Lipid nanoparticles for local delivery of mRNA to the respiratory tract: Effect of PEG-lipid content and administration route

Design of inhalable mRNA therapeutics is promising because local administration in the respiratory tract is minimally invasive and induces a local response. However, several challenges related to administration via inhalation and respiratory tract barriers have so far prevented the progress of inhaled mRNA therapeutics. Here, we investigated factors of importance for lipid nanoparticle (LNP)-mediated delivery of mRNA to the respiratory tract. We hypothesized that: (i) the PEG-lipid content is important for providing colloidal stability during aerosolization and for mucosal delivery, (ii) the PEG-lipid contentinfluences the expression of mRNA-encoded protein in the lungs, and (iii) the route of administration (nasal versus pulmonary) affects mRNA delivery in the lungs. In this study, we aimed to optimize the PEG-lipid content for mucosal delivery and to investigatethe effect of administration route on the kinetics of protein expression. Our results show that increasing the PEG-lipid content improves the colloidal stability during the aerosolization process, but has a negative impact on the transfection efficiencyin vitro. The kinetics of protein expressionin vivois dependent on the route of administration, and we found that pulmonaryadministration of mRNA-LNPs to mice results inmore durable protein expression than nasaladministration. These results demonstrate that the design of the delivery system and the route of administration are importantfor achieving high mRNA transfection efficiency in the respiratory tract.

Evolution of the structure of lipid nanoparticles for nucleic acid delivery: From in situ studies of formulation to colloidal stability

The development of lipid nanoparticle (LNP) based therapeutics for delivery of RNA has triggered the advance of new strategies for formulation, such as high throughput microfluidics for precise mixing of components into well-defined particles. In this study, we have characterised the structure of LNPs throughout the formulation process using in situ small angle x-ray scattering in the microfluidic chip, then by sampling in the subsequent dialysis process. The final formulation was investigated with small angle x-ray (SAXS) and neutron (SANS) scattering, dynamic light scattering (DLS) and cryo-TEM. The effect on structure was investigated for LNPs with a benchmark lipid composition and containing different cargos: calf thymus DNA (DNA) and two model mRNAs, polyadenylic acid (polyA) and polyuridylic acid (polyU). The LNP structure evolved during mixing in the microfluidic channel, however was only fully developed during the dialysis. The colloidal stability of the final formulation was affected by the type of incorporated nucleic acids (NAs) and decreased with the degree of base-pairing, as polyU induced extensive particle aggregation. The main NA LNP peak in the SAXS data for the final formulation were similar, with the repeat distance increasing from polyU Collapse

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MESH Headings

• Scattering, Small Angle
• Lipids/chemistry
• X-Ray Diffraction
• Nanoparticles/chemistry
• DNA
• RNA, Messenger
• RNA, Small Interfering/chemistry
• Liposomes

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Affiliation(s)

Jennifer Gilbert Division of Physical Chemistry, Department of Chemistry, Lund University, 221 00 Lund, Sweden; NanoLund, Lund University, Professorsgatan 1, 223 63 Lund, Sweden
Federica Sebastiani Division of Physical Chemistry, Department of Chemistry, Lund University, 221 00 Lund, Sweden; Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100 København Ø, Denmark
Marianna Yanez Arteta Advanced Drug Delivery, Pharmaceutical Sciences, R&D, AstraZeneca, 431 83, Gothenburg, Sweden
Ann Terry MAX IV Laboratory, Lund University, Fotongatan 2, 224 84 Lund, Sweden
Anna Fornell MAX IV Laboratory, Lund University, Fotongatan 2, 224 84 Lund, Sweden
Robert Russell National Deuteration Facility (NDF), Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, 2232 Sydney, NSW, Australia
Najet Mahmoudi ISIS Neutron and Muon Source, Harwell Science and Innovation Campus, Didcot OX11 0QX, UK
Tommy Nylander Division of Physical Chemistry, Department of Chemistry, Lund University, 221 00 Lund, Sweden; NanoLund, Lund University, Professorsgatan 1, 223 63 Lund, Sweden; LINXS Institute of Advanced Neutron and X-Ray Science, Lund, Sweden; School of Chemical Engineering and Translational Nanobioscience Research Center, Sungkyunkwan University, Suwon, Republic of Korea.

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Mapping the landscape of immunonutrition and cancer research: a comprehensive bibliometric analysis on behalf of NutriOnc Research Group

The ongoing global health challenge of cancer is driving the pursuit of innovative avenues for prevention, treatment, and enhanced outcomes. The convergence of nutrition and immune modulation, known as immunonutrition, is ready to act as a catalyst for transformative change in cancer research and therapy. Our study employs a bibliometric analysis to uncover the evolving trends within immunonutrition and cancer research across the past 25 years. Bibliometric data, including authors, journals, affiliations, and countries, were analyzed using the Bibliometrix R package. Clustering algorithms were applied to keywords to identify thematic areas and their evolution. A total of 489 documents were analyzed, showing an annual growth rate of 8.7%, with a collaboration index of 5.41, highlighting comprehensive multidisciplinary involvement within this landscape. Core authors demonstrated sustained productivity, while occasional authors indicated widespread interest. The Medical University of Warsaw led in institutional contributions. Country-wise, Italy, France, and the USA emerged as forerunners in fostering research productivity. Key journals like 'Clinical Nutrition' served as beacons, emphasizing the multidimensional nature of this topic. The analysis highlighted growing research output and several collaborations, indicating the importance of immunoenriched nutrition in cancer treatment. The interplay of core authors and diversified engagement harmoniously accentuates the cross-disciplinary nature of this burgeoning field. International collaboration facilitated knowledge exchange. Prominent documents shaped the field, emphasizing the significance of nutritional interventions. Thematic clusters revealed varied focuses, including pharmaconutrients, surgical approaches, inflammation, and specific cancers. The expanding research output suggests further development, particularly in exploring immunoenriched nutrition's impact on cancer types and patient populations. The multidisciplinary nature and international collaborations enhance the field's progress. Gaps in research underscore the need for original studies and personalized approaches. This study guides future research, informing evidence-based nutritional interventions and advancing cancer care practices.

