To create more useful, effective and safer anti-adhesion materials, we developed a thermally cross-linked gelatin film. In this study, we examined the physical properties of the film such as the physical strength and the adhesiveness to reveal the handling properties and biological properties, such as the anti-adhesion effect, the influence on cell proliferation, and the cytotoxicity to reveal the anti-adhesion mechanism, especially in comparison with the conventional hyaluronic acid and carboxymethylcellulose film (the conventional film). A tensile test under dry and wet conditions and shearing stress test showed that the gelatin film has significant higher maximum tensile stress and fracture strain than the conventional film. In the study using a rat model of cecum adhesion, the anti-adhesion effect of the gelatin film was significantly superior to that of the conventional film. In the cell proliferation test, the number of fibroblast cells on the gelatin film increased at each time point, while no cell proliferation was observed on the conventional film. Furthermore, in the cytotoxicity test using a colony assay and Live/Dead assay, the extract of the gelatin film had no cytotoxicity, while the extract of the conventional film had cytotoxicity considerably. These results suggest that the gelatin film provides better handling than the conventional film, due to better physical strength and ductility of the film. In addition, the gelatin film has a significantly greater anti-adhesion effect than the conventional film without any cytotoxicity. Therefore, the gelatin film is quite favorable as an anti-adhesion material. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 689-696, 2018.

To create anti-adhesive materials to be more effective and safer, we developed a thermally cross-linked gelatin film that showed superior anti-adhesive effects with excellent peritoneal regeneration. However, it may act as a convenient scaffold for tumor cell growth, thereby accelerating peritoneal dissemination when used in surgery for abdominal tumors. In this study, we tried to clarify this issue using mouse carcinomatous peritonitis models. First, we examined the in vitro tumor cell growth of mouse B16 melanoma or Colon26 cells on the gelatin film or the conventional hyarulonate/carboxymethylcellulose film. Tumor cell growth on each film was significantly lower than that of the control (no film). Next, we conducted the following in vivo experiments: After the parietal peritoneum was partially removed and covered with each film or without any film, mice were inoculated intraperitoneally with B16 melanoma or Colon26/Nluc cells expressing NanoLuc luciferase gene. At 7 days after the operation, we measured the weight of B16 melanoma tumors or the NanoLuc activity of Colon26/Nluc cells using in vivo imaging at the injured sites. There were no significant differences in the weight of the tumors and the NanoLuc activity among the three groups. We also observed the survival time of mice receiving the same operation and treatments. There was no significant difference in the survival time among the three groups. These results suggest that the gelatin film will likely not accelerate peritoneal dissemination as a convenient scaffold for tumor cell growth when used in surgery for abdominal tumors. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2122-2130, 2018.

AimAdhesion after pelvic surgery causes infertility, ectopic pregnancy, and ileus or abdominal pain. The materials currently available for clinical use are insufficient. The purpose of this study was to develop an anti-adhesive material that overcomes the limitations of conventional anti-adhesive agents.MethodsThe adhesion prevention effects of three methods - a two-layered sheet composed of gelatin film and gelatin sponge, Seprafilm and INTERCEED - were evaluated in 37 dogs. Anti-adhesive effects were investigated macroscopically and microscopically in a cauterized uterus adhesion model. Cell growth on the materials in vitro using human peritoneal mesothelial cells, fibroblasts and uterine smooth muscle cells were also evaluated.ResultsThe two-layered gelatin sheet had significantly superior anti-adhesive effects compared to the conventional materials (Seprafilm and INTERCEED). A single-cell layer of mature mesothelium formed three weeks after surgery in the gelatin group. Peritoneum regeneration in the Seprafilm and INTERCEED groups was delayed and incomplete in the early phase. Little inflammation around the materials occurred and cell growth was significantly proliferated with the gelatin sheet.ConclusionThe anti-adhesive effects of a two-layered gelatin sheet were superior to conventional agents in a cauterized canine uterus model, demonstrating early regeneration of the peritoneum, little inflammation and material endurance. The newly developed two-layered gelatin sheet is a useful option as an anti-adhesive agent for deeply injured and hemorrhagic sites.

