Robust and Long-Term Cellular Protein and Enzymatic Activity Preservation in Biomineralized Mammalian Cells.

Preservation of evolved biological structure and function in robust engineering materials is of interest for storage of biological samples before diagnosis and development of vaccines, sensors, and enzymatic reactors and has the potential to avoid cryopreservation and its associated cold-chain issues. Here, we demonstrate that "freezing cells in amorphous silica" is a powerful technique for long-term preservation of whole mammalian cell proteomic structure and function at room temperature. Biomimetic silicification employs the crowded protein microenvironment of mammalian cells as a catalytic framework to proximally transform monomeric silicic acid into silicates forming a nanoscopic silica shell over all biomolecular interfaces.

SupraCells: Living Mammalian Cells Protected within Functional Modular Nanoparticle-Based Exoskeletons.

Creating a synthetic exoskeleton from abiotic materials to protect delicate mammalian cells and impart them with new functionalities could revolutionize fields like cell-based sensing and create diverse new cellular phenotypes. Herein, the concept of "SupraCells," which are living mammalian cells encapsulated and protected within functional modular nanoparticle-based exoskeletons, is introduced. Exoskeletons are generated within seconds through immediate interparticle and cell/particle complexation that abolishes the macropinocytotic and endocytotic nanoparticle internalization pathways that occur without complexation.

Metal-Organic Framework Nanoparticle-Assisted Cryopreservation of Red Blood Cells.

The development of hybrid nanomaterials mimicking antifreeze proteins that can modulate/inhibit the growth of ice crystals for cell/tissue cryopreservation has attracted increasing interests. Herein, we describe the first utilization of zirconium (Zr)-based metal-organic framework (MOF) nanoparticles (NPs) with well-defined surface chemistries for the cryopreservation of red blood cells (RBCs) without the need of any (toxic) organic solvents. Distinguishing features of this cryoprotective approach include the exceptional water stability, low hemolytic activity, and the long periodic arrangement of organic linkers on the surface of MOF NPs, which provide a precise spacing of hydrogen donors to recognize and match the ice crystal planes.

Modular Metal-Organic Polyhedra Superassembly: From Molecular-Level Design to Targeted Drug Delivery.

Targeted drug delivery remains at the forefront of biomedical research but remains a challenge to date. Herein, the first superassembly of nanosized metal-organic polyhedra (MOP) and their biomimetic coatings of lipid bilayers are described to synergistically combine the advantages of micelles and supramolecular coordination cages for targeted drug delivery. The superassembly technique affords unique hydrophobic features that endow individual MOP to act as nanobuilding blocks and enable their superassembly into larger and well-defined nanocarriers with homogeneous sizes over a broad range of diameters.