Brain mapping across 16 autism mouse models reveals a spectrum of functional connectivity subtypes

Autism Spectrum Disorder (ASD) is characterized by substantial, yet highly heterogeneous abnormalities in functional brain connectivity. However, the origin and significance of this phenomenon remain unclear. To unravel ASD connectopathy and relate it to underlying etiological heterogeneity, we carried out a bi-center cross-etiological investigation of fMRI-based connectivity in the mouse, in which specific ASD-relevant mutations can be isolated and modeled minimizing environmental contributions. By performing brain-wide connectivity mapping across 16 mouse mutants, we show that different ASD-associated etiologies cause a broad spectrum of connectional abnormalities in which diverse, often diverging, connectivity signatures are recognizable. Despite this heterogeneity, the identified connectivity alterations could be classified into four subtypes characterized by discrete signatures of network dysfunction. Our findings show that etiological variability is a key determinant of connectivity heterogeneity in ASD, hence reconciling conflicting findings in clinical populations. The identification of etiologically-relevant connectivity subtypes could improve diagnostic label accuracy in the non-syndromic ASD population and paves the way for personalized treatment approaches.

2020 healthcare workers flu vaccination during covid-19: the experience of Udine University Hospital

Background

To prevent flu spread, Italian healthcare workers (HCWs) are annually recommended and given free flu vaccination. This measure of healthcare system protection resulted to be fundamental during COVID-19 pandemic to prevent staff shortage issue. Being the minimum coverage target set at 75%, we decided to evaluate vaccination adherence among HCWs at Udine University hospital.

Methods

The 2020 vaccination campaign started 4 weeks earlier than usual and was based on a multiple offer strategy including a daily-dedicated clinic, in-ward administrations along with wide vaccination agenda promotion within hospital. The prevalence and the characteristics of vaccinated HCWs were compared with the same 2019 data.

Results

During 2020, 1868 out of 3839 (48.7%) of HCWs were vaccinated, compared to 29.1% in 2019 (p < 0.0001). Doctors and residents were the most vaccinated categories in both years, being respectively 64.7% and 67.2% in 2020 vs 45.0% and 52.4% in 2019 (p < 0.0001). Midwives showed the best improvement in coverage passing from 44.4% to 20.4% (p = 0.0096). HCWs working in emergency areas and intensive care unit reached the highest adherence in 2020 (61.3%) and the best improvement compared to 2019 as well (37.9%; p < 0.0001).

Conclusions

Even if the target was not reached, strategies adopted for 2020 vaccination campaign significantly increased HCWs adherence. COVID-19 contribution in this achievement cannot be ruled out, possibly representing a strong reinforcing element for HCWs awareness towards infectious disease prevention.

Key messages

Despite the improvement in vaccination adherence, HCWs flu vaccination coverage still remains a concerning issue to be addressed. Increased flu shot adherence reached during COVID-19 pandemic should be not only a target to be maintained but even improved next year getting closer to herd immunity.

Flu vaccination coverage among healthcare workers: a comparison between 2018 and 2019 campaigns

Background

In Italy, recommended annual influenza vaccination is free to healthcare workers (HCWs) to prevent flu spread. No official data are available on HCWs' vaccination coverage (VC), which minimum target is set at 75%. Aim of this study is to compare 2019-20 and 2018-19 flu vaccination coverage in order to evaluate last year campaign effectiveness.

Methods

2019-20 flu vaccination campaign efforts at Udine Hospital (Italy) were improved with the aid of public health residents to tackle HCWs convenience concerns. From October 29th to December 5th 2019, dedicated areas and days were increased, informative course about influenza vaccination (efficacy, benefits and safety) toward HCWs were conducted. Data about HCWs getting their flu shot within the hospital were traced and analyzed, grouping different categories.

Results

During 2019-20 flu season, vaccinated HCWs were 29.1% (1,169/4,012), while they were 22.7% (955/4,203) in 2018-19 (p < 0.0001). The 2019-20 campaign resulted to be effective among doctors (45.0% vs 38.4%; p = 0.0132), residents (52.4% vs 40.7%; p = 0.0003) and nurses (24.1% vs 17.3%; p < 0.0001). The less compliant category was midwives, who maintained the worse vaccination coverage in both seasons (20.4% and 24.1%; p = 0.6555). Regarding other HCWs in 2019-20, 18.6% were vaccinated (in 2018-19 14.0%, p = 0.002).

Conclusions

A significant improvement in vaccination coverage during 2019-20 flu season was reached by the specific vaccination campaign for all categories except midwives. Despite this, the global vaccination coverage is still far from the desired target and more must be done to fill this gap. Evidence of HCWs categories for which this intervention was more effective, could be useful in planning next flu vaccination strategies.

Key messages

Continuous efforts made by public health professionals in promoting flu vaccination show their effect on healthcare workers flu shot adherence. A planned vaccination agenda and educative course about influenza infection and benefits of vaccination, seem to be good strategies to improve vaccination coverage.

Improving the accuracy of pancreatic cancer clinical staging by exploitation of nanoparticle-blood interactions: A pilot study

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) early diagnosis is  crucial  and new, cheap and user-friendly techniques for biomarker identification  are  needed. "Protein corona" (PC) is emerging a new bio-interface potentially useful in tumor early diagnosis. In a previous investigation, we showed that relevant differences between the  protein patterns of  PCs formed on lipid NPs after exposure to PDAC and non-cancer plasma  samples exist. To extend that research, We performed this pilot study to investigate the effect of PDAC tumor size and distant metastases on PC composition.

METHODS

Twenty PDACs were clinically staged according to the UICC TNM staging system 8 t h Edition. Collected plasma samples were let to interact with lipid NPs; resulting PCs were characterized by SDS-PAGE. To properly evaluate changes in the PC, the protein intensity profiles were reduced to four regions of molecular weight: < 25 kDa, 25-50 kDa, 50-120 kDa, > 120 kDa.  RESULTS: Data analysis allowed to distinguish T1-T2 cases from T3 and above all from metastatic ones (p < 0.05). Discrimination power was particularly due to a subset of plasma proteins with molecular  weight comprised between 25-50 kDa  and 50-120 kDa.

CONCLUSIONS

PC composition is critically influenced by tumor size and presence of distant metastases in PDAC. If our findings will be further confirmed, we envision that future developments of cheap and user-friendly PC-based tools will allow to improve the accuracy of PDAC clinical staging, identifying among resectable  PDACs with potentially better prognosis (i.e. T1 and T2) those at higher risk of occult distant metastases.

