羟基磷灰石纳米粒子对肝癌H22小鼠肿瘤细胞凋亡的研究

目的通过不同浓度的羟基磷灰石(HAP)纳米粒子作用于肝癌H22小鼠肿瘤细胞,研究其对肿瘤细胞凋亡的影响。方法100只肝癌H22小鼠随即分组并连续服用不同剂量的HAP纳米粒子,11d后处死小鼠,计算抑瘤率和细胞凋亡率,评价不同剂量的HAP纳米粒子与H22小鼠肿瘤细胞生长的关系。结果肝癌H22小鼠肿瘤细胞对纳米羟基磷灰石(HAP)较敏感,能明显延长小鼠生存期,高剂量组与丝裂霉素结果相近(P>0.05)。实验后小鼠体重没有明显下降,抑瘤率和细胞的凋亡率随浓度升高而增大,呈明显的剂量依赖性(P<0.01)。结论不同浓度的羟基磷灰石(HAP)纳米粒子能够抑制H22肿瘤细胞的增殖,诱导肿瘤细胞的凋亡,并呈剂量依赖性。     

纳米铁粉对小鼠血糖和血脂的影响

[目的]探讨纳米铁粉对小鼠血糖、血脂的影响。[方法]分别以5g/kg剂量微米粒径铁粉(Micro-Fe)或纳米粒径铁粉(Nano-Fe)给小鼠1次经口灌胃,14d后处死;测定肝、肾脏器系数、血糖(Glu)、总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)的变化。[结果]Micro-Fe和Nano-Fe染毒小鼠肝脏系数明显高于对照组相(P﹤0.05)。与对照组相比,Nano-Fe染毒小鼠血清Glu明显降低(P﹤0.05);Micro-Fe组血清TG比control组有明显升高(P﹤0.05),Nano-Fe组血清TG比control组有升高趋势,但差异无统计学意义(P﹥0.05)。Control、Micro-Fe和Nano-Fe染毒组3组小鼠血清TC、LDL-C和HDL-C水平间差异无统计学意义(P﹥0.05)。[结论]大剂量Nano-Fe经口染毒可使血清Glu降低,对TC、TG、HDL-C和LDL-C无明显影响。     

纳米氧化镁对小鼠血清生化指标的影响

目的探讨纳米镁材料对小鼠血清生化指标的影响。方法按照固定剂量(5g/kg)法以镁粉、微米氧化镁和纳米氧化镁一次经口灌胃。14d后处死动物取血清观察常规生化指标的变化。结果纳米氧化镁组小鼠血清LDH和ALP明显低于微米氧化镁组(P<0.05),但与对照组相比无明显变化(P>0.05)。结论纳米氧化镁对血清LDH和ALP的影响与微米氧化镁材料有明显差别,其生化毒性作用可能与微米氧化镁材料有所不同。     

阿霉素磁性壳聚糖微球的制备及释放实验

应用改进的悬浮交联技术制备磁性壳聚糖(chitosan,CS)纳米微球。结果显示:该药物微球基本呈球形,其粒径在200~800 nm之间,并且显示了好的磁响应性。阿霉素(doxorubicin,DOX)为试验药物,DOX和CS以化学键(-N=C-)结合在一起,药物含量在1%~15%(w/w)。pH值的大小对其药物体外释放试验的影响很大,当pH为1、2和4时,7 d内药物的释放从22.0%、13.4%降至4.1%。该微球为pH敏感的磁靶向药物微球。     

纳米钙磷结晶种植体表面理化性能分析

目的探讨两种纳米钙磷结晶种植体表面理化性能的差异。方法通过扫描电镜（SEM）观察两种种植体纳米晶体涂层表面形貌，能谱分析（EDS）、X射线光电子能谱仪（XPS）和X射线衍射（XRD）分析涂层晶体的化学组分及晶相，原子力显微镜（AFM）检测表面粗糙度。测量超纯水、二碘甲烷、甘油和甲酰胺在样品表面的接触角并计算表面能。结果Bicon NanoTite^TM种植体表面可见直径20～200nm、圆形或椭圆形晶体随机分布并与表面融为一体：直径20-100nm粒状晶体散在分布于3I NanoTite^TM种植体表面，在凹陷周围密集累积成白色山峰状，凹陷底部晶体数量较少。钛基体外露。XPS证实Bicon NanoTite^TM种植体表面的纳米晶体化学组分为Ca10（PO1）6（OH）2和CaCO3，3I NanoTite^TM种植体表面晶体化学组分是Ca8H2（PO4）6·5H2O。XRD显示两种种植体表面涂层晶体均为无定形结晶。Bicon NanoTite^TM和3I NanoTite^TM的表面粗糙度中，轮廓算术平均偏差（Ra）分别为（0．43±0．10）μm和（0．15±0．05）μm，微观不平度和点高度（Rz）分别为（2．13±0．7）μm和（0．64±0．03）μm，Bicon NanoTite^TM的Ra和Rz均较3I NanoTite^TM的高（P〈0．05）。Bicon NanoTite^TM和3I NanoTite^TM的分散成分分别为24．49、24．10mN·m^-1．极性成分分别为17．82、11．04mN·m^-1，总表面能分别为42．30、35．15mN·m^-1。结论Bicon NanoTite^TM种植体表面纳米晶体的中含有Ca10（PO4）6（OH）2，在化学成份上较3I NanoTite^TM的纳米晶体更接近羟磷灰石，物理化学性能较好。     

Colorectal cancer cell detection by 5-aminolaevulinic acid-loaded chitosan nano-particles

