Nanotechnology based targeted drug delivery.

NANOTECHNOLOGY is having a great impact on many industrial applications, such as manufacturing, semiconductors, nanostructured materials and biotechnology. As relates to the latter, nanobiotechnology focuses on the ability to work at the molecular and atomic level to fabricate structures combining biological materials and synthetic materials, taking into account engineering, physics, chemistry, genomics and proteomics. The main goals relate to biosensors, nanosized microchips, and more generally to medical applications at the molecular level. Nanotechnology has been recently extensively applied to treatment and diagnosis of diseases and the new term nanomedicine has been introduced, for which several definitions have so far been proposed [1]-[3] which focus on the use of engineered nano-devices and nanostructures for diagnosis and treatment. One of the key aspects of nanomedicine is targeted drug delivery by nanoscale drug carriers. At present, 95 \% of all new potential therapeutics have poor pharmaco kinetics and biopharmaceutical properties, there is therefore a great need to develop drug delivery [4] systems that convey the therapeutically active molecules only to the site of action, without affecting other organs and tissues [5]. This allows to lower required doses of drugs and to increase their therapeutic indices and safety profiles. It is possible to fabricate nanoparticles or nanocapsules with different properties as relates to drug encapsulation and release. A great amount of nanoscale systems for drug delivery has been investigated; they include liposomes, dendrimers, quantum dots, nanotubes, polymeric biodegradable nanoparticles and nanocapsules [6].