多孔型丝素蛋白/羟基磷灰石复合脂肪间充质干细胞修复兔股骨骨缺损

背景：从蚕丝中提取的丝素蛋白具有良好的细胞相容性,且可生物降解,用于修饰生物材料能提高细胞在材料表面的黏附和生长能力。 目的：探讨丝素蛋白/羟基磷灰石材料复合脂肪间充质干细胞修复包含性骨缺损的作用。 方法：取2月龄新西兰大白兔附睾处脂肪组织,经胰酶消化传代培养脂肪间充质干细胞,取第3代兔脂肪间充质干细胞以1×1010 L-1浓度接种于丝素蛋白/羟基磷灰支架材料上,培养3 h后加入含有1 μmol/L地塞米松、50 μmol/L维生素 C、 10 mmol/L β-甘油磷酸钠的DMEM培养液进行成骨诱导。新西兰大白兔36只,在兔股骨远端制备直径4.5 mm、深10 mm的松质骨缺损。细胞复合材料组植入复合脂肪间充质干细胞的丝素蛋白/羟基磷灰石;单纯材料组植入丝素蛋白/羟基磷灰石;空白对照组不作任何植入。 结果与结论：12周时大体观察细胞复合材料组骨缺损区完全被骨组织修复,单纯材料组骨缺损区缩小、部分修复,空白对照组骨缺损无修复。12周时X射线、组织学检查显示细胞复合材料组完全修复了骨缺损区,材料组部分修复了骨缺损区,细胞复合材料组的新生骨小梁多于单纯材料组(P < 0.05),空白对照组未见骨修复。结果说明复合脂肪间充质干细胞的丝素蛋白/羟基磷灰石修复兔股骨包含性骨缺损能力优于单纯丝素蛋白/羟基磷灰石材料。 关键词：丝素蛋白/羟基磷灰石;脂肪间充质干细胞;骨缺损;骨及软骨组织工程支架材料;复合生物材料 doi:10.3969/j.issn.1673-8225.2010.08.003     

多孔丝素蛋白/羟基磷灰石复合脂肪间充质干细胞修复兔关节软骨及软骨下骨缺损

背景：丝素蛋白/羟基磷灰石是细胞立体培养的良好支架,是临床常用的骨缺损修复材料,具有良好的生物相容性。脂肪干细胞具有向骨及软骨细胞分化的潜能,适合骨软骨缺损修复。 目的：观察转化生长因子β1和胰岛素样生长因子1联合成软骨诱导脂肪干细胞与丝素蛋白/羟基磷灰石复合后修复兔关节软骨及软骨下骨缺损的效果。 方法：取新西兰大白兔56只,2只用于传代培养脂肪间充质干细胞,以3×109 L-1浓度接种到丝素蛋白/羟基磷灰石。其余54只新西兰大白兔,在股骨髁间制备软骨缺损模型,随机分为细胞复合材料组、单纯材料组和空白对照组,细胞复合材料组植入复合脂肪间充质干细胞的丝素蛋白/羟基磷灰石;单纯材料组植入丝素蛋白/羟基磷灰石;空白对照组不作任何植入。从大体、影像学、组织学观察比较缺损的修复情况。 结果与结论：12周时大体观察、CT、磁共振和组织学检查细胞材料复合组软骨及软骨下骨缺损区完全被软骨组织修复,修复组织与周围软骨色泽相近,支架材料基本吸收,未见明显退变和白细胞浸润,所有标本均未见丝素蛋白残留。单纯材料组缺损区缩小、部分修复,且呈纤维软骨样修复。空白对照组缺损无明显修复。提示复合脂肪间充质干细胞的丝素蛋白/羟基磷灰石修复兔关节软骨及软骨下骨缺损能力优于单纯丝素蛋白/羟基磷灰石材料。丝素蛋白/羟基磷灰石复合脂肪间充质干细胞可形成透明软骨修复动物膝关节全层软骨缺损,重建关节的解剖结构和功能,可作为新型骨软骨组织工程支架。     

