Pub Date : 2000-06-15DOI: 10.1002/(sici)1097-4636(20000615)50:4<598::aid-jbm16>3.0.co;2-#
R L Messer, J E Doeller, D W Kraus, L C Lucas
Most cellular functions evaluated for biocompatibility are high-energy processes such as proliferation and therefore are not usually affected before a decrease in energy production is observed. Several studies have shown that metabolic functions are altered at much lower concentrations than several normally used biocompatibility tests such as viability. Therefore, the purpose of this study was to provide an in-depth evaluation of metallic ion effects on mitochondria function and thereby biocompatibility. These studies evaluated the mitochondrial function of human gingival fibroblasts exposed to the salt solutions of ions released from nickel-based dental alloys, particularly beryllium (Be(2+)), chromium (Cr(6+) and Cr(3+)), nickel (Ni(2+)), and molybdenum (Mo(6+)). Mitochondrial function was examined by NADH:CoQ reductase activity, succinate dehydrogenase activity, and oxygen consumption.
{"title":"An investigation of fibroblast mitochondria enzyme activity and respiration in response to metallic ions released from dental alloys.","authors":"R L Messer, J E Doeller, D W Kraus, L C Lucas","doi":"10.1002/(sici)1097-4636(20000615)50:4<598::aid-jbm16>3.0.co;2-#","DOIUrl":"https://doi.org/10.1002/(sici)1097-4636(20000615)50:4<598::aid-jbm16>3.0.co;2-#","url":null,"abstract":"<p><p>Most cellular functions evaluated for biocompatibility are high-energy processes such as proliferation and therefore are not usually affected before a decrease in energy production is observed. Several studies have shown that metabolic functions are altered at much lower concentrations than several normally used biocompatibility tests such as viability. Therefore, the purpose of this study was to provide an in-depth evaluation of metallic ion effects on mitochondria function and thereby biocompatibility. These studies evaluated the mitochondrial function of human gingival fibroblasts exposed to the salt solutions of ions released from nickel-based dental alloys, particularly beryllium (Be(2+)), chromium (Cr(6+) and Cr(3+)), nickel (Ni(2+)), and molybdenum (Mo(6+)). Mitochondrial function was examined by NADH:CoQ reductase activity, succinate dehydrogenase activity, and oxygen consumption.</p>","PeriodicalId":15159,"journal":{"name":"Journal of biomedical materials research","volume":"50 4","pages":"598-604"},"PeriodicalIF":0.0,"publicationDate":"2000-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21606888","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 : 2000-05-01DOI: 10.1002/(sici)1097-4636(200005)50:2<125::aid-jbm5>3.0.co;2-#
P Frayssinet, D Mathon, A Lerch, A Autefage, P Collard, N Rouquet
The resistance of macroporous calcium phosphate ceramics to compressive strength generally is low and depends on, among other factors, porosity percentage and pore size. A compromise always is adopted between high porosity, required for a good integration, and mechanical strength, which increases with material density. We improved the strength of macroporous calcium phosphate ceramics of interconnected porosity by filling the pores with a highly soluble, self-setting calcium phosphate cement made of TCP and DCPD. Cylinders of the resulting material were implanted in sheep condyles and subjected to histological analysis after 20, 60, and 120 days. Microradiographs were made of the histological sections. The control material consisted of ceramic that had not been loaded with cement. Progressive ingrowth of bone into the ceramic pores occurred as the cement was degraded during the first implantation period. Marked degradation of the cement was apparent after 2 months, with fragmentation of the cement in most of the pores and the presence of bone tissue between the fragments. All the cement had been replaced by bone after 4 months. Some fragments of cement still were embedded in the newly formed bone. There was no significant difference between the integration of loaded and nonloaded ceramics. Filling the macroporous ceramic pores with a calcium phosphate cement significantly improved the mechanical strength of these ceramics without modifying their integration in the healing bone.
