Resveratrol and Grape Extract-loaded Solid Lipid Nanoparticles for the Treatment of Alzheimer's Disease.

The aggregation of amyloid-ß peptide (Aß) has been linked to the formation of neuritic plaques, which are pathological hallmarks of Alzheimer's disease (AD). Various natural compounds have been suggested as therapeutics for AD. Among these compounds, resveratrol has aroused great interest due to its neuroprotective characteristics. Here, we provide evidence that grape skin and grape seed extracts increase the inhibition effect on Aß aggregation. However, after intravenous injection, resveratrol is rapidly metabolized into both glucuronic acid and sulfate conjugations of the phenolic groups in the liver and intestinal epithelial cells (within less than 2 h), which are then eliminated. In the present study, we show that solid lipid nanoparticles (SLNs) functionalized with an antibody, the anti-transferrin receptor monoclonal antibody (OX26 mAb), can work as a possible carrier to transport the extract to target the brain. Experiments on human brain-like endothelial cells show that the cellular uptake of the OX26 SLNs is substantially more efficient than that of normal SLNs and SLNs functionalized with an unspecific antibody. As a consequence, the transcytosis ability of these different SLNs is higher when functionalized with OX-26.

[The Health Care Revenue Cycle. Management in Brazil: Challenges that keep CEOs awaken].

Brazil's economic and political crisis had never been deeper, hardening the way companies deal on the market. Only those that are able to deal with tougher market conditions remain in the game, while facing increasingly difficult situations. A continuous rise in competition has shrunk prices and compressed margins, imposing necessary improvements to the way companies work in order to remain sustainable. The healthcare market is no exception, and if leaders identify improvement opportunities for the way their companies deal with Revenue Cycle Management, they will easily be one step ahead of competition.

Structural characterization of functionalized gold nanoparticles for drug delivery in cancer therapy: a NMR based approach.

In the present paper, we report results from a study of the structure and physicochemical properties of gold nanoparticles modified with poly(ethylene glycol) (PEG) designed for the drug delivery of the proteasome inhibitor Bortezomib (BTZ) in cancer therapy. A number of advanced analytical techniques were used to define important physicochemical characteristics such as composition, structure, surface properties, particle size and morphology. A new approach based on detailed NMR studies was employed to define specific intermolecular interactions and mechanisms of drug immobilization and location into surface modified gold nanoparticles (AuNPs). Particularly important information was gained from analysis of NMR spectroscopic parameters such as the spectral line shape, translation diffusion, the nuclear Overhauser effect (NOE) and spin-lattice relaxation (T1). The results confirmed the coexistence of two different types of BTZ inclusion into polyethylene glycol coated gold nanoparticles: (i) association with the polymer chains by weak H-bonds and/or dipole-charge interactions and (ii) adsorption on the surface of the gold nanoparticles. The results allowed for determination of the overall structure of Bortezomib loaded PEG coated AuNPs, which is related to the therapeutic drug efficacy and activity in the treatment of cancer.

Transferrin Receptor-Targeted Nanocarriers: Overcoming Barriers to Treat Glioblastoma.

Glioblastoma multiforme (GBM) is the most common and lethal type of brain tumor, and the clinically available approaches for its treatment are not curative. Despite the intensive research, biological barriers such as the blood-brain barrier (BBB) and tumor cell membranes are major obstacles to developing novel effective therapies. Nanoparticles (NPs) have been explored as drug delivery systems (DDS) to improve GBM therapeutic strategies. NPs can circumvent many of the biological barriers posed by this devastating disease, enhancing drug accumulation in the target site. This can be achieved by employing strategies to target the transferrin receptor (TfR), which is heavily distributed in BBB and GBM cells. These targeting strategies comprise the modification of NPs' surface with various molecules, such as transferrin (Tf), antibodies, and targeting peptides. This review provides an overview and discussion on the recent advances concerning the strategies to target the TfR in the treatment of GBM, as their benefits and limitations.