纳米羟基磷灰石-聚羟基丁酸戊酯/聚乙二醇人工骨对骨缺损修复的作用*

背景：为改善羟基磷灰石强度低、韧性差的缺点，尝试将具有良好机械性能的聚羟基丁酸戊酯和高亲水性材料聚乙二醇与之共混制备复合材料。 目的：评价纳米羟基磷灰石-聚羟基丁酸戊酯/聚乙二醇（Nano-HA-PHBV/PEG）人工骨对骨缺损的修复作用，并与单纯纳米羟基磷灰石人工骨相比较。 设计、时间及地点：对比分析，体内动物实验，于2007-06/2008-05在南方医科大学珠江医院中心实验室及生物力学实验室完成。 材料：自制纳米羟基磷灰石人工骨和Nano-HA-PHBV/PEG人工骨。 方法：将30只新西兰兔双侧桡骨中段制成15 mm节段性骨缺损，左侧植入Nano-HA-PHBV/PEG人工骨为实验组，右侧植入纳米羟基磷灰石人工骨为对照组。 主要观察指标：X射线片观察骨缺损修复及材料降解情况；术后2，4，8，16，24周分别处死6只兔子取材，用骨密度测量仪测量缺损修复区骨密度；术后4，8，16，24周在骨密度测试结束后切取完整桡骨标本，行三点抗弯试验测量弯曲强度。 结果：X射线显示4周后两组骨缺损处植入材料均有不同程度的降解，骨缺损处均有新骨形成；实验组新骨密度在材料植入8周后开始高于对照组(P < 0.05)；16，24周时实验组桡骨弯曲强度高于对照组(P < 0.05)。 结论：Nano-HA-PHBV/PEG人工骨具有良好的成骨能力和生物相容性，其成骨能力优于单纯纳米羟基磷灰石人工骨。     

纳米羟基磷灰石/胶原/聚乳酸复合物与骨髓间充质干细胞修复兔下颌骨缺损

背景：为颌骨缺损患者选择适宜的骨移植材料替代自体骨是当前研究的热点。 目的：观察纳米羟基磷灰石/胶原/聚乳酸与兔骨髓间充质干细胞复合物用于修复兔下颌骨缺损的能力，比较其与自体骨修复及单纯纳米羟基磷灰石/胶原/聚乳酸修复的差异。 设计、时间及地点：随机对照动物实验，于2007-03/10在锦州市中心医院动物实验室完成。 材料：40只新西兰兔随机分成纳米羟基磷灰石/胶原/聚乳酸复合骨髓基质干细胞填充组（简称复合组）、自体骨填充组、单纯支架材料填充组及空白对照组，每组10只。 方法：在兔下颌骨体部制造大小为15 mm ×15 mm的全厚骨缺损模型。复合组于缺损处植入骨髓基质干细胞与纳米羟基磷灰石/胶原/聚乳酸体外联合培养14 d的复合物；自体骨填充组于缺损处植入自体髂骨；单纯支架材料充填组于缺损处植入纳米羟基磷灰石/胶原/聚乳酸；空白对照组不作任何植入。 主要观察指标：分别于植入后1，3，6个月进行骨密度检测及组织学染色观察，根据检测结果评价骨修复效果。 结果：复合组与自体骨填充组骨密度比较，差异无显著性 (P > 0.05)，且均高于单纯支架材料充填组及空白对照组(P < 0.01)。复合组和自体骨填充组材料植入后6个月时见，新生骨组织渐成熟，呈大块状，桥接缺损断端，支架材料已所剩无几。单纯支架材料充填组植入后6个月时见，植入区骨小梁增多，但仍见较多纤维组织嵌于其中，易见未降解完全的支架材料。 结论：纳米羟基磷灰石/胶原/聚乳酸与骨髓间充质干细胞复合物修复下颌骨缺损效果与自体骨修复相似，均优于单纯支架材料修复。     

