Secretion and Reversible Assembly of Extracellular-like Matrix by Enzyme-Active Colloidosome-Based Protocells

The secretion and reversible assembly of an extracellular-like matrix by enzyme-active inorganic protocells (colloidosomes) is described. Addition of N-fluorenyl-methoxycarbonyl-tyrosine-(O)-phosphate to an aqueous suspension of alkaline phosphatase-containing colloidosomes results in molecular uptake and dephosphorylation to produce a time-dependent sequence of supramolecular hydrogel motifs (outer membrane wall, cytoskeletal-like interior and extra-protocellular matrix) that are integrated and remodelled within the microcapsule architecture and surrounding environment. Heat-induced disassembly of the extra-protocellular matrix followed by cooling produces colloidosomes with a densely packed hydrogel interior. These procedures are exploited for the fabrication of nested colloidosomes with spatially delineated regions of hydrogelation

Bioactive Hybrid Organogels Based on Miniemulsion Synthesis of Morphologically Complex Polymer/Surfactant/Calcium Phosphate Nanostructures

Morphologically complex amorphous calcium phosphate nanostructures are synthesized within supersaturated water-in-oil miniemulsions stabilized by a mixture of a calcium bis­(2-ethylhexyl)­phosphate (Ca­(DEHP)₂) surfactant and poly­(ethylene oxide)₁₉-poly­(propylene oxide)₆₉-poly­(ethylene oxide)₁₉ (P123) triblock copolymer. Solvent evaporation at room temperature results in self-supporting viscous organogels comprising an interconnected network of calcium phosphate nanofilaments embedded within a continuous polymer/surfactant matrix. The P123/DEHP/calcium phosphate organogels are employed as a bioactive filler for the occlusion of exposed dentine tubules using a standard bovine tooth model