Nanocarriers Based on Gold Nanoparticles for Epigallocatechin Gallate Delivery in Cancer Cells.

Gold nanoparticles (AuNPs) are inorganic and biocompatible nanovehicles capable of conjugating biomolecules to enhance their efficacy in cancer treatment. The high and reactive surface area provides good advantages for conjugating active compounds. Two approaches were developed in this work to improve the Epigallocatechin-3-gallate (EGCG) antioxidant efficacy. AuNPs were synthesized by reducing gold salt with chitosan. One other nanosystem was developed by functionalizing AuNPs with cysteamine using the Turkevitch method. The physico-chemical characterization of EGCG conjugated in the two nanosystems-based gold nanoparticles was achieved. The in vitro toxic effect induced by the nanoconjugates was evaluated in pancreatic cancer cells, showing that encapsulated EGCG keeps its antioxidant activity and decreasing the BxPC3 cell growth. A significant cell growth inhibition was observed in 50% with EGCG concentrations in the range of 2.2 and 3.7 µM in EGCG-ChAuNPs and EGCG-Cyst-AuNPs nanoconjugates, respectively. The EGCG alone had to be present at 23 µM to induce the same cytotoxicity response. Caspase-3 activity assay demonstrated that the conjugation of EGCG induces an enhancement of BxPC3 apoptosis compared with EGCG alone. In conclusion, AuNPs complexes can be used as delivery carriers to increase EGCG antioxidant activity in cancer tissues.

Drug delivery in glioblastoma therapy: a review on nanoparticles targeting MGMT-mediated resistance.

INTRODUCTION: Glioblastoma multiforme (GBM) is the deadliest type of brain cancer with poor response to the available therapies, mainly due to intrinsic resistance mechanisms. Chemotherapy is based on alkylating agents, but DNA-repair mechanisms can revert this cytotoxic effect. O6-methylguanine-DNA methyltransferase (MGMT) protein is the primary mechanism for GBM resistance. Therefore, different strategies to suppress its activity have been explored. However, their clinical use has been hindered due to the high toxicity of MGMT inhibitors verified in clinical trials. AREAS COVERED: This review article aims to provide the current progress in the development of novel drug delivery systems (DDS) to overcome this resistance. Here, we also review the current knowledge on MGMT-mediated resistance and the clinical outcomes and potential risks of using MGMT inhibitors. EXPERT OPINION: To overcome therapeutic limitations, nano-based approaches have been proposed as a suitable solution to improve drug accumulation in the brain tumor tissue and decrease systemic toxicity. DDS to overcome MGMT-mediated resistance in GBM have been mostly developed to deliver MGMT inhibitors and for gene therapy to modulate MGMT gene expression.

Controlling amyloid-beta peptide(1-42) oligomerization and toxicity by fluorinated nanoparticles.

The amyloid-beta peptide (Abeta) is a major fibrillar component of neuritic plaques in Alzheimer's disease brains and is related to the pathogenesis of the disease. Soluble oligomers that precede fibril formation have been proposed as the main neurotoxic species that contributes to neurodegeneration and dementia. We hypothesize that oligomerization and cytotoxicity can be repressed by nanoparticles (NPs) that induce conformational changes in Abeta42. We show here that fluorinated and hydrogenated NPs with different abilities to change Abeta42 conformation influence oligomerization as assessed by atomic force microscopy, immunoblot and SDS-PAGE. Fluorinated NPs, which promote an increase in alpha-helical content, exert an antioligomeric effect, whereas hydrogenated analogues do not and lead to aggregation. Cytotoxicity assays confirmed our hypothesis by indicating that the conformational conversion of Abeta42 into an alpha-helical-enriched secondary structure also has antiapoptotic activity, thereby increasing the viability of cells treated with oligomeric species.

Color Doppler ultrasonographic scanning in acute bacterial prostatitis.

