Ultrastable shelled PFC nanobubbles: A platform for ultrasound-assisted diagnostics, and therapy.

Nanoscale echogenic bubbles (NBs), can be used as a theranostic platform for the localized delivery of encapsulated drugs. However, the generation of NBs is challenging, because they have lifetimes as short as milliseconds in solution. The aim of this work has been the optimization of a preparation method for the generation of stable NBs, characterized by measuring: a) acoustic efficiency, b) nano-size, to ensure passive tumour targeting, c) stability during storage and after injection and d) ability to entrap drugs. NBs are monodisperse and ultra-stable, their stability achieved by generation of an amphiphilic multilamellar shell able to efficiently retain the PFC gas. The NBs perform as good acoustic enhancers over a wide frequency range and out of resonant conditions, as tested in both in vitro and in vivo experiments, proving to be a potential platform for the production of versatile carriers to be used in ultrasound-assisted diagnostic, therapeutic and theranostic applications.

Practical instructions for using drugs in CT and MR cardiac imaging.

The progressive increase in numbers of noninvasive cardiac imaging examinations broadens the spectrum of knowledge radiologists are expected to acquire in the management of drugs during CT coronary angiography (CTCA) and cardiac MR (CMR) to improve image quality for optimal visualization and assessment of the coronary arteries and adequate MR functional analysis. Aim of this review is to provide an overview on different class of drugs (nitrate, beta-blockers, ivabradine, anxiolytic, adenosine, dobutamine, atropine, dipyridamole and regadenoson) that can be used in CTCA and CMR, illustrating their main indications, contraindications, efficacy, mechanism of action, metabolism, safety, side effects or complications, and providing advices in their use.

Hyaluronic Acid Derivative Effect on Niosomal Coating and Interaction with Cellular Mimetic Membranes.

Hyaluronic acid (HA) is one of the most used biopolymers in the development of drug delivery systems, due to its biocompatibility, biodegradability, non-immunogenicity and intrinsic-targeting properties. HA specifically binds to CD44; this property combined to the EPR effect could provide an option for reinforced active tumor targeting by nanocarriers, improving drug uptake by the cancer cells via the HA-CD44 receptor-mediated endocytosis pathway. Moreover, HA can be easily chemically modified to tailor its physico-chemical properties in view of specific applications. The derivatization with cholesterol confers to HA an amphiphilic character, and then the ability of anchoring to niosomes. HA-Chol was then used to coat Span® or Tween® niosomes providing them with an intrinsic targeting shell. The nanocarrier physico-chemical properties were analyzed in terms of hydrodynamic diameter, ζ-potential, and bilayer structural features to evaluate the difference between naked and HA-coated niosomes. Niosomes stability was evaluated over time and in bovine serum. Moreover, interaction properties of HA-coated nanovesicles with model membranes, namely liposomes, were studied, to obtain insights on their interaction behavior with biological membranes in future experiments. The obtained coated systems showed good chemical physical features and represent a good opportunity to carry out active targeting strategies.

Pentamidine niosomes thwart S100B effects in human colon carcinoma biopsies favouring wtp53 rescue.

S100B protein bridges chronic mucosal inflammation and colorectal cancer given its ability to activate NF-kappaB transcription via RAGE signalling and sequestrate pro-apoptotic wtp53. Being an S100B inhibitor, pentamidine antagonizes S100B-wtp53 interaction, restoring wtp53-mediated pro-apoptotic control in cancer cells in several types of tumours. The expression of S100B, pro-inflammatory molecules and wtp53 protein was evaluated in human biopsies deriving from controls, ulcerative colitis and colon cancer patients at baseline (a) and (b) following S100B targeting with niosomal PENtamidine VEhiculation (PENVE), to maximize drug permeabilization in the tissue. Cultured biopsies underwent immunoblot, EMSA, ELISA and biochemical assays for S100B and related pro-inflammatory/pro-apoptotic proteins. Exogenous S100B (0.005-5 µmol/L) alone, or in the presence of PENVE (0.005-5 µmol/L), was tested in control biopsies while PENVE (5 µmol/L) was evaluated on control, peritumoral, ulcerative colitis and colon cancer biopsies. Our data show that S100B level progressively increases in control, peritumoral, ulcerative colitis and colon cancer enabling a pro-inflammatory/angiogenic and antiapoptotic environment, featured by iNOS, VEGF and IL-6 up-regulation and wtp53 and Bax inhibition. PENVE inhibited S100B activity, reducing its capability to activate RAGE/phosphor-p38 MAPK/NF-kappaB and favouring its disengagement with wtp53. PENVE blocks S100B activity and rescues wtp53 expression determining pro-apoptotic control in colon cancer, suggesting pentamidine as a potential anticancer drug.

