On-Demand Prolongation of Peripheral Nerve Blockade through Bupivacaine-Loaded Hydrogels with Suitable Residence Periods. Ning, Cong; Ying Guo; Lesan Yan; Jayesh P. Thawani; Wenjing Zhang; Changfeng Fu; Tiecheng Liu and Jianxun Ding. ACS Biomaterials Science & Engineering, 2019. 5(2), 696-709.