Synthesis and Thrombogenicity Evaluation of Poly(3-methoxypropionic acid vinyl ester): A Candidate for Blood-Compatible Polymers.

A poly(vinyl acetate) derivative, poly(3-methoxypropionic acid vinyl ester) (PMePVE), was synthesized to develop a new candidate for blood compatible polymers. The monomer MePVE was synthesized by a simple two-step reaction, and then the MePVE was polymerized via free radical polymerization to obtain PMePVE. Human platelet adhesion tests were performed to evaluate the thrombogenicity, and the platelet adhesion was suppressed on the PMePVE-coated substrate. To determine the expression of the nonthrombogenicity of the PMePVE, the plasma protein adsorption and a conformationally altered state of fibrinogen were analyzed by a microBCA assay and enzyme-linked immunosorbent assay. The adsorption and denaturation of the plasma proteins were inhibited on the PMePVE; thus, PMePVE exhibited blood compatibility. A distinctive hydration water structure in the nonthrombogenic polymer, intermediate water (IW), was observed in the hydrated PMePVE by differential scanning calorimetry analysis. The nonthrombogenicity of PMePVE is considered to be brought about by the presence of IW.

Oxaprozin-Loaded Lipid Nanoparticles towards Overcoming NSAIDs Side-Effects.

PURPOSE: Nanostructured Lipid Carriers (NLCs) loading oxaprozin were developed to address an effective drug packaging and targeted delivery, improving the drug pharmacokinetics and pharmacodynamics properties and avoiding the local gastric side-effects. Macrophages actively phagocyte particles with sizes larger than 200 nm and, when activated, over-express folate beta receptors - features that in the case of this work constitute the basis for passive and active targeting strategies. METHODS: Two formulations containing oxaprozin were developed: NLCs with and without folate functionalization. In order to target the macrophages folate receptors, a DSPE-PEG2000-FA conjugate was synthesized and added to the NLCs. RESULTS: These formulations presented a relatively low polydispersity index (approximately 0.2) with mean diameters greater than 200 nm and zeta potential inferior to -40 mV. The encapsulation efficiency of the particles was superior to 95% and the loading capacity was of 9%, approximately. The formulations retained the oxaprozin release in simulated gastric fluid (only around 10%) promoting its release on simulated intestinal fluid. MTT and LDH assays revealed that the formulations only presented cytotoxicity in Caco-2 cells for oxaprozin concentrations superior to 100 µM. Permeability studies in Caco-2 cells shown that oxaprozin encapsulation did not interfered with oxaprozin permeability (around 0.8 × 10(-5) cm/s in simulated intestinal fluid and about 1.45 × 10(-5) cm/s in PBS). Moreover, in RAW 264.7 cells NLCs functionalization promoted an increased uptake over time mainly mediated by a caveolae uptake mechanism. CONCLUSIONS: The developed nanoparticles enclose a great potential for oxaprozin oral administration with significant less gastric side-effects.

Propionate and butyrate attenuate macrophage pyroptosis and osteoclastogenesis induced by CoCrMo alloy particles.

