Nanotechnology for colorectal cancer detection and treatment

Colorectal cancer (CRC) is the third most diagnosed cancer and the second leading cause of cancer-related mortality in the United States. Across the globe, people in the age group older than 50 are at a higher risk of CRC. Genetic and environmental risk factors play a significant role in the development of CRC. If detected early, CRC is preventable and treatable. Currently, available screening methods and therapies for CRC treatment reduce the incidence rate among the population, but the micrometastasis of cancer may lead to recurrence. Therefore, the challenge is to develop an alternative therapy to overcome this complication. Nanotechnology plays a vital role in cancer treatment and offers targeted chemotherapies directly and selectively to cancer cells, with enhanced therapeutic efficacy. Additionally, nanotechnology elevates the chances of patient survival in comparison to traditional chemotherapies. The potential of nanoparticles includes that they may be used simultaneously for diagnosis and treatment. These exciting properties of nanoparticles have enticed researchers worldwide to unveil their use in early CRC detection and as effective treatment. This review discusses contemporary methods of CRC screening and therapies for CRC treatment, while the primary focus is on the theranostic approach of nanotechnology in CRC treatment and its prospects. In addition, this review aims to provide knowledge on the advancement of nanotechnology in CRC and as a starting point for researchers to think about new therapeutic approaches using nanotechnology.     

Internalization of titanium dioxide nanoparticles by glial cells is given at short times and is mainly mediated by actin reorganization-dependent endocytosis

Many nanoparticles (NPs) have toxic effects on multiple cell lines. This toxicity is assumed to be related to their accumulation within cells. However, the process of internalization of NPs has not yet been fully characterized. In this study, the cellular uptake, accumulation, and localization of titanium dioxide nanoparticles (TiO₂ NPs) in rat (C6) and human (U373) glial cells were analyzed using time-lapse microscopy (TLM) and transmission electron microscopy (TEM). Cytochalasin D (Cyt-D) was used to evaluate whether the internalization process depends of actin reorganization. To determine whether the NP uptake is mediated by phagocytosis or macropinocytosis, nitroblue tetrazolium (NBT) reduction was measured and the 5-(N-ethyl-N-isopropyl)-amiloride was used. Expression of proteins involved with endocytosis and exocytosis such as caveolin-1 (Cav-1) and cysteine string proteins (CSPs) was also determined using flow cytometry.TiO₂ NPs were taken up by both cell types, were bound to cellular membranes and were internalized at very short times after exposure (C6, 30 min; U373, 2 h). During the uptake process, the formation of pseudopodia and intracellular vesicles was observed, indicating that this process was mediated by endocytosis. No specific localization of TiO₂ NPs into particular organelles was found: in contrast, they were primarily localized into large vesicles in the cytoplasm. Internalization of TiO₂ NPs was strongly inhibited by Cyt-D in both cells and by amiloride in U373 cells; besides, the observed endocytosis was not associated with NBT reduction in either cell type, indicating that macropinocytosis is the main process of internalization in U373 cells. In addition, increases in the expression of Cav-1 protein and CSPs were observed.In conclusion, glial cells are able to internalize TiO₂ NPs by a constitutive endocytic mechanism which may be associated with their strong cytotoxic effect in these cells; therefore, TiO₂ NPs internalization and their accumulation in brain cells could be dangerous to human health.     

A highly tumor-targeted nanoparticle of podophyllotoxin penetrated tumor core and regressed multidrug resistant tumors

Podophyllotoxin (PPT) exhibited significant activity against P-glycoprotein mediated multidrug resistant (MDR) tumor cell lines; however, due to its poor solubility and high toxicity, PPT cannot be dosed systemically, preventing its clinical use for MDR cancer. We developed a nanoparticle dosage form of PPT by covalently conjugating PPT and polyethylene glycol (PEG) with acetylated carboxymethyl cellulose (CMC-Ac) using one-pot esterification chemistry. The polymer conjugates self-assembled into nanoparticles (NPs) of variable sizes (20–120 nm) depending on the PPT-to-PEG molar ratio (2–20). The conjugate with a low PPT/PEG molar ratio of 2 yielded NPs with a mean diameter of 20 nm and released PPT at ∼5%/day in serum, while conjugates with increased PPT/PEG ratios (5 and 20) produced bigger particles (30 nm and 120 nm respectively) that displayed slower drug release (∼2.5%/day and ∼1%/day respectively). The 20 nm particles exhibited 2- to 5-fold enhanced cell killing potency and 5- to 20-fold increased tumor delivery compared to the larger NPs. The biodistribution of the 20 nm PPT-NPs was highly selective to the tumor with 8-fold higher accumulation than all other examined tissues, while the larger PPT-NPs (30 and 120 nm) exhibited increased liver uptake. Within the tumor, >90% of the 20 nm PPT-NPs penetrated to the hypovascular core, while the larger particles were largely restricted in the hypervascular periphery. The 20 nm PPT-NPs displayed significantly improved efficacy against MDR tumors in mice compared to the larger PPT-NPs, native PPT and the standard taxane chemotherapies, with minimal toxicity.     