An apolipoprotein-enriched biomolecular corona switches the cellular uptake mechanism and trafficking pathway of lipid nanoparticles

Following exposure to biological milieus (e.g. after systemic administration), nanoparticles (NPs) get covered by an outer biomolecular corona (BC) that defines many of their biological outcomes, such as the elicited immune response, biodistribution, and targeting abilities. In spite of this, the role of BC in regulating the cellular uptake and the subcellular trafficking properties of NPs has remained elusive. Here, we tackle this issue by employing multicomponent (MC) lipid NPs, human plasma (HP) and HeLa cells as models for nanoformulations, biological fluids, and target cells, respectively. By conducting confocal fluorescence microscopy experiments and image correlation analyses, we quantitatively demonstrate that the BC promotes a neat switch of the cell entry mechanism and subsequent intracellular trafficking, from macropinocytosis to clathrin-dependent endocytosis. Nano-liquid chromatography tandem mass spectrometry identifies apolipoproteins as the most abundant components of the BC tested here. Interestingly, this class of proteins target the LDL receptors, which are overexpressed in clathrin-enriched membrane domains. Our results highlight the crucial role of BC as an intrinsic trigger of specific NP-cell interactions and biological responses and set the basis for a rational exploitation of the BC for targeted delivery.

REST-Dependent Presynaptic Homeostasis Induced by Chronic Neuronal Hyperactivity

Homeostatic plasticity is a regulatory feedback response in which either synaptic strength or intrinsic excitability can be adjusted up or down to offset sustained changes in neuronal activity. Although a growing number of evidences constantly provide new insights into these two apparently distinct homeostatic processes, a unified molecular model remains unknown. We recently demonstrated that REST is a transcriptional repressor critical for the downscaling of intrinsic excitability in cultured hippocampal neurons subjected to prolonged elevation of electrical activity. Here, we report that, in the same experimental system, REST also participates in synaptic homeostasis by reducing the strength of excitatory synapses by specifically acting at the presynaptic level. Indeed, chronic hyperactivity triggers a REST-dependent decrease of the size of synaptic vesicle pools through the transcriptional and translational repression of specific presynaptic REST target genes. Together with our previous report, the data identify REST as a fundamental molecular player for neuronal homeostasis able to downscale simultaneously both intrinsic excitability and presynaptic efficiency in response to elevated neuronal activity. This experimental evidence adds new insights to the complex activity-dependent transcriptional regulation of the homeostatic plasticity processes mediated by REST.

Clinically approved PEGylated nanoparticles are covered by a protein corona that boosts the uptake by cancer cells

Today, liposomes are an advanced technology of drug carriers with a dozen drugs in clinical practice and many more in clinical trials. A bottleneck associated with the clinical translation of liposomes has long been 'opsonization', i.e. the adsorption of plasma proteins at the liposome surface resulting in their rapid clearance from circulation. For decades, the most popular way to avoid opsonization has been grafting polyethylene glycol (PEG) onto the liposome surface. Recent studies have clarified that grafting PEG onto the liposome surface reduces, but does not completely prevent protein binding. In this work, we employed dynamic light scattering, zeta-potential analysis, one-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis (1D-SDS-PAGE), semi-quantitative densitometry and cell imaging to explore the bio-nano-interactions between human plasma (HP) and Onivyde, a PEGylated liposomal drug that has recently been approved by the Food and Drug Administration (FDA) for the treatment of metastatic pancreatic ductal adenocarcinoma (PDAC). To properly evaluate the role of PEGylation, an unPEGylated variant of Onivyde was used as a reference. Collectively, our findings suggest that: (i) although PEGylated, Onivyde is not "stealth" in HP; (ii) surface chemistry is more important than PEGylation in controlling the bio-nano-interactions between Onivyde and plasma components. Of note is that the PC was found to boost the cellular uptake of Onivyde in the pancreas ductal adenocarcinoma cell line (PANC-1) thus suggesting its prominent role in its indication for PDAC treatment. Relevant implications for drug delivery and drug design are discussed.

Biophysics and protein corona analysis of Janus cyclodextrin-DNA nanocomplexes. Efficient cellular transfection on cancer cells

The self-assembling processes underlining the capabilities of facially differentiated ("Janus") polycationic amphiphilic cyclodextrins (paCDs) as non-viral gene nanocarriers have been investigated by a pluridisciplinary approach. Three representative Janus paCDs bearing a common tetradecahexanoyl multitail domain at the secondary face and differing in the topology of the cluster of amino groups at the primary side were selected for this study. All of them compact pEGFP-C3 plasmid DNA and promote transfection in HeLa and MCF-7 cells, both in absence and in presence of human serum. The electrochemical and structural characteristics of the paCD-pDNA complexes (CDplexes) have been studied by using zeta potential, DLS, SAXS, and cryo-TEM. paCDs and pDNA, when assembled in CDplexes, render effective charges that are lower than the nominal ones. The CDplexes show a self-assembling pattern corresponding to multilamellar lyotropic liquid crystal phases, characterized by a lamellar stacking of bilayers of the CD-based vectors with anionic pDNA sandwiched among them. When exposed to human serum, either in the absence or in the presence of pDNA, the surface of the cationic CD-based vector becomes coated by a protein corona (PC) whose composition has been analyzed by nanoLC-MS/MS. Some of the CDplexes herein studied showed moderate-to-high transfection levels in HeLa and MCF-7 cancer cells combined with moderate-to-high cell viabilities, as determined by FACS and MTT reduction assays. The ensemble of data provides a detail picture of the paCD-pDNA-PC association processes and a rational base to exploit the protein corona for targeted gene delivery on future in vivo applications.

