School of Biomedical Engineering, Amit Chakma Engineering Building, The University of Western Ontario, London, Ontario, Canada, N6A 5B9; Krembil Centre for Stem Cell Biology, Molecular Medicine Research Laboratories, Robarts Research Institute, London, Ontario, N6A 5B6, Canada.
Krembil Centre for Stem Cell Biology, Molecular Medicine Research Laboratories, Robarts Research Institute, London, Ontario, N6A 5B6, Canada; Don Rix Protein Identification Facility, Department of Biochemistry, University of Western Ontario, London, Ontario, N6G 2V4, Canada.
Biomaterials. 2021 Jul;274:120867. doi: 10.1016/j.biomaterials.2021.120867. Epub 2021 May 8.
Cellular therapies to stimulate therapeutic angiogenesis in individuals with critical limb ischemia (CLI) remain under intense investigation. In this context, the efficacy of cell therapy is dependent on the survival, biodistribution, and pro-angiogenic paracrine signaling of the cells transplanted. Hematopoietic progenitor cells (HPC) purified from human umbilical cord blood using high aldehyde dehydrogenase-activity (ALDH cells) and expanded ex vivo, represent a heterogeneous mixture of progenitor cells previously shown to support limb revascularization in mouse models of CLI. The objectives of this study were to investigate the utility of bioscaffolds derived from human decellularized adipose tissue (DAT) to guide the differentiation of seeded HPC in vitro and harness the pro-angiogenic capacity of HPC at the site of ischemia after implantation in vivo. Probing whether the DAT scaffolds altered HPC differentiation, label-free quantitative mass spectrometry and flow cytometric phenotype analyses indicated that culturing the HPC on the DAT scaffolds supported their differentiation towards the pro-angiogenic monocyte/macrophage lineage at the expense of megakaryopoiesis. Moreover, implantation of HPC in DAT scaffolds within a unilateral hindlimb ischemia model in NOD/SCID mice increased cell retention at the site of ischemia relative to intramuscular injection, and accelerated the recovery of limb perfusion, improved functional limb use and augmented CD31 capillary density when compared to DAT implantation alone or saline-injected controls. Collectively, these data indicate that cell-instructive DAT scaffolds can direct therapeutic HPC differentiation towards the monocyte/macrophage lineage and represent a promising delivery platform for improving the efficacy of cell therapies for CLI.
细胞疗法可刺激患有严重肢体缺血（CLI）的个体的治疗性血管生成，目前仍在深入研究中。在这种情况下，细胞疗法的疗效取决于移植细胞的存活、生物分布和促血管生成旁分泌信号。使用高醛脱氢酶活性（ALDH 细胞）从人脐血中纯化的造血祖细胞（HPC）并在体外扩增，代表了以前在 CLI 小鼠模型中支持肢体再血管化的祖细胞的异质混合物。本研究的目的是研究源自人去细胞脂肪组织（DAT）的生物支架在体外指导接种 HPC 分化的效用，并利用 HPC 在体内植入缺血部位的促血管生成能力。研究是否 DAT 支架改变了 HPC 的分化，无标记定量质谱和流式细胞表型分析表明，在 DAT 支架上培养 HPC 支持其向促血管生成的单核细胞/巨噬细胞谱系分化，而牺牲巨核细胞生成。此外，将 HPC 植入 NOD/SCID 小鼠单侧后肢缺血模型中的 DAT 支架内，与肌肉内注射相比，可增加缺血部位的细胞保留率，并加速肢体灌注的恢复、改善功能性肢体使用和增加 CD31 毛细血管密度，与 DAT 单独植入或盐水注射对照相比。总的来说，这些数据表明，细胞指导的 DAT 支架可以将治疗性 HPC 分化为单核细胞/巨噬细胞谱系，并代表改善 CLI 细胞治疗效果的有前途的递送平台。
