清除骨髓中癌细胞的磁性微球研究I聚苯乙烯磁性微球的研制

为制备能用于清除骨髓中癌细胞的磁性微球，首先合成了单分散、大粒径的多孔聚苯乙烯交联微球，借助微球多孔结构对其进行磁化。探讨了影响磁化效果的主要因素。为使其与单抗连接紧密，在微球表面聚合了一层聚丙烯醛膜，使其表面带上易与单抗反应的醛基。同时测定了所制微球的磁响应性。Ｘ射线衍射证明磁性物质为γＦｅ２Ｏ３。     

单克隆抗体BDI-I导向的阿霉素白蛋白毫微球对人膀胱癌细胞的特异杀伤活性

用化学偶联法将抗人膀胱癌单克隆抗体分子偶联到阿霉素白蛋白毫微球上,构建了一个有靶向杀伤性的免疫毫微球,即:阿霉素白蛋白载单克隆抗体毫微球(ADR-NP-Ab)。改变阿霉素毫微球和单克隆抗体的反应分子比,确定了制备该免疫毫微球的最佳条件。经免疫荧光检测及显微照像分析证明,免疫毫微球可有效地和人膀胱癌细胞结合。体外杀伤试验表明,此免疫毫微球对靶细胞EJ有高度特异杀伤活性,而对无关的人直肠癌Lovo细胞则无明显作用。     

清除骨髓中癌细胞的磁性微球研究 II.聚苯乙烯磁性微球的研制

为制备能用于清除骨髓中癌细胞的磁性微球,首先合成了单分散、大粒径的多孔聚苯乙烯交联微球,借助微球多孔结构对其进行磁化。探讨了影响磁化效果的主要因素。为使其与单抗连接紧密,在微球表面聚合了一层聚丙烯醛膜,使其表面带上易与单抗反应的醛基。同时测定了所制微球的磁响应性。X-射线衍射证明磁性物质为γ-Fe₂O₃。     

单克隆抗体BDI－I导向的阿霉素白蛋白毫微球对人膀胱癌细胞的特异杀伤活性

用化学偶联法将抗人膀胱癌单克隆抗体分子偶联到阿霉素白蛋白毫微球上，构建了一个有靶向杀伤性的免疫毫微球，即：阿霉素白蛋白载单克隆抗体毫微球（ＡＤＲ－ＮＰ－Ａｂ）。改变阿霉素毫微球和单克隆抗体的反应分子比，确定了制备该免疫毫微球的最佳条件。经免疫荧光检测及显微照像分析证明，免疫毫微球可有效地和人膀胱癌细胞结合。体外杀伤试验表明，此免疫毫微球对靶细胞ＥＪ有高度特异杀伤活性，而对无关的人直肠癌Ｌｏｖｏ细胞则无明显作用。     

磁性壳聚糖微球制备及生物相容性的研究

目的:制备5-氟尿嘧啶磁性壳聚糖微球并评价空载磁性壳聚糖微球的生物相容性。方法:采用乳化交联法制备5-氟尿嘧啶磁性壳聚糖微球并优化制备工艺,采用扫描电镜和振动样品磁强计(VSM)对微球进行表征;四噻唑蓝法观察细胞增殖情况,评估磁性壳聚糖微球的体外细胞毒性;溶血实验和血常规检查评估磁性壳聚糖微球的血液相容性;植埋实验评估磁性壳聚糖微球的组织相容性。结果:经过优化后的5-氟尿嘧啶磁性壳聚糖微球包封率和载药量分别为70.2%和12.3%,Z-均粒径为1 479.6 nm,饱和磁化度为4.79 emu.g-1,微球形态良好、均匀圆整;自制空载磁性壳聚糖微球体外细胞相容性符合要求,显示出良好的血液相容性和体内组织相容性。结论:优化了5-氟尿嘧啶磁性壳聚糖微球的制备工艺,制备的空载磁性壳聚糖微球具有很好的生物相容性。     

