灌注法制备离体大鼠心脏脱细胞基质

目的 探索制备离体大鼠心脏脱细胞生物支架材料的新方法,为心脏组织工程研究提供三维立体天然支架.方法 取30只成年SD大鼠心脏,运用冻融加化学萃取的组织工程学方法 (胰蛋白酶、十二烷基硫酸钠和曲拉通X-100)处理离体大鼠心脏,同时观察心脏大体形态及颜色变化,并对脱细胞支架进行基因组DNA分析;HE染色,免疫荧光法,扫描和透射电镜进一步检测鉴定脱细胞支架的生物学特征.结果 心脏脱细胞支架外观透明,包膜完整,维持心脏三维立体结构,肉眼可见心脏内脉管系统;脱细胞支架DNA残留量不及对照组的3%;HE染色、扫描和透射电镜结果 显示,心脏脱细胞生物支架去细胞彻底,细胞外基质网状结构保留完整;免疫荧光结果 表明,胶原、弹性蛋白等细胞外支架成分保留较完整,未见明显细胞核成分残留.结论 运用冻融加化学萃取法所制备的离体心脏脱细胞生物支架去细胞彻底,细胞外基质保留较完整,是较为理想的心脏三维立体生物支架材料.     

组织工程血管基质的制备与改性

目的：完全脱除猪胸主动脉细胞，对脱细胞血管基质进行改性，增强基质的力学强度，制备组织工程血管支架材料。方法：取家猪的新鲜去除外膜胸主动脉20根，随机分成4组，分别采用胰蛋白酶、TritonX-100及十二烷基硫酸钠（SDS）作为脱细胞试剂对猪胸主动脉进行脱细胞处理，并对脱细胞后的血管基质进行改性，采用HE染色、弹力纤维染色、力学性能测试，以评价脱细胞效果以及材料的力学性能。结果：采用1％TritonX-100单独作用84h既能完全脱除细胞，同时又可完整保留血管基质的三维结构，对胶原纤维、弹力纤维的损伤小，是一种较理想的脱细胞方法。对脱细胞后的基质进行冷冻干燥及真空热交联处理，能有效提高材料的机械强度，冷冻干燥24h后真空120℃下热交联处理12h所获得的材料的机械强度最好，断裂强度可达到1．70MPa。结论：以脱细胞血管基质经冷冻干燥和真空热交联处理后，可以作为血管组织工程的支架材料。     

脱细胞膀胱黏膜下层支架材料的生物学评价

背景:脱细胞膀胱黏膜下层是一种天然的细胞外基质生物材料,主要由Ⅰ、Ⅲ型纤维胶原蛋白构成,是一种理想的生物支架材料。目的:脱细胞猪膀胱组织作为组织工程支架材料的生物学评价。方法:取适量健康猪膀胱置于PBS和叠氮钠的混合溶液,浸泡过夜,刮去膀胱黏膜层。用低渗、-80℃反复冻融、DNase和RNase混合液消化和NaOH裂解连续方法制备脱细胞膀胱黏膜下层。通过观察其组织学结构特征、DNA残留、细胞毒性、细胞黏附效果及皮下炎症反应等来综合评价脱细胞膀胱黏膜下层的生物相容性。结果与结论:正常猪的膀胱经改进的脱细胞方法处理后,绝大部分细胞组分被去处,细胞外基质结构保持完好。细胞毒性试验结果显示脱细胞膀胱黏膜下层细胞毒性为1级,DNA提取结果中未见有DNA残留,细胞黏附结果显示猪平滑肌细胞能在脱细胞支架上较好的贴附生长,SD大鼠皮下植入试验显示无明显的炎症反应。结果证实所制备的脱细胞膀胱黏膜下层结构保存完好,有良好的组织相容性,可能成为组织工程修复的替代材料。     