Dark peptide discs for the investigation of membrane proteins in supported lipid bilayers: the case of synaptobrevin 2 (VAMP2)

Supported lipid bilayers (SLBs) are commonly used as model systems mimicking biological membranes. Recently, we reported a new method to produce SLBs with incorporated membrane proteins, which is based on the application of peptide discs [Luchini et al., Analytical Chemistry, 2020, 92, 1081-1088]. Peptide discs are small discoidal particles composed of a lipid core and an outer belt of self-assembled 18A peptides. SLBs including membrane proteins can be formed by depositing the peptide discs on a solid support and subsequently removing the peptide by buffer rinsing. Here, we introduce a new variant of the 18A peptide, named dark peptide (d18A). d18A exhibits UV absorption at 214 nm, whereas the absorption at 280 nm is negligible. This improves sample preparation as it enables a direct quantification of the membrane protein concentration in the peptide discs by measuring UV absorption at 280 nm. We describe the application of the peptide discs prepared with d18A (dark peptide discs) to produce SLBs with a membrane protein, synaptobrevin 2 (VAMP2). The collected data showed the successful formation of SLBs with high surface coverage and incorporation of VAMP2 in a single orientation with the extramembrane domain exposed towards the bulk solvent. Compared to 18A, we found that d18A was more efficiently removed from the SLB. Our data confirmed the structural organisation of VAMP2 as including both α-helical and β-sheet secondary structure. We further verified the orientation of VAMP2 in the SLBs by characterising the binding of VAMP2 with α-synuclein. These results point at the produced SLBs as relevant membrane models for biophysical studies as well as nanostructured biomaterials.

Preterm birth and metabolic implications on later life: A narrative review focused on body composition

Preterm newborn infants are characterized by low body weight and lower fat mass at birth compared with full-term newborn neonates. Conversely, at term corrected age, body fat mass is more represented in preterm newborn infants, causing a predisposition to developing metabolic syndrome and cardiovascular diseases in later life with a different risk profile in men as compared with women. Postnatal growth is a complex change in anthropometric parameters and body composition. Both quantity and quality of growth are regulated by several factors such as fetal programming, early nutrition, and gut microbiota. Weight gain alone is not an optimal indicator of nutritional status as it does not accurately describe weight quality. The analysis of body composition represents a potentially useful tool to predict later metabolic and cardiovascular risk as it detects the quality of growth by differentiating between fat and lean mass. Longitudinal follow-up of preterm newborn infants could take advantage of body composition analysis in order to identify high-risk patients who apply early preventive strategies. This narrative review aimed to examine the state-of-the-art body composition among born preterm children, with a focus on those in the pre-school age group.

Screening of the binding affinity of serum proteins to lipid nanoparticles in a cell free environment

Lipid nanoparticles (LNPs) are promising drug and gene carriers. Upon intravenous administration, LNPs' experience different degree of cellular uptake depending on their formulation. Currently, in vitro and in vivo studies are the gold standard for assessing the fate of nano carriers once administered, but they are time consuming and expensive. In this work, we propose a time and cost-effective method to screen a wide range of LNP formulations and select the most promising candidates for in vitro and in vivo studies. Two different approaches were explored to investigate the binding affinity between LNPs and serum proteins using sensor functionalisation with either protein specific antibody or PEG specific antibody. The first approach allowed to identify the presence of a specific protein in the protein corona of lipid particles (reconstituted and native high-density lipoproteins (rHDL and HDL), and low-density lipoproteins LDL); while the second one provided a versatile platform for the immobilisation of pegylated-particles in order to follow the interaction with serum proteins and hence predict the composition of LNP protein corona. Sensing was done using Quartz Crystal Microbalance with Dissipation (QCM-D) but the approach is extendable to other surface sensing techniques such as Surface Plasmon Resonance (SPR) or ellipsometry.

ApoE and ApoE Nascent-Like HDL Particles at Model Cellular Membranes: Effect of Protein Isoform and Membrane Composition

Apolipoprotein E (ApoE), an important mediator of lipid transportation in plasma and the nervous system, plays a large role in diseases such as atherosclerosis and Alzheimer's. The major allele variants ApoE3 and ApoE4 differ only by one amino acid. However, this difference has major consequences for the physiological behaviour of each variant. In this paper, we follow (i) the initial interaction of lipid-free ApoE variants with model membranes as a function of lipid saturation, (ii) the formation of reconstituted High-Density Lipoprotein-like particles (rHDL) and their structural characterisation, and (iii) the rHDL ability to exchange lipids with model membranes made of saturated lipids in the presence and absence of cholesterol [1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) or 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine (POPC) with and without 20 mol% cholesterol]. Our neutron reflection results demonstrate that the protein variants interact differently with the model membranes, adopting different protein conformations. Moreover, the ApoE3 structure at the model membrane is sensitive to the level of lipid unsaturation. Small-angle neutron scattering shows that the ApoE containing lipid particles form elliptical disc-like structures, similar in shape but larger than nascent or discoidal HDL based on Apolipoprotein A1 (ApoA1). Neutron reflection shows that ApoE-rHDL do not remove cholesterol but rather exchange saturated lipids, as occurs in the brain. In contrast, ApoA1-containing particles remove and exchange lipids to a greater extent as occurs elsewhere in the body.