Biophysics and protein corona analysis of Janus cyclodextrin-DNA nanocomplexes. Efficient cellular transfection on cancer cells

The self-assembling processes underlining the capabilities of facially differentiated ("Janus") polycationic amphiphilic cyclodextrins (paCDs) as non-viral gene nanocarriers have been investigated by a pluridisciplinary approach. Three representative Janus paCDs bearing a common tetradecahexanoyl multitail domain at the secondary face and differing in the topology of the cluster of amino groups at the primary side were selected for this study. All of them compact pEGFP-C3 plasmid DNA and promote transfection in HeLa and MCF-7 cells, both in absence and in presence of human serum. The electrochemical and structural characteristics of the paCD-pDNA complexes (CDplexes) have been studied by using zeta potential, DLS, SAXS, and cryo-TEM. paCDs and pDNA, when assembled in CDplexes, render effective charges that are lower than the nominal ones. The CDplexes show a self-assembling pattern corresponding to multilamellar lyotropic liquid crystal phases, characterized by a lamellar stacking of bilayers of the CD-based vectors with anionic pDNA sandwiched among them. When exposed to human serum, either in the absence or in the presence of pDNA, the surface of the cationic CD-based vector becomes coated by a protein corona (PC) whose composition has been analyzed by nanoLC-MS/MS. Some of the CDplexes herein studied showed moderate-to-high transfection levels in HeLa and MCF-7 cancer cells combined with moderate-to-high cell viabilities, as determined by FACS and MTT reduction assays. The ensemble of data provides a detail picture of the paCD-pDNA-PC association processes and a rational base to exploit the protein corona for targeted gene delivery on future in vivo applications.

A protein corona-enabled blood test for early cancer detection

Pancreatic cancer is a very aggressive malignancy that is often diagnosed in the advanced stages, with the implication that long-term survivors are extremely rare. Thus, developing new methods for the early detection of pancreatic cancer is an urgent task for current research. To date, nanotechnology offers unprecedented opportunities for cancer therapeutics and diagnosis. The aim of this study is the development of a new pancreatic cancer diagnostic technology based on the exploitation of the nano-bio-interactions between nanoparticles and blood samples. In this study, blood samples from 20 pancreatic cancer patients and 5 patients without malignancy were allowed to interact with designed lipid nanoparticles, leading to the formation of a hard "protein corona" at the nanoparticle surface. After isolation, the protein patterns were characterized by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS PAGE). We found that the protein corona of pancreatic cancer patients was much more enriched than that of healthy individuals. Statistical analysis of SDS-PAGE results allowed us to discriminate between healthy and pancreatic cancer patients with a total discriminate correctness rate of 88%.

In vivo protein corona patterns of lipid nanoparticles

In vitro and in vivo biological identity of nanoparticles are substantially different.

Nanoparticles-cell association predicted by protein corona fingerprints

In a physiological environment (e.g., blood and interstitial fluids) nanoparticles (NPs) will bind proteins shaping a "protein corona" layer. The long-lived protein layer tightly bound to the NP surface is referred to as the hard corona (HC) and encodes information that controls NP bioactivity (e.g. cellular association, cellular signaling pathways, biodistribution, and toxicity). Decrypting this complex code has become a priority to predict the NP biological outcomes. Here, we use a library of 16 lipid NPs of varying size (Ø≈ 100-250 nm) and surface chemistry (unmodified and PEGylated) to investigate the relationships between NP physicochemical properties (nanoparticle size, aggregation state and surface charge), protein corona fingerprints (PCFs), and NP-cell association. We found out that none of the NPs' physicochemical properties alone was exclusively able to account for association with human cervical cancer cell line (HeLa). For the entire library of NPs, a total of 436 distinct serum proteins were detected. We developed a predictive-validation modeling that provides a means of assessing the relative significance of the identified corona proteins. Interestingly, a minor fraction of the HC, which consists of only 8 PCFs were identified as main promoters of NP association with HeLa cells. Remarkably, identified PCFs have several receptors with high level of expression on the plasma membrane of HeLa cells.

Exploitation of nanoparticle–protein corona for emerging therapeutic and diagnostic applications

Exposure of nanoparticles (NPs) to biological fluids (e.g., plasma, interstitial fluid, and cytoplasm) leads to the absorption of proteins on the NP surface, forming a protein corona (PC) that drastically influences the NP physicochemical properties.

The biomolecular corona of nanoparticles in circulating biological media

When nanoparticles come into contact with biological media, they are covered by a biomolecular 'corona', which confers a new identity to the particles. In all the studies reported so far nanoparticles are incubated with isolated plasma or serum that are used as a model for protein adsorption. Anyway, bodily fluids are dynamic in nature so the question arises on whether the incubation protocol, i.e. dynamic vs. static incubation, could affect the composition and structure of the biomolecular corona. Here we let multicomponent liposomes interact with fetal bovine serum (FBS) both statically and dynamically, i.e. in contact with circulating FBS (≈40 cm s(-1)). The structure and composition of the liposome-protein corona, as determined by dynamic light scattering, electrophoretic light scattering and liquid chromatography tandem mass spectrometry, were found to be dependent on the incubation protocol. Specifically, following dynamic exposure to FBS, multicomponent liposomes were less enriched in complement proteins and appreciably more enriched in apolipoproteins and acute phase proteins (e.g. alpha-1-antitrypsin and inter-alpha-trypsin inhibitor heavy chain H3) that are involved in relevant interactions between nanoparticles and living systems. Supported by our results, we speculate that efficient predictive modeling of nanoparticle behavior in vivo will require accurate knowledge of nanoparticle-specific protein fingerprints in circulating biological media.

Reduced SNAP-25 increases PSD-95 mobility and impairs spine morphogenesis

Impairment of synaptic function can lead to neuropsychiatric disorders collectively referred to as synaptopathies. The SNARE protein SNAP-25 is implicated in several brain pathologies and, indeed, brain areas of psychiatric patients often display reduced SNAP-25 expression. It has been recently found that acute downregulation of SNAP-25 in brain slices impairs long-term potentiation; however, the processes through which this occurs are still poorly defined. We show that in vivo acute downregulation of SNAP-25 in CA1 hippocampal region affects spine number. Consistently, hippocampal neurons from SNAP-25 heterozygous mice show reduced densities of dendritic spines and defective PSD-95 dynamics. Finally, we show that, in brain, SNAP-25 is part of a molecular complex including PSD-95 and p140Cap, with p140Cap being capable to bind to both SNAP-25 and PSD-95. These data demonstrate an unexpected role of SNAP-25 in controlling PSD-95 clustering and open the possibility that genetic reductions of the protein levels - as occurring in schizophrenia - may contribute to the pathology through an effect on postsynaptic function and plasticity.

Lipid composition: a “key factor” for the rational manipulation of the liposome–protein corona by liposome design

When liposomes are exposed to biological fluids, a dynamic protein coating immediately covers them forming a ‘protein corona’. Those proteins can interact with receptors (over)expressed on the plasma membrane of target cells bringing the liposomes to their final destination.