葡萄球菌蛋白A磁性微球的特异性细胞结合

蛋白A是从金黄色葡萄球菌衍生的一种蛋白质。作者等将此物质结合于磁性白蛋白微球骨架中,由于蛋白A可与大多数亚类免疫球蛋白G(IgG)中的Fc部分结合,产生可以联接针对特定细胞表面抗原的特异性免疫球蛋白,同时,在外界磁场的作用下,这些磁性微球可以聚集于特异的体内部位。本方法不仅避免利用化学耦联剂联接免疫球蛋白作用时间长、纯度要求高的缺点,而且还可利用磁性药物载体和免疫学方法的共同优点提供一条抗癌药物定位给药的新途径。本中详述了蛋白A磁性微球的制备和各种免疫球蛋白抗体与磁性微球的联接方法。利用~(51)Cr对鸡和羊     

阿霉素磁性明胶微球的制备及特性研究

采用乳化－交联技术制备阿霉素磁性明胶微球，并用荧光分光光度法测定磁性微球中的药量。用原子吸收分光光度法测定磁性微球中磁铁粒子的含量。用振动样品磁强计测定磁性微球的磁性。同时测定了微球粒径大小与分布。     

核素标记叶酸偶联白蛋白纳米微球对人卵巢癌细胞生长的影响

目的观察核素标记叶酸靶向白蛋白纳米微球对人卵巢癌细胞生长的影响。方法将体外培养的SKOV3人卵巢癌细胞分为八组:阴性对照组(只加RPMI-1640培养液),单纯化疗组(叶酸偶联载药白蛋白磁性纳米微球,不加磁场),单纯放疗组[188铼(188 Re)标记的叶酸偶联白蛋白磁性纳米微球,不加磁场],单纯热疗组(叶酸偶联白蛋白磁性纳米微球,加磁场),化疗联合放疗组(188 Re标记的叶酸偶联载药白蛋白磁性纳米微球,不加磁场),化疗联合热疗组(叶酸偶联载药白蛋白磁性纳米微球,加磁场),放疗联合热疗组(188 Re标记的叶酸偶联白蛋白磁性纳米微球,加磁场)和热疗、化疗、放疗联合治疗组(联合治疗组,188 Re标记的叶酸偶联载药白蛋白磁性纳米微球,加磁场)。48h后MTT方法测定各组细胞增殖率,流式细胞术测定细胞凋亡率。结果阴性对照组对卵巢癌细胞增殖的抑制作用弱于其他各组,联合治疗组强于其他各组(P<0.05)。单纯热疗组、化疗联合放疗组、化疗联合热疗组、放疗联合热疗组和联合治疗组中细胞周期G1期前出现明显的亚二倍体凋亡峰;阴性对照组、单纯热疗组、化疗联合放疗组、化疗联合热疗组、放疗联合热疗组和联合治疗组的细胞凋亡率分别为0.08%、7.56%、17.14%、21.64%、33.94%和57.16%。结论磁感应热疗、化疗、核素靶向放疗的联合作用能有效抑制人卵巢癌细胞的生长。     

磁性免疫微球在人血清白蛋白纯化中的应用

目的为了快速地从人血清中提纯人血清白蛋白，利用磁性免疫微球作为提取手段，再用间接酶联免疫法测定人血清白蛋白的回收率。方法将经过羧基修饰的聚苯乙烯微球作为载体，用EDC(碳化亚胺)活化微球表面的羧基，再将兔抗人血清白蛋白抗体包被于微球上，这种微球-抗体复合物能特异性地捕获人血清白蛋白，磁分离复合物后，通过将兔抗人血清白蛋白抗体作为捕获抗体，将酶联羊抗人血清白蛋白抗体作为检测抗体，建立起间接酶联免疫法，用于检测人血清中和磁性免疫微球上吸附人血清白蛋白的浓度，得到微球从人血清中提纯人血清白蛋白的回收率。结果第1次提纯的回收率为(86±4)%，重复利用微球2次，回收率分别为(69.0±0.6)%和(40.8±0.8)%，而提纯的人血清白蛋白的纯度为90%。结论以上结果表明，免疫磁性微球提纯人血清白蛋白的实验是有效的，为工业上大规模提纯人血清白蛋白提供了一条新的思路。     