Apolipoprotein E Binding Drives Structural and Compositional Rearrangement of mRNA-Containing Lipid Nanoparticles

Emerging therapeutic treatments based on the production of proteins by delivering mRNA have become increasingly important in recent times. While lipid nanoparticles (LNPs) are approved vehicles for small interfering RNA delivery, there are still challenges to use this formulation for mRNA delivery. LNPs are typically a mixture of a cationic lipid, distearoylphosphatidylcholine (DSPC), cholesterol, and a PEG-lipid. The structural characterization of mRNA-containing LNPs (mRNA-LNPs) is crucial for a full understanding of the way in which they function, but this information alone is not enough to predict their fate upon entering the bloodstream. The biodistribution and cellular uptake of LNPs are affected by their surface composition as well as by the extracellular proteins present at the site of LNP administration, e.g., apolipoproteinE (ApoE). ApoE, being responsible for fat transport in the body, plays a key role in the LNP's plasma circulation time. In this work, we use small-angle neutron scattering, together with selective lipid, cholesterol, and solvent deuteration, to elucidate the structure of the LNP and the distribution of the lipid components in the absence and the presence of ApoE. While DSPC and cholesterol are found to be enriched at the surface of the LNPs in buffer, binding of ApoE induces a redistribution of the lipids at the shell and the core, which also impacts the LNP internal structure, causing release of mRNA. The rearrangement of LNP components upon ApoE incubation is discussed in terms of potential relevance to LNP endosomal escape.

Peptide discs as precursors of biologically relevant supported lipid bilayers

Supported lipid bilayers (SLBs) are commonly used to investigate the structure and dynamics of biological membranes. Vesicle fusion is a widely exploited method to produce SLBs. However, this process becomes less favoured when the vesicles contain complex lipid mixtures, e.g. natural lipid extracts. In these cases, it is often necessary to change experimental parameters, such as temperature, to unphysiological values to trigger the SLB formation. This may induce lipid degradation and is also not compatible with including membrane proteins or other biomolecules into the bilayers. Here, we show that the peptide discs, ~10 nm discoidal lipid bilayers stabilized in solution by a self-assembled 18A peptide belt, can be used as precursors for SLBs. The characterizations by means of neutron reflectometry and attenuated total reflectance-FTIR spectroscopy show that SLBs were successfully formed both from synthetic lipid mixtures (surface coverage 90-95%) and from natural lipid mixtures (surface coverage ~85%). Traces of 18A peptide (below 0.02 M ratio) left at the support surface after the bilayer formation do not affect the SLB structure. Altogether, we demonstrate that peptide disc formation of SLBs is much faster than the SLB formation by vesicle fusion and without the need of altering any experimental variable from physiologically relevant values.

Polymorphism of human telomeric quadruplexes with drugs: a multi-technique biophysical study

The human telomeric G-quadruplex structural motif of DNA has come to be known as a new and stimulating target for anticancer drug discovery. Small molecules that interact with G-quadruplex structures in a selective way have gained impressive interest in recent years as they may serve as potential therapeutic agents. Here, we show how circular dichroism, UV resonance Raman and small angle X-ray scattering spectroscopies can be effectively combined to provide insights into structural and molecular aspects of the interaction between human telomeric quadruplexes and ligands. This study focuses on the ability of berberine and palmatine to bind with human telomeric quadruplexes and provides analysis of the conformational landscape visited by the relevant complexes upon thermal unfolding. With increasing temperature, both free and bound G-quadruplexes undergo melting through a multi-state process, populating different intermediate states. Despite the structural similarity of the two ligands, valuable distinctive features characterising their interaction with the G-quadruplex emerged from our multi-technique approach.

Identification of Pistacia-associated flexivirus 1, a putative mycovirus of the family Gammaflexiviridae, in the mastic tree (Pistacia lentiscus) transcriptome

In this study, we identified the genome sequence of the novel virus Pistacia-associated flexivirus 1 (PAFV1), a putative member of the mycovirus family Gammaflexiviridae (the order Tymovirales), via analysis of a transcriptome dataset for the mastic tree (Pistacia lentiscus, the family Anacardiaceae). PAFV1 was predicted to have three open reading frames (ORFs): ORF1, encoding a replicase (REP) with RNA-dependent RNA polymerase activity; ORF2, a movement protein (MP); and ORF3, a hypothetical protein. The PAFV1 REP sequence showed high similarity to those of three known members of the family Gammaflexiviridae i.e., Entoleuca gammaflexivirus 1 (EnFV1), Entoleuca gammaflexivirus 2 (EnFV2), and Botrytis virus F (BVF). A genome contig of the fungus Monosporascus cannonballus also contained a sequence of an endogenous virus similar to that of PAFV1. Sequence comparison and phylogenetic analysis indicated that PAFV1, EnFV1, and the endogenous virus of M. cannonballus formed a distinct subgroup (apart from EnFV2 and BVF), and may be the founding members of a novel genus in the family Gammaflexiviridae. Notably, MP sequences of PAFV1/EnFV1 showed similarity to the MP sequences of the mycovirus group called tobamo-like mycoviruses (an unassigned taxon), implying that genomic recombination occurred between members of the family Gammaflexiviridae and tobamo-like mycoviruses. Since PAFV1 is phylogenetically related to mycoviruses, PAFV1 may also be a mycovirus that infected a fungus associated with the mastic tree sample, which is evidenced by the presence of fungal ribosomal RNA sequences in the mastic tree transcriptome. Thus, the PAFV1 genome sequence may be useful in elucidating the genome evolution of Gammaflexiviridae and tobamo-like mycoviruses. Keywords: Pistacia-associated flexivirus 1; Gammaflexiviridae; mycovirus, mastic tree.

