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In the last decades, gene therapy has become a novel therapeutic strategy for cancer treatment, including immunologic and molecular approaches. Among molecular avenue, the design of efficient and effective gene delivery systems, like cationic liposomes and niosomes, has been widely investigated and proposed as the most promising research area. The advantages of cationic vesicles rely on their natural ability to form complexes with anionic genetic molecules and deliver them into the cells via the endosomal pathway. Obviously, cationic vesicles- mediated gene delivery is affected by numerous factors, in particular composition, that strongly affects vesicle physical-chemistry characteristics and transfection effectiveness. This review will analyse the potential of cationic nanocarriers in cancer gene therapy, focusing on the role of liposomes and niosomes as vesicular devices and giving an exhaustive collection of the most representative investigations., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

Delivering chemotherapy specifically, effectively and safely to tumor remains a significant challenge in recent years. Although cancer cells are more vulnerable than normal to the effect of anticancer agents, these drugs are non-selective and can cause injury to normal tissues. Different approaches i.e. passive, active and magnetic targeting, smart devices with appropriate stimuli-sensitive properties or drugs combinations, have been already proposed as single methods, contributing to minimize severe side effects and enhancing tumor-targeting efficacy. Often, the use of a single strategy is not sufficient, whereby multi-functional approach has been suggested as further evolution of traditional "magic bullet" proposed in the early 1900s by Paul Ehrlich. Among the macromolecular systems useful for targeted drug delivery, liposomes and niosomes are the most extensively studied and they own the most suitable characteristics to be converted in multi-functional devices. Liposomes and niosomes are nanovesicles that contain amphiphilic molecules arranged in concentric bilayers, delimitating an aqueous core. These vesicular carriers are very versatile, since they can be differently designed and modified in such a way that they exhibit combinations of the following properties: longevity in blood, specific target to the tumor, respond to internal/external stimuli, promotion of drug intracellular delivery. This review will focus on the potential of multi-functional vesicular nanocarriers in cancer therapy, analizing each combination of targeting strategies, stimuli-sensitivity and drug combinations and giving an exhaustive collection of recent investigations. Many multi-functional vesicular devices have shown great promise in clinical application, indicating broad potential as therapeutics in the near future, but more needs to be done. The development of more specific and efficient carriers for a personalized cancer therapy is the next challenge., (Copyright © 2016 Elsevier B.V. All rights reserved.)

The loading of chemotherapics into smart nanocarriers that simultaneously possess more than one useful property for specifically targeting a tumor site improves their therapeutic effectiveness, reducing their side effects. Hence, we proposed a combined approach for the treatment of human breast cancer (BC) consisting of the co-encapsulation of doxorubicin and curcumin or doxorubicin and quercetin into multifunctional niosomes, which results in prolonged blood circulation and an ability to spontaneously accumulate at the tumor site (passive target) and to recognize and bind the tumor cells through dual ligand-receptor interactions (active target). The drug-loaded vesicles showed high stability and good capability of loading doxorubicin and antioxidants alone or in combination. Their diameter was around 400 nm. The drugs released from the vesicles were found to be controlled and sustained for over 24 h, with a strong dependence on the co-presence of the loaded molecules. Transferrin and/or folic acid were conjugated on the external surface of the niosomes as ligands, considerably improving the cellular uptake into MCF-7 and MDA-MB-231 malignant cells when compared with the uptake of nonconjugated samples. In vitro evaluation of anticancer activity demonstrated the strong potential of niosomes loaded with a doxorubicin/curcumin combination as useful devices in breast tumor treatment. These features hold great promise for the development of multifunctional devices that combine several advantages such as biocompatibility, stealth properties, loading capability, and active targeting, moving toward the development of more specific and efficient carriers for personalized tumoral therapy.

We designed novel niosomes based on alkyl glucopyranoside surfactants and containing methotrexate as anticancer drug, to be used in the pharmaceutical field. The effects of surfactants with chains of different length on niosome size and their distribution, drug entrapment efficiencies and in vitro drug release were determined. Systems made of alkyl glucopyranosides and cholesterol form vesicles whose average size scales with the alkyl chains length of such surfactants. Vesicles size ranges between 300 and 500 nm, with low polydispersity index. In addition, the hemolytic activity of alkyl glucopyranosides as surfactant solutions or vesicular formulations was studied and compared, to identify possible structure-activity relationships. High methotrexate entrapment efficiency was obtained, confirming significant interactions between the drug and the niosomal matrices. After 24h the amount of methotrexate released from niosomal formulations is effectively delayed, compared to the free drug in solution. Hemolytic tests show that sugar-based surfactants are more hemolytic the longer is their alkyl chain. When the surfactants are in vesicular form, the reverse behavior holds. It was also inferred that vesicle formation reduces the surfactant toxicity. These niosomal formulations can be used as methotrexate delivery systems in anticancer therapy., (Copyright © 2013 Elsevier B.V. All rights reserved.)

