RT Journal Article
SR Electronic
T1 Ropivacaine-loaded, hydroxypropyl chitin thermo-sensitive hydrogel combined with hyaluronan: an injectable, sustained-release system for providing long-lasting local anesthesia in rats
JF Regional Anesthesia & Pain Medicine
JO Reg Anesth Pain Med
FD BMJ Publishing Group Ltd
SP 234
OP 241
DO 10.1136/rapm-2021-102726
VO 47
IS 4
A1 Qiao, Qianqian
A1 Fu, Xiangyun
A1 Huang, Rui
A1 Lei, Shaoqing
A1 Leng, Yan
A1 Liu, Zhigang
A1 Xia, Zhongyuan
A1 Jiang, Xulin
YR 2022
UL http://rapm.bmj.com/content/47/4/234.abstract
AB Background and objective Ropivacaine hydrochloride is a commonly used local anesthetic in clinics. However, local injection or continuous infusion of ropivacaine has been associated with several disadvantages. Accordingly, it is important to develop a new controlled release system for local administration of ropivacaine to achieve a prolong anesthetic effect, improve efficacy, and minimize the side effects.Methods We developed injectable hydroxypropyl chitin thermo-sensitive hydrogel (HPCH) combined with hyaluronan (HA), which was used to synthesize a ropivacaine (R)-loaded controlled release system. We then conducted drug release test and cytotoxicity assay in vitro. Importantly, we examined the analgesic effects and biocompatibility of this system in vivo by injecting different concentrations of R-HPCH-HA (7.5, 15, 22.5 mg/mL), ropivacaine hydrochloride (RHCL, 7.5 mg/mL), or saline (all in 0.5 mL) near the sciatic nerve in rats.Results R-HPCH-HA induced concentration-dependent thermal-sensory blockade and motor blockade in vivo. In hot plate test, R-HPCH-HA (22.5 mg/mL) induced a significant longer thermal-sensory blockade (17.7±0.7 hours), as compared with RHCL (7.5 mg/mL, 5.7±0.8 hours, n=6/group, p<0.05). It also produced a more prolonged motor blockade (6.8±0.8 hours) than RHCL (3.5±0.8 hours, p<0.05). R-HPCH-HA caused less cytotoxicity than RHCL, as indicated by the higher cell viability in vitro (n=8/group).Conclusion Our findings in a sciatic nerve block model demonstrated that the injectable, ropivacaine-loaded controlled release system effectively prolonged the local analgesic effect in rats without notable side effects.Data are available upon reasonable request. All data included in this study are available upon request by contact with the corresponding author.