Evaluation of nontarget lesions in femoropopliteal disease using near-infrared spectroscopy intravascular ultrasound imaging.

BACKGROUND: In coronary artery disease (CAD), lipid-core-containing plaque (LCP) in nontarget lesions detected using near-infrared spectroscopy intravascular ultrasound (NIRS-IVUS) was related to increased major adverse cardiovascular events in patients with CAD. In the endovascular therapy field, few previous studies using NIRS-IVUS revealed the presence of LCPs in severe stenotic lesions of femoropopliteal disease. AIM: This study aimed to assess the plaque morphology of nontarget lesions, especially LCPs, and compare it with that of target lesions using NIRS-IVUS in patients with femoropopliteal disease. METHODS: This single-center prospective observational study included 14 patients who underwent endovascular therapy for FP disease. NIRS-IVUS assessment was performed on the entire FP arterial segment. Forty-one LCP lesions with a maximum lipid-core burden index in any 4-mm region (max LCBI4mm) > 100 were detected using NIRS-IVUS. We evaluated the patient and lesion characteristics. LCP lesions were divided into the target (n = 18) and nontarget (n = 23) lesion groups for comparison. RESULTS: Patient characteristics were notable for advanced age (76.8 ± 6.6 years); high proportion of males (78.7%); and high incidence of hypertension (100%), dyslipidemia (78.6%), diabetes (64.3%). Regarding NIRS findings, the target lesion group exhibited a significantly smaller proportion of LCPs concerning the lesion length (25.9 ± 15.7% vs. 50.6 ± 29.2%, p = 0.002) than the nontarget lesion group. Conversely, there were no significant differences in the value of max LCBI4mm (284.4 ± 153.4 vs. 289.5 ± 113.1, p = 0.90), length of LCP lesion (9.8 ± 9.7 mm vs. 10.7 ± 6.9 mm, p = 0.74), and distribution of LCPs (p = 0.08) between the groups. In addition, the number of LCPs in the target FP artery positively correlated with max LCBI4mm in the target FP artery (r = 0.671, p = 0.008). CONCLUSIONS: NIRS-IVUS findings demonstrated the presence of LCPs in nontarget lesions in patients with FP disease. Moreover, the abundance of LCPs in nontarget lesions was similar to that in target lesions in FP disease.

Analysis of carotid vulnerable plaque MRI high-risk features and clinical risk factors associated with concomitant acute cerebral infarction.

BACKGROUND: This study aimed to investigate the correlation between the high-risk characteristics of high-resolution MRI carotid vulnerable plaques and the clinical risk factors and concomitant acute cerebral infarction (ACI). METHODS: Forty-five patients diagnosed with a single vulnerable carotid plaque by MRI were divided into two groups based on whether they had ipsilateral ACI. The clinical risk factors and the observation values or frequency of occurrence of high-risk MRI phenotypes of plaque volume, LRNC, IPH and ulcer were statistically compared between the two groups. RESULTS: A total of 45 vulnerable carotid artery plaques were found in 45 patients, 23 patients with ACI and 22 patients without ACI. There were no significant differences in age, sex, smoking, serum TC, TG and LDL between the two groups (all P > 0.05), but the ACI group had significantly more patients with hypertension (P < 0.05) and the without ACI group coronary heart disease (P < 0.05). The volume of vulnerable carotid plaque in the group with ACI (1004.19 ± 663.57 mm3) was significantly larger than that in the group without ACI (487.21 ± 238.64 mm3) (P < 0.05). The phenotype of vulnerable carotid artery plaque was 13 cases of LRNC, 8 cases of LRNC + IPH, 5 cases of LRNC + Ulcer, and 19 cases of LRNC + IPH + Ulcer. There was no significant difference in this distribution between the two groups (all P > 0.05) with the exception of LRNC + IPH + Ulcer. The 14 cases of LRNC + IPH + LRNC + IPH + Ulcer (60.87%) in the group with ACI and was significantly greater than the 5 (22.73%) in patients without ACI (P < 0.05). CONCLUSION: It is preliminarily thought that hypertension is the main clinical risk factor for vulnerable carotid plaques with ACI and the combination of plaque volume with vulnerable carotid plaque and LRNC + IPH + Ulcer is a high-risk factor for complicated ACI. It has high clinical therapeutic value due to the accurate diagnosis of responsible vessels and plaques with high-resolution MRI.