药物导向靶部位研究进展

无论口服或注射用药,药物皆作用于患者整个机体。在对恶性肿瘤进行治疗时,人们只希望药物作用于靶部位(或靶细胞),而对正常细胞无损。但目前使用的抗肿瘤药物却无选择性,它们除能杀灭部分癌细胞外,同时亦杀伤和抑制正常细胞,常使患者机体蒙受很大损伤,甚至难以继续治疗。为克服这一障碍,多年来不少学者对药物如何导向靶部位,进行了大量探索。近10多年来,此项工作已有一些进展,现概述如下。一、磁性微粒应用磁学原理,将铁磁性颗粒包于含药微球或微囊内,用药后借助于体外磁场效应,使     

Patent News: Antimicrobials

This patent describes a novel method whereby C-type retroviral vectors can be used to transduce a specific subset of quiescent cells with a therapeutic gene, within a heterogeneous population. By incorporating a growth factor which binds preferentially to receptors expressed on the target cells into the retroviral envelope protein or particle, the virions will bind selectively to the cells. Signalling through the engaged receptor will then promote cell division, which is required for a productive infection by the C-type vector to occur. This strategy therefore incorporates cell targeting at the level both of surface binding and receptor signalling in order to lead to transduction of specific cell populations either in vivo or in vitro. The invention has immediate application to gene therapy for diseases wherein transduction of haematopoietic stem cells is required for long-term expression of therapeutic genes (e.g., adenosine deaminase (ADA) deficiency in severe combined immunodeficiency or multidrug resistance gene (MDR) expression in cancer patients to improve bone marrow resistance to chemotherapy treatments). It may, however, be applicable for the transduction of any cell population for which a selective ligand is known and which can transmit a growth stimulatory signal following ligand binding.     

刺梨汁对骨髓抑制小鼠造血功能的调控作用

目的探讨刺梨汁对环磷酰胺合并60Co致骨髓抑制小鼠造血功能的影响,研究其促进血细胞上调的作用机制。方法双抗体夹心法检测外周血常规、骨髓基质中红细胞生成素（EPO）、血小板生成素（TPO）、粒细胞生长因子（GCSF）的量。结果刺梨汁能明显改善骨髓抑制小鼠外周血常规,能有效平衡微环境中TPO的量,改善EPO的表达,对骨髓抑制小鼠骨髓细胞上清中GCSF有明显的正调控作用。结论刺梨汁能提高骨髓抑制小鼠外周血血细胞和骨髓有核细胞计数,可促进骨髓抑制小鼠骨髓细胞从G0/G1期进入增殖周期,并能有效调节骨髓微环境中TPO、EPO、GCSF的表达,从而促进骨髓抑制小鼠的造血功能,可作为一种治疗贫血的辅助保健药物。     

单克隆抗体与博来霉素A6偶联物对肝癌的实验研究

用Dextran T40为中介体的方法偶联抗人肝癌单抗Hlll和博来霉素A6,体外实验显示Hlll与A6偶联物对人肝癌细胞抑制90%克隆生成浓度(IC₉₀)为0.17μmol/L:游离A6以及无关抗体与A6偶联物M3-A6分别为17/μmol/L和7μmol/L;同时加入Hlll单抗明显降低Hill-A6偶联物的细胞毒性;体内实验证明:Hlll-A6偶联物对裸鼠移植的人肝癌抑制率达78%,等剂量A6,M3-A6偶联物和Hlll与A6混合物的抑制率均约为30%。结果表明单抗Hlll与A6偶联物对肝癌的抑制作用明显比游离A6强。     

Neurokinin receptors as potential targets in breast cancer treatment

Despite recent advances in the diagnoses and treatment of breast cancer, this disease continues to be a major cause of death. One of the biggest challenges in breast cancer treatment is bone metastasis. Breast cancer cells (BCCs) are capable of migrating to the bone marrow and utilizing the marrow microenvironment to remain quiescent. While exhibiting quiescence in the marrow, BCCs can evade the effects of conventional cancer treatments such as chemotherapy. Therefore, scientists must find a new paradigm to target these quiescent BCCs. The development of potential targets may require a more comprehensive understanding of the marrow microenvironment and its regulators. The preprotachykinin-1 (PPT-I) gene encodes for the tachykinin peptides, which interact with neurokinin (NK) receptors. Studies have correlated this interaction with BCC integration into the bone marrow and breast cancer progression. In this review, we discuss the roles that different factors of the marrow microenvironment play in breast cancer and targets of NK receptors as potential treatment options.     

