Criticality of Surface Characteristics of Intravenous Iron-Carbohydrate Nanoparticle Complexes: Implications for Pharmacokinetics and Pharmacodynamics.

Un-complexed polynuclear ferric oxyhydroxide cannot be administered safely or effectively to patients. When polynuclear iron cores are formed with carbohydrates of various structures, stable complexes with surface carbohydrates driven by multiple interacting sites and forces are formed. These complexes deliver iron in a usable form to the body while avoiding the serious adverse effects of un-complexed forms of iron, such as polynuclear ferric oxyhydroxide. The rate and extent of plasma clearance and tissue biodistribution is variable among the commercially available iron-carbohydrate complexes and is driven principally by the surface characteristics of the complexes which dictate macrophage opsonization. The surface chemistry differences between the iron-carbohydrate complexes results in significant differences in in vivo pharmacokinetic and pharmacodynamic profiles as well as adverse event profiles, demonstrating that the entire iron-carbohydrate complex furnishes the pharmacologic action for these complex products. Currently available physicochemical characterization methods have limitations in biorelevant matrices resulting in challenges in defining critical quality attributes for surface characteristics for this class of complex nanomedicines.

Carbohydrate based biomarkers enable hybrid near infrared fluorescence and 64Cu based radio-guidance for improved surgical precision.

Increasing numbers of lung tumors are identified at early disease stages by diagnostic imaging in screening programs, but difficulties in locating these during surgical intervention has prevented an improved treatment outcome. Surgical biomarkers that are visible on diagnostic images, and that provide the surgeon with real-time image guidance during the intervention are thus highly warranted to bridge diagnostic precision into enhanced therapeutic outcome. In this paper, a liquid soft tissue marker for near infrared fluorescence and radio-guidance is presented. The biocompatible marker is based on the carbohydrate ester, sucrose acetate isobutyrate, ethanol, and a multifunctional naphthalocyanine dye, which enable near infrared fluorescence image-guided resection at short, medium and long tissue depths. Naphthalocyanine dyes have high quantum yields and may further act as chelators of radionuclides. Upon injection of the liquid marker, a gel-like depot is formed in situ at the site of injection, wherein the fluorescent dye and radionuclide is retained. The radiolabeled markers were optimized for minimal fluorescence quenching and high retention of the positron emission tomography radionuclide 64Cu. The performance of the radiolabeled marker was tested in vivo in mice, where it displayed high photostability over a period of 4 weeks, and high retention of 64Cu for 48 hours. The retention and biodistribution of 64Cu was quantified via PET/CT, and the fluorescence emission by an in vivo imaging system. The presented data demonstrate proof-of-concept for naphthalocyanine markers as multimodal imaging agents that can bridge the precision of diagnostic imaging into surgical interventions.

Processing of four different cooking methods of Oudemansiella radicata: Effects on in vitro bioaccessibility of nutrients and antioxidant activity.

The purpose of this study is to evaluate the bioaccessibility of nutrients and antioxidant activity of O. radicata after subjecting to four types of domestic cooking and followed by in vitro digestion. The result demonstrated that the group with the lowest amino acid release and the degree of protein hydrolysis (5.6%) was frying, but both reducing sugar content and antioxidant activity were the highest. The composition of fatty acids was different than undigested samples, especially the relative content of linolenic acid was significantly decreased (e.g., 34.49 to 8.23%, boiled). The difference of the minerals bioaccessibility was slightly affected by the cooking method, but mainly related to their natural properties, such as the highest phosphorus (62.73%) and the lowest iron (21.53%) in the steaming. The above data provides a starting point for the design of processes at an industrial and gastronomic level.

Current strategies in extending half-lives of therapeutic proteins.

