title: Nitric oxide-loaded echogenic liposomes for treatment of vasospasm following subarachnoid hemorrhage.
abstract: Delayed cerebral vasospasm following subarachnoid hemorrhage causes severe ischemic neurologic deficits leading to permanent neurologic dysfunction or death. Reduced intravascular and perivascular nitric oxide (NO) availability is a primary pathophysiology of cerebral vasospasm. In this study, we evaluated NO-loaded echogenic liposomes (NO-ELIP) for ultrasound-facilitated NO delivery to produce vasodilation for treatment of vasospasm following subarachnoid hemorrhage. We investigated the vasodilative effects of NO released from NO-ELIP both ex vivo and in vivo. Liposomes containing phospholipids and cholesterol were prepared, and NO was encapsulated. The encapsulation and release of NO from NO-ELIP were determined by the syringe/vacuum method and ultrasound imaging. The ex vivo vasodilative effect of NO-ELIP was investigated using rabbit carotid arteries. Arterial vasodilation was clearly observed with NO-ELIP exposed to Doppler ultrasound whereas there was little vasodilative effect without exposure to Doppler ultrasound in the presence of red blood cells. Penetration of NO into the arterial wall was determined by fluorescent microscopy. The vasodilative effects of intravenously administered NO-ELIP in vivo were determined in a rat subarachnoid hemorrhage model. NO-ELIP with ultrasound activation over the carotid artery demonstrated effective arterial vasodilation in vivo resulting in improved neurologic function. This novel methodology for ultrasound-controlled delivery of NO has the potential for therapeutic treatment of vasospasm following subarachnoid hemorrhage. This ultrasound-controlled release strategy provides a new avenue for targeted bioactive gas and therapeutic delivery for improved stroke treatment.
authors.affiliation: Division of Cardiovascular Medicine, Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, TX, USA.
authors.forename: Hyunggun
authors.initials: H
authors.lastname: Kim
authors.affiliation: Division of Cardiovascular Medicine, Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, TX, USA.
authors.forename: George L
authors.initials: GL
authors.lastname: Britton
authors.affiliation: Division of Cardiovascular Medicine, Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, TX, USA.
authors.forename: Tao
authors.initials: T
authors.lastname: Peng
authors.affiliation: Division of Cardiovascular Diseases, Department of Internal Medicine, and Department of Biomedical Engineering and Radiology, University of Cincinnati, Cincinnati, OH, USA.
authors.forename: Christy K
authors.initials: CK
authors.lastname: Holland
authors.affiliation: Division of Cardiovascular Medicine, Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, TX, USA.
authors.forename: David D
authors.initials: DD
authors.lastname: McPherson
authors.affiliation: Division of Cardiovascular Medicine, Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, TX, USA.
authors.forename: Shao-Ling
authors.initials: SL
authors.lastname: Huang
mesh_terms: D000818:Animals; D004058:Diffusion / Q000528:radiation effects; D018274:Electroporation / Q000379:methods; D045462:Endothelium-Dependent Relaxing Factors / Q000008:administration & dosage / Q000737:chemistry; D019220:High-Energy Shock Waves; D008081:Liposomes / Q000138:chemical synthesis* / Q000528:radiation effects; D053769:Nanocapsules / Q000737:chemistry* / Q000528:radiation effects*; D009569:Nitric Oxide / Q000008:administration & dosage* / Q000737:chemistry; D011817:Rabbits; D013010:Sonication / Q000379:methods*; D013345:Subarachnoid Hemorrhage / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy*; D016896:Treatment Outcome; D020301:Vasospasm, Intracranial / Q000175:diagnosis / Q000188:drug therapy* / Q000209:etiology
chemical_list: D045462:Endothelium-Dependent Relaxing Factors; D008081:Liposomes; D053769:Nanocapsules; D009569:Nitric Oxide
keywords: liposomes; nitric oxide; subarachnoid hemorrhage; ultrasound; vasodilation; vasospasm