Pub Date : 2019-10-01DOI: 10.1177/2280800019882645
O. Ozyilmaz, F. Aykent, Gulsum Sayin Ozel
Introduction: The aim of this study was to evaluate the effect of different heights of attachment and mucosa thicknesses on the stress distribution of two implant-retained mandibular overdenture designs under loading using the photoelastic stress analysis method. Materials and methods: Six photoelastic models of an edentulous mandibula were fabricated with two solitary implants that were placed in the canine regions. The attachment systems studied were ball and locator stud attachments. Both the ball and locator groups included three models that had different residual ridge heights so as to provide different mucosa thicknesses (1 mm–1 mm, 1 mm–2 mm, 1 mm–4 mm). A static vertical force of 135 N was applied unilaterally (each on the right then the left side) to the central fossa of the first molars. Models were positioned in the field of a circular polariscope to observe the distribution of isochromatic fringes around the implants and the interimplant areas under loading. The photoelastic stress fringes were monitored and recorded photographically. Results: The ball attachment groups showed higher stress values than did the locator groups under loading. Both attachment systems produced the lowest stress values in stimulated 1 mm–1 mm mucosa thickness models. The models with 1 mm–2 mm mucosa thicknesses showed higher stress values than did other models for both attachment systems. The highest stress value observed around both attachment systems was the moderate level in all test models. Conclusion: In different height mucosa thicknesses, locator attachment models distributed the load to the other side of the implant and its surrounding tissue, whereas the ball attachment did not. Regardless of mucosal thickness and attachment type, the implant on the loading side was subjected to the highest stress concentration.
摘要:本研究采用光弹性应力分析方法，评价不同附着体高度和黏膜厚度对两种种植体下颌覆盖义齿在载荷作用下应力分布的影响。材料与方法:采用两颗单体种植体植入犬齿区，制作了6个无牙下颌光弹性模型。所研究的附件系统为滚珠和定位螺柱附件。球组和定位器组均包括三种模型，这些模型具有不同的残余脊高，从而提供不同的粘膜厚度(1 mm - 1 mm, 1 mm - 2 mm, 1 mm - 4 mm)。在第一磨牙中央窝单侧施加135牛的静态垂直力(分别在右侧和左侧)。将模型放置在圆形偏光镜视野中，观察载荷作用下植入体周围和植入体间等色条纹的分布。光弹性应力条纹的监测和照相记录。结果:在载荷作用下，球附着组的应力值高于定位器组。在受刺激的1 mm - 1 mm粘膜厚度模型中，两种附着系统产生的应力值最低。两种附着系统中，厚度为1 mm ~ 2 mm的模型均表现出较高的应力值。在所有测试模型中，两种依恋系统的最高应力值均为中等水平。结论:在不同高度粘膜厚度下，定位器附着体模型将载荷分配到种植体的另一侧及其周围组织，而球附着体则没有。无论粘膜厚度和附着类型如何，加载侧种植体承受的应力浓度最高。
{"title":"Effect of mucosa thicknesses on stress distribution of implant-supported overdentures under unilateral loading: Photoelastic analysis","authors":"O. Ozyilmaz, F. Aykent, Gulsum Sayin Ozel","doi":"10.1177/2280800019882645","DOIUrl":"https://doi.org/10.1177/2280800019882645","url":null,"abstract":"Introduction: The aim of this study was to evaluate the effect of different heights of attachment and mucosa thicknesses on the stress distribution of two implant-retained mandibular overdenture designs under loading using the photoelastic stress analysis method. Materials and methods: Six photoelastic models of an edentulous mandibula were fabricated with two solitary implants that were placed in the canine regions. The attachment systems studied were ball and locator stud attachments. Both the ball and locator groups included three models that had different residual ridge heights so as to provide different mucosa thicknesses (1 mm–1 mm, 1 mm–2 mm, 1 mm–4 mm). A static vertical force of 135 N was applied unilaterally (each on the right then the left side) to the central fossa of the first molars. Models were positioned in the field of a circular polariscope to observe the distribution of isochromatic fringes around the implants and the interimplant areas under loading. The photoelastic stress fringes were monitored and recorded photographically. Results: The ball attachment groups showed higher stress values than did the locator groups under loading. Both attachment systems produced the lowest stress values in stimulated 1 mm–1 mm mucosa thickness models. The models with 1 mm–2 mm mucosa thicknesses showed higher stress values than did other models for both attachment systems. The highest stress value observed around both attachment systems was the moderate level in all test models. Conclusion: In different height mucosa thicknesses, locator attachment models distributed the load to the other side of the implant and its surrounding tissue, whereas the ball attachment did not. Regardless of mucosal thickness and attachment type, the implant on the loading side was subjected to the highest stress concentration.","PeriodicalId":51074,"journal":{"name":"Journal of Applied Biomaterials & Biomechanics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/2280800019882645","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46378215","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}
Pub Date : 2019-07-01DOI: 10.1177/2280800019847067
S. Choi, Y. Jang, Jong-Hwa Jang, T. Bae, Sook-Jeong Lee, Min-Ho Lee