Macromolecular protein and peptide therapeutics have been proven to be effective in treating critical human diseases precisely. Thanks to biotechnological advancement, a huge number of proteins and peptide therapeutics were made their way to pharmaceutical market in past few decades. However, one of the biggest challenges to be addressed for protein therapeutics during clinical application is their fast degradation in serum and quick elimination owing to enzymatic degradation, renal clearance, liver metabolism and immunogenicity, attributing to the short half-lives. Size and hydrophobicity of protein molecules make them prone to kidney filtration and liver metabolism. On the other hand, proteasomes responsible for protein destruction possess the capability of specifically recognizing almost all kinds of foreign proteins while avoiding any unwanted destruction of cellular components. At present almost all protein-based drug formulations available in market are administered intravenously (IV) or subcutaneously (SC) with high dosing at frequent interval, eventually creating dose-fluctuation-related complications and reducing patient compliance vastly. Therefore, artificially increasing the therapeutic half-life of a protein by attaching to it a molecule that increases the overall size (eg, PEG) or helps with receptor mediated recycling (eg, albumin), or manipulating amino acid chain in a way that makes it more prone towards aggregate formation, are some of the revolutionary approaches to avoid the fast degradation in vivo. Half-life extension technologies that are capable of dramatically enhancing half-lives of proteins in circulation (2-100 folds) and thus improving their overall pharmacokinetic (PK) parameters have been successfully applied on a wide range of protein therapeutics from hormones and enzymes, growth factor, clotting factor to interferon. The focus of the review is to assess the technological advancements made so far in enhancing circulatory half-lives and improving therapeutic potency of proteins.

Feeding a slowly digestible carbohydrate diet during pregnancy of insulin-resistant rats prevents the excess of adipogenesis in their offspring.

An obesogenic environment during pregnancy has been shown to increase the risk of dysregulation on adipogenesis and insulin resistance in the offspring. Being essential for the growing fetus, glucose supply is guaranteed by a number of modifications in the mother's metabolism, and thus, glucose control during pregnancy especially among obese or diabetic women is paramount to prevent adverse consequences in their children. Besides the election of low-glycemic-index carbohydrates, the rate of carbohydrate digestion could be relevant to keep a good glucose control. In the present study, we compared the effects of two high-fat diets with similar glycemic load but different rates of carbohydrate digestion given to pregnant insulin-resistant rats. After birth, all animals were fed a standard diet until age 14 weeks. We analyzed offspring body composition, plasma and adipocyte lipidomics, lipid metabolism in adipose tissue and insulin sensitivity. Those animals whose mothers were fed the rapid-digesting carbohydrate diet exhibited an excessive adipogenesis. Thus, these animals showed a marked lipidemia, increased lipid synthesis in the adipose tissue and reduced glucose transporter amount in the adipose. On the contrary, those animals whose mothers were fed the slow-digesting carbohydrate diet showed a profile in the measured parameters closer to that of the offspring of healthy mothers. These results support the hypothesis that not only glycemic index but the rate of carbohydrate digestion during gestation may be critical to regulate the programming of adipogenesis in the offspring.

Polyphenols and Their Interactions With Other Dietary Compounds: Implications for Human Health.

Regular and optimal intake of polyphenols associates with numerous health-promoting effects. Bioavailability and activity of polyphenols depend on foods' structure and interactions with other food constituents, especially proteins, lipids, and carbohydrates. Polyphenols-proteins interactions can result in various biological effects, such as sense of astringency. So far, polyphenols interactions with food lipids have not been of special importance, except in case of plant oils. Polyphenols-carbohydrates interactions can influence the organoleptic properties, while interactions with dietary fibers are particularly significant. Polyphenols can decrease the synthesis of fats and fatty acids in the liver, or delay their absorption in intestines. Also, polyphenols can slow down digestion of carbohydrates, through the inhibition of digestive enzymes or modulation of glucose uptake. Both animal and plant proteins have low impact on the bioavailability of polyphenols, but some in vitro studies reported that milk proteins could enhance intestinal absorption of polyphenols from tea. Dietary fats may alter the passage of polyphenols through gastrointestinal tract and impact absorption of more hydrophobic polyphenols in particular. While some studies reported that associations with carbohydrates could decrease bioavailability of polyphenols, the others showed the opposite effects. Macronutrients can be used for encapsulation of polyphenols, which can increase their bioavailability and ensure controlled and targeted release. Polyphenols' interactions in the body include their incorporation in cell membranes which causes changes in fatty acid profile and impacts membrane-bound transporters and enzymes. Finally, gut microbiota plays essential role in metabolism of both polyphenols and macronutrients and thus can have great impact on their interactions.