Wrapping Up Hydrophobic Hydration: Locality Matters

Water, being the universal solvent, acts as a competing agent in fundamental processes, such as folding, aggregation or biomolecular recognition. A molecular understanding of hydrophobic hydration is of central importance to understanding the subtle free energy differences, which dictate function. Ab initio and classical molecular dynamics simulations yield two distinct hydration water populations in the hydration shell of solvated tert-butanol noted as "HB-wrap" and "HB-hydration2bulk". The experimentally observed hydration water spectrum can be dissected into two modes, centered at 164 and 195 cm-1. By comparison to the simulations, these two bands are attributed to the "HB-wrap" and "HB-hydration2bulk" populations, respectively. We derive a quantitative correlation between the population in each of these two local water coordination motifs and the temperature dependence of the solvation entropy. The crossover from entropy to enthalpy dominated solvation at elevated temperatures, as predicted by theory and observed experimentally, can be rationalized in terms of the distinct temperature stability and thermodynamic signatures of "HB-wrap" and "HB-hydration2bulk".

Design and use of model membranes to study biomolecular interactions using complementary surface-sensitive techniques

Cellular membranes are complex structures and simplified analogues in the form of model membranes or biomembranes are used as platforms to understand fundamental properties of the membrane itself as well as interactions with various biomolecules such as drugs, peptides and proteins. Model membranes at the air-liquid and solid-liquid interfaces can be studied using a range of complementary surface-sensitive techniques to give a detailed picture of both the structure and physicochemical properties of the membrane and its resulting interactions. In this review, we will present the main planar model membranes used in the field to date with a focus on monolayers at the air-liquid interface, supported lipid bilayers at the solid-liquid interface and advanced membrane models such as tethered and floating membranes. We will then briefly present the principles as well as the main type of information on molecular interactions at model membranes accessible using a Langmuir trough, quartz crystal microbalance with dissipation monitoring, ellipsometry, atomic force microscopy, Brewster angle microscopy, Infrared spectroscopy, and neutron and X-ray reflectometry. A consistent example for following biomolecular interactions at model membranes is used across many of the techniques in terms of the well-studied antimicrobial peptide Melittin. The overall objective is to establish an understanding of the information accessible from each technique, their respective advantages and limitations, and their complementarity.

A regional population-based hereditary breast cancer screening tool in Italy: First 5-year results

Background

Up to 10% of individuals with breast cancer (BC) belong to families with hereditary syndromes. The aim of this study was to develop an instrument to identify individuals/families at high‐hereditary risk for BC and offer dedicated surveillance programs according to different risks.

Methods

The instrument consisted of a primary questionnaire collecting history of BC and ovarian cancer (OC). This questionnaire was applied to women enrolled in the Emilia‐Romagna Breast Cancer Screening Program. General practitioners (GPs) and specialists could propose the same questionnaire too. Women with a score of ≥ 2, were invited to complete an oncogenetic counseling. According to the Tyrer‐Cuzick evaluation, women considered at high risk were invited to involve the most representative alive individual of the family affected with BC/OC for BRCA1/2 genetic testing.

Results

Since January 2012 and December 2016, 660 040 women were evaluated by the regional screening program, of which 22 289 (3.5%) were invited to the Spoke evaluation, but only 5615 accepted (25.2%). Totally, also considering women sent by GPs and specialists, 11 667 were assessed and 5554 were sent to the Hub evaluation. Finally, 2342 (42.8%) women fulfilled the criteria for genetic testing, and 544 (23.2%) resulted BRCA1/2 mutation carriers.

Conclusions

To our knowledge, this is the first regional population‐based multistep model that is aimed to identify individuals with BRCA1/2 mutations and to offer an intensive surveillance program for hereditary‐high risk women. This tool is feasible and effective, even if more efforts must be performed to increase the acceptance of multiple assessments by the study population.

Identification of a novel plant amalgavirus (Amalgavirus, Amalgaviridae) genome sequence in Cistus incanus

Amalgaviridae is a family of double-stranded, monosegmented RNA viruses that are associated with plants, fungi, microsporidians, and animals. A sequence contig derived from the transcriptome of a eudicot, Cistus incanus (the family Cistaceae; commonly known as hoary rockrose), was identified as the genome sequence of a novel plant RNA virus and named Cistus incanus RNA virus 1 (CiRV1). Sequence comparison and phylogenetic analysis indicated that CiRV1 is a novel species of the genus Amalgavirus in the family Amalgaviridae. The CiRV1 genome contig has two overlapping open reading frames (ORFs). ORF1 encodes a putative replication factory matrix-like protein, while ORF2 encodes a RNA-dependent RNA polymerase (RdRp) domain. An ORF1+2 fusion protein, which functions in viral RNA replication, is produced by a +1 programmed ribosomal frameshifting (PRF) mechanism. A +1 PRF motif UUU_CGU, which matches the conserved amalgavirus +1 PRF consensus sequence UUU_CGN, was found at the boundary of CiRV1 ORF1 and ORF2. Comparison of 25 amalgavirus ORF1+2 fusion proteins revealed that only three different positions within a 13-amino acid segment were recurrently used at the boundary, possibly being selected so as not to interfere with correct folding and function of the fusion protein. CiRV1 is the first virus found to be associated with the Cistus species and may be useful for studying amalgaviruses.

Novel Divavirus (the family Betaflexiviridae) and Mitovirus (the family Narnaviridae) species identified in basil (Ocimum basilicum)

Transcriptome data obtained from a plant sample often contain a large number of reads that are derived from associated RNA virus genomes that were co-isolated during RNA preparation. These virus-derived reads can be assembled into a novel plant RNA genome sequence. Here, a basil (Ocimum basilicum) transcriptome dataset was analyzed to identify two new RNA viruses, which were named Ocimum basilicum RNA virus 1 (ObRV1) and Ocimum basilicum RNA virus 2 (ObRV2). A phylogenetic analysis of the ObRV1 RNA-dependent RNA polymerase (RdRp) motif indicated that ObRV1 is a novel species of the genus Divavirus of the family Betaflexiviridae. ObRV1 is the fourth divavirus species to be identified. The ObRV2 RdRp motif showed sequence similarity to viruses of the genus Mitovirus of the family Narnaviridae, which infect fungal mitochondria. Although most of the known mitoviruses do not produce a functional RdRp using the plant mitochondrial genetic code, the ObRV2 encodes a full-length RdRp using both the fungal and plant mitochondrial genetic codes.

