P. D'andrea, Deborah Civita, M. Cok, L. Ulloa Severino, F. Vita, D. Scaini, L. Casalis, P. Lorenzon, I. Donati, A. Bandiera
Background The biochemical, mechanical and topographic properties of extracellular matrix are crucially involved in determining skeletal muscle cell morphogenesis, proliferation and differentiation. Human elastin-like polypeptides (HELPs) are recombinant biomimetic proteins designed to mimic some properties of the native matrix protein; when employed as myoblast adhesion substrates, they stimulate in vitro myogenesis. Given the influence that the biophysical properties of extracellular matrix have on skeletal muscle cells, the aim of this work was to investigate the effects of HELP hydrogels on myoblasts’ viability and functions. Methods We recently synthesized a novel polypeptide, HELPc, by fusing the elastin-like backbone to a 41aa sequence present in the α2 chain of type IV collagen, containing two arginyl-glycyl-aspartic acid (RGD) motifs. To obtain hydrogels, the enzymatic cross-linking of the HELPc was accomplished by transglutaminase. Here, we employed both non-cross-linked HELPc glass coatings and cross-linked HELPc hydrogels at different monomer densities, as adhesion substrates for C2C12 cells, used as a myoblast model. Results By comparing cell adhesion, proliferation and differentiation, we revealed several striking differences. Depending on support rigidity, adhesion to HELPc substrates dictated cell morphology, spreading, focal adhesion formation and cytoskeletal organization. Hydrogels greatly stimulated cell proliferation, particularly in low-serum medium, and partially inhibited myogenic differentiation. Conclusions On the whole, the results underline the potential of these genetically engineered polypeptides as a tool for dissecting crucial steps in myogenesis.
{"title":"Myoblast Adhesion, Proliferation and Differentiation on Human Elastin-Like Polypeptide (HELP) Hydrogels","authors":"P. D'andrea, Deborah Civita, M. Cok, L. Ulloa Severino, F. Vita, D. Scaini, L. Casalis, P. Lorenzon, I. Donati, A. Bandiera","doi":"10.5301/jabfm.5000331","DOIUrl":"https://doi.org/10.5301/jabfm.5000331","url":null,"abstract":"Background The biochemical, mechanical and topographic properties of extracellular matrix are crucially involved in determining skeletal muscle cell morphogenesis, proliferation and differentiation. Human elastin-like polypeptides (HELPs) are recombinant biomimetic proteins designed to mimic some properties of the native matrix protein; when employed as myoblast adhesion substrates, they stimulate in vitro myogenesis. Given the influence that the biophysical properties of extracellular matrix have on skeletal muscle cells, the aim of this work was to investigate the effects of HELP hydrogels on myoblasts’ viability and functions. Methods We recently synthesized a novel polypeptide, HELPc, by fusing the elastin-like backbone to a 41aa sequence present in the α2 chain of type IV collagen, containing two arginyl-glycyl-aspartic acid (RGD) motifs. To obtain hydrogels, the enzymatic cross-linking of the HELPc was accomplished by transglutaminase. Here, we employed both non-cross-linked HELPc glass coatings and cross-linked HELPc hydrogels at different monomer densities, as adhesion substrates for C2C12 cells, used as a myoblast model. Results By comparing cell adhesion, proliferation and differentiation, we revealed several striking differences. Depending on support rigidity, adhesion to HELPc substrates dictated cell morphology, spreading, focal adhesion formation and cytoskeletal organization. Hydrogels greatly stimulated cell proliferation, particularly in low-serum medium, and partially inhibited myogenic differentiation. Conclusions On the whole, the results underline the potential of these genetically engineered polypeptides as a tool for dissecting crucial steps in myogenesis.","PeriodicalId":51074,"journal":{"name":"Journal of Applied Biomaterials & Biomechanics","volume":"224 1","pages":"43 - 53"},"PeriodicalIF":0.0,"publicationDate":"2016-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5301/jabfm.5000331","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70592886","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}
Background Auxetic materials tend to exhibit stretching in the direction of the applied load as well as in the perpendicular direction. This may be an inherent property of the material, or it might be a particular structural characteristic that confers it with auxetic properties. In this study, the auxetic properties of a rotating squares auxetic design were utilized in tandem with a stretching mechanism to manufacture a device that offers the advantages of adjustable pore size and hence tunable drug delivery characteristics. Methods An auxetic polyurethane film was fabricated through the polymer casting technique. An acrylonitrile-butadiene-styrene (ABS) plastic mold for polymer casting was made through additive manufacturing. Stereolithography was used for fabrication of the mechanism that controlled pore size of the polymeric auxetic film. A laminate arrangement of the film and the mechanism was devised, through which movement of the mechanism controlled stretching of the auxetic film underneath. Results Results were analyzed through image processing. It was observed that a 2-dimensional increase (in length and width) of the auxetic film took place that corresponded to an increase in pore size of the film. Several mathematical correlations were drawn up. Conclusions It may be concluded that the first factor controlling drug release kinetics is the pore size of the film. This study explored a prototype mechanism that has the potential for being used in devices for controlled drug delivery or in smart bandage systems that may enhance wound healing in chronic wound treatment.
