Bcl-2和Bag-1在肝外胆管癌中的表达及意义

目的:研究B细胞淋巴瘤-2(B-cell leukemia-2,Bcl-2)和Bcl-2结合抗凋亡基因-1(Bcl-2associated athanogene-l,Bag-1)在肝外胆管癌组织中的表达情况,探讨其表达强度与胆管癌临床病理特征的关系.方法:采用免疫组化法检测50例肝外胆管癌组织及30例胆囊管组织中Bcl-2和Bag-1蛋白的表达情况,结合临床病理特征进行统计学分析.结果:Bcl-2和Bag-1蛋白在胆管癌组织中的表达阳性率(88.0％、70.0％)均高于胆囊管组织(43.3％、50.0％)(P＜0.05),差异有统计学意义.Bcl-2和Bag-1的表达程度与胆管癌的分化程度、临床分期及有无淋巴结转移有关,Bcl-2和Bag-1的表达呈一致性.结论:Bcl-2和Bag-1与胆管癌的发生发展有密切关系,Bag-1可能协同Bcl-2参与胆管癌的发生、发展,两者的表达程度密切相关,可作为胆管癌患者预后的预测因素.     

Stem-Cell-Based Gene Therapy for HIV Infection

Despite the enormous success of combined anti-retroviral therapy, HIV infection is still a lifelong disease and continues to spread rapidly worldwide. There is a pressing need to develop a treatment that will cure HIV infection. Recent progress in stem cell manipulation and advancements in humanized mouse models have allowed rapid developments of gene therapy for HIV treatment. In this review, we will discuss two aspects of HIV gene therapy using human hematopoietic stem cells. The first is to generate immune systems resistant to HIV infection while the second strategy involves enhancing anti-HIV immunity to eliminate HIV infected cells.     

Characterization of immobilized tyrosinase – an enzyme that is stable in organic solvent at 100 °C

Tyrosinase is a copper-containing enzyme present in plant and animal tissues, which catalyzes the production of melanin and other pigments. In organic solvent, tyrosinase can convert N-acetyl-l-tyrosine ethyl ester (insoluble in aqueous) to a derivative of l-dopamine (a drug used for the treatment of Parkinson''s disease). Thus, the performances of tyrosinase in organic solvent have attracted scientific attention since 1980. In this work, we investigated the stability of immobilized tyrosinase at high temperature in anhydrous organic solvent. Triethylaminoethyl cellulose (TEAE-Cellulose) performed the best out of six immobilization platforms. The dry immobilized tyrosinase became extremely thermostable in organic solvent, and the half-life of the dry immobilized tyrosinase in organic solvent is strongly related to the polarity of the organic solvent than their log P value. The immobilized tyrosinase loses its activity instantaneously in aqueous solution at 100 °C, but it keeps enzymatic activity within 10 min in hydrophilic methanol and over one month in hydrophobic hexane (log P: 4.66, non-polar) even incubating at 100 °C. This research provides valuable information for the design of new biocatalysts.

Immobilized tyrosinase in hexane can withstand 100 °C over one week, and the half-life of the dry immobilized tyrosinase in organic solvent is strongly related to the polarity of the organic solvent.     

Binary and ternary complexes based on polycaprolactone-graft-poly (N, N-dimethylaminoethyl methacrylate) for targeted siRNA delivery

Small interfering RNA (siRNA) is a powerful gene silencing tool and has promising prospects in basic research and the development of therapeutic reagents. However, the lack of an effective and safe tool for siRNA delivery hampers its application. Here, we introduced binary and ternary complexes that effectively mediated siRNA-targeted gene silencing. Both complexes showed excellent siRNA loading even at the low N/P/C ratio of 3:1:0. FACS and confocal microscopy demonstrated that nearly all cells robustly internalized siRNAs into the cytoplasm, where RNA interference (RNAi) occurred. Luciferase assay and Western blot verified that silencing efficacy reached >80%, and introducing folate onto the ternary complexes further enhanced silencing efficacy by about 10% over those without folate at the same N/P/C ratio. In addition, the coating of PGA-g-mPEG decreased the zeta potential almost to electroneutrality, and the MTT assay showed decreased cytotoxicity. In vivo distribution measurement and histochemical analysis executed in C57BL/6 and Hela tumor-bearing BALB/c nude mice showed that complexes accumulated in the liver, lungs, pancreas and tumors and were released slowly for a long time after intravenous injection. Furthermore, ternary complexes showed higher siRNA fluorescence intensity than binary complexes at the same N/P ratio in tumor tissues, those with folate delivered more siRNAs to tumors than those without folate, and more folate induced more siRNA transport to tumors. In addition, in vivo functional study showed that both binary and ternary complexes mediated down-regulation of ApoB in liver efficiently and consequently blocked the secretion of fatty acids into the blood, resulted in lipid accumulation in liver, liver steatosis and hepatic dysfunction. In conclusion, these complexes provided a powerful means of administration for siRNA-mediated treatment of liver-related diseases and various cancers, especial for pancreatic and cervical cancer.     

