Search

Fluorescence microscopy has become an essential tool for biologists, to visualize the dynamics of intracellular structures with specific labeling. Quantitatively measuring the dynamics of moving objects inside the cell is pivotal for understanding of the underlying regulatory mechanism. Protein-containing vesicles are involved in various biological processes such as material transportation, organelle interaction, and hormonal regulation, whose dynamic characteristics are significant to disease diagnosis and drug screening. Although some algorithms have been developed for vesicle tracking, most of them have limited performance when dealing with images with low resolution, poor signal-to-noise ratio (SNR) and complicated motion. Here, we proposed a novel deep learning-based method for intracellular vesicle tracking. We trained the U-Net for vesicle localization and motion classification, with demonstrates great performance in both simulated datasets and real biological samples. By combination with fan-shaped tracker (FsT) we have previously developed, this hybrid new algorithm significantly improved the performance of particle tracking with the function of subsequently automated vesicle motion classification. Furthermore, its performance was further demonstrated in analyzing with vesicle dynamics in different temperature, which achieved reasonable outcomes. Thus, we anticipate that this novel method would have vast applications in analyzing the vesicle dynamics in living cells. [ABSTRACT FROM AUTHOR]

Abstract: One-step approach was developed to synthesize amino-reserved chitosan-graft-polycaprolactone (CS-g-PCL) by grafting ε-CL oligomers onto the hydroxyl groups of CS via ring-opening polymerization by using methanesulfonic acid as solvent and catalyst. The controllable grafting content of PCL within CS-g-PCL provided the possibility to manipulate the biodegradation rate, hydrophilicity, and hence the cytotoxicity of CS-g-PCL. As a result, the specimen synthesized from the feed molar ratio of glucosamine units in CS vs. ε-CL as 1:12 showed equivalent cytotoxicity to the neat CS and PCL against KB cell line, and the cell viability was almost close to 100%. In addition, CS-g-PCL exhibited good solubility in organic solvents, facilitating formation of PCL/CS-g-PCL blend nanofibers via electrospinning with the use of DMF/CHCl3 as solvent. Owing to the enhanced cellular attachment results from cationic amino groups, it is promising that these copolymers are ideal substances for developing drug carriers and tissue engineering scaffolds. [Copyright &y& Elsevier]