L. Heskin, R. Galvin, Jack Conroy, O. Traynor, Stephen Madden, C. Simms
INTRODUCTION The required fidelity of synthetic materials in surgical simulators to teach tissue handling and repair requirements should be as accurate as possible. There is a poor understanding of the relationship between choice of muscle surrogates and training outcome for trainee surgeons. To address this, the mechanical characteristics of several candidate synthetic muscle surrogates were measured, and their subjective biofidelity was qualitatively assessed by surgeons. METHODS Silicone was selected after assessing several material options and 16 silicone-based surrogates were evaluated. Three of the closest samples to muscle (Samples 1.1, 1.2, 1.3) and one with inserted longitudinal fibres (1.2F) were mechanically tested in the following: compression and tension, needle puncture force and suture pull-out in comparison with real muscle. The four samples were evaluated by 17 Plastic and Orthopaedic surgeons to determine their views of the fidelity with regard to the handling properties, needle insertion and ease of suture pull-out. RESULTS The mechanical testing showed the surrogates exhibited varying characteristics that matched some of the properties of muscle, though none recreated all the mechanical characteristics of native muscle. Good biofidelity was generally achieved for compression stiffness and needle puncture force, but it was evident that tensile stiff was too low for all samples. The pull-out forces were variable and too low, except for the sample with longitudinal fibres. In the qualitative assessment, the overall median scores for the four surrogate samples were all between 30 and 32 (possible range 9-45), indicating limited differentiation of the samples tested by the surgeons. CONCLUSIONS The surrogate materials showed a range of mechanical properties bracketing those of real muscle, thus presenting a suitable combination of candidates for use in simulators to attain the requirements as set out in the learning outcomes of muscle repair. However, despite significant mechanical differences between the samples, all surgeons found the samples to be similar to each other.
{"title":"Skeletal muscle surrogates for the acquisition of muscle repair skills in upper limb surgery.","authors":"L. Heskin, R. Galvin, Jack Conroy, O. Traynor, Stephen Madden, C. Simms","doi":"10.2139/ssrn.3998968","DOIUrl":"https://doi.org/10.2139/ssrn.3998968","url":null,"abstract":"INTRODUCTION\u0000The required fidelity of synthetic materials in surgical simulators to teach tissue handling and repair requirements should be as accurate as possible. There is a poor understanding of the relationship between choice of muscle surrogates and training outcome for trainee surgeons. To address this, the mechanical characteristics of several candidate synthetic muscle surrogates were measured, and their subjective biofidelity was qualitatively assessed by surgeons.\u0000\u0000\u0000METHODS\u0000Silicone was selected after assessing several material options and 16 silicone-based surrogates were evaluated. Three of the closest samples to muscle (Samples 1.1, 1.2, 1.3) and one with inserted longitudinal fibres (1.2F) were mechanically tested in the following: compression and tension, needle puncture force and suture pull-out in comparison with real muscle. The four samples were evaluated by 17 Plastic and Orthopaedic surgeons to determine their views of the fidelity with regard to the handling properties, needle insertion and ease of suture pull-out.\u0000\u0000\u0000RESULTS\u0000The mechanical testing showed the surrogates exhibited varying characteristics that matched some of the properties of muscle, though none recreated all the mechanical characteristics of native muscle. Good biofidelity was generally achieved for compression stiffness and needle puncture force, but it was evident that tensile stiff was too low for all samples. The pull-out forces were variable and too low, except for the sample with longitudinal fibres. In the qualitative assessment, the overall median scores for the four surrogate samples were all between 30 and 32 (possible range 9-45), indicating limited differentiation of the samples tested by the surgeons.