Current Drug Targets (v.16, #14)

Meet Our Editorial Board Member: by Chen Chen (1563-1563).

Targeted Drug Delivery Systems for Lung Macrophages by Ana Costa, Bruno Sarmento, Vítor Seabra (1565-1581).
Lung macrophages present an effective role in innate and immune response through specific and non-specific mechanisms, namely phagocytosis, antigen processing and presentation through major histocompatibility complex, activation of T cells and inflammatory cytokines release. Despite their protective role against injury in normal condition, they can cause several lung conditions, since they can mediate several processes, through recruitment of other inflammatory cells for alveolar space, release of proinflammatory cytokines or stimulation of collagen deposition. Lung macrophages constitute a good therapeutic target. With the development of nanotechnology, new carriers have been designed to target drugs towards these cells. One of the commonly used approaches is the attachment of ligands with affinity to receptors presented at lung macrophage surface, to the nanocarriers. This review will focus on the importance of lung macrophages in host-defense, their influence on different pulmonary diseases and different strategies for alveolar macrophage targeting.

Multistage Nanovectors Enhance the Delivery of Free and Encapsulated Drugs by Jonathan O. Martinez, Michael Evangelopoulos, Rohan Bhavane, Stefania Acciardo, Francesco Salvatore, Xuewu Liu, Mauro Ferrari, Ennio Tasciotti (1582-1590).
Nanoparticles have considerable potential for cancer imaging and therapy due to their small size and prolonged circulation. However, biological barriers can impede the delivery of a sufficient dose of a drug to the target site, thereby also resulting in the accumulation of toxic compounds within healthy tissues, and systemic toxicity. Multistage nanovectors (MSV) preferentially accumulate on inflamed endothelium, and can thus serve as carriers for drugs and nanoparticles. Herein, we describe the loading of free (i.e., melittin) and nano-encapsulated (i.e., doxorubicin-loaded micelles) drugs into MSV, and report the impact of surface charge and pore size on drug loading. For both drug formulations, negatively charged MSV (i.e., oxidized) with larger pores were shown to retain higher concentrations of payloads compared to positively charged (i.e., APTES-modified) MSV with small pores. Treatment of human umbilical vein endothelial cells (HUVEC) with melittin-loaded MSV (MEL@MSV) resulted in an 80% reduction in cell viability after 3 days. Furthermore, MEL@MSV conjugated with antivascular endothelial growth factor receptor 2 (VEGFR2) antibodies displayed preferential targeting and delivery of MEL to activated HUVEC expressing VEGFR2. Treatment of HUVEC and MCF7 cells with doxorubicin-loaded micelles (DOXNP@MSV) resulted in a 23% and 47% reduction in cell viability, respectively. Taken together, these results demonstrate increased loading of a payload in oxidized, large pore MSV, and effective delivery of free and nano-encapsulated drugs to endothelial and cancer cells.

Polysaccharide based Copolymers as Supramolecular Systems in Biomedical Applications by Regina Célia Monteiro de Paula, Judith Pessoa Andrade Feitosa, Haroldo César Beserra Paula (1591-1605).
Polysaccharides are natural polymers, obtained from a large variety of sources ranging from fungi to more complex organisms such as birds and whales. Their use for pharmaceutical and biomedical applications has been the subject of numerous researches by the world's academia. Polysaccharide chemical/physical modifications leading to graft copolymers are discussed in this review, focusing on those nanosystems that are potential candidates for drug delivery applications. Therefore, this review focuses on the biomedical application of polysaccharide based copolymers, particularly as nanocarriers. Copolymer of polysaccharides such as alginate, cellulose, chitosan, dextran, guar, hyaluronic acid, pullulan and starch as drug delivery nanocarriers will be discussed.

The self-assembly of a series of triblock co polymers Pluronics (P85, P105 and L121) has been investigated in some ionic liquids (BMIMBF4, BMIMPF6 and BMIMTf2N) by using Near-Infrared spectroscopy. The formation of supramolecular s tructures has been confirmed by optical microscopy. The solvation degree and the aggregation behaviour of P85, P105 and L121 depend on the interactions between the imidazolium ring of the ionic liquid and the hydrophilic moiety of the copolymer. Fluorescent vesicles can be observed after the incorporation of Nile Red into the polymeric bilayer of L121 or by linking fluorescein isothiocyanate to the copolymer structure.

