Design and Modular Construction of a Polymeric Nanoparticle for Targeted Atherosclerosis Positron Emission Tomography Imaging: A Story of 25% <Superscript>64</Superscript>Cu-CANF-Comb

Purpose

To assess the physicochemical properties, pharmacokinetic profiles, and in vivo positron emission tomography (PET) imaging of natriuretic peptide clearance receptors (NPRC) expressed on atherosclerotic plaque of a series of targeted, polymeric nanoparticles.

Methods

To control their structure, non-targeted and targeted polymeric (comb) nanoparticles, conjugated with various amounts of c-atrial natriuretic peptide (CANF, 0, 5, 10 and 25%), were synthesized by controlled and modular chemistry. In vivo pharmacokinetic evaluation of these nanoparticles was performed in wildtype (WT) C57BL/6 mice after ⁶⁴Cu radiolabeling. PET imaging was performed on an apolipoprotein E–deficient (ApoE^?/?) mouse atherosclerosis model to assess the NPRC targeting efficiency. For comparison, an in vivo blood metabolism study was carried out in WT mice.

Results

All three ⁶⁴Cu-CANF-comb nanoparticles showed improved biodistribution profiles, including significantly reduced accumulation in both liver and spleen, compared to the non-targeted ⁶⁴Cu-comb. Of the three nanoparticles, the 25% ⁶⁴Cu-CANF-comb demonstrated the best NPRC targeting specificity and sensitivity in ApoE^?/? mice. Metabolism studies showed that the radiolabeled CANF-comb was stable in blood up to 9 days. Histopathological analyses confirmed the up-regulation of NPRC along the progression of atherosclerosis.

Conclusion

The 25% ⁶⁴Cu-CANF-comb demonstrated its potential as a PET imaging agent to detect atherosclerosis progression and status.

     

Bioactive flavanoids from <Emphasis Type="Italic">Glycosmis arborea</Emphasis>

Background

Glycosmis is a genus of evergreen glabrous shrub and distributed all over India. It possesses various medicinal properties and is used in indigenous medicine for cough, rheumatism, anemia, and jaundice. Glycosmis arborea is a rich source of alkaloids, terpenoids, coumarins, as well as flavonoids.

Results

The chemical investigation of methanol fraction of the leaves of G. arborea led to the isolation of one new flavone C-glycoside along with three known flavanoids, named as 5,7-dihydroxy-2-[4-hydroxy-3-(methoxy methyl) phenyl]-6-C-β-d-glucopyranosyl flavone (4), 5,7,4^′-trihydroxy-3^′-methoxy flavone (1), 5,4^′-dihydroxy-3^′-methoxy-7-O-β-d-glucupyranosyl flavanone (2), and 5,4^′-dihydroxy-3^′-methoxy-7-O-(α-l-rhamnosyl-(1?→6?)-β-d-glucopyranosyl) flavanone (3), respectively. The structures of all compounds were elucidated with the help of nuclear magnetic resonance spectrometry. Pure compounds and fractions were evaluated for pest antifeedant and antimicrobial activity.

Conclusion

Four compounds were isolated from the leaves of G. arborea. Among them, compound 4 showed significant antimicrobial activity.

     

Lower striatal dopamine transporter binding in neuroleptic-naive schizophrenic patients is not related to antipsychotic treatment but it suggests an illness trait

Introduction

Drug induced parkinsonism (DIP) is directly related to dopamine D2 receptor blockade. However, there are many references describing parkinsonian signs (PS) in naive-patients. In our previous study, we observed lower DAT binding in a group of first-episode schizophrenic patients after short-term treatment with risperidone, compared with age-matched healthy controls.

Aim

To clarify if DAT decrease could be an illness trait, excluding the effect of antipsychotics on DAT availability, and to determine whether DAT availability before treatment with antipsychotics may predict subsequent development of PS.

Materials and methods

A new series of 20 neuroleptic-naive schizophrenic patients and 15 healthy subjects was recruited. SPECT with [¹²³I] FP-CIT (DaTSCAN®) was performed before starting antipsychotics and after 4 weeks of treatment. PS and psychopathological status were assessed by the Simpson–Angus (SAS), CGI and PANSS scales. Quantitative analyses of SPECTs were performed using ROIs placed in the caudate, putamen and occipital cortex.

