β-Tricalcium Phosphate(β-TCP),one of the most used bone graft substitutes,may contain up to 5 wt%foreign phase according to standards.Typical foreign phases includeβ-calcium pyrophosphate(β-CPP)and hydroxyapatite(...β-Tricalcium Phosphate(β-TCP),one of the most used bone graft substitutes,may contain up to 5 wt%foreign phase according to standards.Typical foreign phases includeβ-calcium pyrophosphate(β-CPP)and hydroxyapatite(HA).Currently,the effect of small amounts of impurities on β-TCP resorption is unknown.This is surprising since pyrophosphate is a very potent osteoclast inhibitor.The main aim of this study was to assess the effect of small β-CPP fractions(<1 wt%)on the in vitro osteoclastic resorption of β-TCP.A minor aim was to examine the effect of β-CPP and HA impurities on the physico-chemical properties of β-TCP powders and sintered cylinders.Twenty-six batches of β-TCP powder were produced with a Ca/P molar ratio varying between 1.440 and 1.550.Fifteen were further processed to obtain dense and polished β-TCP cylinders.Finally,six of them,with a Ca/P molar ratio varying between 1.496(1 wt% β-CPP)and 1.502(1 wt% HA),were incubated in the presence of osteoclasts.Resorption was quantified by white-light interferometry.Osteoclastic resorption was significantly inhibited by β-CPP fraction in a linear manner.The presence of 1% β-CPP reduced β-TCP resorption by 40%,which underlines the importance of controllingβ-CPP content when assessing β-TCP biological performance.展开更多
β-咔啉结构广泛存在于生物活性分子之中,为探索非酸性反应条件下合成β-咔啉衍生物的方法,以色胺类化合物和醛类为原料,以改进的Pictet-Spengler反应为关键步骤,再经氧化脱氢合成4个多取代β-咔啉化合物(2a~2d),其结构经1 H NMR和MS(E...β-咔啉结构广泛存在于生物活性分子之中,为探索非酸性反应条件下合成β-咔啉衍生物的方法,以色胺类化合物和醛类为原料,以改进的Pictet-Spengler反应为关键步骤,再经氧化脱氢合成4个多取代β-咔啉化合物(2a~2d),其结构经1 H NMR和MS(ESI)确证。经过对Pictet-Spengler反应步骤中物料比、溶剂、反应温度与时间进行考察后发现:在色胺类化合物为2.0 mmol,醛为3.0 mmol,六氟异丙醇钙为0.4 mmol,二氯甲烷为20.0 mL,室温反应24 h的最优条件下,四氢-β-咔啉化合物中间体(1a~1d)的收率为75%~89%,反应存在取代基效应,含芳香性基团底物收率较高。展开更多
基金the Swiss National Science Foundation for its funding(Grant no.200021_169027).
文摘β-Tricalcium Phosphate(β-TCP),one of the most used bone graft substitutes,may contain up to 5 wt%foreign phase according to standards.Typical foreign phases includeβ-calcium pyrophosphate(β-CPP)and hydroxyapatite(HA).Currently,the effect of small amounts of impurities on β-TCP resorption is unknown.This is surprising since pyrophosphate is a very potent osteoclast inhibitor.The main aim of this study was to assess the effect of small β-CPP fractions(<1 wt%)on the in vitro osteoclastic resorption of β-TCP.A minor aim was to examine the effect of β-CPP and HA impurities on the physico-chemical properties of β-TCP powders and sintered cylinders.Twenty-six batches of β-TCP powder were produced with a Ca/P molar ratio varying between 1.440 and 1.550.Fifteen were further processed to obtain dense and polished β-TCP cylinders.Finally,six of them,with a Ca/P molar ratio varying between 1.496(1 wt% β-CPP)and 1.502(1 wt% HA),were incubated in the presence of osteoclasts.Resorption was quantified by white-light interferometry.Osteoclastic resorption was significantly inhibited by β-CPP fraction in a linear manner.The presence of 1% β-CPP reduced β-TCP resorption by 40%,which underlines the importance of controllingβ-CPP content when assessing β-TCP biological performance.