Influence of the Supramolecular Micro-Assembly of Multiple Emulsions on their Biopharmaceutical Features and In vivo Therapeutic Response by Felisa Cilurzo, Maria Chiara Cristiano, Luisa Di Marzio, Donato Cosco, Maria Carafa, Cinzia Anna Ventura, Massimo Fresta, Donatella Paolino (1612-1622).
The ability of some surfactants to self-assemble in a water/oil bi-phase environment thus forming supramolecular structure leading to the formation of w/o/w multiple emulsions was investigated. The w/o/w multiple emulsions obtained by self-assembling (one-step preparation method) were compared with those prepared following the traditional two-step procedure. Methyl-nicotinate was used as a hydrophilic model drug. The formation of the multiple emulsion structure was evidenced by optical microscopy, which showed a mean size of the inner oil droplets of 6 ?m and 10 ?m for one-step and two-step multiple emulsions, respectively. The in vitro biopharmaceutical features of the various w/o/w multiple emulsion formulations were evaluated by means of viscosimetry studies, drug release and in vitro percutaneous permeation experiments through human stratum corneum and viable epidermis membranes. The self-assembled multiple emulsions allowed a more gradual percutaneous permeation (a zero-order permeation rate) than the two-step ones. The in vivo topical carrier properties of the two different multiple emulsions were evaluated on healthy human volunteers by using the spectrophotometry of reflectance, an in vivo non invasive method. These multiple emulsion systems were also compared with conventional emulsion formulations. Our findings demonstrated that the multiple emulsions obtained by self-assembling were able to provide a more sustained drug delivery into the skin and hence a longer therapeutic action than two-step multiple emulsions and conventional emulsion formulations. Finally, our findings showed that the supramolecular micro-assembly of multiple emulsions was able to influence not only the biopharmaceutical characteristics but also the potential in vivo therapeutic response.

Antimicrobial and Antioxidant Properties of Satureja Montana L. and S. Subspicata Vis. (Lamiaceae) by Dario Kremer, Iztok Jože Košir, Marijana Zovko Kon|i|, Andreja |erenak, Tanja Poto|nik, Siniša Sre|ec, Marko Randi|, Ivan Kosalec (1623-1633).
Satureja montana L. and S. subspicata Vis. (Lamiaceae) are used for centuries in traditional medicine of Balcanic people in the healing of the lymphatic nodule and respiratory system inflammation. In this paper the amount of total phenols and flavonoids (analyzed by UV/Vis spectrophotometry), phenolic compounds profile (analyzed by HPLC), antimicrobial and antioxidant activities were studied in samples collected in seven per species populations of S. montana and S. subspicata in Croatia. Eight phenolic compounds (rutin, quercetin, caffeic, p-coumaric, ellagic, protocatehuic, rosmarinic, and syringic acid) were identified and quantified using HPLC in methanolic and ethanolic extracts. Results showed that both species contained polyphenolics and other antioxidant compounds with chelating and radical-scavenging properties. The extracts prepared from both species showed broad spectrum of antimicrobial activity on in vitro tested microbial species (Staphylococcus aureus, Escherichia coli, Candida albicans, C. dubliniensis, C. krusei, C. glabrata, C. parapsilosis, and Microsporum gypseum).

Phosphonate Emerging Zinc Binding Group in Matrix Metalloproteinase Inhibitors by Cristina Campestre, Mariangela Agamennone, Marilena Tauro, Paolo Tortorella (1634-1644).
Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases, capable to degrade the extracellular matrix (ECM) in physiologic conditions. Because of their overexpression and pivotal role in many pathological events, they have been proposed as a therapeutic and prognostic target for a number of diseases. Selectivity among MMPs is essential for realizing the clinical potential of inhibitors. The design of MMP inhibitors (MMPIs) has largely focused on development of various compounds containing a zinc binding group (ZBG) in their structure, with hydroxamate being the most potent one. Due to the high degree of homology in the catalytic domain of all the MMPs, the specificity and selectivity of first generation hydroxamate MMPIs were minimal, with several off-target effects and binding to other metzincins. This review highlights the role of phosphonate as ZBG in the design and development of new MMPIs.

