Additive Manufacturing for Fabrication of Point-of-Care Therapies in Austere Environments
Authors: Barnhill Jason , Gaston Joel D , Deffenbaugh Paul I , Wagner Linzie , Liacouras Peter C , Ho Vincent B 
Published: February 2023

ABSTRACT

Introduction
Known as the “golden hour,” survival of most critically injured patients is highly dependent on providing the required treatment within the first hour of injury. Recent technological advances in additive manufacturing (also known as three-dimensional [3D] printing) allow for austere deployment and point-of-care rapid fabrication of a variety of medical supplies, including human tissues and bioactive bandages, in prolonged field care scenarios. In this pilot project, our aim was to investigate the ability to 3D print a range of potential biomedical supplies and solutions in an austere field environment.

Materials and Methods
We specifically designed and fabricated novel surgical tools, bioactive bandages, objects (screw and anatomic models), and human meniscal tissue in an austere African desert environment. A total of seven packages were sent using a commercial carrier directly to the end destination. A multi-tool ruggedized 3D printer was used as the manufacturing platform for all objects fabricated downrange. Human mesenchymal stem cells were shipped for 3D bioprinting of human menisci and bioactive bandages. Design and fabrication for all 3D-printed products utilized computer-aided design (CAD) tools.

Results
Initial shipment from a single U.S. site to the sub-Saharan Africa location was relatively prompt, taking an average of 4.7 days to deliver three test packages. However, the actual delivery of the seven packages from Orlando, FL, to the same sub-Saharan Africa site took an average of 16 days (range 7-23 days). The ruggedized printer successfully fabricated relevant medical supplies using biocompatible filament, bioink hydrogels, and stem cell–loaded bioinks. This prototype did not, however, have the capacity to provide a sterile environment. A multi-material complete bandage was 3D printed using polyamide polyolefin and cellulose, live cells, neomycin salve, and adhesive. The bandage, wound covering backing, and adhesive backing print took under 2 min to 3D print. Surgical instrument CAD files were based on commercially available medical-grade stainless-steel instruments. The screw CAD file was downloaded from the NIH 3D Print Exchange website. The prints of the two surgical tools and screw using thermoplastic material were successful. Menisci, relatively complex forms of the cartilage, were 3D bioprinted with a gel that held their form well after printing and were then solidified slightly using a cross-linking solution. After 2 min of solidification, it was possible to remove and handle the menisci.

Conclusion
The current and future challenges of prolonged field care need to be addressed with new techniques, training, and technology. Ruggedized, deployable 3D printers allow for the direct fabrication of medical tools, supplies, and biological solutions for austere use. Delivery of packages can vary, and attention to routes and location is key, especially for transit of time-sensitive perishable supplies such as live cells. The significance of this study provides the real possibility to 3D print “just-in-time” medical solutions tailored to the need of an individual service member in any environment. This is a potentially exciting opportunity to bring critical products to the war front.