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Antibiotic resistance is a major global health concern that requires action across all sectors of society. In particular, to allow conservative and effective use of antibiotics clinical settings require better diagnostic tools that provide rapid determination of antimicrobial susceptibility. We present a method for rapid and scalable antimicrobial susceptibility testing using stationary nanoliter droplet arrays that is capable of delivering results in approximately half the time of conventional methods, allowing its results to be used the same working day. In addition, we present an algorithm for automated data analysis and a multiplexing system promoting practicality and translatability for clinical settings. We test the efficacy of our approach on numerous clinical isolates and demonstrate a 2-d reduction in diagnostic time when testing bacteria isolated directly from urine samples.antibiotic resistance | nanoliter wells | antibiotic susceptibility testing | microfluidics | resazurin

Increasing public awareness of foodborne illnesses, factory farming, and the ecological footprint of the meat industry, has generated the need for animal-free meat alternatives. In the last decade, scientists have begun to leverage the knowledge and tools accumulated in the fields of stem cells and tissue engineering toward the development of cell-based meat (i.e., clean meat). In tissue engineering, the physical and biochemical features of the native tissue can be mimicked; cells and biomaterials are integrated under suitable culture conditions to form mature tissues. More specifically, in skeletal muscle tissue engineering, a plurality of cell types can be co-cultured on a 3D scaffold to generate muscle fibers, blood vessels and a dense extracellular matrix (ECM). This review focuses on tissue engineering of skeletal muscle and the adjustments needed for clean meat development. We discuss the skeletal muscle structure and composition, and elaborate on cell types from farm animals that have the potential to recapitulate the muscle ECM, blood vessels, muscle fibers and fat deposits. We also review relevant biomaterials, primarily for fabricating scaffolds that can mimic the intramuscular connective tissues, as well as gene expression studies on the biological pathways that influence meat quality.

Cultivating meat from stem cells rather than by raising animals is a promising solution to concerns about the negative externalities of meat production. For cultivated meat to fully mimic conventional meat's organoleptic and nutritional properties, innovations in scaffolding technology are required. Many scaffolding technologies are already developed for use in biomedical tissue engineering. However, cultivated meat production comes with a unique set of constraints related to the scale and cost of production as well as the necessary attributes of the final product, such as texture and food safety. This review discusses the properties of vertebrate skeletal muscle that will need to be replicated in a successful product and the current state of scaffolding innovation within the cultivated meat industry, highlighting promising scaffold materials and techniques that can be applied to cultivated meat development. Recommendations are provided for future research into scaffolds capable of supporting the growth of high-quality meat while minimizing production costs. Although the development of appropriate scaffolds for cultivated meat is challenging, it is also tractable and provides novel opportunities to customize meat properties.

Microfluidic water-in-oil droplets that serve as separate, chemically isolated compartments can be applied for single-cell analysis; however, to investigate encapsulated cells effectively over prolonged time periods, an array of droplets must remain stationary on a versatile substrate for optimal cell compatibility. We present here a platform of unique geometry and substrate versatility that generates a stationary nanodroplet array by using wells branching off a main microfluidic channel. These droplets are confined by multiple sides of a nanowell and are in direct contact with a biocompatible substrate of choice. The device is operated by a unique and reversed loading procedure that eliminates the need for fine pressure control or external tubing. Fluorocarbon oil isolates the droplets and provides soluble oxygen for the cells. By using this approach, the metabolic activity of single adherent cells was monitored continuously over time, and the concentration of viable pathogens in blood-derived samples was determined directly by measuring the number of colony-formed droplets. The method is simple to operate, requires a few microliters of reagent volume, is portable, is reusable, and allows for cell retrieval. This technology may be particularly useful for multiplexed assays for which prolonged and simultaneous visual inspection of many isolated single adherent or nonadherent cells is required.single cell | nanoliter array | diagnostics C ommon single-cell analysis methods, such as flow cytometry and mass cytometry (1), offer high throughput and accurate single-cell marker quantification, yet they lack the ability to monitor large numbers of single cells continuously and simultaneously in performance-based assays (2, 3). Conventional microscopy may be used for these assays; however, in the case of single cells, they cannot analyze extracellular events, such as secretion. To achieve this, cells must be isolated in compartments that can sustain cell viability and growth while permitting conventional optical analysis over many hours to days. Dropletbased microfluidics, which enables single-cell encapsulation in nano-and subnanoliter droplets by surrounding microscopic aqueous medium with an immiscible carrier fluid (4-8), recently gained interest with the appearance of digital PCR (9-11). Much of the work thus far has been directed toward improving droplet manipulation capabilities (12-16). With these methods, droplets are mobile, and thus cytometry is performed under flow conditions (17), making continuous monitoring of single cells difficult. Continuous monitoring may be achieved by using stationary indexed droplets, but many current droplet immobilization techniques are limited by pressure coupling between droplet generation and capture events, as well as the requirement to adjust droplet volume to nanowell size (6,18,19). The vast majority of methods used to generate water-in-oil droplets begin by priming a continuous oil phase in a microfluidic channel followed by an injection of a dispersed (aqueous) medium (2...