常见抗生素与新型抗菌药物在临床上的研究应用进展

摘要：抗生素的研发与使用有效杀灭和抑制了众多病原菌，挽救了无数人的生命，但由于抗生素的不合理使用，导致细菌耐 药不断出现，耐药菌的感染已严重地威胁人类的生命健康。为此，本文主要对近年来临床上常用的抗生素如β-内酰胺类、喹诺酮 类、氨基糖苷类药物以及新型抗菌药物如抗菌肽和纳米颗粒的应用研究进行总结分析与探讨，为临床上治疗疾病提供一些参考。     

纳米颗粒和外泌体靶向载药系统诊治动脉粥样硬化的机遇与挑战

动脉粥样硬化是一种慢性炎症性疾病,粥样斑块慢性聚集并沉积于大中型动脉内膜,导致严重的狭窄和血运障碍,引发组织器官缺血缺氧。纳米药物相对于传统药物在动脉粥样硬化治疗中因其具有独特的优势而广泛受到关注。本文重点综述几种纳米靶向颗粒（系统）和外泌体靶向载药系统在抗动脉粥样硬化研究中的应用,简述代表性纳米材料的合成过程,对其靶向性进行分析,并概述纳米药物的益处和内在挑战。尽管面临着一些需要解决和完善的挑战,但是纳米颗粒和外泌体靶向载药治疗的前景广阔,并有望将其推广应用于临床实践中。     

纳米粒子应用于电化学癌症早期检测技术的研究进展

利用纳米电化学传感技术进行癌症的早期检测是将来生物医学领域的一个重要发展方向.简要介绍了肿瘤早期检测用标志物的概念和电化学检测这些标志物的原理,对纳米粒子应用于电化学癌症早期检测技术的研究进展进行了详细的评述,最后对该领域的应用前景进行了展望.     

磁性阿霉素白蛋白纳米粒的研制

目的：制作具有稳定磁性、能够携带化疗药物的白蛋白纳米粒,并对白蛋白纳米粒的磁性,药物含量进行检测。方法：将市售用Fe3O4粉末,经化学方法处理,制成纳米大小的Fe3O4泥糊,将Fe3O4泥糊、纯盐酸阿霉素、人体血清白蛋白按一定比例混合,通过在棉仔油中超声乳化,加热变性、乙醚洗涤等工艺制作出磁性阿霉素白蛋白纳米粒,用乙醇提取法提取磁性纳米粒中的阿霉素,并用荧光光度计测定含量。将纳米粒溶于生理盐水中,在光学显微镜下观察在磁场作用下磁性纳米粒的运动情况,通过检测溶液中的游离药物,观察在不同的加热温度下,磁性纳米粒的稳定性,并用电子显微镜观察纳米粒的内部结构。结果：磁性白蛋白纳米粒阿霉素含量为57．5μg/g,阿霉素包含率为98．3％,磁性白蛋白纳米溶液在光学显微镜下观察,在磁场的作用下,纳米粒迅速向磁铁的方向移动并发生聚集,当磁铁与纳米粒的距离加大时,纳米粒运动速度减慢,并沿磁力线的方向形成串珠状聚集。电子显微镜下观察,Fe3O4颗粒均匀分布在白蛋白纳米粒中,结论：磁性白蛋白纳米粒具有磁性稳定、靶向性强、药物包含率高、释药速率可控制的特点,为靶向药物治疗提供了可靠的载药工具。     

产时保健对母婴健康的影响

目的：了解产妇及胎儿在医院分娩过程中产时保健情况对母婴健康的影响。方法：对１１６６４例产妇接产情况,采用χ＾２检验对不同年份不同分娩方式及母婴分娩并发症发生率进行对比分析。结果：剖宫产率为４１．８４％,围产儿死亡率为１０．６８‰,产妇分娩并发症的发生率为５．９９％,其中产后出血占９５．４２％,剖宫产与阴式分娩产后出血率差异无显著性（χ＾２＝０．６６,Ｐ＞０．０５）,新生儿并发症发生率为８．５８％,     

Magnetic Iron Oxide Nanoparticles Mediated Gene Therapy for Breast Cancer-An In Vitro Study

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), also designated as Apo-2 ligand, is a typical member of the structurally related tumor necrosis factor (TNF) ligand family. It has been shown that TRAIL only induces the apoptosis of cancer cells rather than normal cells. This characteristic offers a new target for cancer treatment[1]. In fact, TRAIL gene has been successfully used for the treatment of cancer[2]. Viruses have been the common vectors used in TRAIL gene t…     

Magnetic Iron Oxide Nanoparticles Mediated Gene Therapy for Cancer An In Vitro Study

The aim of this study was to evaluate the feasibility and efficacy of using TRAIL gene to treat breast cancer mediated with a novel carrier - magnetic iron oxide nanoparticles (polyMAG-1000) coated with PEI. The magnetic iron oxide nanoparticles were used as gene carrier to transfect TRAIL gene into MCF-7 cells. The polyMAG-1000 without TRAIL gene was transfected into the tumor cells as negative control. TRAIL gene transfection with liposome as carrier served as positive control. The apoptosis of cells was detected with TUNEL method. The apoptosis ratio of tumor cells was measured with flow cytometry (FCM). It was found that the apoptosis occurred in the tumor cells after transfection of TRAIL gene mediated by both polyMAG-1000 and liposome. The apoptosis ratio in the group with polyMAG-1000 as gene carrier was (25.11±2.85) %, whereas it was (5.06±1.05) % in the control group with polyMAG-1000 (P＜0.01). The apoptosis ratio was as low as (18.31±2.44) % in the group with liposome as gene carrier (P＜0.05, as compared with the group with polyMAG-1000 as gene carrier). It is suggested that TRAIL gene may induce apoptosis in MCF-7 breast cancer cells. The magnetic iron oxide nanoparticles coated with PEI may be a potential gene carrier with high transfection efficacy for cancer gene therapy.