\u0000\u0000\u0000CONCLUSIONS\u0000The surrogate materials showed a range of mechanical properties bracketing those of real muscle, thus presenting a suitable combination of candidates for use in simulators to attain the requirements as set out in the learning outcomes of muscle repair. However, despite significant mechanical differences between the samples, all surgeons found the samples to be similar to each other.","PeriodicalId":94117,"journal":{"name":"Journal of the mechanical behavior of biomedical materials","volume":"131 1","pages":"105216"},"PeriodicalIF":0.0,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42557289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A new CPC was developed in this study using a β-TCP powder mechano-chemically modified by ball-milling. The prototype CPC exhibits excellent fluidity for easy injection into bone defects; however, there is a risk of leakage from the defects immediately after implantation due to its high fluidity. The addition of poloxamer, an inverse thermoresponsive gelling agent, into CPC optimizes the fluidity. At lower temperatures, it forms a sol and maintains good injectability, whereas at the human body temperature, it transforms to a gel, reducing the fluidity and risk of leakage. In this study, the effects of poloxamer addition of 3, 5, and 10 mass% on the injectability, shape stability, and strength of the prototype CPC were evaluated. The calculated injectability of the prototype CPC pastes containing three different poloxamer contents was higher than that of the CPC paste without poloxamer for 15 min at 37 °C. Furthermore, the shape stability immediately after injection of the three CPC pastes with poloxamer was higher than that of the CPC paste without poloxamer. After 1 week of storage at 37 °C, the compressive strength and diametral tensile strength of the CPC compacts containing 10 mass% poloxamer were similar to those of the CPC compact without poloxamer. Additionally, the CPC compacts containing 10 mass% poloxamer exhibited clear plastic deformation after fracture. These results indicate that the addition of poloxamer to the prototype CPC could reduce the risk of leakage from bone defects and improve the fracture toughness with maintaining the injectability and strength.
{"title":"Effects of poloxamer additives on strength, injectability, and shape stability of beta-tricalcium phosphate cement modified using ball-milling.","authors":"Y. Kim, E. Uyama, K. Sekine, F. Kawano, K. Hamada","doi":"10.2139/ssrn.4041128","DOIUrl":"https://doi.org/10.2139/ssrn.4041128","url":null,"abstract":"A new CPC was developed in this study using a β-TCP powder mechano-chemically modified by ball-milling. The prototype CPC exhibits excellent fluidity for easy injection into bone defects; however, there is a risk of leakage from the defects immediately after implantation due to its high fluidity. The addition of poloxamer, an inverse thermoresponsive gelling agent, into CPC optimizes the fluidity. At lower temperatures, it forms a sol and maintains good injectability, whereas at the human body temperature, it transforms to a gel, reducing the fluidity and risk of leakage. In this study, the effects of poloxamer addition of 3, 5, and 10 mass% on the injectability, shape stability, and strength of the prototype CPC were evaluated. The calculated injectability of the prototype CPC pastes containing three different poloxamer contents was higher than that of the CPC paste without poloxamer for 15 min at 37 °C. Furthermore, the shape stability immediately after injection of the three CPC pastes with poloxamer was higher than that of the CPC paste without poloxamer. After 1 week of storage at 37 °C, the compressive strength and diametral tensile strength of the CPC compacts containing 10 mass% poloxamer were similar to those of the CPC compact without poloxamer. Additionally, the CPC compacts containing 10 mass% poloxamer exhibited clear plastic deformation after fracture. These results indicate that the addition of poloxamer to the prototype CPC could reduce the risk of leakage from bone defects and improve the fracture toughness with maintaining the injectability and strength.","PeriodicalId":94117,"journal":{"name":"Journal of the mechanical behavior of biomedical materials","volume":"130 1","pages":"105182"},"PeriodicalIF":0.0,"publicationDate":"2022-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46795075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Arteries are commonly assumed as symmetric cylindrical tubes with axisymmetric geometry and mechanical properties. However, their wall stress, structure and mechanical properties may become nonsymmetric when subject to torsion or complex mechanical loading. The objective of this study was to explore the nonsymmetric two fiber family constitutive models for arterial walls and examine the impact of this non-symmetry on the deformation and stress in arteries under mechanical loads. Our results demonstrated that nonsymmetric collagen fiber properties and alignment lead to interesting phenomena such as vessel twisting associated with axial stretch or pressurization. There are "magic" nonsymmetric fiber angles at which a vessel would not twist under given pressure and axial stretch. The nonsymmetric fiber properties and alignment (mean angle and dispersion) affects the torque-twist angle relationship as well as the axial stretch and pressurized inflation. These results illustrate the effects of nonsymmetric collagen fiber distribution and suggest that the Holzapfel-Gasser-Ogden models could be generalized to incorporate the nonsymmetric two fiber families for broader applications, especially when there is shear or torsion.
