The Experts below are selected from a list of 22779 Experts worldwide ranked by ideXlab platform
ângela Maria Moraes - One of the best experts on this subject based on the ideXlab platform.
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phosphorylation of chitosan to improve osteoinduction of chitosan xanthan based scaffolds for periosteal tissue engineering
International Journal of Biological Macromolecules, 2020Co-Authors: Renata Francielle Bombaldi De Souza, Fernanda Carla Bombaldi De Souza, Andrea Thorpe, Diego Mantovani, Ketul C Popat, ângela Maria MoraesAbstract:Abstract The periosteum is a membrane that surrounds bones, providing essential cellular and biological components for fracture healing and bone repair. Tissue engineered scaffolds able to function as periosteum substitutes can significantly improve bone regeneration in severely injured tissues. Efforts to develop more bioactive and tunable periosteal substitutes are required to improve the success of this tissue engineering approach. In this work, a chemical modification was performed in chitosan, a polysaccharide with osteoconductive properties, by introducing phosphate groups to its structure. The phosphorylated polymer (Chp) was used to produce chitosan-xanthan-based scaffolds for periosteal tissue engineering. Porous and mechanically reinforced matrices were obtained with addition of the surfactant Kolliphor® P188 and the silicone rubber Silpuran® 2130A/B. Scaffolds properties, such as large pore sizes (850–1097 μm), Micro-Roughness and thickness (0.7–3.5 mm in culture medium), as well as low thrombogenicity compared to standard implantable materials, extended degradation time and negligible cytotoxicity, enable their application as periosteum substitutes. Moreover, the higher adsorption of bone morphogenetic protein mimic (cytochrome C) by Chp-based formulations suggests improved osteoinductivity of these materials, indicating that, when used in vivo, the material would be able to concentrate native BMPs and induce osteogenesis. The scaffolds produced were not toxic to adipose tissue-derived stem cells, however, cell adhesion and proliferation on the scaffolds surfaces can be still further improved. The mineralization observed on the surface of all formulations indicates that the materials studied have promising characteristics for the application in bone regeneration.
Jan Eirik Ellingsen - One of the best experts on this subject based on the ideXlab platform.
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effect of Micro Roughness produced by tio2 blasting tensile testing of bone attachment by using coin shaped implants
Biomaterials, 2002Co-Authors: Hans Jacob Ronold, Jan Eirik EllingsenAbstract:The aim of the present study was to examine bone response to Micro-rough titanium implants. Forty coin-shaped implants were divided into eight groups according to their surface Roughness. The first group had electropolished surfaces. The surfaces of implant groups 2–8 were blasted with TiO2 particles with incremental grain sizes ranging from 7.5–12.5 to 270–330mm. Five implants from each group were placed into the cortical bone of the proximal tibia in New Zealand Black rabbits. To avoid bone overgrowth during the retention phase the implants were fitted into tight polytetrafluoroethylene (PTFE) caps leaving only the flat test surface exposed to bone. The healing period was set to 10 weeks, and implants with attached bone were evaluated using a tensile testing machine. In groups 1–7 a significant correlation between the Micro-Roughness of the implant surfaces and retention strength was observed. Maximum bone bonding was observed with implants blasted with 180–220mm grain size (group 7). Blasting with larger TiO2 particles appeared to decrease the effect. The findings suggest that the best grain size of TiO2 particles for optimising retention of titanium implants in cortical bone should be in the 180–220mm range. r 2002 Elsevier Science Ltd. All rights reserved.
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effect of Micro Roughness produced by tio2 blasting tensile testing of bone attachment by using coin shaped implants
Biomaterials, 2002Co-Authors: Hans Jacob Ronold, Jan Eirik EllingsenAbstract:The aim of the present study was to examine bone response to Micro-rough titanium implants. Forty coin-shaped implants were divided into eight groups according to their surface Roughness. The first group had electropolished surfaces. The surfaces of implant groups 2-8 were blasted with TiO2 particles with incremental grain sizes ranging from 7.5-12.5 to 270-330 Microns. Five implants from each group were placed into the cortical bone of the proximal tibia in New Zealand Black rabbits. To avoid bone overgrowth during the retention phase the implants were fitted into tight polytetrafluoroethylene (PTFE) caps leaving only the flat test surface exposed to bone. The healing period was set to 10 weeks, and implants with attached bone were evaluated using a tensile testing machine. In groups 1-7 a significant correlation between the Micro-Roughness of the implant surfaces and retention strength was observed. Maximum bone bonding was observed with implants blasted with 180-220 Microns grain size (group 7). Blasting with larger TiO2 particles appeared to decrease the effect. The findings suggest that the best grain size of TiO2 particles for optimising retention of titanium implants in cortical bone should be in the 180-220 Microns range.
Renata Francielle Bombaldi De Souza - One of the best experts on this subject based on the ideXlab platform.
