Mitochondrial targeting liposomes incorporating daunorubicin and quinacrine for treatment of relapsed breast cancer arising from cancer stem cells

Breast cancer stem cells play a crucial role in the relapse of breast cancers because they are resistant to a standard chemotherapy and the residual cancer stem cells are able to proliferate indefinitely. The objectives of present study were to construct a kind of mitochondrial targeting daunorubicin plus quinacrine liposomes for treating and for preventing the recurrence of breast cancer arising from the cancer stem cells. MCF-7 cancer stem cells were identified as CD44⁺/CD24⁻ cells and cultured in free-serum medium. Evaluations were performed on MCF-7 cancer stem cells, MCF-7 cancer stem cell mammospheres, and the relapsed tumor by xenografting MCF-7 cancer stem cells into female NOD/SCID mice. The particle size of mitochondrial targeting daunorubicin plus quinacrine liposomes was approximately 98 nm. The mitochondrial targeting liposomes evidently increased the mitochondrial uptake of drugs, were selectively accumulated into mitochondria, activated the pro-apoptotic Bax protein, dissipated the mitochondrial membrane potential, opened the mitochondrial permeability transition pores, released cytochrome C by translocation, and initiated a cascade of caspase 9 and 3 reactions, thereby inducing apoptosis of MCF-7 cancer stem cells. The mitochondrial targeting liposomes showed the strongest efficacy in treating MCF-7 cancer cells in vitro, in treating MCF-7 cancer stem cells in vitro, and in treating the relapsed tumor in mice. Mitochondrial targeting daunorubicin plus quinacrine liposomes would provide a new strategy for treating and preventing the relapse of breast cancers arising from cancer stem cells.     

Physicochemical and biological aspects of macrophage-mediated drug targeting in anti-microbial therapy

Macrophages are important drug targets as they mediate a wide variety of infectious diseases. Visceral leishmaniasis (VL), schistosomiasis, brucellosis, and salmonellosis are some of the well-known infectious diseases in which macrophages play a prominent pathophysiological role. For instance, VL parasites exclusively house in the macrophages of liver and spleen. They are resistant to lysosomal degradation by unknown mechanisms, they survive and thrive safely within macrophages, they multiply, and they ultimately affect visceral organs, leading to severe pathological and sometimes even fatal conditions. The majority of routinely used drugs administered in free form distribute all over the body via systemic circulation, leading to relatively low therapeutic activity and a certain degree of toxicity. Unlike for nonmicrobial diseases, targeting parasites procuring resistance and ineffective therapeutic outcome can be obviously speculated in case of infectious disease. The preferential uptake by macrophages, intended to improve the balance between efficacy and toxicity, can be achieved by the use of nanomedicines, i.e. submicron-sized macromolecular or particulate drug delivery systems. This insight has stimulated researchers to use nanomedicines--which tend to be recognized by macrophages as 'foreign' and consequently are taken up by the intended target cells much more effectively than their free drug counterparts--to improve the treatment of infectious diseases. The literature reports extensively on such approaches; however, there are several constraints that limit the application of nanomedicine in macrophage-mediated drug targeting. Here, we briefly describe the strategies that are used to achieve effective drug targeting to macrophages, using VL as a model disease, and we also put forth an understanding of the most important limiting factors. Various physicochemical and biological factors used by researchers as reported in the literature are addressed, and the most important mechanisms and modes by which macrophage-specific drug targeting can be achieved are summarized. Based on the evidence obtained to date, it can be concluded that targeting macrophages is a valuable and validated strategy for improving the treatment of infectious diseases.     

Curcumin-loaded PLGA Nanoparticles Conjugated with Anti-P-glycoprotein Antibody to Overcome Multidrug Resistance