Ultrasound well below the intensity threshold of cavitation can promote efficient uptake of small drug model molecules in fibroblast cells

Ultrasound (US) induced enhancement of plasma membrane permeability is a hugely promising tool for delivering exogenous vectors at the specific biological site in a safe and efficient way. In this respect, here we report effects of membrane permeability alteration on fibroblast-like cells undergoing very low-intensity of US. The change in permeability was pointed out in terms of high uptake efficiency of the fluoroprobe calcein, thus resembling internalization of small cell-impermeable model drugs, as measured by fluorescence microscopy and flow cytometry. Fluorescence evidences moreover suggests that the higher the time of exposure, the larger will be the size of molecules can be internalized. The uptake events were related to the cell viability and also with structural changes occurring at membrane level as revealed by infrared spectroscopy and preliminary membrane fluidity and atomic force microscopy (AFM) investigation. Thus, the question of whether the uptake of cell-impermeable molecules is consistent with the presence of disruptions on the cell membrane (sonopore formation) has been addressed. In this framework, our findings may constitute experimental evidence in support of sub-cavitation sonoporation models recently proposed, and they may also provide some hints towards the actual working condition of medical US dealing with the optimum risk to benefit therapeutic ratio.

Structural and permeability sensitivity of cells to low intensity ultrasound: Infrared and fluorescence evidence in vitro

This work is focused on the in vitro study of the effects induced by medical ultrasound (US) in murine fibroblast cells (NIH-3T3) at a low-intensity of exposure (spatial peak temporal average intensity Ita<0.1Wcm(-2)). Conventional 1MHz and 3MHz US devices of therapeutic relevance were employed with varying intensity and exposure time parameters. In this framework, upon cells exposure to US, structural changes at the molecular level were evaluated by infrared spectroscopy; alterations in plasma membrane permeability were monitored in terms of uptake efficiency of small cell-impermeable model drug molecules, as measured by fluorescence microscopy and flow cytometry. The results were related to the cell viability and combined with the statistical PCA analysis, confirming that NIH-3T3 cells are sensitive to therapeutic US, mainly at 1MHz, with time-dependent increases in both efficiency of uptake, recovery of wild-type membrane permeability, and the size of molecules entering 3T3. On the contrary, the exposures from US equipment at 3MHz show uptakes comparable with untreated samples.

A proteomics-based methodology to investigate the protein corona effect for targeted drug delivery

Here we introduce a proteomics methodology based on nanoliquid-chromatography tandem mass spectrometry (nanoLC/MS-MS) to investigate the “protein corona effect for targeted drug delivery”.

Mechanistic evaluation of the transfection barriers involved in lipid-mediated gene delivery: interplay between nanostructure and composition

Here we present a quantitative mechanism-based investigation aimed at comparing the cell uptake, intracellular trafficking, endosomal escape and final fate of lipoplexes and lipid-protamine/deoxyribonucleic acid (DNA) (LPD) nanoparticles (NPs) in living Chinese hamster ovary (CHO) cells. As a model, two lipid formulations were used for comparison. The first formulation is made of the cationic lipid 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) and the zwitterionic lipid dioleoylphosphocholine (DOPC), while the second mixture is made of the cationic 3β-[N-(N,N-dimethylaminoethane)-carbamoyl] cholesterol (DC-Chol) and the zwitterionic helper lipid dioleoylphosphatidylethanolamine (DOPE). Our findings indicate that lipoplexes are efficiently taken up through fluid-phase macropinocytosis, while a less efficient uptake of LPD NPs occurs through a combination of both macropinocytosis and clathrin-dependent pathways. Inside the cell, both lipoplexes and LPD NPs are actively transported towards the cell nucleus, as quantitatively addressed by spatio-temporal image correlation spectroscopy (STICS). For each lipid formulation, LPD NPs escape from endosomes more efficiently than lipoplexes. When cells were treated with DOTAP-DOPC-containing systems the majority of the DNA was trapped in the lysosome compartment, suggesting that extensive lysosomal degradation was the rate-limiting factors in DOTAP-DOPC-mediated transfection. On the other side, escape from endosomes is large for DC-Chol-DOPE-containing systems most likely due to DOPE and cholesterol-like molecules, which are able to destabilize the endosomal membrane. The lipid-dependent and structure-dependent enhancement of transfection activity suggests that DNA is delivered to the nucleus synergistically: the process requires both the membrane-fusogenic activity of the nanocarrier envelope and the employment of lipid species with intrinsic endosomal rupture ability.

Mechanistic understanding of gene delivery mediated by highly efficient multicomponent envelope-type nanoparticle systems

We packaged condensed DNA/protamine particles in multicomponent envelope-type nanoparticle systems (MENS) combining different molar fractions of the cationic lipids 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) and 3β-[N-(N,N-dimethylaminoethane)-carbamoyl] cholesterol (DC-Chol) and the zwitterionic lipids dioleoylphosphocholine (DOPC) and dioleoylphosphatidylethanolamine (DOPE). Dynamic light scattering (DLS) and microelectrophoresis allowed us to identify the cationic lipid/DNA charge ratio at which MENS are small sized and positively charged, while synchrotron small-angle X-ray scattering (SAXS) and atomic force microscopy (AFM) revealed that MENS are well-shaped DNA/protamine particles covered by a lipid monobilayer. Transfection efficiency (TE) experiments indicate that a nanoparticle formulation, termed MENS-3, was not cytotoxic and highly efficient to transfect Chinese hamster ovary (CHO) cells. To rationalize TE, we performed a quantitative investigation of cell uptake, intracellular trafficking, endosomal escape, and final fate by laser scanning confocal microscopy (LSCM). We found that fluid-phase macropinocytosis is the only endocytosis pathway used by MENS-3. Once taken up by the cell, complexes that are actively transported by microtubules frequently fuse with lysosomes, while purely diffusing systems do not. Indeed, spatiotemporal image correlation spectroscopy (STICS) clarified that MENS-3 mostly exploit diffusion to move in the cytosol of CHO cells, thus explaining the high TE levels observed. Also, MENS-3 exhibited a marked endosomal rupture ability resulting in extraordinary DNA release. The lipid-dependent and structure-dependent TE boost suggests that efficient transfection requires both the membrane-fusogenic activity of the nanocarrier envelope and the employment of lipid species with intrinsic endosomal rupture ability.

