Neuronal uptake of nanoformulated superoxide dismutase and attenuation of angiotensin II-dependent hypertension after central administration

Excessive production of superoxide (O2•−) in the central nervous system has been widely implicated in the pathogenesis of cardiovascular diseases, including chronic heart failure and hypertension. In an attempt to overcome the failed therapeutic impact of currently available antioxidants in cardiovascular disease, we developed a nanomedicine-based delivery system for the O2•− scavenging enzyme, copper/zinc superoxide dismutase (CuZnSOD), in which CuZnSOD protein is electrostatically bound to poly-L-lysine (PLL50)-polyethylene glycol (PEG) block co-polymer to form CuZnSOD nanozyme. Different formulations of CuZnSOD nanozyme are covalently stabilized by either reducible or non-reducible crosslinked bonds between the PLL50-PEG polymers. Herein, we tested the hypothesis that PLL50-PEG CuZnSOD nanozyme delivers active CuZnSOD protein to neurons and decreases blood pressure in a mouse model of AngII-dependent hypertension. As determined by electron paramagnetic resonance (EPR) spectroscopy, nanozymes retain full SOD enzymatic activity as compared to native CuZnSOD protein. Non-reducible CuZnSOD nanozyme delivers active CuZnSOD protein to central neurons in culture (CATH.a neurons) without inducing significant neuronal toxicity. In vivo studies conducted in adult male C57BL/6 mice demonstrate that hypertension established by chronic subcutaneous infusion of AngII is significantly attenuated for up to 7 days following a single intracerebroventricular (ICV) injection of non-reducible nanozyme. These data indicate the efficacy of non-reducible PLL50-PEG CuZnSOD nanozyme in counteracting excessive O2•− and decreasing blood pressure in AngII-dependent hypertensive mice following central administration. Additionally, this study supports the further development of PLL50-PEG CuZnSOD nanozyme as an antioxidant-based therapeutic option for hypertension

Effect of Primary Prophylactic Antiseizure Medication for Seizure Prevention Following Intracerebral Hemorrhage in the ERICH Study

Intracerebral hemorrhage (ICH) has the highest morbidity and mortality rate of any stroke subtype and clinicians often administer prophylactic antiseizure medications (ASMs) as a means of preventing post-stroke seizures, particularly following lobar ICH. However, evidence for ASM efficacy in preventing seizures and reducing disability is lacking given limited randomized trials. Herein, we report analysis from a large prospective observational study that evaluates the effect of primary prophylactic ASM administration on seizure occurrence and disability following ICH. Primary analysis was performed on 1630 patients with ICH enrolled in the ERICH study. A propensity score for administration of prophylactic ASM was developed and patients were matched by the closest propensity score (difference < 0.1). McNemar's test was used to compare occurrence of in-hospital seizure and disability, defined by modified Rankin Score (mRS) ≥ 3 at 3 months post ICH. Of the 815 matched pairs of patients treated with primary prophylactic ASM, there was no significant difference in seizure occurrence (p = 0.4631) or disability (p = 0.4653). Subset analysis of 280 matched pairs of patients with primary lobar ICH similarly revealed no significant difference in seizure occurrence (p = 0.1011) or disability (p = 1.00) between prophylactically treated and untreated patients. Although current guidelines do not recommend primary prophylactic ASM following ICH, clinical use remains widespread. Data from the ERICH study did not find an association between administering primary prophylactic ASM and preventing seizures or reducing disability following ICH, thus providing evidence to influence clinical practice and patient care

Neuronal uptake of nanoformulated superoxide dismutase and attenuation of angiotensin II-dependent hypertension after central administration

Excessive production of superoxide (O2•−) in the central nervous system has been widely implicated in the pathogenesis of cardiovascular diseases, including chronic heart failure and hypertension. In an attempt to overcome the failed therapeutic impact of currently available antioxidants in cardiovascular disease, we developed a nanomedicine-based delivery system for the O2•− scavenging enzyme, copper/zinc superoxide dismutase (CuZnSOD), in which CuZnSOD protein is electrostatically bound to poly-L-lysine (PLL50)-polyethylene glycol (PEG) block co-polymer to form CuZnSOD nanozyme. Different formulations of CuZnSOD nanozyme are covalently stabilized by either reducible or non-reducible crosslinked bonds between the PLL50-PEG polymers. Herein, we tested the hypothesis that PLL50-PEG CuZnSOD nanozyme delivers active CuZnSOD protein to neurons and decreases blood pressure in a mouse model of AngII-dependent hypertension. As determined by electron paramagnetic resonance (EPR) spectroscopy, nanozymes retain full SOD enzymatic activity as compared to native CuZnSOD protein. Non-reducible CuZnSOD nanozyme delivers active CuZnSOD protein to central neurons in culture (CATH.a neurons) without inducing significant neuronal toxicity. In vivo studies conducted in adult male C57BL/6 mice demonstrate that hypertension established by chronic subcutaneous infusion of AngII is significantly attenuated for up to 7 days following a single intracerebroventricular (ICV) injection of non-reducible nanozyme. These data indicate the efficacy of non-reducible PLL50-PEG CuZnSOD nanozyme in counteracting excessive O2•− and decreasing blood pressure in AngII-dependent hypertensive mice following central administration. Additionally, this study supports the further development of PLL50-PEG CuZnSOD nanozyme as an antioxidant-based therapeutic option for hypertension