The Anti-Arthritic Activity of Diclofenac Lipid-Core Nanocapsules: Stereological Analysis Showing More Protection of Deep Joint Components.

Diclofenac is the most prescribed nonsteroidal anti-inflammatory drug worldwide and is used to relieve pain and inflammation in inflammatory arthritis. Diclofenac is associated with serious adverse effects, even in regular-dose regimens. Drug delivery systems can overcome this issue by reducing adverse effects and optimizing their efficacy. This study evaluated the activity of lipid-core nanocapsules loaded with diclofenac (DIC-LNCs) in an experimental model of adjuvant-induced arthritis. The diclofenac nanoformulation was obtained via self-assembly. A stereological analysis approach was applied for the morphological quantification of the volume, density, and cellular profile count of the metatarsophalangeal joints of rats. Proinflammatory cytokines and biochemical profiles were also obtained. Our results showed that the diclofenac nanocapsule DIC-LNCs were able to reduce arthritis compared with the control group and the DIC group. DIC-LNCs efficiently reduced proinflammatory cytokines, C-reactive protein, and xanthine oxidase levels. Additionally, DIC-LNCs reduced the loss of synoviocytes and chondrocytes compared with the DIC (p < 0.05) and control groups (p < 0.05). These data suggest that DIC-LNCs have anti-arthritic activity and preserve joint components, making them promising for clinical use.

Evaluation of an Efficient and Skin-Adherent Semisolid Sunscreen Nanoformulation.

INTRODUCTION: Sunscreens are substances applied on the skin surface to protect the skin from the harmful effects of UV light. Nanoparticles can increase the retention time of the sunscreen on the skin surface and its efficacy, by acting as physical barriers. The present investigation aimed to evaluate the influence of the chitosan coating of benzophenone-3-loaded lipid-core nanocapsules (CH-LCN) on the skin adhesion and photoprotective effect of the sunscreen. METHODS: CH-LNC were obtained by the interfacial deposition of preformed polymer. A suitable semisolid formulation was obtained by using hydroxyethyl cellulose as the gel-forming polymer. Skin adhesion experiments were performed in vitro by applying the formulation on porcine skin and keeping it under water at 32 °C for up to 60 min. Photoprotective effect was analyzed in vitro by the capacity of the formulations to protect a photo unstable substance (resveratrol) from degradation under UV light. RESULTS: CH-LNC presented size of around 150 nm, with low polydispersity, positive zeta potential, due to chitosan, and benzophenone-3 encapsulation efficiency of close to 100% (3 mg/mL). The proposed gel presented suitable consistence and pH for skin application and benzophenone-3 concentration of around 3 mg/g. Although coated and uncoated lipid-core nanocapsules increased benzophenone-3 skin adhesion after 10 min of water immersion, only the nanoparticles coated with chitosan were able to do so after 60 min. The chitosan coating of the nanocapsules increased the photoprotection of the sunscreen under UVA and UVB light after 60 min of exposure, probably due to the film-forming properties of chitosan. CONCLUSION: The chitosan coating of CH-LCN increased the skin adhesion and the photoprotective effect of the sunscreen.

Artemether-loaded polymeric lipid-core nanocapsules reduce cell viability and alter the antioxidant status of U-87 MG cells.