Results

Schizophrenic patients showed lower DAT binding compared with the healthy subjects at baseline (p<0.001) and after a 4-week-treatment period (p=0.001). Six out of eight schizophrenic patients of the DIP group were symptomatic for PS at baseline, in comparison to two out of 12 in the NoDIP group. Nonetheless, no differences were observed on DAT between DIP and NoDIP, neither at baseline (p=0.360) nor at endpoint (p=0.984). Finally, no differences between baseline–endpoint DAT binding were observed, neither in the DIP group (p=0.767) nor in the NoDIP group (p=0.093).

Conclusion

Our new series of first-episode naive-schizophrenic patients (1) points out DAT dysfunction as an illness trait due to the significantly lower DAT binding in schizophrenic patients in comparison to healthy subjects; (2) supports the results of other authors who describe PS in never-treated patients; (3) confirms that [¹²³I] FP-CIT does not allow us to predict which patients will develop parkinsonism due to the lack of differences between DIP and NoDIP patients; and (4) confirms a null effect of antipsychotics on DAT due to the lack of differences in [¹²³I] FP-CIT before and after a 4-week-treatment period.

     

<Emphasis Type="Italic">In Vivo</Emphasis> and <Emphasis Type="Italic">In Vitro</Emphasis> Evidence for Brain Uptake of 4-Phenylbutyrate by the Monocarboxylate Transporter 1 (MCT1)

Purpose

4-Phenylbutyrate (4-PBA) is expected to be a potential therapeutic for several neurodegenerative diseases. These activities require 4-PBA transport into the brain across the blood-brain barrier (BBB). The objective of the present study was to characterize the brain transport mechanism of 4-PBA through the BBB.

Methods

The brain transport of 4-PBA across the BBB was investigated following intravenous (IV) injection and internal carotid artery perfusion (ICAP) in vivo. The mechanism of transport was examined using TR-BBB cells, an in vitro model of the BBB.

Results

The volume of distribution (V_D) of 4-PBA by rat brain was about 7-fold greater than that of sucrose, a BBB impermeable vascular space marker, suggesting the blood-to-brain transport of 4-PBA through the BBB in the physiological state. [¹⁴C]4-PBA uptake by TR-BBB cells showed time-, pH- and concentration-dependence with a K _m of 13.4 mM at pH 7.4 and 3.22 mM at pH 6.0. The uptake was Na⁺ independent, and was significantly inhibited by alpha-cyano-4-hydroxycinnamate (a typical inhibitor for monocarboxylate transport), endogenous monocarboxylate compounds and monocarboxylic drugs. Lactate and valproate competitively inhibited [¹⁴C]4-PBA uptake with K _i value of 13.5 mM and 7.47 mM, respectively. These results indicate the role of monocarboxylate transporters (MCTs) in 4-PBA transport into the brain at the BBB. TR-BBB cells expressed mRNA of rMCT1, 2, and 4, especially, rMCT1 showed high mRNA expression level. In addition, [¹⁴C]4-PBA uptake was inhibited by rMCT1 specific small interfering RNA.

Conclusion

The transport mechanism of 4-PBA from blood to brain across the BBB likely involves MCT1.

     

Formulation and Evaluation of Chitosan-Based Buccal Bioadhesive Films of Zolmitriptan

Purpose

Therapeutic efficacy of zolmitriptan in oral therapy is primarily limited by the biopharmaceutical issues. The objective of this study is to design and optimize chitosan-based buccal bioadhesive system for the effective delivery of zolmitriptan in the treatment of migraine.

Methods

Factorial design (3²) is constructed and conducted in a fully randomized manner to study all nine possible experimental runs. The films were prepared by solvent casting method by varying the content of chitosan (X₁) and polyvinyl alcohol (X₂). The effect of these two independent variables on swelling index (Y1), percent drug release in 15 min (Y2) and 5 h (Y3), and mucoadhesive strength (Y4) of prepared films was evaluated.