{"title":"Effects of material non-symmetry on the mechanical behavior of arterial wall.","authors":"Hai-Chao Han","doi":"10.2139/ssrn.3998969","DOIUrl":"https://doi.org/10.2139/ssrn.3998969","url":null,"abstract":"Arteries are commonly assumed as symmetric cylindrical tubes with axisymmetric geometry and mechanical properties. However, their wall stress, structure and mechanical properties may become nonsymmetric when subject to torsion or complex mechanical loading. The objective of this study was to explore the nonsymmetric two fiber family constitutive models for arterial walls and examine the impact of this non-symmetry on the deformation and stress in arteries under mechanical loads. Our results demonstrated that nonsymmetric collagen fiber properties and alignment lead to interesting phenomena such as vessel twisting associated with axial stretch or pressurization. There are \"magic\" nonsymmetric fiber angles at which a vessel would not twist under given pressure and axial stretch. The nonsymmetric fiber properties and alignment (mean angle and dispersion) affects the torque-twist angle relationship as well as the axial stretch and pressurized inflation. These results illustrate the effects of nonsymmetric collagen fiber distribution and suggest that the Holzapfel-Gasser-Ogden models could be generalized to incorporate the nonsymmetric two fiber families for broader applications, especially when there is shear or torsion.","PeriodicalId":94117,"journal":{"name":"Journal of the mechanical behavior of biomedical materials","volume":"129 1","pages":"105157"},"PeriodicalIF":0.0,"publicationDate":"2022-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44259784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
3D printing is a critical method for manufacturing metallic implants as it enables direct fabrication of intricate geometries and porous structures inaccessible to other manufacturing methods. Some common 3D printed porous structures are strut based (e.g. octet truss), triply periodic minimal surfaces (TPMS) (e.g. gyroid) or randomized (e.g. stochastic). When designed to be on the surface of bone interfacing implants, the surface porous region impacts short-term adhesion and friction, ultimately affecting implant stability prior to and during long-term osseointegration. In many orthopedic procedures, expulsion resistance is an essential design requirement, to prevent the risk of the implant migrating from the implantation site. While expulsion tests are universal, they are a poorly understood method to examine the bone-implant interface in determining the performance of an orthopedic implant. In this foundational study, we examine the expulsion behavior of metallic samples in synthetic Sawbone with systematically varied surface topography at increasing applied normal forces. The applied normal force and size of the sample were shown to have the strongest influence on expulsion force followed by surface structure. Compared to a polished sample control, certain 3D printed surface structures are up to 10x more expulsion resistant and should be considered in implants where prevention of implant migration before and during osseointegration is critical. Nonlinear relationships were discovered that reveal "crossover" in expulsion resistance as a function of applied load revealing that the ranking of the relative expulsion resistance of different samples can depend on the normal force selected. This new fundamental understanding has broad implications on both the design and potential standardized regulatory testing of textured orthopedic implants with tailored topologies.