Glioblastomas are tumors that present a high mortality rate. Artemether (ART) is a lactone with antitumor properties, demonstrating low bioavailability and water solubility. In the present study, we developed lipid-core nanocapsules (LNC) containing pequi oil (Caryocar brasiliense Cambess) as the oily core for ART-loaded LNCs (LNCART) and evaluated their effect on human glioblastoma cells (U-87 MG). LNCs were developed by interfacial deposition of a preformed polymer, followed by physicochemical characterization. LNCART revealed a diameter of 0.216 µm, polydispersity index of 0.161, zeta potential of -12.0 mV, and a pH of 5.53. Furthermore, mitochondrial viability, proliferation, total antioxidant status, and antioxidant enzyme activity were evaluated. ART reduced cell viability after 24 h and proliferation after 48 h of treatment at concentrations equal to or above 40 µg . mL-1. LNCART, at 1.25 µg . mL-1, reduced these parameters after 24 h of treatment. Furthermore, superoxide dismutase (SOD) activity was elevated, while glutathione reductase (GR) activity was reduced. These findings suggest that ART loaded into LNC may be a promising alternative to improve its pharmacological action and possible application as a therapeutic agent for glioblastoma.

Lipid Core Burden Index Assessed by Near-Infrared Spectroscopy of Symptomatic Carotid Plaques: Association with Magnetic Resonance T1-Weighted Imaging.

INTRODUCTION: Vulnerable plaques are a strong predictor of cerebrovascular ischemic events, and high lipid core plaques (LCPs) are associated with an increased risk of embolic infarcts during carotid artery stenting (CAS). Recent developments in magnetic resonance (MR) plaque imaging have enabled noninvasive assessment of carotid plaque vulnerability, and the lipid component and intraplaque hemorrhage (IPH) are visible as high signal intensity areas on T1-weighted MR images. Recently, catheter-based near-infrared spectroscopy (NIRS) has been shown to accurately distinguish LCPs without IPH. This study aimed to determine whether the results of assessment of high LCPs by catheter-based NIRS correlate with the results of MR plaque imaging. METHODS: We recruited 82 consecutive symptomatic carotid artery stenosis patients who were treated with CAS under NIRS and MR plaque assessment. Maximum lipid core burden index (max-LCBI) at minimal luminal areas (MLA), defined as max-LCBIMLA, and max-LCBI for any 4-mm segment in a target lesion, defined as max-LCBIAREA, were assessed by NIRS. Correlations were investigated between max-LCBI and MR T1-weighted plaque signal intensity ratio (T1W-SIR) and MR time-of-flight signal intensity ratio (TOF-SIR) in the same regions as assessed by NIRS. RESULTS: Both T1W-SIRMLA and T1W-SIRAREA were significantly lower in the high LCP group (max-LCBI >504, p < 0.001 for both), while TOF-SIRMLA and TOF-SIRAREA were significantly higher in the high LCP group (p < 0.001 and p = 0.004, respectively). A significant linear correlation was present between max-LCBIMLA and both TIW-SIRMLA and TOF-SIRMLA (r = -0.610 and 0.452, respectively, p < 0.0001 for both). Furthermore, logistic regression analysis revealed that T1W-SIRMLA and TOF-SIRMLA were significantly associated with a high LCP assessed by NIRS (OR, 44.19 and 0.43; 95% CI: 6.55-298.19 and 0.19-0.96; p < 0.001 and = 0.039, respectively). CONCLUSIONS: A high LCP assessed by NIRS correlates with the signal intensity ratio of MR imaging in symptomatic patients with unstable carotid plaques.

Folic Acid-Doxorubicin-Double-Functionalized-Lipid-Core Nanocapsules: Synthesis, Chemical Structure Elucidation, and Cytotoxicity Evaluation on Ovarian (OVCAR-3) and Bladder (T24) Cancer Cell Lines.