BACKGROUND: Wear particles-induced osteolysis is a major long-term complication after total joint arthroplasty. Up to now, there is no effective treatment for wear particles-induced osteolysis except for the revision surgery, which is a heavy psychological and economic burden to patients. A metabolite of gut microbiota, short chain fatty acids (SCFAs), has been reported to be beneficial for many chronic inflammatory diseases. This study aimed to investigate the therapeutic effect of SCFAs on osteolysis. METHODS: A model of inflammatory osteolysis was established by applying CoCrMo alloy particles to mouse calvarium. After two weeks of intervention, the anti-inflammatory effects of SCFAs on wear particle-induced osteolysis were evaluated by Micro-CT analysis and immunohistochemistry staining. In vitro study, lipopolysaccharide (LPS) primed bone marrow-derived macrophages (BMDMs) and Tohoku Hospital Pediatrics-1 (THP-1) macrophages were stimulated with CoCrMo particles to activate inflammasome in the presence of acetate (C2), propionate (C3), and butyrate (C4). Western blotting, Enzyme-linked immunosorbent assay, and immunofluorescence were used to detect the activation of NLRP3 inflammasome. The effects of SCFAs on osteoclasts were evaluate by qRT-PCR, Western blotting, immunofluorescence, and tartrate-resistant acid phosphatase (TRAP) staining. Additionally, histone deacetylase (HDAC) inhibitors, agonists of GPR41, GPR43, and GPR109A were applied to confirm the underlying mechanism of SCFAs on the inflammasome activation of macrophages and osteoclastogenesis. RESULTS: C3 and C4 but not C2 could alleviate wear particles-induced osteolysis with fewer bone erosion pits (P < 0.001), higher level of bone volume to tissue volume (BV/TV, P < 0.001), bone mineral density (BMD, P < 0.001), and a lower total porosity (P < 0.001). C3 and C4 prevented CoCrMo alloy particles-induced ASC speck formation and nucleation-induced oligomerization, suppressing the cleavage of caspase-1 (P < 0.05) and IL-1ß (P < 0.05) stimulated by CoCrMo alloy particles. C3 and C4 also inhibited the generation of Gasdermin D-N-terminal fragment (GSDMD-NT) to regulate pyroptosis. Besides, C3 and C4 have a negative impact on osteoclast differentiation (P < 0.05) and its function (P < 0.05), affecting the podosome arrangement and morphologically normal podosome belts formation. CONCLUSION: Our work showed that C3 and C4 are qualified candidates for the treatment of wear particle-induced osteolysis.

A thromboxane A2/prostaglandin H2 receptor antagonist (S18886) shows high antithrombotic efficacy in an experimental model of stent-induced thrombosis.

Acute thrombosis is a threat in patients undergoing percutaneous coronary intervention with stent implantation. Our objective was to determine if stent-induced thrombus formation could be inhibited by oral treatment with a thromboxane A(2)/prostaglandin H(2) receptor antagonist (TPr; S18886) as an alternative to standard therapy. Pigs were allocated in the following treatment (p.o) groups: I) clopidogrel (CLOP); II) ASA; III) S18886; IV) ASA+CLOP; and V) placebo-control. Damaged vessel was placed in the Badimon chamber containing a stent and perfused at 212/s. Antithrombotic effects were assessed as (111)In-platelet deposition (PD) in two series (60 and 180 min after drug intake). Fibrin(ogen) deposition, light transmittance aggregometry (LTA; collagen, U46619, and ADP), and bleeding time (BT) were also evaluated. After 60 min S18886 reduced PD < or =48%, 40%, and 35% vs placebo, CLOP-, and ASA-treated animals, respectively (P < 0.05), while ASA+CLOP showed a 58% reduction versus placebo (P < 0.01). After 3 hours, ASA+CLOP decreased PD by 55%, S18886 by 40%, CLOP alone by 28% (P < 0.05), and ASA showed no inhibition versus placebo. Similar effects were found in S18886- and ASA+CLOP-treated animals at both times. Fibrin(ogen) deposition followed the same pattern. Collagen-induced LTA was significantly reduced by ASA, ASA+CLOP, and S18886; S18886 abolished U46619-induced LTA; and, CLOP +/- ASA reduced ADP-induced LTA in a time-dependent manner. TPr blockade did not prolong BT, whereas CLOP +/- ASA significantly did (P < 0.0001). In conclusion, blockade of the TPr provided a fast and potent platelet inhibitory effect in a porcine model of in-stent thrombosis comparable to that of blocking both the ADP receptor and cyclooxygenase activation; in addition, TPr provided a more favorable bleeding risk profile.

Acute NSAID-related transmural duodenitis and extensive duodenal ulceration.