Background: Biofilm formation and microbial colonization on the surface of implant devices may cause dental caries and peri-implantitis. Therefore, various surface treatments have been developed to improve the antibacterial activity of titanium implant. Methods: Silver-loaded polydopamine coating was formed by immersing pure titanium in dopamine hydrochloride/HCl buffer solution for 24 h in 50 mL silver nitrate solutions with different concentrations for 30 min. Microbial growth inhibition and microbial growth curve analyses for bacterial solutions of Streptococcus mutans and Porphyromonas gingivalis incubated with the specimens were respectively conducted by counting the numbers of colonies on agar solid medium and by measuring absorbance using enzyme-linked immunosorbent assay reader. Results: Silver nanoparticles were uniformly distributed over the whole surface of the polydopamine and silver-coated titanium specimens. The numbers of microbial colonies for both bacteria cultured with surface-modified titanium were significantly lower than those cultured with uncoated titanium. When Streptococcus mutans and Porphyromonas gingivalis were cultured with surface-modified titanium, the lag phase of the growth curves for both bacteria was continually maintained, whereas the lag phase for Streptococcus mutans and Porphyromonas gingivalis changed to exponential phase after 9 and 15 h, respectively, when both bacteria were cultured with uncoated titanium. Conclusion: It was confirmed that the coating of polydopamine and silver on the surface of titanium effectively retards the microbial growth, which can cause the formation of biofilm and pathogenesis of gum disease in the mouth.
{"title":"Enhanced antibacterial activity of titanium by surface modification with polydopamine and silver for dental implant application","authors":"S. Choi, Y. Jang, Jong-Hwa Jang, T. Bae, Sook-Jeong Lee, Min-Ho Lee","doi":"10.1177/2280800019847067","DOIUrl":"https://doi.org/10.1177/2280800019847067","url":null,"abstract":"Background: Biofilm formation and microbial colonization on the surface of implant devices may cause dental caries and peri-implantitis. Therefore, various surface treatments have been developed to improve the antibacterial activity of titanium implant. Methods: Silver-loaded polydopamine coating was formed by immersing pure titanium in dopamine hydrochloride/HCl buffer solution for 24 h in 50 mL silver nitrate solutions with different concentrations for 30 min. Microbial growth inhibition and microbial growth curve analyses for bacterial solutions of Streptococcus mutans and Porphyromonas gingivalis incubated with the specimens were respectively conducted by counting the numbers of colonies on agar solid medium and by measuring absorbance using enzyme-linked immunosorbent assay reader. Results: Silver nanoparticles were uniformly distributed over the whole surface of the polydopamine and silver-coated titanium specimens. The numbers of microbial colonies for both bacteria cultured with surface-modified titanium were significantly lower than those cultured with uncoated titanium. When Streptococcus mutans and Porphyromonas gingivalis were cultured with surface-modified titanium, the lag phase of the growth curves for both bacteria was continually maintained, whereas the lag phase for Streptococcus mutans and Porphyromonas gingivalis changed to exponential phase after 9 and 15 h, respectively, when both bacteria were cultured with uncoated titanium. Conclusion: It was confirmed that the coating of polydopamine and silver on the surface of titanium effectively retards the microbial growth, which can cause the formation of biofilm and pathogenesis of gum disease in the mouth.","PeriodicalId":51074,"journal":{"name":"Journal of Applied Biomaterials & Biomechanics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/2280800019847067","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46709162","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}
Pub Date : 2019-07-01DOI: 10.1177/2280800019851771
J. Loyola-Rodríguez, Fernando Torres-Méndez, L. F. Espinosa-Cristóbal, J. García-Cortés, Alejandra Loyola-Leyva, F. J. González, Uriel Soto-Barreras, R. Nieto-Aguilar, G. Contreras-Palma
Background: The main microorganism associated with the failure of endodontic treatments is Enterococcus faecalis. Although several endodontic therapeutics have demonstrated antimicrobial activity against E. faecalis, the antimicrobial effectiveness of chitosan (CsNPs) and silver nanoparticles (AgNPs) included into conventional endodontic sealers for endodontic therapies is still unclear. Aim: The objective of this study was to evaluate the antibacterial activity increment (AAI) of endodontic sealers containing CsNPs and AgNPs as well as some chemical components against E. faecalis by direct contact assays. Methods: CsNPs and AgNPs were synthesized by reduction and ionic gelation methods, respectively. Nanoparticles were characterized by dynamic