{"title":"Macro-Scale Model Study of a Tunable Drug Dispensation Mechanism for Controlled Drug Delivery in Potential Wound-Healing Applications","authors":"Mariam Mir, Umar Ansari, Murtaza Najabat Ali","doi":"10.5301/jabfm.5000280","DOIUrl":"https://doi.org/10.5301/jabfm.5000280","url":null,"abstract":"Background Auxetic materials tend to exhibit stretching in the direction of the applied load as well as in the perpendicular direction. This may be an inherent property of the material, or it might be a particular structural characteristic that confers it with auxetic properties. In this study, the auxetic properties of a rotating squares auxetic design were utilized in tandem with a stretching mechanism to manufacture a device that offers the advantages of adjustable pore size and hence tunable drug delivery characteristics. Methods An auxetic polyurethane film was fabricated through the polymer casting technique. An acrylonitrile-butadiene-styrene (ABS) plastic mold for polymer casting was made through additive manufacturing. Stereolithography was used for fabrication of the mechanism that controlled pore size of the polymeric auxetic film. A laminate arrangement of the film and the mechanism was devised, through which movement of the mechanism controlled stretching of the auxetic film underneath. Results Results were analyzed through image processing. It was observed that a 2-dimensional increase (in length and width) of the auxetic film took place that corresponded to an increase in pore size of the film. Several mathematical correlations were drawn up. Conclusions It may be concluded that the first factor controlling drug release kinetics is the pore size of the film. This study explored a prototype mechanism that has the potential for being used in devices for controlled drug delivery or in smart bandage systems that may enhance wound healing in chronic wound treatment.","PeriodicalId":51074,"journal":{"name":"Journal of Applied Biomaterials & Biomechanics","volume":"15 1","pages":"63 - 69"},"PeriodicalIF":0.0,"publicationDate":"2016-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5301/jabfm.5000280","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70592435","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}
C. Colpitts, A. Ektesabi, R. Wyatt, B. D. Crawford, Amirkianoosh Kiani
Background In this study, we investigated a method to produce bioactive hybrid amorphous silicon and silicon oxide patterns using nanosecond laser pulses. Methods Microscale line patterns were made by laser pulses on silicon wafers at different frequencies (25, 70 and 100 kHz), resulting in ablation patterns with frequency-dependent physical and chemical properties. Results Incubating the laser-treated silicon substrates with simulated body fluid demonstrated that the physicochemical properties of the laser-treated samples were stable under these conditions, and favored the deposition of bone-like apatite. More importantly, while NIH 3T3 fibroblasts did colonize the untreated regions of the silicon wafers, they showed a strong preference for the laser-treated regions, and further discriminated between substrates treated with different frequencies. Conclusions Taken together, these data suggest that laser materials processing of silicon-based devices is a promising avenue to pursue in the production of biosensors and other bionic devices.
