Prasanta is currently working as a Senior Research Fellow (SRF). His research focus has been on developing low cost bioassays for efficient endotoxin detection for early septicemia diagnosis. Sepsis is the leading cause of hospital deaths worldwide which kills more people than breast and prostate cancer combined, mainly due to lack of sensitive and affordable methods for its early detection. Major surgeries, trauma or acute bacterial infections alter the intestinal permeability resulting in the release of intestinal bacteria and their cell wall components like lipopolysaccharides (LPS) into the bloodstream. This triggers a systemic inflammatory response in the body complicated by organ dysfunction, an important hallmark of severe sepsis. Thus, LPS is an important toxin that needs rapid detection for early diagnosis of sepsis (typically within 2 h).
During the course of his thesis, Prasanta has developed three new approaches to identify endotoxin in human serum. The first approach is an ultrasensitive homogeneous agglutination assay (1), the second is a convenient benchtop colorimetric sandwich bioassay (2, 4, 5) and the third is a rapid flow through card test for immediate use by a patient’s bedside (3). All the three formats employ novel antibiotic drug conjugated gold nanoparticles as detection probes and require only a few microliters of blood serum analyte for their final readout.
All the three methods have their own unique merits. The homogeneous format is ultrasensitive while the glass bioassay provides a wide dynamic range without requiring bulky or expensive instrumentation. The test slides can also be stored for several years (in case of future referral) unlike ELISA. The flow through assay by far is the most advanced from a commercialization perspective and can make a huge impact on the way sepsis is diagnosed worldwide. Other potential applications of the bioassays are quality check of pharmaceutical, water and food products.
- Kalita P. and Gupta S., ‘A Nanoparticle-based Homogeneous Bioassay for Ultrasensitive Endotoxin Detection’ Under preparation (2017)
- Kalita P., Bhola A., Goel N., Venkatraman S. and Gupta S., ‘Heterogeneous Endotoxin Detection Bioassay using Drug-nanoparticle Bioconjugates: An Optimization Study’ Under review (2017)
- Kalita S., Chaturvedula M., Sritharan V. and Gupta S., ‘In vitro Flow-Through Assay for Rapid Detection of Endotoxin in Human Sera’ Nanomedicine: Nanotchnology, Biology, and Medicine, 13, 1483-1490 (2017)
- Kalita P., *Dasgupta A. and Gupta S. “Endotoxin Entrapment on Glass via C-18 Self-Assembled Monolayers and Rapid Detection using Drug-Nanoparticle Bioconjugate Probes”, Chap. 13 (133-142), Microbial Toxins: Methods and Protocols (2nd Ed.), MiMB 1600, Springer Protocols (Editor Otto Holst), Humana Press, 2017 (*Equal contribution)
- Kalita P., Dasgupta A., Venkatraman S. and Gupta S., ‘Nanoparticle-drug Bioconjugate as Dual Functional Affinity Ligand for Rapid Detection of Endotoxin in Water and Serum‘ Analytical Chemistry 87, 11007-11012 (2015)