Dried Blood Spots as Matrix for Evaluation of Valproate Levels and the Immediate and Delayed Metabolomic Changes Induced by Single Valproate Dose Treatment.

The immediate and delayed metabolic changes in rats treated with valproate (VPA), a drug used for the treatment of epilepsy, were profiled. An established approach using dried blood spots (DBS) as sample matrices for gas chromatography/mass spectrometry-based metabolomics profiling was modified using double solvents in the extraction of analytes. With the modified method, some of the previously undetectable metabolites were recovered and subtle differences in the metabolic changes upon exposure to a single dose of VPA between males and female rats were identified. In male rats, changes in 2-hydroxybutyric acid, pipecolic acid, tetratriacontane and stearic acid were found between the control and treatment groups at various time points from 2.5 h up to 24 h. In contrast, such differences were not observed in female rats, which could be caused by the vast inter-individual variations in metabolite levels within the female group. Based on the measured DBS drug concentrations, clearance and apparent volume of distribution of VPA were estimated and the values were found to be comparable to those estimated previously from full blood drug concentrations. The current study indicated that DBS is a powerful tool to monitor drug levels and metabolic changes in response to drug treatment.

Investigating PEGDA and GelMA Microgel Models for Sustained 3D Heterotypic Dermal Papilla and Keratinocyte Co-Cultures.

Hair follicle morphogenesis is heavily dependent on reciprocal, sequential, and epithelial-mesenchymal interaction (EMI) between epidermal stem cells and the specialized cells of the underlying mesenchyme, which aggregate to form the dermal condensate (DC) and will later become the dermal papilla (DP). Similar models were developed with a co-culture of keratinocytes and DP cells. Previous studies have demonstrated that co-culture with keratinocytes maintains the in vivo characteristics of the DP. However, it is often challenging to develop three-dimensional (3D) DP and keratinocyte co-culture models for long term in vitro studies, due to the poor intercellular adherence between keratinocytes. Keratinocytes exhibit exfoliative behavior, and the integrity of the DP and keratinocyte co-cultured spheroids cannot be maintained over prolonged culture. Short durations of culture are unable to sufficiently allow the differentiation and re-programming of the keratinocytes into hair follicular fate by the DP. In this study, we explored a microgel array approach fabricated with two different hydrogel systems. Using poly (ethylene glycol) diacrylate (PEGDA) and gelatin methacrylate (GelMA), we compare their effects on maintaining the integrity of the cultures and their expression of important genes responsible for hair follicle morphogenesis, namely Wnt10A, Wnt10B, and Shh, over prolonged duration. We discovered that low attachment surfaces such as PEGDA result in the exfoliation of keratinocytes and were not suitable for long-term culture. GelMA, on the hand, was able to sustain the integrity of co-cultures and showed higher expression of the morphogens overtime.

Metabonomic profiling of bladder cancer.

Early diagnosis and life-long surveillance are clinically important to improve the long-term survival of bladder cancer patients. Currently, a noninvasive biomarker that is as sensitive and specific as cystoscopy in detecting bladder tumors is lacking. Metabonomics is a complementary approach for identifying perturbed metabolic pathways in bladder cancer. Significant progress has been made using modern metabonomic techniques to characterize and distinguish bladder cancer patients from control subjects, identify marker metabolites, and shed insights on the disease biology and potential therapeutic targets. With its rapid development, metabonomics has the potential to impact the clinical management of bladder cancer patients in the future by revolutionizing the diagnosis and life-long surveillance strategies and stratifying patients for diagnostic, surgical, and therapeutic clinical trials. An introduction to metabonomics, typical metabonomic workflow, and critical evaluation of metabonomic investigations in identifying biomarkers for the diagnosis of bladder cancer are presented.

Pharmacokinetic-pharmacodynamic analysis of spiroindolone analogs and KAE609 in a murine malaria model.

Limited information is available on the pharmacokinetic (PK) and pharmacodynamic (PD) parameters driving the efficacy of antimalarial drugs. Our objective in this study was to determine dose-response relationships of a panel of related spiroindolone analogs and identify the PK-PD index that correlates best with the efficacy of KAE609, a selected class representative. The dose-response efficacy studies were conducted in the Plasmodium berghei murine malaria model, and the relationship between dose and efficacy (i.e., reduction in parasitemia) was examined. All spiroindolone analogs studied displayed a maximum reduction in parasitemia, with 90% effective dose (ED90) values ranging between 6 and 38 mg/kg of body weight. Further, dose fractionation studies were conducted for KAE609, and the relationship between PK-PD indices and efficacy was analyzed. The PK-PD indices were calculated using the in vitro potency against P. berghei (2× the 99% inhibitory concentration [IC99]) as a threshold (TRE). The percentage of the time in which KAE609 plasma concentrations remained at >2× the IC99 within 48 h (%T>TRE) and the area under the concentration-time curve from 0 to 48 h (AUC0-48)/TRE ratio correlated well with parasite reduction (R2=0.97 and 0.95, respectively) but less so for the maximum concentration of drug in serum (Cmax)/TRE ratio (R2=0.88). The present results suggest that for KAE609 and, supposedly, for its analogs, the dosing regimens covering a T>TRE of 100%, AUC0-48/TRE ratio of 587, and a Cmax/TRE ratio of 30 are likely to result in the maximum reduction in parasitemia in the P. berghei malaria mouse model. This information could be used to prioritize analogs within the same class of compounds and contribute to the design of efficacy studies, thereby facilitating early drug discovery and lead optimization programs.