Non ionising radiation as a non chemical strategy in regenerative medicine: Ca(2+)-ICR "In Vitro" effect on neuronal differentiation and tumorigenicity modulation in NT2 cells

In regenerative medicine finding a new method for cell differentiation without pharmacological treatment or gene modification and minimal cell manipulation is a challenging goal. In this work we reported a neuronal induced differentiation and consequent reduction of tumorigenicity in NT2 human pluripotent embryonal carcinoma cells exposed to an extremely low frequency electromagnetic field (ELF-EMF), matching the cyclotron frequency corresponding to the charge/mass ratio of calcium ion (Ca(2+)-ICR). These cells, capable of differentiating into post-mitotic neurons following treatment with Retinoic Acid (RA), were placed in a solenoid and exposed for 5 weeks to Ca(2+)-ICR. The solenoid was installed in a μ-metal shielded room to avoid the effect of the geomagnetic field and obtained totally controlled and reproducible conditions. Contrast microscopy analysis reveled, in the NT2 exposed cells, an important change in shape and morphology with the outgrowth of neuritic-like structures together with a lower proliferation rate and metabolic activity alike those found in the RA treated cells. A significant up-regulation of early and late neuronal differentiation markers and a significant down-regulation of the transforming growth factor-α (TGF-α) and the fibroblast growth factor-4 (FGF-4) were also observed in the exposed cells. The decreased protein expression of the transforming gene Cripto-1 and the reduced capability of the exposed NT2 cells to form colonies in soft agar supported these last results. In conclusion, our findings demonstrate that the Ca(2+)-ICR frequency is able to induce differentiation and reduction of tumorigenicity in NT2 exposed cells suggesting a new potential therapeutic use in regenerative medicine.

Quantitative measurement of intracellular transport of nanocarriers by spatio-temporal image correlation spectroscopy

Spatio-temporal image correlation spectroscopy (STICS) is a powerful technique for assessing the nature of particle motion in complex systems although it has been rarely used to investigate the intracellular dynamics of nanocarriers so far. Here we introduce a method to characterize the mode of motion of nanocarriers and to quantify their transport parameters on different length scales from single-cell to subcellular level. Using this strategy we were able to study the mechanisms responsible for the intracellular transport of DOTAP-DOPC/DNA and DC-Chol-DOPE/DNA lipoplexes in CHO-K1 live cells. Measurement of both diffusion coefficients and velocity vectors (magnitude and direction) averaged over regions of the cell revealed the presence of distinct modes of motion. Lipoplexes diffused slowly on the cell surface (diffusion coefficient, D ≈ 0.003 µm²/s). In the cytosol, the lipoplexes' motion was characterized by active transport with average velocity ν ≈ 0.03 µm/s and random motion. The method permitted us to generate intracellular transport map showing several regions of concerted motion of lipoplexes.

Ultrasound-mediated structural changes in cells revealed by FTIR spectroscopy: a contribution to the optimization of gene and drug delivery

Ultrasound effects on biological samples are gaining a growing interest concerning in particular, the intracellular delivery of drugs and genes in a safe and in a efficient way. Future progress in this field will require a better understanding of how ultrasound and acoustic cavitation affect the biological system properties. The morphological changes of cells due to ultrasound (US) exposure have been extensively studied, while little attention has been given to the cells structural changes. We have exposed two different cell lines to 1 MHz frequency ultrasound currently used in therapy, Jurkat T-lymphocytes and NIH-3T3 fibroblasts, both employed as models respectively in the apoptosis and in the gene therapy studies. The Fourier Transform Infrared (FTIR) Spectroscopy was used as probe to reveal the structural changes in particular molecular groups belonging to the main biological systems. The genotoxic damage of cells exposed to ultrasound was ascertained by the Cytokinesis-Block Micronucleus (CBMN) assay. The FTIR spectroscopy results, combined with multivariate statistical analysis, regarding all cellular components (lipids, proteins, nucleic acids) of the two cell lines, show that Jurkat cells are more sensitive to therapeutic ultrasound in the lipid and protein regions, whereas the NIH-3T3 cells are more sensitive in the nucleic acids region; a meaningful genotoxic effect is present in both cell lines only for long sonication times while in the Jurkat cells also a significant cytotoxic effect is revealed for long times of exposure to ultrasound.

Role of temperature-independent lipoplex-cell membrane interactions in the efficiency boost of multicomponent lipoplexes

Multicomponent lipoplexes have recently emerged as especially promising transfection candidates, as they are from 10 to 100 times more efficient than binary complexes usually employed for gene delivery purposes. Previously, we investigated a number of chemical-physical properties of DNA-lipid complexes that were proposed to affect transfection efficiency (TE) of lipoplexes, such as nanoscale structure, size, surface potential, DNA-protection ability and DNA release from complexes upon interaction with cellular lipids. Although some minor differences between multicomponent and binary lipoplexes were found, they did not correlate clearly with efficiency. Instead, here we show that a marked difference between the cell internalization mechanism of binary and multicomponent lipoplexes does exist. Multicomponent lipoplexes significantly transfect cells at 4 °C, when endocytosis does not take place suggesting that they can enter cells via a temperature-independent mechanism. Confocal fluorescence microscopy experiments showed the existence of a correlation between endosomal escape and TE. Multicomponent lipoplexes exhibited a distinctive ability of endosomal escape and release DNA into the nucleus, whereas, poorly efficient binary lipoplexes exhibited minor, if any, endosomal rupture ability and remained confined in perinuclear late endosomes. Stopped-flow mixing measurements showed that the fusion rates of multicomponent cationic liposomes with anionic vesicles, used as model systems of cell membranes, were definitely shorter than those of binary liposomes. As either lipoplex uptake and endosomal escape involve fusion between lipoplex and cellular membranes, we suggest that a mechanism of lipoplex-cellular membrane interaction, driven by lipid mixing between cationic and anionic cellular lipids, does explain the TE boost of multicomponent lipoplexes.

Differentiation of human adult cardiac stem cells exposed to extremely low-frequency electromagnetic fields

AIMS

Modulation of cardiac stem cell (CSC) differentiation with minimal manipulation is one of the main goals of clinical applicability of cell therapy for heart failure. CSCs, obtained from human myocardial bioptic specimens and grown as cardiospheres (CSps) and cardiosphere-derived cells (CDCs), can engraft and partially regenerate the infarcted myocardium, as previously described. In this paper we assessed the hypothesis that exposure of CSps and CDCs to extremely low-frequency electromagnetic fields (ELF-EMFs), tuned at Ca2+ ion cyclotron energy resonance (Ca2+-ICR), may drive their differentiation towards a cardiac-specific phenotype.

