Nonspherical ultrasound microbubbles

Surface tension provides microbubbles (MB) with a perfect spherical shape. Here, we demonstrate that MB can be engineered to be nonspherical, endowing them with unique features for biomedical applications. Anisotropic MB were generated via one-dimensionally stretching spherical poly(butyl cyanoacrylate) MB above their glass transition temperature. Compared to their spherical counterparts, nonspherical polymeric MB displayed superior performance in multiple ways, including i) increased margination behavior in blood vessel-like flow chambers, ii) reduced macrophage uptake in vitro, iii) prolonged circulation time in vivo, and iv) enhanced blood-brain barrier (BBB) permeation in vivo upon combination with transcranial focused ultrasound (FUS). Our studies identify shape as a design parameter in the MB landscape, and they provide a rational and robust framework for further exploring the application of anisotropic MB for ultrasound-enhanced drug delivery and imaging applications.

Shape-specific microfabricated particles for biomedical applications: a review

The storied history of controlled the release systems has evolved over time; from degradable drug-loaded sutures to monolithic zero-ordered release devices and nano-sized drug delivery formulations. Scientists have tuned the physico-chemical properties of these drug carriers to optimize their performance in biomedical/pharmaceutical applications. In particular, particle drug delivery systems at the micron size regime have been used since the 1980s. Recent advances in micro and nanofabrication techniques have enabled precise control of particle size and geometry-here we review the utility of microplates and discoidal polymeric particles for a range of pharmaceutical applications. Microplates are defined as micrometer scale polymeric local depot devices in cuboid form, while discoidal polymeric nanoconstructs are disk-shaped polymeric particles having a cross-sectional diameter in the micrometer range and a thickness in the hundreds of nanometer range. These versatile particles can be used to treat several pathologies such as cancer, inflammatory diseases and vascular diseases, by leveraging their size, shape, physical properties (e.g., stiffness), and component materials, to tune their functionality. This review highlights design and fabrication strategies for these particles, discusses their applications, and elaborates on emerging trends for their use in formulations.

Boosting nanomedicine performance by conditioning macrophages with methyl palmitate nanoparticles

Surface PEGylation, biological camouflage, shape and stiffness modulation of nanoparticles as well as liver blockade and macrophage depletion have all improved the blood longevity of nanomedicines. Yet, the mononuclear phagocytic system still recognizes, sequesters, and processes the majority of blood borne particles. Here, the natural fatty acid methyl palmitate is combined with endogenous blood components - albumin - realizing ∼200 nm stable, spherical nanoparticles (MPN) capable of inducing a transient and reversible state of dormancy into macrophages. In primary bone marrow derived monocytes (BMDM), the rate of internalization of 5 different particles, ranging in size from 200 up to 2000 nm, with spherical and discoidal shapes, and made out of lipids and polymers, was almost totally inhibited after an overnight pre-treatment with 0.5 mM MPN. Microscopy analyses revealed that MPN reversibly reduced the extension and branching complexity of the microtubule network in BMDM, thus altering membrane bulging and motility. In immunocompetent mice, a 4 h pre-treatment with MPN was sufficient to redirect 2000 nm rigid particles from the liver to the lungs realizing a lung-to-liver accumulation ratio larger than 2. Also, in mice bearing U87-MG tumor masses, a 4 h pre-treatment with MPN enhanced the therapeutic efficacy of docetaxel-loaded nanoparticles significantly inhibiting tumor growth. The natural liver sequestering function was fully recovered overnight. This data would suggest that MPN pre-treatment could transiently and reversibly inhibit non-specific particle sequestration, thus redirecting nanomedicines towards their specific target tissue while boosting their anti-cancer efficacy and imaging capacity.

Cytosolic delivery of nucleic acids: The case of ionizable lipid nanoparticles

Ionizable lipid nanoparticles (LNPs) are the most clinically advanced nano-delivery system for therapeutic nucleic acids. The great effort put in the development of ionizable lipids with increased in vivo potency brought LNPs from the laboratory benches to the FDA approval of patisiran in 2018 and the ongoing clinical trials for mRNA-based vaccines against SARS-CoV-2. Despite these success stories, several challenges remain in RNA delivery, including what is known as "endosomal escape." Reaching the cytosol is mandatory for unleashing the therapeutic activity of RNA molecules, as their accumulation in other intracellular compartments would simply result in efficacy loss. In LNPs, the ability of ionizable lipids to form destabilizing non-bilayer structures at acidic pH is recognized as the key for endosomal escape and RNA cytosolic delivery. This is motivating a surge in studies aiming at designing novel ionizable lipids with improved biodegradation and safety profiles. In this work, we describe the journey of RNA-loaded LNPs across multiple intracellular barriers, from the extracellular space to the cytosol. In silico molecular dynamics modeling, in vitro high-resolution microscopy analyses, and in vivo imaging data are systematically reviewed to distill out the regulating mechanisms underlying the endosomal escape of RNA. Finally, a comparison with strategies employed by enveloped viruses to deliver their genetic material into cells is also presented. The combination of a multidisciplinary analytical toolkit for endosomal escape quantification and a nature-inspired design could foster the development of future LNPs with improved cytosolic delivery of nucleic acids.

Laparoscopic cholecystectomy for acute cholecystitis: onset of symptoms and severity grade as a tool for choosing the optimal timing

BACKGROUND

Acute cholecystitis is an acute inflammation of the gallbladder. It represents one-third of all surgical emergency hospital admissions and has significant socioeconomic impact. Laparoscopic cholecystectomy, regardless of age, is the gold standard for this disease, but the optimal timing of surgical intervention is an open issue since Tokyo guidelines 2007.