PURPOSE: Folic acid-doxorubicin-double-functionalized-lipid-core nanocapsules (LNC-CS-L-Zn+2-DOX-FA) were prepared, characterized, and evaluated in vitro against ovarian and bladder cancer cell lines (OVCAR-3 and T24). METHODS: LNC-CS-L-Zn+2-DOX-FA was prepared by self-assembly and interfacial reactions, and characterized using liquid chromatography, particle sizing, transmission electron microscopy, and infrared spectroscopy. Cell viability and cellular uptake were studied using MTT assay and confocal microscopy. RESULTS: The presence of lecithin allows the formation of nanocapsules with a lower tendency of agglomeration, narrower size distributions, and smaller diameters due to an increase in hydrogen bonds at the surface. LNC-L-CS-Zn+2-DOX-FA, containing 98.00 ± 2.34 µg mL-1 of DOX and 105.00 ± 2.05 µg mL-1 of FA, had a mean diameter of 123 ± 4 nm and zeta potential of +12.0 ± 1.3 mV. After treatment with LNC-L-CS-Zn+2-DOX-FA (15 µmol L-1 of DOX), T24 cells had inhibition rates above 80% (24 h) and 90% (48 h), whereas OVCAR-3 cells showed inhibition rates of 68% (24 h) and 93% (48 h), showing higher cytotoxicity than DOX.HCl. The fluorescent-labeled formulation showed a higher capacity of internalization in OVCAR-3 compared to T24 cancer cells. CONCLUSION: Lecithin favored the increase of hydrogen bonds at the surface, leading to a lower tendency of agglomeration for nanocapsules. LNC-CS-L-Zn+2-DOX-FA is a promising therapeutic agent against tumor-overexpressing folate receptors.

Small lipid core burden index in patients with stable angina pectoris is also associated with microvascular dysfunction: Insights from intracoronary electrocardiogram.

Near-infrared spectroscopy with intravascular ultrasound (NIRS)-IVUS enables precise detection of lipid core burden. Intracoronary electrocardiography (ECG) can detect slight ischemia during percutaneous coronary intervention (PCI), indicating microvascular dysfunction (MD) by distal embolization, etc. Thus, this study aimed to investigate whether plaques with a low max-lipid core burden index (LCBI) at 4 mm (LCBI4mm) influence MD, using intracoronary ECG. We enrolled 40 consecutive patients who underwent PCI for stable angina pectoris (SAP) due to stenosis of the proximal segment of the left anterior descending artery in this study. Max-LCBI4mm was measured for each culprit lesion. Gray-scale IVUS data including plaque burden were measured. Intracoronary ECG was performed to measure the time from the initiation of ST-segment elevation from the isoelectric baseline after stent balloon inflation to the return of the ST-segment to the isoelectric baseline after the deflation of the stent balloon, which was defined as the severity of the MD. The patients were divided into two groups according to median max-LCBI4mm of 120 as follows: low- [n = 20] and high- [n = 20] LCBI groups. The overall mean Max-LCBI4mm was 120 ± 86. No differences in baseline characteristics, including prevalence of dyslipidemia, were found between both groups, as well as in the gray-scale IVUS parameters. The severity of the MD was greater in the high-LCBI group than in the low-LCBI group (16.6 ± 9.1 vs 4.7 ± 4.8 s, P < 0.01). The no-reflow and slow-flow phenomena were not observed. Even max-LCBI4mm value <400 on NIRS-IVUS was associated with MD during PCI in patients with SAP.

Red and White Thrombus Characteristics in Patients Undergoing Carotid Endarterectomy.

OBJECTIVE: The study aimed to compare the characteristics of red and white thrombi in patients undergoing carotid endarterectomy. MATERIAL AND METHODS: The study was conducted in 81 patients with ischemic stroke who underwent carotid endarterectomy for carotid artery stenosis. Carotid plaques were graded by two pathologists. Thrombus materials were divided into two groups: white and red. The parameters of assessment were plaque rupture, lipid core, fibrous cap thickness, inflammation, intraplaque hemorrhage, calcification, necrotic core, and neovascularization. Normally distributed data were evaluated using Mann-Whitney U and Chi-squared tests. RESULTS: The ratio of white and red thrombus was 19.8% and 80.2%, respectively. Lipid core, plaque rupture, necrotic core, neovascularization, intraplaque hemorrhage, obstruction, and inflammation were observed more in red thrombus, which were statistically significant. Calcification and fibrous cap thickness were not statistically significant in the two groups. Moreover, intimal smooth muscle cells were present in all thrombus types. CONCLUSION: In our study, we found that red thrombi had more unstable characteristics than white thrombi. Thus, the risk for ischemic cerebrovascular events is more in red thrombi. However, this finding cannot be generalized due to the small number of patients in this study. Therefore, studies involving more patients are needed.