light scattering and energy dispersive X-ray analysis. The bactericidal activity was tested on monolayers on agar plates and collagen membrane surface assays against E. faecalis. Results: The size of CsNPs was 70.6±14.8 nm and zeta potential was 52.0±5.4 mV; the size of AgNPs was 54.2±8.5 nm, and zeta potential was –48.4±6.9 mV. All materials, single or combined, showed an AAI, especially when CsNPs, chlorhexidine (Chx), and the combination of CsNPs-Chx were added. However, the combination of CsNPs-Chx showed the highest (55%) AAI, followed by Chx (35.5%) and CsNPs (11.1%), respectively. There was a significant statistical difference in all comparisons (p < 0.05). Tubliseal (40%) and AH Plus (32%) sealants showed a higher AAI on E. faecalis in the monolayer test and collagen membrane assay analyzed by scanning electron microscopy. Conclusions: Tubliseal and AH plus sealers combined with nanoparticles, especially CsNPs-Chx, could be used for conventional endodontic treatments in the control of E. faecalis bacteria.
{"title":"Antimicrobial activity of endodontic sealers and medications containing chitosan and silver nanoparticles against Enterococcus faecalis","authors":"J. Loyola-Rodríguez, Fernando Torres-Méndez, L. F. Espinosa-Cristóbal, J. García-Cortés, Alejandra Loyola-Leyva, F. J. González, Uriel Soto-Barreras, R. Nieto-Aguilar, G. Contreras-Palma","doi":"10.1177/2280800019851771","DOIUrl":"https://doi.org/10.1177/2280800019851771","url":null,"abstract":"Background: The main microorganism associated with the failure of endodontic treatments is Enterococcus faecalis. Although several endodontic therapeutics have demonstrated antimicrobial activity against E. faecalis, the antimicrobial effectiveness of chitosan (CsNPs) and silver nanoparticles (AgNPs) included into conventional endodontic sealers for endodontic therapies is still unclear. Aim: The objective of this study was to evaluate the antibacterial activity increment (AAI) of endodontic sealers containing CsNPs and AgNPs as well as some chemical components against E. faecalis by direct contact assays. Methods: CsNPs and AgNPs were synthesized by reduction and ionic gelation methods, respectively. Nanoparticles were characterized by dynamic light scattering and energy dispersive X-ray analysis. The bactericidal activity was tested on monolayers on agar plates and collagen membrane surface assays against E. faecalis. Results: The size of CsNPs was 70.6±14.8 nm and zeta potential was 52.0±5.4 mV; the size of AgNPs was 54.2±8.5 nm, and zeta potential was –48.4±6.9 mV. All materials, single or combined, showed an AAI, especially when CsNPs, chlorhexidine (Chx), and the combination of CsNPs-Chx were added. However, the combination of CsNPs-Chx showed the highest (55%) AAI, followed by Chx (35.5%) and CsNPs (11.1%), respectively. There was a significant statistical difference in all comparisons (p < 0.05). Tubliseal (40%) and AH Plus (32%) sealants showed a higher AAI on E. faecalis in the monolayer test and collagen membrane assay analyzed by scanning electron microscopy. Conclusions: Tubliseal and AH plus sealers combined with nanoparticles, especially CsNPs-Chx, could be used for conventional endodontic treatments in the control of E. faecalis bacteria.","PeriodicalId":51074,"journal":{"name":"Journal of Applied Biomaterials & Biomechanics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/2280800019851771","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44220088","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}
Pub Date : 2019-07-01DOI: 10.1177/2280800019867075
C. Guarise, Carlo Barbera, M. Pavan, S. Panfilo, R. Beninatto, D. Galesso
The success of hyaluronic acid (HA)-based dermal fillers, with more than 2 million minimally invasive procedures conducted in 2016 in the US alone, is due to their hygroscopic properties of biocompatibility and reversibility. The type and density of HA cross-linkage, as well as the manufacturing technology, may influence not only the in vivo persistence but also the safety profile of dermal fillers. 1,4-Butanediol diglycidyl ether (BDDE) is the cross-linker used in most market-leading HA fillers; 1,4-butanediol di-(propan-2,3-diolyl) ether (BDPE) is the major impurity obtained from the HA–BDDE cross-linking (HBC) process. In this work, a new process to obtain high purity HBC fillers was developed. A new HPLC-MS method was validated for the quantification of BDPE content in HBC dermal fillers. In vitro cytotoxicity of BDPE was evaluated in fibroblasts (IC50 = 0.48 mg/mL). The viscoelasticity was monitored during the shelf-life of the HBC-10% hydrogel and was correlated with in vitro hyaluronidase resistance and in vivo residence time in a rabbit model. This analysis showed that elasticity is the best parameter to predict the in vivo residence time. Finally, a series of parameters were investigated in certain marketed dermal fillers and were compared with the results of the HBC-10% hydrogel.