METHODS

We recruited from March 2015 to June 2018, in a retrospective study, 144 patients with acute cholecystitis and treated with laparoscopic cholecystectomy. The patients were divided into two groups: group A (n=66), operated within 72 hours and group B (n=78), between 72 hours and 1 week after the onset of symptoms. After, the two groups were further stratified by the grade of severity of acute cholecystitis in according to Tokyo guidelines: in group A, 39 patients were grade I and 27 grade II; in group B, 48 patients were grade I and 30 grade II.

RESULTS

The operative time was longer in group B patients versus group A. In group B, there was a greater difficulty in dissecting and detecting the Calot's triangle, more conversions to open, a greater mean length of hospital stay and more post-operative days. In patients with grade II, especially in the group B, were greater inflammation stage, conversions to open, difficulty in the dissection of the Calot's triangle, mean length of hospital stay and post-operative days. The operative timing within 72 hours in patients with grade I, have only advantage in the mean length of hospital stay, while in grade II, the advantages are also in the lesser difficulty in dissecting the Calot's triangle, fewer conversions and fewer post-operative days.

CONCLUSIONS

Early laparoscopic cholecystectomy for acute cholecystitis should be performed considering not only the onset of symptoms, but above all the grade of severity of AC in according with TG. Grade II, particularly, must be treated within 72 hours and by experienced surgeon.

Synthesis of Two Methotrexate Prodrugs for Optimizing Drug Loading into Liposomes

Methotrexate (MTX), a compound originally used as an anticancer drug, has also found applications in a broad variety of autoimmune disorders thanks to its anti-inflammation and immunomodulatory functions. The broad application of MTX is anyway limited by its poor solubility in biological fluids, its poor bioavailability and its toxicity. In addition, encapsulating its original form in nanoformulation is very arduous due to its considerable hydrophobicity. In this work, two strategies to efficiently encapsulate MTX into liposomal particles are proposed to overcome the limitations mentioned above and to improve MTX bioavailability. MTX solubility was increased by conjugating the molecule to two different compounds: DSPE and PEG. These two compounds commonly enrich liposome formulations, and their encapsulation efficiency is very high. By using these two prodrugs (DSPE-MTX and PEG-MTX), we were able to generate liposomes comprising one or both of them and characterized their physiochemical features and their toxicity in primary macrophages. These formulations represent an initial step to the development of targeted liposomes or particles, which can be tailored for the specific application MTX is used for (cancer, autoimmune disease or others).

Modulating Lipoprotein Transcellular Transport and Atherosclerotic Plaque Formation in ApoE-/- Mice via Nanoformulated Lipid-Methotrexate Conjugates

Macrophage inflammation and maturation into foam cells, following the engulfment of oxidized low-density lipoproteins (oxLDL), are major hallmarks in the onset and progression of atherosclerosis. Yet, chronic treatments with anti-inflammatory agents, such as methotrexate (MTX), failed to modulate disease progression, possibly for the limited drug bioavailability and plaque deposition. Here, MTX-lipid conjugates, based on 1,2-distearoyl-sn-glycero-3-phosphoethanolamine (DSPE), were integrated in the structure of spherical polymeric nanoparticles (MTX-SPNs) or intercalated in the lipid bilayer of liposomes (MTX-LIP). Although, both nanoparticles were colloidally stable with an average diameter of ∼200 nm, MTX-LIP exhibited a higher encapsulation efficiency (>70%) and slower release rate (∼50% at 10 h) compared to MTX-SPN. In primary bone marrow derived macrophages (BMDMs), MTX-LIP modulated the transcellular transport of oxLDL more efficiently than free MTX mostly by inducing a 2-fold overexpression of ABCA1 (regulating oxLDL efflux), while the effect on CD36 and SRA-1 (regulating oxLDL influx) was minimal. Furthermore, in BMDMs, MTX-LIP showed a stronger anti-inflammatory activity than free MTX, reducing the expression of IL-1β by 3-fold, IL-6 by 2-fold, and also moderately of TNF-α. In 28 days high-fat-diet-fed apoE-/- mice, MTX-LIP reduced the mean plaque area by 2-fold and the hematic amounts of RANTES by half as compared to free MTX. These results would suggest that the nanoenhanced delivery to vascular plaques of the anti-inflammatory DSPE-MTX conjugate could effectively modulate the disease progression by halting monocytes' maturation and recruitment already at the onset of atherosclerosis.

A nation-wide survey on emotional and psychological impacts of COVID-19 social distancing

OBJECTIVE

Social distancing is crucial in order to flatten the curve of COVID-19 virus spreading. Isolation, scarcity of resources and the lack of social contacts may have produced a negative impact on people's emotions and psychological well-being. This study aims to explore the reasons and the ways through which social distancing generates negative emotions in individuals who experienced the lockdown. To a larger extent, the objective is to check the existence of relations between negative emotions and the satisfaction of basic needs.

MATERIALS AND METHODS

In Italy 140,656 online interviews were collected from March 22 to April 2, 2020. Data analysis was carried out using mono and bivariate statistical analysis, K-means clustering and the Principal Components Analysis (PCA). The parameters for the identification of six clusters were: the intensity of the respondent's basic emotions and the layers of Maslow's hierarchy of needs.

RESULTS

The majority of people involved in an emergency situation, implying a collapse of social contacts, experience some kind of emotional reactions. In our study, we found a correlation between basic emotions and Maslow's hierarchy of needs. In times of crisis, the most basic needs are the physiological ones. Fear, anger and sadness are predominant in all population groups; anger and disgust mainly appear when people are exposed to the risk of not being able to meet subsistence needs, thus perceiving a lack of economic security.

