聚乙二醇-聚(乳酸-碳酸酯)-紫杉醇纳米胶束对SKOV3卵巢癌的抑制作用

制备了2种两亲性生物降解嵌段共聚物聚乙二醇-聚(乳酸-碳酸酯),进而与紫杉醇和叶酸共价键合,形成高分子-紫杉醇键合物和高分子-叶酸键合物,将它们共组装成复合纳米胶束,直径约50 nm,含紫杉醇27 wt%,含叶酸1.4 wt%.培养了人卵巢癌SKOV3细胞,采用四氮唑(MTT)比色法、流式细胞术(FCM)证明了市售紫杉醇(Taxol)、紫杉醇胶束(M(PTX))及叶酸靶向紫杉醇胶束(FA-M(PTX))在10μg/mL浓度下对SKOV3细胞生长有明显抑制作用,并且M(PTX)和FA-M(PTX)优于Taxol.构建了皮下卵巢癌balb/c荷瘤裸鼠动物模型,考察了Taxol,M(PTX)和FA-M(PTX)对肿瘤生长的抑制能力.在20 mg/kg的剂量下,体外测量的肿瘤体积、9天观察的瘤体重量以及动物的生存期数据都表明,Taxol,M(PTX)和FA-M(PTX)三者都能抑制SKOV3肿瘤的生长,抑制能力的顺序为Taxol相似文献   

两亲性双硫键双菁染料的合成及谷胱甘肽响应荧光性质研究

菁染料具有优秀的光学性质,常用于肿瘤组织的实时可视化荧光成像。但普通菁染料成像背景较高,对肿瘤组织的靶向能力差。将菁染料自组装成纳米粒子可使染料形成聚集并实现荧光淬灭（聚集淬灭效应）,降低其在普通组织的成像背景;同时,纳米粒子的高渗透长滞留效应（EPR效应）可提高染料对肿瘤组织的靶向能力。本文设计合成了一种双硫键双菁染料（SO₃Cy7-ss-Cy7.5）,该染料由于两亲性的特性易在水溶液中自组装成纳米粒子,荧光淬灭高达92%;当纳米粒子与谷胱甘肽（GSH）响应后,淬灭的荧光逐渐恢复,最终实现16倍的荧光强度增强。因此,该双菁染料具有良好的肿瘤组织高分辨成像潜力。      

叶酸受体介导的肿瘤靶向光学成像技术

叶酸受体(FR)在肿瘤细胞中都有过度表达,而在正常组织中保守表达,利用叶酸受体与叶酸及其类似物高亲合力结合的特性,将叶酸偶联荧光探针输送到肿瘤组织,从而实现肿瘤组织的特异性靶向光学成像。本文阐述了叶酸荧光探针的结构及其用于标记肿瘤细胞的作用机制,介绍了近十年来叶酸受体介导的肿瘤靶向光学成像技术,例如有机荧光染料,染料掺杂纳米颗粒,量子点,磁性纳米微粒以及多功能纳米粒子等在肿瘤靶向成像中的研究及应用进展,指出了当前研究中的主要发展方向和仍需解决的问题。     

键合紫杉醇纳米胶束对H22肝癌小鼠的体内疗效评估

以H22肝癌的balb/c荷瘤小鼠为动物模型,考察了紫杉醇纳米胶束、紫杉醇注射液和生理盐水对小鼠肿瘤的抑制效果。 紫杉醇注射液组、紫杉醇纳米胶束低剂量组和紫杉醇纳米胶束高剂量组在给药后10 d的肿瘤相对体积抑制率分别为22%、49%和67%,瘤重抑制率分别为29%、45%和47%;蛋白表达检测结果显示,紫杉醇纳米胶束组呈现p53的高表达和bcl-2的低表达,说明紫杉醇纳米胶束对小鼠H22肝癌的抑制作用强于紫杉醇注射液。     

