Efficient down-regulation of PKC-α gene expression in A549 lung cancer cells mediated by antisense oligodeoxynucleotides in dendrosomes

Multicompartment colloid systems with lipid and polymer membranes for biomedical applications

Multicompartment structures have the potential for biomedical applications because they can act as multifunctional systems and provide simultaneous delivery of drugs and diagnostics agents of different types. Moreover, some of them mimic biological cells to some extent with organelles as separate sub-compartments. This article analyses multicompartment colloidal structures with smaller sub-units covered with lipid or polymer membranes that provide additional protection for the encapsulated substances. Vesosomes with small vesicles encapsulated in the inner pools of larger liposomes are the most studied systems to date. Dendrimer molecules are enclosed by a lipid bilayer shell in dendrosomes. Capsosomes, polymersomes-in-polymer capsules, and cubosomes-in-polymer capsules are composed of sub-compartments encapsulated within closed multilayer polymer membranes. Janus or Cerberus emulsions contain droplets composed of two or three phases: immiscible oils in O/W emulsions and aqueous polymer or salt solutions that are separated into two or three phases and form connected droplets in W/O emulsions. In more cases, the external surface of engulfed droplets in Janus or Cerberus emulsions is covered with a lipid or polymer monolayer. eLiposomes with emulsion droplets encapsulated into a bilayer shell have been given little attention so far, but they have very great prospects. In addition to nanoemulsion droplets, solid lipid nanoparticles, nanostructured lipid carriers and inorganic nanoparticles can be loaded into eLiposomes. Molecular engineering of the external membrane allows the creation of ligand-targeted and stimuli-responsive multifunctional systems. As a result, the efficacy of drug delivery can be significantly enhanced.

LED Photo-polymerization, a Novel Strategy for Triggered Release Liposomes

LED light is used for many medical and cosmetic applications such as phototherapy and skin rejuvenation. Such physical methods can be combined with drug therapy, such as LED-responsive drug delivery system, the subject of present investigation.

To perform this investigation, a nanoliposome composed of DPPC, DSPE-PEG2000, and DC_8,9PC, was prepared as LED-sensitive systems. Calcein was loaded in the liposomes as a fluorescent probe for drug release studies. Different LED wavelengths (blue, green and red) were used for triggering release of calcein from nanoliposome. Indoor daylight, darkness, and sunlight were applied as controls.

Results showed that liposomes do not release their cargo in darkness, but they released it in response to indoor daylight, sunlight and LEDs, with the blue light showing the highest effect. Results also showed that release of calcein was sensitive to wavelength.

Our results reveal potential of LED-sensitive liposomes for medical and cosmetic applications and that such system can be combined with phototherapy. Such concomitant therapies can increase medical/cosmetic effects and decrease adverse reactions to phototherapy.

Dendrosome mediated topical gene silencing by PLK-1 specific siRNA: implication in treatment of skin cancer in mouse model

Topical application of PLK-1 siRNA bearing dendrosomes on DMBA induced skin papillomas in mice exhibit potent anti-cancer effect. The treatment leads to reduced number and sizes of papillomas.

Nanocomplexes for gene therapy of respiratory diseases: Targeting and overcoming the mucus barrier

Gene therapy, i.e. the delivery and expression of therapeutic genes, holds great promise for congenital and acquired respiratory diseases. Non-viral vectors are less toxic and immunogenic than viral vectors, although they are characterized by lower efficiency. However, they have to overcome many barriers, including inflammatory and immune mediators and cells. The respiratory and airway epithelial cells, the main target of these vectors, are coated with a layer of mucus, which hampers the effective reaching of gene therapy vectors carrying either plasmid DNA or small interfering RNA. This barrier is thicker in many lung diseases, such as cystic fibrosis. This review summarizes the most important advancements in the field of non-viral vectors that have been achieved with the use of nanoparticulate (NP) systems, composed either of polymers or lipids, in the lung gene delivery. In particular, different strategies of targeting of respiratory and airway lung cells will be described. Then, we will focus on the two approaches that attempt to overcome the mucus barrier: coating of the nanoparticulate system with poly(ethylene glycol) and treatment with mucolytics. Our conclusions are: 1) Ligand and physical targeting can direct therapeutic gene expression in specific cell types in the respiratory tract; 2) Mucopenetrating NPs are endowed with promising features to be useful in treating respiratory diseases and should be now advanced in pre-clinical trials. Finally, we discuss the development of such polymer- and lipid-based NPs in the context of in vitro and in vivo disease models, such as lung cancer, as well as in clinical trials.