{"title":"Osseointegration of composite calcium phosphate bioceramics.","authors":"P Frayssinet, D Mathon, A Lerch, A Autefage, P Collard, N Rouquet","doi":"10.1002/(sici)1097-4636(200005)50:2<125::aid-jbm5>3.0.co;2-#","DOIUrl":"https://doi.org/10.1002/(sici)1097-4636(200005)50:2<125::aid-jbm5>3.0.co;2-#","url":null,"abstract":"<p><p>The resistance of macroporous calcium phosphate ceramics to compressive strength generally is low and depends on, among other factors, porosity percentage and pore size. A compromise always is adopted between high porosity, required for a good integration, and mechanical strength, which increases with material density. We improved the strength of macroporous calcium phosphate ceramics of interconnected porosity by filling the pores with a highly soluble, self-setting calcium phosphate cement made of TCP and DCPD. Cylinders of the resulting material were implanted in sheep condyles and subjected to histological analysis after 20, 60, and 120 days. Microradiographs were made of the histological sections. The control material consisted of ceramic that had not been loaded with cement. Progressive ingrowth of bone into the ceramic pores occurred as the cement was degraded during the first implantation period. Marked degradation of the cement was apparent after 2 months, with fragmentation of the cement in most of the pores and the presence of bone tissue between the fragments. All the cement had been replaced by bone after 4 months. Some fragments of cement still were embedded in the newly formed bone. There was no significant difference between the integration of loaded and nonloaded ceramics. Filling the macroporous ceramic pores with a calcium phosphate cement significantly improved the mechanical strength of these ceramics without modifying their integration in the healing bone.</p>","PeriodicalId":15159,"journal":{"name":"Journal of biomedical materials research","volume":"50 2","pages":"125-30"},"PeriodicalIF":0.0,"publicationDate":"2000-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/(sici)1097-4636(200005)50:2<125::aid-jbm5>3.0.co;2-#","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21533143","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 : 2000-03-15DOI: 10.1002/(sici)1097-4636(20000315)49:4<534::aid-jbm12>3.0.co;2-#
V F Sechriest, Y J Miao, C Niyibizi, A Westerhausen-Larson, H W Matthew, C H Evans, F H Fu, J K Suh
The quality of articular cartilage engineered using a cell-polymer construct depends, in part, on the chemical composition of the biomaterial and whether that biomaterial can support the chondrocytic phenotype. Acknowledging the supportive influence of tissue-specific matrix molecules on the chondrocytic phenotype, we have combined chondroitin sulfate-A (CSA) and chitosan, a glycosaminoglycan (GAG) analog, to develop a novel biomaterial to support chondrogenesis. Chitosan is a polycationic repeating monosaccharide of beta-1,4-linked glucosamine monomers with randomly located N-acetyl glucosamine units. Chitosan may be combined with the polyanionic CSA such that ionic crosslinking results in hydrogel formation. Bovine primary articular chondrocytes, when seeded onto a thin layer of CSA-chitosan, form discrete, focal adhesions to the material and maintain many characteristics of the differentiated chondrocytic phenotype, including round morphology, limited mitosis, collagen type II, and proteoglycan production. Our findings suggest CSA-chitosan may be well suited as a carrier material for the transplant of autologous chondrocytes or as a scaffold for the tissue engineering of cartilage-like tissue.
