In this study, novel prodrug-modified cationic liposome nanocomplexes (Combo NCs) were reported for gemcitabine (GEM) and docetaxel (DTX) co-delivery. This nanoplatform exhibited multiple favorable characteristics, such as a ‘green’ fabrication with a one-step chemical reaction, appropriate size (∼200 nm) and distribution (PDI < 0.2), low zeta potential (−31.1 mv), high drug-loading efficiency (9.3% GEM plus 3.1% DTX, wt%) and pH and enzymatic dual-stimulus-responsive release properties. Immunofluorescence and cellular uptake studies showed that Combo NCs efficiently targeted overexpressed CD44 in MDA-MB-231 carcinoma. In vitro studies revealed that Combo NCs played a critical role in the synergistic induction of cytotoxicity, apoptosis and inhibition of wound healing. Combo NCs were confirmed to exhibit great potency for increasing S phase arrest and remodeling the CDA and dCK balance by decreasing the mRNA expression of CDA down to 0.09-fold and increasing the mRNA expression of dCK by 1.36-fold, remarkably increasing the dCK/CDA ratio to 15.3-fold compared with the blank control. The biodistribution results obtained in vivo revealed an effective accumulation in tumor foci. All of these advantages of Combo NCs contributed to their remarkable anti-tumor efficacy without systemic toxicity as well as their apoptosis-enhancing and anti-proliferative capacities, as determined by TUNEL and Ki67 immunohistochemistry in vivo. Consequently, such a rationally contemplated co-delivery system demonstrated the promising potential of clinical applications for triple-negative breast cancer therapy.State of SignificanceThe Combo NCs were innovatively applied for co-delivery of hydrophilic GEM and hydrophobic DTX. The ester bond linking and shielding effect of HA-GEM made the carriers achieve synchronous release properties, which was determined in in vitro release study. Due to the HA modification, the vectors own great potency for positive targeting to CD44 overexpressed triple-negative breast cancer cells MDA-MB-231. Cytotoxicity and apoptosis studies confirmed the targeting effect and synergism between two drugs. Interestingly, we found in cell cycle study, drug combinations (free combination or Combo NCs) didn’t show a rise in G2M phase, which was significantly higher when treated DTX alone. We further discovered the role of DTX in combinations may involve in modulating GEM associated enzymes thus enhancing the efficacy of GEM. Consequently, this nanoplatform provided a novel solution for achieving targeted co-delivery and potentiating effect in cancer therapy.Download high-res image (127KB)Download full-size image

•A pH-sensitive liposome was successfully constructed containing CHEMS-anchored PEG2000.•DTX/NGR-PLL possessed appropriate diameter, ζ-potential, and encapsulation efficiency.•Liposome had good pH sensitivity so it can be delivered rapidly into tumor cells.•Actively targeting of CD13 receptors enhanced the specific targeting and antitumor activity.•NGR-modified liposomes can significantly and safely accumulate in tumor tissue.As current tumor chemotherapy faces many challenges, it is important to develop drug delivery systems with increased tumor-targeting ability, enhanced therapeutic effects and reduced side effects. In this study, a pH-sensitive liposome was constructed containing CHEMS-anchored PEG2000 for extended circulation and NGR peptide as the targeting moiety. The NGR-modified docetaxel-loaded pH-sensitive extended-circulation liposomes (DTX/NGR-PLL) prepared possess suitable physiochemical properties, including particle size of approximately 200 nm, drug encapsulation efficiency of approximately 70%, and pH-sensitive drug release properties. Experiments performed in vitro and in vivo on human fibrosarcoma cells (HT-1080) and human breast adenocarcinoma cells (MCF-7) verified the specific targeting ability and enhanced antitumor activity to HT-1080 cells. The results of intravenous administration demonstrated that NGR-modified liposomes can significantly and safely accumulate in tumor tissue in xenografted nude mice. In conclusion, the liposomes constructed hold promise as a safe and efficient drug delivery system for specific tumor treatment.Download high-res image (189KB)Download full-size imageSchematic representation of the toxicity mechanism of DTX/NGR-PLL.Abbreviations: DTX, docetaxel; CHEMS, cholesteryl hemisuccinate; PEG, poly (ethylene glycol).

•RGD modified docetaxel liposomes were successfully prepared and characterized.•The liposomes exhibited slow-release properties and pH-sensitive release behavior.•The prepared liposomes showed enhanced cytotoxicity and cellular uptake in vitro.•In vivo studies have confirmed prepared liposomes have enhanced tumor targeting and improved antitumor efficacy.The goal of this research was to formulate dual-targeting liposomes (RGD/DTX-PSL) that can selectively release loaded contents in a low pH level environment and to actively target to the tumor using liposomes that had surface arginine-glycine-aspartic (RGD) tripeptides. We investigated whether RGD/DTX-PSL could serve as an effective tumor-targeted nanoparticle that is capable of suppressing tumor growth. The results suggest that DTX is released from liposomes faster at pH 5.0 than pH 7.4, demonstrating their pH sensitivity. RGD/DTX-PSL has a longer blood circulation than Duopafei® in rats. The RGD/DTX-PSL formulation displayed stronger antiproliferative effects than DTX alone and the strongest inhibition of tumor growth of the formulations tested, thus expanding therapeutic window of DTX. In conclusion, we established a novel, promising and easy-to-handle liposome formulation that has a considerable antitumor activity in vitro and in vivo. This study provides important prerequisite for the clinical application of dual-targeting liposomes in delivering therapies.