Poly(ε‐caprolactone)‐graft‐poly(2‐(dimethylamino)ethyl methacrylate) Amphiphilic Copolymers Prepared via a Combination of ROP and ATRP: Synthesis,Characterization, and Self‐Assembly Behavior

Poly(ε‐caprolactone)‐graft‐poly(2‐(dimethylamino) ethyl methacrylate) (PCL‐g‐PDMAEMAs), a kind of amphiphilic graft copolymer, was prepared by combination of ROP and ATRP. The FTIR, ¹H NMR, and GPC results indicate that well‐defined polymers with controlled graft density and length of side chain were successfully synthesized. We prepared PCL‐g‐PDMAEMA nanoparticles by employing a nanoprecipitation technique. The pH‐ and thermosensitive properties of PCL‐g‐PDMAEMA nanoparticles were investigated by ¹H NMR, TEM, and DLS. It was found that the nanoparticles with an average size of 120 nm presented core–shell structure in aqueous dispersion. Furthermore, the nanoparticles are sensitive to temperature in base while not in an acidic environment.

     

Adjustable degradation and drug release of a thermosensitive hydrogel based on a pendant cyclic ether modified poly(ε-caprolactone) and poly(ethylene glycol)co-polymer

The convenient and precise fabrication of drug–hydrogel formulations with satisfactory degradability and a well-controlled drug release profile are crucial factors for injectable hydrogel formulations in clinical applications. Here a new injectable thermosensitive hydrogel formed from poly(ε-caprolactone) (PCL)–poly(ethylene glycol)–poly(ε-caprolactone) amphiphilicco-polymers with 1,4,8-trioxa[4.6]spiro-9-undecanone (TOSUO) moieties incorporated in the poly(ε-caprolactone) (PCL)block (PECT) was constructed to provide a route to tailor the degradation and drug release behavior. The effect of hydrophilic cyclic ether moieties on the degradation of and drug release by PECT hydrogels were evaluated in vitro and in vivo. The results indicated that a freeze-dried powder of paclitaxel-loaded PECT nanoparticles rapidly dissolved in water at ambient temperature with slightly shaking and formed a stable injectable in situ drug–hydrogel formulation at body temperature, which is convenient for clinical operations because it avoids the need for pre-quenching or long-term incubation. The paclitaxel distribution was also more quantitative and homogeneous on entrapping paclitaxel in PECT nanoparticles. Further, the small number of pendant cyclic ether groups in PCL could decrease the cystallinity and hydrophobicity and, as a result, the in vitro and in vivo retention time of PECT hydrogels and the release of entrapped paclitaxel could be tuned from a few weeks to months by varying the amount of PTOSUO in the hydrophobic block. Significantly, paclitaxel-loaded PECT nanoparticles and free paclitaxel could be simultaneously released during the in vitro paclitaxel release from PECT hydrogels. A histopathological evaluation indicated that in vivo injected PECT hydrogels produced only a modest inflammatory response. Thus pendant cyclic ether modification of PCL could be an effective way to achieve the desired degradation and drug release profiles of amphiphilicco-polymer thermosensitive hydrogels and PECT hydrogels may be suitable for local drug delivery.     

Investigation on injectable, thermally and physically gelable poly(ethylene glycol)/poly(octadecanedioic anhydride) amphiphilic triblock co-polymer nanoparticles

A family of injectable, biodegradable and thermosensitive co-polymer nanoparticle (NP) hydrogels based on mPEG-b-POA-b-mPEG, which was synthesized from mono-methoxy poly(ethylene glycol) (mPEG) and poly(octadecanedioic anhydride) (POA), was investigated in this paper. It was found that the aqueous dispersions of these NPs underwent a reversible gel-sol transition upon temperature change. By using paclitaxel and Bovine serum albumin (BSA) as model drugs, we noticed that the in vitro releases of both in situ gel-forming formulations were sustained and no initial burst releases were observed for 7 days. In vitro cytotoxicity tests via MTT assay indicate that mPEG-b-POA-b-mPEG NPs are non-toxic to normal mouse lung fibroblast cells (L929). The in vivo hydrogel formation and in vivo biocompatibility of co-polymer NP hydrogel were also investigated and the results further validate the biocompatible nature of co-polymer NP hydrogel. In conclusion, our mPEG-b-POA-b-mPEG NP hydrogel is able to control the release of incorporated drug for longer duration.     

金丝桃素、叶下珠、茵陈体外抗巨细胞病毒效应的比较

目的:探讨金丝桃素单体、苦味叶下珠水溶液浸出物、茵陈水溶性提取物体外抗人巨细胞病毒(HCMV AD169)的作用.方法:采用细胞病变(CPE)抑制法观察金丝桃素单体、苦味叶下珠水溶液浸出物、茵陈水溶性提取物对HCMV AD169毒株的抑制作用,使用MTT比色法检测细胞的损伤程度,并利用吸光度(A)值评价这三种中药抗HC...