CCTA in the diagnosis of coronary artery disease.

The world of cardiac imaging is proposing to physicians an ever-increasing spectrum of options and tools with the disadvantages of patients presently submitted to multiple, sequential, time-consuming, and costly diagnostic procedures and tests, sometimes with contradicting results. In the last two decades, the CCTA has evolved into a valuable diagnostic test in today's patient care, changing the official existing guidelines and clinical practice with a pivotal role to exclude significant CAD, in the referral of patients to the Cath-Lab, in the follow-up after coronary revascularization, and finally in the cardiovascular risk stratification.

[The nursing hospice care: Critical incidents in managing the relationship with patients and their families]. / L'assistenza infermieristica in hospice: incidenti critici nella gestione della relazione con pazienti e familiari.

INTRODUCTION: The hospice care requires nurses to set an empathic but also uninvolved relationship with both the dying and their families. This requirement results in a challenging emotional work. AIMS: Detecting relational difficulties in assisting terminal patients, the study presents the results of an analysis focused on the emotional work of nurses in hospice. METHOD: Twenty-seven nurses voluntarily participated in an interview, realized with the Interpretative Phenomenological Analysis and aimed to investigate the conflicting lived regarded as critical incidents. RESULTS: All nurses are subject to continual emotional work to dissolve the dissonance between how intimately experienced and the implicit rules of the professional role, which seems to require their continuous surface acting. CONCLUSIONS: The palliative care model attaches great importance to the management of the emotional dimension in the relationship with the terminally ill patient and his family. Our research shows that this area is particularly critical and requires a constant burden for nurses. We believe that the emotional work is to find specific moments aimed at elaborating the emotional overload, from which compassion fatigue and burnout may depend.

Neem oil nanoemulsions: characterisation and antioxidant activity.

The aim of the present work is to develop nanoemulsions (NEs), nanosized emulsions, manufactured for improving the delivery of active pharmaceutical ingredients. In particular, nanoemulsions composed of Neem seed oil, contain rich bioactive components, and Tween 20 as nonionic surfactant were prepared. A mean droplet size ranging from 10 to 100 nm was obtained by modulating the oil/surfactant ratio. Physicochemical characterisation was carried out evaluating size, ζ-potential, microviscosity, polarity and turbidity of the external shell and morphology, along with stability in simulated cerebrospinal fluid (CSF), activity of Neem oil alone and in NEs, HEp-2 cell interaction and cytotoxicity studies. This study confirms the formation of NEs by Tween 20 and Neem oil at different weight ratios with small and homogenous dimensions. The antioxidant activity of Neem oil alone and in NEs was comparable, whereas its cytotoxicity was strongly reduced when loaded in NEs after interaction with HEp-2 cells.

pH-sensitive niosomes: Effects on cytotoxicity and on inflammation and pain in murine models.

pH-sensitive nonionic surfactant vesicles (niosomes) by polysorbate-20 (Tween-20) or polysorbate-20 derivatized by glycine (added as pH sensitive agent), were developed to deliver Ibuprofen (IBU) and Lidocaine (LID). For the physical-chemical characterization of vesicles (mean size, size distribution, zeta potential, vesicle morphology, bilayer properties and stability) dynamic light scattering (DLS), small angle X-ray scattering and fluorescence studies were performed. Potential cytotoxicity was evaluated on immortalized human keratinocyte cells (HaCaT) and on immortalized mouse fibroblasts Balb/3T3. In vivo antinociceptive activity (formalin test) and anti-inflammatory activity tests (paw edema induced by zymosan) in murine models were performed on drug-loaded niosomes. pH-sensitive niosomes were stable in the presence of 0 and 10% fetal bovine serum, non-cytotoxic and able to modify IBU or LID pharmacological activity in vivo. The synthesis of stimuli responsive surfactant, as an alternative to add pH-sensitive molecules to niosomes, could represent a promising delivery strategy for anesthetic and anti-inflammatory drugs.

pH-sensitive pHLIP® coated niosomes.