BACKGROUND: A 40-year-old previously healthy white man presented to the emergency department at American University of Beirut Medical Center, Beirut, Lebanon, with severe upper abdominal pain of 36-hour duration. The pain started a few hours after the intake of a single tablet of tiaprofenic acid and became more intense after the intake of another tablet 24 hours later. He had no other symptoms. He had no prior upper gastrointestinal (GI) symptoms, ulcer disease, steroidal or nonsteroidal anti-inflammatory drug use, or ethanol intake. Physical examination revealed mild upper abdominal tenderness. Complete blood count, amylase, lipase, and liver function tests were unremarkable. Computed tomography of the abdomen showed marked thickening of the duodenal wall with surrounding mesenteric streaking. Upper GI endoscopy revealed extensive ulceration involving the duodenal bulb, apex, and proximal D2, as well as a few gastric erosions. Histopathologic examination of duodenal biopsy samples showed extensive epithelial cell necrosis and infiltration of the lamina propria with neutrophils and eosinophils. The patient responded well to rabeprazole 20 mg BID and remains well 5 months later. METHODS: We performed a literature search of PubMed for all English-language articles published between January 1970 and present (June 2007) using the key words tiaprofenic acid, nonsteroidal anti-inflammatory drugs, NSAID, duodenitis, duodenal erosion, duodenal ulcer, gastritis, gastric erosion, gastric ulcer, or peptic ulcer. We reviewed all randomized controlled trials involving NSAIDs found using PubMed, with a focus on their GI adverse effects. RESULTS: Based on the PubMed search, there were no published reports of acute transmural duodenitis and complicated duodenal ulcers associated with short-term exposure to tiaprofenic acid or other NSAIDs. The Naranjo adverse drug reaction (ADR) probability scale was used and a score of 6 was obtained, indicating a probable ADR from tiaprofenic acid use. CONCLUSION: We report a patient who developed symptomatic severe transmural duodenitis and periduodenal mesenteric streaking, consistent with a complicated ulcer, probably associated with very short-term exposure to tiaprofenic acid.

In vitro, ex vivo and in vivo characterization of PLGA nanoparticles loading pranoprofen for ocular administration.

Pranoprofen (PF) is a NSAID considered as a safe anti-inflammatory treatment for strabismus and/or cataract surgery. The drug has been formulated in poly (lactic/glycolic) acid (PLGA) nanoparticles (PF-F1NPs with cPF 1.5mg/mL, PF-F2NPs with cPF 1mg/mL) produced by solvent displacement technique and tested the in vitro cytotoxicity, ex vivo corneal permeation, in vivo ocular tolerance and in vivo anti-inflammatory efficacy of PF-F1NPs, PF-F2NPs, in comparison to eye drops conventional dosage form (Oftalar(®), PF 1mg/mL) and free drug solution (PF dissolved in PBS, 1.5mg/mL). The mean particle size of both formulations was around 350nm, with polydispersity index below 0.1, and a net negative charge of -7.41mV and -8.5mV for PF-F1NPs and PF-F2NPs, respectively. Y-79 human retinoblastoma cell line was used to evaluate the cytotoxicity of PF-F1NPs and PF-F2NPs, which were compared to blank NPs and free drug solution (PF dissolved in PBS, 1.5mg/mL). Concentrations up to 75µg/mL exhibited no toxicity to Y-79 cells, whereas at 150µg/mL a decrease of about 80% on the cell viability was observed after exposing the cells to PF-F1NPs. When treating the Y-79 cells with concentrations of PF-F2NPs between 1µg/mL to 100µg/mL, the cell viability was similar to control values after 24h and 48h of exposure. An ex vivo corneal permeation study was carried out in New Zealand rabbits. A very similar profile has been observed for the permeation of PF through the cornea when administered as eye drops and as free drug solution, which was kept much lower in comparison to PF-NPs formulations. The permeated amount of PF from the PF-F1NPs was slightly smaller than from PF-F2NPs, attributed to the increase of viscosity of the formulations with the increase of cPVA concentration. New Zealand white rabbits were also used to evaluate the irritancy of PF-F1NPs and PF-F2NPs, which demonstrated to be well-tolerated to the eye (i.e. the mean total score (MTS) was 0). PF-F2NPs exhibited the highest QP (amounts of PF permeated in the cornea) and significantly reduced the ocular edema compared to the tested formulations. The QR (amounts of PF retained in the cornea) of the PF-F1NPs was greater than that obtained for PF-F2NPs.

Candoxatril, an orally active neutral endopeptidase inhibitor, raises plasma atrial natriuretic factor and is natriuretic in essential hypertension.

