Site-specific analgesia with sustained release liposomes

摘要

Prevention or relief of localized pain is a challenging problem. The conventional local anesthetic agents used clinically are characterized by limited duration of analgesia and may result in both systemic and local toxicity (1). Thus, an unmet need for longer acting and safer pain control therapeutics exists. In a search for compounds providing prolonged anesthesia without myo- and neurotoxic effects, a class of nonterpene alkaloids represented by saxitoxin (STX) have evolved as promising candidates (2). A highly potent blocker of nerve conduction, STX was identified early last century as the cause of paralytic shellfish poisoning (3). Further investigations of its mode of action led to the discovery of its primary target, the voltage-gated sodium channel (4). Since then STX, as a member of the "site 1 sodium channel blocker" family of compounds, has become an invaluable tool in biomedical research.