Single-cell RNA-sequence analysis of human bone marrow reveals new targets for isolation of skeletal stem cells using spherical nucleic acids.

There is a wealth of data indicating human bone marrow contains skeletal stem cells (SSC) with the capacity for osteogenic, chondrogenic and adipogenic differentiation. However, current methods to isolate SSCs are restricted by the lack of a defined marker, limiting understanding of SSC fate, immunophenotype, function and clinical application. The current study applied single-cell RNA-sequencing to profile human adult bone marrow populations from 11 donors and identified novel targets for SSC enrichment. Spherical nucleic acids were used to detect these mRNA targets in SSCs. This methodology was able to rapidly isolate potential SSCs found at a frequency of <1 in 1,000,000 in human bone marrow, with the capacity for tri-lineage differentiation in vitro and ectopic bone formation in vivo. The current studies detail the development of a platform to advance SSC enrichment from human bone marrow, offering an invaluable resource for further SSC characterisation, with significant therapeutic impact therein.

A SARS-Cov-2 sensor based on upconversion nanoparticles and graphene oxide.

Since the beginning of the COVID-19 pandemic, there has been an increased need for the development of novel diagnostic solutions that can accurately and rapidly detect SARS-CoV-2 infection. In this work, we demonstrate the targeting of viral oligonucleotide markers within minutes without the requirement of a polymerase chain reaction (PCR) amplification step via the use of oligonucleotide-coated upconversion nanoparticles (UCNPs) and graphene oxide (GO).

Enrichment of Skeletal Stem Cells from Human Bone Marrow Using Spherical Nucleic Acids.

Human bone marrow (BM)-derived stromal cells contain a population of skeletal stem cells (SSCs), with the capacity to differentiate along the osteogenic, adipogenic, and chondrogenic lineages, enabling their application to clinical therapies. However, current methods to isolate and enrich SSCs from human tissues remain, at best, challenging in the absence of a specific SSC marker. Unfortunately, none of the current proposed markers alone can isolate a homogeneous cell population with the ability to form bone, cartilage, and adipose tissue in humans. Here, we have designed DNA-gold nanoparticles able to identify and sort SSCs displaying specific mRNA signatures. The current approach demonstrates the significant enrichment attained in the isolation of SSCs, with potential therein to enhance our understanding of bone cell biology and translational applications.

Unveiling the Structure of MoS x Nanocrystals Produced upon Laser Fragmentation of MoS2 Platelets.

Transition-metal dichalcogenide MoS2 nanostructures have attracted tremendous attention due to their unique properties, which render them efficient nanoscale functional components for multiple applications ranging from sensors and biomedical probes to energy conversion and storage devices. However, despite the wide application range, the possibility to tune their size, shape, and composition is still a challenge. At the same time, the correlation of the structure with the optoelectronic properties is still unresolved. Here, we propose a new method to synthesize various morphologies of molybdenum sulfide nanocrystals, on the basis of ultrashort-pulsed laser fragmentation of MoS2 platelets. Depending on the irradiation conditions, multiple MoS x morphologies in the form of nanoribbons, nanospheres, and photoluminescent quantum dots are obtained. Besides the detailed structural analysis of the various crystals formed, the structure-property relation is investigated and discussed.