Biomarkers are the Holy Grail for
detecting diseases. Natural biomarkers are sought after molecules for effective
screening of patients. Biomarkers include detection of proteins, RNA, DNA to
now even micro RNAs. However, detection of natural biomarkers is fraught with
issues of specificity, feasibility , price etc.
Now, a new set of research is
employing the idea of nano-particles conjugated peptides. Since many disease
states are characterized by dysregulated protease activity, the synthetic probe
acts by stimulating this response thereby releasing the peptides that can be
non-invasively detected. The nanoparticle is introduced and allowed to
accumulate in diseased tissue where it is cleaved by the overactive proteases.
This cleavage releases the peptides into the host’s urine, where it can be
detected using either simple ELISA or mass spectrometry. Synthetic biomarkers
provide the flexibility, ease and specificity that a modern day diagnostic lab
would demand. In fact, promising results have already been observed to monitor
liver fibrosis and detect early stage cancer. This noninvasive urinary
monitoring could prove applicable to many diseases that feature protease
dysregulation, including cancer, atherosclerosis, inflammation, and Alzheimer’s
disease and may also detect many of these diseases much earlier than the
traditional biomarkers.
Image - ACS Nano, 2013, 7 (10), pp 9001–9009
The recent news of a paper based assay to detect cancer (colorectal at this point of time) and thrombosis is a very important step in the direction of non-invasive ‘synthetic biomarker’
based diagnostics. This is even more significant for poor countries where
population cannot afford high cost diagnostics that might not even be accurate
enough for the cost of the assay. Therefore, I believe the field of
nano-particles and synthetic biomarkers can be given more encouragement not
only from the Government but also from the various aid agencies to improve upon
the technology and help bring the products to the market much faster.