Background: The encapsulation of curcumin (Cur) in polylactic-co-glycolic acid (PLGA) nanoparticles (Cur-NPs) was designed to improve its solubility and stability. Conjugation of the Cur-NPs with anti-P-glycoprotein(P-gp) antibody (Cur-NPs-APgp) may increase their targeting to P-gp, which is highly expressed in multidrugresistance(MDR) cancer cells. This study determined whether Cur-NPs-APgp could overcome MDR in a humancervical cancer model (KB-V1 cells) in vitro and in vivo. Materials and Methods: First, we determined the MDRreversingproperty of Cur in P-gp-overexpressing KB-V1 cells in vitro and in vivo. Cur-NPs and Cur-NPs-APgp,in the range 150-180 nm, were constructed and subjected to an in vivo pharmacokinetic study compared withCur. The in vitro and in vivo MDR-reversing properties of Cur-NPs and Cur-NPs-APgp were then investigated.Moreover, the stability of the NPs was determined in various solutions. Results: The combined treatment ofpaclitaxel (PTX) with Cur dramatically decreased cell viability and tumor growth compared to PTX treatmentalone. After intravenous injection, Cur-NPs-APgp and Cur-NPs could be detected in the serum up to 60 and 120min later, respectively, whereas Cur was not detected after 30 min. Pretreatment with Cur-NPs-APgp, but notwith NPs or Cur-NPs, could enhance PTX sensitivity both in vitro and in vivo. The constructed NPs remaineda consistent size, proving their stability in various solutions. Conclusions: Our functional Cur-NPs-APgp maybe a suitable candidate for application in a drug delivery system for overcoming drug resistance. The furtherdevelopment of Cur-NPs-APgp may be beneficial to cancer patients by leading to its use as either as a MDRmodulator or as an anticancer drug.     

肺部缓释微球治疗肺部疾病的性能及评价

背景：肺部因其特殊的生理结构而适合作为局部或全身用药的给药部位,而肺部缓释微球在肺部局部疾病治疗乃至全身疾病治疗方面的优越性尚缺乏更多的报道。 目的：评价肺部缓释微球载体材料的释药性能以及临床给药途径的安全性,对比肺部缓释微球与其他肺部给药剂型的差异。 方法：观察微球在肺部的分布及降解情况、肺组织的病理变化和连续给药对肺功能的影响。 结果与结论：肺部缓释微球常用的材料有淀粉、聚乳酸等,具有生物可降解性、生物相容性和生物黏附性,并且缓释微球制备简单,对正常组织无损伤,安全性高,肺部缓释微球在体内有良好的肺靶向性,可提高药物的疗效,降低药物毒副作用,对肺组织无病理性损伤。     

TAT-N24穿膜融合多肽对前列腺癌细胞增殖的影响

目的 观察TAT-N24穿膜融合多肽抑制前列癌细胞增殖的作用. 方法 用纯化的TAT-N24穿膜融合多肽处理前列癌PC3细胞,采用流式细胞仪检测细胞周期进程的改变, BrdU掺入法检测其对细胞DNA合成的影响,Western blot法检测细胞内AKT蛋白的磷酸水平的变化. 结果 ①细胞周期分布:空白组G₀/G₁期(56.9±6.1)%,S期(27.0±2.3)%,G₂/M期(16.1±1.3)%;对照多肽组G₀/G₁期(57.9±4.8)%,S期(24.2±3.1)%,G₂/M期(27.8±1.4)%;TAT-N24组G0/G1期(68.6±5.4)%(P<0.05),S期(19.4±1.5)%(P<0.05),G₂/M期(12.3±1.4)%.②BrdU阳性细胞为空白组(37.9±3.2)%,对照多肽组(36.2±4.1)%,TAT-N24组(21.5±2.4)% (P<0.05) ;③AKT磷酸化水平组间差异无统计学意义. 结论 TAT-N24穿膜融合多肽能有效阻滞前列腺癌PC3细胞的细胞周期进程,并抑制其DNA合成.TAT-N24穿膜融合多肽有望成为有效的治疗前列腺癌的分子靶向药物.     

Consequences of Late-Stage Non–Small-Cell Lung Cancer Cachexia on Muscle Metabolic Processes

Introduction

The loss of muscle is common in patients with advanced non–small-cell lung cancer (NSCLC) and contributes to the high morbidity and mortality of this group. The exact mechanisms behind the muscle loss are unclear.