Chitosan-Coated Lipid-Core Nanocapsules Functionalized with Gold-III and Bevacizumab Induced In Vitro Cytotoxicity against C6 Cell Line and In Vivo Potent Antiangiogenic Activity.

PURPOSE: Bevacizumab (BCZ) is a recombinant monoclonal antibody that inhibits the biological activity of the vascular endothelial growth factor, which has an important role in angiogenesis for tumoral growth and progression. In this way, our objective was to develop chitosan-coated lipid-core nanocapsules functionalized with BCZ by an organometallic complex using gold-III. METHODS: The formulation was produced and characterized in relation to physicochemical characteristics. Furthermore, the antitumoral and antiangiogenic activities were evaluated against C6 glioma cell line and chicken embryo chorioallantoic membrane (CAM), respectively. RESULTS: Final formulation showed nanometric size, narrow polydispersity, positive zeta potential and gold clusters size lower than 2 nm. BCZ in aqueous solution (0.01-0.10 µmol L-1) did not show cytotoxic activity in vitro against C6 glioma cell line; although, MLNC-Au-BCZ showed cytotoxicity with a median inhibition concentration of 30 nmol L-1 of BCZ. Moreover, MLNC-Au-BCZ demonstrated cellular internalization dependent on incubation time and BCZ concentration. BCZ solution did not induce significant apoptosis as compared to MLNC-Au-BCZ within 24 h of treatment. CAM assay evidenced potent antiangiogenic activity for MLNC-Au-BCZ, representing a decrease of 5.6 times in BCZ dose comparing to BCZ solution. CONCLUSION: MLNC-Au-BCZ is a promising product for the treatment of solid tumors.

Encapsulation in lipid-core nanocapsules improves topical treatment with the potent antileishmanial compound CH8.

Cutaneous leishmaniasis (CL) is a neglected parasitic disease conventionally treated by multiple injections with systemically toxic drugs. Aiming at a more acceptable therapy, we developed lipid-core nanocapsules (LNCs) entrapping the potent antileishmanial chalcone (CH8) for topical application. Rhodamine-labeled LNC (Rho-LNC-CH8) was produced for imaging studies. LNC-CH8 and Rho-LNC-CH8 had narrow size distributions (polydispersity index <0.10), with similar mean sizes (~180 nm) by dynamic light scattering. In vitro, Rho-LNC-CH8 was rapidly internalized by extracellular Leishmania amazonensis parasites macrophages in less than 15 min. LNC-CH8 activated macrophage oxidative mechanisms more efficiently than CH8, and was more selectively toxic against the intracellular parasites. In vivo, topically applied Rho-LNC-CH8 efficiently permeated mouse skin. In L. amazonensis-infected mice, LNC-CH8 reduced the parasite load by 86% after three weeks of daily topical treatment, while free CH8 was ineffective. In conclusion, LNC-CH8 has strong potential as a novel topical formulation for CL treatment.

Near-infrared spectroscopy-derived lipid core burden index predicts adverse cardiovascular outcome in patients with coronary artery disease during long-term follow-up.