Results

The physical and chemical characteristics displayed by the prepared films (F1–F9) were found to be optimal. It was observed that the factor X₁ has positive and X₂ has negative effect on response Y1. In contrast, factor X₁ showed negative effects on drug release at both time intervals (15 min and 5 h) while X₂ displayed positive responses for these variables (Y2 and Y3). However, the mucoadhesion increased with an increase in factor X₁ and decreased when the factor X₂ was increased. Indeed, the desirable characteristics exhibited by the film F7 are ideal for buccal application. Greater flux (63.93?±?12.51 μg/cm²/h) demonstrated in ex vivo studies substantiated the potential of optimized film to effectively deliver zolmitriptan across the buccal membrane.

Conclusions

This study concludes that the chitosan-based buccal film (F7) could be used in both prophylaxis and acute treatment of migraine, although need to be proved in vivo.

     

Removing of Benzo[<Emphasis Type="Italic">a</Emphasis>]pyrene using the Isolated Fungi from Petroleum-polluted Soils

Objective

Benzo[a]pyrene, belonging to polycyclic aromatic hydrocarbons, is one of the most important industrial pollutants. This research was aimed to evaluate some fungal strains, with petroleum removing potency, for degradation of BaP from BaP-polluted media and also evaluation of Enzyme activity and protein content in the fungi growing in BaP-polluted media.

Methods

In a field study seven fungal specie were isolated from Tehran oil refinery and cultured in potato dextrose agar (PDA) media containing 30, 60 and 90 (mg/kg) BaP for adaptation of the fungal strains. Removing of BaP was measured after 45 days growth of the fungal colonies under different concentrations of BaP pollution in PDA media and soil. Peroxidase and catalase activity, and protein content were compared in the fungi growing in BaP-polluted media and control ones.

Results

The results showed that all the isolated fungi were able to growth in the BaP containing media and could remove BaP from the media. The highest removal efficiency was determined for Fusarium acuminatum (93%). Similar data obtained when the fungus used for bioremediation of BaP-polluted soil (91%). Total protein content and enzymatic activity (Peroxidase and Catalase) were increased with increasing of BaP pollution. The highest catalase activity was measured in F. acuminatum growing in the media containing 90 mg/kg BaP (2.2×10^-2 unit/mg protein) and the highest (5× 10^-3 unit/mg protein) peroxidase activity for Alternaria alternata. Protein content in the fungi was increased with increasing of BaP pollution. In F. acuminatum, the lowest amount of total protein was observed in the control sample (1×10^-3 mg/g FW) and the highest amount was belonging to the group treated by 90 mg/kg BaP (7.5×10^-3 mg/g FW).

Conclusion

It concluded that F. acuminatum showed the highest catalase activity, highest total protein content and also the highest BaP removal efficiency from both BaP-polluted media and soils.

     

Radiofluorination and biological evaluation of <Emphasis Type="Italic">N</Emphasis>-aryl-oxadiazolyl-propionamides as potential radioligands for PET imaging of cannabinoid CB<Subscript>2</Subscript> receptors

Background

The level of expression of cannabinoid receptor type 2 (CB₂R) in healthy and diseased brain has not been fully elucidated. Therefore, there is a growing interest to assess the regional expression of CB₂R in the brain. Positron emission tomography (PET) is an imaging technique, which allows quantitative monitoring of very low amounts of radiolabelled compounds in living organisms at high temporal and spatial resolution and, thus, has been widely used as a diagnostic tool in nuclear medicine. Here, we report on the radiofluorination of N-aryl-oxadiazolyl-propionamides at two different positions in the lead structure and on the biological evaluation of the potential of the two tracers [¹⁸F]1 and [¹⁸F]2 as CB₂ receptor PET imaging agents.

Results

High binding affinity and specificity towards CB₂ receptors of the lead structure remained unaffected by the structural changes such as the insertion of the aliphatic and aromatic fluorine in the selected labelling sites of 1 and 2. Aliphatic and aromatic radiofluorinations were optimized, and [¹⁸F]1 and [¹⁸F]2 were achieved in radiochemical yields of ≥30% with radiochemical purities of ≥98% and specific activities of 250 to 450 GBq/μmol. Organ distribution studies in female CD1 mice revealed that both radiotracers cross the blood–brain barrier (BBB) but undergo strong peripheral metabolism. At 30 min after injection, unmetabolized [¹⁸F]1 and [¹⁸F]2 accounted for 60% and 2% as well as 68% and 88% of the total activity in the plasma and brain, respectively. The main radiometabolite of [¹⁸F]2 could be identified as the free acid [¹⁸F]10, which has no affinity towards the CB₁ and CB₂ receptors but can cross the BBB.

