Advances in electrical and magnetic stimulation on nerve regeneration.

Central and peripheral nerve injuries pose a great threat to people. Complications such as inflammation, muscle atrophy, traumatic neuromas and delayed reinnervation can bring huge challenges to clinical practices and barriers to complete nerve regrowth. Physical interventions such as electrical and magnetic stimulation show satisfactory results with varying parameters for acute and chronic nerve damages. The biological basis of electrical and magnetic stimulation mainly relies on protein synthesis, ion channel regulation and growth factor secretion. This review focuses on the various paradigms used in different models of electrical and magnetic stimulation and their regenerative potentials and underlying mechanisms in nerve injuries. The combination of physical stimulation and conductive biomaterial scaffolds displays an infinite potentiality in translational application in nerve regeneration.

Genome-centric metagenomics resolves microbial diversity and prevalent truncated denitrification pathways in a denitrifying PAO-enriched bioprocess.

Denitrification is the stepwise microbial reduction of nitrate or nitrite (NO2-) to nitrogen gas via the obligate intermediates nitric oxide (NO) and nitrous oxide (N2O). Substantial N2O accumulation has been reported in denitrifying enhanced biological phosphorus removal (EBPR) bioreactors enriched in denitrifying polyphosphate accumulating organisms (DPAOs), but little is known about underlying mechanisms for N2O generation, prevalence of complete versus truncated denitrification pathways, or the impact of NO2- feed on DPAO-enriched consortia. To address this knowledge gap, we employed genome-resolved metagenomics to investigate nitrogen transformation potential in a NO2- fed denitrifying EBPR bioreactor enriched in Candidatus Accumulibacter and prone to N2O accumulation. Our analysis yielded 41 near-complete metagenome-assembled genomes (MAGs), including two co-occurring Accumulibacter strains affiliated with clades IA and IC (the first published genome from this clade) and 39 non-PAO flanking bacterial genomes. The dominant Accumulibacter clade IA encoded genes for complete denitrification, while the lower abundance Accumulibacter clade IC harbored all denitrification genes except for a canonical respiratory NO reductase. Analysis of the 39 non-PAO MAGs revealed a high prevalence of taxa harboring an incomplete denitrification pathway. Of the 27 MAGs harboring capacity for at least one step in the denitrification pathway, 10 were putative N2O producers lacking N2O reductase, 16 were putative N2O reducers that lacked at least one upstream denitrification gene, and only one harbored a complete denitrification pathway. We also documented increasing abundance over the course of reactor operation of putative N2O producers. Our results suggest that the unusually high levels of N2O production observed in this Accumulibacter-enriched consortium are linked in part to the selection for non-PAO flanking microorganisms with truncated denitrification pathways.

Single-molecule detection of biomarker and localized cellular photothermal therapy using an optical microfiber with nanointerface.

For early-stage diagnostics, there is a strong demand for sensors that can rapidly detect biomarkers at ultralow concentration or even at the single-molecule level. Compared with other types of sensors, optical microfibers are more convenient for use as point-of-care devices in early-stage diagnostics. However, the relatively low sensitivity strongly hinders their use. To this end, an optical microfiber is functionalized with a plasmonic nanointerface consisting of black phosphorus-supported Au nanohybrids. The microfiber is able to detect epidermal growth factor receptor (ErbB2) at concentrations ranging from 10 zM to 100 nM, with a detection limit of 6.72 zM, enabling detection at the single-molecule level. The nanointerface-sensitized microfiber is capable of differentiating cancer cells from normal cells and treating cancer cells through cellular photothermal therapy. This work opens up a possible approach for the integration of cellular diagnosis and treatment.

Iron Oxide Nanoparticles-Based Vaccine Delivery for Cancer Treatment.

Modern therapeutic cancer vaccines need simple and effective formulations to enhance both humoral and cellular immune responses. Nanoparticles have obtained more and more attention in the development of vaccine delivery platforms. Moreover, nanoparticles-based vaccine delivery platform has high potential for improving the immunogenicity of vaccine. The Food and Drug Administration (FDA) has approved many types of iron oxide nanoparticles for clinical use, such as treating iron deficiency, contrast agents for magnetic resonance imaging (MRI) and drug delivery platforms. In this study, we explored a novel combined use of iron oxide nanoparticles (superparamagnetic Fe3O4 nanoparticles) as a vaccine delivery platform and immune potentiator, and investigated how this formulation affected cytokine expression in macrophages and dendritic cells (DCs) in vitro and tumor growth in vivo. Comparing with soluble OVA alone and iron oxide nanoparticles alone, we found significant differences in immune responses and tumor inhibition induced by OVA formulated with iron oxide nanoparticles. Our iron oxide nanoparticles greatly promoted the activation of immune cells and cytokine production, inducing potent humoral and cellular immune responses. These results suggest that this nanoparticle-based delivery system has strong potential to be utilized as a general platform for cancer vaccines.