An efficient tumor-targeted niosomal delivery system for the vehiculation of doxorubicin hydrochloride as an anticancer agent was designed. Niosomes were prepared from a mixture of an opportunely modified Pluronic L64 surfactant and cholesterol as a membrane additive and characterized in terms of size and related distribution function and drug entrapment efficiency. After the preparation, transferrin was conjugated to niosomes to produce transferrin (Tf) niosomes, and the cytotoxicity of the final formulation was studied. The specific uptake of Tf niosomes into cells was evaluated via incubation of MCF-7 and MDA-MB-231 cells with fluorescently rhodamine-loaded Tf niosomes for various times and concentration intervals and further investigated by fluorescence microscopy. Results showed that doxorubicin can be easily encapsulated into niosomes, which are regular and spherical in shape. Moreover, transferrin conjugate niosomes demonstrated far greater extents of cellular uptake by MCF-7 and MDA-MB-231 cells, suggesting that they were mainly taken up by transferrin receptor-mediated endocytosis. Doxorubicin-loaded niosome anticancer activity was also achieved against MCF-7 and MDA-MB-231 tumor cell lines, and a significant reduction in viability in a dose- and time-related manner was observed. Finally, our formulation could be potentially useful as a target doxorubicin delivery system in anticancer therapy.

In this study, liposomes coated with novel multifunctional polymers were proposed as an innovative platform for tumor targeted drug delivery. Novel Folic acid–Cysteine-Thiolated chitosan (FTC) derivatives possessing active targeting ability and redox responsivity were synthesized, characterized, and employed to develop FTC-coated liposomes. Liposomes were characterized for size, surface charge and drug encapsulation efficiency before and after coating. The formation of a coating layer on liposomal surface was confirmed by the slight increase in particle size and by zeta-potential changes. FTC-coated liposomes showed a redox-dependent drug release profile: good stability at physiological conditions and rapid release of liposome-entrapped calcein in presence of glutathione. Moreover, the uptake and cytotoxic activity of doxorubicin-loaded FTC-coated liposomes was evaluated on murine B16-F10 and human SKMEL2 melanoma cancer cells. Results demonstrated enhanced uptake and antitumor efficacy of FTC-coated liposomes compared to control chitosan-coated liposomes in both cancer lines, which is attributed to higher cellular uptake via folate receptor-mediated endocytosis and to triggered drug release by the reductive microenvironment of tumor cells. The proposed novel liposomes show great potential as nanocarriers for targeted therapy of cancer. [ABSTRACT FROM AUTHOR]

The clinical efficacy of methotrexate (MTX) is limited by its poor water solubility, its low bioavailability, and the development of resistance in cancer cells. Herein, we developed novel folate redox-responsive chitosan (FTC) nanoparticles for intracellular MTX delivery. l-Cysteine and folic acid molecules were selected to be covalently linked to chitosan in order to confer it redox responsiveness and active targeting of folate receptors (FRs). NPs based on these novel polymers could possess tumor specificity and a controlled drug release due to the overexpression of FRs and high concentration of reductive agents in the microenvironment of cancer cells. Nanoparticles (NPs) were prepared using an ionotropic gelation technique and characterized in terms of size, morphology, and loading capacity. In vitro drug release profiles exhibited a glutathione (GSH) dependence. In the normal physiological environment, NPs maintained good stability, whereas, in a reducing environment similar to tumor cells, the encapsulated MTX was promptly released. The anticancer activity of MTX-loaded FTC-NPs was also studied by incubating HeLa cells with formulations for various time and concentration intervals. A significant reduction in viability was observed in a dose- and time-dependent manner. In particular, FTC-NPs showed a better inhibition effect on HeLa cancer cell proliferation compared to non-target chitosan-based NPs used as control. The selective cellular uptake of FTC-NPs via FRs was evaluated and confirmed by fluorescence microscopy. Overall, the designed NPs provide an attractive strategy and potential platform for efficient intracellular anticancer drug delivery. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this work is to design, prepare and characterize l-lysine based prodrugs capable of targeting 6-mercaptopurine to the colon, an anti-tumor and immunosuppressant drug, and 5-aminosalicylic acid (5-ASA), drug of choice for inflammatory bowel disease (IBD). More specifically, Nɛ-feruloyl-S-(6-purinyl)-l-lysine and Nɛ-acryloyl-S-(6-purinyl)-l-lysine were synthesized and then characterized by FT-IR, 1H-NMR and GC/MS spectroscopies. The ability of feruloyl derivative in inhibiting lipid peroxidation in rat liver microsomal membranes, induced in vitro by tert-butyl hydroperoxide as source of free radicals, was evaluated. Moreover, Nɛ-acryloyl-S-(6-purinyl)-l-lysine, polymerizable prodrug, was used to microspheres realization for 5-ASA release. These lasts, obtained by emulsion inverse technique, were characterized by light scattering and scanning electron microscopy (SEM) analysis. The microspheres equilibrium swelling degree was evaluated and showed good swelling behaviour in simulating colonic fluids. Results confirm the possibility that the application range of l-lysine prodrug can be extended to the treatment of intestinal diseases whose conventional therapy envisages medications with serious side effects that, thanks to this new strategy, can be minimized in an optimal way. [Copyright &y& Elsevier]