Normal gastric emptying time of a carbohydrate-rich drink in elderly patients with acute hip fracture: a pilot study.

BACKGROUND: Guidelines for fasting in elderly patients with acute hip fracture are the same as for other trauma patients, and longer than for elective patients. The reason is assumed stress-induced delayed gastric emptying with possible risk of pulmonary aspiration. Prolonged fasting in elderly patients may have serious negative metabolic consequences. The aim of our study was to investigate whether the preoperative gastric emptying was delayed in elderly women scheduled for surgery due to acute hip fracture. METHODS: In a prospective study gastric emptying of 400 ml 12.6% carbohydrate rich drink was investigated in nine elderly women, age 77-97, with acute hip fracture. The emptying time was assessed by the paracetamol absorption technique, and lag phase and gastric half-emptying time was compared with two gender-matched reference groups: ten elective hip replacement patients, age 45-71 and ten healthy volunteers, age 28-55. RESULTS: The mean gastric half-emptying time in the elderly study group was 53 ± 5 (39-82) minutes with an expected gastric emptying profile. The reference groups had a mean half-emptying time of 58 ± 4 (41-106) and 59 ± 5 (33-72) minutes, indicating normal gastric emptying time in elderly with hip fracture. CONCLUSION: This pilot study in women with an acute hip fracture shows no evidence of delayed gastric emptying after an orally taken carbohydrate-rich beverage during the pre-operative fasting period. This implies no increased risk of pulmonary aspiration in these patients. Therefore, we advocate oral pre-operative management with carbohydrate-rich beverage in order to mitigate fasting-induced additive stress in the elderly with hip fracture. TRIAL REGISTRATION: ClinicalTrials.gov NCT02753010 . Registered 17 April 2016, retrospectively.

Lucerastat, an iminosugar with potential as substrate reduction therapy for glycolipid storage disorders: safety, tolerability, and pharmacokinetics in healthy subjects.

BACKGROUND: Lucerastat, an inhibitor of glucosylceramide synthase, has the potential to restore the balance between synthesis and degradation of glycosphingolipids in glycolipid storage disorders such as Gaucher disease and Fabry disease. The safety, tolerability, and pharmacokinetics of oral lucerastat were evaluated in two separate randomized, double-blind, placebo-controlled, single- and multiple-ascending dose studies (SAD and MAD, respectively) in healthy male subjects. METHODS: In the SAD study, 31 subjects received placebo or a single oral dose of 100, 300, 500, or 1000 mg lucerastat. Eight additional subjects received two doses of 1000 mg lucerastat or placebo separated by 12 h. In the MAD study, 37 subjects received placebo or 200, 500, or 1000 mg b.i.d. lucerastat for 7 consecutive days. Six subjects in the 500 mg cohort received lucerastat in both absence and presence of food. RESULTS: In the SAD study, 15 adverse events (AEs) were reported in ten subjects. Eighteen AEs were reported in 15 subjects in the MAD study, in which the 500 mg dose cohort was repeated because of elevated alanine aminotransferase (ALT) values in 4 subjects, not observed in other dose cohorts. No severe or serious AE was observed. No clinically relevant abnormalities regarding vital signs and 12-lead electrocardiograms were observed. Lucerastat Cmax values were comparable between studies, with geometric mean Cmax 10.5 (95% CI: 7.5, 14.7) and 11.1 (95% CI: 8.7, 14.2) µg/mL in the SAD and MAD study, respectively, after 1000 mg lucerastat b.i.d. tmax (0.5 - 4 h) and t1/2 (3.6 - 8.1 h) were also within the same range across dose groups in both studies. Using the Gough power model, dose proportionality was confirmed in the SAD study for Cmax and AUC0-∞, and for AUC0-12 in the MAD study. Fed-to-fasted geometric mean ratio for AUC0-12 was 0.93 (90% CI: 0.80, 1.07) and tmax was the same with or without food, indicating no food effect. CONCLUSIONS: Incidence of drug-related AEs did not increase with dose. No serious AEs were reported for any subject. Overall, lucerastat was well tolerated. These results warrant further investigation of substrate reduction therapy with lucerastat in patients with glycolipid storage disorders. SAD study was registered on clinicaltrials.gov under the identifier NCT02944487 on the 24th of October 2016 (retrospectively registered). MAD study was registered on clinicaltrials.gov under the identifier NCT02944474 on the 25th of October 2016 (retrospectively registered). TRIAL REGISTRATION: A Study to Assess the Safety and Tolerability of Lucerastat in Subjects With Fabry Disease. Clinicaltrials.gov: NCT02930655 .

