1. 'Killer' Microcapsules That Can Selectively Destroy Target Microparticles in Their Vicinity
- Author
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Srinivasa R. Raghavan, Chandamany Arya, and Hyuntaek Oh
- Subjects
Materials science ,Alginates ,Ionic bonding ,Capsules ,02 engineering and technology ,engineering.material ,010402 general chemistry ,01 natural sciences ,Chitosan ,Glucose Oxidase ,chemistry.chemical_compound ,Biopolymers ,Glucuronic Acid ,General Materials Science ,Glucose oxidase ,Chelation ,biology ,Hexuronic Acids ,Microbead (research) ,021001 nanoscience & nanotechnology ,Natural killer T cell ,0104 chemical sciences ,chemistry ,Biochemistry ,Glutaral ,Biophysics ,biology.protein ,engineering ,Biopolymer ,Glutaraldehyde ,0210 nano-technology - Abstract
We have developed microscale polymer capsules that are able to chemically degrade a certain type of polymeric microbead in their immediate vicinity. The inspiration here is from the body’s immune system, where killer T cells selectively destroy cancerous cells or cells infected by pathogens while leaving healthy cells alone. The “killer” capsules are made from the cationic biopolymer chitosan by a combination of ionic cross-linking (using multivalent tripolyposphate anions) and subsequent covalent cross-linking (using glutaraldehyde). During capsule formation, the enzyme glucose oxidase (GOx) is encapsulated in these capsules. The target beads are made by ionic cross-linking of the biopolymer alginate using copper (Cu2+) cations. The killer capsules harvest glucose from their surroundings, which is then enzymatically converted by GOx into gluconate ions. These ions are known for their ability to chelate Cu2+ cations. Thus, when a killer capsule is next to a target alginate bead, the gluconate ions diffuse...
- Published
- 2016