Endothelial cell membrane-based biosurface for targeted delivery to acute injury: analysis of leukocyte-mediated nanoparticle transportation.

Mimicking and leveraging biological structures and materials provide important approaches to develop functional vehicles for drug delivery. Taking advantage of the affinity and adhesion between the activated endothelial cells and innate immune cells during inflammatory responses, hybrid polyester nanoparticles coated with endothelial cell membranes (EM-P) containing adhesion molecules were fabricated and their capability as vehicles to travel to the acute injury sites through leukocyte-mediated processes was investigated. The studies and quantitative analyses performed through the lung-inflammation mouse models demonstrated that the EM-Ps preferentially interacted with the neutrophils and monocytes in the circulation and the cellular membrane-based biosurface improved the nanoparticle transportation to the inflamed lung possibly the motility of neutrophils.

Mesenchymal stromal exosome-functionalized scaffolds induce innate and adaptive immunomodulatory responses toward tissue repair.

Designing scaffolds capable of inducing and guiding appropriate immune responses holds promise for tissue repair/regeneration. Biofunctional scaffolds were here prepared by immobilizing mesenchymal stromal exosomes onto fibrous polyester materials and allowed cell-mediated delivery of membrane-bound vesicles. Quantitative cell-level analyses revealed that immune cells dominated the uptake of exosomes from scaffolds in vivo, with materials and exosomes acting as the recruiter and trainer for immune cells, respectively, to synergistically promote beneficial macrophage and regulatory T cell responses in skin wounds in mice.

From Micro to Macro: The Hierarchical Design in a Micropatterned Scaffold for Cell Assembling and Transplantation.

A microwell-patterned membranous scaffold that integrates nano- and microscale topographical characteristics based on polyurethane is fabricated for transplanting syngeneic islets and allogeneic mesenchymal stem cells into diabetic rodents. The scaffold effectively allows for assembling of single cells/microtissues, enables the transplantation of cells with spatial control, and improves the transplant's engraftment efficacy in vivo for treating diabetes.

Overcoming foreign-body reaction through nanotopography: Biocompatibility and immunoisolation properties of a nanofibrous membrane.

Implantable immunoisolation membranes need to possess superior biocompatibility to prohibit the fibrotic deposition that would reduce the nutrient supply and impair the viability/function of the encapsulated cells. Here, electrospun membranes based on thermoplastic polyurethane (TPU) were fabricated to contain microfibers (PU-micro) or nanofibers (PU-nano). The two types of membranes were compared in terms of their interaction with macrophage cells and the host tissues.