Comparative study of rheological properties and preclinical data of porous polycaprolactone microsphere dermal fillers.

BACKGROUND: In this study, a physical properties test and preclinical evaluation were performed on two polycaprolactone (PCL)-based dermal filler formulas. OBJECTIVE: This study was performed to compare the rheological characteristics, preclinical efficacy, and safety of a new PCL filler, SF-01, with a licensed PCL filler. METHODS: First, the viscoelasticity of the PCL filler was evaluated. Next, hairless mice were injected with fillers and evaluated for efficacy with a folliscope and PRIMOSLITE . Histological evaluation was conducted for 6 months to evaluate safety. RESULTS: In this evaluation, SF-01 was superior to a licensed PCL filler in initial volume increase rate and in vivo durability, and the migration of the injected filler was not confirmed. The elasticity (G*, G') and viscosity (G'') are also expected to be lower than those of a licensed PCL filler, thereby resulting in less foreign body sensation in the living body. CONCLUSION: SF-01 (porous PCL microsphere-based dermal filler) has been confirmed to be superior in durability and shape retention compared to the licensed PCL filler (nonporous PCL microsphere-based dermal filler), and the in vivo safety is equivalent.

In Vivo Comparison of MONOFIX, A Novel Barbed Suture with a Triangular Stopper, with Pre-existing Products in a Porcine Model.

STUDY OBJECTIVE: MONOFIX, a new absorbable barbed suture device, has a triangular stopper at the end to hold the suture to the tissue without hooking the looped end or knotting. The aim of this study was to compare the biomechanical strength and histologic features of MONOFIX with other barbed suture devices using a porcine model. DESIGN: Well-designed, controlled trial without randomization. SETTING: Animal laboratory in university hospital. SUBJECTS: Sixteen, 60-kg, mature female domestic pigs (skin closure group) and 5, 60-kg, mature female domestic pigs (fascial closure group). INTERVENTIONS: In the skin closure group, 3-0 MONOFIX versus 2 widely used 3-0 absorbable barbed sutures (3-0 V-Loc 180 or Stratafix). In the fascial closure group, 2-0 MONOFIX versus 1 widely used 2-0 absorbable barbed sutures (2-0 Stratafix). MEASUREMENTS AND MAIN RESULTS: In the skin closure group, the biomechanical wound strength of skin sutured with size 3-0 MONOFIX, V-Loc 180, or Stratafix was evaluated by postoperative day assessment (days 0, 3, 7, 14, and 28). In the fascial closure group, pigs underwent 2 paramedian incisions and were sutured with 2-0 MONOFIX or with 2-0 Stratafix to evaluate histologic reaction. At 6 weeks the tissues around the suture line were excised and microscopically evaluated. The biomechanical strength of the MONOFIX had similar tissue tensile strength compared with the control, regardless of postoperative day. In the fascial closure model, there was no significant difference in the average tissue reaction score between MONOFIX and Stratafix (1.2 ± .3 vs 1.3 ± .3, p = .478). CONCLUSION: This study demonstrated that MONOFIX has equivalent tensile strength and histologic reaction when compared with commonly used barbed suture devices. Accordingly, this preclinical study suggests that the use of MONOFIX is a safe alternative to other barbed suture devices.

Efficacy of Oxidized Regenerated Cellulose, SurgiGuard®, in Porcine Surgery.

PURPOSE: Adequate hemostasis is important for postoperative outcomes of abdominal surgery. This study evaluated the hemostatic effects and accompanying histopathological changes of a novel oxidized regenerated cellulose, SurgiGuard®, during abdominal surgery. MATERIALS AND METHODS: Ten pigs underwent wedge resection of the spleen (1×1 cm) and liver (1.5×1.5 cm). The resected surface was covered with Surgicel® fabric or fibril type (Group A) or SurgiGuard® fabric or fibril type (Group B). Surgicel® and SurgiGuard® were randomized for attachment to the resected surface by fabric type (n=5) or fibril type (n=5). Blood loss was measured 5, 7, and 9 min after resection. Pigs were necropsied 6 weeks postoperatively to evaluate gross and histopathological changes. RESULTS: There was no significant difference in total blood loss between groups [spleen fabric: Group A vs. Group B, 4.38 g (2.74-6.43) vs. 3.41 g (2.46-4.65), p=0.436; spleen fibril: Group A vs. Group B, 3.44 g (2.82-6.07) vs. 3.60 g (2.03-6.09), p=0.971; liver fabric: Group A vs. Group B, 4.51 g (2.67-10.61) vs. 6.93 g (3.09-9.95), p=0.796; liver fibril: Group A vs. Group B, 3.32 g (2.50-8.78) vs. 3.70 g (2.32-5.84), p=0.971]. Histopathological analysis revealed no significant difference in toxicities related to Surgicel® or SurgiGuard® [inflammation, fibrosis, foreign bodies, and hemorrhage (spleen: p=0.333, 0.127, 0.751, and 1.000; liver: p=0.155, 0.751, 1.000, and 1.000, respectively)]. CONCLUSION: SurgiGuard® is as effective and non-toxic as Surgicel® in achieving hemostasis after porcine abdominal surgery.

Efficacy evaluation of SurgiGuard® in partially hepatectomized pigs.

BACKGROUNDS/AIMS: This study evaluated the hemostatic effects of a novel oxidized regenerated cellulose, SurgiGuard®, during liver surgery, using a reproducible and clinically relevant animal model. METHODS: Fifteen mini-pigs underwent left partial hepatectomy. They were randomized to treatment of the resected surface with SurgiGuard® (Group C [test], n=5), Surgicel® (Group B [reference], n=5), or nothing (Group A [control], n=5). Blood loss was measured 5, 7 and 9 min after resection. Time to hemostasis was recorded. Mini-pigs were necropsied 4 or 6 weeks postoperatively to evaluate toxicity changes and material dissolution. RESULTS: The median resected liver weight was 2.13 g (2.02-2.20) in control group, 2.04 g (2.01-2.13) in reference group, and 2.01 g (1.99-2.12) in test group (p=0.024). Median total blood loss was 57.18 g (52.02-59.54) in control group, 32.52 g (27.66-35.10) in reference group, and 35.52 g (25.70-38.71) in test group (p=0.008). Blood loss at 0-5 minutes and 7-9 minutes was significantly different between groups (p=0.009 and p=0.006, respectively). At necropsy, no hematomas, granulomas, or adhesions were noted in any group. Histopathological analysis revealed no changes suggesting toxicity related to SurgiGuard®. CONCLUSIONS: SurgiGuard® is as effective as Surgicel® in achieving hemostasis after porcine partial liver resection.