Patterson Thomas E, Boehm Cynthia, Nakamoto Chizu, Rozic Richard, Walker Esteban, Piuzzi Nicolas S, Muschler George F
1Departments of Orthopaedic Surgery (T.E.P., N.S.P., and G.F.M.) and Biomedical Engineering (T.E.P., C.B., C.N., R.R., E.W., N.S.P., and G.F.M.), Cleveland Clinic, Cleveland, Ohio.
J Bone Joint Surg Am. 2017 Oct 4;99(19):1673-1682. doi: 10.2106/JBJS.17.00094.
The rational design and optimization of tissue engineering strategies for cell-based therapy requires a baseline understanding of the concentration and prevalence of osteogenic progenitor cell populations in the source tissues. The aim of this study was to (1) define the efficiency of, and variation among individuals in, bone marrow aspiration as a means of osteogenic connective tissue progenitor (CTP-O) harvest compared with harvest from iliac cancellous bone, and (2) determine the location of CTP-Os within native cancellous bone and their distribution between the marrow-space and trabecular-surface tissue compartments.
Eight 2-mL bone marrow aspiration (BMA) samples and one 7-mm transcortical biopsy sample were obtained from the anterior iliac crest of 33 human subjects. Two cell populations were obtained from the iliac cancellous bone (ICB) sample. The ICB sample was placed into αMEM (alpha-minimal essential medium) with antibiotic-antimycotic and minced into small pieces (1 to 2 mm in diameter) with a sharp osteotome. Cells that could be mechanically disassociated from the ICB sample were defined as marrow-space (IC-MS) cells, and cells that were disassociated only after enzymatic digestion were defined as trabecular-surface (IC-TS) cells. The 3 sources of bone and marrow-derived cells were compared on the basis of cellularity and the concentration and prevalence of CTP-Os through colony-forming unit (CFU) analysis.
Large variation was seen among patients with respect to cell and CTP-O yield from the IC-MS, IC-TS, and BMA samples and in the relative distribution of CTP-Os between the IC-MS and IC-TS fractions. The CTP-O prevalence was highest in the IC-TS fraction, which was 11.4-fold greater than in the IC-MS fraction (p < 0.0001) and 1.7-fold greater than in the BMA fraction. However, the median concentration of CTP-Os in the ICB (combining MS and TS fractions) was only 3.04 ± 1.1-fold greater than that in BMA (4,265 compared with 1,402 CTP/mL; p = 0.00004).
Bone marrow aspiration of a 2-mL volume at a given needle site is an effective means of harvesting CTP-Os, albeit diluted with peripheral blood. However, the median concentration of CTP-Os is 3-fold less than from native iliac cancellous bone. The distribution of CTP-Os between the IC-MS and IC-TS fractions varies widely among patients.
Bone marrow aspiration is an effective means of harvesting CTP-Os but is associated with dilution with peripheral blood. Overall, we found that 63.5% of all CTP-Os within iliac cancellous bone resided on the trabecular surface; however, 48% of the patients had more CTP-Os contributed by the IC-MS than the IC-TS fraction.
基于细胞的治疗的组织工程策略的合理设计与优化需要对源组织中成骨祖细胞群体的浓度和患病率有一个基线了解。本研究的目的是：（1）确定与从髂骨松质骨获取相比，骨髓抽吸作为获取成骨结缔组织祖细胞（CTP-O）的一种方法的效率以及个体间的差异；（2）确定CTP-O在天然松质骨内的位置及其在骨髓腔和小梁表面组织区室之间的分布。
从33名人类受试者的髂前嵴获取8份2 mL骨髓抽吸（BMA）样本和1份7 mm经皮质骨活检样本。从髂骨松质骨（ICB）样本中获得两个细胞群体。将ICB样本置于含抗生素-抗真菌剂的αMEM（α-最低必需培养基）中，并用锋利的骨刀切成小块（直径1至2 mm）。可从ICB样本中机械分离的细胞定义为骨髓腔（IC-MS）细胞，仅在酶消化后分离的细胞定义为小梁表面（IC-TS）细胞。通过集落形成单位（CFU）分析，比较了3种骨和骨髓来源细胞在细胞数量以及CTP-O的浓度和患病率方面的差异。
患者之间在IC-MS、IC-TS和BMA样本的细胞及CTP-O产量以及CTP-O在IC-MS和IC-TS组分之间的相对分布方面存在很大差异。CTP-O患病率在IC-TS组分中最高，比IC-MS组分高11.4倍（p < 0.0001），比BMA组分高1.7倍。然而，ICB（合并MS和TS组分）中CTP-O的中位数浓度仅比BMA高3.04±1.1倍（分别为4265个CTP/mL和1402个CTP/mL；p = 0.00004）。
在给定针位点抽取2 mL骨髓是获取CTP-O的有效方法，尽管会被外周血稀释。然而，CTP-O的中位数浓度比天然髂骨松质骨低3倍。CTP-O在IC-MS和IC-TS组分之间的分布在患者之间差异很大。
骨髓抽吸是获取CTP-O的有效方法，但与外周血稀释有关。总体而言，我们发现髂骨松质骨内所有CTP-O的63.5%位于小梁表面；然而，48%的患者IC-MS贡献的CTP-O比IC-TS组分更多。