聚乳酸包载5-氟尿嘧啶靶向超微粒子对人胃癌转移瘤的靶向性和控制释放研究

使用w／o／w复乳法制备聚乳酸载5-氟尿嘧啶超微粒子,使用透射电镜、激光粒度仪和紫外分光光度计对超微粒子进行表征,并考察其体外释药性质。将^99mTc标记的连有VEGF121单克隆抗体的超微粒子通过尾静脉注射到SCID裸鼠体内,观察它对胃癌转移瘤的靶向效果和治疗效果。结果显示超微粒子成圆球形,平均粒径为195.2nm,多分散系数为0.148,靶向载药超微粒子的载药率为8．23％,包封率为24．71％。聚乳酸载5-Fu超微粒子在PBS缓冲溶液中具有较好的控释效果,累积释放量Q与时间平方根t^1/2基本呈线性关系．尾静脉注射靶向超微粒子两小时以后可看到大部分超微粒子集中到肿瘤部位。在所有的实验组中,含5-Fu靶向载药超微粒子组的疗效最好,说明本靶向载药超微粒子具有抑制肿瘤的血管生成并在肿瘤组织释放化疗药物抑制肿瘤生长的双重作用。     

111In-CCPM-RGD纳米粒子的合成及其双模态分子显像研究

本研究以具有优良生物学性能的近红外核交联聚合胶束纳米粒子（NIRF-CCPM）为载体,将具有肿瘤靶向性的多肽RGD（精氨酸-甘氨酸-天冬氨酸）与该纳米粒子偶联,并通过放射性核素¹¹¹In进行标记,放射性标记过程中,标记率96%,放化纯度大于99%. ¹¹¹In-CCPM-RGD分子探针表现出良好的放射标记/光学性质. 体外稳定性研究表明,25 ℃条件下其在5%小牛血清缓冲液中静置72 h,依然保持有90%的稳定性. 同时采用核医学/光学显像两种影像手段评价了该双模态分子探针在U87肿瘤模型裸鼠体内的代谢情况：在静脉注射11.1 MBq ¹¹¹In-CCPM-RGD纳米粒子24 h、72 h进行SPECT/CT的显像,其在肿瘤部位表现出特异性的浓集. 同时,其在NIRF的显像中表明相应肿瘤区域出现特异性富集. ¹¹¹In-CCPM-RGD纳米粒子的设计、合成及初步生物学评价说明其同时兼具光学和核医学显像功能,是性能优良的新型双模态纳米分子探针,能够帮助提高肿瘤的诊断效能,为建立光学/核医学用于肿瘤靶向双模式成像奠定理论基础.     

手术导航用荧光探针

荧光成像技术因具有操作简便、分辨率高、安全性好且可实时成像等优势,在术中导航中具有广阔的应用前景.虽然目前还没有靶向荧光探针在临床上得到批准,但已经有相当一部分荧光探针进入了临床试验阶段.最早进入临床试验的是一些偶联肿瘤靶向配体的荧光染料,例如近红外菁染料(IRDye800CW)标记的肿瘤特异抗体,叶酸标记的异硫氰酸荧...     

含叶酸功能端基Pluronic F127的合成及其在水中的形态

通过一系列反应将三嵌段共聚物Pluronic F127的端羟基转变为氨基。利用氨基化F127大单体,最终成功的将生物活性大分子叶酸接到了F127端基上(F127-Folate) 作为靶向配体。利用1H-NMR对嵌段共聚物的结构进行了表征。用透析法制备胶束溶液,利用TEM研究了F127-Folate在水溶液中的自组装形态,结果表明F127-Folate正在水溶液中自组装形成纳米胶束。     