{"title":"HA-based dermal filler: downstream process comparison, impurity quantitation by validated HPLC-MS analysis, and in vivo residence time study","authors":"C. Guarise, Carlo Barbera, M. Pavan, S. Panfilo, R. Beninatto, D. Galesso","doi":"10.1177/2280800019867075","DOIUrl":"https://doi.org/10.1177/2280800019867075","url":null,"abstract":"The success of hyaluronic acid (HA)-based dermal fillers, with more than 2 million minimally invasive procedures conducted in 2016 in the US alone, is due to their hygroscopic properties of biocompatibility and reversibility. The type and density of HA cross-linkage, as well as the manufacturing technology, may influence not only the in vivo persistence but also the safety profile of dermal fillers. 1,4-Butanediol diglycidyl ether (BDDE) is the cross-linker used in most market-leading HA fillers; 1,4-butanediol di-(propan-2,3-diolyl) ether (BDPE) is the major impurity obtained from the HA–BDDE cross-linking (HBC) process. In this work, a new process to obtain high purity HBC fillers was developed. A new HPLC-MS method was validated for the quantification of BDPE content in HBC dermal fillers. In vitro cytotoxicity of BDPE was evaluated in fibroblasts (IC50 = 0.48 mg/mL). The viscoelasticity was monitored during the shelf-life of the HBC-10% hydrogel and was correlated with in vitro hyaluronidase resistance and in vivo residence time in a rabbit model. This analysis showed that elasticity is the best parameter to predict the in vivo residence time. Finally, a series of parameters were investigated in certain marketed dermal fillers and were compared with the results of the HBC-10% hydrogel.","PeriodicalId":51074,"journal":{"name":"Journal of Applied Biomaterials & Biomechanics","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/2280800019867075","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42978407","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}
Pub Date : 2019-04-01DOI: 10.1177/2280800019833561
K. Uma, Yi‐Ru Lee, Gung-Tin Pan, T. C. Yang
Background: Due to the outstanding properties of graphene, researchers are considering it a good candidate for thin film encapsulation on polymer substrates. In this work, we produce a UV-cured resin prepared by an inexpensive solution technique for the encapsulation of graphene oxide (GO), mechanical exfoliation graphene (mG), reduced graphene oxide (rGO), graphite, and SiO2 nanofillers on the surface of a PET film for employment as an impermeable film. Methods: The water vapor transmission rate (WVTR) is measured for the UV-cured encapsulated nanofillers on PET films. Results: The WVTR was reduced to <10−2 g m−2/day for GO and rGO nanofillers with a thickness of 1 mm. Pencil scratch hardness tests performed on the encapsulated nanofillers deposited on the PET film showed them to be stable up to 5H–8H and the glass transition temperature results for the GO, mG, and rGO nanofillers on PET remained steady up to 180°C. Conclusions: The prepared UV-cured resin encapsulated graphene nanofillers coated on the polymer substrate by a simple solution method was shown to have good impermeability to water vapor.