OBJECTIVES: The purpose of this study was to reveal parenchymal and vascular changes in acute prostatitis and to determine the role of color Doppler sonography in monitoring patients with this pathology. MATERIAL AND METHODS: Twenty five patients with a clinical diagnosis of acute bacterial prostatitis (NIH 1) admitted to our institution were studied prospectively. Clinical, analytical and microbiological data were recorded. Color Doppler and transrectal ultrasonography (TRUS) were performed 1 week after antibiotic therapy and afterwards at 6 weeks, 3 and 6 month visits. The findings were recorded and scored using standardized criteria to characterize the degree and distribution of prostatic vascularity. RESULTS: Blood flow was observed to the entire prostate capsule (grade 2) in 23 (92%) patients at first visit (1 week) and were present in 11 (44%), 6 (24%) and 2 (8%) at 6 weeks, 3 and 6 month visits respectively. The amount and distribution of blood flow within the prostatic parenchyma were evaluated using several criteria. Using the 2-point scale flow were classified as grade 2 22 (88%), 18 (72%), 12 (48%) and 3 (12%) patients at first, second, third and fourth visit respectively. Similar findings were noted using the Doppler spot scale which revealed that flow was grade 2 (15 spots or more) in 23 (92%), 19 (76%), 11 (44%) and 3 (12%) patients respectively. Mean number of Doppler spots in the prostate parenchyma was 23.1 +/- 11.1 at first visit, 10.3 +/- 9.5 after the end of therapy and 8.3 +/- 5.4 and 7.9 +/- 5.1 at 3 and 6 monthly respectively. CONCLUSIONS: Patients with acute prostatitis require prolonged treatment and subsequent follow up for at least 6 months. Color Doppler sonography is a useful tool in monitoring response to treatment and in predicting clinical outcome.

Molecular interactions between Vitamin B12 and membrane models: A biophysical study for new insights into the bioavailability of Vitamin.

Vitamin B12 (VB12) deficiency is one of the most common malnutrition problems worldwide and is related to its poor bioavailability. The lipid composition of cell membranes and molecule-cell membrane lipid interactions are major factors affecting the bioavailability of nutrients. So, the study of these interactions may allow predicting the behavior of VB12 at cellular membranes and the effects on its activity. Thus, lipid vesicles with lipid composition similar to the majority of eukaryotic cell membranes were used as biomembrane models, and their interactions with VB12 molecules were evaluated. For that, different parameters were assessed such as the lipophilicity of VB12, its preferential location in the membrane and its effect on the physical properties of the bilayer. VB12 showed high affinity for the biological membranes, not inducing any biophysical changes in their properties. The interactions of VB12 with the membrane was affected by the complexity of the bilayer, since its increase in order and rigidity hinders the diffusion of molecules. Thus, the low bioavailability of VB12 is not related with its interactions with the biological membranes.

Design and biological activity of beta-sheet breaker peptide conjugates.

The sequence LPFFD (iAbeta(5)) prevents amyloid-beta peptide (Abeta) fibrillogenesis and neurotoxicity, hallmarks of Alzheimer's disease (AD), as previously demonstrated. In this study iAbeta(5) was covalently linked to poly(ethylene glycol) (PEG) and the activity of conjugates was assessed and compared to the activity of the peptide alone by in vitro studies. The conjugates were characterized by MALDI-TOF. Competition binding assays established that conjugates retained the ability to bind Abeta with similar strength as iAbeta(5). Transmission electron microscopy analysis showed that iAbeta(5) conjugates inhibited amyloid fibril formation, which is in agreement with binding properties observed for the conjugates towards Abeta. The conjugates were also able to prevent amyloid-induced cell death, as evaluated by activation of caspase 3. These results demonstrated that the biological activity of iAbeta(5) is not affected by the pegylation process.

Doxorubicin and Varlitinib Delivery by Functionalized Gold Nanoparticles Against Human Pancreatic Adenocarcinoma.