{"title":"Effects of 3D printed surface topography and normal force on implant expulsion.","authors":"Amanda Heimbrook, Cambre N. Kelly, K. Gall","doi":"10.2139/ssrn.3978782","DOIUrl":"https://doi.org/10.2139/ssrn.3978782","url":null,"abstract":"3D printing is a critical method for manufacturing metallic implants as it enables direct fabrication of intricate geometries and porous structures inaccessible to other manufacturing methods. Some common 3D printed porous structures are strut based (e.g. octet truss), triply periodic minimal surfaces (TPMS) (e.g. gyroid) or randomized (e.g. stochastic). When designed to be on the surface of bone interfacing implants, the surface porous region impacts short-term adhesion and friction, ultimately affecting implant stability prior to and during long-term osseointegration. In many orthopedic procedures, expulsion resistance is an essential design requirement, to prevent the risk of the implant migrating from the implantation site. While expulsion tests are universal, they are a poorly understood method to examine the bone-implant interface in determining the performance of an orthopedic implant. In this foundational study, we examine the expulsion behavior of metallic samples in synthetic Sawbone with systematically varied surface topography at increasing applied normal forces. The applied normal force and size of the sample were shown to have the strongest influence on expulsion force followed by surface structure. Compared to a polished sample control, certain 3D printed surface structures are up to 10x more expulsion resistant and should be considered in implants where prevention of implant migration before and during osseointegration is critical. Nonlinear relationships were discovered that reveal \"crossover\" in expulsion resistance as a function of applied load revealing that the ranking of the relative expulsion resistance of different samples can depend on the normal force selected. This new fundamental understanding has broad implications on both the design and potential standardized regulatory testing of textured orthopedic implants with tailored topologies.","PeriodicalId":94117,"journal":{"name":"Journal of the mechanical behavior of biomedical materials","volume":"130 1","pages":"105208"},"PeriodicalIF":0.0,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48213337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jonathan C. J. Wei, Ian D. Cartmill, M. Kendall, M. Crichton
With the development of wearable technologies, the interfacial properties of skin and devices have become much more important. For research and development purposes, porcine skin is often used to evaluate device performance, but the differences between in vivo, in situ and ex vivo porcine skin mechanical properties can potentially misdirect investigators during the development of their technology. In this study, we investigated the significant changes to mechanical properties with and without perfusion (in vivo versus in vitro tissue). The device focus for this study was a skin-targeting Nanopatch vaccine microneedle device, employed to assess the variance to key skin engagement parameters - penetration depth and delivery efficiency - due to different tissue conditions. The patches were coated with fluorescent or 14C radiolabelled formulations for penetration depth and delivery efficiency quantification in vivo, and at time points up to 4 h post mortem. An immediate cessation of blood circulation saw mean microneedle penetration depth fell from ∼100 μm to ∼55 μm (∼45%). Stiffening of underlying tissues as a result of rigor mortis then augmented the penetration depths at the 4 h timepoint back to ∼100 μm, insignificantly different (p = 0.0595) when compared with in vivo. The highest delivery efficiency of formulation into the skin (dose measured in the skin excluding leftover dose on skin and patch surfaces) was also observed at this time point of ∼25%, up from ∼2% in vivo. Data obtained herein progresses medical device development, highlighting the need to consider the state and muscle tissues when evaluating prototypes on cadavers.
{"title":"In vivo, in situ and ex vivo comparison of porcine skin for microprojection array penetration depth, delivery efficiency and elastic modulus assessment.","authors":"Jonathan C. J. Wei, Ian D. Cartmill, M. Kendall, M. Crichton","doi":"10.2139/ssrn.3998970","DOIUrl":"https://doi.org/10.2139/ssrn.3998970","url":null,"abstract":"With the development of wearable technologies, the interfacial properties of skin and devices have become much more important. For research and development purposes, porcine skin is often used to evaluate device performance, but the differences between in vivo, in situ and ex vivo porcine skin mechanical properties can potentially misdirect investigators during the development of their technology. In this study, we investigated the significant changes to mechanical properties with and without perfusion (in vivo versus in vitro tissue). The device focus for this study was a skin-targeting Nanopatch vaccine microneedle device, employed to assess the variance to key skin engagement parameters - penetration depth and delivery efficiency - due to different tissue conditions. The patches were coated with fluorescent or 14C radiolabelled formulations for penetration depth and delivery efficiency quantification in vivo, and at time points up to 4 h post mortem. An immediate cessation of blood circulation saw mean microneedle penetration depth fell from ∼100 μm to ∼55 μm (∼45%). Stiffening of underlying tissues as a result of rigor mortis then augmented the penetration depths at the 4 h timepoint back to ∼100 μm, insignificantly different (p = 0.0595) when compared with in vivo. The highest delivery efficiency of formulation into the skin (dose measured in the skin excluding leftover dose on skin and patch surfaces) was also observed at this time point of ∼25%, up from ∼2% in vivo. Data obtained herein progresses medical device development, highlighting the need to consider the state and muscle tissues when evaluating prototypes on cadavers.","PeriodicalId":94117,"journal":{"name":"Journal of the mechanical behavior of biomedical materials","volume":"130 1","pages":"105187"},"PeriodicalIF":0.0,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46782007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yiliang Wang, J. Ghaboussi, Cameron Hoerig, M. Insana
The Autoprogressive (AutoP) method is a data-driven inverse method that leverages finite element analysis (FEA) and machine learning (ML) techniques to build constitutive relationships from measured force and displacement data. Previous applications of AutoP in tissue-like media have focused on linear elastic mechanical behavior as the target object is infinitesimally compressed. In this study, we extended the application of AutoP in characterizing nonlinear elastic mechanical behavior as the target object undergoes finite compressive deformation. Guided by the prior of nonlinear media, we modified the training data generated by AutoP to speed its ability to learn to model deformations. AutoP training was validated using both synthetic and experimental data recorded from 3D objects. Force-displacement measurements were obtained using ultrasonic imaging from heterogeneous agar-gelatin phantoms. Measurement on samples of phantom components were analyzed to obtain independent measurements of material properties. Comparisons validated the material properties found from neural network constitutive models (NNCMs) trained using AutoP. Results were found to be robust to measurement errors and spatial variations in material properties.