背景：由于石墨烯的优异性能，研究人员认为它是在聚合物基底上进行薄膜封装的良好候选者。在这项工作中，我们生产了一种紫外线固化树脂，该树脂通过一种廉价的溶液技术制备，用于在PET膜表面封装氧化石墨烯（GO）、机械剥离石墨烯（mG）、还原石墨烯（rGO）、石墨和SiO2纳米填料，用作不渗透膜。方法：测定紫外光固化PET薄膜上包封纳米填料的水蒸气透过率。结果：厚度为1 mm的GO和rGO纳米填料的WVTR降低至<10−2 g m−2/天。对沉积在PET膜上的封装纳米填料进行的铅笔划痕硬度测试表明，它们在5H–8H下保持稳定，PET上GO、mG和rGO纳米填料的玻璃化转变温度结果在180°C下保持稳定。结论：采用简单溶液法在聚合物基体上制备的紫外光固化树脂包封石墨烯纳米填料具有良好的抗水蒸气性能。
{"title":"Facile preparation of UV-cured polymer sealants encapsulated graphene nanofillers and evaluation of their water vapor permeability","authors":"K. Uma, Yi‐Ru Lee, Gung-Tin Pan, T. C. Yang","doi":"10.1177/2280800019833561","DOIUrl":"https://doi.org/10.1177/2280800019833561","url":null,"abstract":"Background: Due to the outstanding properties of graphene, researchers are considering it a good candidate for thin film encapsulation on polymer substrates. In this work, we produce a UV-cured resin prepared by an inexpensive solution technique for the encapsulation of graphene oxide (GO), mechanical exfoliation graphene (mG), reduced graphene oxide (rGO), graphite, and SiO2 nanofillers on the surface of a PET film for employment as an impermeable film. Methods: The water vapor transmission rate (WVTR) is measured for the UV-cured encapsulated nanofillers on PET films. Results: The WVTR was reduced to <10−2 g m−2/day for GO and rGO nanofillers with a thickness of 1 mm. Pencil scratch hardness tests performed on the encapsulated nanofillers deposited on the PET film showed them to be stable up to 5H–8H and the glass transition temperature results for the GO, mG, and rGO nanofillers on PET remained steady up to 180°C. Conclusions: The prepared UV-cured resin encapsulated graphene nanofillers coated on the polymer substrate by a simple solution method was shown to have good impermeability to water vapor.","PeriodicalId":51074,"journal":{"name":"Journal of Applied Biomaterials & Biomechanics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46696398","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}
Pub Date : 2019-04-01DOI: 10.1177/2280800019857064
Mingying Tang, Yangjun Yan, Jianan Ouyang, Kun Yu, Congcong Liu, Xiaohua Zhou, Zhenting Wang, Youwen Deng, C. Shuai
Background: Rapid corrosion rates are a major impediment to the use of magnesium alloys in bone tissue engineering despite their good mechanical properties and biodegradability. Zinc is a promising alloy element, and it is an effective grain refiner for magnesium. β-Ca3(PO4)2 (β-TCP) is widely used for bone regeneration because of its good biocompatibility, and it also has a similar chemical and crystal structure to human bone. Methods: In this research, the magnesium alloy was reinforced by adding 3%Zn (wt.%) and 5%β-TCP (wt.%) particles in order to improve the corrosion resistance and biocompatibility. Furthermore, the biomaterial was prepared through powder metallurgy technology using NH4HCO3 as space-holding particles to construct porous Mg–3%Zn/5%β-TCP scaffolds. Results: The results revealed that the magnesium-zinc phase and calcium phosphate phase were uniformly distributed in the α-magnesium matrix. Mechanical and corrosion tests indicated that the scaffolds had mechanical strengths similar to that of human bone, and their corrosion resistance decreased with an increase in the porosity. The scaffolds had cytotoxicity grades of 0–1 against MG63 cells, SaoS2 cells, and HK-2 cells, which suggested that they were appropriate for cellular applications. In addition, the scaffolds demonstrated excellent biocompatibility when tested in rabbits. Conclusions: These results indicate that porous Mg–3%Zn/5%β-TCP scaffolds are promising biodegradable implants for bone tissue engineering.
