To compare a novel, fully synthetic, polyurethane based glue (MAR-1) to fibrin sealant in a partial liver resection rat model. METHODSAfter 50% resection of the lateral left liver lobe in male Wistar rats (n = 7/group...To compare a novel, fully synthetic, polyurethane based glue (MAR-1) to fibrin sealant in a partial liver resection rat model. METHODSAfter 50% resection of the lateral left liver lobe in male Wistar rats (n = 7/group/time point), MAR-1, Fibrin or NaCl was applied. After 14, 21 and 90 postoperative days, sealant degradation, intra-abdominal adhesions were scored, and histological examination of liver tissue was performed. RESULTS(Mean ± SEM) (MAR-1 vs Fibrin vs NaCl). Bleeding mass was significantly higher in NaCl (3.36 ± 0.51 g) compared to MAR-1 (1.44 ± 0.40 g) and Fibrin (1.16 ± 0.32 g). At 14 and 90 d, bleeding time was significantly lower in MAR-1 (6.00 ± 0.9 s; 13.57 ± 3.22 s) and Fibrin (3.00 ± 0.44 s; 22.2 ± 9.75 s) compared to NaCl (158.16 ± 11.36 s; 127.5 ± 23.3 s). ALT levels were significantly higher in MAR-1 (27.66 ± 1 U/L) compared to Fibrin (24.16 ± 0.98 U/L) and NaCl (23.85 ± 0.80 U/L). Intrabdominal adhesions were significantly lower in MAR-1 (11.22% ± 5.5%) compared to NaCl (58.57% ± 11.83%). Degradation of the glue was observed and MAR-1 showed almost no traces of glue in the abdominal cavity as compared to the Fibrin (10% ± 5% 14 d; 7% ± 3% 21 d). Survival showed no significant differences between the groups. CONCLUSIONCompared to Fibrin, MAR-1 showed similar hemostatic properties, no adverse effects, and is biocompatible. Further studies on adhesion strength and biodegradability of synthetic sealants are warranted.展开更多
In this study,the influence of a plasma electrolytic oxidation(PEO)surface treatment on a medical-grade WE43-based magnesium alloy is examined through an experimental and computational framework that considers the eff...In this study,the influence of a plasma electrolytic oxidation(PEO)surface treatment on a medical-grade WE43-based magnesium alloy is examined through an experimental and computational framework that considers the effects of localised corrosion features and mechanical properties throughout the corrosion process.First,a comprehensive in-vitro immersion study was performed on WE43-based tensile specimens with and without PEO surface modification,which included fully automated spatial reconstruction of the phenomenological features of corrosion through micro-CT scanning,followed by uniaxial tensile testing.Then the experimental data of both unmodified and PEO-modified groups were used to calibrate parameters of a finite element-based surface corrosion model.In-vitro,it was found that the WE43-PEO modified group had a significantly lower corrosion rate and maintained significantly higher mechanical properties than the unmodified.While corrosion rates were~50%lower in the WE43-PEO modified specimens,the local geometric features of corroding surfaces remained similar to the unmodified WE43 group,however evolving after almost the double amount of time.We were also able to quantitatively demonstrate that the PEO surface treatment on magnesium continued to protect samples from corrosion throughout the entire period tested,and not just in the early stages of corrosion.Using the results from the testing framework,the model parameters of the surface-based corrosion model were identified for both groups.This enabled,for the first time,in-silico prediction of the physical features of corrosion and the mechanical performance of both unmodified and PEO modified magnesium specimens.This simulation framework can enable future in-silico design and optimisation of bioabsorbable magnesium devices for load-bearing medical applications.展开更多
This study develops a three-dimensional automated detection framework(PitScan)that systematically evaluates the severity and phenomenology of pitting corrosion.This framework uses a python-based algorithm to analyse m...This study develops a three-dimensional automated detection framework(PitScan)that systematically evaluates the severity and phenomenology of pitting corrosion.This framework uses a python-based algorithm to analyse microcomputer-tomography scans(μCT)of cylindrical specimens undergoing corrosion.The approach systematically identifies several surface-based corrosion features,enabling full spatial characterisation of pitting parameters,including pit density,pit size,pit depth as well as pitting factor according to ASTM G46-94.Furthermore,it is used to evaluate pitting formation in tensile specimens of a Rare Earth Magnesium alloy undergoing corrosion,and relationships between key pitting parameters and mechanical performance are established.Results demonstrated that several of the parameters described in ASTM G46-94,including pit number,pit density and pitting factor,showed little correlation to mechanical performance.However,this study did identify that other parameters showed strong correlations with the ultimate tensile strength and these tended to be directly linked to the reduction of the cross-sectional area of the specimen.Specifically,our results indicate,that parameters directly linked to the loss of the cross-sectional area(e.g.minimum material width),are parameters that are most suited to provide an indication of a specimen’s mechanical performance.The automated detection framework developed in this study has the potential to provide a basis to standardise measurements of pitting corrosion across a range of metals and future prediction of mechanical strength over degradation time.展开更多