Glycosylation and Activities of Natural Products.

Natural products are widely found in nature, their number and variety are numerous, the structures are complex and diverse. These natural products have many physiological and pharmacological activities. Glycosylation can increase the diversity of structure and function of natural product, it has become the focus of drug research and development. The impacts of glycosylation of natural products to water solubility, pharmacological activities, bioavailability, or others were described in this review, which provides a reference for the development and application of glycosylated natural products.

Differential trafficking of saccharidic probes following aspirin in clinical tests of intestinal permeability in young healthy women.

The effects of inflammatory changes on the absorption of different-sized probes and their permeability ratios are poorly understood. The aim of the present study was to determine the effects of a pharmacological agent on the permeability of the gut mucosa to saccharidic probes of larger and smaller molecular weight. Permeability was assessed by half-hourly urinary excretion of a combined dose of d-mannitol, l-rhamnose and lactulose following consumption of a single 600 mg dose of aspirin and compared with a placebo in a cross-over study in 20 healthy female volunteers. The temporal patterns of excretion of all probes were bimodal, being best fitted by polynomial functions. The relatively small early peak was evident for at least 4 h for smaller sugars, but was less evident with lactulose, being overshadowed by a larger second peak. These conclusions were further supported by separate analyses of the segments of the temporal plots between 2.5 and 4 h and between 4.5 and 6 h. The forms of these curves did not change significantly following dosing with aspirin. A greater proportion of the total dose of mannitol than rhamnose was excreted over the collection period. Following the consumption of aspirin, the cumulative rate of excretion of the smaller sugars (i.e. mannitol and rhamnose) was significantly reduced whereas that of lactulose was increased over the 6 h collection period. Aspirin has opposite effects on the absorption of larger and smaller probes, influencing the outcome of the test. These results have important consequences for the design and comparison of clinical tests of permeability.

α-Amylase inhibitory activity from nut seed skin polyphenols. 1. Purification and characterization of almond seed skin polyphenols.

Using α-amylase inhibition as a separation guide, polyphenolic compounds from almond ( Prunus dulcis ) seed skin were purified using ultrafiltration and Sephadex LH-20 and ODS columns. The purified fraction specifically and strongly inhibited α-amylase; the IC50 value was 2.2 µg/mL for pig pancreatic α-amylase. The fraction contained about 62% of the total polyphenols, 33.8% flavanol-type tannins and 30% procyanidins. Oral administration of the polyphenol fraction to rats fed corn starch significantly suppressed an increase in blood glucose levels and area under the curve (AUC), in a dose-dependent manner. High-resolution MALDI-TOF mass spectra showed that the structure of this sample is a series of polyflavan-3-ol polymers composed of catechin/epicatechin units and gallocatechin/epigallocatechin units up to 11-mer with several interflavanoid ether linkages. The results suggest almond seed skin contains highly polymerized polyphenols with strong α-amylase inhibitory activity, which retard absorption of carbohydrate.

Targeted nanoparticles with novel non-peptidic ligands for oral delivery.

Orally administered targeted nanoparticles have a large number of potential biomedical applications and display several putative advantages for oral drug delivery, such as the protection of fragile drugs or modification of drug pharmacokinetics. These advantages notwithstanding, oral drug delivery by nanoparticles remains challenging. The optimization of particle size and surface properties and targeting by ligand grafting have been shown to enhance nanoparticle transport across the intestinal epithelium. Here, different grafting strategies for non-peptidic ligands, e.g., peptidomimetics, lectin mimetics, sugars and vitamins, that are stable in the gastrointestinal tract are discussed. We demonstrate that the grafting of these non-peptidic ligands allows nanoparticles to be targeted to M cells, enterocytes, immune cells or L cells. We show that these grafted nanoparticles could be promising vehicles for oral vaccination by targeting M cells or for the delivery of therapeutic proteins. We suggest that targeting L cells could be useful for the treatment of type 2 diabetes or obesity.