Docetaxel/2-Hydroxypropyl ? -Cyclodextrin Inclusion Complex Increases Docetaxel Solubility and Release from a Nanochannel Drug Delivery System by Silvia Ferrati, Eugenia Nicolov, Shyam Bansal, Sharath Hosali, Melissa Landis, Alessandro Grattoni (1645-1649).
Breast cancer remains the second leading cause of cancer deaths for women in the U.S. The need for new and alternative strategies to treat this cancer is imperative. Here we show the optimization of our nanochannel delivery system (nDS) for constant and sustained delivery of docetaxel (DTX) for thetreatment of triple negative breast cancer. DTX is a highly hydrophobic drug, making it difficult to reach the therapeutic levels when released in aqueous solutions from our implantable delivery system. To overcome this challenge and test the release of DTX from nDS, we prepared DTX/2-hydroxypropyl ?-cyclodextrin (DTX/HPCD) inclusion complexes in different molar ratios. The 1:10 DTX/HPCD complex achieved 5 times higher solubility than the 1:2 complex and 3 times higher in vitro release of DTX than with free DTX. When released in SCID/Beige mice from nanochannel system, the DTX/HPCD complex showed reduced tumor growth, comparable to the standard bolus injections of DTX, indicating that the structural stability and biological activity of DTX were retained in the complex, after its diffusion through the nanochannel system.

Inulin Derivatives Obtained Via Enhanced Microwave Synthesis for Nucleic Acid Based Drug Delivery by Carla Sardo, Emanuela Fabiola Craparo, Calogero Fiorica, Gaetano Giammona, Gennara Cavallaro (1650-1659).
A new class of therapeutic agents with a high potential for the treatment of different socially relevant human diseases is represented by Nucleic Acid Based Drugs (NABD), including small interfering RNAs (siRNA), decoy oligodeoxynucleotides (decoy ODN) and antisense oligonucleotides (ASOs). Although NABD can be engineered to be specifically directed against virtually any target, their susceptibility to nuclease degradation and the difficulty of delivery into target tissues severely limit their use in clinical practice and require the development of an appropriate nanostructured delivery system. For delivery of NABD, Inulin (Inu), a natural, water soluble and biocompatible polysaccharide, was derivatized by Spermine (Spm), a flexible molecule with four amine groups that, having pKa values in the range between 8-11, is mainly in the protonated form at pH 7.4. The synthesis of related copolymers (Inu-Spm) was performed by a two step reaction, using a method termed Enhanced Microwave Synthesis (EMS) which has the advantage, compared to conventional microwave reaction, that high amount of energy can be applied to the reaction system, by administering microwave irradiation and simultaneously controlling the temperature in the reaction vessel with cooled air. The synthesized inulin derivatives were characterized by FT-IR spectra and 1H-NMR. INU-Spm derivatives with a degree of derivatization of about 14 % mol/mol were obtained. These polycations were tested to evaluate their ability to form non covalent complexes with genetic material (polyplexes). Agarose gel retardation assays showed that the obtained copolymers are able to electrostatically interact with DNA duplex to form polyplexes at different c/p weight ratios. Moreover, light scattering studies, performed to analyze size and z-potential of polyplexes, evidenced that copolymers are able to interact with genetic material leading to the formation of nanoscaled systems. In addition, biocompatibility of polyplexes was demonstrated by performing cytotoxicity assays on a 16HBE cell line. Transfection studies, performed by using siRNA able to silence luciferase expression, demonstrate the efficiency of polyplexes to transfect the same cell line, with a reduction of luciferase expression to about 70%. These results encourage us to work with these copolymers to obtain an efficient and feasible inulin based NABD delivery system.