纳米级羟基磷灰石/骨形态发生蛋白复合物修复兔桡骨大段缺损及局部血管内皮细胞生长因子的表达

摘要 背景：研究发现,在小段骨缺损中植入骨或仿生骨组织,坏死组织逐渐被替换,移植骨中会长入有活性的血管肉芽组织,移植骨被吸收,新骨主动形成。但在大段骨缺损,这一过程发生较慢且不完全。 目的：观察纳米级羟基磷灰石材料复合骨形态发生蛋白后大段骨缺损修复能力及诱导生成血管能力。 方法：制作兔桡骨大段骨缺损模型,抽签随机分2组,选择一侧分别植入纳米级羟基磷灰石/骨形态发生蛋白、纳米级羟基磷灰石修复,均以另一侧为空白对照。植入后6个月行大体观察、X射线、组织形态学检查、组织切片碱性磷酸酶染色、成骨量分析、血管内皮细胞生长因子阳性细胞率及阳性血管数检测。 结果与结论：空白对照组基本无骨组织生成。纳米级羟基磷灰石植入后被新生骨组织分割成小块,材料原有结构破坏。纳米级羟基磷灰石/骨形态发生蛋白组较纳米级羟基磷灰石组残存材料更少,材料降解更为彻底。纳米级羟基磷灰石/骨形态发生蛋白组成骨量、血管内皮细胞生长因子表达及血管内皮细胞生长因子阳性血管数目均明显高于纳米级羟基磷灰石组(P < 0.001),且血管内皮细胞生长因子表达与血管内皮细胞生长因子阳性血管数目成正比关系。说明纳米级羟基磷灰石与骨形态发生蛋白复合后,骨修复能力进一步增强,诱导血管生成能力明显提高。 关键词：纳米级羟基磷灰石;血管内皮细胞生长因子;骨形态发生蛋白;血管生成;纳米生物材料 doi:10.3969/j.issn.1673-8225.2011.12.006     

磷酸氢钙/胶原复合人工骨与羟基磷灰石/胶原复合人工骨修复大段骨缺损的比较

摘要 背景：羟基磷灰石及与其他成分的复合体已成为国际通用的骨修复材料,广泛用于临床治疗及实验研究,其生物相容性已得到充分验证,但其可降解性能差及诱导骨缺损再生能力有限也为大家公认。作者认为用羟基磷灰石作为骨诱导材料只是机械地模仿天然骨的成分,用其他钙磷盐作为无机成分有可能突破现有科研思维的定势,为人工骨的研发代来新的突破。 目的：比较磷酸氢钙/胶原复合人工骨和羟基磷灰石/胶原复合人工骨的骨传导性和骨诱导性。 方法：使用15只新西兰大白兔作为实验动物,制备左侧尺骨1 cm全缺损,分别植入磷酸氢钙/胶原复合人工骨、标准羟基磷灰石/胶原复合人工骨和合成羟基磷灰石/胶原复合人工骨。术后92 d拍X射线片后处死动物进行解剖观察及组织学观察。 结果与结论：磷酸氢钙/胶原复合人工骨组动物术后92 d的X射线照片显示缺损处由于骨组织增生完全愈合,处死动物进行解剖可见缺损处修复与未手术部位外观接近。组织切片可见缺损处形成骨板并完全骨化,骨单位明显,尚未形成明显的层状骨板,散布的骨窝中有骨细胞,中央管可见新生血管,未见人工骨残留,人工骨被彻底降解吸收。标准羟基磷灰石/胶原复合人工骨组植入92 d愈合处成骨较差,易折断。合成羟基磷灰石/胶原复合人工骨组植入92 d不愈合。实验表明南京脉迪森医药科技有限公司生产的磷酸氢钙/胶原复合人工骨(仿松质骨生物活性人工骨)的骨传导性和骨诱导性能明显优于羟基磷灰石/胶原复合人工骨。 关键词：磷酸氢钙;羟基磷灰石;人工骨;胶原蛋白;体内实验 doi:10.3969/j.issn.1673-8225.2010.47.005     