The massive amount of human genetic information already available has accelerated the identification of target genes, making gene and nucleic acid therapy the next generation of medicine. Nanoparticle (NP)-based anticancer gene therapy treatment has received significant interest in this evolving field. Recent advances in vector technology have improved gene transfection efficiencies of nonviral vectors to a level similar to viruses. This review serves as an introduction to surface modifications of NPs based on polymeric structural improvements and target moieties. A discussion regarding the future perspective of multifunctional NPs in cancer therapy is also included.

The metabolic activity of organisms can be measured by recording the heat output using microcalorimetry. In this paper, the total alkaloids in the traditional Chinese medicine Radix Aconiti Lateralis were extracted and applied to Escherichia coli and Staphylococcus aureus. The effect of alkaloids on bacteria growth was studied by microcalorimetry. The power-time curves were plotted with a thermal activity monitor (TAM) air isothermal microcalorimeter and parameters such as growth rate constant (µ), peak-time (Tm), inhibitory ratio (I), and enhancement ratio (E) were calculated. The relationships between the concentration of Aconitum alkaloids and µ of E. coli or S. aureus were discussed. The results showed that Aconitum alkaloids had little effect on E. coli and had a potentially inhibitory effect on the growth of S. aureus.研究附子生物碱对大肠杆菌和金黄色葡萄球菌生长代谢作用的影响, 并对其抗菌活性进行评价。首次应用微量热的方法研究了大肠杆菌和金黄色葡萄球菌在附子生物碱中的生长代谢作用, 并从热力学角度对附子生物碱的抗菌活性进行了评价。微量量热仪绘制了37 °C 时大肠杆菌和金黄色葡萄球菌在不同浓度的附子生物碱作用下的热谱曲线, 根据热动力学模型, 分别得到了生长速率常数µ、抑制率I、最大产热功率Pm以及最大产热功率所对应的时间Tm 等热动力学参数, 从热动力学的角度探讨了附子生物碱对大肠杆菌和金黄色葡萄球菌代谢作用的影响。实验结果显示, 附子生物碱对大肠杆菌的生长代谢基本没有影响。但是对于金黄色葡萄球菌, 随着附子生物碱浓度的增大, 其生长速率常数呈现先升高后降低的趋势, 同时达峰时间也被延长, 说明附子生物碱对金黄色葡萄球菌存在潜在的生长抑制作用。

Docetaxel (DTX), as a member of taxoid family, has been widely used in the treatment of cancers. The present study prepared pH-sensitive DTX-loaded liposomes (DTX-Lips) by thin-film dispersion method and various physico-chemical and morphological properties were examined. The pH sensitivity of in vitro DTX release and the in vivo pharmacokinetics and tissue distribution using Kunming mice were also investigated. The mean particle size and zeta potential of DTX liposomes were (277±2) nm and (−32.60±0.26) mV, respectively. Additionally, in vitro drug release study showed that the cumulative release rate was 1.3 times more at pH 5.0 than at pH 7.4, suggesting a pH-dependent release ability of DTX-Lips. Pharmacokinetic and pharmaceutical studies in comparison with Duopafei® showed that the half-time period (t1/2) and area under the curve (AUC) of DTX-Lips in mouse plasma were 1.8 times longer and 2.6 times higher, respectively, and that DTX-Lips selectively accumulated in macrophage-rich organs such as liver and spleen. These results together suggest that the DTX-Lips could be a promising formulation for the clinical administration of DTX.

•pH sensitive liposomes (contain OA, LA and CHEMS) were successfully prepared and characterized.•ζ-potential, diameter and TEM data showed good stability of the PSLs under neutral conditions.•Nano-DSC results showed cholesterol or CHEMS can stabilize the liposomes.•All of the three liposomes had good pH sensitivity and CHEMS showed stronger pH-sensitive property.Currently, the phosphatidylethanolamine-based, pH-sensitive, liposome drug-delivery system has been widely developed for efficient, targeted cancer therapy. However, the mechanism of pH sensitivity was unclear; it is a main obstacle in controlling the preparation of pH-sensitive liposomes (PSLs).Therefore, our research is aimed at clarifying the pH-response mechanism of the various molecules that compose liposomes. We chose the small pH-sensitive molecules oleic acid (OA), linoleic acid (LA) and cholesteryl hemisuccinate (CHEMS) and the fundamental lipids cholesterol and phosphatidylethanolamine (PE) as test molecules. The PSLs were prepared using the thin-film hydration method and characterized in detail at various pH values (pH 5.0, 6.0 and 7.4), including particle size, ζ-potential, drug encapsulation efficiency and drug loading. The surface structure was observed by transmission electron microscopy (TEM), and the electrical conductivity of the liposome dispersion was also tested. The calorimetric analysis was conducted by Nano-differential scanning calorimetry (Nano-DSC). The in vitro drug release profile showed that PSLs exhibit good pH sensitivity. At neutral pH, the particle size was approximately 150 nm, and it dramatically increased at pH 5.0. The ζ-potential increased as the pH decreased. The Nano-DSC results showed that cholesterol and CHEMS can both increase the stability and phase transfer temperature of PSLs. Conductivity increased to a maximum at pH 5.0 and was rather low at pH 7.4. In conclusion, results show that the three kinds of liposomes have pH responsive release characteristics in acidic pH. The OA-PSLs have a pH sensitive point of 5. Since CHEMS has a cholesterol-like structure, it can stabilizes the phospholipid bilayer under neutral conditions as shown in the Nano-DSC data, and because it has a special steroidal rigid structure, it exhibits better pH response characteristics under acidic conditions.