使用细胞聚合物构建的关节软骨工程的质量部分取决于生物材料的化学成分以及该生物材料是否能够支持软骨细胞表型。认识到组织特异性基质分子对软骨细胞表型的支持作用,我们将硫酸软骨素- a (CSA)和壳聚糖(一种糖胺聚糖(GAG)类似物)结合起来,开发了一种支持软骨形成的新型生物材料。壳聚糖是一种多阳离子重复单糖,由-1,4-氨基葡萄糖单体和随机定位的n -乙酰氨基葡萄糖单体组成。壳聚糖可与聚阴离子CSA结合,使离子交联形成水凝胶。牛原代关节软骨细胞,当播种到薄层csa -壳聚糖上时,形成离散的、局灶性的粘附,并保持分化软骨细胞表型的许多特征,包括圆形形态、有限的有丝分裂、II型胶原和蛋白多糖的产生。本研究结果提示csa -壳聚糖可作为自体软骨细胞移植的载体材料或软骨样组织工程的支架。
{"title":"GAG-augmented polysaccharide hydrogel: a novel biocompatible and biodegradable material to support chondrogenesis.","authors":"V F Sechriest, Y J Miao, C Niyibizi, A Westerhausen-Larson, H W Matthew, C H Evans, F H Fu, J K Suh","doi":"10.1002/(sici)1097-4636(20000315)49:4<534::aid-jbm12>3.0.co;2-#","DOIUrl":"https://doi.org/10.1002/(sici)1097-4636(20000315)49:4<534::aid-jbm12>3.0.co;2-#","url":null,"abstract":"<p><p>The quality of articular cartilage engineered using a cell-polymer construct depends, in part, on the chemical composition of the biomaterial and whether that biomaterial can support the chondrocytic phenotype. Acknowledging the supportive influence of tissue-specific matrix molecules on the chondrocytic phenotype, we have combined chondroitin sulfate-A (CSA) and chitosan, a glycosaminoglycan (GAG) analog, to develop a novel biomaterial to support chondrogenesis. Chitosan is a polycationic repeating monosaccharide of beta-1,4-linked glucosamine monomers with randomly located N-acetyl glucosamine units. Chitosan may be combined with the polyanionic CSA such that ionic crosslinking results in hydrogel formation. Bovine primary articular chondrocytes, when seeded onto a thin layer of CSA-chitosan, form discrete, focal adhesions to the material and maintain many characteristics of the differentiated chondrocytic phenotype, including round morphology, limited mitosis, collagen type II, and proteoglycan production. Our findings suggest CSA-chitosan may be well suited as a carrier material for the transplant of autologous chondrocytes or as a scaffold for the tissue engineering of cartilage-like tissue.</p>","PeriodicalId":15159,"journal":{"name":"Journal of biomedical materials research","volume":"49 4","pages":"534-41"},"PeriodicalIF":0.0,"publicationDate":"2000-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21459724","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 : 2000-01-01DOI: 10.1002/1097-4636(2000)53:6<799::aid-jbm22>3.0.co;2-#
J C Lin, C W Lin, X Z Lin
Cyanoacrylates have known for their ability to polymerize rapidly in the presence of traces of weakly basic moieties such as water. The tissue adhesive, Histoacryl(R) (N-butyl 2-cyanoacrylate), has been reported to control bleeding through endoscopic sclerotherapy. But the commercially available Histoacryl(R) is expensive, and it has the problem like other cyanoacrylates that the glue tends to flow/run away from the point of application, which is inherent to the low viscosity, making precise application difficult. In this study, ethyl cyanoacrylate (ECA), the main constituent of "super glue," was employed instead of Histoacryl(R) due to its lower cost. The aim of the research is to modify the compositions of ECA regimen and evaluate its feasibility for sclerosant application through both in vitro flow circuit model and in vivo animal tests. It was noted that the difference in the relative hardening rate between the in vitro Hepes-Tyrodes buffer flowing model and the in vivo rat model for the ECA and Histoacryl(R) was related to the existence of the blood protein, such as albumin, in the physiological milieu. It was also noticed that the ECA setting rate was greatly increased either in Hepes-Tyrodes buffer or in blood (to a comparable rate as Histoacryl(R) in vivo) by adding a few doses of caffeine, which acts as a polymerization initiator. This would lead to far better injection precision during sclerotherapy. Furthermore, in vivo histological examination for the occluded lumen of the rat's inferior vena cava and a clinical piglet portal vein occlusion experiment have suggested this new sclerosant regimen, caffeine/ECA, is of great promise in endoscopic sclerotherapy.