Nanomedicine is becoming very popular over conventional methods due to the ability to tune physico-chemical properties of nano vectors, which are used for encapsulation of therapeutic and diagnostic agents. However, the success of nanomedicine primarily relies on how specifically and efficiently nanocarriers can target pathological sites to minimize undesirable side effects and enhance therapeutic efficacy. Here, we introduce a novel class of targeted nano drug delivery system, which can be used as an effective nano-theranostic for cancer. We formulated pH-sensitive niosomes (80-90 nm in diameter) using nonionic surfactants Span20 (43-45 mol%), cholesterol (50 mol%) and 5 mol% of pH (Low) insertion peptide (pHLIP) conjugated with DSPE lipids (DSPE-pHLIP) or hydrophobic fluorescent dye, pyrene, (Pyr-pHLIP). In coating of niosomes, pHLIP was used as an acidity sensitive targeting moiety. We have demonstrated that pHLIP coated niosomes sense the extracellular acidity of cancerous cells. Intravenous injection of fluorescently labeled (R18) pHLIP-coated niosomes into mice bearing tumors showed significant accumulation in tumors with minimal targeting of kidney, liver and muscles. Tumor-targeting niosomes coated with pHLIP exhibited 2-3 times higher tumor uptake compared to the non-targeted niosomes coated with PEG polymer. Long circulation time and uniform bio-distribution throughout the entire tumor make pHLIP-coated niosomes to be an attractive novel delivery system.

Niosomes as Drug Nanovectors: Multiscale pH-Dependent Structural Response.

The use of nanocarriers, which respond to different stimuli controlling their physicochemical properties and biological responsivness, shows a growing interest in pharmaceutical science. The stimuli are activated by targeting tissues and biological compartments, e.g., pH modification, temperature, redox condition, enzymatic activity, or can be physically applied, e.g., a magnetic field and ultrasound. pH modification represents the easiest method of passive targeting, which is actually used to accumulate nanocarriers in cells and tissues. The aim of this paper was to physicochemically characterize pH-sensitive niosomes using different experimental conditions and demonstrate the effect of surfactant composition on the supramolecular structure of niosomes. In this attempt, niosomes, made from commercial (Tween21) and synthetic surfactants (Tween20 derivatives), were physicochemically characterized by using different techniques, e.g., transmission electron microscopy, Raman spectroscopy, and small-angle X-ray scattering. The changes of niosome structure at different pHs depend on surfactants, which can affect the supramolecular structure of colloidal nanocarriers and their potential use both in vitro and in vivo. At pH 7.4, the shape and structure of niosomes have been maintained; however, niosomes show some differences in terms of bilayer thicknesses, water penetration, membrane coupling, and cholesterol dispersion. The acid pH (5.5) can increase the bilayer fluidity, and affect the cholesterol depletion. In fact, Tween21 niosomes form large vesicles with lower curvature radius at acid pH; while Tween20-derivative niosomes increase the intrachain mobility within a more interchain correlated membrane. These results demonstrate that the use of multiple physicochemical procedures provides more information about supramolecular structures of niosomes and improves the opportunity to deeply investigate the effect of stimuli responsiveness on the niosome structure.

Bioactive pH-sensitive nanoemulsion in melanoma cell lines.