灌注法制备肺脱细胞基质

 背景：对组织器官进行脱细胞,细胞外基质在经过去除细胞和可溶性蛋白处理之后,可维持正常的器官外形及组织结构基质成分。 目的：利用灌注法制备肺脱细胞基质。 方法：将40只Wistar大鼠随机均分为2组,常规麻醉处理后打开胸腔,获得完整的肺组织,实验组利用Langendorff灌注模型构建大鼠全肺脱细胞基质支架,对照组不予以特殊处理。动态观察和记录实验组肺脏颜色和形态变化,分别从2组大鼠肺脏不同部位获取小块组织,利用电子显微镜进行组织学观察,观察两组的Weigert弹力纤维联合Von Gieson结缔组织染色和苏木精-伊红染色情况。 结果与结论：经1%脱氧胆酸钠溶液灌注后,实验组大鼠肺脏颜色逐渐发生改变,表现为从内至外呈分段分叶状逐渐变为白色半透明状,并可观察到清晰肺叶结构,最终肺脏呈现出均一的白色半透明状。经Weigert弹力纤维联合Von Gieson结缔组织染色和苏木精-伊红染色发现,对照组新鲜肺组织切片中含有大量细胞,其中包括毛细血管和成纤维细胞及内皮细胞等,细胞呈整齐排列状,具有完整的肺泡结构,弹性纤维结构清晰,胶原纤维也呈整齐排列状,结构较为紧凑;实验组肺组织细胞基本已消失,仍具有完整的肺泡形态结构,但呈较为疏松的状态且裂隙增大,弹性纤维保存良好,胶原纤维呈较疏松排列状。表明利用灌注法课可有效构建大鼠全肺组织基质支架。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

制备细胞外基质材料组织脱细胞方法的研究与热点

文题释义：细胞外基质：是由大分子构成的错综复杂网络,为细胞的生存及活动提供适宜的场所,并通过信号转导系统影响细胞的形状、代谢、功能、迁移、增殖和分化。 组织脱细胞：在组织工程学范畴中,应用物理、化学、生物等方法将同种异体或异种组织中的细胞裂解、洗脱,从而获得无细胞的细胞外基质支架材料的过程。 背景：细胞外基质构成的生物支架材料目前已被广泛应用于临床治疗和体内外基础研究中,该种材料脱细胞技术的质量至关重要,不彻底的脱细胞效果会导致生物支架材料植入体内后,诱发一系列免疫排斥反应,最终导致治疗的失败。 目的：介绍制备细胞外基质材料组织脱细胞方法的研究进展。 方法：以“extracellular matrix,tissue decellularization,decellularized method,tissue engineering”为检索词,应用计算机检索PubMed数据库检索2005年1月至2019年12月的相关文章;以“acellular tissue,enzymatic modification”为检索词,应用计算机检索Google Patent数据库2014年1月至2019年12月的相关专利。纳入与组织细胞外基质材料脱细胞方法密切相关的文献,排除重复性研究。结果与结论：脱细胞基质材料的制备方法纷繁复杂,主要包括物理法、化学法和生物法3大类。根据不同的组织类型而选择恰当的脱细胞方法可以在完全去除细胞的同时,最大限度地保留细胞外基质的结构和成分。如果脱细胞的效果不充分,则会造成严重的免疫炎症反应。脱细胞组织的酶修饰方法可以不同程度改善组织的柔韧性、弹性、耐摩擦性等,并可以进一步去除组织的免疫原性。另外,正确选择恰当的灭菌方法有助于更好地保留细胞外基质材料的超微结构与机械性能。同时,异种来源的脱细胞生物支架作为植入性医疗器械,应严格遵循食品药品监督管理办法的规定,规定中要求对于细胞外基质产品的最终灭菌方法的选择要根据不同细菌接种量的指导方针。ORCID: 0000-0002-1309-1971(敖强) 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