Effects of Aggregate Charge and Subphase Ionic Strength on the Properties of Spread Polyelectrolyte/Surfactant Films at the Air/Water Interface under Static and Dynamic Conditions

We demonstrate the ability to tune the formation of extended structures in films of poly(sodium styrenesulfonate)/dodecyltrimethylammonium bromide at the air/water interface through control over the charge/structure of aggregates as well as the ionic strength of the subphase. Our methodology to prepare loaded polyelectrolyte/surfactant films from self-assembled liquid crystalline aggregates exploits their fast dissociation and Marangoni spreading of material upon contact with an aqueous subphase. This process is proposed as a potential new route to prepare cheap biocompatible films for transfer applications. We show that films spread on water from swollen aggregates of low/negative charge have 1:1 charge binding and can be compressed only to a monolayer, beyond which material is lost to the bulk. For films spread on water from compact aggregates of positive charge, however, extended structures of the two components are created upon spreading or upon compression of the film beyond a monolayer. The application of ellipsometry, Brewster angle microscopy, and neutron reflectometry as well as measurements of surface pressure isotherms allow us to reason that formation of extended structures is activated by aggregates embedded in the film. The situation upon spreading on 0.1 M NaCl is different as there is a high concentration of small ions that stabilize loops of the polyelectrolyte upon film compression, yet extended structures of both components are only transient. Analogy of the controlled formation of extended structures in fluid monolayers is made to reservoir dynamics in lung surfactant. The work opens up the possibility to control such film dynamics in related systems through the rational design of particles in the future.

Use of metronomic chemotherapy in oncology: Results from a national Italian survey

Aims and background

Metronomic chemotherapy refers to the administration of low doses of cytotoxic agents over a prolonged period of time with no or only short drug-free intervals. It is designed to overcome acquired tumor resistance to chemotherapy and reduce neo-angiogenesis despite a lower toxicity than with standard chemotherapy. The role of metronomic chemotherapy remains controversial, and its optimal therapeutic use has not yet been defined.

Methods and study design

The present survey was designed as a short questionnaire and was sent to the medical oncologists registered with Medikey, a national database listing all the Italian oncology specialists linked with the Italian Council of Medical Oncology Hospital Consultants (Collegio Italiano Primari Oncologi Medici Ospedalieri, CIPOMO) and the Italian Association of Medical Oncology (Associazione Italiana di Oncologia Medica, AIOM). The questionnaire was completed on a voluntary basis and it was totally anonymous.

Results

The questionnaire was sent to 3,289 oncologists, and 191 (5.8%) actively participated in the survey. Seventy-two percent of responders declared that they had administered a regimen of metronomic chemotherapy at least once. Metronomic chemotherapy is commonly used in advanced breast cancer patients, and inmost cases it was prescribed after failure of at least two lines of treatment. Oral agents such as cyclophosphamide, capecitabine, methotrexate and vinorelbine were the most commonly prescribed drugs. Nearly 60% of responders was believed to have significantly less toxicity with metronomic chemotherapy than with standard chemotherapy.

Conclusions

The sample of oncologists who participated in the survey is small but it appears to be representative of the Italian medical oncology community. The answers to the questionnaire indicate a significant interest in metronomic chemotherapy, which is apparently widely prescribed. This is the first large national survey on the use of metronomic chemotherapy. Considering the results, larger research on metronomic chemotherapy is strongly warranted.

Simultaneous neutron reflectometry and infrared reflection absorption spectroscopy (IRRAS) study of mixed monolayer reactions at the air–water interface

Simultaneous neutron reflectometry and infrared spectroscopy can follow the oxidation of complex, realistic surfactant mixtures relevant for atmospheric chemistry.

Increased Incidence of Breast Cancer in Postmenopausal Women with High Body Mass Index at the Modena Screening Program

Purpose

We conducted a study to evaluate the relationship between body mass index (BMI) and the risk of breast cancer (BC) and outcome in a population of 14,684 women aged 55 to 69 years eligible to participate in the Mammography Screening Program (MSP) in the Province of Modena, Italy.

Methods

The study population was drawn from women who underwent mammography screening between 2004 and 2006 in the Province of Modena. Women were subdivided into obese, overweight, and normal-weight categories according to BMI and followed until July 31, 2010, to evaluate the BC incidence. The clinicopathological characteristics of BC were also evaluated in different groups of patients classified according to BMI. After BC diagnosis, patients were followed for a median period of 65 (range, 2–104) months. Second events (recurrences and second tumors) were recorded, and the 5-year event-free survival (EFS) was calculated.

Results

After a period of 73 months, 366 cases of BC were diagnosed. Compared with normal-weight women, obese women had a significantly higher incidence of BC (relative risk [RR], 1.32; p=0.040) (RR=1), larger tumors (27% of tumors were larger than T2 size), and more nodal involvement (38.5% of tumors were node-positive). Furthermore, a significantly higher rate of total events was seen in obese women compared with overweight and normal-weight patients, respectively (17.9% vs. 11.4% vs. 10.8%, p=0.032). The 5-year EFS was 89.0%, 89.0%, and 80.0% for normal-weight, overweight, and obese patients, respectively.

Conclusion

We observed a significantly higher risk of BC in obese women among those eligible to participate in the MSP in the Province of Modena. Finally, obese women had more second events and poorer EFS compared to nono bese women.

