BME Seminar Series: YongChen Wang & Albert Chen

YongChen Wang:

"ZnO Nanorod Array as an Inhibitory Biointerface"

One-dimensional zinc oxide (ZnO) nanostructure arrays show unique semiconducting, piezoelectric, wetting, and fluorescent properties, and how they interact with cells is critical for their biomedical applications. We prepared densely-packed and vertically-aligned ZnO nanorod arrays (ZnO NRAs) and studied their interactions with cells either as a substrate or patch. We find that ZnO NRAs as a substrate can inhibit cell adhesion and spreading, and with the inhibited adhesion and spreading, primary cells remain viable while cell lines are dead. We also find that ZnO NRAs as a patch can selectively kill underneath cells. We further identify surface nanomorphology as the dominant factor responsible for the inhibitory effect. These discoveries suggest potential application of ZnO NRAs as a cell inhibitory biointerface.

Albert Chen:

"Single-leg hop mechanics are significantly correlated with patient-reported outcomes after anterior cruciate ligament reconstruction"

Anterior cruciate ligament (ACL) injuries are one of the most common orthopedic injuries. Not only are these injuries associated with a large economic burden, but they can lead to loss of participation in athletics for up to a year or more. While ACL reconstruction (ACLR) can restore passive laxity of the knee joint to acceptable levels, long term sequelae still exist with this injury. Altered movement mechanics can be present up to two years after injury and the risk for a second ACL injury is six times greater than that of a non-injured athlete. In addition, early onset osteoarthritis (OA) is extremely common in this population, which can lead to lower activities levels and decreased quality of life. It has been proposed that the altered knee mechanics present after ACLR is one of the main driving factors that lead to early onset OA. The Knee Injury and Osteoarthritis Outcomes Score (KOOS) is a patient-reported outcome that can determine whether a patient is beginning to show symptoms of knee OA after ACLR without having to rely on radiographs or other expensive imaging techniques. Previous studies have shown that a correlation exists between gait biomechanics after ACLR and KOOS, but there has been little work done to show how single-leg hop performance relates to patient-reported function. This talk will focus on the correlation between KOOS scores and hip and knee mechanics after ACLR during a single-leg hop task. This task was chosen as it is frequently used in clinical settings to determine readiness to return to sport, and mimics cutting tasks common in many sports. Significant correlations were found between KOOS and hip and knee mechanics during the single-leg hop. These results indicate a relationship between hop mechanics and patient reported function, which can be valuable in tracking a patient’s recovery in a fairly quick and non-invasive manner.