CONCLUSIONS

The well-known Maslow's theory of human needs seems to fit well with the outbreak of negative emotions in the context of COVID-19. This study demonstrates the existence of links between negative emotions and primary needs that mainly refer to the first three levels of Maslow's pyramid. As a result of COVID-19 worldwide pandemic, many people have been sucked into the bottom layers of the pyramid. This change in individual basic needs has triggered a relevant transformation in individual emotional status and a shift towards negative emotions.

Leaf-Inspired Authentically Complex Microvascular Networks for Deciphering Biological Transport Process

The vascular transport of molecules, cells, and nanoconstructs is a fundamental biophysical process impacting tissue regeneration, delivery of nutrients and therapeutic agents, and the response of the immune system to external pathogens. This process is often studied in single-channel microfluidic devices lacking the complex tridimensional organization of vascular networks. Here, soft lithography is employed to replicate the vein system of a Hedera elix leaf on a polydimethilsiloxane (PDMS) template. The replica is then sealed and connected to an external pumping system to realize an authentically complex microvascular network. This satisfies energy minimization criteria by Murray's law and comprises a network of channels ranging in size from capillaries (∼50 μm) to large arterioles and venules (∼400 μm). Micro-PIV (micro-particle image velocimetry) analysis is employed to characterize flow conditions in terms of streamlines, fluid velocity, and flow rates. To demonstrate the ability to reproduce physiologically relevant transport processes, two different applications are demonstrated: vascular deposition of tumor cells and lysis of blood clots. To this end, conditions are identified to culture cells within the microvasculature and realize a confluent endothelial monolayer. Then, the vascular deposition of circulating breast (MDA-MB 231) cancer cells is documented throughout the network under physiologically relevant flow conditions. Firm cell adhesion mostly occurs in channels with low mean blood velocity. As a second application, blood clots are formed within the chip by mixing whole blood with a thrombin solution. After demonstrating the blood clot stability, tissue plasminogen activator (tPA) and tPA-carrying nanoconstructs (tPA-DPNs) are employed as thrombolytics. In agreement with previous data, clot dissolution is equally induced by tPA and tPA-DPNs. The proposed leaf-inspired chip can be efficiently used to study a variety of vascular transport processes in complex microvascular networks, where geometry and flow conditions can be modulated and monitored throughout the experimental campaign.

Ultrasound delivery of Surface Enhanced InfraRed Absorption active gold-nanoprobes into fibroblast cells: a biological study via Synchrotron-based InfraRed microanalysis at single cell level

Ultrasound (US) induced transient membrane permeabilisation has emerged as a hugely promising tool for the delivery of exogenous vectors through the cytoplasmic membrane, paving the way to the design of novel anticancer strategies by targeting functional nanomaterials to specific biological sites. An essential step towards this end is the detailed recognition of suitably marked nanoparticles in sonoporated cells and the investigation of the potential related biological effects. By taking advantage of Synchrotron Radiation Fourier Transform Infrared micro-spectroscopy (SR-microFTIR) in providing highly sensitive analysis at the single cell level, we studied the internalisation of a nanoprobe within fibroblasts (NIH-3T3) promoted by low-intensity US. To this aim we employed 20 nm gold nanoparticles conjugated with the IR marker 4-aminothiophenol. The significant Surface Enhanced Infrared Absorption provided by the nanoprobes, with an absorbance increase up to two orders of magnitude, allowed us to efficiently recognise their inclusion within cells. Notably, the selective and stable SR-microFTIR detection from single cells that have internalised the nanoprobe exhibited clear changes in both shape and intensity of the spectral profile, highlighting the occurrence of biological effects. Flow cytometry, immunofluorescence and murine cytokinesis-block micronucleus assays confirmed the presence of slight but significant cytotoxic and genotoxic events associated with the US-nanoprobe combined treatments. Our results can provide novel hints towards US and nanomedicine combined strategies for cell spectral imaging as well as drug delivery-based therapies.

Erythrocyte-Inspired Discoidal Polymeric Nanoconstructs Carrying Tissue Plasminogen Activator for the Enhanced Lysis of Blood Clots

Tissue plasminogen activator (tPA) is the sole approved therapeutic molecule for the treatment of acute ischemic stroke. Yet, only a small percentage of patients could benefit from this life-saving treatment because of medical contraindications and severe side effects, including brain hemorrhage, associated with delayed administration. Here, a nano therapeutic agent is realized by directly associating the clinical formulation of tPA to the porous structure of soft discoidal polymeric nanoconstructs (tPA-DPNs). The porous matrix of DPNs protects tPA from rapid degradation, allowing tPA-DPNs to preserve over 70% of the tPA original activity after 3 h of exposure to serum proteins. Under dynamic conditions, tPA-DPNs dissolve clots more efficiently than free tPA, as demonstrated in a microfluidic chip where clots are formed mimicking in vivo conditions. At 60 min post-treatment initiation, the clot area reduces by half (57 ± 8%) with tPA-DPNs, whereas a similar result (56 ± 21%) is obtained only after 90 min for free tPA. In murine mesentery venules, the intravenous administration of 2.5 mg/kg of tPA-DPNs resolves almost 90% of the blood clots, whereas a similar dose of free tPA successfully recanalizes only about 40% of the treated vessels. At about 1/10 of the clinical dose (1.0 mg/kg), tPA-DPNs still effectively dissolve 70% of the clots, whereas free tPA works efficiently only on 16% of the vessels. In vivo, discoidal tPA-DPNs outperform the lytic activity of 200 nm spherical tPA-coated nanoconstructs in terms of both percentage of successful recanalization events and clot area reduction. The conjugation of tPA with preserved lytic activity, the deformability and blood circulating time of DPNs together with the faster blood clot dissolution would make tPA-DPNs a promising nanotool for enhancing both potency and safety of thrombolytic therapies.