{"title":"A data-driven approach to characterizing nonlinear elastic behavior of soft materials.","authors":"Yiliang Wang, J. Ghaboussi, Cameron Hoerig, M. Insana","doi":"10.2139/ssrn.4015084","DOIUrl":"https://doi.org/10.2139/ssrn.4015084","url":null,"abstract":"The Autoprogressive (AutoP) method is a data-driven inverse method that leverages finite element analysis (FEA) and machine learning (ML) techniques to build constitutive relationships from measured force and displacement data. Previous applications of AutoP in tissue-like media have focused on linear elastic mechanical behavior as the target object is infinitesimally compressed. In this study, we extended the application of AutoP in characterizing nonlinear elastic mechanical behavior as the target object undergoes finite compressive deformation. Guided by the prior of nonlinear media, we modified the training data generated by AutoP to speed its ability to learn to model deformations. AutoP training was validated using both synthetic and experimental data recorded from 3D objects. Force-displacement measurements were obtained using ultrasonic imaging from heterogeneous agar-gelatin phantoms. Measurement on samples of phantom components were analyzed to obtain independent measurements of material properties. Comparisons validated the material properties found from neural network constitutive models (NNCMs) trained using AutoP. Results were found to be robust to measurement errors and spatial variations in material properties.","PeriodicalId":94117,"journal":{"name":"Journal of the mechanical behavior of biomedical materials","volume":"92 1","pages":"105178"},"PeriodicalIF":0.0,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91339036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Myat Myat-Htun, A. M. Mohd Noor, M. Kawashita, Y. B. Baba Ismail
Dense iron-doped akermanite ceramics with 0.3, 0.6 and 0.9 mol% of Fe3+ were synthesized via high-speed planetary ball milling and subsequently subjected to sintering at 1200 and 1250 °C. The aim of the current work was to investigate the effect of trivalent iron (Fe3+) in tuning the physicomechanical and in vitro biological properties of akermanite. The incorporation of Fe3+ into akermanite host and sintering at a high temperature of 1200 °C resulted in a synergistic effect in enhancing the sinterability and densification of akermanite ceramics. Although varying the Fe3+ content, it was found that similar densification and mechanical properties (i.e., diametral tensile strength, Vickers microhardness and fracture toughness) were observed for the doped ceramics at 1250 °C, indicating that this newly developed formulation is temperature-dependent. Fe3+-doped akermanite ceramics revealed greater in vitro bioactivity as compared to undoped akermanite, demonstrated by better coverage of needle-like apatite precipitates after 21 days of immersion in simulated body fluid. Additionally, Rat-1 cells cultured in direct contact with Fe3+-doped akermanite ceramics showed almost double levels of cell proliferation than their undoped counterpart on both 3 and 7 days of culture. Our finding suggests that 0.9Fe-AK ceramic is a suitable formulation to be considered for future bone substitute material as it provides sufficient mechanical strength as well as good bioactivity and the ability to encourage cell proliferation.