{"title":"Mammalian Fibroblast Cells Show Strong Preference for Laser-Generated Hybrid Amorphous Silicon-SiO2 Textures","authors":"C. Colpitts, A. Ektesabi, R. Wyatt, B. D. Crawford, Amirkianoosh Kiani","doi":"10.5301/jabfm.5000327","DOIUrl":"https://doi.org/10.5301/jabfm.5000327","url":null,"abstract":"Background In this study, we investigated a method to produce bioactive hybrid amorphous silicon and silicon oxide patterns using nanosecond laser pulses. Methods Microscale line patterns were made by laser pulses on silicon wafers at different frequencies (25, 70 and 100 kHz), resulting in ablation patterns with frequency-dependent physical and chemical properties. Results Incubating the laser-treated silicon substrates with simulated body fluid demonstrated that the physicochemical properties of the laser-treated samples were stable under these conditions, and favored the deposition of bone-like apatite. More importantly, while NIH 3T3 fibroblasts did colonize the untreated regions of the silicon wafers, they showed a strong preference for the laser-treated regions, and further discriminated between substrates treated with different frequencies. Conclusions Taken together, these data suggest that laser materials processing of silicon-based devices is a promising avenue to pursue in the production of biosensors and other bionic devices.","PeriodicalId":51074,"journal":{"name":"Journal of Applied Biomaterials & Biomechanics","volume":"15 1","pages":"84 - 92"},"PeriodicalIF":0.0,"publicationDate":"2016-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5301/jabfm.5000327","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70593096","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}
Xiaoling He, Yuxin Zhao, Z. Jin, Yuhan Su, Huiqin An, Lili Ge, Dongsheng Wei, Li Chen
Background The aim of this study was to develop a novel thermoresponsive material suited for tissue engineering and investigate the growth and harmless detachment of cells cultured on the surface of thermoresponsive tissue culture polystyrene (TCPS). Methods Thermoresponsive N-isopropylacrylamide (NIPAAm) and biocompatible chitosan (CS) were grafted onto the surface of TCPS by ultraviolet (UV)–induced graft polymerization. The chemical composition, surface morphology and thermoresponsiveness of the modified TCPS were investigated by X-ray photoelectron spectroscopy (XPS), atom force microscopy (AFM) and contact angle (CA), respectively. Furthermore, the growth and detachment behaviors of mouse fibroblast cells (L929) on the surface of the modified TCPS were studied by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Results The modified TCPS exhibited good hydrophobic/hydrophilic property alterations in response to temperature. The cytocompatibility of the materials was improved due to the introduction of CS. Cells could be spontaneously detached from the surface without any damage, by controlling environmental temperature. The viability of cells obtained by temperature induction was higher than that obtained by enzymatic digestion. Conclusions This study developed a simple and economical method to fabricate thermoresponsive cell culture dishes and provided new thoughts and experimental bases for exploring novel material applied in tissue engineering.
{"title":"Design and Cytocompatibility of Chitosan-Based Thermoresponsive Cell Culture Plates","authors":"Xiaoling He, Yuxin Zhao, Z. Jin, Yuhan Su, Huiqin An, Lili Ge, Dongsheng Wei, Li Chen","doi":"10.5301/jabfm.5000276","DOIUrl":"https://doi.org/10.5301/jabfm.5000276","url":null,"abstract":"Background The aim of this study was to develop a novel thermoresponsive material suited for tissue engineering and investigate the growth and harmless detachment of cells cultured on the surface of thermoresponsive tissue culture polystyrene (TCPS). Methods Thermoresponsive N-isopropylacrylamide (NIPAAm) and biocompatible chitosan (CS) were grafted onto the surface of TCPS by ultraviolet (UV)–induced graft polymerization. The chemical composition, surface morphology and thermoresponsiveness of the modified TCPS were investigated by X-ray photoelectron spectroscopy (XPS), atom force microscopy (AFM) and contact angle (CA), respectively. Furthermore, the growth and detachment behaviors of mouse fibroblast cells (L929) on the surface of the modified TCPS were studied by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Results The modified TCPS exhibited good hydrophobic/hydrophilic property alterations in response to temperature. The cytocompatibility of the materials was improved due to the introduction of CS. Cells could be spontaneously detached from the surface without any damage, by controlling environmental temperature. The viability of cells obtained by temperature induction was higher than that obtained by enzymatic digestion. Conclusions This study developed a simple and economical method to fabricate thermoresponsive cell culture dishes and provided new thoughts and experimental bases for exploring novel material applied in tissue engineering.","PeriodicalId":51074,"journal":{"name":"Journal of Applied Biomaterials & Biomechanics","volume":"14 1","pages":"404 - 412"},"PeriodicalIF":0.0,"publicationDate":"2016-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5301/jabfm.5000276","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70592812","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}
Background There has been increased attention given to polymeric nanoparticles as protein carriers. In this regard, chitosan/tripolyphosphate (TPP) nanoparticles are considered to be a simple and efficient carrier. However, to have an ideal protein release profile, we need to optimize the properties of the carrier. Methods This study examined the influence of 4 critical process parameters on the physicochemical characteristics of final nanoparticles. Chitosan-based nanoparticles were produced by ionic gelation, and then the size, polydispersity and zeta potential of those resulting nanoparticles were evaluated. Subsequently, the encapsulation efficiency of bovine serum albumin as model protein was investigated. Results The morphologies of nanoparticles were characterized using field emission scanning electron microscopy (FE-SEM). Linear mathematical models were presented for each response through 3 levels using Central Composite Design with the help of design of experiments software, and formulation optimization was performed. Conclusions Such research will serve as a basic study in protein loading into TPP cross-linked chitosan nanoparticles.