METHODS AND RESULTS

A significant increase in the expression of cardiac markers was observed after 5 days of exposure to Ca2+-ICR in both human CSps and CDCs, as evidenced at transcriptional, translational, and phenotypical levels. Ca2+ mobilization among intracellular storages was observed and confirmed by compartmentalized analysis of Ca2+ fluorescent probes.

CONCLUSIONS

These results suggest that ELF-EMFs tuned at Ca2+-ICR could be used to drive cardiac-specific differentiation in adult cardiac progenitor cells without any pharmacological or genetic manipulation of the cells that will be used for therapeutic purposes.

Ion cyclotron resonance as a tool in regenerative medicine

The identification of suitable stem cell cultures and differentiating conditions that are free of xenogenic growth supplements is an important step in finding the clinical applicability of cell therapy in two important fields of human medicine: heart failure and bone remodeling, growth and repair. We recently demonstrated the possibility of obtaining cardiac stem cells (CSCs) from human endomyocardial biopsy specimens. CSCs self-assemble into multi-cellular clusters known as cardiospheres (CSps) that engraft and partially regenerate infarcted myocardium. CSps and cardiosphere-derived-cells (CDCs) were exposed for five days in an incubator regulated for temperature, humidity, and CO(2) inside a solenoid system. This system was placed in a magnetically shielded room. The cells were exposed simultaneously to a static magnetic field (MF) and a parallel low-alternating frequency MF, close to the cyclotron frequency corresponding to the charge/mass ratio of the Ca(++) ion. In this exposure condition, CSps and CDCs modulate their differentiation turning on cardiogenesis and turning off vasculogenesis. Cardiac markers such as troponin I (TnI) and myosin heavy chain (MHC) were up-regulated. Conversely, angiogenic markers such as vascular endothelial growth factor (VEGF) and kinase domain receptor (KDR) were down-regulated as evidenced by immunocytochemistry. Exposure to the 7 Hz calcium ion cyclotron resonance (ICR) frequency can modulate the cardiogenic vs. angiogenic differentiation process of ex vivo expanded CSCs. This may pave the way for novel approaches in tissue engineering and cell therapy. With regard to bone remodeling, it has been suggested that bone marrow-derived mesenchymal stem cells (MSC) may be considered as a potential therapeutic tool. Using the Ca(++)-dependent specific differentiation potential of the ELF-MF 7 Hz ICR, we show here that exposure of human MSC to these same MF conditions enhanced the expression of osteoblast differentiation markers such as alkaline phosphatase, osteocalcin, and osteopontin, as analyzed by real-time quantitative PCR, without affecting cell proliferation. As expected, while the differentiation marker factors were up regulated, the ICR electromagnetic field down regulated osteoprotegerin gene expression, a critical regulator of postnatal skeletal development and homeostasis in humans as well as mice.

UVB-radiation-induced apoptosis in Jurkat cells: a coordinated fourier transform infrared spectroscopy-flow cytometry study

We studied the induction of apoptosis in Jurkat cells by UVB radiation (wavelength 290-320 nm) at a dose of 310 mJ/ cm2. We combined Fourier transform infrared (FTIR) spectroscopy with flow cytometry to determine whether the combination of both techniques could provide new and improved information about cell modifications. To do this, we looked for correspondences and correlations between spectroscopy and flow cytometry data and found three highly probable spectroscopic markers of apoptosis. The behavior of the wave number shift of both the Amide I beta-sheet component and the area of the 1083 cm(-1) band reproduced, with a high correlation, the behavior of the early apoptotic cell population, while the behavior of the Amide I area showed a high correlation with the early plus late apoptotic cell population.

Extremely low frequency electromagnetic field exposure promotes differentiation of pituitary corticotrope-derived AtT20 D16V cells

The pituitary corticotrope-derived AtT20 D16V cell line responds to nerve growth factor (NGF) by extending neurite-like processes and differentiating into neurosecretory-like cells. The aim of this work is the study of the effect of extremely low frequency electromagnetic fields (ELF-EMF) at a frequency of 50 Hz on these differentiation activities. To establish whether exposure to the field could influence the molecular biology of the cells, they were exposed to a magnetic flux density of 2 milli-Tesla (mT). Intracellular calcium ([Ca2+]i) and intracellular pH (pHi) were monitored in single exposed AtT20 D16V cells using fluorophores Indo-1 and SNARF for [Ca2+]i and pHi, respectively. Single-cell fluorescence microscopy showed a statistically significant increase in [Ca2+]i followed by a drop in pHi in exposed cells. Both scanning electron microscopy (SEM) and transmission microscopy of exposed AtT20 D16V cells show morphological changes in plasma membrane compared to non-exposed cells; this modification was accompanied by a rearrangement in actin filament distribution and the emergence of properties typical of peptidergic neuronal cells-the appearance of secretory-like granules in the cytosol and the increase of synaptophysin in synaptic vesicles, changes typical of neurosecretory-like cells. Using a monoclonal antibody toward the neurofilament protein NF-200 gave additional evidence that exposed cells were in an early stage of differentiation compared to control. Pre-treatment with 0.3 microM nifedipine, which specifically blocks L-type Ca2+ channels, prevented NF-200 expression in AtT20 D16V exposed cells. The above findings demonstrate that exposure to 50 Hz ELF-EMF is responsible for the premature differentiation in AtT20 D 16 V cells.

Haem conformation of amphibian nytrosylhaemoglobins detected by XANES spectroscopy

We investigated for the first time the haem stereochemistry in the nitrosylated derivative of two amphibian haemoglobins, Xenopus laevis and Ambystoma mexicanum, by means of X-ray absorption spectroscopy technique with the aim to explain the relationships between the active site structure and physiological function of these proteins, compared to that from humans. Our results show that while the Fe site local structure of human HbNO is modulated by an allosteric effector such as IHP shifting the T-R equilibrium towards the T-state, the Fe site local structure of amphibians HbNO is stabilized in a particularly tensed T-state also without IHP.