新型羧甲基壳聚糖包裹C-藻蓝蛋白负载CD59配体的靶向纳米微球的制备及其对HeLa细胞的杀伤作用

目的：制备一种新型的C-藻蓝蛋白（C-phycocyanin,C-PC）靶向纳米微球（nanometer microspheres,NPs）,并探究其对HeLa细胞的靶向治疗作用。方法：采用离子交联法制备靶向羧甲基壳聚糖（carboxymethyl chitosan,CMC ）纳米载药颗粒C-PC/CMC-NPs;响应面优化法筛选出最佳制备条件,并用透射电镜、激光粒度仪观察纳米载药颗粒的表征;MTT法检测靶向纳米颗粒C-PC/CMC-CD59sp-NPs对人宫颈癌HeLa细胞生长的影响;溶血实验检测C-PC/CMC-CD59sp-NPs的组织相容性及安全性;Western blotting和免疫组化法分别检测C-PC/CMC-CD59sp-NPs 对HeLa细胞内活化的Caspase-3/PARP蛋白和Bcl-2蛋白表达的影响。结果： 成功制备C-PC/CMC纳米微球,透射电镜观察到纳米微球呈现出规则的球形,分散均匀,其粒径约为160 nm。最佳制备条件：羧甲基壳聚糖浓度为2.0 mg/ml,CaCl2浓度为1.0 mg/ml,粒径约为120 nm的球形,包封率为(62±5)%;CMC与C-PC投药量为3∶1,载药量为(20±3)%;C-PC/CMC-NPs体外表现出缓释特征,在120 h内pH=5.4和74条件下,释放率分别达到80%和60%;同时未出现溶血现象。C-PC/CMC-CD59sp-NPs对HeLa细胞增殖有明显的抑制作用,促进活化的Caspase-3/PARP蛋白的表达,抑制Bcl-2蛋白的表达（均P＜0.05）。结论：新型靶向纳米药物C-PC/CMC-CD59sp-NPs能在体外抑制HeLa细胞的生长,诱导其凋亡。为海洋药物的研发提供了新的思路,对靶向纳米药物的进一步研究提供理论基础。     

Tumor-derived exosomes: Nanovesicles made by cancer cells to promote cancer metastasis

Nanomedicine usually refers to nanoparticles that deliver the functional drugs and siRNAs to treat cancer. Recent research has suggested that cancer cells can also make nanoparticles that also deliver functional molecules in promoting cancer metastasis, which is the leading cause of various cancer mortalities. This nanoparticle is called tumor-derived vesicles, or better-known as tumor-derived exosomes (TEXs). TEXs are nanoscale membrane vesicles (30–140 nm) that are released continuously by various types of cancer cells and contain tumor-derived functional biomolecules, including lipids, proteins, and genetic molecules. These endogenous TEXs can interact with host immune cells and epithelial cells locally and systemically. More importantly, they can reprogram the recipient cells in favor of promoting metastasis through facilitating tumor cell local invasion, intravasation, immune evasion, extravasation, and survival and growth in distant organs. Growing evidence suggests that TEXs play a key role in cancer metastasis. Here, we will review the most recent findings of how cancer cells harness TEXs to promote cancer metastasis through modulating vascular permeability, suppressing systemic immune surveillance, and creating metastatic niches. We will also summarize recent research in targeting TEXs to treat cancer metastasis.     

Comparison of adenovirus fiber, protein IX, and hexon capsomeres as scaffolds for vector purification and cell targeting

The direct genetic modification of adenoviral capsid proteins with new ligands is an attractive means to confer targeted tropism to adenoviral vectors. Although several capsid proteins have been reported to tolerate the genetic fusion of foreign peptides and proteins, direct comparison of cell targeting efficiencies through the different capsomeres has been lacking. Likewise, direct comparison of with one or multiple ligands has not been performed due to a lack of capsid-compatible ligands available for retargeting. Here we utilize a panel of metabolically biotinylated Ad vectors to directly compare targeted transduction through the fiber, protein IX, and hexon capsomeres using a variety of biotinylated ligands including antibodies, transferrin, EGF, and cholera toxin B. These results clearly demonstrate that cell targeting with a variety of high affinity receptor-binding ligands is only effective when transduction is redirected through the fiber protein. In contrast, protein IX and hexon-mediated targeting by the same set of ligands failed to mediate robust vector targeting, perhaps due to aberrant trafficking at the cell surface or inside targeted cells. These data suggest that vector targeting by genetic incorporation of high affinity ligands will likely be most efficient through modification of the adenovirus fiber rather than the protein IX and hexon capsomeres. In contrast, single-step monomeric avidin affinity purification of Ad vectors using the metabolic biotinylation system is most effective through capsomeres like protein IX and hexon.