nanocapsule (rus. нанокапсула otherwise коллоидосома) — a nanoparticle comprised of a polymer, lipid or other type of shell that enclosing its inner cavity or content.

Description

A nanocapsule is usually a hollow spherical particle made up of polymers or phospholipids (in this case it is called a liposome or a nanosome) containing a low-molecular substance inside. The shell of a nanocapsule may be fabricated from other materials, such as hydroxyapatite or calcium silicate, as well as from specifically organised DNA molecules. A nanocapsule must be chemically stable, bioactive, biocompatible and capable of protecting the encapsulated material against undesirable effects, such as dissolution in liquids. The maximum size of a nanocapsule is usually 100 nm, and a microcapsule – 600 um. Nanocapsules have a high penetration capability and may penetrate even such “closed” areas of a body as the brain.

Nanocapsules are used for the controlled delivery of encapsulated bioactive substances, such as drugs (including water-insoluble or unstable), peptides and proteins (hormones or cytokines), as well as the delivery of genes encoding enzymes, hormones and cytokines. A wide range of substances can be encapsulated , from cancer therapeutics and bone morphogenic protein to beauty therapy products. To enable the targeted delivery of a substance, the nanocapsule's surface may be modified with specific antigens, receptors or ligands. Liposomes are one of the most convenient types of nanocapsule. A liposome membrane is made up of natural phospholipids, which allows it to be absorbed by cells in certain conditions. The liposome membrane can fuse with the cell membrane, enabling cellular delivery of the liposome's contents. Delivery of nanocapsules inside the red blood cells and bacteria also shows great promises.

The encapsulation of drugs inside nanocapsules facilitates the use of many instable or water-insoluble drug compounds. Liposomes (nanosomes) can be used for encapsulation of water-soluble drugs, and polymer nanocapsules are generally used to encapsulate hydrophobic compounds. Drug encapsulation reduces toxic effects and improves pharmacokinetics. Now approaches are being developed to use nanocapsules for the transportation of nanostructures with metallic and semiconductor properties, as well as super-paramagnetic nanoparticles for the selective destruction of tumour cells exposed to electromagnetic heating (see hyperthermia). 

Authors

  • Naroditsky Boris S.
  • Shirinsky Vladimir P.
  • Shlyakhtin Oleg A.
  • Nesterenko Lyudmila N.

Sources

  1. Schwarz J. A., Contescu C., Putyera K. Dekker encyclopaedia of nanoscience and nanotechnology. — CRC Press, 2004. — 2739 p.
  2. B. Glick, J. Pasternak. Molecular Biotechnology: Principles and Applications of Recombinant DNA. — 3rd ed. Sigma Publishing, 2003, 784 pp.

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