肝素-壳聚糖复合体-羟基磷灰石-米诺环素新型仿生纳米复合材料修复兔胫骨缺损

摘要 背景：仿生纳米复合材料具有与自体骨相似的组成和结构,有广泛的应用前景。 目的：观察肝素-壳聚糖-羟基磷灰石-米诺环素仿生纳米复合材料修复兔胫骨缺损的效果。 方法：取20只健康成年新西兰大白兔,制作胫骨上端15 mm×8 mm的腔隙性临界性骨缺损。随机数字表分为实验组(n =16)和空白对照组(n =4)。实验组植入课题组研制的肝素-壳聚糖复合体-磷灰石-米诺环素仿生纳米复合骨修复材料新型复合材料,空白对照组不进行干预。分别于植入后2,4,8,12周行大体观察、X射线平片及组织学观察新型骨修复材料的骨修复效果。 结果与结论：大体观察显示实验组植入后8周后缺损已经融合,12周时塑形接近正常。X射线平片显示随着时间延长,实验组骨缺损骨痂增多,12周基本愈合,塑形完成,空白对照组未见骨性修复,形成骨不连。组织学观察实验组植入后4周材料开始吸收,8周后降解被新生骨取代,12周完全修复,空白对照组各时间点均由纤维组织充填。提示新型肝素-壳聚糖复合体-羟基磷灰石-米诺环素仿生纳米复合材料能有效促进临界性骨缺损的修复。 关键词：肝素;羟基磷灰石;米诺环素;壳聚糖;组织工程 doi:10.3969/j.issn.1673-8225.2011.12.002     

聚氨酯/纳米羟基磷灰石+聚酰胺66一体化复合支架材料修复软骨及软骨下骨缺损

背景：目前软骨支架材料种类繁多,随着制备工艺、结构及表面改性技术的提高,材料的性能更加完善,而一体化修复关节软骨及软骨下骨缺损对于软骨替代材料的稳定性十分重要。 目的：观察新型生物复合材料聚氨酯/纳米羟基磷灰石+聚酰胺66一体化修复关节软骨及软骨下骨缺损的效果。 方法：将多孔聚氨酯/纳米羟基磷灰石+聚酰胺66、致密聚氨酯/纳米羟基磷灰石+聚酰胺66及单纯纳米羟基磷灰石+聚酰胺66材料植入狗膝关节,空白组作为对照,分别于4,12,24周,对动物行大体观察,局部行组织学切片观察,对支架材料植入后24周修复组织进行组织学评分,扫描电镜观察生物材料与周边软骨连接界面的情况。 结果与结论：支架材料植入后12,24周,下层材料中可见有骨组织长入,多孔聚氨酯与周边软骨融合较好,周边软骨未见明显退变。植入后24周,扫描电镜见上层材料多孔聚氨酯与周围正常软骨结合牢固,未见明显间隙,周围软骨未见明显退变;致密聚氨酯与周边正常软骨有较明显间隙,周边正常软骨退行性改变,变薄、卷曲。说明新型多孔聚氨酯/纳米羟基磷灰石+聚酰胺66支架材料在结构上更加接近正常软骨及软骨下骨,对软骨及软骨下骨缺损的修复效果更加显著。 关键词：聚氨酯;纳米羟基磷灰石;聚酰胺66;组织工程;关节软骨;软骨下骨;修复 doi:10.3969/j.issn.1673-8225.2010.16.009     

脱钙骨/聚乳酸重组人工骨的体内生物学特性

背景：前期实验证实脱钙骨/聚乳酸重组人工骨不仅孔隙率、孔径、机械强度等性能符合人工骨材料的要求,并且结合了两种材料的优势,具有明显的促进细胞贴附、增殖作用。 目的：进一步探讨脱钙骨/聚乳酸重组人工骨在体内的生物相容性、降解情况及成骨特点,评价其性能。 方法：将脱钙骨/聚乳酸重组人工骨随机植入成年新西兰白兔1.5 cm的桡骨缺损及一侧臀肌内,并设立不植入任何材料的空白对照组。观察脱钙骨/聚乳酸重组人工骨植入后动物局部反应,检测血钙值;植入后6,8,12,16周取骨缺损处标本作X射线、骨矿含量、大体标本及组织形态学观察,臀肌处标本仅作组织形态学观察,分析不同时期组织反应、骨缺损修复及材料降解情况。 结果与结论：脱钙骨/聚乳酸重组人工骨植入后无明显的局部不良反应,血钙值无明显变化;骨缺损内骨矿含量在植入6~16周内升高幅度明显高于空白对照组;X射线、大体标本及组织形态学观察显示,脱钙骨/聚乳酸重组人工骨的成骨方式主要是骨传导成骨,至植入后16周时骨缺损基本修复,而空白对照骨缺损断端仅有少量骨修复,形成骨不连;脱钙骨/聚乳酸重组人工骨植入后即开始其降解过程,12周以后材料周围出现较多吞噬有材料颗粒的巨噬细胞和多核巨细胞,16周时仍有部分材料未降解吸收。结果证实脱钙骨/聚乳酸重组人工骨具备良好的生物相容性和骨传导成骨能力,可以在体内逐渐发生生物降解。 关键词：脱钙骨;骨替代材料;聚乳酸;降解;生物相容性材料 doi:10.3969/j.issn.1673-8225.2010.25.003     