{"title":"Research on corrosion behavior and biocompatibility of a porous Mg–3%Zn/5%β-Ca3(PO4)2 composite scaffold for bone tissue engineering","authors":"Mingying Tang, Yangjun Yan, Jianan Ouyang, Kun Yu, Congcong Liu, Xiaohua Zhou, Zhenting Wang, Youwen Deng, C. Shuai","doi":"10.1177/2280800019857064","DOIUrl":"https://doi.org/10.1177/2280800019857064","url":null,"abstract":"Background: Rapid corrosion rates are a major impediment to the use of magnesium alloys in bone tissue engineering despite their good mechanical properties and biodegradability. Zinc is a promising alloy element, and it is an effective grain refiner for magnesium. β-Ca3(PO4)2 (β-TCP) is widely used for bone regeneration because of its good biocompatibility, and it also has a similar chemical and crystal structure to human bone. Methods: In this research, the magnesium alloy was reinforced by adding 3%Zn (wt.%) and 5%β-TCP (wt.%) particles in order to improve the corrosion resistance and biocompatibility. Furthermore, the biomaterial was prepared through powder metallurgy technology using NH4HCO3 as space-holding particles to construct porous Mg–3%Zn/5%β-TCP scaffolds. Results: The results revealed that the magnesium-zinc phase and calcium phosphate phase were uniformly distributed in the α-magnesium matrix. Mechanical and corrosion tests indicated that the scaffolds had mechanical strengths similar to that of human bone, and their corrosion resistance decreased with an increase in the porosity. The scaffolds had cytotoxicity grades of 0–1 against MG63 cells, SaoS2 cells, and HK-2 cells, which suggested that they were appropriate for cellular applications. In addition, the scaffolds demonstrated excellent biocompatibility when tested in rabbits. Conclusions: These results indicate that porous Mg–3%Zn/5%β-TCP scaffolds are promising biodegradable implants for bone tissue engineering.","PeriodicalId":51074,"journal":{"name":"Journal of Applied Biomaterials & Biomechanics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/2280800019857064","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44810611","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}
Pub Date : 2019-04-01DOI: 10.1177/2280800019863637
I. Gibson, A. Momeni, M. Filiaggi
Background: Periodontitis is an inflammatory disease with a bacterial etiology that affects the supporting structures of the teeth and is a major cause of tooth loss. The objective of this study was to investigate the drug loading and in vitro release of minocycline from novel calcium polyphosphate microspheres intended for use in treating periodontitis. Methods: Calcium polyphosphate coacervate, produced by a precipitation reaction of calcium chloride and sodium polyphosphate solutions, was loaded with minocycline and subsequently used to produce microspheres by an emulsion/solvent extraction technique. Microspheres classified by size were subjected to a 7-day elution in a Tris-buffer solution under dynamic conditions. The physicochemical characteristics of the drug-loaded microspheres were investigated using scanning electron microscopy, particle size analysis, Phosphorus-31 Nuclear Magnetic Resonance spectroscopy, and Inductively Coupled Plasma Optical Emission Spectroscopy. Drug loading and release were determined using ultraviolet -visible (UV/VIS) spectrophotometry. Results: Minocycline-loaded calcium polyphosphate microspheres of varying size were successfully produced, with small and large microspheres having volume mean diameters of 22 ± 1 µm and 193 ± 5 µm, respectively. Polyphosphate chain length and calcium to phosphorus mole ratio remained stable throughout microsphere production. Drug loading was 1.64 ± 0.16, 1.35 ± 0.55, and 0.84 ± 0.14 weight% for the coacervate and large and small microspheres, respectively, corresponding to mean encapsulation efficiencies of 81.7 ± 12.2 % and 50.9 ± 3.9 % for the large and small microspheres. Sustained drug release was observed in vitro over a clinically relevant 7-day period, with small and large microspheres exhibiting similar elution profiles. Antibiotic release generally followed microsphere degradation as measured by Ca and P ion release. Conclusions: This study demonstrated successful drug loading of calcium polyphosphate microspheres with minocycline. Furthermore, in vitro sustained release of minocycline over a 7-day period was observed, suggesting potential utility of this approach for treating periodontitis.