The aim of this study was to develop drug delivery nanosystems based on pegylated gold nanoparticles (PEGAuNPs) for a combination against pancreatic cancer cells. Doxorubicin and varlitinib, an anthracycline and a tyrosine kinase inhibitor respectively, were conjugated with gold nanoparticles. The systems were characterized, after synthesis, regarding their size, stability and morphology. An efficient conjugation of doxorubicin and varlitinib with PEGAuNPs was revealed. The cytotoxicity effect induced by the combination of the nanoconjugates was investigated in pancreatic cancer cell lines. Doxorubicin and varlitinib conjugated with PEGAuNPs revealed a combined effect to decrease the cell survival of the cancer line S2-013s, while reducing the drugs' toxicity for the healthy pancreatic cells hTERT-HPNE. This study highlights the promising potential of PEGAuNPs for targeted delivery of therapeutic drugs into human cells, enhancing the antitumor growth-inhibition effect on cancer cells, and decreasing the toxicity against normal cells. In cancer therapy, the present approach based on PEGAuNP functionalization can be further explored to increase drug targeting efficiency and to reduce side effects.

Factorial Design as a Tool for the Optimization of PLGA Nanoparticles for the Co-Delivery of Temozolomide and O6-Benzylguanine.

Poly(d,l-lactic-co-glycolic) (PLGA) nanoparticles (NPs) have been widely studied for several applications due to their advantageous properties, such as biocompatibility and biodegradability. Therefore, these nanocarriers could be a suitable approach for glioblastoma multiforme (GBM) therapy. The treatment of this type of tumours remains a challenge due to intrinsic resistance mechanisms. Thus, new approaches must be envisaged to target GBM tumour cells potentially providing an efficient treatment. Co-delivery of temozolomide (TMZ) and O6-benzylguanine (O6BG), an inhibitor of DNA repair, could provide good therapeutic outcomes. In this work, a fractional factorial design (FFD) was employed to produce an optimal PLGA-based nanoformulation for the co-loading of both molecules, using a reduced number of observations. The developed NPs exhibited optimal physicochemical properties for brain delivery (dimensions below 200 nm and negative zeta potential), high encapsulation efficiencies (EE) for both drugs, and showed a sustained drug release for several days. Therefore, the use of an FFD allowed for the development of a nanoformulation with optimal properties for the co-delivery of TMZ and O6BG to the brain.

Biophysical interaction of temozolomide and its active metabolite with biomembrane models: The relevance of drug-membrane interaction for Glioblastoma Multiforme therapy.

Temozolomide (TMZ) is the first-line treatment for Glioblastoma Multiforme (GBM). After administration, TMZ is rapidly converted into its active metabolite (MTIC). However, its pharmacological activity is reduced due MTIC low bioavailability in the brain. Since drugs' permeability through biological barriers and tumor cell membranes affects its bioavailability, the ability of MTIC to interact with the biological membranes presents a major contribution on its pharmacological properties and activity. Biomembrane models mimic the physiological conditions, allowing to predict the drug's behavior at biological membranes and its effects on drug biodistribution profiles. In this work, lipid bilayer models using liposomes were applied for the drug-membrane interaction studies. The zwitterionic phospholipid, 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), and cholesterol were chosen for the composition of the model, since they represent the major components of the membranes of GBM cells and brain capillary endothelial cell. Thus, the molecular interactions between MTIC and these models were studied by the evaluation of the partition of the drug into the phospholipid's membrane, its location within the bilayer and its effect on the fluidity of the membrane. The attained results suggest that the composition of membranes affects drugs partition, showing that drug biodistribution depends not only on its physicochemical features, but also depends on the characteristics of the membrane such as the packing of the lipid molecules. Also, MTIC exhibited low affinity to biological membranes, explaining its low bioavailability on the target cells.

Influence of fluorinated and hydrogenated nanoparticles on the structure and fibrillogenesis of amyloid beta-peptide.