丝素蛋白/羟基磷灰石材料复合骨髓间充质干细胞构建组织工程化软骨

背景：随着组织工程的兴起,软骨损伤的修复可能性显著地提高,但单一的支架材料均不能符合理想支架,有一定的局限性。 目的：观察骨髓间充质干细胞复合丝素蛋白/羟基磷灰石构建组织工程化软骨的可行性。 方法：体外分离培养骨髓间充质干细胞,并定向诱导成软骨细胞,与丝素蛋白/羟基磷灰石复合培养,构建膝关节胫骨平台全层关节软骨缺损。54只大白兔单侧膝关节全层软骨缺损模型后随机抽签法分为3组,复合组植入细胞-丝素蛋白/羟基磷灰石复合物;材料组植入单纯丝素蛋白/羟基磷灰石,对照组不行任何植入。植入后8,12周CT检查及组织学检查观察软骨缺损修复情况。 结果与结论：植入后8周,复合组关节面不平整,关节间隙增大,形成新生类软骨细胞,基质丰富。材料组关节面塌陷,软骨细胞少量增殖。植入后12周,复合组关节面平整,关节间隙如常。大量软骨细胞出现,与周边软骨色泽一样,支架材料完全降解。材料组关节面不平整,软骨细胞不完全充填,支架材料部分降解。对照组未见修复。提示用骨髓间充质干细胞复合丝素蛋白/羟基磷灰石可形成透明软骨修复动物膝关节全层软骨缺损,显示了丝素蛋白/羟基磷灰石材料作为关节软骨组织工程支架材料的良好生物相容性。     

Tongue/palate contact for the production of /s/ and /z/

Productions of /s/ and /z/ by ten adult speakers were investigated using the electropalatograph (EPG). The participants, ten speech researchers who spoke English as their first language, recorded productions of /s/ and /z/ in nonsense and real words. The maximum contact frame was used as the point of reference to compare tongue/palate contact for each production. Each speaker had alveolar contact, lateral bracing and most had a midline groove for both /s/ and /z/; however, the array of contacted electrodes was unique for each speaker. The groove widths and lengths ranged from 0–3 electrodes. There was significantly greater alveolar tongue/palate contact for /z/ compared to /s/ in word‐initial position, but not in word‐final position for the following measures: alveolar palatal contact, medial groove width, medial groove length. However, when measures of total palate contact and centre of gravity were considered, there was a complex interaction between the phonemes /s/ and /z/, coarticulation with the vowel, word position, and word context (real and nonsense words).     

Tongue/palate contact for the production of /s/ and /z/

Productions of /s/ and /z/ by ten adult speakers were investigated using the electropalatograph (EPG). The participants, ten speech researchers who spoke English as their first language, recorded productions of /s/ and /z/ in nonsense and real words. The maximum contact frame was used as the point of reference to compare tongue/palate contact for each production. Each speaker had alveolar contact, lateral bracing and most had a midline groove for both /s/ and /z/; however, the array of contacted electrodes was unique for each speaker. The groove widths and lengths ranged from 0-3 electrodes. There was significantly greater alveolar tongue/palate contact for /z/ compared to /s/ in word-initial position, but not in word-final position for the following measures: alveolar palatal contact, medial groove width, medial groove length. However, when measures of total palate contact and centre of gravity were considered, there was a complex interaction between the phonemes /s/ and /z/, coarticulation with the vowel, word position, and word context (real and nonsense words).     