Conclusions

N-aryl-oxadiazolyl-propionamides can successfully be radiolabelled with ¹⁸F at different positions. Fluorine substitution at these positions did not affect affinity and specificity towards CB₂R. Despite a promising in vitro behavior, a rather rapid peripheral metabolism of [¹⁸F]1 and [¹⁸F]2 in mice and the generation of brain permeable radiometabolites hamper the application of these radiotracers in vivo. However, it is expected that future synthetic modification aiming at a replacement of metabolically susceptible structural elements of [¹⁸F]1 and [¹⁸F]2 will help to elucidate the potential of this class of compounds for CB₂R PET studies.

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Active cyamemazine metabolites in patients treated with cyamemazine (Tercian<Emphasis Type="Bold">®</Emphasis>): influence on cerebral dopamine D<Subscript>2</Subscript> and serotonin 5-HT<Subscript>2A</Subscript> receptor occupancy as measured by positron emission tomography (PET)

Rationale

Cyamemazine (Tercian®) is an antipsychotic agent blocking central dopamine D₂ receptors, which induces few extrapyramidal adverse effects, due to a potent antagonistic action at serotonin 5-HT_2A receptors. In vitro studies showed that the desmethyl metabolite of cyamemazine (N-desmethyl cyamemazine) has similar affinity for 5-HT_2A receptors as cyamemazine, whereas its D₂ receptor affinity is eight times lower (Benyamina et al. in Eur J Pharmacol 578(2–3):142–147, 2008). Moreover, cyamemazine sulfoxide showed modest affinity for 5-HT_2A receptors.

Objectives

The objective of this study is to measure steady-state plasma levels of N-desmethyl cyamemazine and cyamemazine sulfoxide in patients treated with clinically relevant doses of cyamemazine and correlate them with dopamine D₂ and serotonin 5-HT_2A receptor occupancies (RO) assessed by positron emission tomography (PET).

Methods

Eight patients received Tercian® 37.5, 75, 150, or 300 mg/day according to their symptoms. Dopamine D₂ and serotonin 5-HT_2A RO were assessed at steady-state cyamemazine plasma levels using [¹¹C]raclopride and [¹¹C]N-methyl-spiperone, respectively, for PET. Plasma levels of cyamemazine metabolites were determined using a validated high-performance liquid chromatography (PerkinElmer) associated with a mass spectrometry detection (API 365, PE SCIEX). The apparent equilibrium inhibition constant (K _i) was estimated by fitting RO with plasma levels of cyamemazine metabolites at the time of the PET scan.

Results

After 6 days of cyamemazine administration, plasma N-desmethyl cyamemazine reached steady-state levels at 2 to 12 times higher than those previously found for cyamemazine (Hode et al. in Psychopharmacology (Berl) 180:377–384, 2005). Plasma levels of N-desmethyl cyamemazine were closely related to striatal D₂ RO (r ²?=?0.942) and extrastriatal 5-HT_2A RO (r ²?=?0.901). The estimated K _i(app) value of N-desmethyl cyamemazine for striatal D₂ receptors was about fivefold higher than that for extrastriatal 5-HT_2A receptors (48.7 vs. 10.6 nM). Striatal D₂ RO increased with the plasma levels of N-desmethyl cyamemazine but remained below 75% even at its highest levels. At steady state, plasma cyamemazine sulfoxide levels were about double those of N-desmethyl cyamemazine. However, these cyamemazine sulfoxide levels should not contribute significantly to in vivo 5-HT_2A and D₂ receptor occupancy.

Conclusions

In patients orally given cyamemazine, N-desmethyl cyamemazine, but not cyamemazine sulfoxide, should significantly contribute to in vivo frontal 5-HT_2A and striatal D₂ receptor occupancy. The higher in vivo affinity of cyamemazine and its desmethyl metabolite for serotonin 5-HT_2A receptors compared with dopamine D₂ receptors should explain the low incidence of extrapyramidal adverse effects.

