Current research activities are focused on Spinal Cord Injury (SCI), Parkinson’s Disease (PD), and Multiple Sclerosis (MS). SCI is a complex debilitating condition leading to life-long neurological deficits as well as bone loss and muscle atrophy due to immobility. Our laboratory was among the first to show that estrogen (E2) drives neuroprotection in experimental SCI in rats, suggesting E2 warrants clinical evaluation in neurotrauma. New smart drug delivery techniques, including nanoparticles, may allow for increased drug safety and improved efficacy. Thus, the goal is to examine the effects of a novel slow release E2-loaded nanoparticle (SNP-E2) gel patch on neuronal dysfunction and skeletal muscle loss in a rat model of SCI. We hypothesize that focal delivery of estrogen via slow release nanoparticles SNP-E2 will maintain low systemic E2 levels (plasma) and higher tissue concentrations, thereby allowing for maximized therapeutic potential for recovery from neural and skeletal muscle loss in SCI. To test the hypothesis, two specific aims are proposed: (Aim 1) Examine the delivery of a novel slow release SNP-E2 and determine its kinetics, bio-distribution, toxicity, and effects in moderate and severe SCI and (Aim 2) Determine the effects of SNP-E2 on alterations of skeletal muscle loss in moderate and severe SCI. Overall, the proposed studies should provide a safe and novel strategy to improve health and functional recovery for Veterans with SCI. Parkinson’s disease (PD) is a progressive degenerative disorder affecting almost 80,000 Veterans. While the mechanisms of this degenerative process remain elusive, chronic inflammation may be involved. Calpain not only plays a pivotal role in brain (SN-DA neurons) and spinal cord (SC) degeneration, it may also drive inflammation and disease progression. Inhibition of calpain attenuates a distinct subpopulation of T cells in MPTP mice, suggesting calpain’s involvement in the inflammatory process. Our goal is to develop therapeutic strategies to treat PD with agents that block the inflammatory process, protect neurons, control disease progression, and improve function. We hypothesize that calpain activation, infiltration of inflammatory T cells (Th1/Th17), and released cytokines and chemokines are involved in progressive degeneration of PD, and calpain inhibitor treatment may reduce degeneration, slow disease progression, and improve function. Two specific aims will test the hypothesis: (Aim 1) Investigate the role of calpain regulation and T cell infiltration in SC degeneration and disease progression in MPTP mice, characterize infiltrating T cells, assess cytokine/chemokine levels in sera, and determine cell death parameters and calpain activation in SC; (Aim 2) Examine whether treatment of MPTP mice with calpain inhibitor will reduce degenerative inflammatory events and improve function. Increased calpain activity has also been found in MS as well as in its animal model [experimental autoimmune disea...