Targeting Inflammation With Nanosized Drug Delivery Platforms in Cardiovascular Diseases: Immune Cell Modulation in Atherosclerosis

Atherosclerosis (AS) is a disorder of large and medium-sized arteries; it consists in the formation of lipid-rich plaques in the intima and inner media, whose pathophysiology is mostly driven by inflammation. Currently available interventions and therapies for treating atherosclerosis are not always completely effective; side effects associated with treatments, mainly caused by immunodepression for anti-inflammatory molecules, limit the systemic administration of these and other drugs. Given the high degree of freedom in the design of nanoconstructs, in the last decades researchers have put high effort in the development of nanoparticles (NPs) formulations specifically designed for either drug delivery, visualization of atherosclerotic plaques, or possibly the combination of both these and other functionalities. Here we will present the state of the art of these subjects, the knowledge of which is necessary to rationally address the use of NPs for prevention, diagnosis, and/or treatment of AS. We will analyse the work that has been done on: (a) understanding the role of the immune system and inflammation in cardiovascular diseases, (b) the pathological and biochemical principles in atherosclerotic plaque formation, (c) the latest advances in the use of NPs for the recognition and treatment of cardiovascular diseases, (d) the cellular and animal models useful to study the interactions of NPs with the immune system cells.

Hierarchical Microplates as Drug Depots with Controlled Geometry, Rigidity, and Therapeutic Efficacy

A variety of microparticles have been proposed for the sustained and localized delivery of drugs with the objective of increasing therapeutic indexes by circumventing filtering organs and biological barriers. Yet, the geometrical, mechanical, and therapeutic properties of such microparticles cannot be simultaneously and independently tailored during the fabrication process to optimize their performance. In this work, a top-down approach is employed to realize micron-sized polymeric particles, called microplates (μPLs), for the sustained release of therapeutic agents. μPLs are square hydrogel particles, with an edge length of 20 μm and a height of 5 μm, made out of poly(lactic- co-glycolic acid) (PLGA). During the synthesis process, the μPL Young's modulus can be varied from 0.6 to 5 MPa by changing the PLGA amounts from 1 to 7.5 mg, without affecting the μPL geometry while matching the properties of the surrounding tissue. Within the porous μPL matrix, different classes of therapeutic payloads can be incorporated including molecular agents, such as anti-inflammatory dexamethasone (DEX), and nanoparticles containing imaging and therapeutic molecules themselves, thus originating a truly hierarchical platform. As a proof of principle, μPLs are loaded with free DEX and 200 nm spherical polymeric nanoparticles, carrying DEX molecules (DEX-SPNs). Electron and fluorescent confocal microscopy analyses document the uniform distribution and stability of molecular and nanoagents within the μPL matrix. This multiscale, hierarchical microparticle releases DEX for at least 10 days. The inclusion of DEX-SPNs serves to minimize the initial burst release and modulate the diffusion of DEX molecules out of the μPL matrix. The biopharmacological and therapeutic properties together with the fine tuning of geometry and mechanical stiffness make μPLs a unique polymeric depot for the potential treatment of cancer, cardiovascular, and chronic, inflammatory diseases.

Modulating Phagocytic Cell Sequestration by Tailoring Nanoconstruct Softness

The effect of nanoparticle size, shape, and surface properties on cellular uptake has been extensively investigated for its basic science and translational implications. Recently, softness is emerging as a design parameter for modulating the interaction of nanoparticles with cells and the biological microenvironment. Here, circular, quadrangular, and elliptical polymeric nanoconstructs of different sizes are realized with a Young's modulus ranging from ∼100 kPa (soft) to 10 MPa (rigid). The interaction of these nanoconstructs with professional phagocytic cells is assessed via confocal microscopy and flow cytometry analyses. Regardless of the size and shape, softer nanoconstructs evade cellular uptake up to 5 times more efficiently, by bone-marrow-derived monocytes, as compared to rigid nanoconstructs. Soft circular and quadrangular nanoconstructs are equally uptaken by professional phagocytic cells (<15%); soft elliptical particles are more avidly internalized (<60%) possibly because of the larger size and elongated shape, whereas over 70% of rigid nanoconstructs of any shape and size are uptaken. Inhibition of actin polymerization via cytochalasin D reduces the internalization propensity for all nanoconstruct types. High-resolution live cell microscopy documents that soft nanoconstructs mostly establish short-lived (<30 s) interactions with macrophages, thus diminishing the likelihood of recognition and internalization. The bending stiffness is identified as a discriminating factor for internalization, whereby particles with a bending stiffness slightly higher than cells would more efficiently oppose internalization as compared to stiffer or softer particles. These results confirm that softness is a key parameter in modulating the behavior of nanoparticles and are expected to inspire the design of more efficient nanoconstructs for drug delivery, biomedical imaging, and immunomodulatory therapies.

