Vicryl 2

A midline incision was made through the skin from the right and left orbits to the occipital part of the calvaria. The temporalis muscles were subperiosteally elevated from the frontal bone and retracted bilaterally (flap). All remaining soft tissue attached to the bone was sharply dissected to expose the site and prepare the frontal bone for implantation. Two semi‐onlay implants were bilaterally placed on the frontal bone of the skull of each sheep. Each implant was fixed to the frontal bone with two self‐drilling 1.5 × 4 mm bone screws (Medicon, art no: 68.93.24 A) one in each opposite fixation points of the implant, as outlined in Figure 1a, D‐E. Following fixation of the implants, the soft tissues were closed with absorbable sutures (Vicryl^® 2‐0, Ethicon) and the skin was closed with non‐absorbable sutures (Prolene^® 2‐0, Ethicon) and surgical staples. The wounds were disinfected using oxytetracycline (Oxytetrin^® spray, MSD).

Induction of liver injury was performed based on the surgical procedure described by Awad and colleagues [23 (link)], with minor modifications [24 (link)]. Briefly, on day 0, laparotomy was performed and the bile ducts and portal vein in the hepatoduodenal ligament were exposed in order to ligate the cystic, common hepatic, and the common bile duct (Vicryl^® 2/0, Ethicon Inc., Norderstedt, Germany). The latter was ligated twice to ensure complete obstruction of bile flow. Afterwards, the portal vein and inferior (caudal) vena cava were partially clamped before a functional end-to-side portosystemic anastomosis was established. Arterial supply of the liver was not interrupted, and the development of splanchnic congestion was avoided by ensuring an adequate portal flow during partial clamping [24 (link)]. Cefuroxime (i.v. 500 mg) was infused during surgery. The animals were returned to their pens where they were clinically observed.

The magnesium scaffolds were made from the magnesium alloy LA63, containing 6 wt% (weight percent) of lithium and 3 wt% aluminum. Extruded sheets of this alloy were cut with a thickness of 0.5 mm using abrasive waterjet technology to form a circular segmented structure. Garnet mesh #120 was used as the abrasive. The abrasive water jet cutting technique has already been described in detail elsewhere [8 ,9 (link)]. The structure’s design was previously calculated using finite element simulation [10 (link)]. The segmented support structures consisted of a central, oval ring (see Figure 1A), around which eight wing segments were placed in a circle (see Figure 1B). The central ring contained eight boreholes through which the wing segments were to be fixed pre-operatively immediately after sterilization with surgical sutures. At the central ring, the wing segments were secured with a nonabsorbable suture (Polyprolene 2.0, Ethicon, Germany). The wing segments were affixed to each other with an absorbable, braided suture (Vicryl 2.0, Ethicon, Germany) (see Figure 1).