Aims: Near-infrared spectroscopy (NIRS) is able to quantify cholesterol within coronary arteries by the lipid core burden index (LCBI). We studied the prognostic value of NIRS-derived LCBI in patients with coronary artery disease (CAD) for adverse cardiac outcome during long-term follow-up. Methods and results: During 2009-2013, NIRS was performed in a non-culprit artery of 275 patients undergoing coronary angiography for acute coronary syndrome (ACS) or stable angina. LCBI was quantified by an independent corelab for the region of interest (LCBIROI) and the 4 and 10 mm long segment with the maximum LCBI (MaxLCBI4mm and MaxLCBI10mm). The primary endpoint was major adverse cardiac events (MACE), defined as the composite of all-cause death, non-fatal ACS, or unplanned revascularization. Hazard ratios (HR) were adjusted for age, gender, clinical risk factors, and segment plaque burden based on intravascular ultrasound. During a median follow-up of 4.1 years, 79 patients (28.7%) had MACE. There was a statistically significant and independent continuous relationship between higher MaxLCBI4mm values and a higher risk of MACE. Each 100 units increase of MaxLCBI4mm was associated with a 19% increase in MACE [hazard ratios (HR) 1.19, 95% confidence intervals (95% CI): 1.07-1.32, P = 0.001]. Continuous MaxLCBI4mm remained independently associated with MACE after exclusion of target lesion-related events (HR 1.21, 95% CI: 1.08-1.35), as well as after exclusion of adverse events related to the NIRS-imaged coronary segment (HR 1.19, 95% CI: 1.06-1.34). Results for MaxLCBI10mm were comparable. Conclusion: NIRS-derived LCBI is associated with adverse cardiac outcome in CAD patients during long-term follow-up independent of clinical risk factors and plaque burden.

Effects of Fish and Grape Seed Oils as Core of Haloperidol-Loaded Nanocapsules on Oral Dyskinesia in Rats.

Haloperidol is a widely used antipsychotic, despite the severe motor side effects associated with its chronic use. This study was carried out to compare oral dyskinesia induced by different formulations of haloperidol-loaded nanocapsules containing caprylic/capric triglycerides, fish oil or grape seed oil (GSO) as core, as well as free haloperidol. Haloperidol-loaded lipid-core nanocapsules formulations were prepared, physicochemical characterized and administered (0.5 mg kg-1-ip) to rats for 28 days. Oral dyskinesia was evaluated acutely and subchronically and after that cell viability and free radical generation in cortex and substantia nigra. All formulations presented satisfactory physicochemical parameters. Acutely, all formulations were able to prevent oral dyskinesia development in comparison to free haloperidol, except haloperidol-loaded nanocapsules containing GSO, whose effect was only partial. After subchronic treatment, all haloperidol-loaded nanocapsules formulations prevented oral dyskinesia in relation to free drug. Also, haloperidol-loaded nanocapsules containing fish oil and GSO were more effective than caprylic/capric triglycerides nanocapsules and free haloperidol in cell viability preservation and control of free radical generation. Our findings showed that fish oil formulation may be considered as the best formulation of haloperidol-loaded lipid-core nanocapsules, being able to prevent motor side effects associated with chronic use of antipsychotic drugs, as haloperidol.

Paclitaxel and Erlotinib-co-loaded Solid Lipid Core Nanocapsules: Assessment of Physicochemical Characteristics and Cytotoxicity in Non-small Cell Lung Cancer.

PURPOSE: Lung cancer is the leading cause of cancer-related deaths. The aim of this study was to design solid lipid core nanocapsules (SLCN) comprising a solid lipid core and a PEGylated polymeric corona for paclitaxel (PTX) and erlotinib (ERL) co-delivery to non-small cell lung cancer (NSCLC), and evaluate their physicochemical characteristics and in vitro activity in NCI-H23 cells. METHODS: PTX/ERL-SLCN were prepared by nanoprecipitation and sonication and physicochemically characterized by dynamic light scattering, transmission electron microscopy, differential scanning calorimetry, X-ray diffraction, and Fourier-transform infrared spectroscopy. In vitro release profiles at pH 7.4 and pH 5.0 were studied and analyzed. In vitro cytotoxicity and cellular uptake and apoptosis assays were performed in NCI-H23 cells. RESULTS: PTX/ERL-SLCN exhibited appropriately-sized spherical particles with a high payload. Both PTX and ERL showed pH-dependent and sustained release in vitro profiles. PTX/ERL-SLCN demonstrated concentration- and time-dependent uptake by NCI-H23 cells and caused dose-dependent cytotoxicity in the cells, which was remarkably greater than that of not only the free individual drugs but also the free drug cocktail. Moreover, well-defined early and late apoptosis were observed with clearly visible signs of apoptotic nuclei. CONCLUSION: PTX/ERL-SLCN could be employed as an optimal approach for combination chemotherapy of NSCLC.