Analysis of SNAP-25 immunoreactivity in hippocampal inhibitory neurons during development in culture and in situ

Synaptosomal associated protein of 25 kDa (SNAP-25) is a component of the soluble N-ethylmaleimide-sensitive fusion protein (NSF) attachment protein receptor (SNARE) complex which plays a central role in synaptic vesicle exocytosis. We have previously demonstrated that adult rat hippocampal GABAergic synapses, both in culture and in brain, are virtually devoid of SNAP-25 immunoreactivity and are less sensitive to the action of botulinum toxin type A, which cleaves this SNARE protein [Neuron 41 (2004) 599]. In the present study, we extend our findings to the adult mouse hippocampus and we also provide demonstration that hippocampal inhibitory synapses lacking SNAP-25 labeling belong to parvalbumin-, calretinin- and cholecystokinin-positive interneurons. A partial colocalization between SNAP-25 and glutamic acid decarboxylase is instead detectable in developing mouse hippocampus at P0 and, at a lesser extent, at P5. In rat embryonic hippocampal cultures at early developmental stages, SNAP-25 immunoreactivity is detectable in a percentage of GABAergic neurons, which progressively reduces with time in culture. Consistent with the presence of the substrate, botulinum toxin type A is partially effective in inhibiting synaptic vesicle recycling in immature GABAergic neurons. Since SNAP-25, beside its role as a SNARE protein, is involved in additional processes, such as neurite outgrowth and regulation of calcium dynamics, the presence of higher levels of the protein at specific stages of neuronal differentiation may have implications for the construction and for the functional properties of brain circuits.

Dynamic properties of an oriented lipid/DNA complex studied by neutron scattering

The formation of lipid-DNA (CL-DNA) complexes called lipoplexes, proposed as DNA vectors in gene therapy, is obtained by adding DNA to a solution containing liposomes composed of cationic and neutral lipids. The structural and dynamic properties of such lipoplexes are determined by a coupling between the electrostatic interactions and the elastic parameters of the lipid mixture. An attempt to achieve a better understanding of the structure-dynamics relationship is reported herein. In particular, an elastic neutron scattering investigation of DOTAP-DOPC (dioleoyl trimethylammonium propane-dioleoyl phosphatidylcoline) complexed with DNA is described. Proton dynamics in this oriented CL-DNA lipoplex is found to be strongly dependent upon DNA concentration. Our results show that a substantial modification of the membrane dynamics is accompanied by the balancing of the total net charge inside the complex, together with the consequent displacement of interlayer water molecules.

Cell-metal interaction studied by cytotoxic and FT-IR spectroscopic methods

The main purpose of this work is to investigate the possibility of utilizing both a classical biological method to test cytotoxicity and a physical measurement procedure as the FT-IR spectroscopy to study the interaction between cells lines and heavy metals. Jurkart, a lymphocyte cell line, was treated with cadmium chloride, cadmium oxide and the organic germanium compound named Ge-oxy-132. The utilized value of heavy metal concentration allows us to obtain significant results with both methods and with all metals. In fact by using lower values of concentration any effect is revealed after treatment with germanium. The results of the simultaneous measurements by both experimental procedures are here reported for the first time and show that, while the cytotoxic effects of the two cadmium compounds are confirmed, the organic germanium compound reveals a very different and interesting interaction with Jurkart cells. The behaviour of the Jurkart cells upon the uptake of cadmium or organic germanium is very different: while treatment with CdO and CdCl(2) determines proteins denaturation and lipids oxidation in cells until the death, these processes are not revealed after Ge-oxy-132 treatment.

Structural characterization of a new lipid/DNA complex showing a selective transfection efficiency in ovarian cancer cells

We investigated, for the first time, by using Energy Dispersive X-ray Diffraction, the structure of a new ternary cationic liposome formulated with dioleoyl trimethylammonium propane (DOTAP), 1,2-dioleoyl-3-phosphatidylethanolamine (DOPE) and cholesterol (Chol) (DDC) which has been recently found to have a selective high gene transfer ability in ovarian cancer cells. Our structural results provide a further experimental support to the widely accepted statement that there is not a simple and direct correlation between structure and transfection efficiency and that the factors controlling cationic lipid/DNA (CL-DNA) complexes-mediated gene transfer depend not only on the formulations of the cationic liposomes and their thermodynamic phase, but also significantly on the cell properties.

Effects of extremely low frequency (50 Hz) magnetic field on morphological and biochemical properties of human keratinocytes

We investigated the effects on human keratinocytes (HaCaT) of exposure to a sinusoidal magnetic field of 2 mT (50 Hz). These cells are a good model for studying interaction of nonionising radiation, because they are not shielded from fields in vivo and also because they are resistant to both mechanical and thermal stimuli. We performed scanning microscopy which showed modification in shape and morphology in exposed cells. This modification is related to differential actin distribution as revealed by phalloidin fluorescence analysis. Moreover, the exposed cells show increased clonogenic capacity, as well as increased cellular growth as showed by clonogenicity assays and growth curves. Indirect immunofluorescence analysis using a fluorescent antibody against involucrin and beta4 integrin, which are respectively differentiation and adhesion markers, revealed an increase of involucrin expression and segregation of beta4 integrin in the cell membrane in cells exposed to 50 Hz; a higher percentage of the exposed cells shows a modified pattern of adhesion and differentiation markers. We also present evidence that exposure of HaCaT cells can interfere with protein kinase activity. Our observations confirm the hypothesis that electromagnetic fields at 50 Hz may modify cell membrane morphology and interfere with initiation of the signal cascade pathway and cellular adhesion.

[Drugs and closed-angle glaucoma risk]

Closed-angle glaucomas arise among predisposed patients (narrow iridocorneal angle) in response to various stimuli. Most of the attacks are of iatrogenic origin: all the topical and systemic mydriatic drugs can provoke an angle closure glaucoma attack. Dangerous active ingredients with closed-angle glaucoma are active substances with anticholinergic activity (peripheral action, central action, with anticholinergic side-effects), active ingredients with sympathomimetic alpha activity (alpha 1, alpha and beta with indirect effects), and the active ingredients with parasympathomimetic activity (anticholinesterases). The proprietary medicine, whether or not they are included in the French dictionary Vidal((R)), are classified according to the administration route and their different indications. The closed-angle glaucoma risk after administration of these drugs is noted in the items'contraindications and precautions in the summary of the product characteristics enclosed in the marketing authorization.

Three dimensional (3D) analysis of the morphological changes induced by 50 Hz magnetic field exposure on human lymphoblastoid cells (Raji)

Human Raji B lymphoid cells after exposure for 64 h to a 1 mT (rms) 50 Hz sinusoidal magnetic field showed a reorganization of membrane and cytoskeletal components. Atomic force microscopy in air revealed several modifications in 80% of the exposed cells, such as loss of microvilli-like structures followed by progressive appearance of membrane introflections. This change in plasma membrane morphology was also accompanied by a different actin distribution, as detected by phalloidin fluorescence. These observations support our previous hypothesis that electric and magnetic fields may modify the plasma membrane structure.

