Pharmaceutics:Microencapsulation technique is used incontrolled/sustained drug delivery. This drugdelivery system may be used in gene therapy,vaccines for treating AIDS, tumors, cancer anddiabetes. Protein such as insulin, growth hormoneand erythropoietin are delivered in a correctivegene sequence in the form of plasmid DNA123.Catalysis:Transition metal based catalytic processes areimportant in pharmaceutical industries. Howevermany of these metals are toxic, making the processhazardous. Microencapsulation enables safehandling, easy recovery, reuse and disposal atcheap cost. Polyurea microcapsules are insoluble inaqueous and organic solvents, and resistanttowards degeneration, therefore theyre used for
the encapsulation of different catalysts such aspalladium, acetate and osmium tetroxide.Energy Generation:Hollow plastic microspheres loaded with gaseousdeuterium are used to obtain electrical energy fromnuclear fusion. The capsules are multilayered.1-Inner layer: Polystyrene shell compressingdeuterium. 3mm thick.2-Middle layer: Polyvnyl alcohol that prevents thediffusion of deuterium out of the capsule. 3mmthick3-Outer layer: Highly crosslinked polymer madefrom 2-butene. 50mm thick.In the fusion experiments, energy from highpowered laser beams is absorbed by the outer shell.The outer shell burns off, and the reaction isaccelerated to the rest of the shell inward,
compressing and heating the deuterium inside. Thisresults in high densities and temperature in thecenter of the capsule leading to the fusion ofdeuterium to give tritium, helium and otherparticles, releasing an enormous amount of energy.Defence:Self-healing polymers is one of the most importantdefence applications of microencapsulation. Theyprovide long-lived structural materials and store thehealing agent during quiescent states and alsoprovide the mechanical trigger for the self-healingprocess when damage occurs in the host material.To provide long shelf life the capsules must beimpervious to leakage and diffusion of theencapsulated healing agent for considerable time.The addition of these microcapsules to an epoxymatrix also provides a unique tougheningmechanism for the composite system. Suchmicrocapsules have tremendous application in
aerospace area for making self-repairablespacecrafts. Such self-healing spacecrafts open upthe possibility of longer duration missions byincreasing the lifetime of a spacecraft.Microencapsulation is also used for designingspecialized fabrics for military personnel, for theirenhanced chemical protection against chemicalwarfare.Agriculture:Insect pheromones may serve as an alternative toconventional hard pesticides, such as sexattractantpheromones that reduce populations by disruptingthe insects mating process by hiding thepheromone plume released by its femalemate.Polymer microcapsules, polyurea, gelatin andgum arabic are used as delivery vehicles by sprayingthe capsule dispersion. They also protect thepheromone from oxidation and light during storageand release.
Food Industry:Microencapsulation enables food companies toincorporate minerals, vitamins, flavours andessential oils. It can also simplify the foodmanufacturing process by converting liquids intosolid powder which decreases the cost andequipment power. It also helps fragile and sensitivematerials by stabilizing their shelf life.