文摘To compare a novel, fully synthetic, polyurethane based glue (MAR-1) to fibrin sealant in a partial liver resection rat model. METHODSAfter 50% resection of the lateral left liver lobe in male Wistar rats (n = 7/group/time point), MAR-1, Fibrin or NaCl was applied. After 14, 21 and 90 postoperative days, sealant degradation, intra-abdominal adhesions were scored, and histological examination of liver tissue was performed. RESULTS(Mean ± SEM) (MAR-1 vs Fibrin vs NaCl). Bleeding mass was significantly higher in NaCl (3.36 ± 0.51 g) compared to MAR-1 (1.44 ± 0.40 g) and Fibrin (1.16 ± 0.32 g). At 14 and 90 d, bleeding time was significantly lower in MAR-1 (6.00 ± 0.9 s; 13.57 ± 3.22 s) and Fibrin (3.00 ± 0.44 s; 22.2 ± 9.75 s) compared to NaCl (158.16 ± 11.36 s; 127.5 ± 23.3 s). ALT levels were significantly higher in MAR-1 (27.66 ± 1 U/L) compared to Fibrin (24.16 ± 0.98 U/L) and NaCl (23.85 ± 0.80 U/L). Intrabdominal adhesions were significantly lower in MAR-1 (11.22% ± 5.5%) compared to NaCl (58.57% ± 11.83%). Degradation of the glue was observed and MAR-1 showed almost no traces of glue in the abdominal cavity as compared to the Fibrin (10% ± 5% 14 d; 7% ± 3% 21 d). Survival showed no significant differences between the groups. CONCLUSIONCompared to Fibrin, MAR-1 showed similar hemostatic properties, no adverse effects, and is biocompatible. Further studies on adhesion strength and biodegradability of synthetic sealants are warranted.
基金Funding support was also provided by the Irish Research Council(IRC)Government of Ireland Postgraduate Scholarship(GOIPG/2017/2102).
文摘In this study,the influence of a plasma electrolytic oxidation(PEO)surface treatment on a medical-grade WE43-based magnesium alloy is examined through an experimental and computational framework that considers the effects of localised corrosion features and mechanical properties throughout the corrosion process.First,a comprehensive in-vitro immersion study was performed on WE43-based tensile specimens with and without PEO surface modification,which included fully automated spatial reconstruction of the phenomenological features of corrosion through micro-CT scanning,followed by uniaxial tensile testing.Then the experimental data of both unmodified and PEO-modified groups were used to calibrate parameters of a finite element-based surface corrosion model.In-vitro,it was found that the WE43-PEO modified group had a significantly lower corrosion rate and maintained significantly higher mechanical properties than the unmodified.While corrosion rates were~50%lower in the WE43-PEO modified specimens,the local geometric features of corroding surfaces remained similar to the unmodified WE43 group,however evolving after almost the double amount of time.We were also able to quantitatively demonstrate that the PEO surface treatment on magnesium continued to protect samples from corrosion throughout the entire period tested,and not just in the early stages of corrosion.Using the results from the testing framework,the model parameters of the surface-based corrosion model were identified for both groups.This enabled,for the first time,in-silico prediction of the physical features of corrosion and the mechanical performance of both unmodified and PEO modified magnesium specimens.This simulation framework can enable future in-silico design and optimisation of bioabsorbable magnesium devices for load-bearing medical applications.
基金funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 813869.
文摘This study develops a three-dimensional automated detection framework(PitScan)that systematically evaluates the severity and phenomenology of pitting corrosion.This framework uses a python-based algorithm to analyse microcomputer-tomography scans(μCT)of cylindrical specimens undergoing corrosion.The approach systematically identifies several surface-based corrosion features,enabling full spatial characterisation of pitting parameters,including pit density,pit size,pit depth as well as pitting factor according to ASTM G46-94.Furthermore,it is used to evaluate pitting formation in tensile specimens of a Rare Earth Magnesium alloy undergoing corrosion,and relationships between key pitting parameters and mechanical performance are established.Results demonstrated that several of the parameters described in ASTM G46-94,including pit number,pit density and pitting factor,showed little correlation to mechanical performance.However,this study did identify that other parameters showed strong correlations with the ultimate tensile strength and these tended to be directly linked to the reduction of the cross-sectional area of the specimen.Specifically,our results indicate,that parameters directly linked to the loss of the cross-sectional area(e.g.minimum material width),are parameters that are most suited to provide an indication of a specimen’s mechanical performance.The automated detection framework developed in this study has the potential to provide a basis to standardise measurements of pitting corrosion across a range of metals and future prediction of mechanical strength over degradation time.