The need of micro-physiological systems for COVID19Recognizing the need for more efficient testing of potential vaccines or other treatments for COVID19 the NIH has announced an SBIR grant for the use of micro-physiological systems. These microfluidic tools allow simulation of the human physiology for studies of toxicity or efficacy. Several commercial models are found on this site here.
The lengthy clinical tests vaccines are one of the major contributors to the process of vaccine development typically taking 10-15 years. Testing for safety and efficiency for COVID-19 treatments are being done on patients, which is a very risky and inefficient process. Testing in model systems that replicate physiology would be preferable on many levels.
There are few micro-physiological systems available commercially, and few of those can apply to this challenge. One of the suitable platforms is PerfusionPal from Lena Biosciences.
The system allows perfusion of 3D tissues, allowing them to be oxygenated efficiently. The ingenious principle uses a fluorocarbon fluid which has significantly greater capacity to carry oxygen than water and is completely immiscible with it. This liquid acts as a flexible and sterile piston, which drives the media solutions through the porous inserts holding cells.
This system can be used to grow tissue for days with minimal attendance in high-throughput (12- or 48-well plates). Using lung cells expressing ACE2 receptor, which SARS-CoV-2 uses to gain entry to cells in both lower and upper respiratory tracts, can help to study infection or to create a model infected system.
The “substitute blood” fluorocarbon fluid has a very interesting property, which could be of interest when studying respiratory infections. This fluid is “breathable” and can be breathed like amniotic fluid in the womb. Air-breathing animals are able to breathe this fluid, which is call “liquid ventilation”. Since the liquid is heavy, it descends through the lungs to open the areas of atelectasis and could potentially help people breathe, while reducing the possibility of COVID-19 spreading through the lungs. Such techniques are used to save neonates (under-term babies with under-developed lungs), so there is a possibility that this technique could have impact on COVID-19 respiratory failure.
Another tissue of interest is neural. Unfortunately, there is strong evidence of neuro-invasiveness of SARS-CoV-2 that suggests greater efforts should be directed to study tropism of this virus in nerve cells, including receptors used to gain entry to this cell type.
In summary MPS are enabling tools that can testing toxic or ineffective medicines on people who need them most and to replace them with high throughput, miniaturized and efficient microfluidics platforms.