{"title":"In vitro and in vivo studies for modified ethyl cyanoacrylate regimens for sclerotherapy.","authors":"J C Lin, C W Lin, X Z Lin","doi":"10.1002/1097-4636(2000)53:6<799::aid-jbm22>3.0.co;2-#","DOIUrl":"https://doi.org/10.1002/1097-4636(2000)53:6<799::aid-jbm22>3.0.co;2-#","url":null,"abstract":"<p><p>Cyanoacrylates have known for their ability to polymerize rapidly in the presence of traces of weakly basic moieties such as water. The tissue adhesive, Histoacryl(R) (N-butyl 2-cyanoacrylate), has been reported to control bleeding through endoscopic sclerotherapy. But the commercially available Histoacryl(R) is expensive, and it has the problem like other cyanoacrylates that the glue tends to flow/run away from the point of application, which is inherent to the low viscosity, making precise application difficult. In this study, ethyl cyanoacrylate (ECA), the main constituent of \"super glue,\" was employed instead of Histoacryl(R) due to its lower cost. The aim of the research is to modify the compositions of ECA regimen and evaluate its feasibility for sclerosant application through both in vitro flow circuit model and in vivo animal tests. It was noted that the difference in the relative hardening rate between the in vitro Hepes-Tyrodes buffer flowing model and the in vivo rat model for the ECA and Histoacryl(R) was related to the existence of the blood protein, such as albumin, in the physiological milieu. It was also noticed that the ECA setting rate was greatly increased either in Hepes-Tyrodes buffer or in blood (to a comparable rate as Histoacryl(R) in vivo) by adding a few doses of caffeine, which acts as a polymerization initiator. This would lead to far better injection precision during sclerotherapy. Furthermore, in vivo histological examination for the occluded lumen of the rat's inferior vena cava and a clinical piglet portal vein occlusion experiment have suggested this new sclerosant regimen, caffeine/ECA, is of great promise in endoscopic sclerotherapy.</p>","PeriodicalId":15159,"journal":{"name":"Journal of biomedical materials research","volume":"53 6","pages":"799-805"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/1097-4636(2000)53:6<799::aid-jbm22>3.0.co;2-#","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21901201","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 : 2000-01-01DOI: 10.1002/(sici)1097-4636(2000)53:1<67::aid-jbm9>3.0.co;2-#
J Benevenia, M Zimmerman, J Keating, F Cyran, M Blacksin, J R Parsons
In a bilateral canine tibial model, the mechanical, radiologic, and histologic characteristics of intercalary allografts stabilized with locked intramedullary nails were compared with those of allografts fixed with compression plates. Both methods of fixation achieved healing to host bone. Tibiae that were plated had more callus with statistically greater mean torsional rigidity and strength than those treated with nails (paired t-test, p = 0.05). On average, tibiae which had been plated had much higher bending rigidity than those fixed with locked nails; however, the difference in means was not statistically significant. Histomorphometric analysis showed an overall greater total bone formation in those limbs treated with plates compared to nails (paired t-test, p = 0.04). The mechanical environment created by the different fixation methods are thought to be responsible for the observed differences in healing pattern. The traditional concept of fixation for allografts to achieve maximum rigidity of the construct may not necessarily promote the most appropriate host healing response in all situations. A less rigid fixation method (plates) produced more callus resulting in superior torsional and bending properties. These data show that in this canine intercalary allograft model, limbs fixed with plates produced more external callus resulting in stronger, more rigid healing.
{"title":"Mechanical environment affects allograft incorporation.","authors":"J Benevenia, M Zimmerman, J Keating, F Cyran, M Blacksin, J R Parsons","doi":"10.1002/(sici)1097-4636(2000)53:1<67::aid-jbm9>3.0.co;2-#","DOIUrl":"https://doi.org/10.1002/(sici)1097-4636(2000)53:1<67::aid-jbm9>3.0.co;2-#","url":null,"abstract":"<p><p>In a bilateral canine tibial model, the mechanical, radiologic, and histologic characteristics of intercalary allografts stabilized with locked intramedullary nails were compared with those of allografts fixed with compression plates. Both methods of fixation achieved healing to host bone. Tibiae that were plated had more callus with statistically greater mean torsional rigidity and strength than those treated with nails (paired t-test, p </= 0.05). On average, tibiae which had been plated had much higher bending rigidity than those fixed with locked nails; however, the difference in means was not statistically significant. Histomorphometric analysis showed an overall greater total bone formation in those limbs treated with plates compared to nails (paired t-test, p </= 0.04). The mechanical environment created by the different fixation methods are thought to be responsible for the observed differences in healing pattern. The traditional concept of fixation for allografts to achieve maximum rigidity of the construct may not necessarily promote the most appropriate host healing response in all situations. A less rigid fixation method (plates) produced more callus resulting in superior torsional and bending properties. These data show that in this canine intercalary allograft model, limbs fixed with plates produced more external callus resulting in stronger, more rigid healing.</p>","PeriodicalId":15159,"journal":{"name":"Journal of biomedical materials research","volume":"53 1","pages":"67-72"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/(sici)1097-4636(2000)53:1<67::aid-jbm9>3.0.co;2-#","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21490720","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 : 1999-12-05DOI: 10.1002/(sici)1097-4636(19991205)47:3<379::aid-jbm13>3.0.co;2-#
