The following research descriptions reflect my NIH biosketch|
Microscale biosensors for HIV detection and viral load determination
The Human Immunodeficiency Virus (HIV) pandemic has resulted in more than 34 million deaths worldwide and another 37 million people are living with HIV today. Among the barriers to bringing the standard of care to those facing HIV infection is the limited availability of technologies to meet the needs of diagnosis and clinical monitoring, particularly viral load quantification. Recent understanding has underscored the importance of viral load as a core marker in clinical management, not only for maintaining the health of the HIV-positive individual, but also in preventing transmission of the virus to others.
In this work, we developed approaches to detection and quantification of HIV from whole blood samples. First, we developed a technique called ion-release impedance spectroscopy which employs a simple ion-filled liposome as the signal component of a microfluidic immuno-capture and impedance-based biosensor. More recently, we have implemented an alternative approach which employs loop-mediated isothermal amplification (RT-LAMP) for detection of viral RNA in a whole blood sample. A major aspect of the novelty of the RT-LAMP approach was to show the potential for direct detection in lysed whole blood with limited sample processing. The reaction was demonstrated in nanoliter droplets and imaged with a consumer smartphone.
This work was the focus of my doctoral thesis which I led and developed with support of colleagues in the laboratory of Dr. Rashid Bashir in the Department of Bioengineering at the University of Illinois at Urbana-Champaign.
An impedance-based microfluidic cytometer for blood cell enumeration
Blood cell counting is ubiquitous in healthcare; however, the use of blood counts in clinical diagnostics is currently limited to settings which have established infrastructure for central sample processing and reporting. Our work has addressed two specific areas in which point-of-care blood cell counting could improve the standard of care for millions of individuals worldwide: in management of HIV infection and basic applications of the complete blood count.
The core technology is a microfluidic cytometer designed to receive a 10 microliter whole blood input (as from a fingerstick). Selective cell lysis and dilution of the sample is performed on-chip in precisely-controlled microfluidic channels followed by impedance-based cell counting which is capable of distinguishing many blood cell types based on size and membrane properties. Further discrimination of cell sub-type (e.g. CD4+ T lymphocyte enumeration) is achieved with immune-affinity capture in an antibody-functionalized microfluidic chamber which, coupled with pre-capture and post-capture cell counting allows for a differential count of specific populations of interest. Future work aims to apply this core technology to bedside detection of novel biomarkers of inflammatory response in medical and intensive care of the hospitalized patient.
This work was a part of my graduate training at the University of Illinois at Urbana-Champaign in the laboratory of Dr. Rashid Bashir, where I was part of a team led by Dr. Nicholas Watkins and Dr. Umer Hassan.