Label-free electrochemical impedance spectroscopy biosensor for direct detection of cancer cells based on the interaction between carbohydrate and lectin.

A novel label-free electrochemical impedance spectroscopy (EIS) biosensor for direct cancer cell detection based on the interaction between carbohydrate and lectin has been developed with good sensitivity and selectivity. In the present work, concanavalin A (Con A), a mannose specific lectin, was immobilized on a gold disk electrode to fabricate the Con A sensor. This sensor was incubated with the cancer cell sample, and the binding of cancer cells with Con A resulted in a change of charge transfer resistance (Rct). EIS measurement was employed to measure the impedance change which reveals the concentration of cancer cells. This method has been successfully applied in human liver cancer cell Bel-7404 for direct and sensitive detection with a detection limit of 234cells/mL. This method could be extended to carry out multi-component diagnosis applications, thus providing enormous potential for applications of cancer monitoring and therapy.

The intestinal glucose-apelin cycle controls carbohydrate absorption in mice.

BACKGROUND & AIMS: Glucose is absorbed into intestine cells via the sodium glucose transporter 1 (SGLT-1) and glucose transporter 2 (GLUT2); various peptides and hormones control this process. Apelin is a peptide that regulates glucose homeostasis and is produced by proximal digestive cells; we studied whether glucose modulates apelin secretion by enterocytes and the effects of apelin on intestinal glucose absorption. METHODS: We characterized glucose-related luminal apelin secretion in vivo and ex vivo by mass spectroscopy and immunologic techniques. The effects of apelin on (14)C-labeled glucose transport were determined in jejunal loops and in mice following apelin gavage. We determined levels of GLUT2 and SGLT-1 proteins and phosphorylation of AMPKα2 by immunoblotting. The net effect of apelin on intestinal glucose transepithelial transport was determined in mice. RESULTS: Glucose stimulated luminal secretion of the pyroglutaminated apelin-13 isoform ([Pyr-1]-apelin-13) in the small intestine of mice. Apelin increased specific glucose flux through the gastric epithelial barrier in jejunal loops and in vivo following oral glucose administration. Conversely, pharmacologic apelin blockade in the intestine reduced the increased glycemia that occurs following oral glucose administration. Apelin activity was associated with phosphorylation of AMPKα2 and a rapid increase of the GLUT2/SGLT-1 protein ratio in the brush border membrane. CONCLUSIONS: Glucose amplifies its own transport from the intestinal lumen to the bloodstream by increasing luminal apelin secretion. In the lumen, active apelin regulates carbohydrate flux through enterocytes by promoting AMPKα2 phosphorylation and modifying the ratio of SGLT-1:GLUT2. The glucose-apelin cycle might be pharmacologically handled to regulate glucose absorption and assess better control of glucose homeostasis.

Self-assembled carbohydrate hydrogels for prolonged pain management.

CONTEXT: Nanoparticulate systems are new tools that promise a revolution in the field of drug delivery. Among their numerous benefits, polyelectrolyte complexes (PECs) have shown to provide a barrier to drug release. OBJECTIVE: In this study, PECs, in the form of self-assembled polymeric nanogels, have been studied as potential drug carriers of the freely soluble drug tramadol HCL trying to achieve a prolonged percutaneous permeation. METHODOLOGY: The hydrogels were subjected to swelling, rheology, release and permeation studies and were characterized by FTIR spectroscopy and scanning electron microscopy. RESULTS: P2 hydrogel composed of chitosan-carrageenan (1-1) PEC attained the most compromised rheological shear-thinning thixotropic behavior, good bioadhesive properties, the most retarded release and permeation with an f2 value <50 compared to chitosan hydrogel, altogether with non-irritancy to the skin. SEM photographs showed that P2 has spherical nanosized particles structure. CONCLUSION: This approach can provide us promising results for an around-the-clock analgesia with better safety and tolerability profile.

Novel multi-sugar assay for site-specific gastrointestinal permeability analysis: a randomized controlled crossover trial.