Comprehensive physicochemical, pharmacokinetic and activity profiling of anti-TB agents.

OBJECTIVES: The discovery and development of TB drugs has met limited success, with two new drugs approved over the last 40 years. Part of the difficulty resides in the lack of well-established in vitro or in vivo targets of potency and physicochemical and pharmacokinetic parameters. In an attempt to benchmark and compare such properties for anti-TB agents, we have experimentally determined and compiled these parameters for 36 anti-TB compounds, using standardized and centralized assays, thus ensuring direct comparability across drugs and drug classes. METHODS: Potency parameters included growth inhibition, cidal activity against growing and non-growing bacteria and activity against intracellular mycobacteria. Pharmacokinetic parameters included basic physicochemical properties, solubility, permeability and metabolic stability. We then attempted to establish correlations between physicochemical, in vitro and in vivo pharmacokinetic and pharmacodynamic indices to tentatively inform future drug discovery efforts. RESULTS: Two-thirds of the compounds tested showed bactericidal and intramacrophage activity. Most compounds exhibited favourable solubility, permeability and metabolic stability in standard in vitro pharmacokinetic assays. An analysis of human pharmacokinetic parameters revealed associations between lipophilicity and volume of distribution, clearance, plasma protein binding and oral bioavailability. Not surprisingly, most compounds with favourable pharmacokinetic properties complied with Lipinski's rule of five. CONCLUSIONS: However, most attempts to detect in vitro-in vivo correlations were unsuccessful, emphasizing the challenges of anti-TB drug discovery. The objective of this work is to provide a reference dataset for the TB drug discovery community with a focus on comparative in vitro potency and pharmacokinetics.

Urinary metabotyping of bladder cancer using two-dimensional gas chromatography time-of-flight mass spectrometry.

Cystoscopy is the gold standard clinical diagnosis of human bladder cancer (BC). As cystoscopy is expensive and invasive, it compromises patients' compliance toward surveillance screening and challenges the detection of recurrent BC. Therefore, the development of a noninvasive method for the diagnosis and surveillance of BC and the elucidation of BC progression become pertinent. In this study, urine samples from 38 BC patients and 61 non-BC controls were subjected to urinary metabotyping using two-dimensional gas chromatography time-of-flight mass spectrometry (GC×GC-TOFMS). Subsequent to data preprocessing and chemometric analysis, the orthogonal partial least-squares discriminant analysis (OPLS-DA, R2X=0.278, R2Y=0.904 and Q2Y (cumulative)=0.398) model was validated using permutation tests and receiver operating characteristic (ROC) analysis. Marker metabolites were further screened from the OPLS-DA model using statistical tests. GC×GC-TOFMS urinary metabotyping demonstrated 100% specificity and 71% sensitivity in detecting BC, while 100% specificity and 46% sensitivity were observed via cytology. In addition, the model revealed 46 metabolites that characterize human BC. Among the perturbed metabolic pathways, our clinical finding on the alteration of the tryptophan-quinolinic metabolic axis in BC suggested the potential roles of kynurenine in the malignancy and therapy of BC. In conclusion, global urinary metabotyping holds potential for the noninvasive diagnosis and surveillance of BC in clinics. In addition, perturbed metabolic pathways gleaned from urinary metabotyping shed new and established insights on the biology of human BC.

An automated Pearson's correlation change classification (APC3) approach for GC/MS metabonomic data using total ion chromatograms (TICs).

A fully automated and computationally efficient Pearson's correlation change classification (APC3) approach is proposed and shown to have overall comparable performance with both an average accuracy and an average AUC of 0.89 ± 0.08 but is 3.9 to 7 times faster, easier to use and have low outlier susceptibility in contrast to other dimensional reduction and classification combinations using only the total ion chromatogram (TIC) intensities of GC/MS data. The use of only the TIC permits the possible application of APC3 to other metabonomic data such as LC/MS TICs or NMR spectra. A RapidMiner implementation is available for download at http://padel.nus.edu.sg/software/padelapc3.

Developing a nomogram for dose individualization of phenytoin in Asian pediatric patients derived from population pharmacokinetic modeling of saturable pharmacokinetic profiles of the drug.

