PEGylated Prussian blue nanocubes as a theranostic agent for simultaneous cancer imaging and photothermal therapy

Theranostic agents with both imaging and therapeutic functions have attracted enormous interests in cancer diagnosis and treatment in recent years. In this work, we develop a novel theranostic agent based on Prussian blue nanocubes (PB NCs), a clinically approved agent with strong near-infrared (NIR) absorbance and intrinsic paramagnetic property, for invivo bimodal imaging-guided photothermal therapy. After being coated with polyethylene glycol (PEG), the obtained PB-PEG NCs are highly stable in various physiological solutions. Invivo T1-weighted magnetic resonance (MR) and photoacoustic tomography (PAT) bimodal imaging uncover that PB-PEG NCs after intravenous (i.v.) injection show high uptake in the tumor. Utilizing the strong and super stable NIR absorbance of PB, invivo cancer treatment is then conducted upon i.v. injection of PB-PEG NCs followed by NIR laser irradiation of the tumors, achieving excellent therapeutic efficacy in a mouse tumor model. Comprehensive blood tests and careful histological examinations reveal no apparent toxicity of PB-PEG NCs to mice at our tested dose, which is two-fold of the imaging/therapy dose, within two months. Our work highlights the great promise of Prussian blue with well engineered surface coating as a multifunctional nanoprobe for imaging-guided cancer therapy. ? 2014 Elsevier Ltd

PEGylated WS2 nanosheets as a multifunctional theranostic agent for in vivo dual-modal CT/photoacoustic imaging guided photothermal therapy

A new generation of photothermal theranostic agents is developed based on PEGylated WS2 nanosheets. Bimodal in vivo CT/photoacoustic imaging reveals strong tumor contrast after either intratumoral or intravenous injection of WS2-PEG. In vivo photothermal treatment is then conducted in a mouse tumor model, achieving excellent therapeutic efficacy with complete ablation of tumors. This work promises further exploration of transition-metal dichalcogenides for biomedical applications, such as cancer imaging and therapy. ? 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

响应面法优化重组谷氨酸棒杆菌G-BC 产脂肪酸的培养条件Optimization of culture conditions for fatty acid production of recombinant Corynebacterium glutamicum G-BC by response surface methodology

乙酰辅酶A羧化酶是谷氨酸棒杆菌中调控脂肪酸合成的关键酶。为了研究乙酰辅酶A羧化酶α亚基（accBC）基因对脂肪酸合成的影响，以accBC表达的菌株重组谷氨酸棒杆菌G-BC为材料，研究了诱导剂异丙基-β-D-硫代半乳糖苷（IPTG）浓度、培养时间、培养温度对重组谷氨酸棒杆菌G-BC脂肪酸产量的影响，并通过响应面法优化了重组谷氨酸棒杆菌G-BC产脂肪酸的培养条件，同时与原始菌株脂肪酸产量进行了对比。结果表明：重组谷氨酸棒杆菌G-BC产脂肪酸的最佳条件为诱导剂浓度1 mmol/L 、培养时间20 h、培养温度32 ℃，在此条件下脂肪酸产量为34.56 mg/g（以菌体干质量计），比原始菌株提高了1.68倍。说明乙酰辅酶A羧化酶α亚基对于谷氨酸棒杆菌合成脂肪酸有促进作用。 Acetyl-CoA carboxylase is a key enzyme regulating fatty acid synthesis in Corynebacterium glutamicum. In order to study the effect of acetyl-CoA carboxylase α subunit (accBC) gene on fatty acid synthesis,the recombinant Corynebacterium glutamicum G-BC(expression strain of accBC) was used as raw material, the effects of inducer(isopropyl-β-D-thiogalactopyranoside,IPTG) concentration, culture time and culture temperature on the yield of fatty acid were studied. Moreover, the culture conditions for fatty acid production of recombinant Corynebacterium glutamicum G-BC were optimized by response surface methodology. The fatty acid yield of the original strain and the recombinant strain was also compared.The results showed that the optimal culture conditions were obtained as follows: inducer concentration 1 mmol/L, culture time 20 h, and culture temperature 32 ℃. Under these conditions, the yield of fatty acid was 34.56 mg/g（based on dry weight of bacteria）, which was 1.68 times higher than original strain. The accBC can promote the synthesis of fatty acid by Corynebacterium glutamicum

天然抗氧化剂对黄油氧化稳定性的影响Effects of natural antioxidants on oxidative stability of butter

为给黄油中复配天然抗氧化剂的开发提供思路，通过DPPH法测定DPPH自由基清除率和Rancimat法测定氧化诱导时间，研究单一和复配添加α-生育酚、γ-谷维素和植物甾醇3种天然抗氧化剂对黄油氧化稳定性的影响。结果表明：3种天然抗氧化剂均能提高黄油的氧化稳定性；不同复配组合对黄油氧化稳定性的影响有差异，其中α-生育酚和γ-谷维素（125 mg/kg和1 250 mg/kg）、α-生育酚和植物甾醇（125 mg/kg和1 250 mg/kg）、γ-谷维素和植物甾醇（均为800 mg/kg）3种复配组合对黄油氧化稳定性的提升较大，特别是α-生育酚和γ-谷维素（125 mg/kg和1 250 mg/kg）组合的氧化诱导时间可提升3.70 h，DPPH自由基清除率达80.4%，氧化稳定性能优于其他复配组合。综上，将复配天然抗氧化剂添加到黄油中可提高其氧化稳定性。 To provide ideas for the development of compounded natural antioxidants in butter, DPPH radical scavenging rate was evaluated by DPPH method and oxidation induction time was analyzed by Rancimat method. The effects of single or compound addition of three natural antioxidants, α-tocopherol, γ-oryzanol and phytosterol on oxidative stability of butter were investigated. The results showed that all three natural antioxidants could enhance oxidative stability of butter, and different combinations had different effects on oxidative stability of butter. With the three combinations of α-tocopherol and γ-oryzanol (125 mg/kg and 1 250 mg/kg), α-tocopherol and phytosterol (125 mg/kg and 1 250 mg/kg), and γ-oryzanol and phytosterol (both 800 mg/kg) showed greater improvement in the oxidative stability of butter. In particular, the oxidation induction time of group α-tocopherol and γ-oryzanol (125 mg/kg and 1 250 mg/kg) could be increased by 3.70 h, and the DPPH radical scavenging rate reached 80.4%, and the oxidative stability was better than other combinations. In conclusion, the addition of the compounded natural antioxidants to butter can improve its oxidative stability