BACKGROUND: Prolonged nerve blockade is potentially useful in the management of many acute and chronic pain problems. Aside from infusions via an indwelling catheter, most currently available nondestructive techniques for prolonging local anesthetic action cannot provide more than 1-2 days of blockade. Bioerodible polymer matrixes have been used to deliver a variety of drugs in patients and animals for periods lasting weeks to years. Previously, dibucaine and bupivacaine were incorporated into copolymers of 1,3 bis(p-carboxyphenoxy) propane-sebacic acid anhydride (1:4), and demonstrated sustained release in vitro following incubation of the drug-polymer matrixes in phosphate-buffered solution (pH 7.4, 37 degrees C). METHODS: In the present study, cylindrical pellets made from polymer matrixes incorporated with bupivacaine-HCl were implanted surgically along the sciatic nerves of rats. Neural block was assessed by direct observation of motor skills and by leg-withdrawal latency to a hot surface. Biochemical and histologic examinations were performed 2 weeks after implantation. RESULTS: Sensory and motor blockade was produced for periods ranging from 2 to 6 days. Contralateral control legs receiving polymer implants without drug showed no block. Blockade was reversible, and animals appeared to recover sensory and motor function normally. Biochemical indexes of nerve and muscle function were indistinguishable from contralateral controls. CONCLUSIONS: This biodegradable polymer system provides a promising new alternative for the delivery of local anesthetics to peripheral nerves to produce prolonged blockade for the management of acute and chronic pain.
BACKGROUND: Prolonged nerve blockade is potentially useful in the management of many acute and chronic pain problems. Aside from infusions via an indwelling catheter, most currently available nondestructive techniques for prolonging local anesthetic action cannot provide more than 1-2 days of blockade. Bioerodible polymer matrixes have been used to deliver a variety of drugs in patients and animals for periods lasting weeks to years. Previously, dibucaine and bupivacaine were incorporated into copolymers of 1,3 bis(p-carboxyphenoxy) propane-sebacic acid anhydride (1:4), and demonstrated sustained release in vitro following incubation of the drug-polymer matrixes in phosphate-buffered solution (pH 7.4, 37 degrees C). METHODS: In the present study, cylindrical pellets made from polymer matrixes incorporated with bupivacaine-HCl were implanted surgically along the sciatic nerves of rats. Neural block was assessed by direct observation of motor skills and by leg-withdrawal latency to a hot surface. Biochemical and histologic examinations were performed 2 weeks after implantation. RESULTS: Sensory and motor blockade was produced for periods ranging from 2 to 6 days. Contralateral control legs receiving polymer implants without drug showed no block. Blockade was reversible, and animals appeared to recover sensory and motor function normally. Biochemical indexes of nerve and muscle function were indistinguishable from contralateral controls. CONCLUSIONS: This biodegradable polymer system provides a promising new alternative for the delivery of local anesthetics to peripheral nerves to produce prolonged blockade for the management of acute and chronic pain.
Authors: Andrew Li; Akishige Hokugo; Anisa Yalom; Eric J Berns; Nicholas Stephanopoulos; Mark T McClendon; Luis A Segovia; Igor Spigelman; Samuel I Stupp; Reza Jarrahy Journal: Biomaterials Date: 2014-07-23 Impact factor: 12.479
Authors: J Brian McAlvin; Robert F Padera; Sahadev A Shankarappa; Gally Reznor; Albert H Kwon; Homer H Chiang; Jason Yang; Daniel S Kohane Journal: Biomaterials Date: 2014-03-06 Impact factor: 12.479
Authors: Sandra Amado; Jorge M Rodrigues; Ana L Luís; Paulo A S Armada-da-Silva; Márcia Vieira; Andrea Gartner; Maria J Simões; António P Veloso; Michele Fornaro; Stefania Raimondo; Artur S P Varejão; Stefano Geuna; Ana C Maurício Journal: J Neuroeng Rehabil Date: 2010-02-11 Impact factor: 4.262