FITC标记的叶酸类衍生物的合成及显像研究

本文的目的是研究荧光素FITC标记的叶酸衍生物的肿瘤靶向性。以对氨基苯乙酸为起始原料,合成了N-(2-氨基乙基)-2-(4-氨基苯基)乙酰胺。以DMAP、EDCI作缩合剂,将N-(2-氨基乙基)-2-(4-氨基苯基)乙酰胺偶联至叶酸的α位和γ位羧基,得到叶酸衍生物FA-EA,用荧光素FITC标记FA-EA得到FA-EA-(FITC)2。反应中间体及最终产物用HPLC、1H NMR和MS表征。通过尾静脉注射FA-EA-(FITC)2,观察其在荷瘤裸鼠主要脏器和肿瘤的分布及对荷瘤裸鼠进行活体荧光显像研究。实验结果表明,FA-EA-(FITC)2在肿瘤部位有明显的聚集,在其他主要脏器几乎看不到其分布,说明FA-EA-(FITC)2具有较好的肿瘤靶向性。本研究为进一步研制可用于肿瘤显像的叶酸类显像药物提供了依据。     

叶酸修饰星型端氨基PEG-PLGA纳米胶束的制备及肿瘤细胞靶向作用

合成了星型多臂端氨基聚乙二醇(PEG)/聚乳酸-羟基乙酸(PLGA)两亲性嵌段共聚物(4s-PLGA-PEG-NH₂), 并通过核磁共振和凝胶渗滤色谱法对其结构进行表征; 采用溶剂挥发法制备阿霉素载药纳米胶束, 利用EDC缩合法与叶酸偶联, 得到叶酸修饰的星型端氨基PEG-PLGA纳米胶束; 采用动态光散射、 紫外光谱及透射电镜等手段对纳米胶束进行了表征; 对载药纳米胶束在HeLa细胞中的摄取及细胞毒性进行了初步评价. 结果表明, 经叶酸修饰的星型多臂端氨基PEG-PLGA载药纳米胶束可有效提高HeLa细胞的摄取率以及对HeLa细胞的杀伤率, 表明其可作为一类新型的靶向抗肿瘤药物递送载体.     

两亲性嵌段共聚物mPEG-b-PCL/FA的合成及其药物释放性能

以苯甲醇为引发剂,在辛酸亚锡催化下引发ε-环己内酯(ε-CL )开环聚合,合成了聚己内酯(PCL).分别利用端甲氧基聚乙二醇(mPEG)、PCL及叶酸(FA)与三氯三嚎中不同的氯反应,得到两亲性嵌段共聚物mPEG-b-PCL/FA;采用傅立叶变换红外光谱仪和核磁共振谱仪等表征了mPEG-b-PCL/FA的组成和结构;采...     

嵌段共聚物聚(异丙基丙烯酰胺)-b-聚(双丙酮丙烯酰胺)制备及其对叶酸的载负和释放

以N-异丙基丙烯酰胺(NIPAm)和双丙酮丙烯酰胺(DAAM)为原料,采用可逆加成 断裂链转移(RAFT)可控聚合反应法合成了两亲性两嵌段共聚物 聚(异丙基丙烯酰胺)-b-聚(双丙酮丙烯酰胺)(PNIPAm-b-PDAAM),用红外光谱(FT-IR)、核磁共振(1H NMR)和凝胶渗透色谱(GPC)对其结构和组成进行了表征。 这种共聚物在水溶液中能够自组装成稳定的聚合物胶束,通过荧光探针测得其低临界胶束浓度(CMC)约为7.0 mg/L。 采用扫描电子显微镜(SEM)和动态激光光散射(DLS)测得,PNIPAm-b-PDAAM在水溶液中自组装成核壳结构的球形胶束,SEM测得其直径约150 nm,且分散性良好。 以其聚合物胶束为载体、叶酸(FA)为模型药物,模拟人体生理环境进行药物体外释放。 结果表明,叶酸的负载量及负载率分别为25%和74%。 在人体温度37℃、pH值分别为4.0、6.86、9.18磷酸缓冲溶液(PBS)中,FA在20 h内的释放均比25 ℃快,释放速率随pH值增加而增大,最大累积释放率分别为31%、67%和72%。     

Synthesis of multifunctional Ag@Au@phenol formaldehyde resin particles loaded with folic acids for photothermal therapy

