A Multicenter Large-Sample Shear Wave Ultrasound Elastographic Study of the Achilles Tendon in Chinese Adults.

Objectives: The changes in the viscoelasticity of the Achilles tendon are related to tendinopathy. Therefore, constructing a data model in the healthy population is essential to understanding the key factors affecting the viscoelasticity of the Achilles tendon. The purpose of our research was to obtain large sample data, construct a data model, and determine parameters that affect the elastic modulus of the Achilles tendon in healthy Chinese adults.

Preferential sensing and response to microenvironment stiffness of human dermal fibroblast cultured on protein micropatterns fabricated by 3D multiphoton biofabrication.

While cells are known to sense and respond to their niche including the matrix and the mechanical microenvironment, whether they preferentially sense and react to the stiffness of their microenvironment regardless of its intrinsic material properties is unknown. In this work, protein micropillar arrays with independently controllable stiffness via alterations in pillar height and elastic modulus via laser power used during photochemical cross-linking, were fabricated using a recently developed multiphoton-based 3D protein micro-patterning technology. Human dermal fibroblasts were cultured on these micropillar arrays and the specific interactions between cells and the protein micropatterns particularly on the formation and maturation of the cell-matrix adhesions, were investigated via immunofluorescence staining of the major molecular markers of the adhesions and the measurement of their cluster size, respectively.

Nanomechanical measurement of adhesion and migration of leukemia cells with phorbol 12-myristate 13-acetate treatment.

The adhesion and traction behavior of leukemia cells in their microenvironment is directly linked to their migration, which is a prime issue affecting the release of cancer cells from the bone marrow and hence metastasis. In assessing the effectiveness of phorbol 12-myristate 13-acetate (PMA) treatment, the conventional batch-cell transwell-migration assay may not indicate the intrinsic effect of the treatment on migration, since the treatment may also affect other cellular behavior, such as proliferation or death. In this study, the pN-level adhesion and traction forces between single leukemia cells and their microenvironment were directly measured using optical tweezers and traction-force microscopy.

Multiphoton photochemical crosslinking-based fabrication of protein micropatterns with controllable mechanical properties for single cell traction force measurements.

Engineering 3D microstructures with predetermined properties is critical for stem cell niche studies. We have developed a multiphoton femtosecond laser-based 3D printing platform, which generates complex protein microstructures in minutes. Here, we used the platform to test a series of fabrication and reagent parameters in precisely controlling the mechanical properties of protein micropillars.