Background and study aims: Recently, the shielding method with polyglycolic acid (PGA) fabric and fibrin glue (P-F method) has been reported to prevent serious complications after endoscopic submucosal dissection (ESD). However, the effectiveness and mechanism to prevent complications by this method remain unclear and the corresponding basic research has not been fully conducted. Methods and results: We examined the effectiveness and mechanism of the P-F method, using a surgical ESD model of canine stomach and in vitro experiments. In the model experiment treated by P-F method or no treatment (control), ulcer perforation or penetration occurred only in the control group, but not in the P-F group. Microscopically, the P-F group showed less damages of the ulcer lesion than that of the control group, showing thicker granulation tissues including PGA fibers on the third day and excellent mucosal regeneration on the fourteenth day. In vitro culture experiments showed that fibroblasts proliferated at a significantly higher rate on PGA than on fibrin or a complex thereof. However, under hydrochloric acid treatment, fibroblasts were protected by fibrin, followed by the complex of both, and PGA. Conclusion: The P-F method exhibited a protective effect against gastric juice by fibrin glue to reduce tissue damages and a scaffold function of PGA fabric to induce better granulation formation at the earlier phase, resulting in excellent long-term tissue repair, on ulcer lesion following ESD, although the results were based on basic experiments.

Event Abstract Back to Event The influences of thermally cross-linked gelatin film for intraperitoneal dissemination of tumor cells Hiroe Miyamoto1, Hiroyuki Tsujimoto1, Koki Yamanaka1, Han Pei1, Tsunehito Horii1, Hiroko Torii1, Yuki Ozamoto1 and Akeo Hagiwara1 1 Doshisha University, Department of Medical Life System, Japan Introduction: To prevent adhesion formation after abdominal surgery, we have developed a thermally cross-linked gelatin film and previously reported its superior anti-adhesive effects with excellent peritoneal regeneration[1]. However, it may act as a scaffold convenient for tumor cell growth, thereby accelerating peritoneal dissemination when used in surgery for abdominal tumors since the gelatin film is made from a degenerated product of collagen which is the most abundant extracellular matrix protein in mammals and has been used as a scaffold in the field of regeneration medicine. In this study, we tried to clarify this issue in in vitro and in vivo experiments using mouse B16 melanoma cells and its carcinomatous peritonitis model, compared with HA/CMC film which is an anti-adhesive material composed of polysaccharides and has been used clinically. Materials, Methods and Results: At first, we examined the influence of the gelatin film for in vitro tumor cell growth. B16 melanoma cells were cultured on the gelatin film, HA/CMC film or without any film. Each viable cell number was counted with time. As the result, B16 melanoma cells grew on the gelatin film and HA/CMC film significantly lower than those in the control group. Next, we examined the influence of the gelatin film for peritoneal dissemination using B16 melanoma carcinomatous peritonitis model. After laparotomy, small parts of bilateral parietal peritoneum were removed mechanically. The injured site were covered with the gelatin film, HA/CMC film or without any films (control). Then, each mouse was inoculated intraperitoneally with the B16 melanoma cells, which has intrinsic black melanin pigmentation. At 7 days after the inoculation, the tumor weight of B16 melanoma at the injured sites were measured. The result showed no significant differences of the tumor weight among three groups. Furthermore, there was also no significant differences of the mean survival time of the mice among three groups with the gelatin film, HA/CMC film or without any films. Discussion: In the in vitro experiment, the gelatin film as well as the HA/CMC inhibited the growth of B16 melanoma cells unexpectedly, compared with the control group. In the in vivo experiments using B16 melanoma carcinomatous peritonitis model, both films did not influence the tumor growth or the survival times of the mice inoculated with the tumors. These results suggests that the both types of films do not enhance the tumor growth at the injured sites at least. Conclusions: Thermally cross-linked gelatin film does not act as a scaffold convenient for tumor cell growth, thereby accelerating peritoneal dissemination, when used in surgery for abdominal tumors. References:[1] H. Tsujimoto, A. Tanzawa, H. Miyamoto, T. Horii, M. Tsuji, A. Kawasumi, A. Tamura, Z. Wang, R. Abe, S. Tanaka, K. Yamanaka, M. Matoba, H. Torii, Y. Ozamoto, H. Takamori, S. Suzuki, S. Morita, Y. Ikada, A. Hagiwara, “Biological properties of a thermally crosslinked gelatin film as a novel anti-adhesive material: Relationship between the biological properties and the extent of thermal crosslinking”, Journal of Biomedical Materials Research Part B: Applied Biomaterials. 