Peptide aggregation in amyloid fibrils is implicated in the pathogenesis of several diseases such as Alzheimer's disease. There is a strong correlation between amyloid fibril formation and a decrease in conformational stability of the native state. Amyloid-beta peptide (Abeta), the aggregating peptide in Alzheimer's disease, is natively unfolded. The deposits found in Alzheimer's disease are composed of Abeta fibrillar aggregates rich in beta-sheet structure. The influence of fluorinated complexes on the secondary structure and fibrillogenesis of Abeta peptide was studied by circular dichroism (CD) spectroscopy and transmission electron microscopy (TEM). CD spectra show that complexes of polyampholyte and fluorinated dodecanoic acid induce alpha-helix structure in Abeta, but their hydrogenated analogous lead to beta-sheet formation and aggregation. The fluorinated nanoparticles with highly negative zeta potential and hydrophobic fluorinated core have the fundamental characteristics to prevent Abeta fibrillogenesis.

Gold Nanoparticles for Targeting Varlitinib to Human Pancreatic Cancer Cells.

Colloidal gold nanoparticles are targeting probes to improve varlitinib delivery into cancer cells. The nanoconjugates were designed by the bioconjugation of pegylated gold nanoparticles with varlitinib via carbodiimide-mediated cross-linking and characterized by infrared and X-ray photoelectron spectroscopy. The drug release response shows an initial delay and a complete drug release after 72 h is detected. In vitro experiments with MIA PaCa-2 cells corroborate that PEGAuNPsVarl conjugates increase the varlitinib toxic effect at very low concentrations (IC50 = 80 nM) if compared with varlitinib alone (IC50 = 259 nM). Our results acknowledge a decrease of drug side effects in normal cells and an enhancement of drug efficacy against to the pancreatic cancer cells reported.

Development of Parvifloron D-loaded Smart Nanoparticles to Target Pancreatic Cancer.

Pancreatic cancer is the eighth leading cause of cancer death worldwide. For this reason, the development of more effective therapies is a major concern for the scientific community. Accordingly, plants belonging to Plectranthus genus and their isolated compounds, such as Parvifloron D, were found to have cytotoxic and antiproliferative activities. However, Parvifloron D is a very low water-soluble compound. Thus, nanotechnology can be a promising delivery system to enhance drug solubility and targeted delivery. The extraction of Parvifloron D from P. ecklonii was optimized through an acetone ultrasound-assisted method and isolated by Flash-Dry Column Chromatography. Then, its antiproliferative effect was selectivity evaluated against different tumor cell lines (IC50 of 0.15 ± 0.05 µM, 11.9 ± 0.7 µM, 21.6 ± 0.5, 34.3 ± 4.1 µM, 35.1 ± 2.2 µM and 32.1 ± 4.3 µM for BxPC3, PANC-1, Ins1-E, MCF-7, HaCat and Caco-2, respectively). To obtain an optimized stable Parvifloron D pharmaceutical dosage form, albumin nanoparticles were produced through a desolvation method (yield of encapsulation of 91.2%) and characterized in terms of size (165 nm; PI 0.11), zeta potential (-7.88 mV) and morphology. In conclusion, Parvifloron D can be efficiently obtained from P. ecklonii and it has shown selective cytotoxicity to pancreatic cell lines. Parvifloron D nanoencapsulation can be considered as a possible efficient alternative approach in the treatment of pancreatic cancer.

Functionalized gold nanoparticles improve afatinib delivery into cancer cells.

OBJECTIVES: A drug delivery system based on colloidal pegylated gold nanoparticles (PEGAuNPs) conjugated with the tyrosine kinase inhibitor afatinib was designed and tested for enhancing the drug activity against pancreatic and NSCLC cells. METHODS: PEGAuNPs were synthesized and characterized physicochemically. Confocal imaging was performed to evaluate the nanoparticle (NP) internalization in cancer cells. For cell-cycle distribution analysis, conjugated NPs and afatinib alone were incubated with cells and alterations on the cell-cycle profile subsequently analyzed by total DNA staining. Cancer cell survival and growth inhibition following incubation with afatinib and PEGAuNPs-afatinib (concentrations between 0.007 and 0.500 µM afatinib) were evaluated. RESULTS: A higher cellular uptake of PEGAuNPs was observed by cancer cells. Our data suggest an efficient conjugation of PEGAuNPs with the drug, enhancing the afatinib activity in comparison with afatinib alone. In fact, IC50 and GI50 results obtained show that the PEGAuNPs-afatinib conjugate is ca. 5 and 20 times more potent than afatinib alone in S2-013 and A549 cell lines, respectively. CONCLUSIONS: Conjugating PEGAuNPs with afatinib is a promising antitumor delivery system for cancer therapy as it improves drug efficacy, allowing a reduction in drug dose used and minimizing possible toxicity-related side effects.