Melanoma is an aggressive form of skin cancer with elevated propensity to metastasize. One of the major critical issues in the treatment of oncological patients is represented by the development of toxicity and resistance to the available therapies. Great progress has been made in the field of nanotechnologies to limit the unwanted effects of anti-cancer treatments. We explored the potential of creating oil-in-water nanoemulsions composed of oleic acid, as a bioactive carrier for lipophilic drug delivery. This bioactive nanoemulsion was loaded with Curcumin, a natural fluorescent lipophilic compound, used as a model drug to evaluate nanoemulsion capability to: i) encapsulate the lipophilic moiety; ii) interact with the specific cells, and iii) improve the efficacy of the loaded model drug compared to the free one. Therefore, we evaluated the physical-chemical features of Curcumin-loaded nanoemulsions, confirming their pH sensibility and their stability over time. Moreover, the nanoemulsions were able to preserve the loaded Curcumin by degradation/destabilization phenomena. Finally, we verified some of the biological functions of Curcumin delivered by nanoemulsions in the B16F10 melanoma cell line. We obtained evidence of the biological action of Curcumin, suggesting oleic-based nanoemulsions as an efficient nanocarrier for lipophilic drug delivery.

pH-sensitive niosomes for ATRA delivery: A promising approach to inhibit Pin1 in high-grade serous ovarian cancer.

The peptidyl-prolyl cis/trans isomerase Pin1 positively regulates numerous cancer-driving pathways, and it is overexpressed in several malignancies, including high-grade serous ovarian cancer (HGSOC). The findings that all-trans retinoic acid (ATRA) induces Pin1 degradation strongly support that ATRA treatment might be a promising approach for HGSOC targeted therapy. Nevertheless, repurposing ATRA into the clinics for the treatment of solid tumors remains an unmet need mainly due to the insurgence of resistance and its ineffective delivery. In the present study, niosomes have been employed for improving ATRA delivery in HGSOC cell lines. Characterization of niosomes including hydrodynamic diameter, ζ-potential, morphology, entrapment efficiency and stability over time and in culture media was performed. Furthermore, pH-sensitiveness and ATRA release profile were investigated to demonstrate the capability of these vesicles to release ATRA in a stimuli-responsive manner. Obtained results documented a nanometric and monodispersed samples with negative ζ-potential. ATRA was efficiently entrapped, and a substantial release was observed in the presence of acidic pH (pH 5.5). Finally, unloaded niosomes showed good biocompatibility while ATRA-loaded niosomes significantly increased ATRA Pin1 inhibitory activity, which was consistent with cell growth inhibition. Taken together, ATRA-loaded niosomes might represent an appealing therapeutic strategy for HGSOC therapy.

Gentamicin loaded niosomes against intracellular uropathogenic Escherichia coli strains.

Urinary tract infections (UTIs) are the most common bacterial infections and uropathogenic Escherichia coli (UPEC) is the main etiological agent of UTIs. UPEC can persist in bladder cells protected by immunological defenses and antibiotics and intracellular behavior leads to difficulty in eradicating the infection. The aim of this paper is to design, prepare and characterize surfactant-based nanocarriers (niosomes) able to entrap antimicrobial drug and potentially to delivery and release antibiotics into UPEC-infected cells. In order to validate the proposed drug delivery system, gentamicin, was chosen as "active model drug" due to its poor cellular penetration. The niosomes physical-chemical characterization was performed combining different techniques: Dynamic Light Scattering Fluorescence Spectroscopy, Transmission Electron Microscopy. Empty and loaded niosomes were characterized in terms of size, ζ-potential, bilayer features and stability. Moreover, Gentamicin entrapped amount was evaluated, and the release study was also carried out. In addition, the effect of empty and loaded niosomes was studied on the invasion ability of UPEC strains in T24 bladder cell monolayers by Gentamicin Protection Assay and Confocal Microscopy. The observed decrease in UPEC invasion rate leads us to hypothesize a release of antibiotic from niosomes inside the cells. The optimization of the proposed drug delivery system could represent a promising strategy to significatively enhance the internalization of antimicrobial drugs.

Magnetic resonance imaging for assessment of rectal cancer nodes after chemoradiotherapy: A single center experience.

