Optimized Healing Thanks to Virtual Wounds

By Merry Morris

Originally used in video games, computer modeling is increasingly being used to investigate and predict complicated real-life events. Agent-based modeling (ABM) simulates the ways many individual agents, e.g., virtual soldiers, will interact based on the rules set by the programmers. Myriad scenarios can be set, tested and altered to see how the outcome changes.

Complex events occur within the human body, such as when the body fights off an infection or repairs cell damage. This inflammatory process is critical for survival — without it the body cannot repair itself. Researchers like Gary An, surgeon and researcher at the University of Chicago in Illinois, and Shayn Peirce, researcher at the University of Virginia in Charlottesville, are using ABM to create “virtual wounds” with immune cells as programmable “agents.” Their models are robust enough to closely simulate the body’s actual inflammation response.

Inflammation Response – Friend and Foe

When a wound is created by falling, cutting, scraping or other damage, the body’s protective and healing functions kick into high gear.

• More blood flows to the injured area as blood vessels dilate
• Fluid and blood proteins flood into spaces around the damaged cells as capillaries become more permeable
• Fighting forces, the white blood cells called neutrophils, move into the area and release enzymes that attack invading microorganisms
• Debris-cleaning macrophages arrive to clean up the battlefield, allowing the neutrophils to go off duty

Sometimes, however, the “field instructions” get fouled up — no one tells the neutrophils to go home — and they continue fighting, attacking the wrong targets in a cellular level “friendly fire.” Sepsis is the result, as the battle spreads immune chemicals throughout the entire body in life-threatening, out-of-control inflammation. This is not a minor problem: severe sepsis is a leading cause of death in the United States with its incidence estimated to be 300 cases per 100,000 population.

Not Just for Games Anymore

Now, with ABM becoming a potent study tool, researchers can use its simulation power to better understand the intricate interactions of inflammation and sepsis. With ABM, possible remedies can be tested in the virtual sepsis patient where a failure is not tragic, and work toward finding the most effective treatment.