Porous β-tricalcium phosphate (TCP) displays osteoinductivity in certain animals in the absence of osteoinductive agents. We evaluated whether the microstructure may be an important determinant of osteoinduction, and...Porous β-tricalcium phosphate (TCP) displays osteoinductivity in certain animals in the absence of osteoinductive agents. We evaluated whether the microstructure may be an important determinant of osteoinduction, and also investigated how bone formation was promoted using β-TCP combined with bone marrow aspirates. We prepared two types of β-TCP, namely, β-TCP A, which possessed interconnected macropores and micropores, and β-TCP B, which possessed macropores but had less detectable micropores. These were implanted with or without marrow in canine muscles. Bone formation and the resorption of each β-TCP implant were evaluated histologically. Newly formed bone began to appear at day 42 in the implants of β-TCP A alone, but the implants of β-TCP B alone did not show any bone formation by day 42. Meanwhile, bone formation was already evident on day 14 by loading with bone marrow aspirates with or without micropores. By immunohistochemistry, the number of cathepsin K-positive cells (osteoclasts) increased as time passed in the implants of β-TCP A alone, while the number of the osteoclasts did not change obviously in the implants of β-TCP B alone from day 14 to 56. Reticular fibrils were evident within the β-TCP A, and were barely observed in the β-TCP B in the silver impregnation. The present result would bring about the possible role to enhance the importance of the surface microstructure for the better osteoinductivity. Our findings suggest that the combination of porous β-TCP and bone marrow facilitates bone formation.展开更多
Regenerative bone implants promote new bone formation and ideally degrade simultaneously to osteogenesis.Although clinically established calcium phosphate bone grafts provide excellent osseointegration and osteoconduc...Regenerative bone implants promote new bone formation and ideally degrade simultaneously to osteogenesis.Although clinically established calcium phosphate bone grafts provide excellent osseointegration and osteoconductive efficacy,they are limited in terms of bioresorption.Magnesium phosphate(MP)based ceramics are a promising alternative,because they are biocompatible,mechanically extremely stable,and degrade much faster than calcium phosphates under physiological conditions.Bioresorption of an implant material can include both chemical dissolution as well as cellular resorption.We investigated the bioresorption of 3D powder printed struvite and newberyite based MP ceramics in vitro by a direct human osteoclast culture approach.The osteoclast response and cellular resorption was evaluated by means of fluorescence and TRAP staining,determination of osteoclast activities(CA II and TRAP),SEM imaging as well as by quantification of the ion release during cell culture.Furthermore,the bioactivity of the materials was investigated via SBF immersion,whereas hydroxyapatite precipitates were analyzed by SEM and EDX measurements.This bioactive coating was resorbed by osteoclasts.In contrast,only chemical dissolution contributed to bioresorption of MP,while no cellular resorption of the materials was observed.Based on our results,we expect an increased bone regeneration effect of MP compared to calcium phosphate based bone grafts and complete chemical degradation within a maximum of 1.5-3.1 years.展开更多
The adoption of grammatical modifier for im- plants or other kinds of biomaterials eventually absorbed by the body has been a long-standing confusing issue, and there are diverse terms in the large fields of research,...The adoption of grammatical modifier for im- plants or other kinds of biomaterials eventually absorbed by the body has been a long-standing confusing issue, and there are diverse terms in the large fields of research, which not only causes the difficulties when searching on the Internet, but also blurs the meaning and boundaries for researchers. Prior unification attempts at laws/standards set the basis for such research fields towards researching, labeling, marketing and instructions for use. Considering this, the typical gram- matical modifiers ＂biodegradable＂, ＂resorbable＂ ＂absorbable＂, along with their noun forms used in the decades of scien- tific research have been reviewed and explained, interdiscipli- nary in chemistry, ecology, materials science, biology, micro- biology, medicine, and based on usage customs, laws, stan- dards and markets. The term ＂biodegradable＂ has been not only used in biomaterials but also in ecology waste manage- ment, biomedicine and even natural environment. Mean- while, the term ＂resorbable＂ has long been used in biological reaction （osteoclast driven bone resorption）, but is inappro- priate for implants that do not carry the potential to grow back into their original form. The term ＂absorbable＂ focuses more on the host metabolism to the foreign biodegradation products of the implanted material/device compared with the term ＂degradable/biodegradable＂. Meanwhile the coherence and normalization of the term ＂absorbable＂ carried by its own in laws and standards contributes as well. In general, the au- thors consider the term ＂absorbable＂ to be the best grammat- ical modifier with respect to other adjectives which share the same inherence. A further internationally unified usage is proposed by us.展开更多
文摘Porous β-tricalcium phosphate (TCP) displays osteoinductivity in certain animals in the absence of osteoinductive agents. We evaluated whether the microstructure may be an important determinant of osteoinduction, and also investigated how bone formation was promoted using β-TCP combined with bone marrow aspirates. We prepared two types of β-TCP, namely, β-TCP A, which possessed interconnected macropores and micropores, and β-TCP B, which possessed macropores but had less detectable micropores. These were implanted with or without marrow in canine muscles. Bone formation and the resorption of each β-TCP implant were evaluated histologically. Newly formed bone began to appear at day 42 in the implants of β-TCP A alone, but the implants of β-TCP B alone did not show any bone formation by day 42. Meanwhile, bone formation was already evident on day 14 by loading with bone marrow aspirates with or without micropores. By immunohistochemistry, the number of cathepsin K-positive cells (osteoclasts) increased as time passed in the implants of β-TCP A alone, while the number of the osteoclasts did not change obviously in the implants of β-TCP B alone from day 14 to 56. Reticular fibrils were evident within the β-TCP A, and were barely observed in the β-TCP B in the silver impregnation. The present result would bring about the possible role to enhance the importance of the surface microstructure for the better osteoinductivity. Our findings suggest that the combination of porous β-TCP and bone marrow facilitates bone formation.
