Multiscale mechanics of tissue-engineered cartilage grown from human chondrocytes and human-induced pluripotent stem cells.

Tissue-engineered cartilage has shown promising results in the repair of focal cartilage defects. However, current clinical techniques rely on an extra surgical procedure to biopsy healthy cartilage to obtain human chondrocytes. Alternatively, induced pluripotent stem cells (iPSCs) have the ability to differentiate into chondrocytes and produce cartilaginous matrix without the need to biopsy healthy cartilage.

In vitro culture increases mechanical stability of human tissue engineered cartilage constructs by prevention of microscale scaffold buckling.

Many studies have measured the global compressive properties of tissue engineered (TE) cartilage grown on porous scaffolds. Such scaffolds are known to exhibit strain softening due to local buckling under loading. As matrix is deposited onto these scaffolds, the global compressive properties increase.

Correlating rheological properties and printability of collagen bioinks: the effects of riboflavin photocrosslinking and pH.

Collagen has shown promise as a bioink for extrusion-based bioprinting, but further development of new collagen bioink formulations is necessary to improve their printability. Screening these formulations by measuring print accuracy is a costly and time consuming process. We hypothesized that rheological properties of the bioink before, during, and/or after gelation can be used to predict printability.

Mechanical properties and structure-function relationships of human chondrocyte-seeded cartilage constructs after in vitro culture.

Autologous Chondrocyte Implantation (ACI) is a widely recognized method for the repair of focal cartilage defects. Despite the accepted use, problems with this technique still exist, including graft hypertrophy, damage to surrounding tissue by sutures, uneven cell distribution, and delamination. Modified ACI techniques overcome these challenges by seeding autologous chondrocytes onto a 3D scaffold and securing the graft into the defect.

Factors affecting paramagnetic contrast enhancement in synovial fluid: effects of electrolytes, protein concentrations, and temperature on water proton relaxivities from Mn ions and Gd chelated contrast agents.

Introduction: Protein and electrolyte concentration of synovial fluid (SF) varies with the type of underlying arthritis. These characteristics can be utilized by magnetic resonance technology to provide a potentially significant diagnostic modality through quantitative assessments of inherent water relaxation rates and their response to contrast agents.

Methods: We evaluated the effect of a classic "in vitro" contrast agent, the Mn ion, and a common "in vivo" gadolinium based contrast agent, gadopentetate dimeglumine, on the water relaxation times of solutions with biochemical compositions simulating different types of arthritis along with similar studies of SF obtained from patients.