BACKGROUND & AIMS: Increased gastrointestinal (GI) permeability is an important hallmark of many conditions, potentially leading to antigen exposure and sepsis. Current permeability tests are hampered by analytical limitations. This study aims to compare the accuracy of our multi-sugar (MS) and the classical dual sugar (DS) test for detection of increased GI permeability. METHODS: Ten volunteers received permeability analysis using MS (1 g sucrose, lactulose, sucralose, erythritol, 0.5 g rhamnose in water) or DS (5 g lactulose, 0.5 g rhamnose), after indomethacin or placebo. Blood and urine were analyzed by isocratic LC-MS. RESULTS: MS testing revealed significantly elevated urinary lactulose/rhamnose (L/R) ratios after indomethacin, due to enhanced lactulose excretion (P < .01) and unaltered rhamnose excretion. The DS test showed increased L/R ratios, due to increased lactulose excretion and decreased rhamnose excretion (both P < .05). After indomethacin, plasma L/R increased in both assays (P < .05 and P < .01). Urinary and plasma L/R ratios correlated significantly. Indomethacin increased sucrose excretion and 0-1 h sucrose/rhamnose. Colon permeability was unchanged. CONCLUSIONS: Sensitive permeability analysis is feasible in plasma and urine using MS or DS test. In contrast to the DS test, monosaccharide excretion is not decreased by the MS test. In short, the MS test provides accurate, site-specific information on gastroduodenal, small, and large intestinal permeability. Registered at US National Library of Medicine (http://www.clinicaltrials.gov, NCT00943345).

Urinary recovery of orally administered chromium 51-labeled EDTA, lactulose, rhamnose, d-xylose, 3-O-methyl-d-glucose, and sucrose in healthy adult male Beagles.

Objective-To provide values for gastrointestinal permeability and absorptive function tests (GIPFTs) with chromium 51 ((51)Cr)-labeled EDTA, lactulose, rhamnose, d-xylose, 3-O-methyl-d-glucose, and sucrose in Beagles and to evaluate potential correlations between markers. Animals-19 healthy adult male Beagles. Procedures-A test solution containing 3.7 MBq of (51)Cr-labeled EDTA, 2 g of lactulose, 2 g of rhamnose, 2 g of d-xylose, 1 g of 3-O-methyl-d-glucose, and 8 g of sucrose was administered intragastrically to each dog. Urinary recovery of each probe was determined 6 hours after administration. Results-Mean ± SD (range) percentage urinary recovery was 6.3 ± 1.6% (4.3% to 9.7%) for (51)Cr-labeled EDTA, 3.3 ± 1.1% (1.7% to 5.3%) for lactulose, 25.5 ± 5.0% (16.7% to 36.9%) for rhamnose, and 58.8% ± 11.0% (40.1% to 87.8%) for 3-O-methyl-d-glucose. Mean (range) recovery ratio was 0.25 ± 0.06 (0.17 to 0.37) for (51)Cr-labeled EDTA to rhamnose, 0.13 ± 0.04 (0.08 to 0.23) for lactulose to rhamnose, and 0.73 ± 0.09 (0.60 to 0.90) for d-xylose to 3-O-methyl-d-glucose. Median (range) percentage urinary recovery was 40.3% (31.6% to 62.7%) for d-xylose and 0% (0% to 0.8%) for sucrose. Conclusions and Clinical Relevance-Reference values in healthy adult male Beagles for 6 of the most commonly used GIPFT markers were determined. The correlation between results for (51)Cr-labeled EDTA and lactulose was not as prominent as that reported for humans and cats; thus, investigators should be cautious in the use and interpretation of GIPFTs performed with sugar probes in dogs with suspected intestinal dysbiosis.

Enzymatic methods for glyco(diversification/randomization) of drugs and small molecules.

Glyco (randomization/diversification) is a term that encompasses strategies to diversify a core drug scaffold via enzymatic glycosylation to provide sets of analogs wherein the sole diversity element is a carbohydrate. This review covers the influence of glycosylation upon various drug properties, the classes of glycosyl-conjugating enzymes amenable to glyco(randomization/diversification) schemes, approaches to the synthesis of required substrates and specific examples of glycorandomized libraries utilizing both wild-type and engineered enzymes.