Multifunctional Ag@Au@ phenol formaldehyde resin (PFR) particles loaded with folic acids (FA) have been designed for killing tumor cells through photothermy conversion under the irradiation of near-infrared (NIR) light. Possessing the virtue of good fluorescence, low toxicity, and good targeting, the nanocomposite consists of an Ag core, an Au layer, a PFR shell, and folic acids on the PFR shell. The Ag@PFR core-shell structure can be prepared with a simple hydrothermal method after preheating. We then filled the PFR shell with a layer of Au by heating and modified the shell with polyelectrolyte to change its surface charge state. To capture tumor cells actively, FA molecules were attached onto the surface of the Ag@Au@PFR particles in the presence of 1-ethyl-3-(3-dimethly aminopropyl) carbodiimide (EDAC) and N-hydroxysuccinimide (NHS). Owing to the excellent property of Au NPs and Ag NPs as photothermal conversion agents, the Ag@Au@ PFR@FA particles can be utilized to kill tumor cells when exposed to NIR light.     

Folate‐Conjugated and Dual Stimuli‐Responsive Mixed Micelles Loading Indocyanine Green for Photothermal and Photodynamic Therapy

A folic acid targeted mixed micelle system based on co‐assembly of poly(ε‐caprolactone)‐b‐poly(methoxytri(ethylene glycol) methacrylate‐co‐N‐(2‐methacrylamido)ethyl folatic amide) and poly(ε‐caprolactone)‐b‐poly(diethylene glycol monomethyl ether methacrylate) is developed to encapsulate indocyanine green (ICG) for photothermal therapy and photodynamic therapy. In this study, the use of folic acid is not only for specific cancer cell recognition, but also in virtue of the carboxylic acid on folic acid to regulate the pH‐dependent thermal phase transition of polymeric micelles for controlled drug release. The prepared ICG‐loaded mixed micelles possess several superior properties such as a preferable thermoresponsive behavior, excellent storage stability, and good local hyperthermia and reactive oxygen species generation under near‐infrared (NIR) irradiation. The photototoxicity induced by the ICG‐loaded micelles has efficiently suppressed the growth of HeLa cells (folate receptor positive cells) under NIR irradiation compared to that of HT‐29, which has low folate receptor expression. Hence, this new type of mixed micelles with excellent features could be a promising delivery system for controlled drug release, effective cancer cell targeting, and photoactivated therapy.     

光谱法研究叶酸与牛血清白蛋白在含铁(Ⅲ)环境中的相互作用

采用荧光光谱法及紫外光谱法研究了叶酸(FA)与生物大分子牛血清白蛋白(BSA)在含Fe3+环境中的相互作用.结果表明,叶酸及Fe3+均导致BSA的内源荧光猝灭,猝灭机制均为静态猝灭;无Fe3+离子时,叶酸与BSA间的作用力主要是静电力;当存在Fe3+离子时,叶酸与BSA间的作用力主要是氢键和范德华力,此时Fe3+以"离子架桥"的方式参与叶酸和BSA的结合过程.     

Studies on core–shell structural nano-micelles based on star block copolymer of poly(lactide) and poly(2-(dimethylamino)ethyl methacrylate)

Inorganic/polymer hybrid star-shaped block copolymer nano-micelles were synthesized. In the synthetic route, multi-hydroxyl polyhedral oligomeric silsequioxane(POSS-(OH)₃₂) was employed as the starting molecule to initiate ring-opening polymerization of d,l-lactide. 2-(Dimethylamino)ethyl methacrylate was found to polymerize at the end of polylactic acid chains, following mechanism of atom transfer radical polymerization. The well-defined star block copolymer core–shell nano-micelles were finally obtained. The structures of the copolymer and the micelles were characterized extensively. The micelles exhibited a regular spherical shape with an average diameter of 170 nm which was confirmed by transmission electron microscopy and dynamic laser scattering. The sizes of both the core and the shell were controlled by adjusting the feed ratios during the syntheses. The micelles demonstrated pH- and temperature-sensitive behaviors.     