脱细胞脊髓基质支架的制备及生物特性

背景：以脱细胞脊髓基质材料为构架的脊髓生物支架,已被证实可恢复或部分恢复受损的脊髓神经功能。 目的：介绍脱细胞脊髓基质支架的制备方法和部分生物特性,对近年来其在脊髓组织工程中的应用及进展作一概述。 方法：应用计算机检索 CNKI 和 PubMed 数据库中 2005年1月至2014年10月关于脱细胞脊髓基质支架材料在脊髓损伤中应用的文章,在主题和摘要中,中文以“脱细胞脊髓,支架材料,脊髓损伤,组织工程学”为检索词检索,英文以“acellular spinal cord;engineering tissue;spinal cord injury;scaffold”为检索词进行检索。 结果与结论：脱细胞脊髓基质支架具有较低的抗原性、优良的生物相容性及类似脊髓的三维支架结构,但存在力学性能差及结构不稳定等缺点。通过京尼平、戊二醛等交联剂改性后可明显提高支架的生物性能。目前国内外已对脱细胞脊髓基质支架在神经修复再生方面的应用做了一些探索,为脊髓组织工程学打下了基础。由于脱细胞脊髓基质支架的诸多优点,脱细胞脊髓基质材料有望成为脊髓组织工程学的理想材料。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

天然生物材料支架的应用

天然生物材料支架具有与细胞外基质结构相似,生物相容性好等特点,在组织工程中作为细胞培养的支架材料具有明显的优势。羊膜取材容易,易于加工处理,无毒无刺激性,具有抗微生物的特性和促进组织修复的生物学作用;小肠粘膜下层无免疫性,含有多种生长因子,具有促进细胞黏附、增殖和分化等作用。血管、膀胱、软骨等脱细胞基质分别用于相应的组织缺损修补,易达到结构再生和功能的恢复。本文就上述支架材料在组织工程中的应用进行综述。     

牛肌腱冻干脱细胞支架的生物力学特性

背景：目前的脱细胞方法在去除细胞的同时对细胞外基质存在一定的损伤,降低了脱细胞支架的生物力学性能。 目的：分析冻干牛肌腱脱细胞支架的生物力学特性。 方法：取新鲜小牛趾伸屈肌腱,去除小牛肌腱表面的滑膜、腱膜及软组织,双蒸水冲洗干净后低压冻干,通过物理方法制备肌腱纤维束60个,随机均分为两组,实验组于无菌操作下置入丝氨酸蛋白酶抑制剂,室温下持续24 h,无菌PBS冲洗后,再移入低浓度胰酶+乙醇混合溶液中,在不破坏细胞外基质的情况下去除细胞壁,室温下持续5 h,再将纤维束移入脱氧核糖核酸酶溶液中持续5 h,最后将已完成脱细胞步骤的支架使用PBS冲洗48 h,无菌室内室温下干燥;对照组不做处置。检测两组材料的弹性模量、耐久性及最大应力。 结果与结论：两组耐久性相似,但实验组在相同位移处的应力小于对照组;两组弹性模量比较差异无显著性意义,但实验组最大应力低于对照组(P < 0.01)。说明冻干脱细胞支架能够在一定程度上模仿牛肌腱的生物力学功能。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

天然及合成尿道重建支架材料的生物相容性及力学性能

背景：目前应用何种尿道组织工程修复重建支架材料更为合适的争论仍不断出现,其生物相容性及力学特性的评估也鲜见报道。 目的：评估应用于尿道修复重建多种生物材料的力学特性及生物相容性。 方法：脱细胞法制备小肠黏膜下层组织、膀胱脱细胞基质以及脱细胞尿道海绵体基质,同时编织法制备聚乙醇酸支架。单轴拉伸测试测定各类支架生物力学特性,光镜及扫描电镜测定支架表面孔径大小。线粒体代谢活性MTT法检测各种生物材料的细胞毒性。所有支架表面接种海绵体平滑肌细胞,体外培养14 d后进一步评估细胞渗透情况。 结果与结论：生物力学评估显示脱细胞尿道海绵体基质在弹性模量以及断裂强度方面的检测结果明显优于其余材料(P < 0.05)。MTT结果显示所有支架材料均支持正常的细胞生长代谢,并未发现存在明显的细胞毒性。聚乙醇酸在扫描电镜中显示出最大的孔径(> 200 μm),同时脱细胞尿道海绵体基质的尿道面(< 5 μm)和海绵体面(>10 μm)观察到明显不同的孔径大小。细胞接种14 d后聚乙醇酸材料的内部可见种子细胞的广泛分布,在膀胱脱细胞基质以及脱细胞尿道海绵体基质的尿道面未发现有明显的细胞渗透迹象,而小肠黏膜下层组织和脱细胞尿道海绵体基质的海绵体面观察到明显的细胞渗透生长表现。提示所有支架材料显示出良好的生物相容性,同时在力学特性方面也与正常尿道组织相仿,但脱细胞尿道海绵体基质在力学和组织学的诸多参数上具有一定的优越性。     