Spread Films of Human Serum Albumin at the Air-Water Interface: Optimization, Morphology, and Durability

It has been known for almost one hundred years that a lower surface tension can be achieved at the air-water interface by spreading protein from a concentrated solution than by adsorption from an equivalent total bulk concentration. Nevertheless, the factors that control this nonequilibrium process have not been fully understood. In the present work, we apply ellipsometry, neutron reflectometry, X-ray reflectometry, and Brewster angle microscopy to elaborate the surface loading of human serum albumin in terms of both the macroscopic film morphology and the spreading dynamics. We show that the dominant contribution to the surface loading mechanism is the Marangoni spreading of protein from the bulk of the droplets rather than the direct transfer of their surface films. The films can be spread on a dilute subphase if the concentration of the spreading solution is sufficient; if not, dissolution of the protein occurs, and only a textured adsorbed layer slowly forms. The morphology of the spread protein films comprises an extended network with regions of less textured material or gaps. Further, mechanical cycling of the surface area of the spread films anneals the network into a membrane that approach constant compressibility and has increased durability. Our work provides a new perspective on an old problem in colloid and interface science. The scope for optimization of the surface loading mechanism in a range of systems leading to its exploitation in deposition-based technologies in the future is discussed.

Twenty-years experience with de novo metastatic breast cancer

Although new treatments have been widely studied to improve the survival of patients with metastatic breast cancer (BC), prognosis continues to be poor with an average survival time no longer than 3 years. We carried on a population-based study with the purpose of evaluating the outcome of metastatic breast cancer in the province of Modena from 1990 to 2009. We examined the Modena Cancer Registry and evaluated the 5-year overall survival (OS) of women diagnosed with a de novo metastatic breast cancer between 1990 and 2009, defining 5 periods of 4 years each. After a median follow-up time of 29 months, the 5-year OS was 11% for years 1990-1993, 15% for years 1994-1997, 12% for years 1998-2001, 20% for years 2002-2005 and 29% for years 2006-2009 (p = 0.012). Overall, although no OS differences were noted in the first decade analyzed, a real advantage has been shown in the last two cohorts. In a multivariate analysis, the 5-year OS was significantly increased only for hormone receptor positive and HER2+ tumors, whereas chemotherapy treatments were not significant independent predictors of survival in "de novo" metastatic BC (p = 0.08). Our analysis confirms that the prognosis of de novo metastatic breast cancer has improved overtime, particularly in the last decade. Trastuzumab, LH-RH analogues and aromatase inhibitors have determined a significant clinical benefit and cost-effectiveness in metastatic breast cancer treatment.

Complementarity of neutron reflectometry and ellipsometry for the study of atmospheric reactions at the air–water interface

The combined application of neutron reflectometry and ellipsometry to determine the oxidation kinetics of organic monolayers at the air–water interface is described for the first time.

Terahertz Dynamics in Human Cells and Their Chromatin

The terahertz dynamics of human cells of the U937 line and their chromatin has been investigated by high-resolution inelastic X-ray scattering. To highlight its dynamical features in situ, nuclear DNA has been stained by uranyl-acetate salt. The general behavior of the collective dynamics of the whole cell is quite similar to that of bulk water, with a nearly wavevector-independent branch located at about 5 meV and a propagating mode with a linear trend corresponding to a speed of sound of 2900 ± 100 m/s. We provide the first experimental evidence for the existence of two branches also in the dispersion curves of chromatin. The high-energy mode displays an acoustic-like behavior with a sound velocity similar to unstained cells, but in this case the branch likely originates from the superposition of intramolecular DNA optic modes. A low-energy optic-like branch, distinctive of the chromatin moiety, is found at about 2.5 meV.

Ozonolysis of methyl oleate monolayers at the air–water interface: oxidation kinetics, reaction products and atmospheric implications

Ozonolysis of a methyl oleate monolayer results in its surprisingly rapid loss suggesting atmospheric lifetimes of organic material at the air–water interface of only ∼10 min.

High fasting blood glucose and obesity significantly and independently increase risk of breast cancer death in hormone receptor-positive disease

PURPOSE

We investigated the effect of fasting blood glucose and body mass index (BMI) at diagnosis on risk of breast cancer death for cases diagnosed in five Italian cancer registries in 2003-2005 and followed up to the end of 2008.

METHODS

For 1607 Italian women (≥15 years) with information on BMI or blood glucose or diabetes, we analysed the risk of breast cancer death in relation to glucose tertiles (≤84.0, 84.1-94.0, >94.0 mg/dl) plus diabetic and unspecified categories; BMI tertiles (≤23.4, 23.5-27.3, >27.3 kg/m(2), unspecified), stage (T1-3N0M0, T1-3N+M0 plus T4anyNM0, M1, unspecified), oestrogen (ER) and progesterone (PR) status (ER+PR+, ER-PR-, ER and PR unspecified, other), age, chemotherapy and endocrine therapy, using multiple regression models. Separate models for ER+PR+ and ER-PR- cases were also run.

RESULTS

Patients often had T1-3N0M0, ER+PR+ cancers and received chemotherapy or endocrine therapy; only 6% were M1 and 17% ER-PR-. Diabetic patients were older and had more often high BMI (>27 kg/m(2)), ER-PR-, M1 cancers than other patients. For ER+PR+ cases, with adjustment for other variables, breast cancer mortality was higher in women with high BMI than those with BMI 23.5-27.3 kg/m(2) (hazard ratio (HR)=2.9, 95% confidence interval (CI) 1.2-6.9). Breast cancer mortality was also higher in women with high (>94 mg/dl) blood glucose compared to those with glucose 84.1-94.0mg/dl (HR=2.6, 95% CI 1.2-5.7).