{"title":"Tailoring mechanical and in vitro biological properties of calcium‒silicate based bioceramic through iron doping in developing future material.","authors":"Myat Myat-Htun, A. M. Mohd Noor, M. Kawashita, Y. B. Baba Ismail","doi":"10.2139/ssrn.3962042","DOIUrl":"https://doi.org/10.2139/ssrn.3962042","url":null,"abstract":"Dense iron-doped akermanite ceramics with 0.3, 0.6 and 0.9 mol% of Fe3+ were synthesized via high-speed planetary ball milling and subsequently subjected to sintering at 1200 and 1250 °C. The aim of the current work was to investigate the effect of trivalent iron (Fe3+) in tuning the physicomechanical and in vitro biological properties of akermanite. The incorporation of Fe3+ into akermanite host and sintering at a high temperature of 1200 °C resulted in a synergistic effect in enhancing the sinterability and densification of akermanite ceramics. Although varying the Fe3+ content, it was found that similar densification and mechanical properties (i.e., diametral tensile strength, Vickers microhardness and fracture toughness) were observed for the doped ceramics at 1250 °C, indicating that this newly developed formulation is temperature-dependent. Fe3+-doped akermanite ceramics revealed greater in vitro bioactivity as compared to undoped akermanite, demonstrated by better coverage of needle-like apatite precipitates after 21 days of immersion in simulated body fluid. Additionally, Rat-1 cells cultured in direct contact with Fe3+-doped akermanite ceramics showed almost double levels of cell proliferation than their undoped counterpart on both 3 and 7 days of culture. Our finding suggests that 0.9Fe-AK ceramic is a suitable formulation to be considered for future bone substitute material as it provides sufficient mechanical strength as well as good bioactivity and the ability to encourage cell proliferation.","PeriodicalId":94117,"journal":{"name":"Journal of the mechanical behavior of biomedical materials","volume":"128 1","pages":"105122"},"PeriodicalIF":0.0,"publicationDate":"2022-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44212323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Bitencourt, B. Hatton, N. Bastos-Bitencourt, Daniela Micheline Dos Santos, A. Pesqueira, G. de Souza
PURPOSE To develop and to characterize a hybrid interface between yttria-stabilized zirconia (Y-TZP) transformed layer and silica-based nanofilm to enable a better bonding between Y-TZP and a veneering ceramic. MATERIAL AND METHODS Sixty-six fully-sintered rectangular Y-TZP specimens were distributed into 6 groups, according to the surface treatment applied: C (control): no treatment; Al: 27 μm-alumina particle abrasion; Ht: hydrothermal treatment in autoclave for 15h; Si20: 20 cycles of silica deposition using room-temperature atomic layer deposition (RT-ALD); Si40: 40 cycles of RT-ALD; Ht + Si40: hydrothermal treatment followed by 40 cycles of RT-ALD. RT-ALD was performed by the sequential exposure of specimens to vapor of tetramethoxysilane orthosilicate (TMOS) and ammonium hydroxide (NH4OH). Y-TZP surface wettability and shear bond strength (SBS) between Y-TZP and the veneering ceramic were analyzed for all groups after surface treatments. One-way ANOVA and Tukey's HSD test were used for data analysis (p ≤ 0.05). RESULTS The highest contact angle was observed for the control group (64.46 ± 6.09 θ), while the lowest values (p < 0.001) were presented after Si20 (29.85 ± 4.23 θ) and Si40 (30.37 ± 5.51 θ) treatments. Hydrothermal treatment (49.3 ± 2.69 θ) and alumina abrasion (45.84 ± 4.12 θ) resulted in intermediate contact angle values. The highest SBS values were observed for Al (16.74 ± 1.68 MPa) and Ht (15.27 ± 2.11 MPa) groups (p < 0.018). Groups Si20 (9.66 ± 1.22 MPa), Si40 (9.33 ± 2.11 MPa), Ht + Si40 (9.37 ± 1.02 MPa) and C (12.54 ± 2.64 MPa) all resulted in similar SBS results (p > 0.998). CONCLUSION The experimental treatments proposed enhanced surface wettability, but shear bond strength between Y-TZP and veneering ceramic was not improved. Alumina particle-abrasion improved SBS values while a decrease in wettability was observed.