{"title":"Statistical Optimization of Chitosan Nanoparticles as Protein Vehicles, Using Response Surface Methodology","authors":"N. Kiaie, R. M. Aghdam, S. H. Tafti, S. H. Emami","doi":"10.5301/jabfm.5000278","DOIUrl":"https://doi.org/10.5301/jabfm.5000278","url":null,"abstract":"Background There has been increased attention given to polymeric nanoparticles as protein carriers. In this regard, chitosan/tripolyphosphate (TPP) nanoparticles are considered to be a simple and efficient carrier. However, to have an ideal protein release profile, we need to optimize the properties of the carrier. Methods This study examined the influence of 4 critical process parameters on the physicochemical characteristics of final nanoparticles. Chitosan-based nanoparticles were produced by ionic gelation, and then the size, polydispersity and zeta potential of those resulting nanoparticles were evaluated. Subsequently, the encapsulation efficiency of bovine serum albumin as model protein was investigated. Results The morphologies of nanoparticles were characterized using field emission scanning electron microscopy (FE-SEM). Linear mathematical models were presented for each response through 3 levels using Central Composite Design with the help of design of experiments software, and formulation optimization was performed. Conclusions Such research will serve as a basic study in protein loading into TPP cross-linked chitosan nanoparticles.","PeriodicalId":51074,"journal":{"name":"Journal of Applied Biomaterials & Biomechanics","volume":"14 1","pages":"413 - 422"},"PeriodicalIF":0.0,"publicationDate":"2016-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5301/jabfm.5000278","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70592371","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}
Background The aim of this work was the development and characterization of a photocatalytic filter for the treatment of indoor air, characterized by a low pressure drop. Methods The filter (photocatalytic filter) was based on a polyester substrate additivated with active carbon (Carbotex 150-6), treated with a sol of titanium dioxide (Sol 121-AB; NextMaterials Ltd.) and illuminated with UV LEDs to induce photocatalytic activity. Results Tests showed that this filter, used in a suitable device for air circulation with a very low noise level, had the ability to block solid particulates, to photocatalytically oxidize a major fraction of volatile organic compounds (VOCs) and deactivate all of the bacteria blocked on the filter, in contrast to traditional commercial air filters on which the bacteria remain viable. Conclusions Activated charcoal filters treated with TiO2 and illuminated by UV LEDs were found to be extremely effective in killing bacteria and effective in decreasing VOC and total suspended particulates (TSP).