Differential effects on membrane permeability and viability of human keratinocyte cells undergoing very low intensity megasonic fields

Among different therapeutic applications of Ultrasound (US), transient membrane sonoporation (SP) - a temporary, non-lethal porosity, mechanically induced in cell membranes through US exposure - represents a compelling opportunity towards an efficient and safe drug delivery. Nevertheless, progresses in this field have been limited by an insufficient understanding of the potential cytotoxic effects of US related to the failure of the cellular repair and to the possible activation of inflammatory pathway. In this framework we studied the in vitro effects of very low-intensity US on a human keratinocyte cell line, which represents an ideal model system of skin protective barrier cells which are the first to be involved during medical US treatments. Bioeffects linked to US application at 1 MHz varying the exposure parameters were investigated by fluorescence microscopy and fluorescence activated cell sorting. Our results indicate that keratinocytes undergoing low US doses can uptake drug model molecules with size and efficiency which depend on exposure parameters. According to sub-cavitation SP models, we have identified the range of doses triggering transient membrane SP, actually with negligible biological damage. By increasing US doses we observed a reduced cells viability and an inflammatory gene overexpression enlightening novel healthy relevant strategies.

Ameliorating Amyloid-β Fibrils Triggered Inflammation via Curcumin-Loaded Polymeric Nanoconstructs

Inflammation is a common hallmark in several diseases, including atherosclerosis, cancer, obesity, and neurodegeneration. In Alzheimer's disease (AD), growing evidence directly correlates neuronal damage with inflammation of myeloid brain cells, such as microglia. Here, polymeric nanoparticles were engineered and characterized for the delivery of anti-inflammatory molecules to macrophages stimulated via direct incubation with amyloid-β fibers. 200 nm spherical polymeric nanoconstructs (SPNs) and 1,000 nm discoidal polymeric nanoconstructs (DPNs) were synthesized using poly(lactic-co-glycolic acid) (PLGA), polyethylene glycol (PEG), and lipid chains as building blocks. First, the internalization propensity in macrophages of both nanoparticles was assessed via cytofluorimetric and confocal microscopy analyses, demonstrating that SPNs are by far more rapidly taken up as compared to DPNs (99.6 ± 0.11 vs 14.4 ± 0.06%, within 24 h). Then, Curcumin-loaded SPNs (Curc-SPNs) were realized by encapsulating Curcumin, a natural anti-inflammatory molecule, within the PLGA core of SPNs. Finally, Curc-SPNs were shown to diminish up to 6.5-fold the production of pro-inflammatory cytokines-IL-1β; IL-6, and TNF-α-in macrophages stimulated via amyloid-β fibers. Although more sophisticated in vitro models and systematic analyses on the blood-brain barrier permeability are critically needed, these findings hold potential in the development of nanoparticles for modulating inflammation in AD.

Deformable Discoidal Polymeric Nanoconstructs for the Precise Delivery of Therapeutic and Imaging Agents

Over the last 15 years, a plethora of materials and different formulations have been proposed for the realization of nanomedicines. Yet drug-loading efficiency, sequestration by phagocytic cells, and tumor accumulation are sub-optimal. This would imply that radically new design approaches are needed to propel the clinical integration of nanomedicines, overcoming well-accepted clichés. This work briefly reviews the use of deformable discoidal nanoconstructs as a novel delivery strategy for therapeutic and imaging agents. Inspired by blood cell behavior, these nanoconstructs are designed to efficiently navigate the circulatory system, minimize sequestration by phagocytic cells, and recognize the tortuous angiogenic microvasculature of neoplastic masses. This article discusses the notion of nanoparticle margination and vascular adhesion, as well as advantages associated with deformable particles. Finally, details on the synthesis, physico-chemical properties, and in vivo characterization of discoidal polymeric nanoconstructs are provided, with particular emphasis on their ability to independently control size, shape, surface properties, and mechanical stiffness. These nanoconstructs could help in gaining a deeper understanding of the mechanisms regulating the behavior of nanomedicines and identifying optimal delivery strategies for patient-specific therapeutic interventions.

Antibody-mediated inhibition of Nogo-A signaling promotes neurite growth in PC-12 cells

The use of a monoclonal antibody to block the neurite outgrowth inhibitor Nogo-A has been of great interest for promoting axonal recovery as a treatment for spinal cord injury. While several cellular and non-cellular assays have been developed to quantify the bioactive effects of Nogo-A signaling, demand still exists for the development of a reliable approach to characterize the effectiveness of the anti-Nogo-A antibody. In this study, we developed and validated a novel cell-based approach to facilitate the biological quantification of a Nogo-A antibody using PC-12 cells as an in vitro neuronal cell model. Changes in the mRNA levels of the neuronal differentiation markers, growth-associated protein 43 and neurofilament light-polypeptide, suggest that activation of the Nogo-A pathway suppresses axonal growth and dendrite formation in the tested cell line. We found that application of anti-Nogo-A monoclonal antibody can significantly enhance the neuronal maturity of PC-12 cells by blocking the Nogo-A inhibitory effects, providing enhanced effects on neural maturity at the molecular level. No adverse effects were observed on cell viability.

Red blood cells affect the margination of microparticles in synthetic microcapillaries and intravital microcirculation as a function of their size and shape

A key step in particle-based drug delivery throughmicrocirculation is particlemigration from blood flow to vesselwalls, also known as “margination”,which promotes particle contact and adhesion to the vesselwall. Margination and adhesion should be independently addressed as two distinct phenomena, considering that the former is a fundamental prerequisite to achieve particle adhesion and subsequent extravasation. Although margination has beenmodeled by numerical simulations and investigated inmodel systems in vitro, experimental studies including red blood cells (RBCs) are lacking. Here, we evaluate the effect of RBCs on margination through microfluidic studies in vitro and by intravital microscopy in vivo.We showthatmargination,which is almost absent when particles are suspended in a cell-free medium, is drastically enhanced by RBCs. This effect is size- and shape-dependent, larger spherical/discoid particles being more effectively marginated both in vitro and in vivo. Our findings can be explained by the collision of particles with RBCs that induces the drifting of the particles towards the vessel walls where they become trapped in the cell-free layer. These results are relevant for the design of drug delivery strategies based on systemically administered carriers.

