BME Seminar Series: Archie Tram, Caitlin Jones, & Maria Talarico
"A Hydrogel Vitreous Substitute that Releases Antioxidant"
Current experimental vitreous substitutes only replace the physical functions of the natural vitreous humor. Removal of the native vitreous disrupts oxygen homeostasis in the eye, causing oxidative damage to the lens that likely results in cataract formation. Neither current clinical treatments nor other experimental vitreous substitutes consider the problem of oxidative stress after vitrectomy. To address this problem, biomimetic hydrogels are prepared by free radical polymerization of poly(ethylene glycol) methacrylate and poly(ethylene glycol) diacrylate. These hydrogels have similar mechanical and optical properties to the vitreous. The hydrogels are injectable through small‐gauge needles and demonstrate in vitro biocompatibility with human retinal and lens epithelial cells. The hydrogels and added vitamin C, an antioxidant, show a synergistic effect in protecting ocular cells against reactive oxygen species, which fulfills a chemical function of the natural vitreous. These hydrogels have the potential to prevent post‐vitrectomy cataract formation and reduce the cost of additional surgeries.
"Mechanisms of extracellular matrix reorganization in the mammary gland by stromal PTEN"
The extracellular matrix (ECM) becomes aligned throughout breast cancer progression, providing highways for cancer cell invasion and metastasis. Cancer-associated fibroblasts play a large role in ECM remodeling, but the molecular mechanisms behind this matrix alignment remain unclear. Knockout of the tumor suppressor gene phosphatase and tensin homolog (Pten) in fibroblasts increases collagen deposition in the mammary gland and promotes tumor incidence and growth in mice expressing the MMTV-Neu oncogene. Here, we demonstrate that that loss of Pten in fibroblasts increases cell contractility and leads to reorganization of the ECM both in vitro and in vivo. Furthermore, to examine the mechanism behind how Pten loss contributes to ECM alignment, a 384-well fibroblast-derived matrix screening platform was developed to examine the effects of a kinase inhibitor library on matrix alignment by Pten-/- fibroblasts. Automated confocal microscopy and a custom MATLAB script were used to image and analyze the matrices to identify downstream effectors of matrix alignment.
"Characterizing Biomechanical Movement Patterns and Marksmanship Performance of Tactical Athletes During ‘Shoot on the Move’"
Physical augmentation devices and exoskeletons for tactical athletes, such as Soldiers, military Special Operators, law enforcement Special Weapons and Tactics (SWAT) or Special Response Team (SRT) operators, are potentially beneficial tools to increase survivability and assist with load carriage. Current control systems for such devices and exoskeletons are largely designed using information from basic movements, such as walking. Although tactical athletes perform basic movements during operations, little consideration has been given to factors, such as load carriage and moving while maintaining weapon aim, that are critical to operational success and survivability but may also influence capabilities during a mission. To address this current limitation, lower extremity kinematics and spatiotemporal characteristics of normal walking and walking while maintaining weapon aim (i.e. ‘shoot on the move’) were identified while donning body-borne load and moving at different speeds. Marksmanship performance was also collected during ‘shoot on the move’ to identify potential factors that influence overall performance, such as marksmanship during static position. Findings suggest that biomechanical movement patterns are not the same between normal walking and ‘shoot on the move’; these differences are observed to a greater degree with increasing movement speed and body-borne load. Findings also suggest that marksmanship performance during static firing position is a significant estimator of marksmanship performance during ‘shoot on the move’ at short distance. A better understanding of operationally-relevant movement biomechanics and dynamic marksmanship performance will provide appropriate and comprehensive information for the design of physical augmentation devices as well as guide movement optimization for the occupational demands of tactical athletes.