Collagen Hydrogel Scaffold and Fibroblast Growth Factor-2 Accelerate Periodontal Healing of Class II Furcation Defects in Dog

Objective: Collagen hydrogel scaffold exhibits bio-safe properties and facilitates periodontal wound healing. However, regenerated tissue volume is insufficient. Fibroblast growth factor-2 (FGF2) up-regulates cell behaviors and subsequent wound healing. We evaluated whether periodontal wound healing is promoted by application of collagen hydrogel scaffold in combination with FGF2 in furcation defects in beagle dogs. Methods: Collagen hydrogel was fabricated from bovine type I collagen with an ascorbate-copper ion cross-linking system. Collagen hydrogel was mingled with FGF2 and injected into sponge-form collagen. Subsequently, FGF2 (50 μg)/collagen hydrogel scaffold and collagen hydrogel scaffold alone were implanted into class II furcation defects in dogs. In addition, no implantation was performed as a control. Histometric parameters were assessed at 10 days and 4 weeks after surgery. Result: FGF2 application to scaffold promoted considerable cell and tissue ingrowth containing numerous cells and blood vessel-like structure at day 10. At 4 weeks, reconstruction of alveolar bone was stimulated by implantation of scaffold loaded with FGF2. Furthermore, periodontal attachment, consisting of cementum-like tissue, periodontal ligament-like tissue and Sharpey’s fibers, was also repaired, indicating that FGF2-loaded scaffold guided self-assembly and then re-established the function of periodontal organs. Aberrant healing, such as ankylosis and root resorption, was not observed. Conclusion: FGF2-loaded collagen hydrogel scaffold possessed excellent biocompatibility and strongly promoted periodontal tissue engineering, including periodontal attachment re-organization

Feasibility study of an artificial placenta system consisting of a loop circuit configuration extracorporeal membrane oxygenation with a bridge circuit in the form of the umbilical arterial-venous connection.

We developed a new artificial placenta (AP) system consisting of a loop circuit configuration extracorporeal membrane oxygenation (ECMO) with a bridge circuit designed to be applied to the fetus in the form of an umbilical arterial-venous connection. We aimed to evaluate the feasibility of the AP system by performing a hydrodynamic simulation using a mechanical mock circulation system and fetal animal experiment. The effect of the working condition of the AP system on the fetal hemodynamics was evaluated by hydrodynamic simulation using a mechanical mock circulation system, assuming the weight of the fetus to be 2 kg. The AP system was introduced to two fetal goats at a gestational age of 135 days. The general conditions of the experimental animals were evaluated. The mock simulation showed that in an AP system with ECMO in the form of an umbilical arterial-venous connection in series, it could be difficult to maintain fetal hemodynamics when high ECMO flow was applied. The developed AP system could have high ECMO flow with less umbilical blood flow; however, the possibility of excessive load on the fetal right-sided heart should be noted. In the animal experiment, kid 1 (1.9 kg) was maintained on the AP system for 12 days and allowed to grow to term. In kid 2 (1.6 kg), the AP system could not be established because of the occlusion of the system by a thrombus. The developed AP system was feasible under both in vitro and in vivo conditions. Improvements in the AP system and management of the general fetal conditions are essential

Feasibility study of an artificial placenta system consisting of a loop circuit configuration extracorporeal membrane oxygenation with a bridge circuit in the form of the umbilical arterial-venous connection.

We developed a new artificial placenta (AP) system consisting of a loop circuit configuration extracorporeal membrane oxygenation (ECMO) with a bridge circuit designed to be applied to the fetus in the form of an umbilical arterial-venous connection. We aimed to evaluate the feasibility of the AP system by performing a hydrodynamic simulation using a mechanical mock circulation system and fetal animal experiment. The effect of the working condition of the AP system on the fetal hemodynamics was evaluated by hydrodynamic simulation using a mechanical mock circulation system, assuming the weight of the fetus to be 2 kg. The AP system was introduced to two fetal goats at a gestational age of 135 days. The general conditions of the experimental animals were evaluated. The mock simulation showed that in an AP system with ECMO in the form of an umbilical arterial-venous connection in series, it could be difficult to maintain fetal hemodynamics when high ECMO flow was applied. The developed AP system could have high ECMO flow with less umbilical blood flow; however, the possibility of excessive load on the fetal right-sided heart should be noted. In the animal experiment, kid 1 (1.9 kg) was maintained on the AP system for 12 days and allowed to grow to term. In kid 2 (1.6 kg), the AP system could not be established because of the occlusion of the system by a thrombus. The developed AP system was feasible under both in vitro and in vivo conditions. Improvements in the AP system and management of the general fetal conditions are essential