{"title":"Development of a Photocatalytic Filter to Control Indoor Air Quality","authors":"B. Del Curto, P. Tarsini, A. Cigada","doi":"10.5301/jabfm.5000336","DOIUrl":"https://doi.org/10.5301/jabfm.5000336","url":null,"abstract":"Background The aim of this work was the development and characterization of a photocatalytic filter for the treatment of indoor air, characterized by a low pressure drop. Methods The filter (photocatalytic filter) was based on a polyester substrate additivated with active carbon (Carbotex 150-6), treated with a sol of titanium dioxide (Sol 121-AB; NextMaterials Ltd.) and illuminated with UV LEDs to induce photocatalytic activity. Results Tests showed that this filter, used in a suitable device for air circulation with a very low noise level, had the ability to block solid particulates, to photocatalytically oxidize a major fraction of volatile organic compounds (VOCs) and deactivate all of the bacteria blocked on the filter, in contrast to traditional commercial air filters on which the bacteria remain viable. Conclusions Activated charcoal filters treated with TiO2 and illuminated by UV LEDs were found to be extremely effective in killing bacteria and effective in decreasing VOC and total suspended particulates (TSP).","PeriodicalId":51074,"journal":{"name":"Journal of Applied Biomaterials & Biomechanics","volume":"104 1","pages":"496 - 501"},"PeriodicalIF":0.0,"publicationDate":"2016-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5301/jabfm.5000336","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70593240","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}
Background This work presents a sustainable approach for the stabilization of polylactic acid (PLA) against thermo-oxidative aging. Methods Naturally occurring phenolic and polyphenolic compounds, such as ferulic acid (FerAc), vanillic acid (VanAc), quercetin (Querc) and vitamin E (VitE), were introduced into PLA. Results The preliminary characterization of the systems formulated containing different amounts of natural stabilizers showed that all compounds used acted as plasticizers, leading to a decrease in rheological functions with respect to neat PLA, without significantly modifying the crystallinity of the raw material. The study of the thermo-oxidative behavior of neat PLA and PLA/natural compound systems, performed by spectrometric and thermal analyses, indicated that all stabilizers considered were able to exert a remarkable antioxidant action against thermo-oxidative phenomena. Conclusions All natural compounds considered are thus proposed as ecofriendly stabilizers, to get fully bio-based polymer systems with enhanced thermo-oxidative stability, suitable for biomedical applications.
{"title":"Biopolyester-Based Systems Containing Naturally Occurring Compounds with Enhanced Thermo-Oxidative Stability","authors":"R. Arrigo, E. Morici, N. T. Dintcheva","doi":"10.5301/jabfm.5000322","DOIUrl":"https://doi.org/10.5301/jabfm.5000322","url":null,"abstract":"Background This work presents a sustainable approach for the stabilization of polylactic acid (PLA) against thermo-oxidative aging. Methods Naturally occurring phenolic and polyphenolic compounds, such as ferulic acid (FerAc), vanillic acid (VanAc), quercetin (Querc) and vitamin E (VitE), were introduced into PLA. Results The preliminary characterization of the systems formulated containing different amounts of natural stabilizers showed that all compounds used acted as plasticizers, leading to a decrease in rheological functions with respect to neat PLA, without significantly modifying the crystallinity of the raw material. The study of the thermo-oxidative behavior of neat PLA and PLA/natural compound systems, performed by spectrometric and thermal analyses, indicated that all stabilizers considered were able to exert a remarkable antioxidant action against thermo-oxidative phenomena. Conclusions All natural compounds considered are thus proposed as ecofriendly stabilizers, to get fully bio-based polymer systems with enhanced thermo-oxidative stability, suitable for biomedical applications.","PeriodicalId":51074,"journal":{"name":"Journal of Applied Biomaterials & Biomechanics","volume":"14 1","pages":"455 - 462"},"PeriodicalIF":0.0,"publicationDate":"2016-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5301/jabfm.5000322","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70592560","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}
N. Harrasser, M. de Wild, Johannes Gorkotte, A. Obermeier, S. Feihl, M. Straub, R. von Eisenhart-Rothe, H. Gollwitzer, Jasmine Rüegg, W. Moser, P. Gruner, R. Burgkart
Background Silver ions (Ag+) have strong antibacterial effects, and silver-coated materials are in widespread clinical use. However, the application of silver-coated medical devices is not without concerns: its use with direct bone contact is not established, and systemic toxic side effects of released Ag+ have been described. Therefore, alternative bactericidal coatings with a more localized way of acting – e.g., calcium dihydroxide, Ca(OH)2 (CH) – would be advantageous. Methods A new rat model of the animal's tibial metaphysis was developed. In the left proximal tibiae of 36 male Wistar rats, titanium screws were implanted. The screws were coated with hydroxyapatite (HA; 12 animals: group I), low-dosed HA silver (HA-Ag; 12 animals: group II) and CH (12 animals: group III). After 6 weeks, all rats were sacrificed. The implants were evaluated for morphological changes on their surfaces, by light microscopy, scanning electron microscopy and energy-dispersive X-ray spectroscopy; for osteointegration, by measurement of resistance to removal; and for bacterial colonization, by quantitative culture analysis. Additionally, the tibial bone was investigated histologically for signs of osteomyelitis and sonicated to detect bacterial loads. Results (i) No microbiological or histological signs of infection could be determined on any of the screws or the surrounding bone. (ii) The bone-implant interface analysis revealed extensive bone formation and direct bone-implant contact on all HA, HA-Ag and HA-CH coated screws. (iii) HA and HA-Ag were partially, and CH was fully, degraded on the screw coating, allowing host bone to osteointegrate.