D B Haddow, R M France, R D Short, S MacNeil, R A Dawson, G J Leggett, E Cooper
Human keratinocytes were cultured on plasma copolymers (PCPs), self-assembled monolayers (SAMs), and tissue culture poly(styrene) (TCPS). Plasma copolymerization was used to deposit films with controlled concentrations of carboxylic acid functional groups (<5%). Human keratinocytes were cultured onto these PCP surfaces, TCPS, and collagen I. A hydrocarbon plasma polymer surface was used as the negative control. Keratinocyte attachment was measured at 24 h and cell proliferation and growth at 3 and 7 days using optical microscopy and DNA concentrations. The PCP surfaces were compared with two SAM systems comprising pure acid and pure hydrocarbon functionalities, and pure gold was used as a control surface. PCP surfaces containing carboxylic acid functionalities promoted keratinocyte attachment. The level of attachment on these surfaces was comparable to that seen on collagen I, a preferred substratum for the culturing of keratinocytes. After several days in culture the cells were well attached and proliferative, forming confluent sheets of keratinocytes. This result was confirmed by DNA assays that suggested the acid PCP surfaces were performing as well as collagen I. Keratinocytes attached well to gold and acid-terminated SAMs but attached poorly to methyl-terminated SAMs. The acid functionality also promoted proliferation and growth of keratinocytes after several days in culture. DNA assays revealed that keratinocyte growth on the acid surface was higher than on collagen I.
{"title":"Comparison of proliferation and growth of human keratinocytes on plasma copolymers of acrylic acid/1,7-octadiene and self-assembled monolayers.","authors":"D B Haddow, R M France, R D Short, S MacNeil, R A Dawson, G J Leggett, E Cooper","doi":"10.1002/(sici)1097-4636(19991205)47:3<379::aid-jbm13>3.0.co;2-#","DOIUrl":"https://doi.org/10.1002/(sici)1097-4636(19991205)47:3<379::aid-jbm13>3.0.co;2-#","url":null,"abstract":"<p><p>Human keratinocytes were cultured on plasma copolymers (PCPs), self-assembled monolayers (SAMs), and tissue culture poly(styrene) (TCPS). Plasma copolymerization was used to deposit films with controlled concentrations of carboxylic acid functional groups (<5%). Human keratinocytes were cultured onto these PCP surfaces, TCPS, and collagen I. A hydrocarbon plasma polymer surface was used as the negative control. Keratinocyte attachment was measured at 24 h and cell proliferation and growth at 3 and 7 days using optical microscopy and DNA concentrations. The PCP surfaces were compared with two SAM systems comprising pure acid and pure hydrocarbon functionalities, and pure gold was used as a control surface. PCP surfaces containing carboxylic acid functionalities promoted keratinocyte attachment. The level of attachment on these surfaces was comparable to that seen on collagen I, a preferred substratum for the culturing of keratinocytes. After several days in culture the cells were well attached and proliferative, forming confluent sheets of keratinocytes. This result was confirmed by DNA assays that suggested the acid PCP surfaces were performing as well as collagen I. Keratinocytes attached well to gold and acid-terminated SAMs but attached poorly to methyl-terminated SAMs. The acid functionality also promoted proliferation and growth of keratinocytes after several days in culture. DNA assays revealed that keratinocyte growth on the acid surface was higher than on collagen I.</p>","PeriodicalId":15159,"journal":{"name":"Journal of biomedical materials research","volume":"47 3","pages":"379-87"},"PeriodicalIF":0.0,"publicationDate":"1999-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21352050","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 : 1999-03-15DOI: 10.1002/(sici)1097-4636(19990315)44:4<422::aid-jbm8>3.0.co;2-#
I R Gibson, S M Best, W Bonfield
