BioTechniques最新文献

In articular cartilage, zone-specific cellular morphology is a typical characteristic of cartilage tissue, which is related with chondrocyte function, inflammation and osteoarthritis (OA). Chondrocyte hypertrophic phenotype is a criticle physiological process which indicates a hallmark of chondrocyte terminal differentiation and bone formation. Thus, developing a in vitro cell culture system for dynamic regulation of single chondrocyte volume at a three-dimensional (3D) level is particularly necessary for understanding how physical cues of matrix microenvironment regulate chondrocyte fate and the degeneration of articular cartilage. Here, based on the soft lithography techniques, we have constructed well-defined single-cell 3D dynamic volume control system to recapitulate the physiological matrix microenvironment of single chondrocyte niche. The results of finite element analysis indicated that the stress and strain distribution in the cell culture region is homogeneous during the stretching process. Additionally, 3D dynamic volume expansion and compression of single cells in physiological or hyperphysiological can be realized in this cell culture system. Our device for single-cell 3D dynamic culture provides a microphysiological culture system for chondrocytes to explore the mechanisms of cartilage hypertrophy, as well as develops a new paradigm for functional cartilage tissue engineering and regenerative medicine.

Introduction: Traumatic brain injury (TBI) is one of the leading causes of death globally and one of the most important diseases indicated by the World Health Organization (WHO). Several studies have concluded that brain damage can dramatically increase functional connectivity (FC) in the brain. The effects of this hyper-connectivity are not yet fully understood and are being studied by neuroscientists. Accordingly, this study identifies areas of the brain where, after brain injury, an acute increase in FC in such areas is observed.

Methods: The data used in this study were downloaded from the accessible open functional magnetic resonance imaging (fMRI) site. The data included fMRI of 14 patients with severe TBI and 12 healthy individuals. The longitudinal model of variance components investigated the difference between FC in the baseline effect and the longitudinal trend between the TBI and control groups.

Results: After fitting the longitudinal model of variance components, no difference was observed between the FC of the two groups due to the baseline effect. However, in the longitudinal trend of FC, there was a statistically significant difference between the three pairs of cerebellum left, cerebellum right, superior frontal gyrus left, superior frontal gyrus right, thalamus left, and thalamus right in the TBI group compared to the control group.

Conclusion: The results showed that FC was sharply increased in 3 pairs of areas in people with TBI. This hyper-connectivity can affect individuals' cognitive functions, including motor and sensory functions. The exact extent of this effect is unclear and requires further investigation by neuroscientists.

In this study, the authors compared the efficiency of automated robotic and manual injection methods for the CRISPR-RfxCas13d (CasRx) system for mRNA knockdown and Cas9-mediated DNA targeting in zebrafish embryos. They targeted the no tail (TBXTA) gene as a proof-of-principle, evaluating the induced embryonic phenotypes. Both Cas9 and CasRx systems caused loss of function phenotypes for TBXTA. Cas9 protein exhibited a higher percentage of severe phenotypes compared with mRNA, while CasRx protein and mRNA showed similar efficiency. Both robotic and manual injections demonstrated comparable phenotype percentages and mortality rates. The findings highlight the potential of RNA-targeting CRISPR effectors for precise gene knockdown and endorse automated microinjection at a speed of 1.0 s per embryo as a high-throughput alternative to manual methods.