Monocryl

Anesthesia and surgery were performed as described previously^{12 (link)}. In brief, after preoperative analgesia (buprenorphine 0.03 mg/kg, s.c. and carprofen 5 mg/kg, s.c.), the rat was anesthetized with isoflurane and the right tibia aseptically prepared. A 1 cm incision was made on the proximolateral aspect of the right tibia. A ø1.2 mm unicortical hole was drilled 2 mm distal to the growth plate, then tapped (2 mm outer ø/1.2 mm inner). After the sterile or colonized screw was inserted manually, the fascia and skin were closed in two layers using absorbable suture material (Monocryl and Vicryl rapid, Ethicon Inc., Cincinnati, USA; sizes 6–0 and 5–0, respectively). For postoperative analgesia, buprenorphine (0.05 mg/kg, s.c.) was administered every 12 h for 3 days and paracetamol (7 ml Dafalgan syrup/100 ml water; Bristol-Myers Squibb) was given via drinking water for a period of 7 days.

In all experimental animals, the right median nerve was transected via micro scissor in the medial third of the upper arm, 5 mm proximal to its entrance in the cubital fossa. The nerve was immediately reconstructed using three epineural nerve sutures (10-0, non-absorbable, monofilament suture, Ethilon, Ethicon Germany by Johnson & Johnson Medical GmbH, Norderstedt, Germany). The wound was closed via subcutaneous and transcutaneous sutures (4-0 monofilament, absorbable suture, Monocryl, Ethicon Germany by Johnson & Johnson Medical GmbH, Norderstedt, Germany). A volatile oxygen-anesthetics mixture (95% oxygen and 5% Isoflurane) provided sufficient anesthesia and subcutaneous buprenorphine injections (0.05 mg/kg bodyweight) ensured adequate peri- and postoperative analgesia. For the post-surgical ultrasound therapy, the FDA-approved EXOGEN bone-healing device (Bioventus LLC, Durham, USA) was applied directly on the shaved skin above the nerve suture site, using standard coupling gel and with the following transducer output parameters: application time 2 min, frequency 1.5 ± 5% MHz, intensity 30 ± 30% mW/cm² (SATA), repetition rate: 1.0 ± 10% kHz, Duty cycle: 20%. A short-term Isoflurane anesthesia prevented limb motion-induced ultrasound transmission artifacts.

The sockets of the treatment side were completely filled with MGH (L-Mesitran Soft; Triticum Exploitatie), which was applied by syringe or spatula (Figures 1 and 2). Afterwards, the sockets were closed by suturing the mucoperiosteal flap over the defect in the gingiva with single interrupted sutures, applying four throws in each knot, using poliglecaprone 5/0 on a taper point needle (Monocryl; Ethicon). An example of this procedure is presented in Figure 3. On the control side, a blood clot was allowed to form in the socket after flushing, and the mucoperiosteal flap was then sutured as described for the treatment side.

Polycaprolactone (PCL) with inherent viscosity between 1.0 and 1.3 dL/g in CHCl₃ was obtained from LACTEL Absorbable Polymers (Birmingham, AL). Poliglecaprone (PGC) was acquired in the form of absorbable surgical sutures under the trade name of Monocryl^® (Ethicon). The solvent 1,1,1,3,3,3-hexafluoro-2-propanol (HFP) was purchased from Sigma-Aldrich (St. Louis, MO) to dissolve PCL and PGC (weight ratio PCL:PGC = 3:1) and make a homogeneous solution. Lipase (Pseudomonas fluorescens) was purchased from Sigma-Aldrich. The protein matrix (HB) was provided by Vivo Biosciences Inc. (Birmingham, AL). HUVECs and AoSMCs (Lonza Group Ltd) were kindly provided by Dr. Jun’s Laboratory at passage 3. The HUVECs were cultured into the endothelial cell growth media (EGM-2 Lonza Group Ltd) at 37 °C under 5 % CO₂. The AoSMCs were cultured into the smooth muscle cells growth media (SMGM-2 Lonza Group Ltd) at 37 °C under 5 % CO₂.