Imaging Cancer Cells Expressing the Folate Receptor with Carbon Dots Produced from Folic Acid

Development of new imaging tools for cancer cells in vitro and in vitro is important for advancing cancer research, elucidating drug effects upon cancer cells, and studying cellular processes. We showed that fluorescent carbon dots (C‐dots) synthesized from folic acid can serve as an effective vehicle for imaging cancer cells expressing the folate receptor on their surface. The C‐dots, synthesized through a simple one‐step process from folic acid as the carbon source, exhibited selectivity towards cancer cells displaying the folate receptor, making such cells easily distinguishable in fluorescence microscopy imaging. Biophysical measurements and competition experiments both confirmed the specific targeting and enhanced uptake of C‐dots by the folate receptor‐expressing cells. The folic acid‐derived C‐dots were not cytotoxic, and their use in bioimaging applications could aid biological studies of cancer cells, identification of agonists/antagonists, and cancer diagnostics.     

Folate-Equipped Nanolipoplexes Mediated Efficient Gene Transfer into Human Epithelial Cells

Since recombinant viral vectors have been associated with serious side effects, such as immunogenicity and oncogenicity, synthetic delivery systems represent a realistic alternative for achieving efficacy in gene therapy. A major challenge for non-viral nanocarriers is the optimization of transgene expression in the targeted cells. This goal can be achieved by fine-tuning the chemical carriers and the adding specific motifs to promote cellular penetration. Our study focuses on the development of novel folate-based complexes that contain varying quantities of folate motifs. After controlling for their physical properties, neutral folate-modified lipid formulations were compared in vitro to lipoplexes leading to comparable expression levels. In addition, no cytotoxicity was detected, unlike what was observed in the cationic controls. Mechanistically, the delivery of the transgene appeared to be, in part, due to endocytosis mediated by folate receptor targeting. This mechanism was further validated by the observation that adding free folate into the medium decreased luciferase expression by 50%. In vivo transfection with the folate-modified MM18 lipid, containing the highest amount of FA-PEG₅₇₀-diether co-lipid (w:w; 90:10), at a neutral charge ratio, gave luciferase transgene expression. These studies indicate that modification of lipids with folate residues could enhance non-toxic, cell-specific gene delivery.     

NiFe2O4@SiO2–PPA Nanoparticle: A Green Nanocatalyst for the Synthesis of β-Acetamido Ketones

ABSTRACT

In this work, silica coated magnetic nanoparticles of modified polyphosphoric acid (NiFe₂O₄@SiO₂–PPA deigned as NFS–PPA) represent as a reusable and green catalyst for one-pot four-component synthesis of β-acetamido ketones at room temperature under solvent-free conditions. This catalyst was synthesized and characterized by X-ray diffractions, transmission electron microscopy, scanning electron microscopy and vibrating sample magnetometry. The magnetic catalyst can be easily removed by a simple magnet and reused up to five times without any loss of its high catalytic activity. In addition to facility, this protocol enhances product purity and promises economic and also environmental profits.     

Highly selective purification of ferulic acid from wheat bran using deep eutectic solvents modified magnetic nanoparticles

Fe₃O₄ nanoparticles (Fe₃O₄NPs) were prepared by chemical coprecipitation. Deep eutectic solvents (DESs) (ChCl/glycol, 1/2, n/n) were used to modify Fe₃O₄NPs. The obtained Fe₃O₄NPs and DESs–Fe₃O₄NPs were applied for purification of ferulic acid from wheat bran by magnetic solid-phase extraction (MSPE). The satisfactory extraction recoveries for ferulic acid (88.7%) were obtained by changing different washing and eluted solvents. The recovery of the proposed method at three spiked level analysis was 77.9–97.5%, with the relative standard deviation less than 4.5%. DESs–Fe₃O₄NPs showed good performance for ferulic acid and the proposed approach might offer a novel method for purifying complex samples.     

Tumour Cell Labelling by Magnetic Nanoparticles with Determination of Intracellular Iron Content and Spatial Distribution of the Intracellular Iron

Magnetically labelled cells are used for in vivo cell tracking by MRI, used for the clinical translation of cell-base therapies. Studies involving magnetic labelled cells may include separation of labelled cells, targeted delivery and controlled release of drugs, contrast enhanced MRI and magnetic hyperthermia for the in situ ablation of tumours. Dextran-coated super-paramagnetic iron oxide (SPIO) ferumoxides are used clinically as an MR contrast agents primarily for hepatic imaging. The material is also widely used for in vitro cell labelling, as are other SPIO-based particles. Our results on the uptake by human cancer cell lines of ferumoxides indicate that electroporation in the presence of protamine sulphate (PS) results in rapid high uptake of SPIO nanoparticles (SPIONs) by parenchymal tumour cells without significant impairment of cell viability. Quantitative determination of cellular iron uptake performed by colorimetric assay is in agreement with data from the literature. These results on intracellular iron content together with the intracellular distribution of SPIONs by magnetic force microscopy (MFM) following in vitro uptake by parenchymal tumour cells confirm the potential of this technique for clinical tumour cell detection and destruction.     

叶酸精制工艺的改进

提出了一种叶酸精制的方法。先采用30％硫酸对叶酸粗品进行精制，然后用液碱进行二次精制，总收率可达53．0％，产品质量符合中国药典、美国药典、英国药典的要求，并且可以降低原料成本。     

催化加氢合成对氨基苯甲酰谷氨酸新工艺研究

研究了以对硝基苯甲酰谷氨酸为原料,经催化加氢合成对氨基苯甲酰谷氨酸,得到了优惠反应条件,催化剂进行了循环套用。     

HPLC法测定叶酸片溶出度

采用高效液相色谱（HPLC）法进行叶酸片的溶出度测定。采用小杯法,色谱柱为Agilent Hypersil C18（25 cm×4.6 nm,5μm）,流动相为pH=5.0的磷酸盐缓冲液,检测波长为280 nm,流速为1.2 mL/min。结果表明,采用HPLC法测定叶酸片溶出度,分离度好,峰形对称,保留时间短,辅料不干扰,测得叶酸回收率为100.6%,RSD=1.04%（n=9）。该法简便,结果准确。     

利用山梨酸合成香料叶醇

叶醇及酯是重要而名贵的香料 ,可由山梨酸为原料通过化学合成的方法得到。山梨酸在无水乙醚溶液中用 Li Al H4作还原剂在 2 6～ 30°C下反应 1 .5 h,然后在 Mo( CO) 6的存在下在高压反应釜中进行选择性氢化反应 ,在温度 1 2 0～ 1 40°C下反应 5～ 6h即得产品