BACKGROUND: Accurate nodal restaging is becoming clinically more important in patients with locally advanced rectal cancer (LARC) with the emergence of organ-preserving treatment after a good response to neoadjuvant chemoradiotherapy (nCRT). PURPOSE: To evaluate the accuracy of MRI in identifying negative N status (ypN0 patients) in LARC after nCRT. MATERIAL AND METHODS: 191 patients with LARC underwent MRI before and 6-8 weeks after nCRT and subsequent total mesorectal excision. Short-axis diameter of mesorectal lymph nodes was evaluated on the high resolution T2-weighted images to compare MRI restaging with histopathology.. RESULTS: 146 and 45 patients had a negative N status (ypN0) and positive N status (ypN + ), respectively. On restaging MRI, the 70 % reduction in size of the largest node was associated with an area under the curve (AUC) of 0.818 to predict ypN0 stage, with a sensitivity of 93.3 % and a negative predictive value (NPV) of 95.4 %. No nodes were observed in 38 pts (37 pts ypN0 and 1 patient ypN + ), with sensitivity and NPV of nodes disappearance for ypN0 stage of 93.3 % and 92.5 % respectively. A 2.2 mm cut-off in short-axis diameter was associated with an AUC of 0.83 for the prediction of ypN0 nodal stage, with sensitivity and NPV of 79,5% and 91.1 % respectively. CONCLUSION: A reduction in size of 70 % of the largest limph-node on MRI at rectal cancer restaging has high sensitivity and NPV for prediction of ypN0 stage after nCRT. The high NPV of node disappearance and of a ≤ 2.2 mm short-axis diameter is confirmed.

Interaction of pH-sensitive non-phospholipid liposomes with cellular mimetic membranes.

Surfactant nanocarriers have received considerable attention in the last several years as interesting alternative to classic liposomes. Different pH-sensitive vesicular colloidal carriers based on Tween 20 derivatives, obtained after functionalization of the head groups of the surfactant with natural, or simply modified, amino acids, were proposed as drug nanocarriers. Dynamic light scattering, Small Angle X-ray Scattering, Trasmission Electron Microscopy and fluorescence studies were used for the physico-chemical characterization of vesicles and mean size, size distribution, zeta potential, vesicle morphology and bilayer properties were evaluated. The pH-sensitivity and the stability of formulations, in absence and in presence of foetal bovine serum, were also evaluated. Moreover, the contact between surfactant vesicles and liposomes designed to model the cellular membrane was investigated by fluorescence studies to preliminary explore the potential interaction between vesicle and cell membranes. Experimental findings showed that physico-chemical and technological features of pH-sensitive vesicles were influenced by the composition of the carriers. Furthermore, proposed carriers are able to interact with mimetic cell membrane and it is reasonable to attribute the observed differences in interaction to the architectural/structural properties of Tween 20 derivatives. The findings reported in this investigation showed that a deep and extensive physico-chemical characterization of the carrier is a fundamental step, according to the evidence that the knowledge of nanocarrier properties is necessary to translate its potentiality to in vitro/in vivo applications.

Liposomal chemotherapeutics.

Currently, six liposomal chemotherapeutics have received clinical approval and many more are in clinical trials or undergoing preclinical evaluation. Liposomes exhibit low toxicity and improve the biopharmaceutical features and therapeutic index of drugs, thereby increasing efficacy and reducing side effects. In this review we discuss the advantages of using liposomes for the delivery of chemotherapeutics. Gemcitabine and paclitaxel have been chosen as examples to illustrate how the performance of a metabolically unstable or poorly water-soluble drug can be greatly improved by liposomal incorporation. We look at the beneficial effects of liposomes in a variety of solid and blood-borne tumors, including thyroid cancer, pancreatic cancer, breast cancer and multiple myeloma.

Nanomedicines and nanocarriers in clinical trials: surfing through regulatory requirements and physico-chemical critical quality attributes.

Elucidation of physical-chemical characteristics of investigational medicinal products should be established with suitable methodology. Characterization of nanomedicines and nanocarriers in clinical trials may require the definition of additional specific properties depending on the nature of the nanostructures or nanomaterials composing the investigational medicinal product. The availability of regulatory requirements and guidelines is investigated focusing on critical quality attributes for nanomedicines and nanocarriers, mapping them in a clinical trial setting. Current regulatory challenges and issues are highlighted. The increasing complexity of nanostructures, the innovative connotation of applied nanotechnology, and the lack in capillarity or misalignment of relevant guidelines and terminology may lead to a potential not standardized approach in the characterization of nanomedicines and nanocarriers in clinical trials and delays in the approval process. Further efforts and a proactive approach from a regulatory standpoint would be desirable to surf the wave of innovation that impact nanomedicines and nanocarriers in clinical trials, in order to support clinical drug development capitalizing on technological advances and still ensuring a strong regulatory framework.

