, and it is thus becoming recognized that combinatorial approaches aimed at addressing different aspects of SCI will likely results in greater functional outcomes. Here we employed packaging RNA-mediated RNA interference (pRNA-RNAi) nanotherapeutics to downregulate in situ the expression of lipocalin 2 (Lcn2), a known mediator of neuroinflammation and autocrine mediator of reactive astrogliosis, and to create a more amenable niche for the subsequent transplantation of induced neural stem cells (iNSCs). To our knowledge, this is the first approach that takes advantage of the modular and multifunctional pRNA three-way junction platform in the SCI niche, while also exploiting the therapeutic potential of immune-compatible and feasible iNSC transplants. We show the combination of such treatments in a mouse model of contusion thoracic SCI leads to significant improvement of locomotor function, albeit not better than single pRNA-RNAi treatment, and results in synergistic histopathological effects, such as reduction of glial scar volume, diminished pro-inflammatory response, and promotion of neuronal survival. Our results provide evidence for a novel combinatorial approach for treating SCI.

In vitro evaluation of experimental light activated gels for tooth bleaching.

Dental bleaching is an important part of aesthetic dentistry. Various strategies have been created to enhance the bleaching efficacy. As one such strategy, light-activated nanoparticles that enable localized generation of reactive oxygen species have been developed. Here, we evaluated the cellular response to experimental gels containing these materials in in vitro models. L-929 cells, 3T3 cells, and gingival fibroblasts were exposed to the gels at 50%, 10%, 2%, 0.4%, 0.08%, 0.016%, and 0.0032%. The gels contained TiO2/Ag nanoparticles, TiO2 nanoparticles, hydrogen peroxide (6% hydrogen peroxide), or no added component and were tested with and without exposure to light. Cells were exposed to gels for 24 h or for 30 min. The latter case mimics the clinical situation of a short bleaching gel exposure. Metabolic activity and cell viability were evaluated with MTT and neutral red assays, respectively. We found a dose-dependent reduction of formazan formation and neutral red staining with gels containing TiO2/Ag nanoparticles or TiO2 nanoparticles in the 24 h setting with and without illumination. The strongest reduction, which was not dose-dependent in the evaluated concentrations, was found for the gel containing hydrogen peroxide. Gels with TiO2 nanoparticles showed a similar response to gel without particles. TiO2/Ag gel showed a slightly higher impact. When the gels were removed by rinsing after 30 min of exposure without light illumination, gel containing TiO2/Ag nanoparticles showed a stronger reduction of formazan formation and neutral red staining than gel containing TiO2 particles. Exposure of cells for 30 min under illumination and consequent rinsing off the gels also showed that Ag-containing particles can have a higher impact on the metabolic activity and viability than particles from TiO2. Overall our results show that experimental bleaching gels containing TiO2/Ag or TiO2 nanoparticles are less cytotoxic than hydrogen peroxide-containing gel. When gels are removed, gel containing TiO2/Ag particles exhibit a stronger reduction of metabolic activity and viability than the gel containing TiO2.

RNA Nanotherapeutics for the Amelioration of Astroglial Reactivity.

In response to injuries to the CNS, astrocytes enter a reactive state known as astrogliosis, which is believed to be deleterious in some contexts. Activated astrocytes overexpress intermediate filaments including glial fibrillary acidic protein (GFAP) and vimentin (Vim), resulting in entangled cells that inhibit neurite growth and functional recovery. Reactive astrocytes also secrete inflammatory molecules such as Lipocalin 2 (Lcn2), which perpetuate reactivity and adversely affect other cells of the CNS. Herein, we report proof-of-concept use of the packaging RNA (pRNA)-derived three-way junction (3WJ) motif as a platform for the delivery of siRNAs to downregulate such reactivity-associated genes. In vitro, siRNA-3WJs induced a significant knockdown of Gfap, Vim, and Lcn2 in a model of astroglial activation, with a concomitant reduction in protein expression. Knockdown of Lcn2 also led to reduced protein secretion from reactive astroglial cells, significantly impeding the perpetuation of inflammation in otherwise quiescent astrocytes. Intralesional injection of anti-Lcn2-3WJs in mice with contusion spinal cord injury led to knockdown of Lcn2 at mRNA and protein levels in vivo. Our results provide evidence for siRNA-3WJs as a promising platform for ameliorating astroglial reactivity, with significant potential for further functionalization and adaptation for therapeutic applications in the CNS.

Insight in the chemistry of laser-activated dental bleaching.

The use of optical radiation for the activation of bleaching products has not yet been completely elucidated. Laser light is suggested to enhance the oxidizing effect of hydrogen peroxide. Different methods of enhancing hydrogen peroxide based bleaching are possible. They can be classified into six groups: alkaline pH environment, thermal enhancement and photothermal effect, photooxidation effect and direct photobleaching, photolysis effect and photodissociation, Fenton reaction and photocatalysis, and photodynamic effect.

Laser teeth bleaching: evaluation of eventual side effects on enamel and the pulp and the efficiency in vitro and in vivo.

Light and heat increase the reactivity of hydrogen peroxide. There is no evidence that light activation (power bleaching with high-intensity light) results in a more effective bleaching with a longer lasting effect with high concentrated hydrogen peroxide bleaching gels. Laser light differs from conventional light as it requires a laser-target interaction. The interaction takes place in the first instance in the bleaching gel. The second interaction has to be induced in the tooth, more specifically in the dentine. There is evidence that interaction exists with the bleaching gel: photothermal, photocatalytical, and photochemical interactions are described. The reactivity of the gel is increased by adding photocatalyst of photosensitizers. Direct and effective photobleaching, that is, a direct interaction with the colour molecules in the dentine, however, is only possible with the argon (488 and 415 nm) and KTP laser (532 nm). A number of risks have been described such as heat generation. Nd:YAG and especially high power diode lasers present a risk with intrapulpal temperature elevation up to 22°C. Hypersensitivity is regularly encountered, being it of temporary occurrence except for a number of diode wavelengths and the Nd:YAG. The tooth surface remains intact after laser bleaching. At present, KTP laser is the most efficient dental bleaching wavelength.