Theranostics for cancer therapy.

With over 10 million new cases per year worldwide, Cancer remains one of the most urgent health concerns and a difficult disease to treat. For an effective treatment, improved diagnostic and therapeutic techniques with minimal side-effects are required. Research and development in the areas of nanoscience and nanotechnology promise to provide innovative and more effective approaches for early diagnosis, imaging and therapy. An emerging trend in this direction is Theranostics which represents a combinatorial diagnosis and therapeutic approach to cancer disease and aims to eliminate multi-step procedures, reduce delays in treatment and improves patient care. It offers various advantages like improved diagnosis, tumor specific delivery of drugs, reduced lethal effects to normal tissues etc. Theranostic nanomedicines like nanoshells, plasmonic nanobubbles, quantum dots etc. can be used effectively for achieving these goals. With the advances in nano-imaging and nano-therapy new avenues for the development of effective cancer treatment will be opened.

Microbubbles and their applications in pharmaceutical targeting.

Microbubbles are small spherical gas filled bubbles in the size range of 1-10 microns. Their external coat is made of polymers or phospholipids. In combination with ultrasound, they have been explored as contrast agents for ultrasound and also carriers for drug and gene delivery. In response to ultrasound of lower mechanical index, microbubbles oscillate and vibrate to give a distinct signal in ultrasound imaging. At a higher mechanical index, these microbubbles rupture and break to deliver the drugs or genes enclosed in them or attached to their surface. The behaviour of microbubbles in response to ultrasound is a characteristic of the properties of microbubbles like its shell composition, shell thickness and the density and compressibility of the enclosed gas. Microbubbles have various applications in diagnostic imaging like echocardiography, and imaging of cancer cells, inflammed cells etc. They are also used as a medium for drug and gene delivery. Microbubbles can be further modified by binding specific ligands to their surface which specifically attach to certain cells so that selective action of the microbubbles can be seen at that location of cells.