Abstract 4536: Biomimetic carriers modulate tumor vascular barrier function

Introduction

We showed that nanoporous silicon (NPS) particles coated with leukocyte cellular membranes -Leukolike Vectors (LLV) - possess cell-like properties. These biomimetic carriers can escape macrophage uptake, delay sequestration by the reticulo-endothelial system, target tumor inflamed vasculature and accumulate within the cancer parenchyma. We characterized the content and function of the leukocyte's proteins transferred onto the LLV coating and evaluated their interaction with inflamed cancer vasculature.

Experimental Procedures

The leukocyte membrane coating was analyzed with several biochemistry techniques. In vitro experiments were performed using reconstructed inflamed endothelia. Flow chamber systems were used to simulate vessel flow dynamics and study LLV docking, firm adhesion and transcytosis. In vivo experiments were performed with Intra Vital Microscopy (IVM) to image in real time LLV behavior in BALB/c mice carrying syngeneic breast cancers.

Results

LLV were studied using dynamic light scattering and scanning electron microscopy to characterize particles size (1 μm), pore sizes (60 nm) and surface properties (positive charge and uniform coating). Biochemical analyses revealed that we successfully transferred on the surface of the LLV critical protein among which LFA-1, MAC1, and CD45. Upon interaction of the LLV with inflamed endothelia we found that VE-cadherin expression was substantially reduced. We also described the differential process of cell internalization and showed that LLV escaped the endo-lysosomal compartment during intracellular trafficking.

IVM showed delayed sequestration by spleen and liver macrophages, increased circulation half-life and increased targeting of tumor associated inflamed vasculature. To further demonstrate the ability of our biomimetic carrier to affect the biology of tumor endothelia, we evaluated the extravasation of an intravascular 70 kDa FITC dextran reporter. We measured the increase in vessel permeability and tissue diffusion over time and confirmed that LLV were able to favor the extravasation of the reporter molecule in the cancer parenchyma.

Conclusion

Our work showed for the first time that is possible to transfer biologically active leukocyte membrane proteins onto synthetic particles. Our biomimetic carriers retain favorable cell-like functions that can enhance the kinetics of oncotransport by decreasing endothelial cellular junctions and increasing diffusion of a therapeutic payload within the tumor tissue. We envision that biomimetic drug delivery systems derived from the infiltrating immune cells of a cancer patient could represent the next generation of personalized treatments.

Note: This abstract was not presented at the meeting.

Citation Format: Alessandro Parodi, Roberto Palomba, Michael Evangelopoulos, Claudia Corbo, Ennio Tasciotti. Biomimetic carriers modulate tumor vascular barrier function. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4536. doi:10.1158/1538-7445.AM2015-4536

Enabling cytoplasmic delivery and organelle targeting by surface modification of nanocarriers

Nanocarriers are designed to specifically accumulate in diseased tissues. In this context, targeting of intracellular compartments was shown to enhance the efficacy of many drugs and to offer new and more effective therapeutic approaches. This is especially true for therapies based on biologicals that must be encapsulated to favor cell internalization, and to avoid intracellular endosomal sequestration and degradation of the payload. In this review, we discuss specific surface modifications designed to achieve cell cytoplasm delivery and to improve targeting of major organelles; we also discuss the therapeutic applications of these approaches. Last, we describe some integrated strategies designed to sequentially overcome the biological barriers that separate the site of administration from the cell cytoplasm, which is the drug's site of action.

[Topical pharmacologic approach with 5% lidocaine medicated plaster in the treatment of localized neuropathic pain]

The treatment of neuropathic pain is a medical challenge. The responsiveness to the different classes of drugs is often unsatisfactory and frequently associated to a wide range of side effects. International guidelines suggest for the "localized" neuropathic pain the topical treatment with 5% lidocaine medicated plaster, alone or associated to systemic drugs, as the first choice since its favorable efficacy and tolerability profile. Many clinical experiences support the rationale for using 5% lidocaine medicated plaster in different kinds of localized neuropathic pain, such as postherpetic and trigeminal neuralgia, compressive syndromes, painful diabetic polyneuropathy and pain secondary to trauma or surgical interventions. This paper reports a series of clinical cases whose heterogeneity suggests the wide burden of applicability of the topical 5% lidocaine, either alone and associated to systemic drugs. All the described conditions were characterized by a highly intense pain, not adequately controlled by actual medications, which improved after the use of topical lidocaine. The good response to lidocaine allowed the reduction, of even the withdrawal, of concurrent drugs and improved the patients' quality of life.

Bromelain surface modification increases the diffusion of silica nanoparticles in the tumor extracellular matrix

Tumor extracellular matrix (ECM) represents a major obstacle to the diffusion of therapeutics and drug delivery systems in cancer parenchyma. This biological barrier limits the efficacy of promising therapeutic approaches including the delivery of siRNA or agents intended for thermoablation. After extravasation due to the enhanced penetration and retention effect of tumor vasculature, typical nanotherapeutics are unable to reach the nonvascularized and anoxic regions deep within cancer parenchyma. Here, we developed a simple method to provide mesoporous silica nanoparticles (MSN) with a proteolytic surface. To this extent, we chose to conjugate MSN to Bromelain (Br-MSN), a crude enzymatic complex, purified from pineapple stems, that belongs to the peptidase papain family. This surface modification increased particle uptake in endothelial, macrophage, and cancer cell lines with minimal impact on cellular viability. Most importantly Br-MSN showed an increased ability to digest and diffuse in tumor ECM in vitro and in vivo.