In vivo efficacy and evaluation of gel-cream containing dehydrated betamethasone dipropionate nanocapsules.

This study aimed to develop gel-creams from the lyophilised product of betamethasone dipropionate-loaded lipid-core nanocapsule suspensions and evaluated its efficacy in a model of contact dermatitis. The gel-creams were prepared and characterized followed by a study of in vitro drug penetration/permeation and its in vivo efficacy. The suspensions and lyophilised products showed nanometric size; the betamethasone content was 0.25 ± 0.01 mg/mL and the encapsulation efficiency was approximately 100%. The nanocapsules and redispersed powders presented control of the drug release. The gel-creams presented pH between 6.0-6.5 and exhibited non-Newtonian flow behavior, following the Herschel-Bulkley model. The skin penetration/permeation study indicated that betamethasone dipropionate can reach different skin layers. For in vivo efficacy, the contact dermatitis model was capable of causing tissue damage with changes in enzyme activities of the purinergic system in lymphocytes. The gel-creams showed the best dermatological and immunological efficacy and reduced oxidative damage in the evaluated tissues.

Redispersible spray-dried lipid-core nanocapsules intended for oral delivery: the influence of the particle number on redispersibility.

This study proposes a new approach to produce easily redispersible spray-dried lipid-core nanocapsules (LNC) intended for oral administration, evaluating the influence of the particle number density of the fed sample. The proposed approach to develop redispersible spray-dried LNC formulations intended for oral route is innovative, evidencing the needing of an optimization of the initial particle number density in the liquid suspension of nanocapsules. A mixture of maltodextrin and L-leucine (90:10 w/w) was used as drying adjuvant. Dynamic light scattering, turbidimetry, determination of surface area and pore size distribution, electron microscopy and confocal Raman microscopy (CRM) were used to characterize the proposed system and to better understand the differences in the redispersion behavior. An easily aqueous redispersion of the spray-dried powder composed of maltodextrin and L-leucine (90:10 w/w) was obtained, depending on the particle number density. Their surface area decreased in the presence of LNC. CRM enabled the visualization of the spatial distribution of the different compounds in the powders affording to better understand the influence of the particle number density of the fed sample on their redispersion behavior. This study shows the need for optimizing initial particle number density in the liquid formulation to develop redispersible spray-dried LNC powders.

Invasive characterization of atherosclerotic plaque in patients with peripheral arterial disease using near-infrared spectroscopy intravascular ultrasound.

OBJECTIVES: We describe the characteristics of atherosclerotic plaque in patients with peripheral arterial disease (PAD) using near-infrared spectroscopy-intravascular ultrasound (NIRS-IVUS) BACKGROUND: Imaging and autopsy studies have described atherosclerotic plaque in different vascular beds, including varying degrees of lipid, fibrosis, and calcification. Recently, NIRS has been validated as an accurate method for detecting lipid-core plaque (LCP) in the coronary circulation. Invasive evaluation of plaque composition using NIRS-IVUS has not been reported in different peripheral arterial circulations. METHODS: We performed invasive angiography and NIRS-IVUS in consecutive PAD patients prior to percutaneous revascularization. Imaging evaluation included parameters from angiography, IVUS, and NIRS. NIRS-IVUS findings were compared among different vascular beds with regard to the presence and extent of calcification and LCP. RESULTS: One hundred and forty-nine lesions in 126 PAD patients were enrolled, including the internal carotid (n = 10), subclavian/axillary (n = 9), renal (n = 14), iliac (n = 35), femoropopliteal (n = 69), and infrapopliteal (n = 12) arteries. Plaque morphology was calcified in 132 lesions (89%) and fibrous in 17 lesions (11%). Calcification varied from 100% of renal artery stenoses to 55% of subclavian/axillary artery stenoses. LCP was present in 48 lesions (32%) and prevalence varied from 60% in carotid artery stenoses to 0% in renal artery stenoses (P < 0.005). LCP was only observed in fibrocalcific plaque, and was longitudinally and circumferentially surrounded by a more extensive degree of calcium. CONCLUSIONS: NIRS-IVUS in stable PAD patients demonstrates a high frequency of calcific plaque and statistically significant differences in the frequency of LCP in different arterial beds. LCP, when present in the peripheral circulation, is always associated with calcified plaque. The strong co-localization of calcified plaque and LCP in severe PAD lesions may provide plaque-stabilizing effects; further studies are needed. © 2017 Wiley Periodicals, Inc.

