Secreted Products from the Porcine Choroid Plexus Accelerate the Healing of Cutaneous Wounds

Cell encapsulation: Overcoming barriers in cell transplantation in diabetes and beyond

Cell-based therapy is emerging as a promising strategy for treating a wide range of human diseases, such as diabetes, blood disorders, acute liver failure, spinal cord injury, and several types of cancer. Pancreatic islets, blood cells, hepatocytes, and stem cells are among the many cell types currently used for this strategy. The encapsulation of these "therapeutic" cells is under intense investigation to not only prevent immune rejection but also provide a controlled and supportive environment so they can function effectively. Some of the advanced encapsulation systems provide active agents to the cells and enable a complete retrieval of the graft in the case of an adverse body reaction. Here, we review various encapsulation strategies developed in academic and industrial settings, including the state-of-the-art technologies in advanced preclinical phases as well as those undergoing clinical trials, and assess their advantages and challenges. We also emphasize the importance of stimulus-responsive encapsulated cell systems that provide a "smart and live" therapeutic delivery to overcome barriers in cell transplantation as well as their use in patients.

Primary Choroid Plexus Tissue for Use in Cellular Therapy

The choroid plexus (CP) has been explored as a cellular therapeutic due to its broad-ranging secretome and demonstrated longevity in a variety of encapsulation modalities. While the CP organ is normally involved in disease repair processes in the brain, the range of indications that could potentially be ameliorated with exogenous CP therapy is widespread, including diseases of the central nervous system, hearing loss, chronic wounds, and others. The CP can be isolated from animal sources and digested into a highly purified epithelial culture that can withstand encapsulation and transplantation. Its epithelium can adapt to different microenvironments, and depending on culture conditions, can be manipulated into various three-dimensional configurations with distinct gene expression profiles. The cocktail of proteins secreted by the CP can be harvested in culture, and purified forms of these extracts have been evaluated in topical applications to treat poorly healing wounds. When encapsulated, the epithelial clusters can be maintained for extended durations in vitro with minimal impact on potency. A treatment for Parkinson's disease utilizing encapsulated porcine CP has been developed and is currently being evaluated in a Phase I clinical trial. The current chapter serves to summarize recent experience with CP factor delivery, and provides a description of the relevant materials and methods employed in these studies.

Functional modulation of choroid plexus epithelial clusters in vitro for tissue repair applications

One of the primary obstacles in the restoration or repair of damaged tissues is the temporospatial orchestration of biological and physiological events. Cellular transplantation is an important component of tissue repair as grafted cells can serve as replacement cells or as a source of secreted factors. But few, if any, primary cells can perform more than a single tissue repair function. Epithelial cells, derived from the choroid plexus (CP), are an exception to this rule, as transplanted CP is protective and regenerative in animal models as diverse as CNS degeneration and dermal wound repair. They secrete a myriad of proteins with therapeutic potential as well as matrix and adhesion factors, and contain responsive cytoskeletal components potentially capable of precise manipulation of cellular and extracellular niches. Here we isolated CP from neonatal porcine lateral ventricles and cultured the cells under a variety of conditions to specifically modulate tissue morphology (2D vs. 3D) and protein expression. Using qRT-PCR analysis, transmission electron microscopy, and gene microarray studies we demonstrate a fine level of control over CP epithelial cell clusters opening further opportunities for exploration of the therapeutic potential of this unique tissue source.