{"title":"Evaluation of Calcium Dihydroxide- and Silver-Coated Implants in the Rat Tibia","authors":"N. Harrasser, M. de Wild, Johannes Gorkotte, A. Obermeier, S. Feihl, M. Straub, R. von Eisenhart-Rothe, H. Gollwitzer, Jasmine Rüegg, W. Moser, P. Gruner, R. Burgkart","doi":"10.5301/jabfm.5000323","DOIUrl":"https://doi.org/10.5301/jabfm.5000323","url":null,"abstract":"Background Silver ions (Ag+) have strong antibacterial effects, and silver-coated materials are in widespread clinical use. However, the application of silver-coated medical devices is not without concerns: its use with direct bone contact is not established, and systemic toxic side effects of released Ag+ have been described. Therefore, alternative bactericidal coatings with a more localized way of acting – e.g., calcium dihydroxide, Ca(OH)2 (CH) – would be advantageous. Methods A new rat model of the animal's tibial metaphysis was developed. In the left proximal tibiae of 36 male Wistar rats, titanium screws were implanted. The screws were coated with hydroxyapatite (HA; 12 animals: group I), low-dosed HA silver (HA-Ag; 12 animals: group II) and CH (12 animals: group III). After 6 weeks, all rats were sacrificed. The implants were evaluated for morphological changes on their surfaces, by light microscopy, scanning electron microscopy and energy-dispersive X-ray spectroscopy; for osteointegration, by measurement of resistance to removal; and for bacterial colonization, by quantitative culture analysis. Additionally, the tibial bone was investigated histologically for signs of osteomyelitis and sonicated to detect bacterial loads. Results (i) No microbiological or histological signs of infection could be determined on any of the screws or the surrounding bone. (ii) The bone-implant interface analysis revealed extensive bone formation and direct bone-implant contact on all HA, HA-Ag and HA-CH coated screws. (iii) HA and HA-Ag were partially, and CH was fully, degraded on the screw coating, allowing host bone to osteointegrate.","PeriodicalId":51074,"journal":{"name":"Journal of Applied Biomaterials & Biomechanics","volume":"14 1","pages":"441 - 448"},"PeriodicalIF":0.0,"publicationDate":"2016-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5301/jabfm.5000323","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70592697","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}
Background Wear associated with hip components represents the main clinical problem in these patients, and it is important to develop new techniques for more accurate measurements of that wear. Currently, the gravimetric method is the gold standard for assessing mass measurements in preclinical evaluations. However, this method does not give other information such as volumetric loss or surface deviation. This work aimed to develop and validate a new technique to quantify ceramic volume loss from in vitro experiments using micro-computed tomography (micro-CT). Methods An alumina (BIOLOX® forte) femoral head (Ø = 28 mm) was used. Mass and volume loss were approached by gravimetric method (using a four decimal place digital microbalance) and by using Skyscan 1176 microtomographic system, respectively. Results Standard error and coefficient of variance of both gravimetric and experimental groups demonstrated the reliability of the micro-CT analysis technique. Conclusions In conclusion, the findings of the present study suggest that this new protocol could be considered an important tool for wear assessment and that we have found a reliable metrological protocol for volumetric analysis of ceramic femoral head prostheses, demonstrating that the micro-CT technique can be an important tool for wear assessment.