Bromelain-Functionalized Multiple-Wall Lipid-Core Nanocapsules: Formulation, Chemical Structure and Antiproliferative Effect Against Human Breast Cancer Cells (MCF-7).

PURPOSE: This study was conducted a promising approach to surface functionalization developed for lipid-core nanocapsules and the merit to pursue new strategies to treat solid tumors. METHODS: Bromelain-functionalized multiple-wall lipid-core nanocapsules (Bro-MLNC-Zn) were produced by self-assembling following three steps of interfacial reactions. Physicochemical and structural characteristics, in vitro proteolytic activity (casein substrate) and antiproliferative activity (breast cancer cells, MCF-7) were determined. RESULTS: Bro-MLNC-Zn had z-average diameter of 135 nm and zeta potential of +23 mV. The complex is formed by a Zn-N chemical bond and a chelate with hydroxyl and carboxyl groups. Bromelain complexed at the nanocapsule surface maintained its proteolytic activity and showed anti-proliferative effect against human breast cancer cells (MCF-7) (72.6 ± 1.2% at 1.250 µg mL-1 and 65.5 ± 5.5% at 0.625 µg mL-1). Comparing Bro-MLNC-Zn and bromelain solution, the former needed a dose 160-folds lower than the latter for a similar effect. Tripan blue dye assay corroborated the results. CONCLUSIONS: The surface functionalization approach produced an innovative formulation having a much higher anti-proliferative effect than the bromelain solution, even though both in vitro proteolytic activity were similar, opening up a great opportunity for further studies in nanomedicine.

Bivalent mucosal peptide vaccines administered using the LCP carrier system stimulate protective immune responses against Streptococcus pyogenes infection.

Despite the broad knowledge about the pathogenicity of Streptococcus pyogenes there is still a controversy about the correlate of protection in GAS infections. We aimed in further improving the immune responses stimulated against GAS comparing different vaccine formulations including bis-(3',5')-cyclic dimeric adenosine monophosphate (c-di-AMP) and BPPCysMPEG, a derivative of the macrophage-activating lipopeptide (MALP-2), as adjuvants, respectively, to be administered with and without the universal T helper cell epitope P25 along with the optimized B cell epitope J14 of the M protein and B and T cell epitopes of SfbI. Lipopeptide based nano carrier systems (LCP) were used for efficient antigen delivery across the mucosal barrier. The stimulated immune responses were efficient in protecting mice against a respiratory challenge with a lethal dose of a heterologous S. pyogenes strain. Moreover, combination of the LCP based peptide vaccine with c-di-AMP allowed reduction of antigen dose at the same time maintaining vaccine efficacy.

The application of self-assembled nanostructures in peptide-based subunit vaccine development.

Peptide based-vaccines are becoming one of the most widely investigated prophylactic and therapeutic health care interventions against a variety of diseases, including cancer. However, the lack of a safe and highly efficient adjuvant (immune stimulant) is regarded as the biggest obstacle to vaccine development. The incorporation of a peptide antigen in a nanostructure-based delivery system was recently shown to overcome this obstacle. Nanostructures are often formed from antigens conjugated to molecules such as polymers, lipids, and peptide, with the help of self-assembly phenomenon. This review describes the application of self-assembly process for the production of peptide-based vaccine candidates and the ability of these nanostructures to stimulate humoral and cellular immune responses.