Bioceramic specimens have been prepared by incorporating a small amount of silicon (0.4 wt %) into the structure of hydroxyapatite [Ca10(PO4)6(OH)2, HA] via an aqueous precipitation reaction to produce a silicon-substituted hydroxyapatite (Si-HA). The results of chemical analysis confirmed the proposed substitution of the silicon (or silicate) ion for the phosphorus (or phosphate) ion in hydroxyapatite. The Si-HA was produced by first preparing a silicon-substituted apatite (Si-Ap) by a precipitation process. A single-phase Si-HA was obtained by heating/calcining the as-prepared Si-Ap to temperatures above 700 degrees C; no secondary phases, such as tricalcium phosphate (TCP), tetracalcium phosphate (TeCP), or calcium oxide (CaO), were observed by X-ray diffraction analysis. Although the X-ray diffraction patterns of Si-HA and stoichiometric HA appeared to be identical, refinement of the diffraction data revealed some small structural differences between the two materials. The silicon substitution in the HA lattice resulted in a small decrease in the a axis and an increase in the c axis of the unit cell. This substitution also caused a decrease in the number of hydroxyl (OH) groups in the unit cell, which was expected from the proposed substitution mechanism. The incorporation of silicon in the HA lattice resulted in an increase in the distortion of the PO4 tetrahedra, indicated by an increase in the distortion index. Analysis of the Si-HA by Fourier transform infrared (FTIR) spectroscopy indicated that although the amount of silicon incorporated into the HA lattice was small, silicon substitution appeared to affect the FTIR spectra of HA, in particular the P-O vibrational bands. The results demonstrate that phase-pure silicon-substituted hydroxyapatite may be prepared using a simple precipitation technique.
{"title":"Chemical characterization of silicon-substituted hydroxyapatite.","authors":"I R Gibson, S M Best, W Bonfield","doi":"10.1002/(sici)1097-4636(19990315)44:4<422::aid-jbm8>3.0.co;2-#","DOIUrl":"https://doi.org/10.1002/(sici)1097-4636(19990315)44:4<422::aid-jbm8>3.0.co;2-#","url":null,"abstract":"<p><p>Bioceramic specimens have been prepared by incorporating a small amount of silicon (0.4 wt %) into the structure of hydroxyapatite [Ca10(PO4)6(OH)2, HA] via an aqueous precipitation reaction to produce a silicon-substituted hydroxyapatite (Si-HA). The results of chemical analysis confirmed the proposed substitution of the silicon (or silicate) ion for the phosphorus (or phosphate) ion in hydroxyapatite. The Si-HA was produced by first preparing a silicon-substituted apatite (Si-Ap) by a precipitation process. A single-phase Si-HA was obtained by heating/calcining the as-prepared Si-Ap to temperatures above 700 degrees C; no secondary phases, such as tricalcium phosphate (TCP), tetracalcium phosphate (TeCP), or calcium oxide (CaO), were observed by X-ray diffraction analysis. Although the X-ray diffraction patterns of Si-HA and stoichiometric HA appeared to be identical, refinement of the diffraction data revealed some small structural differences between the two materials. The silicon substitution in the HA lattice resulted in a small decrease in the a axis and an increase in the c axis of the unit cell. This substitution also caused a decrease in the number of hydroxyl (OH) groups in the unit cell, which was expected from the proposed substitution mechanism. The incorporation of silicon in the HA lattice resulted in an increase in the distortion of the PO4 tetrahedra, indicated by an increase in the distortion index. Analysis of the Si-HA by Fourier transform infrared (FTIR) spectroscopy indicated that although the amount of silicon incorporated into the HA lattice was small, silicon substitution appeared to affect the FTIR spectra of HA, in particular the P-O vibrational bands. The results demonstrate that phase-pure silicon-substituted hydroxyapatite may be prepared using a simple precipitation technique.</p>","PeriodicalId":15159,"journal":{"name":"Journal of biomedical materials research","volume":"44 4","pages":"422-8"},"PeriodicalIF":0.0,"publicationDate":"1999-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21264319","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 : 1999-01-01DOI: 10.1002/(sici)1097-4636(1999)48:2<165::aid-jbm11>3.0.co;2-#
C Trépanier, T K Leung, M Tabrizian, L H Yahia, J G Bienvenu, J F Tanguay, D L Piron, L Bilodeau
Nickel-titanium (NiTi) offers many advantages for the fabrication of coronary stents: shape memory, superelasticity, and radiopacity. However, many authors highlighted the selective dissolution of Ni from the alloy during the corrosion process that could lead to potential toxicity. The improvement of the NiTi stent's corrosion resistance by different surface treatments (electropolishing, heat treatment, and nitric acid passivation) was reported in a previous article. In the present study a comparative biocompatibility evaluation of such stents was performed through in vitro and in vivo assays. A cell proliferation test was completed to evaluate the cytotoxicity of surface treated NiTi using human fibroblasts. Then a stent implantation was performed in rabbit paramuscular muscle to study the inflammatory response generated by the same implants. Cell proliferation tests generally indicated an in vitro biocompatibility of our samples similar to the control group. An in vivo implantation study demonstrated the gradual overall reduction with time of the fibrocellular capsule thickness surrounding the implants. After a 12-week implantation period, the fibrous capsules surrounding the different implants tended toward the same value of 0.07 mm, which suggested that all surface treatments produced a similar biological response. This low value of the fibrocellular capsule indicated that our NiTi surface treated implants were relatively inert.
