Gelfoam

Normal human ectocervical and colorectal tissues were used. Polarized explant cultures were set-up as previously described [29] (link), [30] (link). Briefly, the explant was placed with the luminal side up in a transwell. The edges around the explant were sealed with Matrigel™ (BD Biosciences, San Jose, CA). The explants were maintained with the luminal surface at the air-liquid interface. The lamina propria was immersed in medium for ectocervical explants or resting on medium-soaked gelfoam for colorectal explants. Cultures were maintained at 37°C in a 5% CO₂ atmosphere.
The explants were prepared on day of surgery in duplicate. To ensure even spread of the gels and to allow it to be mixed with HIV-1 for the efficacy testing (below), a 1∶5 dilution of tenofovir or vehicle control gels was applied to the apical side of the explants for 18 h. As controls, explants were untreated or a 1∶5 dilution of 3% N9 gel was applied apically. The next day, explants were washed and viability was evaluated using the MTT [1-(4,5-dimethylthiazol-2-yl)-3,5-diphenylformazan] assay and histology [29] (link), [30] (link).

After allowing the animal to recover at least 1 week from the headplate surgery a craniotomy procedure was performed to either allow for acute implantation of an electrode or to install a glass coverslip for chronic imaging.
Animals were anesthetized using isoflurane (3% induction; 1.5–2% maintenance) in 100% O₂ (0.8–1.0 l/min) and positioned in the stereotaxic frame affixed by the headplate attached previously. The animals were given subcutaneous injections of the analgesic Ketoprofen (5 mg/kg) and 0.2 ml saline to prevent postoperative dehydration. Body temperature was maintained at 37.5°C by a feedback-controlled heating pad; temperature and breathing were monitored throughout surgery. Sterilized instruments and aseptic technique were used throughout. Sterile ocular lubricant (Puralube) was applied at the beginning of each surgical procedure.
For imaging experiments, a 4–5 mm craniotomy was cut out centered at +0.5 mm from lambda and +2.75 mm from midline on the right hemisphere. Care was taken to minimize bleeding, and any bleeds in the skull during drilling were covered with wet gelfoam (Pfizer) until they resolved. After careful removal of the bone flap, a durotomy was performed and the exposed brain was covered in a 1:1 mix of artificial dura (Dow Corning 3-4680). A sterile 4–5 mm coverslip was then pressed into the opening and sealed in place using a combination of cyanoacrylate-based glues. The remaining parts of exposed skull in the headplate well were then covered with black dental acrylic for light blocking purposes and to prevent infection.
For electrophysiology experiments, retinotopic mapping was performed prior to performing any craniotomy, resulting a vasculature and field sign map to identify vasculature landmarks corresponding to either V1, LM, or RL. Once such landmarks had been identified, a small (<1 mm) craniotomy was performed on the morning of each experiment. The craniotomy was sealed with KwikSil (WPI) and animals were allowed to recover for at least 3 hr before subsequent recording experiments.

All PAE were performed using a therapeutic angiographic unit with a digital flat-panel detector system (Allura Xper FD20; Phillips Healthcare, Best, The Netherlands) equipped with cone beam CT option. First, the right common femoral artery (CFA) was punctured in seldinger technique and 5F-sheath was inserted. Probing of left internal iliac artery was conducted using a 5F-RIM, 5F-SIM-1, and a hydrophilic guidewire. Next, DSA in an angulated series (LAO 30°, CRAN 10°) or CBCT (using 3D road map) was performed to identify the origin of the left prostatic artery (PA). Afterwards, a microcatheter (Direxion, Bern-Shape, 2.7/2.4 Fr; Boston Scientific; Marlborough, MA, USA) was coaxially inserted and probing of left the PA was performed using a microwire (Fathom 0.016’’). CBCT was executed applying 5 ml of diluted contrast (Iomeron 400/NaCl; 50:50) at 0.2 ml/s to check embolization position and exclude collateral vessels. If collaterals were observed to penis, bladder or rectum, these branches were occluded temporarily using Gelfoam. Microcatheter was placed distally in wedge position. Embolization was conducted using 250 µm-particles (Embozene Microspheres, Varian Medical Systems, Paolo Alto, CA) and subsequent 350-500 µm-Contour-particles (Boston Scientific, Natick, Massachusetts) until full stasis in the vessel was achieved. Embolization was performed subsequently on the right side in the same way. In case of insufficient probing/catheter positioning (e.g., due to vessel stenosis) or if protective embolization of collateral vessels was unfeasible on one or both sides, prostate embolization was not conducted, respectively. After completing embolization all extraneous material was eliminated, and the puncture side was closed using 6F Angioseal.