25 research outputs found

    Putting a “C60 Ball” and Chain to Chlorin e6 Improves Its Cellular Uptake and Photodynamic Performances

    Get PDF
    Chlorin e6 (Ce6) and fullerene (C60) are among the most used photosensitizers (PSs) for photodynamic therapy (PDT). Through the combination of the chemical and photophysical properties of Ce6 and C60, in principle, we can obtain an “ideal” photosensitizer that is able to bypass the limitations of the two molecules alone, i.e., the low cellular uptake of Ce6 and the scarce solubility and absorption in the red region of the C60. Here, we synthesized and characterized a Ce6–C60 dyad. The UV-Vis spectrum of the dyad showed the typical absorption bands of both fullerene and Ce6, while a quenching of Ce6 fluorescence was observed. This behavior is typical in the formation of a fullerene–antenna system and is due to the intramolecular energy, or electron transfer from the antenna (Ce6) to the fullerene. Consequently, the Ce6–C60 dyad showed an enhancement in the generation of reactive oxygen species (ROS). Flow cytometry measurements demonstrated how the uptake of the Ce6 was strongly improved by the conjugation with C60. The Ce6–C60 dyad exhibited in A431 cancer cells low dark toxicity and a higher PDT efficacy than Ce6 alone, due to the enhancement of the uptake and the improvement of ROS generation

    Light-Enhanced Cytotoxicity of Doxorubicin by Photoactivation

    Get PDF
    The combination of photodynamic therapy with chemotherapy (photochemotherapy, PCT) can lead to additive or synergistic antitumor effects. Usually, two different molecules, a photosensitizer (PS) and a chemotherapeutic drug are used in PCT. Doxorubicin is one of the most successful chemotherapy drugs. Despite its high efficacy, two factors limit its clinical use: severe side effects and the development of chemoresistance. Doxorubicin is a chromophore, able to absorb light in the visible range, making it a potential PS. Here, we exploited the intrinsic photosensitizing properties of doxorubicin to enhance its anticancer activity in leukemia, breast, and epidermoid carcinoma cells, upon irradiation. Light can selectively trigger the local generation of reactive oxygen species (ROS), following photophysical pathways. Doxorubicin showed a concentration-dependent ability to generate peroxides and singlet oxygen upon irradiation. The underlying mechanisms leading to the increase in its cytotoxic activity were intracellular ROS generation and the induction of necrotic cell death. The nuclear localization of doxorubicin represents an added value for its use as a PS. The use of doxorubicin in PCT, simultaneously acting as a chemotherapeutic agent and a PS, may allow (i) an increase in the anticancer effects of the drug, and (ii) a decrease in its dose, and thus, its dose-related adverse effects

    Frequency of left ventricular hypertrophy in non-valvular atrial fibrillation

    Get PDF
    Left ventricular hypertrophy (LVH) is significantly related to adverse clinical outcomes in patients at high risk of cardiovascular events. In patients with atrial fibrillation (AF), data on LVH, that is, prevalence and determinants, are inconsistent mainly because of different definitions and heterogeneity of study populations. We determined echocardiographic-based LVH prevalence and clinical factors independently associated with its development in a prospective cohort of patients with non-valvular (NV) AF. From the "Atrial Fibrillation Registry for Ankle-brachial Index Prevalence Assessment: Collaborative Italian Study" (ARAPACIS) population, 1,184 patients with NVAF (mean age 72 \ub1 11 years; 56% men) with complete data to define LVH were selected. ARAPACIS is a multicenter, observational, prospective, longitudinal on-going study designed to estimate prevalence of peripheral artery disease in patients with NVAF. We found a high prevalence of LVH (52%) in patients with NVAF. Compared to those without LVH, patients with AF with LVH were older and had a higher prevalence of hypertension, diabetes, and previous myocardial infarction (MI). A higher prevalence of ankle-brachial index 640.90 was seen in patients with LVH (22 vs 17%, p = 0.0392). Patients with LVH were at significantly higher thromboembolic risk, with CHA2DS2-VASc 652 seen in 93% of LVH and in 73% of patients without LVH (p <0.05). Women with LVH had a higher prevalence of concentric hypertrophy than men (46% vs 29%, p = 0.0003). Logistic regression analysis demonstrated that female gender (odds ratio [OR] 2.80, p <0.0001), age (OR 1.03 per year, p <0.001), hypertension (OR 2.30, p <0.001), diabetes (OR 1.62, p = 0.004), and previous MI (OR 1.96, p = 0.001) were independently associated with LVH. In conclusion, patients with NVAF have a high prevalence of LVH, which is related to female gender, older age, hypertension, and previous MI. These patients are at high thromboembolic risk and deserve a holistic approach to cardiovascular prevention