{"title":"Preliminary investigation of the effects of surface treatments on biological response to shape memory NiTi stents.","authors":"C Trépanier, T K Leung, M Tabrizian, L H Yahia, J G Bienvenu, J F Tanguay, D L Piron, L Bilodeau","doi":"10.1002/(sici)1097-4636(1999)48:2<165::aid-jbm11>3.0.co;2-#","DOIUrl":"https://doi.org/10.1002/(sici)1097-4636(1999)48:2<165::aid-jbm11>3.0.co;2-#","url":null,"abstract":"<p><p>Nickel-titanium (NiTi) offers many advantages for the fabrication of coronary stents: shape memory, superelasticity, and radiopacity. However, many authors highlighted the selective dissolution of Ni from the alloy during the corrosion process that could lead to potential toxicity. The improvement of the NiTi stent's corrosion resistance by different surface treatments (electropolishing, heat treatment, and nitric acid passivation) was reported in a previous article. In the present study a comparative biocompatibility evaluation of such stents was performed through in vitro and in vivo assays. A cell proliferation test was completed to evaluate the cytotoxicity of surface treated NiTi using human fibroblasts. Then a stent implantation was performed in rabbit paramuscular muscle to study the inflammatory response generated by the same implants. Cell proliferation tests generally indicated an in vitro biocompatibility of our samples similar to the control group. An in vivo implantation study demonstrated the gradual overall reduction with time of the fibrocellular capsule thickness surrounding the implants. After a 12-week implantation period, the fibrous capsules surrounding the different implants tended toward the same value of 0.07 mm, which suggested that all surface treatments produced a similar biological response. This low value of the fibrocellular capsule indicated that our NiTi surface treated implants were relatively inert.</p>","PeriodicalId":15159,"journal":{"name":"Journal of biomedical materials research","volume":"48 2","pages":"165-71"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/(sici)1097-4636(1999)48:2<165::aid-jbm11>3.0.co;2-#","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21201699","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 : 1999-01-01DOI: 10.1002/(sici)1097-4636(1999)48:3<354::aid-jbm21>3.0.co;2-#
J S Marotta, C W Widenhouse, M B Habal, E P Goldberg
Although it is well known that silicone gel breast implants (SGBIs) produce many "local" complications (i.e., pain, hard fibrous capsules, disfigurement, chronic inflammation, implant shell failure) and necessitate frequent surgical revisions, no large cohort retrospective quantitative analysis of clinical data has been reported to date, especially for the prevalence of failures and additional surgeries. Data from 35 different studies that encompass more than 8000 explanted SGBIs have now been analyzed and are reported here. Because examination of a prosthesis when explanted is the definitive method for determining shell integrity, the only studies that were used were ones that reported implant duration, the total number of SGBIs explanted, and the number of SGBIs for which shell rupture or failure ("not intact") was confirmed upon surgical removal. An exponential regression plot of data indicated a direct correlation of implant duration with percent shell failure (r2 = 0. 63 and r = 0.79 ). SGBI failure was found to be 30% at 5 years, 50% at 10 years, and 70% at 17 years. The failure rate was 6% per year during the first 5 years following primary implant surgery. ANOVA comparison of three implant age groups (mean implant durations of 3. 9, 10.2, and 18.9 years) indicated a highly significant statistical correlation of percent failure with implant duration (p < 0.001). Complications necessitating at least one additional surgery occurred for 33% of implants within 6 years following primary implant surgery. Shell failure was found to be an order of magnitude greater than the 4 to 6% rupture prevalence suggested by the AMA Council on Scientific Affairs in 1993, the 0.2 to 1.1% cited by manufacturers at that time, and the 5% rupture that was stated to be "not a safety standard that the FDA can accept."