CONCLUSION

Our results provide evidence that in ER+PR+ patients, high blood glucose and high BMI are independently associated with increased risk of breast cancer death. Detection and correction of these factors in such patients may improve prognosis.

Acceptability and adherence in a chemoprevention trial among women at increased risk for breast cancer attending the Modena Familial Breast and Ovarian Cancer Center (Italy)

Chemoprevention for women at risk for breast cancer has been shown to be effective, but in actual practice, women's uptake of chemoprevention has been poor. We explored factors that influence acceptability, adherence, and dropout in the International Breast (Prevention) Intervention Study during our first 3 years of activity at the Modena Familial Breast and Ovarian Cancer Center. We evaluated socio-demographic characteristics, health status, adherence, and side effect intensity. Semi-structured interviews analyzed reasons for accepting/refusing/stopping the trial. A total of 471 postmenopausal women were invited to participate, of which 319 declined to participate (68%), 137 accepted to participate (29%), and 15 participants did not make a final decision (3%). Breast cancer-related worries and trust in our preventive and surveillance programs were the most frequent reasons for accepting. Side effect-related worry was the most frequent reason for refusing. General practitioners' and family members' opinions played an important role in the decision-making process. Adherence significantly decreased after a 12-month follow-up, but it remained unchanged after 24- and 36-month follow-ups. Mild/moderate side effects reported by women did not change after 12 months of treatment. Forty percent of women withdrew from the study due to complaints of side effects. We concluded that chemoprevention trials are difficult medical experiments and that the process of deciding about whether or not to participate is based mainly on beliefs and values. This study has important clinical implications. During counselling with prospective participants, it is important to emphasize the potential benefits and to promote an informed choice. How participants make decisions, their belief systems, and their perception of risk are all factors that should be investigated in future research.

Membrane thickness and the mechanism of action of the short peptaibol trichogin GA IV

Trichogin GA IV (GAIV) is an antimicrobial peptide of the peptaibol family, like the extensively studied alamethicin (Alm). GAIV acts by perturbing membrane permeability. Previous data have shown that pore formation is related to GAIV aggregation and insertion in the hydrophobic core of the membrane. This behavior is similar to that of Alm and in agreement with a barrel-stave mechanism, in which transmembrane oriented peptides aggregate to form a channel. However, while the 19-amino acid long Alm has a length comparable to the membrane thickness, GAIV comprises only 10 amino acids, and its helix is about half the normal bilayer thickness. Here, we report the results of neutron reflectivity measurements, showing that GAIV inserts in the hydrophobic region of the membrane, causing a significant thinning of the bilayer. Molecular dynamics simulations of GAIV/membrane systems were also performed. For these studies we developed a novel approach for constructing the initial configuration, by embedding the short peptide in the hydrophobic core of the bilayer. These calculations indicated that in the transmembrane orientation GAIV interacts strongly with the polar phospholipid headgroups, drawing them towards its N- and C-termini, inducing membrane thinning and becoming able to span the bilayer. Finally, vesicle leakage experiments demonstrated that GAIV activity is significantly higher with thinner membranes, becoming similar to that of Alm when the bilayer thickness is comparable to its size. Overall, these data indicate that a barrel-stave mechanism of pore formation might be possible for GAIV and for similarly short peptaibols despite their relatively small size.

Nuclear microsatellites for Pinus pinea (Pinaceae), a genetically depauperate tree, and their transferability to P. halepensis

PREMISE OF THE STUDY

Pinus pinea is one of the few widespread plant species that are also genetically depauperate. It is also an important commercial species with high market value seeds. A deeper knowledge of the existing population genetic variation was needed.

METHODS AND RESULTS

Twelve nuclear microsatellites were isolated from genomic and cDNA sequences and screened for variability in 729 individuals from 33 natural populations. Low level of genetic variability was confirmed with average expected heterozygosity of 0.11. Hardy-Weinberg equilibrium expectations were not met in only ∼10% of the possible locus/population combinations. All loci were in linkage equilibrium, and the frequency of null alleles was very low (≤1% in 332 out of 396 locus/population combinations). Nine out of the 12 microsatellites were successfully transferred to P. halepensis.

CONCLUSIONS

Despite low polymorphism, these new markers will be useful to resolve population structure and hold potential for seed origin identification and traceability.

Use of metronomic chemotherapy in oncology: results from a national Italian survey

AIMS AND BACKGROUND

Metronomic chemotherapy refers to the administration of low doses of cytotoxic agents over a prolonged period of time with no or only short drug-free intervals. It is designed to overcome acquired tumor resistance to chemotherapy and reduce neo-angiogenesis despite a lower toxicity than with standard chemotherapy. The role of metronomic chemotherapy remains controversial, and its optimal therapeutic use has not yet been defined.

METHODS AND STUDY DESIGN

The present survey was designed as a short questionnaire and was sent to the medical oncologists registered with Medikey, a national database listing all the Italian oncology specialists linked with the Italian Council of Medical Oncology Hospital Consultants (Collegio Italiano Primari Oncologi Medici Ospedalieri, CIPOMO) and the Italian Association of Medical Oncology (Associazione Italiana di Oncologia Medica, AIOM). The questionnaire was completed on a voluntary basis and it was totally anonymous.

RESULTS

The questionnaire was sent to 3,289 oncologists, and 191 (5.8%) actively participated in the survey. Seventy-two percent of responders declared that they had administered a regimen of metronomic chemotherapy at least once. Metronomic chemotherapy is commonly used in advanced breast cancer patients, and in most cases it was prescribed after failure of at least two lines of treatment. Oral agents such as cyclophosphamide, capecitabine, methotrexate and vinorelbine were the most commonly prescribed drugs. Nearly 60% of responders was believed to have significantly less toxicity with metronomic chemotherapy than with standard chemotherapy.

