Cd1 foxn1 nude mice

TES-4 samples were grafted onto the backs of CD1-Foxn1 nude mice (Charles River Laboratories, Wilmington, NC, USA), as previously described [32 (link),33 (link)]. Briefly, a portion of the mid-back skin of the mouse was removed. Then, the fascicular panniculus was removed with forceps to expose muscle, and a custom-made silicone Fusenig’s chamber was inserted around the wound to prevent contraction of the mouse skin. The Fusenig’s chamber was secured in place by four intramuscular sutures (Prolene 4-0, Ethicon, Raritan, NJ, USA). A 5 cm² biopsy was taken from the skin substitutes cultured for 10 days at the air–liquid interface, mounted on a non-adhering dressing (AdapticTM, Acelity, San Antonio, TX, USA), and grafted into the aperture. To prevent graft displacement, sterile gauzes were placed over the substitute inside the Fusenig’s chamber and served as a bolus tie-over pressure dressing. The gauzes were taken out after 7 days. The silicone chambers were removed 21 days after grafting. Three to four mice per condition at each time point were euthanized 3 weeks, 3 months, and 6 months after grafting for tissue collection and analysis.

All animal experiments were performed in accordance with the guidelines of Swiss federal law on animal protection. CD1 Foxn1 nude mice were purchased from Charles River Laboratories (Wilmington, MA, USA). Eleven 6-10-week-old mice per group were used in all experiments. Mice were anaesthetized using an intraperitoneal 3 component injection consisting of fentanyl, midazolam and medetomidin, fixed under a stereotactic device (Stoelting, Wood Dale, IL, USA) and a burr hole was drilled in the skull 2 mm lateral and 1 mm posterior to the bregma. A Hamilton syringe needle was introduced to a depth of 3 mm and LN-229 human glioma cells (75,000) in a volume of 2 µl phosphate-buffered saline (PBS) were injected into the right striatum. Local cranial radiotherapy with a single dose of 12 Gy was performed at day 15 after tumor implantation using a Gulmay 200 kV X-ray unit at 1 Gy/min at room temperature. The mice were observed daily and euthanized when neurological symptoms developed. No blinding was done for mouse experiments.