Rational design of a SOCS1-edited tumor-infiltrating lymphocyte therapy using CRISPR/Cas9 screens.

Cell therapies such as tumor-infiltrating lymphocyte (TIL) therapy have shown promise in the treatment of patients with refractory solid tumors, with improvement in response rates and durability of responses nevertheless sought. To identify targets capable of enhancing the antitumor activity of T cell therapies, large-scale in vitro and in vivo clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 screens were performed, with the SOCS1 gene identified as a top T cell-enhancing target. In murine CD8+ T cell-therapy models, SOCS1 served as a critical checkpoint in restraining the accumulation of central memory T cells in lymphoid organs as well as intermediate (Texint) and effector (Texeff) exhausted T cell subsets derived from progenitor exhausted T cells (Texprog) in tumors.

The influence of chondrocyte source on the manufacturing reproducibility of human tissue engineered cartilage.

Multiple human tissue engineered cartilage constructs are showing promise in advanced clinical trials but identifying important measures of manufacturing reproducibility remains a challenge. FDA guidance suggests measuring multiple mechanical properties prior to implantation, because these properties could affect the long term success of the implant. Additionally, these engineered cartilage mechanics could be sensitive to the autologous chondrocyte source, an inherently irregular manufacturing starting material.

Heterogeneous matrix deposition in human tissue engineered cartilage changes the local shear modulus and resistance to local construct buckling.

Human tissue engineered cartilage is a promising solution for focal cartilage defects, but these constructs do not have the same local mechanical properties as native tissue. Most clinically relevant engineered cartilage constructs seed human chondrocytes onto a collagen scaffold, which buckles at low loads and strains. This buckling creates local regions of high strain that could cause cell death and damage the engineered tissue.

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.

High density cell seeding affects the rheology and printability of collagen bioinks.

An advantage of bioprinting is the ability to incorporate cells into the hydrogel bioink allowing for precise control over cell placement within a construct. Previous work found that the printability of collagen bioinks is highly dependent on their rheological properties. The effect of cell density on collagen rheological properties and, therefore, printability has not been assessed.

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.