CONCLUSIONS

The sample of oncologists who participated in the survey is small but it appears to be representative of the Italian medical oncology community. The answers to the questionnaire indicate a significant interest in metronomic chemotherapy, which is apparently widely prescribed. This is the first large national survey on the use of metronomic chemotherapy. Considering the results, larger research on metronomic chemotherapy is strongly warranted.

Water dynamics as affected by interaction with biomolecules and change of thermodynamic state: a neutron scattering study

The dynamics of water as subtly perturbed by both the interaction with biomolecules and the variation of temperature and pressure has been investigated via neutron scattering spectroscopy. A measurement of inelastic neutron scattering devoted to the study of the coherent THz dynamics of water in a water-rich mixture with DNA (hydration level of 1 g DNA/15 g D(2)O) at room temperature is reported. The DNA hydration water coherent dynamics is characterised by the presence of collective modes, whose dispersion relations are similar to those observed in bulk water. These dispersion relations are well described by the interaction model developed in the case of bulk water, and the existence of a fast sound is experimentally demonstrated. The behaviour of the collective water dynamics was complemented by studying the single-particle dynamics of bulk water along the isotherm T = 298 K in the pressure range 0.1-350 MPa by means of incoherent scattering. This experiment is an attempt to simulate the change of the water molecular arrangement due to the interaction with DNA, by increasing the pressure as the presence of the biomolecule produces an increase in the density. An anomaly is found in the behaviour of the relaxation time derived from the quasi-elastic scattering signal, which can be related to the hypothetical second critical point in water. This anomaly and the transition from slow to fast sound take place in the same Q range, thus suggesting that the two phenomena could be related at some microscopic level.

Spatial genetic structure of Taxus baccata L. in the western Mediterranean Basin: past and present limits to gene movement over a broad geographic scale

English yew (Taxus baccata L., Taxaceae), a Tertiary relict, provides a seminal example of a widespread albeit locally endangered (often close to extinction) tree species. In order to gain detailed insights into the evolutionary dynamics of the species on a broad geographical scale, over 1000 trees from 91 populations of English yew in the western Mediterranean were analyzed using seven nuclear microsatellite markers. Our results revealed contrasting patterns of genetic structure at different spatial scales: genetic variation was highly structured at the local scale, while only a low proportion of the observed variation was attributed to regional differences. We also found a geographic gradient of decreasing diversity and increasing population divergence from northwest (central Europe and northern Iberian Peninsula) to southeast (Mediterranean Iberia and North Africa). The patterns revealed in this study probably reflect the combined effects of Quaternary climatic changes and recent impact of human activities, and potentially also more ancient events dating back to the Tertiary. Both climatic and anthropogenic factors seem to have conducted to a long history of population isolation, which may have contributed significantly to enhance population divergence through restricted gene flow and genetic drift.

Transcriptome changes in the cambial region of poplar (Populus alba L.) in response to water deficit

A transcriptome analysis of the Populus alba cambial region was performed with the aim of elucidating the gene network underlying the response to water deficit within the cambium and differentiating derivative cambial cells. Water stress was induced in 1-year-old P. alba plants by withholding water for 9 days. At that time, leaf predawn water potential fell to -0.8 MPa, resulting in a significant reduction in stomatal conductance, CO(2) assimilation and a consistent increment of stem shrinkage. These effects were almost fully reversed by re-hydration. The water deficit resulted in changes in gene expression that affected several functional categories, such as protein metabolism, cell wall metabolism, stress response, transporters and transcriptional regulation. The function of up- and down-regulated genes is discussed considering the physiological response of the plants to water deficit.

Is Cupressus sempervirens native in Italy? An answer from genetic and palaeobotanical data

This study represents the first large-scale analysis using nuclear molecular markers to assess genetic diversity and structure of Cupressus sempervirens L.. Genetic and fossil data were combined to infer the possible role of human activity and evolutionary history in shaping the diversity of cypress populations. We analysed 30 populations with six polymorphic nuclear microsatellite markers. Dramatic reductions in heterozygosity and allelic richness were observed from east to west across the species range. Structure analysis assigned individuals to two main groups separating central Mediterranean and eastern populations. The two main groups could be further divided into five subgroups which showed the following geographical distributions: Turkey with the Greek islands Rhodes and Samos, Greece (Crete), Southern Italy, Northern Italy, Tunisia with Central Italy. This pattern of genetic structure is also supported by SAMOVA and Barrier analyses. Palaeobotanical data indicated that Cupressus was present in Italy in the Pliocene, Pleistocene and Holocene. Furthermore, our molecular survey showed that Italian cypress populations experienced bottlenecks that resulted in reduced genetic diversity and allelic richness and greater genetic differentiation. Recent colonization or introduction may also have influenced levels of diversity detected in the Italian populations, as most individuals found in this range today have multilocus genotypes that are also present in the eastern range of the species. The data reveal a new interpretation of the history of cypress distribution characterized by ancient eastern populations (Turkey and Greek islands) and a mosaic of recently introduced trees and remnants of ancient, depauperate populations in the central Mediterranean range.

Isolation and characterization of polymorphic nuclear microsatellite loci in Pinus cembra L

We developed eight polymorphic nuclear microsatellite markers for the Swiss stone pine (Pinus cembra L.), of which seven may be amplified in a multiplex polymerase chain reaction. Allelic polymorphism across all loci and 40 individuals representing two populations in the Swiss Alps was high (mean = 7.6 alleles). No significant linkage disequlibrium was displayed between pairs of loci. Significant deviation from Hardy-Weinberg equilibrium was revealed at three loci in one population. Cross-amplification was achieved in two related species within the genus (P. sibirica and P. pumila). Thus, the markers may be useful for population genetic studies in these three pine species. They will be applied in ongoing projects on genetic diversity and patterns of gene flow in P. cembra.