Mucoadhesive Rifampicin-Liposomes for the Treatment of Pulmonary Infection by Mycobacterium abscessus: Chitosan or ε-Poly-L-Lysine Decoration.

Mycobacterium abscessus (Mabs) is a dangerous non-tubercular mycobacterium responsible for severe pulmonary infections in immunologically vulnerable patients, due to its wide resistance to many different antibiotics which make its therapeutic management extremely difficult. Drug nanocarriers as liposomes may represent a promising delivery strategy against pulmonary Mabs infection, due to the possibility to be aerosolically administrated and to tune their properties in order to increase nebulization resistance and retainment of encapsulated drug. In fact, liposome surface can be modified by decoration with mucoadhesive polymers to enhance its stability, mucus penetration and prolong its residence time in the lung. The aim of this work is to employ Chitosan or ε-poly-L-lysine decoration for improving the properties of a novel liposomes composed by hydrogenated phosphatidyl-choline from soybean (HSPC) and anionic 1,2-Dipalmitoyl-sn-glycero-3-phosphorylglycerol sodium salt (DPPG) able to entrap Rifampicin. A deep physicochemical characterization of polymer-decorated liposomes shows that both polymers improve mucoadhesion without affecting liposome features and Rifampicin entrapment efficiency. Therapeutic activity on Mabs-infected macrophages demonstrates an effective antibacterial effect of ε-poly-L-lysine liposomes with respect to chitosan-decorated ones. Altogether, these results suggest a possible use of ε-PLL liposomes to improve antibiotic delivery in the lung.

Critical Analysis and Quality Assessment of Nanomedicines and Nanocarriers in Clinical Trials: Three Years of Activity at the Clinical Trials Office.

Investigational medicinal products submitted over the course of 3 years and authorized at the Clinical Trials Office of the Italian Medicines Agency as part of a request for authorization of clinical trials were scrutinized to identify those encompassing nanomedicines. The quality assessment reports performed on the documentation submitted were analyzed, classifying and discussing the most frequently detected issues. The identification of nanomedicines retrieved and the information on their quality profiles are shared to increase the transparency and availability of information, providing feedback that can support sponsors in optimizing the quality part of the documentation and of the information submitted. Results confirm that nanomedicines tested as investigational medicinal products in clinical trials are developed and authorized in agreement with the highest standards of quality, meeting safety profiles according to the strong regulatory requirements in the European Union. Some key points are highlighted and indicate that the regulatory approach to innovation in a clinical trial setting could potentially be renewed to ride the wave of innovation, particularly in the nanotechnology field, capitalizing on lessons learned and still ensuring a strong and effective framework.

Nano-Based Drug Delivery Systems of Potent MmpL3 Inhibitors for Tuberculosis Treatment.

Tuberculosis remains one of the world's deadliest infectious diseases, accounting for nearly 1.3 million deaths every year. Tuberculosis treatment is challenging because of the toxicity, decreased bioavailability at the target site of the conventional drugs and, most importantly, low adherence of patients; this leads to drug resistance. Here, we describe the development of suitable nanocarriers with specific physicochemical properties to efficiently deliver two potent antimycobacterial compounds. We prepared nanoemulsions and niosomes formulations and loaded them with two different MmpL3 inhibitors previously identified (NEs + BM635 and NIs + BM859). NEs + BM635 and NIs + BM859 were deeply characterized for their physicochemical properties and anti-mycobacterial activity. NEs + BM635 and NIs + BM859 showed good hydrodynamic diameter, ζ-Potential, PDI, drug-entrapment efficiency, polarity, and microviscosity and stability. Even though both formulations proved to perform well, only NIs + BM859 showed potent antimycobacterial activity against M. tuberculosis (MIC = 0.6 µM) compared to that of the free compound. This is most probably caused by the fact that BM635, being highly hydrophobic, encounters maximum hindrance in diffusion, whereas BM859, characterized by high solubility in aqueous medium (152 µM), diffuses more easily. The niosomal formulation described in this work may be a useful therapeutic tool for tuberculosis treatment, and further studies will follow to characterize the in vivo behavior of the formulation.