Electropalatographic specification of Croatian fricatives /s/ and /z/

Electropalatographic specification of alveolar fricatives in Croatian is aimed at providing speech therapists with normative data about the range of acceptable productions of /s/ and /z/ in adult speakers of Croatian. Four variables were analysed: place of articulation, total contact, groove width and hold phase duration. Intra- and inter-speaker variability for each variable was analysed. Lingual palatal cues for voicing difference were also quantified and discussed. Results show that Croatian /s/ and /z/ are alveolar and not dental as previously reported. The comparison between the voiced and the voiceless fricative shows that durational measures provide the best differentiation. The voiceless counterpart is significantly longer. The difference between voiced and voiceless is also found in the total contact, with /z/ having more contact in the anterior four rows of electrodes, while /s/ has more contact in the posterior four rows of electrodes. This difference is also reflected in the anterior and the posterior groove widths. Possibilities of using these results as normative data for the diagnosis and treatment of atypical articulation of /s/ and /z/ are discussed.     

A comparative study of contractile responses in diaphragm muscles of normal and dystrophic (C57BL6Jdy2Jdy2J) mice

Potassium and caffeine contractures of isolated small bundles (100 to 200 μm diameter) of muscle fibers isolated from the diaphragm of normal and dystrophic ($\text{C57BL}\text{6J}\text{dy}{}^{\mathrm{2J}}\text{dy}{}^{\mathrm{2J}}$) mice were compared. In diaphragms of pathologic mice (3 to 5 months old) the resting potential, the characteristics of the twitch, and some histological examinations were typical of dystrophic muscles. The slopes of the relationships between the steady membrane potential and log [K]₀ were similar for the two types of cells. In 110 mM and 146 mM K there were no significant differences in the time course of the contractures and reduction in [Ca]₀ decreased the time to peak and the time constant of relaxation to the same extent; the relative efficiency of [Mg]₀ compared with [Ca]₀ was equivalent. Repriming of K contractures at different external calcium concentrations indicated that the normal diaphragm did not have any special advantage. The exposure of isolated strips to a solution containing caffeine resulted in a similar increase of the strength of the regularly evoked twitch responses. However, the contractures elicited by 1.25 to 20 mM caffeine showed a subsensitivity of the dystrophic diaphragm (K_mDys = 9.3 K_mN) and the rate of relaxation was significantly slower than in normal muscle (in 20 mM caffeine, 50% decay time for normal muscle was 25.2 ± 7.6 s and for dystrophic muscle 54.8 ± 11.2 s. THese results suggest an absence of major alterations in the mechanism of excitation-contraction coupling associated with dystrophy, except for a change in the specific element of the sarcoplasmic reticulum where caffeine acts.     

Rate and extent of functional reinnervation in fast-twitch and slow-twitch muscles of the dystrophic mouse (C57Bl6Jdy2jdy2j)

The extent of functional reinnervation of fast-twitch extensor digitorum longus muscle in dystrophic and normal mice was determined at various times after nerve transection. Functional reinnervation was assessed by measuring the twitch tension evoked by stimulation of the nerve central to the site of transection. In control mice aged 4 to 6 weeks at the time of denervation, complete reinnervation was observed after 6 weeks. In dystrophic mice of the same age reinnervation was clearly impaired. The ratio of functional innervation of the operated leg to that of the contralateral unoperated leg was only 0.62 after 6 weeks. In older dystrophic mice (4 to 6 months at the time of nerve transection) the reinnervation ratio was even lower, 0.43 after 12 weeks. Reinnervation of slow-twitch soleus muscle was assessed 8 weeks after denervation and was also found to be reduced in the older dystrophic animals. The extent of reinnervation was reflected in the measured values of muscle weight, twitch tension per unit wet weight, and twitch time course. The impairment of reinnervation of dystrophic muscle is consistent with, but not proof of, a neurogenic defect in murine muscular dystrophy.