{"title":"Silica deposition on zirconia via room-temperature atomic layer deposition (RT-ALD): Effect on bond strength to veneering ceramic.","authors":"S. Bitencourt, B. Hatton, N. Bastos-Bitencourt, Daniela Micheline Dos Santos, A. Pesqueira, G. de Souza","doi":"10.2139/ssrn.4030484","DOIUrl":"https://doi.org/10.2139/ssrn.4030484","url":null,"abstract":"PURPOSE\u0000To develop and to characterize a hybrid interface between yttria-stabilized zirconia (Y-TZP) transformed layer and silica-based nanofilm to enable a better bonding between Y-TZP and a veneering ceramic.\u0000\u0000\u0000MATERIAL AND METHODS\u0000Sixty-six fully-sintered rectangular Y-TZP specimens were distributed into 6 groups, according to the surface treatment applied: C (control): no treatment; Al: 27 μm-alumina particle abrasion; Ht: hydrothermal treatment in autoclave for 15h; Si20: 20 cycles of silica deposition using room-temperature atomic layer deposition (RT-ALD); Si40: 40 cycles of RT-ALD; Ht + Si40: hydrothermal treatment followed by 40 cycles of RT-ALD. RT-ALD was performed by the sequential exposure of specimens to vapor of tetramethoxysilane orthosilicate (TMOS) and ammonium hydroxide (NH4OH). Y-TZP surface wettability and shear bond strength (SBS) between Y-TZP and the veneering ceramic were analyzed for all groups after surface treatments. One-way ANOVA and Tukey's HSD test were used for data analysis (p ≤ 0.05).\u0000\u0000\u0000RESULTS\u0000The highest contact angle was observed for the control group (64.46 ± 6.09 θ), while the lowest values (p < 0.001) were presented after Si20 (29.85 ± 4.23 θ) and Si40 (30.37 ± 5.51 θ) treatments. Hydrothermal treatment (49.3 ± 2.69 θ) and alumina abrasion (45.84 ± 4.12 θ) resulted in intermediate contact angle values. The highest SBS values were observed for Al (16.74 ± 1.68 MPa) and Ht (15.27 ± 2.11 MPa) groups (p < 0.018). Groups Si20 (9.66 ± 1.22 MPa), Si40 (9.33 ± 2.11 MPa), Ht + Si40 (9.37 ± 1.02 MPa) and C (12.54 ± 2.64 MPa) all resulted in similar SBS results (p > 0.998).\u0000\u0000\u0000CONCLUSION\u0000The experimental treatments proposed enhanced surface wettability, but shear bond strength between Y-TZP and veneering ceramic was not improved. Alumina particle-abrasion improved SBS values while a decrease in wettability was observed.","PeriodicalId":94117,"journal":{"name":"Journal of the mechanical behavior of biomedical materials","volume":"129 1","pages":"105142"},"PeriodicalIF":0.0,"publicationDate":"2022-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43316320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alberto Terzolo, L. Bailly, Laurent Orgéas, T. Cochereau, Nathalie Henrich Bernardoni
Composed of collagen, elastin and muscular fibrous networks, vocal folds are soft laryngeal multi-layered tissues owning remarkable vibro-mechanical performances. However, the impact of their histological features on their overall mechanical properties still remains elusive. Thereby, this study presents a micro-mechanical hyperelastic model able to describe the 3D fibrous architecture and the surrounding matrices of the vocal-fold sublayers, and to predict their mechanical behavior. For each layer, the model parameters were identified using available histo-mechanical data, including their quasi-static response for key physiological loading paths, i.e., longitudinal tension, transverse compression and longitudinal shear. Regardless of the loading path, it is shown how macroscale nonlinear, anisotropic tissue responses are inherited from the fiber scale. Scenarios of micro-mechanisms are predicted, highlighting the major role of 3D fiber orientation in tension, steric hindrance in compression, and matrix contribution in shear. Finally, combining these predictions to vibrating hyperelastic Timoshenko beam's theory, the impact of the fibrous architecture of the upper layers on vocal-fold vibratory properties is emphasized.