Antioxidant and antimicrobial properties of Veronica spicata L. (Plantaginaceae) by Valerija Dunki|, Ivan Kosalec, Iztok Joze Kosir, Tanja Potocnik, Andreja Cerenak, Marijana Zovko Koncic, Dubravka Vitali, Ivna Dragojevic Muller, Martina Kopricanec, Nada Bezic, Sinisa Srecec, Dario Kremer (1660-1670).
Tea made from Veronica spicata L. (syn. Pseudolysimachion spicatum (L.) Opiz, family Plantaginaceae) herb is used in traditional medicine as expectorant for cough and throat rinsing. To get insight into chemical compounds of V. spicata, the essential oil content (analysed by GC-FID and GC-MS), the content of phenolic compounds (analysed by HPLC), the content of macroelements and trace elements (analysed by ICP-AES), quantity of total phenols and total flavonoids (analysed by UV/Vis spectrophotometer), and antioxidant and antimicrobial properties were investigated. The main compounds of the essential oil were phytol (21.13%), heptacosane (10.22%) and pentacosane (8.91%). The most abundant investigated macroelement was K (8261 mg/kg) while Fe was the most represented element (32.49 mg/kg) among investigated micronutrients. Ten phenolic compounds (chrysin, rutin, quercitrin, quercitrin, and cichoric, ferulic, protocatehuic, rosmarinic, syringic and tannic acid) were identified and quantified. Additionally, V. spicata extract demonstrated notable radical-scavenging and chelating properties. The bacterial and fungal strains used in study were found to be susceptible toward methanolic and ethyl-acetate extracts with MIC values between 1.25 and 5.00 mg/mL using microdilution method. Aquose extracts were found to be antimicrobial inactive.

Safety of Nanoparticles in Medicine by Joy Wolfram, Motao Zhu, Yong Yang, Jianliang Shen, Emanuela Gentile, Donatella Paolino, Massimo Fresta, Guangjun Nie, Chunying Chen, Haifa Shen, Mauro Ferrari, Yuliang Zhao (1671-1681).
Nanomedicine involves the use of nanoparticles for therapeutic and diagnostic purposes. During the past two decades, a growing number of nanomedicines have received regulatory approval and many more show promise for future clinical translation. In this context, it is important to evaluate the safety of nanoparticles in order to achieve biocompatibility and desired activity. However, it is unwarranted to make generalized statements regarding the safety of nanoparticles, since the field of nanomedicine comprises a multitude of different manufactured nanoparticles made from various materials. Indeed, several nanotherapeutics that are currently approved, such as Doxil and Abraxane, exhibit fewer side effects than their small molecule counterparts, while other nanoparticles (e.g. metallic and carbon-based particles) tend to display toxicity. However, the hazardous nature of certain nanomedicines could be exploited for the ablation of diseased tissue, if selective targeting can be achieved. This review discusses the mechanisms for molecular, cellular, organ, and immune system toxicity, which can be observed with a subset of nanoparticles. Strategies for improving the safety of nanoparticles by surface modification and pretreatment with immunomodulators are also discussed. Additionally, important considerations for nanoparticle safety assessment are reviewed. In regards to clinical application, stricter regulations for the approval of nanomedicines might not be required. Rather, safety evaluation assays should be adjusted to be more appropriate for engineered nanoparticles.

Advanced Nanomedicines for the Treatment and Diagnosis of Myocardial Infarction and Heart Failure by Mónica P. A. Ferreira, Vimalkumar Balasubramanian, Jouni Hirvonen, Heikki Ruskoaho, Hélder A. Santos (1682-1697).
Nanotechnology has impacted tremendously the medical research with increasing importance in the development of new therapeutic approaches and applications. Among these applications, the use of nanocarriers has gained particular interest in order to achieve successful delivery of therapeutics and imaging agents for the treatment and diagnostics of different diseases, such as cancer, infections, diabetes, lung, brain and cardiovascular diseases. Heart failure (HF) is a complex clinical syndrome derived from multiple causes that arise from secondary to inherited or acquired abnormalities of cardiac structure and/or function. Myocardial infarction (MI), the major cause of HF, continues to be an increasing problem in terms of morbidity, mortality and healthcare costs worldwide. Currently, established pharmacological drugs have proven to be effective in reducing hypertrophy, remodeling of the myocardium, and in reducing morbidity and mortality in patients with HF. However, despite optimal treatment with existing drugs, the prognosis of HF is poor and also the possible deleterious effects of therapeutic agents must be considered when used at doses required for the desired therapeutic effect. Therefore, novel therapeutic strategies are urgently needed to prevent high morbidity and mortality associated with MI and HF. In this review, we will present recent developments in nanomedicine research envisaged to have an important impact on the treatment of cardiovascular diseases, particularly MI. In addition, we will discuss the use of different advanced modified nanosystems for molecular imaging and therapeutics of MI, presenting several in vitro and in vivo examples. Finally, we will conclude with an overview of the potential of nanomedicines in the future for the treatment of cardiovascular diseases.