基因修饰牙龈成纤维细胞及脱细胞真皮基质制备牙周组织工程复合物

背景：前期研究发现人血小板源性生长因子B基因转染的牙龈成纤维细胞能够在体外快速增殖,且能够向胞外分泌血小板源性生长因子BB蛋白。目的：了解人血小板源性生长因子B基因修饰牙龈成纤维细胞植入脱细胞真皮基质后,在体内形成牙周组织工程化复合物的能力。方法：将人血小板源性生长因子B基因转染与未转染的Beagle犬牙龈成纤维细胞分别接种于脱细胞真皮基质上,观察细胞在脱细胞真皮基质上的生长情况。将人血小板源性生长因子B基因转染犬牙龈成纤维细胞-脱细胞真皮基质复合物(实验组)、犬牙龈成纤维细胞-脱细胞真皮基质复合物(对照组)及脱细胞真皮基质(空白组)分别植入裸鼠背部皮下,植入后2,4,8周,取背部标本进行组织学观察。结果与结论：人血小板源性生长因子B基因转染与未转染的犬牙龈成纤维细胞均能在脱细胞真皮基质上良好生长。植入后8周,空白组周围的细胞大面积进入脱细胞真皮基质内,部分脱细胞真皮基质出现完全自体化,尽管细胞进入较多,但新生成的胶原纤维较少,细胞只是占据原有的胶原支架生长;对照组开始出现大面积新生胶原纤维,脱细胞真皮基质上原有的胶原纤维逐步被新生的胶原替代,但原有的胶原结构得到保留;实验组出现大面积完全矿化,可见沿原有胶原支架排列的矿化颗粒。表明接种人血小板源性生长因子B基因修饰牙龈成纤维细胞的脱细胞真皮基质在体内获得了成骨性能。 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

Development and characterisation of a full-thickness acellular porcine bladder matrix for tissue engineering

The aim of this study was to produce a natural, acellular matrix from porcine bladder tissue for use as a scaffold in developing a tissue-engineered bladder replacement. Full-thickness, intact porcine bladders were decellularised by distention and immersion in hypotonic buffer containing 0.1% (w/v) SDS and nuclease enzymes. Histological analysis of the resultant matrices showed they were completely acellular; that the major structural proteins had been retained and that there were some residual poorly soluble intracellular proteins. The amount of DNA per mg dry weight of fresh porcine bladder was 2.8 (+/-0.1) microg/mg compared to 0.1 (+/-0.1) microg/mg in decellularised bladder and biochemical analysis showed proportional differences in the hydroxyproline and glycosaminoglycan content of the tissue before and after decellularisation. Uniaxial tensile testing indicated that decellularisation did not significantly compromise the ultimate tensile strength of the tissue. There was, however, an increase in the collagen and elastin phase slopes indicating decreased extensibility. Cytotoxicity assays using porcine smooth muscle cell cultures excluded the presence of soluble toxins in the biomaterial. In summary, a full-thickness natural acellular matrix retaining the major structural components and strength of the urinary bladder has been successfully developed. The matrix is biocompatible with bladder-derived cells and has potential for use in urological surgery and tissue-engineering applications.     

