Chou, D. B. | Search bioRxiv

bioRxiv2018

Probiotic Associated Therapeutic Curli Hybrids (PATCH)

There is an unmet need for new treatment methods for inflammatory bowel disease (IBD) that can reliably maintain remission without leading to detrimental side effects. Beneficial bacteria have been utilized as an alternative treatment for IBD albeit with low efficacy. We genetically engineered Escherichia coli Nissle 1917 (EcN) to create an anti-inflammatory fibrous matrix in situ. This matrix consists of EcN-produced curli nanofibers displaying trefoil factors (TFFs), known to promote intestinal barrier function and epithelial restitution. We confirmed that engineered EcN was able to secrete the curli-fused TFFs in vitro and in vivo, and was non-pathogenic. We observed an enhanced protective effect of engineered EcN against dextran sodium sulfate induced colitis in mice, associated with barrier function reinforcement and immunomodulation. This work sets the foundation for the development of a novel therapeutic platform in which the in situ production of a therapeutic protein matrix from beneficial bacteria can be exploited.

bioengineering↗

bioRxiv2018

Human bone marrow disorders recapitulated in vitro using organ chip technology

Understanding human bone marrow (BM) pathophysiology in the context of myelotoxic stress induced by drugs, radiation, or genetic mutations is of critical importance in clinical medicine. However, study of these dynamic cellular responses is hampered by the inaccessibility of living BM in vivo. Here, we describe a vascularized human Bone Marrow-on-a-Chip (BM Chip) microfluidic culture device for modeling bone marrow function and disease states. The BM Chip is comprised of a fluidic channel filled with a fibrin gel in which patient-derived CD34+ cells and bone marrow-derived stromal cells (BMSCs) are co-cultured, which is separated by a porous membrane from a parallel fluidic channel lined by human vascular endothelium. When perfused with culture medium through the vascular channel, the BM Chip maintains human CD34+ cells and supports differentiation and maturation of multiple blood cell lineages over 1 month in culture. Moreover, it recapitulates human myeloerythroid injury responses to drugs and gamma radiation exposure, as well as key hematopoietic abnormalities found in patients with the genetic disorder, Shwachman-Diamond Syndrome (SDS). These data establish the BM Chip as a new human in vitro model with broad potential utility for studies of BM dysfunction.

bioengineering↗