Colorectal cancer is one of the leading causes of malignant death in Taiwan because it often remains undetected until later stages of the disease. In this study, we designed an oral form nano-particle to encapsulate 5-aminolaevulinic acid (5-ALA) to improve the detection of colorectal cancer cells in vivo. The nano-particle should escape from bacteria uptake in the gastrointestinal tract which seriously interferes the results of endoscopic observation. In this study, chitosan was mixed with sodium tripolyphosphate (STPP) and 5-ALA to prepare chitosan nano-particles (CN) and 5-ALA loaded chitosan nano-particles (CNA) by adding different pH values and concentrations of 5-ALA solution. The average particle size and zeta-potential of CN and CNA were measured by the Zetasizer-3000. The results revealed that particle size with different zeta-potential could be manipulated just by 5-ALA concentrations and pH values. CNA particles prepared at pH 7.4 and pH 9 of 5-ALA solutions with a concentration higher than 0.5 mg/ml showed a promising loading efficiency of up to 75% and an optimum average particle size of 100 nm. The zeta-potential for CNA was over 30 mV that kept the nano-particle stable without aggregation when stored in suspension solution. Fluorescence microscope examination showed that CNA could be engulfed by Caco-2 colon cancer cells but showed no evidence of being taken up by Escherichia coli. This result implies that CNA could exclude the influence of normal flora inside the gut and serves as an adequate tool for fluorescent endoscopic detection of colorectal cancer cells in vivo.     

Numerical investigation of septal deviation effect on deposition of nano/microparticles in human nasal passage

Three dimensional computational models of both sides of human nasal passages were developed to investigate the effect of septal deviation on the flow patterns and deposition of micro/nano-particles in the realistic human nasal airways before and after septoplasty. A series of coronal CT scan images from a live 25-year old nonsmoking male with septal deviation in his right nasal passage was used to construct the model. For low to moderate activities, the steady airflows through the nasal passages were simulated. Eulerian and Lagrangian approaches were used, respectively, for nano- and micro-particles. The results show that the flow field and particle deposition strongly depend on the passage geometry especially for micro particles. In particular, the deposition rate in the passage with septal deviation was much higher compared with those in the normal (left) passage and the postoperative passage. Despite the similarity of total micro-particle deposition in the postoperative and the normal cavities, the regional deposition patterns were quite different in these passages. The deposition of nano-particles, however, showed similar trends in the postoperative right nasal passage and the normal left passage. The simulation results showed that in addition to the major alteration of the airflow pattern after the septoplasty operation, there are significant changes in the deposition pattern of nano- and micro-particles. Despite the anatomical differences between the available experimental configuration and the present computer model, the simulation results for the deposition efficiency of particles of different sizes are in qualitative agreement with the available data.     

59 Fe示踪谷氨酸包被三氧化二铁纳米颗粒的制备及其在小鼠体内的生物学分布

摘要：目的：应用^59Fe对谷氨酸包被三氧化二铁纳米颗粒(nano-Fe2O3-Glu)进行示踪标记，研究其在小鼠体内的生物学分布。方法：采用^59Fe标记谷氨酸修饰共沉淀法制备nano-^59Fe-Fe2O3-Glu，经肝间质或尾静脉注入小鼠体内，测定给药后不同时间nano-^59Fe—Fe2O3-Glu在血液、心、肝、脾、双肾、肺、脑、眼、性腺等主要组织器官中的放射性，观察其在动物体内的药代动力学特征，包括吸收、分布、消除的特点，组织蓄积及可能作用的靶器官。结果：nano-^59Fe-Fe2O3-Glu粒径15nm，^59Fe标记的nano—Fe2O3-Glu经尾静脉注射，分别于1h和2天肝和脾达到高峰，峰值分别为48．9％ID／g和22．9％ID／g；肝间质注射后肝8天、脾24h达到高峰，在高、中、低三个剂量组肝脏分别为41．3％ID／g、20．8％ID／g和14．6％ID／g，脾分别为23．6％ID／g、21．2％ID／g和12．5％ID／g。脑、眼、性腺亦含有一定的放射性，表明纳米颗粒Fe2O3可通过血-脑、血-睾等屏障。经尾静脉和肝间质注射药物后，血液的放射性均在16天达高峰，然后逐渐下降，48天仍含有一定的放射性。结论：^59Fe示踪nano-^59Fe-Fe2O3-Glu体内生物学分布灵敏、准确，其在体内主要的靶器官是肝和脾，无血液毒性与细胞毒性。     

Therapeutic polymers for dental adhesives: Loading resins with bio-active components

Objectives

Many recent adhesives on the market exhibit reasonable clinical performance. Future innovations in adhesive materials should therefore seek out novel properties rather than simply modifying existing technologies. It is proposed that adhesive materials that are “bio-active” could contribute to better prognosis of restorative treatments.

Methods

This review examines the recent approaches used to achieve therapeutic polymers for dental adhesives by incorporating bio-active components. A strategy to maintain adhesive restorations is the focus of this paper.

Results

Major trials on therapeutic dental adhesives have looked at adding antibacterial activities or remineralization effects. Applications of antibacterial resin monomers based on quaternary ammonium compounds have received much research attention, and the loading of nano-sized bioactive particles or multiple ion-releasing glass fillers have been perceived as advantageous since they are not expected to influence the mechanical properties of the carrier polymer.

Significance

The therapeutic polymer approaches described here have the potential to provide clinical benefits. However, not many technological applications in this category have been successfully commercialized. Clinical evidence as well as further advancement of these technologies can be a driving force to make these new types of materials clinically available.