虽然硅胶乳房植入物(sgbi)会产生许多“局部”并发症(如疼痛、硬纤维囊、毁容、慢性炎症、植入物外壳失效)并需要频繁的手术修复,但迄今为止还没有对临床数据进行大规模队列回顾性定量分析的报道,特别是关于失败率和额外手术的报道。来自35项不同研究的数据,涵盖了8000多个外植的sgbi,现已被分析并在此报告。由于对移植假体进行检查是确定假体外壳完整性的最终方法,因此我们所采用的研究仅报道了种植体持续时间、移植的sgbi总数,以及手术切除后确认外壳破裂或失效(“不完整”)的sgbi数量。数据的指数回归图显示种植体持续时间与外壳损坏百分比直接相关(r2 = 0)。63, r = 0.79)。5年SGBI失败率为30%,10年为50%,17年为70%。初次种植手术后的前5年,失败率为每年6%。三个种植年龄组的方差分析比较(平均种植时间为3。9、10.2和18.9年)显示失败率与种植体持续时间高度显著相关(p < 0.001)。在初次种植体手术后的6年内,33%的种植体出现并发症,需要至少进行一次额外的手术。1993年,美国医学协会科学事务委员会提出的破裂率为4%至6%,当时制造商提出的破裂率为0.2%至1.1%,而5%的破裂率被认为“不是FDA可以接受的安全标准”,而壳牌的破裂率被发现比这高出一个数量级。
{"title":"Silicone gel breast implant failure and frequency of additional surgeries: analysis of 35 studies reporting examination of more than 8,000 explants.","authors":"J S Marotta, C W Widenhouse, M B Habal, E P Goldberg","doi":"10.1002/(sici)1097-4636(1999)48:3<354::aid-jbm21>3.0.co;2-#","DOIUrl":"https://doi.org/10.1002/(sici)1097-4636(1999)48:3<354::aid-jbm21>3.0.co;2-#","url":null,"abstract":"<p><p>Although it is well known that silicone gel breast implants (SGBIs) produce many \"local\" complications (i.e., pain, hard fibrous capsules, disfigurement, chronic inflammation, implant shell failure) and necessitate frequent surgical revisions, no large cohort retrospective quantitative analysis of clinical data has been reported to date, especially for the prevalence of failures and additional surgeries. Data from 35 different studies that encompass more than 8000 explanted SGBIs have now been analyzed and are reported here. Because examination of a prosthesis when explanted is the definitive method for determining shell integrity, the only studies that were used were ones that reported implant duration, the total number of SGBIs explanted, and the number of SGBIs for which shell rupture or failure (\"not intact\") was confirmed upon surgical removal. An exponential regression plot of data indicated a direct correlation of implant duration with percent shell failure (r2 = 0. 63 and r = 0.79 ). SGBI failure was found to be 30% at 5 years, 50% at 10 years, and 70% at 17 years. The failure rate was 6% per year during the first 5 years following primary implant surgery. ANOVA comparison of three implant age groups (mean implant durations of 3. 9, 10.2, and 18.9 years) indicated a highly significant statistical correlation of percent failure with implant duration (p < 0.001). Complications necessitating at least one additional surgery occurred for 33% of implants within 6 years following primary implant surgery. Shell failure was found to be an order of magnitude greater than the 4 to 6% rupture prevalence suggested by the AMA Council on Scientific Affairs in 1993, the 0.2 to 1.1% cited by manufacturers at that time, and the 5% rupture that was stated to be \"not a safety standard that the FDA can accept.\"</p>","PeriodicalId":15159,"journal":{"name":"Journal of biomedical materials research","volume":"48 3","pages":"354-64"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/(sici)1097-4636(1999)48:3<354::aid-jbm21>3.0.co;2-#","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21265327","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}