心肌梗死是由冠状动脉阻塞所引起的心肌缺氧坏死,其发病率和病死率居高不下。近年研究发现,利用组织工程手段仿生构建心肌微环境能有效改善心肌梗死区微环境,对心肌的再生能力有着重要的调控作用,能在一定程度上促进心肌再生,有望成为将来治疗心肌梗死的新方向。然而,由于对仿生心肌微环境和机体微环境交互作用、引发的生物学效应及作用机制不清楚,直接影响心肌损伤修复的过程和质量。因此,阐明仿生心肌微环境在心肌损伤修复过程中的交互作用过程及其介导的生物学效应迫在眉睫。该文系统性综述了仿生心肌微环境的构建策略及植入体内后介导的生物学效应,包括免疫调控效应、促血管再生效应以及再生协同效应等,为新型心肌补片的仿生设计和临床应用提供理论支持。

Myocardial infarction（MI）,arising from coronary artery obstruction resulting in hypoxic necrosis of myocardium,remains high morbidity and mortality．Recent studies have revealed that constructing myocardial microenvironment bionically through tissue engineering methods can effectively ameliorate the microenvironment in the infarcted area and exert a crucial regulatory role in myocardial regeneration,which promotes myocardial regeneration to a certain extent and holds promise for the treatment of MI．However,the interaction between biomimetic myocardial microenvironment and host microenvironment,as well as the triggered biological effects and mechanisms are not clear,which directly affects the process and quality of myocardial repair．Therefore,it is urgent to clarify the interaction process and biological effects mediated by the biomimetic myocardial microenvironment during myocardial repair．This review systematically summarizes the construction strategies of biomimetic myocardial microenvironment and their mediated biological effects after implantation,including immunomodulatory effects,pro-vascular regenerative effects,and regenerative synergistic effects,which provides theoretical support for the biomimetic design and clinical application of novel cardiac patches．

目的 探索内源性神经干细胞在大鼠海马可溶性因子中的体外发育归宿及分化鉴定。方法 显微镜下分离Wistar大鼠海马组织放置于低温DMEM/12培养基,低温振荡2小时后高速离心(15000 g),获取实验所用海马组织可溶性因子。取材出生1天的Wistar乳鼠海马中的内源性神经干细胞(endogenous neural stem cells, ENSCs),将ENSCs分别于含海马可溶性因子终浓度为0(对照组)、50、100、200、400 μl/mL的无血清DMEM/F12培养基中培养6天并每日观察,使用免疫细胞化学、Western Blot印记技术比较各组ENSCs中Nestin、CD133的表达量;同时计量并比较各组ENSCs成球个数,以探索在模拟颅内微环境情况下,ENSCs发育、归宿及分化。进一步于最适宜的海马可溶性因子终浓度中分化神经球,对分化的细胞行神经元特异性蛋白入(如:β-tubullin III、MAP2)及胶质细胞特异性蛋白(如:GFAP、S100及p75 NGFR)免疫细胞化学检测。结果 大鼠ENSCs在培养基中呈单细胞漂浮生长,球形; ENSCs于海马可溶性因子各实验分组中培养第2天呈细胞球状态,对照组中无细胞球形成(与100 μl/mL组比较,P₁=0.00),100 μl/mL组与对照组比较有统计学意义(P₁=0.00<0.05);至第6天,在100 μl/mL组中的细胞球数量明显多于其余各组(P₁'=P₂'=P₃'=P₄'=0.00)。在免疫细胞化学检测中,100 μl/mL组中细胞球表达干细胞高亲和蛋白Nestin、CD133阳性,Western Blot免疫印迹检测其中Nestin、CD133蛋白高于对照组。进一步分化试验中,细胞球呈贴壁生长的单细胞状态、有突起伸出、长梭形,免疫细胞化学检测分化的细胞表达胶质细胞特异性蛋白GFAP、S100、p75NGFR阳性,但不表达神经元特异性蛋白β-tubullin III与MAP2。结论 大鼠ENSCs在终浓度为100 μl/mL的HSF作用下,可促进 ENSCs的增殖分裂;ENSCs在同样浓度下的HSF中可进一步分化为表达GFAP、S100、p75NGFR阳性的胶质样细胞;100 μl/mL的HSFS是ENSCs的一种生理性诱导剂或参与促进ENSCs增殖、分化及通过细胞替代或因子分泌等机制修复神经损伤。

Objective The aim of this study was to explore induction and differentiation of endogenous neural stem cells(ENSCs) in the hippocampus soluble factors(HSF) from the hippocampus of adult Wistar rats by mimicking an intracranial microenvironment. Methods After Wistar rats sacrificed, the hippocampus tissue was obtained in cold DMEM/F12. After centrigued and filtered, the HSF was stored at -20℃. The ENSCs was obtained from the hippocampus tissue of a neonate Wistar rat. Collected the tissue, digested and obtained the ENSCs. After we observed the morphology, the ENSCs were cultured in different concentration (0、50、100、200、400 μl/mL) of HSF for 6 days, and compared the expression of Nestin and CD133 by immunocytochemistry. Meanwhile,we compared the Nestin and CD133 protein by western blot. And then we explored the optimal concentration of HSF by the numbers of all groups on the second and sixth day. Furthermore, we did the differentiated experiment using the same concentration of HSF. Results The number of neurospheres in the 100 μg/mL group was significantly higher than those in the other groups on the 6th day. Immunofluorescence revealed that the neurospheres from ENSCs in the 100 μg/mL group more highly expressed nestin and CD133 than control. This result was confirmed by western blot analysis. The neurospheres can differentiate into glia-like cells in 100 μg/mL HSF and 1% FBS expressing GFAP, S100 and P75 NGFR by immunofluorescence. Conclusion These data indicated that HSF alone, mimicking a destination of ENSCs in vitro, could induce and differentiate neurospheres from ENSCs, as a new method to get NSCs and glia-like cells differentiated from ENCs to repair the diseases of center nervous system.

与正常组织细胞微环境相比,肿瘤微环境具有一定的异质性,包括偏酸性、氧化还原状态失衡、存在高浓度活性氧以及酶过量表达等。根据以上肿瘤微环境特点,可设计出一系列通过各种特殊微环境响应型连接臂相连的小分子或聚合物前药纳米粒。其中,多柔比星阿霉素作为一类最常见的广谱抗肿瘤药物在治疗肿瘤的过程中发挥重要作用。文章探讨了在肿瘤微环境特异性的生理状态下针对不同微环境所设计的多柔比星前药及其释放特性等,归纳总结了肿瘤微环境响应型多柔比星前药的研究进展。

Compared with normal tissue cell microenvironment, there is some differences in tumor microenvironment, such as partial acidity, imbalance of redox state, high concentration of reactive oxygen species and cathepsin. According to the above characteristics of tumor microenvironment, a series of small molecule or polymer prodrug nanoparticles connected by various special microenvironment responsive structures can be designed. Doxorubicin, as one of the most common broad-spectrum antitumor drugs, plays an important role in the treatment of tumors. This review discusses the doxorubicin prodrug designed for different tumor microenvironments under the physiological state of tumor microenvironment specificity and their release characteristics, and summarizes the research progress of tumor microenvironment-responsive doxorubicin prodrug.