{"title":"Minocycline-loaded calcium polyphosphate glass microspheres as a potential drug-delivery agent for the treatment of periodontitis","authors":"I. Gibson, A. Momeni, M. Filiaggi","doi":"10.1177/2280800019863637","DOIUrl":"https://doi.org/10.1177/2280800019863637","url":null,"abstract":"Background: Periodontitis is an inflammatory disease with a bacterial etiology that affects the supporting structures of the teeth and is a major cause of tooth loss. The objective of this study was to investigate the drug loading and in vitro release of minocycline from novel calcium polyphosphate microspheres intended for use in treating periodontitis. Methods: Calcium polyphosphate coacervate, produced by a precipitation reaction of calcium chloride and sodium polyphosphate solutions, was loaded with minocycline and subsequently used to produce microspheres by an emulsion/solvent extraction technique. Microspheres classified by size were subjected to a 7-day elution in a Tris-buffer solution under dynamic conditions. The physicochemical characteristics of the drug-loaded microspheres were investigated using scanning electron microscopy, particle size analysis, Phosphorus-31 Nuclear Magnetic Resonance spectroscopy, and Inductively Coupled Plasma Optical Emission Spectroscopy. Drug loading and release were determined using ultraviolet -visible (UV/VIS) spectrophotometry. Results: Minocycline-loaded calcium polyphosphate microspheres of varying size were successfully produced, with small and large microspheres having volume mean diameters of 22 ± 1 µm and 193 ± 5 µm, respectively. Polyphosphate chain length and calcium to phosphorus mole ratio remained stable throughout microsphere production. Drug loading was 1.64 ± 0.16, 1.35 ± 0.55, and 0.84 ± 0.14 weight% for the coacervate and large and small microspheres, respectively, corresponding to mean encapsulation efficiencies of 81.7 ± 12.2 % and 50.9 ± 3.9 % for the large and small microspheres. Sustained drug release was observed in vitro over a clinically relevant 7-day period, with small and large microspheres exhibiting similar elution profiles. Antibiotic release generally followed microsphere degradation as measured by Ca and P ion release. Conclusions: This study demonstrated successful drug loading of calcium polyphosphate microspheres with minocycline. Furthermore, in vitro sustained release of minocycline over a 7-day period was observed, suggesting potential utility of this approach for treating periodontitis.","PeriodicalId":51074,"journal":{"name":"Journal of Applied Biomaterials & Biomechanics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/2280800019863637","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43653523","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}
Pub Date : 2019-04-01DOI: 10.1177/2280800019842150
Taozhou Zhang, Yilong Dai, Yangjun Yan, Yu Zhang, Kun Yu, Hui Liu, Hong-jie Fang, Xier Luo, Li Li
Magnesium alloys have been investigated as biodegradable metallic materials because of their good biocompatibility with natural bone, while zinc has basic safety properties for biomedical applications and is one of the nutritionally essential elements for the human body. The microstructures and properties of some novel designs of bio-Mg-Zn alloys are studied to provide implantations which have an improvement in mechanical properties and corrosion resistance.
{"title":"Comparison of the microstructure and properties of a series of Mg-Zn metallic devices on biomedical applications","authors":"Taozhou Zhang, Yilong Dai, Yangjun Yan, Yu Zhang, Kun Yu, Hui Liu, Hong-jie Fang, Xier Luo, Li Li","doi":"10.1177/2280800019842150","DOIUrl":"https://doi.org/10.1177/2280800019842150","url":null,"abstract":"Magnesium alloys have been investigated as biodegradable metallic materials because of their good biocompatibility with natural bone, while zinc has basic safety properties for biomedical applications and is one of the nutritionally essential elements for the human body. The microstructures and properties of some novel designs of bio-Mg-Zn alloys are studied to provide implantations which have an improvement in mechanical properties and corrosion resistance.","PeriodicalId":51074,"journal":{"name":"Journal of Applied Biomaterials & Biomechanics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49028983","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}
Pub Date : 2019-04-01DOI: 10.1177/2280800019847071
Wei Chen, Yan Liu, Jixiang Zhu, Miao Zhou, Xiaoming Chen
Background: At present, scaffold biomaterials with great biodegradation and biocompatibility are attracting more and more attention. Phosphate bioactive glass (PBG) without Si has been prepared successfully, with a glass transition temperature below 600°C. Calcium carbonate (CC)-based bioceramics with PBG as binder were sintered rapidly at a lower temperature. β-Tricalcium phosphate (β-TCP) has always been used to synthesize clinical ceramics due to its wonderful biocompatibility. Here, we combined the advantages of these raw materials to obtain a novel β-TCP/CC/PBG composite porous ceramic. Method: The preparation process of β-TCP/CC/PBG was optimized by controlling PBG content, NaCl ratio, sintering temperature, and holding time. Ceramic biodegradability was evaluated by soaking in a Tris-HCl buffer in vitro, and biocompatibility of the new material was indicated using CCK-8 tests and a live/dead fluorescence assay. Results: The best mechanical properties of β-TCP/CC/PBG composite porous ceramics were obtained with a PBG content of 60%, at which point the proportion of NaCl exerted the most significant influence on the density, porosity, and mechanical properties of the materials. The weight loss rate of the composite ceramics was 11.30%, which was much higher than that of β-TCP (1.41%) and hydroxyapatite (0.83%) ceramics. CCK-8 test and live/dead fluorescence assay indicated that the composite porous ceramics showed a biocompatibility similar to that of β-TCP ceramics. Conclusion: β-TCP/CC/PBG composite porous ceramics have potential applications in bone regeneration. It is hoped that the novel biomaterial developed in this study will prove useful for the repair of bone defects.