     

Inter-Subject Variability in OCT1 Activity in 27 Batches of Cryopreserved Human Hepatocytes and Association with OCT1 mRNA Expression and Genotype

Purpose

OCT1/3 (Organic Cation Transporter-1 and -3; SLC22A1/3) are transmembrane proteins localized at the basolateral membrane of hepatocytes. They mediate the uptake of cationic endogenous compounds and/or xenobiotics. The present study was set up to verify whether the previously observed variability in OCT activity in hepatocytes may be explained by inter-individual differences in OCT1/3 mRNA levels or OCT1 genotype.

Methods

Twenty-seven batches of cryopreserved human hepatocytes (male and female, age 24–88 y) were characterized for OCT activity, normalized OCT1/3 mRNA expression, and OCT1 genetic mutation. ASP⁺ (4-[4-(dimethylamino)styryl]-N-methylpyridinium iodide) was used as probe substrate.

Results

ASP⁺ uptake ranged between 75 ± 61 and 2531 ± 202 pmol/(min × million cells). The relative OCT1 and OCT3 mRNA expression ranged between 0.007–0.46 and 0.0002–0.005, respectively. The presence of one or two nonfunctional SLC22A1 alleles was observed in 13 batches and these exhibited significant (p = 0.04) association with OCT1 and OCT3 mRNA expression. However, direct association between genotype and OCT activity could not be established.

Conclusion

mRNA levels and genotype of OCT only partially explain inter-individual variability in OCT-mediated transport. Our findings illustrate the necessity of in vitro transporter activity profiling for better understanding of inter-individual drug disposition behavior.

     

Regulatory Variants Modulate Protein Kinase C α (<Emphasis Type="Italic">PRKCA</Emphasis>) Gene Expression in Human Heart

Purpose

Protein kinase C α (PRKCA) is involved in multiple functions and has been implicated in heart failure risks and treatment outcomes. This study aims to identify regulatory variants affecting PRKCA expression in human heart, and evaluate attributable risk of heart disease.

Methods

mRNA expression quantitative trait loci (eQTLs) were extracted from the Genotype and Tissue Expression Project (GTEx). Allelic mRNA ratios were measured in 51 human heart tissues to identify cis-acting regulatory variants. Potential regulatory regions were tested with luciferase reporter gene assays and further evaluated in GTEx and genome-wide association studies.

Results

Located in a region with robust enhancer activity in luciferase reporter assays, rs9909004 (T?>?C, minor allele frequency =0.47) resides in a haplotype displaying strong eQTLs for PRKCA in heart (p?=?1.2?×?10^?23). The minor C allele is associated with both decreased PRKCA mRNA expression and decreased risk of phenotypes characteristic of heart failure in GWAS analyses (QT interval p?=?3.0?×?10^?14). While rs9909004 is the likely regulatory variant, other variants in high linkage disequilibrium cannot be excluded. Distinct regulatory variants appear to affect expression in other tissues.

Conclusions

The haplotype carrying rs9909004 influences PRKCA expression in the heart and is associated with traits linked to heart failure, potentially affecting therapy of heart failure.

     

Enhanced Anti-Tumor Efficacy of Lipid-Modified Platinum Derivatives in Combination with <Emphasis Type="BoldItalic">Survivin</Emphasis> Silencing siRNA in Resistant Non-Small Cell Lung Cancer

Purpose

Cisplatin, is recognized as a first line therapeutic for the treatment of non-small cell lung cancer (NSCLC). Cisplatin resistance is identified as the most detrimental complication during treatment and has been associated with upregulation of several genes, such as the anti-apoptotic gene survivin. In this study, we have evaluated the cytotoxic activity of lipid (C6 and C8)-modified platinum compounds in combination with a survivin-silencing siRNA against cisplatin resistant tumors.

Methods

We synthesized and characterized several lipid-modified platinum compounds and evaluated their cytotoxic activity alone or in combination with survivin-silencing siRNA in vitro and in vivo against A549^DDP cells and in vivo in tumor xenograft model.

