Medpor

Porous polyethylene sheets (PPE; Medpor^®; Stryker, Kalamazoo, MI, USA; formerly Porex Surgical, Newnan, GA; pore size 100–250 μm; thickness 250 μm) were cut into rectangular 3.0 × 3.0 mm squares and steam-sterilized. Prior to implantation, PPE implants were either bathed in sterile 0.9% saline solution or coated according to the respective experimental group. One group was coated with 50 μl growth factor reduced (GFR) BD Matrigel Matrix (Becton Dickinson, Heidelberg, Germany) or GFR BD Matrigel Matrix supplemented with 5 μl Etanercept (Enbrel^® at 25 mg/ml concentration, Wyeth-Ayerst Pharmaceutica Inc., PA, USA). Liquid GFR BD Matrigel entered the scaffold at 37 °C (animal body temperature).

After completion of the cranial operation using the pterional approach, which was performed as described by Spetzler and Lee [21 (link)], the bone flap was secured to the skull with metallic plates and screws (Figure 1). The prefabricated high-density polyethylene (HDPE) implant (Medpor; Stryker, Kalamazoo, MI) was tailored with heavy scissors to fit the dimensions and contours of the defect accurately. Once positioned correctly, the Medpor® implant was secured in place with metallic screws (Figure 2). The temporalis muscle was then suspended and the soft tissue was approximated (Figure 3).