Tuning viscoelasticity and stiffness in bioprinted hydrogels for enhanced 3D cell culture: A multi-scale mechanical analysis.

Bioprinted hydrogels are extensively studied to provide an artificial matrix for 3D cell culture. The success of bioprinting hydrogels relies on fine-tuning their rheology and composition to achieve shear-thinning behavior. However, a challenge arises from the limited viscoelastic and stiffness range accessible from a single hydrogel formulation.

Quantification of cell contractile behavior based on non-destructive macroscopic measurement of tension forces on bioprinted hydrogel.

Contraction assay based on surface measurement have been widely used to evaluate cell contractility in 3D models. This method is straightforward and requires no specific equipment, but it does not provide quantitative data about contraction forces generated by cells. We expanded this method with a new biomechanical model, based on the work-energy theorem, to provide non-destructive longitudinal monitoring of contraction forces generated by cells in 3D.

Human dentin characteristics of patients with osteogenesis imperfecta: insights into collagen-based biomaterials.

Osteogenesis imperfecta (OI), also known as "brittle bone disease", is a rare genetic disorder of the skeleton, whose most benign form I corresponds to autosomal dominant mutations in the genes encoding type I collagen (COLA1, COLA2). Several associated skeletal manifestations are often observed but, surprisingly, while dentin defects often reflect genetic bone disorders, about half of OI patients have no obvious oral manifestations. Here, we investigated the collagen, mineral and mechanical properties of dentin from deciduous teeth collected from patients with mild form of OI and displaying no obvious clinical signs of dentinogenesis imperfecta.

Mechanical alterations of the bone-cartilage unit in a rabbit model of early osteoarthrosis.

Objective: The purpose of this study was to assess mechanical properties along with microstructural modifications of the hyaline cartilage (HC), calcified cartilage (CC) and cortical plate (Ct.Pt), in an anterior cruciate ligament transection (ACLT) model. Medial femoral condyles of six healthy rabbits (control group) and of six ACLT rabbits 6 weeks after OA induction were explanted.