    Gender differences in cardiovascular prophylaxis: Focus on antiplatelet treatment

    Get PDF
    Cardiovascular disease (CVD) represents the leading cause of death worldwide, and equally affects both sexes although women develop disease at an older age than men. A number of clinical evidence has identified the female sex as an independent factor for poor prognosis, with the rate of mortality and disability following an acute cardiovascular (CV) event being higher in women than men. It has been argued that the different level of platelet reactivity between sexes may account for a different responsiveness to anti-platelet therapy, with consequent important implications on clinical outcomes. However, conclusive evidence supporting the concept of a gender-dependent effectiveness of platelet inhibitors are lacking. On the contrary, sex-related dissimilarities have been evidenced in cardiovascular patients in terms of age of presentation, comorbidities such as obesity, diabetes and renal disease, and a different pharmacological approach to and effectiveness in controlling classical cardiovascular risk factors such as hypertension, glucose profile and lipid dysmetabolism. All these factors could place women at an increased level of cardiovascular risk compared to men, and may concur to an enhanced pro-thrombogenic profile. The purpose of this manuscript is to provide an overview of gender-related differences in cardiovascular treatment, in order to highlight the need to improve the pharmacological prophylaxis adopted in women through a more accurate evaluation of the overall cardiovascular risk profile with consequent establishment of a more effective and targeted anti-thrombotic strategy which is not limited to the use of anti-platelet agents

    Concanavalin A-Rose Bengal bioconjugate for targeted Gram-negative antimicrobial photodynamic therapy

    No full text
    Photodynamic therapy (PDT) is considered a very promising therapeutic modality for antimicrobial therapy. Although several studies have demonstrated that Gram-positive bacteria are very sensitive to PDT, Gram-negative bacteria are more resistant to photodynamic action. This difference is due to a different cell wall structure. Gram-negative bacteria have an outer cell membrane containing lipopolysaccharides (LPS) that hinder the binding of photosensitizer molecules, protecting the bacterial cells from chemical attacks. Combination of the lipopolysaccharides-binding activity of Concanavalin A (ConA) with the photodynamic properties of Rose Bengal (RB) holds the potential of an innovative protein platform for targeted photodynamic therapy against Gram-negative bacteria. A ConA-RB bioconjugate was synthesized and characterized. Approximately 2.4 RB molecules were conjugated per ConA monomer. The conjugation of RB to ConA determines a decrease of the singlet oxygen generation and an increase of superoxide and peroxide production. The photokilling efficacy of the ConA-RB bioconjugate was demonstrated in a planktonic culture of E. coli. Irradiation with white light from a LED lamp produced a dose-dependent photokilling of bacteria. ConA-RB conjugates exhibited a consistent improvement over RB (up to 117-fold). The improved uptake of the photosensitizer explains the enhanced PDT effect accompanying increased membrane damages induced by the ConA-RB conjugate. The approach can be readily generalized (i) using different photo/sonosensitizers, (ii) to target other pathogens characterized by cell membranes containing lipopolysaccharides (LPS)

    Isotropic microscale mechanical properties of coral skeletons

    No full text
    Scleractinian corals are a major source of biogenic calcium carbonate, yet the relationship between their skeletal microstructure and mechanical properties has been scarcely studied. In this work, the skeletons of two coral species: solitary Balanophyllia europaea and colonial Stylophora pistillata, were investigated by nanoindentation. The hardness HIT and Young\u2019s modulus EIT were determined from the analysis of several load\u2013depth data on two perpendicular sections of the skeletons: longitudinal (parallel to the main growth axis) and transverse. Within the experimental and statistical uncertainty, the average values of the mechanical parameters are independent on the section\u2019s orientation. The hydration state of the skeletons did not affect the mechanical properties. The measured values, EIT in the 76\u201377 GPa range, andHIT in the 4.9\u20135.1 GPa range, are close to the ones expected for polycrystalline pure aragonite. Notably, a small difference in HIT is observed between the species. Different from corals, single-crystal aragonite and the nacreous layer of the seashell Atrina rigida exhibit clearly orientation-dependent mechanical properties. The homogeneous and isotropic mechanical behaviour of the coral skeletons at the microscale is correlated with the microstructure, observed by electron microscopy and atomic force microscopy, and with the X-ray diffraction patterns of the longitudinal and transverse sections