骨髓间充质干细胞与膀胱脱细胞基质支架的生物相容性

背景：国内外许多研究者一直寻找理想的种子细胞与合适的支架材料复合,试图模拟接近正常生理功能的组织工程化尿路替代物。 目的：探讨骨髓间充质干细胞与兔膀胱脱细胞基质支架的生物相容性。 方法：采用密度梯度离心法分离培养兔骨髓间充质干细胞,将第3代兔骨髓间充质干细胞接种到兔膀胱脱细胞基质上进行复合培养,每天进行细胞计数,连续12 d,绘制细胞生长曲线,以单独培养骨髓间充质干细胞为对照组。 结果与结论：骨髓间充质干细胞成功种植到膀胱脱细胞基质上,倒置显微镜下可见骨髓间充质干细胞从膀胱脱细胞基质边缘爬出,膀胱脱细胞基质周围有大量长梭形骨髓间充质干细胞生长。接种5 d内,两组细胞均呈现出平缓生长的状态,接种6-9 d,生长曲线逐渐变得陡峭,细胞呈倍数状态进行分裂生长,速度较快,接种10-12 d,再次趋于平缓状态。两组细胞生长曲线基本重合,可推断兔骨髓间充质干细胞与膀胱脱细胞基质生物相容性良好。 中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程     

脱细胞脂肪组织制备：能否成为异体注射或原位成脂的软组织填充物

文题释义： 细胞外基质(extracellular matrix,ECM)：是由动物细胞合成并分泌到胞外、分布在细胞表面或细胞之间的大分子,主要是一些多糖和蛋白,或蛋白聚糖。这些物质构成复杂的网架结构,支持并连接组织结构、调节组织的发生和细胞的生理活动。细胞外基质是动物组织的一部分,不属于任何细胞,它决定结缔组织的特性,对于一些动物组织的细胞具有重要作用。 脱细胞脂肪组织：脂肪组织移植已成为整形外科及修复重建领域重要的手段,广泛用于软组织缺损的修复和以美容为目的的软组织填充。来源于脂肪组织由细胞外基质组成的脱细胞基质已成为脂肪医学一个新的发展方向,展示出良好的应用前景。脂肪组织脱细胞基质的产生原因可以分为物理性、化学性、酶学以及多种方法的联合,不同的方法对脂肪组织清除细胞的效果不同,对细胞外基质的影响也不同,最终会使宿主对移植的脱细胞材料产生的反应不同,进而影响脱细胞产品的安全性和有效性。 背景：通过脱细胞脂肪组织构建无种子细胞的组织工程脂肪为当前软组织填充的研究热点。 目的：探讨近年来脱细胞脂肪组织的制备方法对其移植后诱导脂肪再生效果的影响,并展望其临床应用前景。 方法：检索1971年1月至2018年12月 PubMed数据、Elsevier数据库相关文献,英文检索词为“adipose tissue engineering;adipose tissue extracellular matrix;soft tissue repair;angiogenesis;adipogenic induction”。阅读近年国内外与脱细胞脂肪组织制备和移植相关的文献,从脱细胞脂肪组织制备方法的改良,交联细胞因子和生物材料等方面进行总结归纳。 结果与结论：当前研究表明,脂肪组织细胞外基质可作为软组织填充的理想支架材料,植入皮下可募集宿主干细胞并诱导期增殖和成脂分化。但现有的脱细胞方案会导致细胞外基质蛋白和结构的损失,这极大的影响了脱细胞脂肪组织植入体内的脂肪再生能力,但通过超临界二氧化碳设备脱油、机械力预处理、交联细胞因子或生物材料等手段可以减少脱细胞脂肪组织制备过程中细胞外基质蛋白的损失和或补充具有促进组织再生功能的蛋白,最终提高脱细胞脂肪组织移植后的血管和脂肪新生能力。脱细胞脂肪组织由于其天然的成脂诱导能力,在脂肪组织工程中具有强大的应用前景,若能克服其制备流程中细胞外基质蛋白损耗或在安全可控的前提下,有望成为可异体注射并原位成脂的理想软组织填充物。 ORCID: 0000-0002-9784-2874(聂佳莹) 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程     