Effect of extremely low frequency (ELF) magnetic field exposure on morphological and biophysical properties of human lymphoid cell line (Raji)

Human B lymphoid cells (Raji) were exposed for 72 h to a 50 Hz sinusoidal magnetic field at a density of 2 milliTesla (rms). The results of exposure showed a decrease in membrane fluidity as detected by Laurdan emission spectroscopy and DPH fluorescence polarization. Field exposure also resulted in a reorganization of cytoskeletal components. Scanning electron microscopy (SEM) revealed a loss of microvilli in the exposed cells. This change in plasma membrane morphology was accompanied by a different actin distribution, as detected by phalloidin fluorescence. We also present evidence that EMF exposure of Raji cells can interfere with protein phosphorylation. Our observations confirm the hypothesis that electric and magnetic fields may modify the plasma membrane structure and interfere with the initiation of the signal cascade pathways.

Attempts to use liposomes and RBC ghosts as vectors in drug and antisense therapy of virus infection

Selective targeting of drugs or oligonucleotide for the treatment of viral diseases or cancer is the objective of new strategies that pursue therapy optimization and reduction of toxicity. In this work we report two protocols based on encapsulation of anti-human immunodeficiency virus drugs within targeted liposomes or erythrocytes. Both have been shown to be effective for the specific delivery of drugs or oligonucleotide in the treatment of viral infection.

Exposure to a 50 Hz electromagnetic field induces activation of the Epstein-Barr virus genome in latently infected human lymphoid cells

The EBV genome in latently infected lymphoid cells offers an opportunity to follow effects on the transcriptional and translational product clearly distinguishable from those of the host cell genome. Exposure of Akata cells, a human lymphoid cell line latently infected by the EBV genome, to a 50 Hz EMF resulted in an increased number of cells expressing the virus early antigens. This finding provides additional evidence that DNA can be modulated by a magnetic field.

Role of membrane fluidity in Epstein Barr virus (EBV) infectivity on Akata cell line

Infection of Epstein Barr virus (EBV) to its host cells is initiated by the attachment of the glycoprotein gp 350/220 to the CR2 molecule. We used the sensitivity at the polar environment of the fluorescent probe Laurdan to study the membrane viscosity distribution from single leaving cells on two lymphoid cell lines Raji and Akata. Lipid analysis on both cells line demonstrated a lower cholesterol to phospholipid molar ratio on Akata than Raji cells. Cell fluidity analysis by Laurdan generalized emission polarization (GP) or by DPH polarization, indicated that membrane viscosity of Akata was lower than Raji cells. This difference was correlated to the increased susceptibility of Akata cells in expressing EBV early antigens (EA) after EBV superinfection.

Quantified electroencephalographic correlates of relative frontal or parietal hypoperfusion in dementia

The authors examined the presence of specific quantified electroencephalographic (qEEG) changes in dementia patients with relatively lower frontal or parietal blood perfusion as demonstrated by SPECT. Over all brain regions, patients with relatively lower parietal perfusion showed significantly higher theta relative power than demented patients with relatively lower frontal perfusion or normal control subjects. Dementia patients with relatively lower frontal perfusion showed no differences from age-comparable normal control subjects in qEEG variables. These findings 1) suggest that usefulness of qEEG for the diagnosis of dementia is restricted to a subgroup of patients with the typical SPECT pattern of parietal blood hypoperfusion and 2) demonstrate that the qEEG changes typical of dementia are not related to perfusion deficits in frontal brain areas.

Quantified electroencephalographic changes in depressed patients with and without dementia

We carried out quantified electroencephalograms (qEEG) in 17 patients with probable Alzheimer's disease (AD), who also met the DSM-III-R criteria for either dysthymia or major depression, and 18 AD patients with comparable intellectual impairment but no depression, 13 patients with depression but no AD, and 10 age-matched normal controls. There was a significant effect for depression in alpha relative power: depressed patients (with or without AD) showed a significantly lower alpha relative power in the right posterior region as compared to nondepressed patients; however, this change was observed over the right hemisphere in depressed non-AD patients, and in left, medial, and right posterior regions in depressed-AD patients. Depressed patients without AD showed a significant global decrease in delta power, whereas depressed patients with AD showed significant increments in delta power in posterior brain areas. In conclusion, AD patients with depression showed qEEG changes that were significantly different from qEEG changes in depressed non-AD patients.

Fusion of EBV with the surface of receptor-negative human hepatoma cell line Li7A permits virus penetration and infection

Our preliminary data suggest that Epstein-Barr virus (EBV) is able to bind to and fuse with the surface membranes of hepatoma cell line Li7A. In order to obtain further evidence, we utilized the relief of rhodamine fluorescence to monitor whether fusion would also take place when Li7A cells were exposed to experimental conditions such as neutral or low pH. It is well known that for some viruses, protonation in the endosomal compartment is needed to trigger the fusion. We show, furthermore, that the rate and extent of fusion are not affected by pretreatment of the cells with agents known to elevate the lysosomal and ensodomal pH, such as chloroquine or NH4Cl (lysosomotropic agent). By indirect immunofluorescence assay, in addition, we confirmed the binding of the EBV to the Li7A cell surface membrane. We attempted finally to correlate the above processes with successful infection of Li7A cells by EBV detected using the polymerase chain reaction technique. In spite of the apparent lack of viral receptor CD21, these nonlymphoid cells appeared susceptible to EBV penetration and infection through fusion with the plasma membrane at the surface of the cells.

Engineered liposomes and virosomes for delivery of macromolecules

In order to utilize virosomes or proteoliposomes for the delivery of drugs or macromolecules to specific pathologic target cells we elaborated a system to shuttle drugs to solid tissue (liver) as well as to the macrophages, a crucial cellular compartment of the immune system. Using virosomes prepared from the P3HR1 strain of Epstein-Barr virus, we demonstrated that these particles fused with human hepatocarcinoma cell line Li7A and therefore might be used as drug vectors. Furthermore, we report that proteoliposomes prepared by reconstituting in a cocktail of phosphatidylserine-phosphatidylcholine the anion transporter band 3 protein markedly increased the phagocytic activity of macrophages in culture. This could represent a new device to be used as a drug delivery system to enhance specific macrophagic functions.