2015; 103(7):1511-1518 Keywords: Regenerative Medicine, Scaffold, Biodegradable material, medical application Conference: 10th World Biomaterials Congress, Montréal, Canada, 17 May - 22 May, 2016. Presentation Type: Poster Topic: Biomaterials for cancer therapy Citation: Miyamoto H, Tsujimoto H, Yamanaka K, Pei H, Horii T, Torii H, Ozamoto Y and Hagiwara A (2016). The influences of thermally cross-linked gelatin film for intraperitoneal dissemination of tumor cells. Front. Bioeng. Biotechnol. Conference Abstract: 10th World Biomaterials Congress. doi: 10.3389/conf.FBIOE.2016.01.00139 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 27 Mar 2016; Published Online: 30 Mar 2016. Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Hiroe Miyamoto Hiroyuki Tsujimoto Koki Yamanaka Han Pei Tsunehito Horii Hiroko Torii Yuki Ozamoto Akeo Hagiwara Google Hiroe Miyamoto Hiroyuki Tsujimoto Koki Yamanaka Han Pei Tsunehito Horii Hiroko Torii Yuki Ozamoto Akeo Hagiwara Google Scholar Hiroe Miyamoto Hiroyuki Tsujimoto Koki Yamanaka Han Pei Tsunehito Horii Hiroko Torii Yuki Ozamoto Akeo Hagiwara PubMed Hiroe Miyamoto Hiroyuki Tsujimoto Koki Yamanaka Han Pei Tsunehito Horii Hiroko Torii Yuki Ozamoto Akeo Hagiwara Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Postoperative intra-abdominal or intrathoracic adhesions sometimes cause significant morbidity. We have designed three types of alginate-based treatments using strongly cross-linked (SL), weakly cross-linked (WL), and non-cross-linked (NL) alginate with calcium gluconate. In rat experiments, we compared the antiadhesive effects of the three types of alginate-based treatments, fibrin glue treatment (a standard treatment), and no treatment against adhesions caused by polyglycolic acid (PGA) mesh (PGA-induced adhesions). The antiadhesive materials were set on the PGA sheet fixed on the parietal peritoneum of the abdomen. Fifty-six days later, the adhesions were evaluated macroscopically by the adhesion scores and microscopically by hematoxylin-eosin staining and immunostaining. We also tested the fibroblast growth on the surface of the antiadhesive materials in vitro. The antiadhesive effects of WL and NL were superior to the no treatment and fibrin glue treatment. A microscopic evaluation confirmed that the PGA sheet was covered by a peritoneal layer constructed of well-differentiated mesothelial cells, and the inflammation was most improved in the NL and WL. The fibroblast growth was inhibited most on the surfaces of the NL and WL. These results suggest that either the WL or NL treatments are suitable for preventing PGA-induced adhesions compared to SL or the conventional treatment.

In order to prevent postoperative adhesion and the related complications, a thermally crosslinked gelatin (TCG) film was developed and the basic biological properties were examined, paying special attention to the relationship between these properties and the extent of crosslinking of the film. The gelatin films crosslinked thermally for five different time periods (0, 1, 3, 8, and 14 hours) were developed and the following tests were performed. Regarding the material characterization of the films, the water content, the water solubility, and the enzymatic degradation for collagenase were found to be closely related to the duration of thermal crosslinking. In an in vitro study conducted to examine the cell growth of fibroblasts cultured on the films, the degree of cell growth, except no crosslinked film, was less than that observed in the control group, thus suggesting that such effects of the films on fibroblast cell growth may be related with their anti-adhesive effects. In in vivo tests, the films crosslinked for longer time periods (3, 8, and 14 hours) were retained for longer after being implanted into the abdominal cavity in rats and showed a significant anti-adhesive effect in the rat cecum adhesion models, indicating that the biodegradability and anti-adhesive effects of the TCG films depend on the duration of thermal crosslinking. In order to develop useful and effective anti-adhesive gelatin film, it is very important to optimize duration of the thermal crosslinking.