刺梨汁对骨髓抑制小鼠造血功能的调控作用

目的 探讨刺梨汁对环磷酰胺合并⁶⁰Co致骨髓抑制小鼠造血功能的影响,研究其促进血细胞上调的作用机制。方法 双抗体夹心法检测外周血象、骨髓基质中红细胞生成素（EPO）、血小板生成素（TPO）、粒细胞生长因子（GCSF）的量。结果 刺梨汁能明显改善骨髓抑制小鼠外周血象;能有效平衡微环境中TPO的量;改善EPO的表达;对骨髓抑制小鼠骨髓细胞上清中GCSF有明显的正调控作用。结论 刺梨汁能提高骨髓抑制小鼠外周血血细胞和骨髓有核细胞计数;可促进骨髓抑制小鼠骨髓细胞从G₀/G₁期进入增殖周期;并能有效调节骨髓微环境中TPO、EPO、GCSF的表达,从而促进骨髓抑制小鼠的造血功能,可作为一种治疗贫血的辅助保健药物。     

Mouse L1210V leukemia as a model to analyse efficiency of leukemic cell elimination by immunotoxin, antibody and complement, and cytostatic agents

In an attempt to eliminate selectively mouse L1210V leukemic cells from infiltrated bone marrow, the immunotoxin MoAb-16-RTA composed of monoclonal antibody recognizing oncofetal antigen on L1210V cells and the ricin A chain was prepared. The immunotoxin exhibited an antigen-specific, dose-dependent cytotoxic effect in vitro. One hour's exposure of leukemic cells to 10(-6) M of immunotoxin appeared to be sufficient to kill all leukemic cells. In the experimental conditions applied, a complete elimination of L1210V cells from leukemic bone marrow was achieved. MoAb-16 antibody and complement in the same experimental protocol, the bone marrow purging was not complete. The surviving leukemic cells were still able to grow and kill recipient mice. The in vitro exposure to immunotoxin or to antibody and complement was not toxic to normal bone marrow progenitors. The exposure of leukemic cells to selected cytostatic agents of the oxazaphosphorine group appeared to be effective in the elimination of leukemic cells, but doses required for killing leukemic cells were highly toxic to normal bone marrow progenitors.     

Alterations in the morphology and functional activity of bone marrow phagocytes following benzene treatment of mice.

Benzene is a well-established hematotoxin that affects developing leukocytes and erythrocytes as well as bone marrow stromal cells. In the present studies we analyzed the effects of benzene on the morphology and functional activity of bone marrow phagocytes. Male Balb/c mice were treated with benzene (660 mg/kg) once per day for 3 days. Bone marrow cells were then isolated and fractionated by density gradient centrifugation. Using highly sensitive techniques in flow cytometry/cell sorting, we found that we could separate three distinct populations of bone marrow cells that differed with respect to size and density. Monoclonal antibody binding and cell sorting revealed a large, dense population that consisted predominantly of granulocytes, a smaller, less dense population of lymphocytes, and a population of intermediate size and density consisting of mononuclear phagocytes and precursor cells. Differential staining of sorted mononuclear phagocytes revealed that benzene treatment of mice caused a marked increase in the number of mature, morphologically activated macrophages in the bone marrow. Benzene treatment of mice also resulted in enhanced chemotaxis and production of hydrogen peroxide by bone marrow granulocytes and mononuclear phagocytes. In contrast, treatment of mice with the combination of hydroquinone and phenol (50 mg/kg each, 1 x/day, 3 days), two metabolites of benzene, resulted in a significant (p < or = 0.02) depression of granulocyte chemotaxis and had no effect on hydrogen peroxide production by bone marrow phagocytes compared to cells from control animals. Taken together these results demonstrate that benzene causes increased differentiation and/or activation of phagocytes in the bone marrow.