基金funded by the Deutsche Forschungsgemeinschaft,grant number 417069397,as a collaboration project between the Ludwig Maximilians University Munich and the University Clinic of Würzburgthe DFG for funding the crossbeam scanning electron microscope Zeiss CB 340(INST 105022/58-1 FUGG)within the DFG State Major Instrumentation Programme。
文摘Regenerative bone implants promote new bone formation and ideally degrade simultaneously to osteogenesis.Although clinically established calcium phosphate bone grafts provide excellent osseointegration and osteoconductive efficacy,they are limited in terms of bioresorption.Magnesium phosphate(MP)based ceramics are a promising alternative,because they are biocompatible,mechanically extremely stable,and degrade much faster than calcium phosphates under physiological conditions.Bioresorption of an implant material can include both chemical dissolution as well as cellular resorption.We investigated the bioresorption of 3D powder printed struvite and newberyite based MP ceramics in vitro by a direct human osteoclast culture approach.The osteoclast response and cellular resorption was evaluated by means of fluorescence and TRAP staining,determination of osteoclast activities(CA II and TRAP),SEM imaging as well as by quantification of the ion release during cell culture.Furthermore,the bioactivity of the materials was investigated via SBF immersion,whereas hydroxyapatite precipitates were analyzed by SEM and EDX measurements.This bioactive coating was resorbed by osteoclasts.In contrast,only chemical dissolution contributed to bioresorption of MP,while no cellular resorption of the materials was observed.Based on our results,we expect an increased bone regeneration effect of MP compared to calcium phosphate based bone grafts and complete chemical degradation within a maximum of 1.5-3.1 years.
基金supported by the National Key Research and Development Program of China (2016YFC1102402)National Natural Science Foundation of China (NSFC, 51431002)the NSFC and the Research Grants Council (RGC) of Hong Kong Joint Research Scheme (51361165101 and 5161101031)
文摘The adoption of grammatical modifier for im- plants or other kinds of biomaterials eventually absorbed by the body has been a long-standing confusing issue, and there are diverse terms in the large fields of research, which not only causes the difficulties when searching on the Internet, but also blurs the meaning and boundaries for researchers. Prior unification attempts at laws/standards set the basis for such research fields towards researching, labeling, marketing and instructions for use. Considering this, the typical gram- matical modifiers ＂biodegradable＂, ＂resorbable＂ ＂absorbable＂, along with their noun forms used in the decades of scien- tific research have been reviewed and explained, interdiscipli- nary in chemistry, ecology, materials science, biology, micro- biology, medicine, and based on usage customs, laws, stan- dards and markets. The term ＂biodegradable＂ has been not only used in biomaterials but also in ecology waste manage- ment, biomedicine and even natural environment. Mean- while, the term ＂resorbable＂ has long been used in biological reaction （osteoclast driven bone resorption）, but is inappro- priate for implants that do not carry the potential to grow back into their original form. The term ＂absorbable＂ focuses more on the host metabolism to the foreign biodegradation products of the implanted material/device compared with the term ＂degradable/biodegradable＂. Meanwhile the coherence and normalization of the term ＂absorbable＂ carried by its own in laws and standards contributes as well. In general, the au- thors consider the term ＂absorbable＂ to be the best grammat- ical modifier with respect to other adjectives which share the same inherence. A further internationally unified usage is proposed by us.