成熟瘢痕组织与正常皮肤脱细胞真皮基质的生物学性能比较

BACKGROUND: It is necessary to carry out multiple operations to remove the scar in patients with large area of scar, and whether the scar tissue can be recycled has become the focus of the study. OBJECTIVE: To compare the tissue structure, biomechanical properties and biocompatibility of the acellular dermal matrix of mature scar tissue and normal skin. METHODS: The acellular dermal matrix was prepared from the human mature scar tissue and the normal skin around the scar. Subsequently, histological and scanning electron microscope observations were performed, and biomechanical properties were detected using universal tensile testing machine. Then, the acellular dermal matrix from mature scar tissue and normal skin was co-cultured with fibroblasts for 10 days, respectively, and the cell growth curve was drawn. Additionally, the acellular dermal matrix from mature scar tissue and normal skin was subcutaneously implanted into the dorsal tissue of Sprague-Dawley rats, respectively and histological observation was conducted at 4, 8 and 12 weeks after implantation. RESULTS AND CONCLUSION: There were many gaps but no cellular components in the acellular dermal matrix, in both two groups. Collagen fibers of the acellular dermal matrix derived from mature scar were looser than that of the normal skin, and arranged slightly irregularly; the biomechanical properties of the acellular dermal matrix derived from mature scar were similar to that of the normal skin, which exhibited appropriate flexibility and strength. There was no significant difference in the growth state of the two kinds of acellular dermal matrix, and the growth curve was basically consistent. After 4 weeks of implantation, more inflammatory cells infiltration could be found in the mature scar group, and in contrast, only a few inflammatory cells infiltration appeared in the normal skin group, These inflammatory reactions disappeared with time in both two groups. Besides, collagen fibers arranged in neat, and small vessels grew into the implants in both two groups. In conclusion, the tissue structure, biomechanical properties and biocompatibility of the acellular dermal matrix derived from scar tissue are almost consistent with those of the human normal skin.     

兔骨髓间充质干细胞向尿路上皮分化后构建膀胱组织工程化移植物

背景：尿路上皮细胞是泌尿系组织工程领域重要的种子细胞,但是难以体外大量扩增;有研究表明骨髓间充质干细胞可以向尿路上皮细胞分化,但关于分化后细胞在植入动物体内后上皮生成情况,以及分化后细胞在组织工程领域的具体应用研究尚不多。 目的：分离、扩增兔骨髓间充质干细胞,诱导骨髓间充质干细胞向尿路上皮细胞分化并与兔膀胱脱细胞基质构建组织工程化移植物,了解分化后细胞作为种子细胞的效果。 方法：12只8周龄雄性新西兰大白兔胫骨穿刺,抽取骨髓,密度梯度离心法分离骨髓间充质干细胞,第4或5代细胞以条件培养基培养2周,进行分化后细胞的鉴定。随后将分化后细胞种植在膀胱脱细胞基质上构建组织工程化移植物,进行膀胱修补;另12只动物作为对照组以尿路上皮细胞与膀胱脱细胞基质构建复合物行膀胱修补。 结果与结论：骨髓间充质干细胞培养成功并在体外扩增,由条件培养基培养诱导分化后,PCR检测提示分化后细胞干细胞标志物CD44表达降低,而上皮细胞标志物UP1a表达升高,行免疫荧光检测发现分化后细胞能表达尿路上皮特异性标志物UP1a,而骨髓间充质干细胞无表达。分化后细胞构建的组织工程化移植物在膀胱修补2周后可形成稳定连续的上皮覆盖,上皮层厚度与尿路上皮细胞构建的组织工程化移植物类似。提示骨髓间充质干细胞向尿路上皮诱导分化后可作为泌尿系组织工程的种子细胞,可能是尿路上皮细胞之外的又一新选择。     

Induction of smooth muscle cell-like phenotype in marrow-derived cells among regenerating urinary bladder smooth muscle cells

Tissue regeneration on acellular matrix grafts has great potential for therapeutic organ reconstruction. However, hollow organs such as the bladder require smooth muscle cell regeneration, the mechanisms of which are not well defined. We investigated the mechanisms by which bone marrow cells participate in smooth muscle formation during urinary bladder regeneration, using in vivo and in vitro model systems. In vivo bone marrow cells expressing green fluorescent protein were transplanted into lethally irradiated rats. Eight weeks following transplantation, bladder domes of the rats were replaced with bladder acellular matrix grafts. Two weeks after operation transplanted marrow cells repopulated the graft, as evidenced by detection of fluorescent staining. By 12 weeks they reconstituted the smooth muscle layer, with native smooth muscle cells (SMC) infiltrating the graft. In vitro, the differential effects of distinct growth factor environments created by either bladder urothelial cells or bladder SMC on phenotypic changes of marrow cells were examined. First, supernatants of cultured bladder cells were used as conditioned media for marrow cells. Second, these conditions were reconstituted with exogenous growth factors. In each case, a growth factor milieu characteristic of SMC induced an SMC-like phenotype in marrow cells, whereas that of urothelial cells failed. These findings suggest that marrow cells differentiate into smooth muscle on acellular matrix grafts in response to the environment created by SMC.     