Results

The lipid-modified compounds exhibited significantly stronger cytotoxic activity in vitro compared to cisplatin, with CDDP-C6 and CDDP-C8 producing the most pronounced effect, in both A549 and A549^DDP cells. Pre-treatment of the A549^DDP cells with survivin-silencing siRNA enhanced the cytotoxic activity of these compounds. In vivo, the co-treatment of the survivin-silencing siRNA and CDDP-C8 produced the strongest tumor growth inhibition effect (64.5%, p?<?0.05) on a cancer mouse model of chemoresistant lung cancer. In contrast, cisplatin treatment exhibited no significant tumor growth inhibition (4.5%, no p).

Conclusions

Co-treatment of lipid-modified compounds and survivin-silencing siRNA can constitute a reliable alternative to cisplatin treatment for cisplatin-resistant lung tumors that merit further evaluation.

     

The effects of melatonin supplementation on inflammatory markers among patients with metabolic syndrome or related disorders: a systematic review and meta-analysis of randomized controlled trials

Objective

This systematic review and meta-analysis of randomized controlled trials (RCTs) was carried out to determine the effect of melatonin supplementation on the inflammatory markers among individuals with metabolic syndrome (MetS) and related disorders.

Methods

We searched the following databases up to March 2018: PubMed, MEDLINE, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials. Three reviewers independently assessed study eligibility, extracted data, and evaluated risk of bias of included primary studies. Statistical heterogeneity was assessed using Cochran’s Q test and I-square (I²) statistic. Data were pooled using the random effect model and standardized mean difference (SMD) was considered as the summary effect size.

Results

Six trials of 317 potential reports were identified to be suitable for our meta-analysis. The pooled results using random effects model indicated that melatonin supplementation significantly reduced C-reactive protein (CRP) (SMD?=???1.80; 95% CI ??3.27, ??0.32; P?=?0.01; I²: 95.2) and interleukin 6 (IL-6) concentrations (SMD?=???2.02; 95% CI ??3.57, ??0.47; P?=?0.01; I²: 91.2) among patients with MetS and related disorders; however, it did not affect tumor necrosis factor-α (TNF-α) concentrations (SMD?=???1.87; 95% CI ??3.81, 0.07; P?=?0.05; I²: 94.4).

Conclusions

In summary, the current meta-analysis showed the promising effect of melatonin administration on reducing CRP and IL-6, but not TNF-α levels among patients with MetS and related disorders. Additional prospective studies are recommended using higher supplementation doses and longer intervention period.

     

A new <Emphasis Type="BoldItalic">in vitro</Emphasis> lipid digestion – <Emphasis Type="BoldItalic">in vivo</Emphasis> absorption model to evaluate the mechanisms of drug absorption from lipid-based formulations

Purpose

In vitro lipid digestion models are commonly used to screen lipid-based formulations (LBF), but in vitro-in vivo correlations are in some cases unsuccessful. Here we enhance the scope of the lipid digestion test by incorporating an absorption ‘sink’ into the experimental model.

Methods

An in vitro model of lipid digestion was coupled directly to a single pass in situ intestinal perfusion experiment in an anaesthetised rat. The model allowed simultaneous real-time analysis of the digestion and absorption of LBFs of fenofibrate and was employed to evaluate the influence of formulation digestion, supersaturation and precipitation on drug absorption.

Results

Formulations containing higher quantities of co-solvent and surfactant resulted in higher supersaturation and more rapid drug precipitation in vitro when compared to those containing higher quantities of lipid. In contrast, when the same formulations were examined using the coupled in vitro lipid digestion – in vivo absorption model, drug flux into the mesenteric vein was similar regardless of in vitro formulation performance.

Conclusion

For some drugs, simple in vitro lipid digestion models may underestimate the potential for absorption from LBFs. Consistent with recent in vivo studies, drug absorption for rapidly absorbed drugs such as fenofibrate may occur even when drug precipitation is apparent during in vitro digestion.

     

Hyaluronic Acid Layer-By-Layer (LbL) Nanoparticles for Synergistic Chemo-Phototherapy

Purpose

The aim of this study was to design hyaluronic acid (HA) layer-by-layer (LbL) nanoparticles, which carried paclitaxel (PTX) and Indocyanine green (ICG) to both tumor cells and tumor associated cells to achieve synergistic chemo-photothermal therapeutic effect.