OBJECTIVE: Candoxatril (UK79,300) is an orally available inhibitor of the neutral endopeptidase (E.C.3.4.24.11) which degrades atrial natriuretic factor (ANF). This study was designed to establish initial safety and efficacy data in essential hypertension for this novel class of drug. DESIGN: A prospective, double-blind, placebo-controlled, single-dose comparison of candoxatril with placebo in a crossover manner. Three doses of candoxatril (10, 50 and 200 mg) were used, with four subjects at each dose level. SETTING: The Medical Research Council Blood Pressure Unit, Western Infirmary, Glasgow, UK (a hospital clinical research unit). PATIENTS: Twelve patients with untreated essential hypertension. Diastolic blood pressure was greater than 95 mmHg on three separate occasions before entry to the study. INTERVENTION: Candoxatril or matching placebo was administered orally in the fasting state. Serial measurements of urinary volume and electrolyte excretion were taken (on each hour, urine volume was replaced with an equivalent volume of water by mouth). Blood pressure and heart rate were recorded for 12 h after drug administration and serial blood samples were taken for measurement of plasma ANF and neurohormone concentrations. MAIN OUTCOME MEASURES: Urine volume and electrolyte concentration; blood pressure; heart rate; plasma atrial natriuretic factor. RESULTS: Plasma ANF concentrations rose significantly in all patients within 2 h of candoxatril administration compared with placebo although peak and integrated ANF levels were similar at all three doses. A significant natriuresis was only seen after 200 mg candoxatril, with a greater cumulative urine sodium excretion over 12 h compared with placebo; this was associated with a greater diuresis over 12 h compared with placebo. After a single oral dose of candoxatril, blood pressure and heart rate remained unchanged. CONCLUSIONS: Candoxatril in a single dose caused no adverse effects in essential hypertension. The drug caused a rise in basal ANF levels at all doses, but natriuresis was only seen with the highest dose used. No change in blood pressure was recorded after acute dosing, and the results of chronic studies with this compound are awaited. Oral inhibitors of ANF degradation may have therapeutic potential in cardiovascular disorders.

Gingival inflammation induced by food and short-chain carboxylic acids.

Earlier studies in our laboratories demonstrated that particles of a number of snack foods that are retained on the dentition accumulate fermentable sugars and short-chain carboxylic acids (SCCA; acetic, formic, lactic, and propionic) to different degrees. The present study was undertaken to test the hypothesis that the accumulated SCCA can induce a gingival inflammatory response. Five periodontally and medically healthy subjects were given portions of plain doughnuts (high SCCA levels) or oatmeal cookie (low SCCA), or had the SCCA applied directly to the gingival margins of designated teeth. Subjects were given wax to chew, or nothing, as controls. Inflammation was assessed by measurements of subgingival temperature, flow rates of gingival crevicular fluid (GCF), and neutrophil emigration into GCF. Subgingival temperatures of the maxillary gingiva rose by 1.32 +/- 0.30 degrees C (mean +/- SE) 5 min after the subjects consumed the doughnuts and remained elevated for at least 1 hr. These values were significantly higher than those obtained from subjects after ingestion of oatmeal cookies (0.63 +/- 0.17 degree C; p < 0.01), consistent with the low levels of SCCA in the retained cookie particles. Wax chewing elicited a similar response, indicating a masticatory effect on the gingiva. Gingival temperatures in the unchallenged controls remained unchanged. Neutrophil emigration into the GCF was significantly elevated in subjects after doughnut consumption. Rinses with a solution of SCCA, or application of the SCCA to the gingiva, also brought about significant elevations in subgingival temperature and neutrophil emigration. The findings describe the inflammatory effects of food ingestion on the gingiva of healthy human subjects, and support the hypothesis that SCCA in the particles of retained food are at least partly responsible for the observed responses.

Analgesic efficacy and safety of Fenbufen following surgical removal of a lower wisdom tooth: a comparison with acetylsalicylic acid and placebo.

