Nanozyme-catalysed CRISPR assay for preamplification-free detection of non-coding RNAs.

CRISPR-based diagnostics enable specific sensing of DNA and RNA biomarkers associated with human diseases. This is achieved through the binding of guide RNAs to a complementary sequence that activates Cas enzymes to cleave reporter molecules. Currently, most CRISPR-based diagnostics rely on target preamplification to reach sufficient sensitivity for clinical applications. This limits quantification capability and adds complexity to the reaction chemistry. Here we show the combination of a CRISPR-Cas-based reaction with a nanozyme-linked immunosorbent assay, which allows for the quantitative and colorimetric readout of Cas13-mediated RNA detection through catalytic metallic nanoparticles at room temperature (CrisprZyme). We demonstrate that CrisprZyme is easily adaptable to a lateral-flow-based readout and different Cas enzymes and enables the sensing of non-coding RNAs including microRNAs, long non-coding RNAs and circular RNAs. We utilize this platform to identify patients with acute myocardial infarction and to monitor cellular differentiation in vitro and in tissue biopsies from prostate cancer patients. We anticipate that CrisprZyme will serve as a universally applicable signal catalyst for CRISPR-based diagnostics, which will expand the spectrum of targets for preamplification-free, quantitative detection.

A CRISPR-based assay for the detection of opportunistic infections post-transplantation and for the monitoring of transplant rejection.

In organ transplantation, infection and rejection are major causes of graft loss. They are linked by the net state of immunosuppression. To diagnose and treat these conditions earlier, and to improve long-term patient outcomes, refined strategies for the monitoring of patients after graft transplantation are needed. Here, we show that a fast and inexpensive assay based on CRISPR-Cas13 accurately detects BK polyomavirus DNA and cytomegalovirus DNA from patient-derived blood and urine samples, as well as CXCL9 messenger RNA (a marker of graft rejection) at elevated levels in urine samples from patients experiencing acute kidney transplant rejection. The assay, which we adapted for lateral-flow readout, enables-via simple visualization-the post-transplantation monitoring of common opportunistic viral infections and of graft rejection, and should facilitate point-of-care post-transplantation monitoring.

A bioresorbable biomaterial carrier and passive stabilization device to improve heart function post-myocardial infarction.

The limited regenerative capacity of the heart after a myocardial infarct results in remodeling processes that can progress to congestive heart failure (CHF). Several strategies including mechanical stabilization of the weakened myocardium and regenerative approaches (specifically stem cell technologies) have evolved which aim to prevent CHF. However, their final performance remains limited motivating the need for an advanced strategy with enhanced efficacy and reduced deleterious effects. An epicardial carrier device enabling a targeted application of a biomaterial-based therapy to the infarcted ventricle wall could potentially overcome the therapy and application related issues. Such a device could play a synergistic role in heart regeneration, including the provision of mechanical support to the remodeling heart wall, as well as providing a suitable environment for in situ stem cell delivery potentially promoting heart regeneration. In this study, we have developed a novel, single-stage concept to support the weakened myocardial region post-MI by applying an elastic, biodegradable patch (SPREADS) via a minimal-invasive, closed chest intervention to the epicardial heart surface. We show a significant increase in %LVEF 14 days post-treatment when GS (clinical gold standard treatment) was compared to GS + SPREADS + Gel with and without cells (p ≤ 0.001). Furthermore, we did not find a significant difference in infarct quality or blood vessel density between any of the groups which suggests that neither infarct quality nor vascularization is the mechanism of action of SPREADS. The SPREADS device could potentially be used to deliver a range of new or previously developed biomaterial hydrogels, a remarkable potential to overcome the translational hurdles associated with hydrogel delivery to the heart.