Abstract: The present invention contemplates induction of immunological tolerance thereby providing permanent allogcaft acceptance. This method obviates the need for a lifelong regimen of immunosuppressive agents which can increase the risk of infection, autoimmunity, and cancer. Immunological tolerance is thought to be mediated by regulatory T lymphocytes (Treg cells) with immunosuppressive capabilities. A therapeutically relevant platform comprising artificial constructs are contemplated comprising numerous soluble and surface bound Treg cell stimulating factors that may induce tolerance following allograft transplantation. Such artificial constructs, being the size of a cell, have surface bound monoclonal antibodies specific to regulatory T-cell surface moieties and encapsulated soluble regulatory T-cell modulating factors.

Abstract: A drug delivery system comprising pH triggerable particles is described. The pH triggerable particles comprise and agent(s) to be delivered, which is encapsulated in a matrix comprising a pH trigger agent and a polymer. Agents including nucleic acids may be delivered intracellularly using the inventive pH triggerable particles. Upon exposure to an acidic environment such as the endosome or phagosome of a cell, the particles dissolve or disrupt due to protonation or an increase in solubility of the pH triggering agent. Pharmaceutical compositions and methods of preparing and administering these particles are also described. These particles may be particularly useful in genetic vaccination.

Abstract: Provided are tubular structures of a biocompatible, triggerably-dissolvable material such as cellulose or a copolymer having an LCST below physiological temperatures. The structures may be embedded within a cell growth scaffold. The tubular structures are useful in growing 3-dimensional tissue structures because nutrients, cytokines or other cell growth and/or differentiation compounds, as well as drugs, such as antibiotics and steroids, can be administered over time, and the tubular structures can be dissolved non-invasively.