Structural changes induced in proteins by therapeutic ultrasounds

The structural effect induced by therapeutic ultrasound on proteins in aqueous solution has been investigated with FTIR spectroscopy, UV-VIS spectroscopy, circular dichroism and light scattering. Six proteins (cytochrome, lysozyme, myoglobin, bovine serum albumin, trypsinogen, and alpha-chymotrypsinogen A) with different molecular weight and secondary structure have been studied. The experiment has been performed using an ultrasound source at resonant frequency of 1 MHz and sonication times of 10, 20, 30, 40, 50, and 60 min. A different behaviour of proteins under sonication depends on the dominant secondary structure type (alpha-helix or beta-sheets) and on the grade of the ordered structure. The results suggest that the free radicals, produced by water sonolysis, have an important role in the changes of structural order.

MDCT findings of intestinal ischemia due to midgut torsion without small bowel obstruction in a 12-year-old boy

Intestinal ischemia in the pediatric age group is a rare occurrence. We describe a case of MDCT findings of ischemia due to midgut torsion without intestinal obstruction in a 12-year-old boy, successfully submitted to surgery without any intestinal resection required.

Comparative FISH-mapping of the prion protein gene (PRNP) on cattle, river buffalo, sheep and goat chromosomes

Comparative FISH-mapping of the prion protein gene (PRNP) was performed on cattle (BTA), river buffalo (BBU), sheep (OAR) and goat (CHI) chromosomes using a PCR-product as a probe and R-banding. PRNP was mapped to BTA13q17, BBU14q15, OAR13q15 and CHI13q15 according to standard nomenclatures. These chromosomes and bands were homoeologous among the four species, confirming the high degree of gene and chromosome banding conservation among bovids. Furthermore, the assignment of PRNP to river buffalo and goat chromosomes allowed us to indirectly assign the bovine syntenic group U11 to specific chromosomes, since it is the first in situ localization on BBU14 and CHI13.

[The utility of bispectral index monitoring in general anesthesia]

BACKGROUND

The Bispectral Index (BIS), a parameter derived from the electroencephalograph, has been shown to correlate with increasing sedation and loss of consciousness. This study was designed to investigate whether using BIS would improve anaesthetic drug management and immediate recovery after anaesthesia.

METHODS

160 patients undergoing abdominal surgery were studied. The patients were randomised to receive either propofol or sevoflurane anaesthesia. In each group 40 patients were anaesthetised with BIS monitoring and 40 without BIS. In BIS groups, propofol and sevoflurane dose was adjusted to achieve a target BIS values between 40-60 during the whole procedure. Drug consumption, intraoperative responses, times of recovery after anaesthesia and a "Clinical Quality Scale of Recovery" score were recorded from blinded observators.

RESULTS

Demographic data were similar between groups. BIS monitoring improved the immediate recovery after propofol anaesthesia, while no significant differences were observed in patients receiving sevoflurane. The consumption of both propofol and sevoflurane significantly decreased (30 and 40%, respectively). There was no significant differences in the incidence of intraoperative responses between groups. The BIS groups had a higher percentage of patients with better ICU assessments.

CONCLUSIONS

BIS monitoring decreased the consumption of both propofol and sevoflurane and facilitated the immediate recovery after propofol anaesthesia. Intraoperative course was not changed. These findings indicate that the use of BIS may be a valuable guide of the intraoperatively administration of propofol and sevoflurane.

Effectiveness and safety of combined epidural and general anesthesia for laparoscopic cholecystectomy

BACKGROUND AND OBJECTIVES

The aim of this study was to compare the efficacy and safety of two anesthesia techniques, combined epidural/general anesthesia (CEGA) versus total intravenous anesthesia (TIVA), for laparoscopic cholecystectomy.

METHODS

Forty patients were randomly assigned to one of two different groups: group A received TIVA and group B received CEGA. At preset times during the operation, systolic and diastolic arterial pressure, heart rate, oxygen saturation (SaO2) and end-tidal carbon dioxide (Etco2) were monitored. Postoperatively, recovery (Steward's test) and analgesia (visual analog scale [VAS] pain scores) were assessed, as well as the incidence of adverse effects.

RESULTS

The groups were comparable as to demographic data and duration of surgery and of anesthesia. Intraoperative parameters also showed no statistical differences. Both groups had a rapid recovery (Steward score of 6 within 12 minutes), but group B showed better recovery scores at 4 minutes. Postoperative pain was well controlled in both groups, but group B exhibited better scores at postoperative hour 2. The incidence of postoperative side effects was low in both groups.

CONCLUSIONS

The use of CEGA for laparoscopic cholecystectomy seems to be effective and safe and to offer some advantages as compared to TIVA alone. CEGA can control pain due to CO2-induced peritoneal irritation, providing excellent intra- and postoperative analgesia. CEGA does not require the use of intraoperative intravenous opioids and shortens recovery time, without increasing the incidence of side effects.