    Erratum to: Medication prescription and adherence disparities in non valvular atrial fibrillation patients: an Italian portrait from the ARAPACIS study (Intern Emerg Med, (2014), 9, (861-870), DOI 10.1007/s11739-014-1096-1)

    No full text
    Non-valvular atrial fibrillation (NVAF) represents a major health-care problem, needing an extensive and strict thrombosis prevention for stroke and cardiovascular (CV) disease risks. NVAF management guidelines recommend adequate antithrombotic and antiatherosclerotic therapies. Medication adherence has been recognized as a pivotal element in health quality promotion and in the achievement of better clinical outcomes. We conducted a post-hoc analysis of the ‘‘Atrial fibrillation Registry for Ankle-brachial index Prevalence Assessment-Collaborative Italian Study (ARAPACIS)’’ with the aim of discerning differences in pharmacological management and medication adherence among NVAF Italian patients. Furthermore, data were analysed according to Italian geographical macro-regions (North, Center, South) to evaluate whether socioeconomic conditions might also influence medication adherence. Thus, we selected 1,366 NVAF patients that fulfilled the Morisky Medication Adherence Scale-4 items. Regional disparities in drug prescriptions were observed. In particular, in high-risk patients (CHA2DS2–VASc C2) oral anticoagulants were more prescribed in Northern and Center patients (61 and 60 %, respectively) compared to 53 % of high-risk Southern patients. Also, medication adherence showed a progressive decrease from North to South (78 vs. 60 %, p\0.001). This disparity was independent of the number of drugs consumed for any reason, since prevalence of poly-therapy among the three macro-regions was similar. Our results show regional differences in NVAF patients’ antithrombotic management and medication adherence, potentially reflecting well-known disparities in socioeconomic status among Italian regions. Future interventions promoting campaigns to global health-care education may be desirable to improve clinical outcomes in NVAF patients

    Correction to Calcite Single Crystals as Hosts for Atomic-Scale Entrapment and Slow Release of Drugs [Adv. Healthcare Mater. 4, (2015), 1510-1516] doi: 10.1002/adhm.201500170

    No full text
    Doxorubicin (DOX)/CaCO 3 single crystals act as pH responsive drug carrier. A biomimetic approach demonstrates that calcite single crystals are able, during their growth in the presence of doxorubicin, to entrap drug molecules inside their lattice along specifi c crystallographic directions. Alterations in lattice dimensions and microstructural parameters are determined by means of high-resolution synchrotron powder diffraction measurements. Confocal microscopy confi rms that doxorubicin is uniformly embedded in the crystal and is not simply adsorbed on the crystal surface. A slow release of DOX was obtained preferentially in the proximity of the crystals, targeting cancer cells

    Medication prescription and adherence disparities in non valvular atrial fibrillation patients: an Italian portrait from the ARAPACIS study.

    No full text
    Non-valvular atrial fibrillation (NVAF) represents a major health-care problem, needing an extensive and strict thrombosis prevention for stroke and cardiovascular (CV) disease risks. NVAF management guidelines recommend adequate antithrombotic and anti-atherosclerotic therapies. Medication adherence has been recognized as a pivotal element in health quality promotion and in the achievement of better clinical outcomes. We conducted a post-hoc analysis of the "Atrial fibrillation Registry for Ankle-brachial index Prevalence Assessment-Collaborative Italian Study (ARAPACIS)" with the aim of discerning differences in pharmacological management and medication adherence among NVAF Italian patients. Furthermore, data were analysed according to Italian geographical macro-regions (North, Center, South) to evaluate whether socioeconomic conditions might also influence medication adherence. Thus, we selected 1,366 NVAF patients that fulfilled the Morisky Medication Adherence Scale-4 items. Regional disparities in drug prescriptions were observed. In particular, in high-risk patients (CHA2DS2-VASc ≄2) oral anticoagulants were more prescribed in Northern and Center patients (61 and 60 %, respectively) compared to 53 % of high-risk Southern patients. Also, medication adherence showed a progressive decrease from North to South (78 vs. 60 %, p < 0.001). This disparity was independent of the number of drugs consumed for any reason, since prevalence of poly-therapy among the three macro-regions was similar. Our results show regional differences in NVAF patients' antithrombotic management and medication adherence, potentially reflecting well-known disparities in socioeconomic status among Italian regions. Future interventions promoting campaigns to global health-care education may be desirable to improve clinical outcomes in NVAF patients
    corecore