Strategy for selecting nanotechnology carriers to overcome immunological and hematological toxicities challenging clinical translation of nucleic acid-based therapeutics

INTRODUCTION

Clinical translation of nucleic acid-based therapeutics (NATs) is hampered by assorted challenges in immunotoxicity, hematotoxicity, pharmacokinetics, toxicology and formulation. Nanotechnology-based platforms are being considered to help address some of these challenges due to the nanoparticles' ability to change drug biodistribution, stability, circulation half-life, route of administration and dosage. Addressing toxicology and pharmacology concerns by various means including NATs reformulation using nanotechnology-based carriers has been reviewed before. However, little attention was given to the immunological and hematological issues associated with nanotechnology reformulation.

AREAS COVERED

This review focuses on application of nanotechnology carriers for delivery of various types of NATs, and how reformulation using nanoparticles affects immunological and hematological toxicities of this promising class of therapeutic agents.

EXPERT OPINION

NATs share several immunological and hematological toxicities with common nanotechnology carriers. In order to avoid synergy or exaggeration of undesirable immunological and hematological effects of NATs by a nanocarrier, it is critical to consider the immunological compatibility of the nanotechnology platform and its components. Since receptors sensing nucleic acids are located essentially in all cellular compartments, a strategy for developing a nanoformulation with reduced immunotoxicity should first focus on precise delivery to the target site/cells and then on optimizing intracellular distribution.

Storage stability of optimal liposome-polyethylenimine complexes (lipopolyplexes) for DNA or siRNA delivery

The delivery of nucleic acids such as DNA or siRNA still represents a major hurdle, especially with regard to possible therapeutic applications in vivo. Much attention has been focused on the development of non-viral gene delivery vectors, including liposomes or cationic polymers. Among them, polyethylenimines (PEIs) have been widely explored for the delivery of nucleic acids and show promising results. The combination of cationic polymers and liposomes (lipopolyplexes) for gene delivery may further improve their efficacy and biocompatibility, by combining the favourable properties of lipid systems (high stability, efficient cellular uptake, low cytotoxicity) and PEIs (nucleic acid condensation, facilitated endosomal release). In this study, we systematically analyse various conditions for the preparation of liposome-polyethylenimine-based lipopolyplexes with regard to biological activity (DNA transfection efficacy, siRNA knockdown efficacy) and physicochemical properties (size, zeta potential, stability). This includes the exploration of lipopolyplex compositions containing different liposomes and different relevant branched or linear low-molecular-weight PEIs. We establish optimal parameters for lipopolyplex generation, based on various PEIs, N/P ratios, lipids, lipid/PEI ratios and preparation conditions. Importantly, we also demonstrate that certain lipopolyplexes retain their biological activity and physicochemical integrity upon prolonged storage, even at 37°C and/or in the presence of serum, thus providing formulations with considerably higher stability as compared to polyplexes. In conclusion, we establish optimal liposome-polyethylenimine lipopolyplexes that allow storage under ambient conditions. This is the basis and an essential prerequisite for novel, promising and easy-to-handle formulations for possible therapeutic applications.

FZD1 activates protein kinase C delta-mediated drug-resistance in multidrug-resistant MES-SA/Dx5 cancer cells

