What is Theranostics?

Theranostics is a term derived from a combination of the words therapeutics and diagnostics. In this emerging field of medicine, drugs and/or techniques are uniquely combined to simultaneously or sequentially diagnose and treat medical conditions.

The ability to acquire a diagnosis and administer therapy in one package is a game-changer for medicine as we know it. Not only does this offer the opportunity to save time and money, but it also potentially allows one to bypass some of the undesirable biological effects that may arise when these strategies are employed separately.  

Theranostics and Nanomedicine

The medical application of nanotechnology is referred to as nanomedicine, and this is made possible by a vast range of medical and scientific methodologies. One such approach is the use of nanoparticles in theranostics. The ultimate aim of combining nanomedicine and theranostics is to modify disease and patient-specific outcomes in such a way that they are drastically improved.

Owing to their high potential to target specific organs or tissues, as well as their capacity to be manipulated with multifunctionality, nanoparticles possess significant advantages that are brilliantly suitable for employment in theranostic medicine.

In line with the preceding statement, nanoparticles are able to target diseased areas within the body, thereby avoiding damage to healthy tissues. Once the area of interest has been pinpointed, nanoparticles may then provide information on the extent of the disease, and even indicate disease response to treatment, if applicable. After acquisition of this information, nanoparticles may then proceed with the delivery of the therapy as needed.

Based on responses to internal or external stimuli, these nanoparticles are capable of administering exact concentrations of the required therapeutic agents. Furthermore, they can play an additional role in the monitoring of the drug delivery, release and efficacy.

Nanoparticles are capable of evading premature destruction or degradation by physiological processes, unlike many conventional drug therapies. Moreover, the  high surface to volume ratios seen with nanoparticles allows them to transport more diverse substances with the use of less extraneous material. In particular, nanoparticles may be exceptionally used in the diagnosis and treatment of cancers.

They are ideal in this regard, because they are capable of rapidly and selectively accumulating at cancer-specific sites, and once there, emitting signals based on their specific biomarkers, subsequently to deliver the necessary therapy according to the data that they acquired.

The Application of Theranostics in Cancer  

Cancer is a tricky entity, because it is not just one disease, but a heterogenous group of diseases that is characterized by uncontrolled and rapid cell growth. This is usually due to genetic and/or epigenetic changes in affected patients. Current therapies for cancer include chemotherapy, radiotherapy, immunotherapy and surgery.

Chemotherapy in particular has limited usefulness owing to the reduced concentration of drug molecules that reach the tumors which they are intended to treat. Further limitations of chemotherapy include the development of resistance to treatment during therapy, and of course the many side effects associated with the drugs used.

Here nanomedicine with the help of nanoparticles shows great potential in addressing the limitations of conventional treatment. These particles allow molecular targeting to ensure higher concentrations of drug molecules at the tumor site. This has been the focus of extensive studies on drug delivery systems which incorporate nanotechnology, in recent years. These studies investigate the use of nanomedicines in an active or passive manner to trigger site-specific release of drugs. This ensures that the drug bypasses tissues that are off-target, and in doing so improves the therapeutic index.

Some examples of nanomedicines that are of significant clinical relevance are polymeric micelles, polymer-drug conjugates and liposomes. In contrast to traditional small molecular drugs that are quickly eliminated from the bloodstream, nanomedicines have longer half-lives.

This is in addition to their better bioavailability and augmented tumor delivery.  Moreover, the possibility for integrating imaging into nanomedicine will assist with the diagnostic arm of theranostics. The advantages of employing such a strategy are vast, and would enable us to make great strides in the management of oncogenic conditions with theranostics.

Further Reading

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Written by

Dr. Damien Jonas Wilson

Dr. Damien Jonas Wilson is a medical doctor from St. Martin in the Carribean. He was awarded his Medical Degree (MD) from the University of Zagreb Teaching Hospital. His training in general medicine and surgery compliments his degree in biomolecular engineering (BASc.Eng.) from Utrecht, the Netherlands. During this degree, he completed a dissertation in the field of oncology at the Harvard Medical School/ Massachusetts General Hospital. Dr. Wilson currently works in the UK as a medical practitioner.