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phosphorylation of chitosan to improve osteoinduction of chitosan xanthan based scaffolds for periosteal tissue engineering
International Journal of Biological Macromolecules, 2020Co-Authors: Renata Francielle Bombaldi De Souza, Fernanda Carla Bombaldi De Souza, Andrea Thorpe, Diego Mantovani, Ketul C Popat, ângela Maria MoraesAbstract:Abstract The periosteum is a membrane that surrounds bones, providing essential cellular and biological components for fracture healing and bone repair. Tissue engineered scaffolds able to function as periosteum substitutes can significantly improve bone regeneration in severely injured tissues. Efforts to develop more bioactive and tunable periosteal substitutes are required to improve the success of this tissue engineering approach. In this work, a chemical modification was performed in chitosan, a polysaccharide with osteoconductive properties, by introducing phosphate groups to its structure. The phosphorylated polymer (Chp) was used to produce chitosan-xanthan-based scaffolds for periosteal tissue engineering. Porous and mechanically reinforced matrices were obtained with addition of the surfactant Kolliphor® P188 and the silicone rubber Silpuran® 2130A/B. Scaffolds properties, such as large pore sizes (850–1097 μm), Micro-Roughness and thickness (0.7–3.5 mm in culture medium), as well as low thrombogenicity compared to standard implantable materials, extended degradation time and negligible cytotoxicity, enable their application as periosteum substitutes. Moreover, the higher adsorption of bone morphogenetic protein mimic (cytochrome C) by Chp-based formulations suggests improved osteoinductivity of these materials, indicating that, when used in vivo, the material would be able to concentrate native BMPs and induce osteogenesis. The scaffolds produced were not toxic to adipose tissue-derived stem cells, however, cell adhesion and proliferation on the scaffolds surfaces can be still further improved. The mineralization observed on the surface of all formulations indicates that the materials studied have promising characteristics for the application in bone regeneration.
Hans Jacob Ronold - One of the best experts on this subject based on the ideXlab platform.
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effect of Micro Roughness produced by tio2 blasting tensile testing of bone attachment by using coin shaped implants
Biomaterials, 2002Co-Authors: Hans Jacob Ronold, Jan Eirik EllingsenAbstract:The aim of the present study was to examine bone response to Micro-rough titanium implants. Forty coin-shaped implants were divided into eight groups according to their surface Roughness. The first group had electropolished surfaces. The surfaces of implant groups 2–8 were blasted with TiO2 particles with incremental grain sizes ranging from 7.5–12.5 to 270–330mm. Five implants from each group were placed into the cortical bone of the proximal tibia in New Zealand Black rabbits. To avoid bone overgrowth during the retention phase the implants were fitted into tight polytetrafluoroethylene (PTFE) caps leaving only the flat test surface exposed to bone. The healing period was set to 10 weeks, and implants with attached bone were evaluated using a tensile testing machine. In groups 1–7 a significant correlation between the Micro-Roughness of the implant surfaces and retention strength was observed. Maximum bone bonding was observed with implants blasted with 180–220mm grain size (group 7). Blasting with larger TiO2 particles appeared to decrease the effect. The findings suggest that the best grain size of TiO2 particles for optimising retention of titanium implants in cortical bone should be in the 180–220mm range. r 2002 Elsevier Science Ltd. All rights reserved.
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effect of Micro Roughness produced by tio2 blasting tensile testing of bone attachment by using coin shaped implants
Biomaterials, 2002Co-Authors: Hans Jacob Ronold, Jan Eirik EllingsenAbstract:The aim of the present study was to examine bone response to Micro-rough titanium implants. Forty coin-shaped implants were divided into eight groups according to their surface Roughness. The first group had electropolished surfaces. The surfaces of implant groups 2-8 were blasted with TiO2 particles with incremental grain sizes ranging from 7.5-12.5 to 270-330 Microns. Five implants from each group were placed into the cortical bone of the proximal tibia in New Zealand Black rabbits. To avoid bone overgrowth during the retention phase the implants were fitted into tight polytetrafluoroethylene (PTFE) caps leaving only the flat test surface exposed to bone. The healing period was set to 10 weeks, and implants with attached bone were evaluated using a tensile testing machine. In groups 1-7 a significant correlation between the Micro-Roughness of the implant surfaces and retention strength was observed. Maximum bone bonding was observed with implants blasted with 180-220 Microns grain size (group 7). Blasting with larger TiO2 particles appeared to decrease the effect. The findings suggest that the best grain size of TiO2 particles for optimising retention of titanium implants in cortical bone should be in the 180-220 Microns range.
Marianna Peroglio - One of the best experts on this subject based on the ideXlab platform.
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Human primary osteoblast behaviour on Microrough zirconia-toughened alumina and on selectively etched Microrough zirconia-toughened alumina
Journal of the European Ceramic Society, 2018Co-Authors: Ana-maria Stanciuc, Meinhard Kuntz, Quentin Flamant, Katia Biotteau-deheuvels, Martin Stoddart, Alessandro Porporati, Laurent Gremillard, Marc Anglada, Mauro Alini, Marianna PeroglioAbstract:Hip arthroplasty cementless acetabular components require excellent mechanical properties, biocompatibility, low friction and good osseointegration with surrounding bone tissue. Zirconia-toughened alumina (ZTA) fulfils these demands but requires combination with a rough metal shell for adequate osseointegration. Surface modifications of ZTA could allow a metal-free solution, thus preserving the bone stock for an eventual revision surgery. In this study, selective chemical etching proved to be an innovative method for the introduction of nano-features on Micro-rough surfaces obtained by injection moulding. Results suggest that Micro-Roughness, fluorine enrichment and nano-porosity at the surface of ZTA play a synergistic role on human osteoblast (hOb) maturation. Among the tested groups, hydrofluoric acid etched “medium” Roughness (Sa = 330 nm) ZTA showed the highest and/or earliest ALP expression at both the protein and gene level, while MicroRoughness alone induced only minor effects on hOb maturation on ZTA.