Cellular uptake of PLGA nanoparticles targeted with anti-amyloid and anti-transferrin receptor antibodies for Alzheimer's disease treatment.

During the last few decades, relevant efforts have been reported to design nanocarriers for drug transport through the blood brain barrier (BBB). New drugs, such as peptide iAß5, capable to inhibit the aggregates associated with Alzheimers disease (AD) are being tested but the most frequent drawback is to reach the brain in the desired concentrations due to the low BBB permeability-surface area. Our approach, as a proof of concept to improve drug transport through the BBB, is based on poly(lactic-co-glycolic acid) (PLGA) nanoparticles with surface functionalized with anti-transferrin receptor monoclonal antibody (OX26) and anti-Aß (DE2B4) to deliver encapsulated iAß5 into the brain. Porcine brain capillary endothelial cells (PBCECs) were used as a BBB model to evaluate the system efficacy and toxicity. The uptake of immune nanoparticles with a controlled delivery of the peptide iAß5 was substantially increased compared to the nanoparticles (NPs) without monoclonal antibody functionalization.

Enhancing the efficiency of bortezomib conjugated to pegylated gold nanoparticles: an in vitro study on human pancreatic cancer cells and adenocarcinoma human lung alveolar basal epithelial cells.

OBJECTIVES: Gold nanoparticles have become promising vectors for cancer diagnosis and treatment. The present study investigates the effect of bortezomib (BTZ), a proteasome inhibitor, conjugated with pegylated gold nanoparticles (PEGAuNPs) in pancreatic and lung cancer cells. METHODS: Synthesized gold nanoparticles (PEGAuNPs) were conjugated with bortezomib antitumor drug. We investigated the cytotoxicity induced by BTZ conjugated with functionalized gold nanoparticles in vitro, in the human pancreatic (S2-013) and lung (A549) cancer cell lines. RESULTS: We found an efficient of conjugation of BTZ with PEGAuNPs. In vitro assays showed that after 72 h' incubation with PEGAuNPs-BTZ cancer cells revealed alterations in morphology; also for S2-013 and A549 cancer cells, the IC50 value of free BTZ is respectively 1.5 and 4.3 times higher than the IC50 value of PEGAuNPs-BTZ. Furthermore, for TERT-HPNE, the IC50 value is around 63 times lower for free BTZ than the conjugated nanovehicle. Cell growth inhibition results showed a remarkable enhancement in the effect of BTZ when conjugated with AuNPs. CONCLUSIONS: Our findings showed that conjugation with PEGAuNPs enhance the BTZ growth-inhibition effect on human cancer cells (S2-013 and A549) and decreases its toxicity against normal cells (TERT-HPNE).

Inflammatory Myofibroblastic Tumor of the Bladder: 2 Rare Cases Managed with Laparoscopic Partial Cystectomy.

Two cases of inflammatory myofibroblastic tumor (IMT) of the bladder are reported here. Both patients were male and presented with macroscopic hematuria; in the first case terminal hematuria was associated with irritative voiding symptoms. The second case was a smoker with hematuria unresponsive to medical treatment and anemia. Clinical presentation, pathological features, treatment, and prognosis are discussed. Due to rarity of this pathological condition, there are no guidelines concerning treatment and follow-up. We present our follow-up scheme and highlight the use of laparoscopic partial cystectomy as a successful treatment approach.