{"title":"A micro-mechanical model for the fibrous tissues of vocal folds.","authors":"Alberto Terzolo, L. Bailly, Laurent Orgéas, T. Cochereau, Nathalie Henrich Bernardoni","doi":"10.2139/ssrn.3962822","DOIUrl":"https://doi.org/10.2139/ssrn.3962822","url":null,"abstract":"Composed of collagen, elastin and muscular fibrous networks, vocal folds are soft laryngeal multi-layered tissues owning remarkable vibro-mechanical performances. However, the impact of their histological features on their overall mechanical properties still remains elusive. Thereby, this study presents a micro-mechanical hyperelastic model able to describe the 3D fibrous architecture and the surrounding matrices of the vocal-fold sublayers, and to predict their mechanical behavior. For each layer, the model parameters were identified using available histo-mechanical data, including their quasi-static response for key physiological loading paths, i.e., longitudinal tension, transverse compression and longitudinal shear. Regardless of the loading path, it is shown how macroscale nonlinear, anisotropic tissue responses are inherited from the fiber scale. Scenarios of micro-mechanisms are predicted, highlighting the major role of 3D fiber orientation in tension, steric hindrance in compression, and matrix contribution in shear. Finally, combining these predictions to vibrating hyperelastic Timoshenko beam's theory, the impact of the fibrous architecture of the upper layers on vocal-fold vibratory properties is emphasized.","PeriodicalId":94117,"journal":{"name":"Journal of the mechanical behavior of biomedical materials","volume":"128 1","pages":"105118"},"PeriodicalIF":0.0,"publicationDate":"2022-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42020213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
X. Yuan, Yubin Xu, T. Lu, F. He, Luhui Zhang, Qixuan He, Jiandong Ye
Although hydroxyapatite (HA) bioceramic has excellent biocompatibility and osteoconductivity, its high chemical stability results in slow degradation which affects osteogenesis, angiogenesis and clinical applications. Silica-based bioglass (BG) with superior biological performance has been introduced into HA bioceramic to overcome this insufficiency; however, the composite bioceramics are usually prepared by traditional mechanical mixture of HA and BG powders, which tremendously weakens their mechanical performance. In this research, BG-modified HA bioceramics were prepared by the use of BG sol encapsulated HA powders. The results showed that introducing 1 and 3 wt% BG allowed the HA-based bioceramics to maintain the high compressive strength (>300 MPa), improved the apatite mineralization activity, and played an important role in cellular response. The bioceramic modified with 1 wt% BG (1BG/HA) remarkably enhanced in vitro cell proliferation, osteogenic and angiogenic activities. This present work provides a new strategy to improve the biological performance of bioceramics and the HA-based bioceramics with 1 wt% BG can be as a promising candidate material for bone repair.
{"title":"Enhancing the bioactivity of hydroxyapatite bioceramic via encapsulating with silica-based bioactive glass sol.","authors":"X. Yuan, Yubin Xu, T. Lu, F. He, Luhui Zhang, Qixuan He, Jiandong Ye","doi":"10.2139/ssrn.3981401","DOIUrl":"https://doi.org/10.2139/ssrn.3981401","url":null,"abstract":"Although hydroxyapatite (HA) bioceramic has excellent biocompatibility and osteoconductivity, its high chemical stability results in slow degradation which affects osteogenesis, angiogenesis and clinical applications. Silica-based bioglass (BG) with superior biological performance has been introduced into HA bioceramic to overcome this insufficiency; however, the composite bioceramics are usually prepared by traditional mechanical mixture of HA and BG powders, which tremendously weakens their mechanical performance. In this research, BG-modified HA bioceramics were prepared by the use of BG sol encapsulated HA powders. The results showed that introducing 1 and 3 wt% BG allowed the HA-based bioceramics to maintain the high compressive strength (>300 MPa), improved the apatite mineralization activity, and played an important role in cellular response. The bioceramic modified with 1 wt% BG (1BG/HA) remarkably enhanced in vitro cell proliferation, osteogenic and angiogenic activities. This present work provides a new strategy to improve the biological performance of bioceramics and the HA-based bioceramics with 1 wt% BG can be as a promising candidate material for bone repair.","PeriodicalId":94117,"journal":{"name":"Journal of the mechanical behavior of biomedical materials","volume":"128 1","pages":"105104"},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44391377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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