Naturally occurring scaffolds for soft tissue repair and regeneration

Cell growth supports (i.e., scaffolds) that provide a conducive environment for normal cellular growth, differentiation, and angiogenesis are important components of tissue engineered grafts because rapid integration with the host is essential for long-term graft viability. While many of these scaffold materials are synthetic biodegradable polymers, others are naturally derived from mammalian tissue sources. Naturally occurring scaffold materials include small intestinal submucosa, acellular dermis, amniotic membrane tissue, cadaveric fascia, and the bladder acellular matrix graft. Upon implantation, these materials elicit a host-tissue response that initiates angiogenesis, encourages tissue deposition and culminates in restoration of structure and function specific to the grafted site. The sources, the methods of procurement and processing, and the effects of these naturally occurring materials on angiogenesis and tissue deposition are reviewed.     

Macrophage phenotype and remodeling outcomes in response to biologic scaffolds with and without a cellular component

Recently, macrophages have been characterized as having an M1 or M2 phenotype based on receptor expression, cytokine and effector molecule production, and function. The effects of macrophage phenotype upon tissue remodeling following the implantation of a biomaterial are largely unknown. The objectives of this study were to determine the effects of a cellular component within an implanted extracellular matrix (ECM) scaffold upon macrophage phenotype, and to determine the relationship between macrophage phenotype and tissue remodeling. Partial-thickness defects in the abdominal wall musculature of Sprague–Dawley rats were repaired with autologous body wall tissue, acellular allogeneic rat body wall ECM, xenogeneic pig urinary bladder tissue, or acellular xenogeneic pig urinary bladder ECM. At 3, 7, 14, and 28 days the host tissue response was characterized using histologic, immunohistochemical, and RT-PCR methods. The acellular test articles were shown to elicit a predominantly M2 type response and resulted in constructive remodeling, while those containing a cellular component, even an autologous cellular component, elicited a predominantly M1 type response and resulted in deposition of dense connective tissue and/or scarring. We conclude that the presence of cellular material within an ECM scaffold modulates the phenotype of the macrophages participating in the host response following implantation, and that the phenotype of the macrophages participating in the host response appears to be related to tissue remodeling outcome.     

22 week assessment of bladder acellular matrix as a bladder augmentation material in a porcine model

Previous studies on the reconstruction of porcine bladder using bladder acellular matrix allograft (BAMA) have indicated positive preliminary results with respect to graft shrinkage and cellular repopulation. The current study was conducted to investigate the feasibility of using BAMA in a similar model of bladder reconstruction out to longer time frames (22 weeks). At predetermined time points, the macroscopic, histological and mechanical properties of explanted native and BAMA tissues were evaluated and compared. Macroscopically, contracture of the BAMA was observed. The peripheral regions of the grafts experienced extensive cellular repopulation. Towards the centre however, all grafts were consistently devoid of organized smooth muscle bundles and a well-developed urothelium. An alteration in both the amount and organization of collagen was also observed within this region. Significant differences (p < 0.05) in the rupture strain and the elastic modulus of the BAMA compared to native bladder tissue appear to correlate with macroscopic graft contracture as well as the fibroproliferative tissue response of the matrix.     

人脱细胞真皮基质在乳房切除术后即刻乳房重建术中应用的研究进展

乳房切除术后即刻进行乳房重建术可以重塑乳房的外形,恢复女性第二性征,对患者的心理健康有利,可以增加其作为女性的自信心.人脱细胞异体真皮基质(HADM)是一种同种异体脱细胞真皮基质材料,在乳房切除术后即刻乳房重建术中的应用对术后结果有着积极作用.HADM具有强大的再生能力,能为基于植入物的乳房重建提供牢固的组织支持,改善...