Methods

The LbL-engineered nanoparticles (PDIH) were prepared by dopamine self-polymerization on PTX nanocrystal to form thin, surface-adherent polydopamine (PDA) films, which subsequently absorbed ICG and HA. The tumor cell and tumor associated cell targeting and antitumor efficacy of PDIH were investigated both in vitro an in vivo using 4 T1 murine mammary cancer cell lines and mice bearing orthotopic 4 T1 breast tumor.

Results

PDIH presented a long-rod shape in TEM and showed enhanced photothermal effect and cytotoxicity upon NIR laser irradiation both in vitro and in vivo. PDIH also displayed high target ability to CD44 overexpressed tumor cells and tumor associated cells mediated by HA. In vivo antitumor study indicated that PDIH therapeutic strategy could achieve remarkable antitumor efficacy.

Conclusion

PDIH showed excellent tumor-targeting property and chemo-photothermal therapeutic efficacy.

     

Characterization of Temperature Profiles in Skin and Transdermal Delivery System When Exposed to Temperature Gradients <Emphasis Type="BoldItalic">In Vivo</Emphasis> and <Emphasis Type="BoldItalic">In Vitro</Emphasis>

Purpose

Performance of a transdermal delivery system (TDS) can be affected by exposure to elevated temperature, which can lead to unintended safety issues. This study investigated TDS and skin temperatures and their relationship in vivo, characterized the effective thermal resistance of skin, and identified the in vitro diffusion cell conditions that would correlate with in vivo observations.

Methods

Experiments were performed in humans and in Franz diffusion cells with human cadaver skin to record skin and TDS temperatures at room temperature and with exposure to a heat flux. Skin temperatures were regulated with two methods: a heating lamp in vivo and in vitro, or thermostatic control of the receiver chamber in vitro.

Results

In vivo basal skin temperatures beneath TDS at different anatomical sites were not statistically different. The maximum tolerable skin surface temperature was approximately 42–43°C in vivo. The temperature difference between skin surface and TDS surface increased with increasing temperature, or with increasing TDS thermal resistance in vivo and in vitro.

Conclusions

Based on the effective thermal resistance of skin in vivo and in vitro, the heating lamp method is an adequate in vitro method. However, the in vitro-in vivo correlation of temperature could be affected by the thermal boundary layer in the receiver chamber.

     

Exploration of Optimal Dosing Regimens of Haloperidol,a D<Subscript>2</Subscript> Antagonist, <Emphasis Type="Italic">via</Emphasis> Modeling and Simulation Analysis in a D<Subscript>2</Subscript> Receptor Occupancy Study

Purpose

To evaluate the potential usage of D₂ receptor occupancy (D2RO) measured by positron emission tomography (PET) in antipsychotic development.

Methods

In this randomized, parallel group study, eight healthy male volunteers received oral doses of 0.5 (n?=?3), 1 (n?=?2), or 3 mg (n?=?3) of haloperidol once daily for 7 days. PET’s were scanned before haloperidol, and on days 8, 12, with serial pharmacokinetic sampling on day 7. Pharmacokinetics and binding potential to D₂ receptor in putamen and caudate nucleus over time were analyzed using NONMEM, and simulations for the profiles of D2RO over time on various regimens of haloperidol were conducted to find the optimal dosing regimens.

Results

One compartment model with a saturable binding compartment, and inhibitory E_max model in the effect compartment best described the data. Plasma haloperidol concentrations at half-maximal inhibition were 0.791 and 0.650 ng/ml, in putamen and caudate nucleus. Simulation suggested haloperidol 2 mg every 12 h is near the optimal dose.

Conclusion

This study showed that sparse D2RO measurements in steady state pharmacodynamic design after multiple dosing could reveal the possibility of treatment effect of D₂ antagonist, and could identify the potential optimal doses for later clinical studies by modeling and simulation.