{"title":"Preparation and bioactivity of biodegradable β-tricalcium phosphate / calcium carbonate / phosphate bioactive glass composite porous ceramic","authors":"Wei Chen, Yan Liu, Jixiang Zhu, Miao Zhou, Xiaoming Chen","doi":"10.1177/2280800019847071","DOIUrl":"https://doi.org/10.1177/2280800019847071","url":null,"abstract":"Background: At present, scaffold biomaterials with great biodegradation and biocompatibility are attracting more and more attention. Phosphate bioactive glass (PBG) without Si has been prepared successfully, with a glass transition temperature below 600°C. Calcium carbonate (CC)-based bioceramics with PBG as binder were sintered rapidly at a lower temperature. β-Tricalcium phosphate (β-TCP) has always been used to synthesize clinical ceramics due to its wonderful biocompatibility. Here, we combined the advantages of these raw materials to obtain a novel β-TCP/CC/PBG composite porous ceramic. Method: The preparation process of β-TCP/CC/PBG was optimized by controlling PBG content, NaCl ratio, sintering temperature, and holding time. Ceramic biodegradability was evaluated by soaking in a Tris-HCl buffer in vitro, and biocompatibility of the new material was indicated using CCK-8 tests and a live/dead fluorescence assay. Results: The best mechanical properties of β-TCP/CC/PBG composite porous ceramics were obtained with a PBG content of 60%, at which point the proportion of NaCl exerted the most significant influence on the density, porosity, and mechanical properties of the materials. The weight loss rate of the composite ceramics was 11.30%, which was much higher than that of β-TCP (1.41%) and hydroxyapatite (0.83%) ceramics. CCK-8 test and live/dead fluorescence assay indicated that the composite porous ceramics showed a biocompatibility similar to that of β-TCP ceramics. Conclusion: β-TCP/CC/PBG composite porous ceramics have potential applications in bone regeneration. It is hoped that the novel biomaterial developed in this study will prove useful for the repair of bone defects.","PeriodicalId":51074,"journal":{"name":"Journal of Applied Biomaterials & Biomechanics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45581405","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 Daily disposable contact lenses are gaining in popularity among practitioners and wearers for the improved ocular health and subjective outcomes they offer. Recently a novel daily disposable contact lens material with water gradient technology was introduced. Delefilcon A lenses consist of a 33% water content silicone hydrogel core and an outer hydrogel layer which is totally free of silicone and contains 80% water. Methods The aim of the present study was to confirm the layered structure of delefilcon A contact lenses. Thickness of hydrogel coating on the silicone hydrogel core was assessed using Raman spectroscopy. To investigate the layered structure of the material, depth spectra of the lenses were recorded. Results The results obtained suggest that at about 6 μm a boundary between the hydrogel layer and silicone hydrogel core exists, which is in good agreement with the manufacturer's data. Conclusions Data collected in this experiment confirm a water gradient at the delefilcon A lens surface.
{"title":"Raman Imaging of Layered Soft Contact Lenses","authors":"K. Krysztofiak, Kamila Ciężar, M. Kościński","doi":"10.5301/jabfm.5000329","DOIUrl":"https://doi.org/10.5301/jabfm.5000329","url":null,"abstract":"Background Daily disposable contact lenses are gaining in popularity among practitioners and wearers for the improved ocular health and subjective outcomes they offer. Recently a novel daily disposable contact lens material with water gradient technology was introduced. Delefilcon A lenses consist of a 33% water content silicone hydrogel core and an outer hydrogel layer which is totally free of silicone and contains 80% water. Methods The aim of the present study was to confirm the layered structure of delefilcon A contact lenses. Thickness of hydrogel coating on the silicone hydrogel core was assessed using Raman spectroscopy. To investigate the layered structure of the material, depth spectra of the lenses were recorded. Results The results obtained suggest that at about 6 μm a boundary between the hydrogel layer and silicone hydrogel core exists, which is in good agreement with the manufacturer's data. Conclusions Data collected in this experiment confirm a water gradient at the delefilcon A lens surface.","PeriodicalId":51074,"journal":{"name":"Journal of Applied Biomaterials & Biomechanics","volume":"15 1","pages":"149 - 152"},"PeriodicalIF":0.0,"publicationDate":"2017-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5301/jabfm.5000329","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42012480","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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