{"title":"Is Micro-Computed Tomography Useful for Wear Assessment of Ceramic Femoral Heads? A Preliminary Evaluation of Volume Measurements","authors":"A. Parrilli, S. Falcioni, M. Fini, S. Affatato","doi":"10.5301/jabfm.5000324","DOIUrl":"https://doi.org/10.5301/jabfm.5000324","url":null,"abstract":"Background Wear associated with hip components represents the main clinical problem in these patients, and it is important to develop new techniques for more accurate measurements of that wear. Currently, the gravimetric method is the gold standard for assessing mass measurements in preclinical evaluations. However, this method does not give other information such as volumetric loss or surface deviation. This work aimed to develop and validate a new technique to quantify ceramic volume loss from in vitro experiments using micro-computed tomography (micro-CT). Methods An alumina (BIOLOX® forte) femoral head (Ø = 28 mm) was used. Mass and volume loss were approached by gravimetric method (using a four decimal place digital microbalance) and by using Skyscan 1176 microtomographic system, respectively. Results Standard error and coefficient of variance of both gravimetric and experimental groups demonstrated the reliability of the micro-CT analysis technique. Conclusions In conclusion, the findings of the present study suggest that this new protocol could be considered an important tool for wear assessment and that we have found a reliable metrological protocol for volumetric analysis of ceramic femoral head prostheses, demonstrating that the micro-CT technique can be an important tool for wear assessment.","PeriodicalId":51074,"journal":{"name":"Journal of Applied Biomaterials & Biomechanics","volume":"14 1","pages":"483 - 489"},"PeriodicalIF":0.0,"publicationDate":"2016-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5301/jabfm.5000324","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70592865","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}
B. Del Curto, N. Barelli, Mauro Profaizer, S. Faré, M. Tanzi, A. Cigada, G. Ognibene, G. Recca, G. Cicala
Background Until now, environmental sustainability issues are almost entirely unsolved for packaging materials. With the final aim of finding materials with a single recycling channel, cellulose fiber/poly(vinyl)alcohol composites were investigated. Methods After extrusion and injection molding, samples of composite with different cellulose fiber content (30%, 50% and 70% w/w) were tested. Results Tensile mechanical tests exhibited an improvement in composite stiffness when the reinforcement content was increased together with a decrease in composite elongation. Solubility tests performed at room temperature and 45°C showed different behavior depending on the water-resistant film applied on the composite (50% cellulose fiber content). In particular, the uncoated composite showed complete solubility after 2 hours, whereas at the same time point, no solubility occurred when a non-water-soluble varnish was used. Conclusions The proposed composites, named Poly-paper, appear to warrant further investigation as highly sustainable packaging.
{"title":"Poly-Paper: A Sustainable Material for Packaging, Based on Recycled Paper and Recyclable with Paper","authors":"B. Del Curto, N. Barelli, Mauro Profaizer, S. Faré, M. Tanzi, A. Cigada, G. Ognibene, G. Recca, G. Cicala","doi":"10.5301/jabfm.5000335","DOIUrl":"https://doi.org/10.5301/jabfm.5000335","url":null,"abstract":"Background Until now, environmental sustainability issues are almost entirely unsolved for packaging materials. With the final aim of finding materials with a single recycling channel, cellulose fiber/poly(vinyl)alcohol composites were investigated. Methods After extrusion and injection molding, samples of composite with different cellulose fiber content (30%, 50% and 70% w/w) were tested. Results Tensile mechanical tests exhibited an improvement in composite stiffness when the reinforcement content was increased together with a decrease in composite elongation. Solubility tests performed at room temperature and 45°C showed different behavior depending on the water-resistant film applied on the composite (50% cellulose fiber content). In particular, the uncoated composite showed complete solubility after 2 hours, whereas at the same time point, no solubility occurred when a non-water-soluble varnish was used. Conclusions The proposed composites, named Poly-paper, appear to warrant further investigation as highly sustainable packaging.","PeriodicalId":51074,"journal":{"name":"Journal of Applied Biomaterials & Biomechanics","volume":"14 1","pages":"490 - 495"},"PeriodicalIF":0.0,"publicationDate":"2016-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5301/jabfm.5000335","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70593171","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：