In a double-blind clinical trial a new, non-steroidal anti-inflammatory agent with analgesic properties, Fenbufen, was compared to acetylsalicylic acid (ASA) and placebo. Six hundred (600) out-patients, following surgical removal of an impacted lower wisdom tooth, were divided into three groups and randomly given either Fenbufen (500 mg capsules), ASA (750 mg capsules), or placebo. One capsule was taken immediately after the surgical procedure, followed by another capsule every 6 hours. The duration of treatment was 24 hours. Thus, a total of 4 capsules were taken. Self-evaluation forms were provided to the patients and were returned to the investigators the following day. The results were statistically analyzed. Both Fenbufen and ASA were statistically superior (p less than or equal to 0.01) to placebo in relieving pain. A comparison of the Fenbufen and ASA groups demonstrated a statistically significant (p less than or equal to 0.05) superiority for Fenbufen in relieving pain. Also sleep was less disturbed in the Fenbufen group. Side-effects reported were few, minor in character, and fewer in number in the Fenbufen group.

Type IIa hyperlipoproteinaemia. An evaluation of four therapeutic regimens.

The cholesterol-lowering effect of clofibrate (Ciba-SU13437) cholestyramine and the combination of clofibrate and cholestyramine is studied in 19 subjects with type lla hyperlipoproteinaemia, over a 20-week period. Each regimen is evaluated in terms of total cholesterol-lowering effect, cholesterol-lowering effect at 4, 8 and 16 weeks of therapy, and the incidence of side-effects. Cholestyramine is identified as the agent of choice in the management of this disorder and recommendations for its optimal utilisation are put forward.

Short-chain carboxylic-acid-stimulated, PMN-mediated gingival inflammation.

This communication reviews the effects of short-chain carboxylic acids on human cells of importance to the periodontium. The central hypothesis is that these acids can alter both cell function and gene expression, and thus contribute to the initiation and prolongation of gingival inflammation. Short-chain carboxylic acids [CH3-(CH2)x-COOH, x < 3] are metabolic intermediates with a broad range of apparently paradoxical biological effects. For example, lactic acid (CH3-CHOH-COOH), a 3-carbon alpha-hydroxy-substituted acid, is widely recognized for its cariogenicity. Lactic acid, however, also occurs in tropical fruits, and is the active ingredient in a variety of anti-wrinkle creams developed by dermatologists. In marked contrast, the unsubstituted 3-carbon propionic acid (CH3-CH2-COOH) is used as a food preservative and is the active principle for one class of non-steroidal anti-inflammatory agents. Interestingly, the addition of one carbon to propionic acid dramatically changes the biological effects. The unsubstituted 4-carbon butyric acid (CH3-CH2-CH2-COOH) is used by hematologists as a de-differentiating agent for the treatment of sickle cell anemia, but by oncologists as a differentiating agent for cancer chemotherapy. Finally, acting either individually or in concert, these acids can increase vascular dilation. Clearly, these acids, while metabolically derived, have a number of very divergent activities which are cell-type-specific (Fig. 1). It may be telling that periodontal bacteria produce these acids in millimolar concentrations, and that these bacteria can be characterized by their acid production profiles. It is no less interesting that these acids occur in the gingival crevices of human subjects with severe periodontal disease at millimolar levels which are > 10-fold higher than those found in mildly diseased subjects, and are undetectable in healthy subjects. Further, when applied directly to healthy human gingiva, short-chain carboxylic acids stimulate a gingival inflammatory response and inflammatory cytokine release. At the cellular level, these acids inhibit proliferation of gingival epithelial and endothelial cells, and inhibit leukocyte apoptosis and function, but can stimulate leukocyte cytokine release. At the molecular level, these acids can stimulate neutrophil gene transcription, translation, and protein expression. Thus, the likelihood is high that these acids, in addition to their cariogenic activity, can promote and prolong gingival inflammation. Our challenge will be to identify the cell or cells of the periodontium which respond to short-chain carboxylic acids, to delineate their responses and the molecular mechanism(s) of these effects, and to categorize the aspects of the inflammatory components which damage and those which protect the host. With this information, it may be possible to begin to rationally identify and test pharmaceutical agents which diminish the harmful aspects, while enhancing the beneficial components, of the inflammatory response.