Multidrug-resistant (MDR) cancer is a major clinical problem in chemotherapy of cancer patients. We have noted inappropriate PKCδ hypomethylation and overexpression of genes in the PKCδ/AP-1 pathway in the human uterus sarcoma drug-resistant cell line, MES-SA/Dx5 cells, which also overexpress p-glycoprotein (ABCB1). Recent studies have indicated that FZD1 is overexpressed in both multidrug-resistant cancer cell lines and in clinical tumor samples. These data have led us to hypothesize that the FZD1-mediated PKCδ signal-transduction pathway may play an important role in drug resistance in MES-SA/Dx5 cells. In this work, the PKCδ inhibitor Rottlerin was found to reduce ABCB1 expression and to inhibit the MDR drug pumping ability in the MES-SA/Dx5 cells when compared with the doxorubicin-sensitive parental cell line, MES-SA. PKCδ was up-regulated with concurrent up-regulation of the mRNA levels of the AP-1-related factors, c-JUN and c-FOS. Activation of AP-1 also correlated with up-regulation of the AP-1 downstream genes HGF and EGR1. Furthermore, AP-1 activities were reduced and the AP-1 downstream genes were down-regulated in Rottlerin-treated or PKCδ shRNA-transfected cells. MES-SA/Dx5 cells were resensitized to doxorubicin-induced toxicity by co-treatment with doxorubicin and Rottlerin or PKCδ shRNA. In addition, cell viability and drug pump-out ability were significantly reduced in the FZD1 inhibitor curcumin-treated and FZD1 shRNA-knockdown MES-SA/Dx5 cells, indicating involvement of PKCδ in FZD1-modulated ABCB1 expression pathway. Taken together, our data demonstrate that FZD1 regulates PKCδ, and the PKCδ/AP-1 signalling transduction pathway plays an important role in drug resistance in MES-SA/Dx5 cells.

Poly(amidoamine) dendrimer nanocarriers and their aerosol formulations for siRNA delivery to the lung epithelium

Small interfering RNA (siRNA)-based therapies have great promise in the treatment of a number of prevalent pulmonary disorders including lung cancer, asthma and cystic fibrosis. However, progress in this area has been hindered due to the lack of carriers that can efficiently deliver siRNA to lung epithelial cells, and also due to challenges in developing oral inhalation (OI) formulations for the regional administration of siRNA and their carriers to the lungs. In this work we report the ability of generation four, amine-terminated poly(amidoamine) (PAMAM) dendrimer (G4NH2)–siRNA complexes (dendriplexes) to silence the enhanced green fluorescent protein (eGFP) gene on A549 lung alveolar epithelial cells stably expressing eGFP. We also report the formulation of the dendriplexes and their aerosol characteristics in propellant-based portable OI devices. The size and gene silencing ability of the dendriplexes was seen not to be a strong function of the N/P ratio. Silencing efficiencies of up to 40% are reported. Stable dispersions of the dendriplexes encapsulated in mannitol and also in a biodegradable and water-soluble co-oligomer were prepared in hydrofluoroalkane (HFA)-based pressurized metered-dose inhalers (pMDIs). Their aerosol characteristics were very favorable, and conducive to deep lung deposition, with respirable fractions of up to 77%. Importantly, siRNA formulated as dendriplexes in pMDIs was shown to keep its integrity after the particle preparation processes, and also after long-term exposures to HFA. The relevance of this study stems from the fact that this is the first work to report the formulation of inhalable siRNA with aerosol properties suitable to deep lung deposition using pMDIs devices that are the least expensive and most widely used portable inhalers. This study is relevant because, also for the first time, it shows that siRNA–G4NH2 dendriplexes can efficiently target lung alveolar epithelial A549 cells and silence genes even after siRNA has been exposed to the propellant environment.

Fused polypeptide with DEF induces apoptosis of lung adenocarcinoma cells

To analyze the effects of a new unknown peptide DEF on the growth of tumor cells, a fused polypeptide TAT-DV1-DEF was designed and synthesized. The lung adenocarcinoma cell line GLC-82 treated with TAT- DV1-DEF was analyzed with a cell counting kit 8, and the location of polypeptides in cells was observed under laser confocal microscopy. The efficiency of polypeptide transfection and changes in nuclear morphology were analyzed by flow cytometry and fluorescence microscopy, respectively. Finally, the mechanism of tumor cell growth inhibition was evaluated by Western blotting. We found that TAT-DV1-DEF could significantly inhibit the growth of the lung adenocarcinoma cell line GLC-82, but not the normal human embryonic kidney cell line HEK-293. Polypeptides were found to be mostly localized in the cytoplasm and some mitochondria. The efficiency of polypeptide transfection in the two cell types was approximately 99%. Apoptotic nuclei were observed under fluorescence microscopy upon treatment with polypeptides and DAPI staining. Western blot analyses indicated that the polypeptide inhibition of tumor cell growth was apoptosis dependent. In the present study, we demonstrated that fused polypeptides could induce apoptosis of the lung adenocarcinoma cell line GLC-82, indicating that the new unknown peptide DEF has antitumor effects.