While we’ve seen countless examples of how polymer-based 3D printing processes are helping to produce essential protective gear and other devices for fighting COVID-19 across the globe, there is another aspect of the AM industry which we have not really considered yet in light of the pandemic: bioprinting. While not suitable for producing PPE, bioprinting is reportedly being explored to help in the development of antibodies to the virus. Prellis Biologics, a San Francisco-based bioprinting company, is reportedly exploring the potential of using synthetic bioprinted lymph nodes for the production of fully human antibodies for COVID-19.
Antibodies play a critical role in our immune responses: they are proteins that are used by the immune system to essentially neutralize pathogenic bacteria and viruses. People who have overcome a virus such as COVID-19 will have developed antibodies, which will protect them (at least temporarily) from becoming infected by the virus again. Prellis’ goal is to develop human antibodies which could be administered to people to provide them with temporary immunity to the virus. The bioprinting firm says that antibodies could provide protection for up to three months after injection, which could be especially beneficial for high-risk healthcare workers.
The antibodies created using synthetic lymph nodes bioprinted by Prellis could also act as a prophylactic treatment option for the virus. This, the company explains, would effectively externalize a human’s immune system development. The antibody therapy could also be used to treat COVID-19 patients to minimize the severity of symptoms.
Could synthetic lymph nodes be the answer?
Prellis believes that using its synthetic bioprinted lymph nodes could offer advantages over existing disease-fighting methods, because they enable the disease to be fought outside the body. The company explains: “Prellis Biologics creates synthetic human lymph nodes, the battleground of disease, which can be run cheaply and in large quantities, removing the patient’s body from the equation until an immune response is generated. The resulting immunity is directly injected into the patient. As the disease evolves across the globe, the viruses can be pooled and updated immunity can be provided to patients over time to stay ahead of the virus.”
Because the antibody production process uses synthetic bioprinted lymph nodes, rather than animal organs, the approach is better suited for scalability and is more versatile. The process of creating the antibodies starts with bioprinting the synthetic human lymph nodes, which are then populated with healthy human blood. Prellis says it can print hundreds of miniature lymph nodes to examine immune responses from donors with distinct genetic backgrounds or even different mutations of the virus.
The synthetic lymph nodes are then “vaccinated” after becoming exposed to the virus, and the cells that produce the antibodies divide from non-responding cells, making it possible to isolate them using sorting methods or dilution-based isolation. From there, antibody sequences can be produced in therapeutic quantities in collaboration with biotech or pharmaceutical companies.
“Our process does not require human exposure to a disease, can be scaled up rapidly once the antibody sequence is in hand, is fully human and thus ready for therapeutic use, and does not require blood or plasma from infected individuals,” Prellis adds.
The process itself is not specific to COVID-19: Prellis demonstrated the approach with the Zika virus, producing human antibody hits in just four weeks. Prellis also successfully generated antibodies for human protein CTLA-4 using the approach and received a U.S. patent for the technique in December 2019 and has filed for international patents. Prellis expects to have its COVID-19 antibody production method ready for human trials shortly. From the beginning of the project, it laid out a 10 week plan to reach Phase I clinical human trials.