Ethilon

In order to shield the 8 mm long electrospun tubular PCL2000-U4U scaffold, an end-to-end anastomosis was made to a 4 mm long low-porosity ePTFE tube (Zeus Industrial Products Inc., Orangeburg, SC, USA) using interrupted 8-0 nylon sutures (Ethilon^®; Ethicon, Johnson & Johnson, New Brunswick, NJ, USA) proximally and distally from the electrospun scaffold. In addition, a low-porosity ePTFE tube was mounted on the outer surface of the shielded electrospun tubular scaffold and tightened at both shielded sides using a single 6-0 suture ligature (Prolene^®; Ethicon, Johnson & Johnson, New Brunswick, NJ, USA) (Figure 1B,D). The thickness of the ePTFE tube was 350 micrometer. All of the scaffolds were sterilized by Ethylene Oxide sterilization (Synergy Health, Venlo, The Netherlands) prior to implantation.

A fresh sample of the melanoma of the patient was obtained and transported immediately to the laboratory at AntiCancer, Inc., on wet ice. The sample was cut into 5-mm fragments and implanted subcutaneously in nude mice. After three weeks, the subcutaneously-implanted tumors grew to more than 10 mm in diameter. The subcutaneously-grown tumors were then harvested and cut into small fragments (3 mm³). After nude mice were anesthetized with the ketamine solution described above, a 5-mm skin incision was made on the right chest into the chest wall, which was split to make space for the melanoma tissue fragment. A single tumor fragment was implanted orthotopically into the space to establish the PDOX model. The wound was closed with a 6–0 nylon suture (Ethilon, Ethicon, Inc., NJ, USA) [45 (link)].

Our laboratory pioneered the PDOX nude mouse model with the technique of surgical orthotopic implantation (SOI), including pancreatic [22 (link)–25 (link)], breast [26 (link)], ovarian [27 (link)], lung [28 (link)], cervical [29 (link)], colon [30 (link)–32 (link)], stomach [33 (link)], sarcoma [34 (link)–38 (link)], and melanoma [39 (link)–41 (link)].
The PRMS tumor was previously established at AntiCancer, Inc. [10 (link)]. Tumors were initially grown subcutaneously after transplantation of 5 mm fragments. After 3 weeks growth, tumors were harvested and cut into small fragments (3-4 mm). After nude mice were anesthetized, a 5 mm skin incision was made on the right high thigh, then the biceps femoris or quadriceps was split to make space for the tumor. A single tumor fragment was implanted orthotopically into the space to establish a PDOX model [10 (link)]. The wound was closed with 6-0 nylon suture (Ethilon, Ethicon, Inc., NJ, USA).

Cerebral ischemic injury was induced by the model of middle cerebral artery occlusion as described by Longa et al.38 (link). Briefly, the mice were anesthetized by 4% chloral hydrate (0.01 ml/g body weight) via intraperitoneal (i.p.) injection. The right common carotid artery (CCA), the right external carotid artery (ECA) and the internal carotid artery (ICA) were exposed through a ventral midline neck incision. After the CCA was clamped and the ECA was ligatured by silk sutures, the ECA was cut 2 mm distal to the ECA–CCA branch. A 6–0 nylon monofilament (Ethilon, Ethicon Inc) coated with silicon resin (Heraeus, Kulzer, Germany) was inserted intraluminally into the right CCA 9–11 mm distal to the origin of middle cerebral artery until a faint resistance was detected. Reperfusion was achieved by withdrawing the suture after MCAO at indicated time (50, 60 or 70 min) to restore blood supply of the MCA territory. Body temperature was maintained at 36.5–37.5 °C using a heating pad on the surgical table throughout the procedure from the start of the surgery until the animals revived from anesthesia. To monitor ischemia and reperfusion, the local cerebral blood flow was measured using a Laser-Doppler blood flowmeter (Periflux 5010, PERIMED, Sweden) positioned at 1 mm posterior and 3 mm lateral to the Bregma.