[Comparison between balanced anesthesia and total intravenous anesthesia in videolaparocholecystectomy]

The aim of this work was to assess which anaesthetic technique is more suitable to the performance of videolaparocholecystectomy (VLC), particularly seeking for a faster and more comfortable recovery, although saving the maximum safety of the patient. A comparative investigation between two different anaesthetic techniques was carried out in 40 patients scheduled for VLC; the procedure's average length was 110.3 +/- 32.8 minutes and pneu- moperitoneum was obtained with 12-15 mmHg of CO2. Patients (32 females and 8 males, average age 52.3 +/- 8 years and ASA class 1, 2, 3, were randomized in two groups. The first group was administered total intravenous anaesthesia (TIVA): propofol+ fentanyl+pancuronio bromide; the second one received balanced narcosis:TPS+ Isoflurane+Pancuronio bromide. The following parameters were monitored at set times: SAP, DAP, HR and EtCO2; statistical analysis was performed by analysis of variance. The quality of recovery was assessed by Steward's test and analyzed by Student's "t" test. The data obtained from analysis of the intraoperative parameters showed no significant differences between the two groups; on the contrary a statistically significant difference was found with regard to the quality of recovery (p > 0.5 at 5' from the extubation). Thus, the comparative study showed the efficacy and safety of both techniques, but TIVA allowed a faster and more comfortable awakening with shorter time to recovery of consciousness. This, together with the reduced requirements of analgesic drugs in the postoperative period and the lack of air pollution, seems to suggest that TIVA is to be preferred for laparoscopic surgery.

Expression of the human apolipoprotein AI gene fused to the E. coli gene for beta-galactosidase

The human apoAI gene was expressed in E. coli by in-frame fusion to a modified beta-galactosidase gene present in plasmid pUR291. The fused beta-galactosidase-apoAI gene product was expressed at a high level and was recognized by an anti-human apoAI antiserum. Besides the fused protein, at least one degradation product having an Mr similar to that of beta-galactosidase was present in high amounts in bacterial extracts. These results and those of a pulse-chase experiment indicate that degradation took place only in the apoAI moiety of the chimeric protein.

The precursor of mitochondrial pig heart aspartate aminotransferase: preliminary sequence data

The precursor of mitochondrial aspartate aminotransferase from pig heart was synthesized in vitro, purified by immunoprecipitation and partially sequenced. The precursor is 24 amino acid residues longer than the mature protein. Methionine, leucine and isoleucine positions on the peptide extension were assigned.

[Intestinal obstruction and incomplete obstruction from mesenteric cyst formation in children (author's transl)]

In the light of three cases of their own observation, of children with mesenteric cysts causing complete or incomplete intestinal obstruction, the authors review the existing literature on the subject, discuss the etiology, clinical aspects, and therapeutic methods for the correction of such pathology, and conclude by calling attention to mesenteric cysts as possible causes of intestinal transit disorders in the pediatric age group.

[Current views concerning the etiopathogenesis of reflux esophagitis in children]

Esophagitis is caused by a gastro-esophageal reflux sometimes reflecting anatomical inadequacy of structures that secure the relationships between the cardia and the diaphragm, fundus of the stomach, and other surrounding viscera, but more often due to functional deficiency of lower esophageal sphincter (LES), this representing the main factor for maintenance of the mechanism of cardial continence. Manometric studies of intraluminal pressures in the esophagus have revealed the presence of a high-pressure segment in the distal esophagus, where a mean pressure of 12-13 mm Hg obtains over a length of 3 or 4 cm. In the first two weeks of extrauterine life the LES is between 0.5 and 1 cm long, with a pressure of 3 mm Hg; pressure values in the LES equal adult values at about one month of age, showing that neuromuscular control of the sphincter has been achieved. Gastro-esophageal reflux, however, is very common in the newborn and not enough by itself to cause peptic disease of the esophagus; this requires the concomitance of morphological defects of the esophageal mucosa and/or dynamic-functional disturbances. This, according to the authors, is why esophagitis actually occurs in only about 60% of patients with radiologically and pHmetrically demonstrated gastro-esophageal reflux.

[Current trends in the treatment of reflux esophagitis in childhood]

A problem of some complexity is the management of pathological gastro-esophageal reflux due to the presence of cardio-hiatal malformation, malposition of the cardia and gastric tuberosity, a congenitally short esophagus, and the like. Sometimes, however, there is no demonstrable morphological aleration and the condition, characterized by primitive hypotonia of the LES, goes under the name of infant chalasia of the esophagus. The general policy is to try first a conservative treatment consisting of dietary and postural measures and the administration of metoclopramide and d;ugs that protect the esophageal mucosa; this stage, however, should not be prolonged beyond 6 weeks. The presence of gastro-esophageal reflux associated with hiatal hernia; the presence of severe esophagitis or peptic stenosis of the esophagus and the persistence of symptoms after an adequate period of conservative therapy constitute as many indications for surgical correction. Good results can be obtained by restoring or strengthening the failing function of the LES, as is done quite successfully with funduplication after Nissen or with method of Belsey-Mark IV.

[Clinical picture and diagnosis of reflux esophagitis in children]

Whereas a burning retrosternal pain irradiating upward is the main symptom of reflux esophagitis in the adult, this symptom is usually not extant in children. Rather, the child will show unaccountable vomiting, stunted growth, anemia of unknown etiology, and respiratory disturbances. The pathologic condition more often associated with reflux esophagitis is hypertrophic stenosis of the pylorus, which is in fact regarded as one of the causes of the esophageal disorder. Reflux esophagitis may lead to ulceration and hemorrhage, and may evolve into cicatricial retraction and esophageal stenosis, the latter sometimes quite tight. The condition is diagnosed in light of radiological examination and endoscopy. Whit older children, one may add the Bernstein test and pressure and pH readings. The paper concludes by pointing out the different diagnostic approach in the newborn and small baby on the one hand and in older children on the other.

[Current criteria of treatment of angiomas]

The authors set out their therapeutic trend in the treatment of angioma and the criteria governing the use of the various therapies according to the type of dysplasia and its clinical course; they then report on the results obtained in a series of 400 cases. Only 22 cases with unfavourable trend (evolution of lesion) were observed, whereas the others exhibited spontaneous regression (85 cases), arrest of evolution (50 cases) or regression or cure (243 cases).