One of the crucial challenges in the advancement of contemporary medicine is the development of technologies that offer cheap methods for the improvement of health in remote regions in the world. In these disadvantaged areas, hospitals and patients incur a great monetary burden for treatment due to cost of materials, clinical equipment, and operation — luxuries that developing regions cannot easily afford.
The Department of Biomedical Engineering at Columbia University proposed a microfluidic-based device that can diagnose infectious diseases prevalent in these regions, such as HIV or syphilis, at low cost and high success and speed.
Microfluidics concerns manipulation of fluids through highly controlled, geometric constraints. In the case of this device, dubbed the mChip, which was designed by a research team at Columbia University, the microfluidic structure allows for a very small sample of blood to flow through extremely thin channels, where reagents are patterned in to detect disease.
Although microfluidics traditionally involves sophisticated and importable operating equipment, rendering these methods ill-suited for remote settings, the mChip offers easily transported equipment that is able to analyze blood samples in the matter of minutes.
The mChip, which was built to match the size of a credit card, is appropriately designed for places with limited access to medical resources.
The equipment needed for the assay, or the procedure for testing the activity in the substance being examined, includes a mere three items: a plastic tube, a molded plastic card with microfluidic channels built in and a syringe, which costs an aggregate amount of a few pennies.
The device offers very simple use, waiving requirements of any specific expertise pertaining to technology or user interpretation of results. It also offers cheap point-of-care (POC) testing, allowing tests to be performed near the site of patient care instead of designated facilities. Not only is the mChip easily transported, but its manufacturing facilities offer seamless mobility to remote regions. The manufacturing equipment was made as simple as possible, mostly comprised of off-the-shelf material, to offer the same quality to regions worldwide.
Unlike many contemporary microfluidic-based technologies that require hours of assay analysis, the mChip can analyze the blood of patients in less than half an hour. The syringe, one of three items necessary for the assay, is connected to the mChip to pull a several microliters of the patient's blood through the chip. A needle-prick volume of blood is sufficient due to the extreme slimness of the channels. In certain zones of the channels lay a group of proteins that capture specific antibodies which are only present in infected blood.
Antibodies are proteins produced by our immune system that detect specific foreign objects in our body, such as bacteria or viruses. For example, only patients with HIV produce antibodies specific to the virus. Taking advantage of this, the proteins in the mChip bind to specific antibodies, which then bind to other proteins that cover them in silver coating. The analysis of the assay is as simple and logical as determining the concentration of silver in the zone. The more silver, the more antibodies, the larger chance a patient has of being infected.
The mChip assays were conducted in a remote region in Rwanda, where the Columbia University research team collected blood samples from hundreds of local residents and tested for HIV and syphilis simultaneously. The results rivaled those of bench-top assays, indicating easy and cheap POC diagnostic for remote regions of the world.
