Materials

PLGA (weight: 10,500; lactide/glycolide ratio, 75/25) was purchased from Yuanbohuike Institute of Biotechnology (Beijing, China). Lidocaine was purchased from Sarn Chemical Technology Co., Ltd. (Shanghai, China). Polyvinyl alcohol (PVA) was purchased from Shanghai Aladdin Biochemical Co., Ltd. (Shanghai, China). Dichloromethane was purchased from Concord Technology Co., Ltd. (Tianjin, China). The specification of the dialysis membrane purchased from Solarbio Technology Co., Ltd. (Beijing, China). Rapid membrane emulsification equipment (FMEM-500M) and Shirasu Porous Glass (SPG) membrane were purchased from National Engineering Research Center for Biotechnology. The SPG membranes were annulus cylinders with pore sizes of 7.0 μm. A hand-held ultrasound (Model TT-CC-X convex array) apparatus was purchased from Shenyang Tiantai Telemedicine Technology Development Co., Ltd. (Shenyang, China). A cell-crushing apparatus was purchased from Shanghai Xinzhi Biotechnology Research Institute (Shanghai China). An ultrasonic water bath apparatus was purchased from Kunshan Ultrasonic Instruments Co., Ltd. (Kunshan China). A high-speed centrifuge was purchased from Anhui Jiawen Instrument Equipment Co., Ltd. (Anhui China).