     

Reformulation of Fungizone by PEG-DSPE Micelles: Deaggregation and Detoxification of Amphotericin B

Purpose

Fungizone® (AmB-SD), amphotericin B solubilized by sodium deoxycholate, contains a highly aggregated form of the antifungal agent that causes dose-limiting renal toxicity. With the aim of reducing the formulation’s toxicity by co-delivering monomeric amphotericin B (AmB) and sodium supplementation, we deaggregated AmB-SD with FDA-approved excipient PEG-DSPE in 0.9% NaCl-USP. Herein, we describe a reformulated AmB-SD with PEG-DSPE micelles that results in a less toxic drug with maintained antifungal activity.

Methods

We compared the aggregation state and particle size of AmB-SD alone or combined with PEG-DSPE micelles. In vitro hemolytic activity and in vivo renal toxicity were measured to determine the toxicity of different formulations. In vitro antifungal assays were performed to determine differences in efficacy among formulations.

Results

PEG-DSPE micelles in saline deaggregated AmB-SD. Deaggregated AmB-SD exhibited significantly reduced in vitro and in vivo toxicity. In vitro antifungal studies showed no difference in minimum inhibitory and fungicidal concentrations of AmB-SD combined with PEG-DSPE relative to the drug alone.

Conclusions

Reformulation of AmB-SD with PEG-DSPE micelles in saline facilitates co-delivery of monomeric AmB and sodium supplementation, potentially reducing the dose-limiting nephrotoxicity of AmB-SD. Ease of preparation and commercially available components lead us to acknowledge its potential for clinical use.

     

The CYP2C19 ultra-rapid metabolizer genotype influences the pharmacokinetics of voriconazole in healthy male volunteers

Aim

To study the pharmacokinetic characteristics of voriconazole in healthy Chinese male volunteers in relation to cytochrome P450 (CYP) 2C19 genotype status, including ultra-rapid metabolizers (URMs), homozygous extensive metabolizers (EMs), and poor metabolizers (PMs).

Method

Twenty healthy Chinese male volunteers were recruited for the study. Of these, four were CYP2C19 heterozygous URMs (*1/*17), eight were CYP2C19 homozygous EMs (*1/*1), and eight were CYP2C19 PMs (*2/*2). After a single oral dose of 200 mg voriconazole, plasma concentrations of voriconazole were determined for a 24-h period by liquid chromatography–mass spectrometry/mass spectrometry.

Result

In Chinese male subjects, the allele frequencies of the CYP2C19*17 and CYP2C19*2 alleles were 0.64 and 35.6%, respectively, and both alleles were in Hardy–Weinberg equilibrium. The area under the concentration–time curve (AUC) from predose to 24 h (AUC_0–24) and from predose to infinity (AUC_0-∞), and apparent oral clearance (CL/F) of voriconazole were statistically different among all three genotypic groups (P?max) value of URMs also showed statistically significant differences from those of EMs and PMs (P?=?0.036 and P =?0.035, respectively). The elimination half-life (t_½) in URMs was 87% (P?=?0.58) of that in EMs and 51% (P=?0.002) of that in PMs.

Conclusion

Our data indicate that the presence of the CYP2C19*17 allele results in ultra-rapid metabolism of voriconazole after a single oral dose.

     

Efficacy of Nanostructures as Preservation Carriers of <Emphasis Type="Italic">Bacillus atrophaeus</Emphasis> in the Preparation of Sterilization Bioindicators

Purpose

The spores of Bacillus atrophaeus are used to monitor the efficacy of disinfection and sterilization processes, particularly in dry heat and ethylene oxide sterilization processes. The production process of biological sterilization indicators of this bacterium includes bacterial sporulation, which leads to a dormant structure with extreme resistance to heat stresses.

Methods

In this study, the efficacy of the application of nanomaterials as alternative carriers instead of regular paper strips in the recovery of spores and the stability of the prepared bioindicator was investigated. For this purpose, the structural types of nanomaterials applied as carriers on D values and spore absorption were evaluated and compared.

Results

The results suggest the nanomaterial’s potential to be used as the supports of bioindicators. Among the evaluated nanomaterials adsorbents, including nanocellulose, lignocellulose, chitin, gamma alumina and silica, silica and gamma alumina illustrated the highest spore absorption potency (10⁷ CFU/mL) and highest spore resistance by the D value of 6.5 min.

Conclusion

The results of this study suggest that nanomaterials can be a suitable replacement for conventional strips due to their higher perdurability.