Biodistribution and Pharmacokinetic Studies of a Porphyrin Dimer Photosensitizer (Oxdime) by Fluorescence Imaging and Spectroscopy in Mice Bearing Xenograft Tumors

Herein, we present a study of the pharmacokinetics and biodistribution of a butadiyne‐linked conjugated porphyrin dimer (Oxdime) designed to have high near‐infrared (NIR) 2‐photon absorption cross‐section for photodynamic therapy (PDT). Changes in biodistribution over time were monitored in mice carrying B16‐F10 melanoma xenografts, following intravenous injection. Using fluorescence imaging of live animals and analyzing isolated organs ex vivo at different time points between 30 min and 24 h after injection, accumulation of Oxdime was measured in several organs (heart, kidney and liver) and in tumor. The concentration in the plasma was about 5–10 times higher than in other tissues. The fluorescence signal peaked at 3–12 h after injection in most tissues, including the tumor and the plasma. The change in the fluorescence emission spectrum of the sensitizer over time was also monitored and a shift in the maximum from 800 to 740 nm was observed over 24 h, showing that the Oxdime is metabolized. Significant quantities accumulated in the tumor, indicating that this PDT sensitizer may be promising for cancer treatment.     

Folic Acid Modified Polymeric Micelles for Intravesical Instilled Chemotherapy

In this study,a targeting micellar drug delivery system was developed for intravesical instilled chemotherapy of bladder cancer.The amphiphilic diblock copolymer poly(ε-caprolactone)-block-poly(ethylene glycol) (PCL-b-PEO) with functional amino group (NH2) at the end of PEO block was synthesized.Then the copolymer was conjugated with folic acid (FA) and fluorescein isothiocyannate (FITC) via the PEO-NH2 terminus,and then assembled into micelles with the target moiety and fluorescence labeling.In addition,drug loaded micelles were also fabricated with anticancer drug doxorubicin (DOX) encapsulated in the hydrophobic core.The micelles were characterized in terms of size,drug loaded efficiency and critical micellization concentration (CMC) by means ofDLS,UV and fluorescence spectra.In vitro cellular uptake and cytotoxicity studies showed that FA modified PCL-b-PEO-FA micelles have a greater targeting efficiency to human bladder cancer cell (T-24 cell) compared to PCL-b-PEO-NH2 micelles due to the conjugation of FA on the surface,while no targeting effect to normal tissue originated human embryonic kidney 293 (HEK-293) cells was observed,enabling the micelles a promising drug carrier for intravesical instilled chemotherapy of bladder cancer.     

Biocompatible organic dots with aggregation-induced emission for in vitro and in vivo fluorescence imaging

Fluorescent probes play a key role in modern biomedical research. As compared to inorganic quantum dots (QDs) composed with heavy metal elements, organic dye-based fluorescent nanoparticles have higher biocompatibility and are richer in variety. However, traditional organic fluorophores tend to quench fluorescence upon aggregation, which is known as aggregation-caused quenching (ACQ) effect that hinders the fabrication of highly emissive fluorescent nanoparticles. In this work, we demonstrate the synthesis of organic fluorescent dots with aggregation-induced emission (AIE) in far-red/near-infrared (FA/NIR) region. A conventional ACQ-characteristic fluorescent dye, 3,4:9,10-tetracarboxylic perylene bisimide (PBI), is converted into an AIE fluorogen through attaching two tetraphenylethylene (TPE) moieties. The fluorescent dots with surface folic acid groups are fabricated from PBI derivative (DTPEPBI), showing specific targeting effect to folate receptor-overexpressed cancer cells. In vivo studies also suggest that the folic acid-functionalized AIE dots preferentially accumulate in the tumor site through enhanced permeability and retention (EPR) effect and folate receptor-mediated active targeting effect. The low cyto-toxicity, good FR/NIR contrast and excellent targeting ability in in vitro/in vivo imaging indicate that the AIE dots have great potentials in advanced bioimaging applications.