BACKGROUND: A population pharmacokinetic model for phenytoin in Asian pediatric patients was developed to determine the influence of concurrent medications, patient demographics, and blood biochemistry on the pharmacokinetic profile of phenytoin. METHODS: Retrospective clinical data were obtained from 66 patients (age, 1-16 years) for the determination of pharmacokinetic parameters of phenytoin using WinNonmix. Data from 49 patients (74.2%) were allocated in the "index" group, and the other 17 patients (25.8%) in the "validation" group. Models were compared by final log likelihood, mean error as a measure of bias, and root-mean-squared error as a measure of precision. RESULTS: The Michaelis-Menten constant (km) and volume of distribution (V) were fixed at 9.08 mg/L and 1.23 L/kg, respectively. The saturated elimination rate (V × Vmax) of phenytoin was then found to be 0.525 mg/kg per hour (352.9 4 mg/d for a 28.0 kg individual). Patients' body surface area (in square meter) and catalytic activities of liver enzymes aspartate aminotransferase (U/L) and alkaline phosphatase (U/L) appeared to have significant correlation with Vmax, whereas coadministrating drugs with phenytoin did not yield any significant effect. The final model for the saturated elimination rate was (Equation is included in full-text article.) In validation of the final model, the mean error was found to be -0.805 (95% confidence interval, -3.67 to 2.06), and the root-mean-squared error was 7.92 (95% confidence interval, 3.41-12.43). CONCLUSIONS: The obtained results indicated the need to consider patients' body surface area and the catalytic activities of liver enzymes aspartate aminotransferase and alkaline phosphatase when dosing phenytoin. Based on the population pharmacokinetic parameters, a nomogram was subsequently developed for dose individualization of phenytoin in Asian pediatric patients.

Percutaneous temporary aortic valve: a proof-of-concept animal model.

BACKGROUND AND AIM OF THE STUDY: An early prototype of a temporary aortic valve (TAV) catheter system was evaluated for its potential to serve as an integrated device for aortic valve intervention and replacement. The prototype consisted of two essential components: a central catheter for the delivery of aortic valve interventional tools (valve debulking, resection, replacement); and a balloon-inflatable temporary valve for hemodynamic support when the native aortic valve is removed. After valve replacement, the TAV catheter system is designed to be readily withdrawn from the subject. METHODS: Individual aspects of both components of the prototype were examined in experiments with four pigs. The central catheter was used to deliver a self-expanding stent for native aortic valve ablation to create acute severe aortic insufficiency (AI). The balloon-TAV was deployed in the proximal aorta to control the induced AI. Electrocardiographic (ECG), cardiac output (CO), pulmonary wedge pressure (PWP), left ventricular (LV) pressure, and aortic pressure proximal and distal from the TAV were recorded. RESULTS: The central catheter was successful in delivering and deploying the valve ablation stent at the annulus to create massive AI; the LV diastolic pressure was increased from 12.6 +/- 1.1 to 32.4 +/- 2.0 mmHg (p < 0.001) with valve ablation. The deployed TAV in the proximal aorta led to a re-narrowing of the distal pulse pressure with a drop in the LV diastolic pressure to 21.5 +/- 1.5 mmHg (p < 0.001). During TAV support, some PWP lowering and a CO rise occurred, but these did not achieve statistical significance; no significant acute ECG changes were noted. CONCLUSION: In this early prototype, the TAV catheter system demonstrated the potential to serve as an integrated device for both aortic valve modification and replacement.

The histone deacetylase inhibitors MS-275 and SAHA suppress the p38 mitogen-activated protein kinase signaling pathway and chemotaxis in rheumatoid arthritic synovial fibroblastic E11 cells.

MS-275 (entinostat) and SAHA (vorinostat), two histone deacetylase (HDAC) inhibitors currently in oncological trials, have displayed potent anti-rheumatic activities in rodent models of rheumatoid arthritis (RA). To further elucidate their anti-inflammatory mechanisms, the impact of MS-275 and SAHA on the p38 mitogen-activated protein kinase (MAPK) signaling pathway and chemotaxis was assessed in human rheumatoid arthritic synovial fibroblastic E11 cells. MS-275 and SAHA significantly suppressed the expression of p38α  MAPK, but induced the expression of MAPK phosphatase-1 (MKP-1), an endogenous suppressor of p38α  in E11 cells. At the same time, the association between p38α and MKP-1 was up-regulated and consequently, the activation (phosphorylation) of p38α  was inhibited. Moreover, MS-275 and SAHA suppressed granulocyte chemotactic protein-2 (GCP-2), monocyte chemotactic protein-2 (MCP-2) and macrophage migration inhibitory factor (MIF) in E11 cells in a concentration-dependent manner. Subsequently, E11-driven migration of THP-1 and U937 monocytes was inhibited. In summary, suppression of the p38 MAPK signaling pathway and chemotaxis appear to be important anti-rheumatic mechanisms of action of these HDAC inhibitors.

Metabonomic profiling of TASTPM transgenic Alzheimer's disease mouse model.

Identification of molecular mechanisms underlying early stage Alzheimer's disease (AD) is important for the development of new therapies against and diagnosis of AD. In this study, nontargeted metabonomics of TASTPM transgenic AD mice was performed. The metabolic profiles of both brain and plasma of TASTPM mice were characterized using gas chromatography-mass spectrometry and compared to those of wild-type C57BL/6J mice. TASTPM mice were metabolically distinct compared to wild-type mice (Q2Y=0.587 and 0.766 for PLS-DA models derived from brain and plasma, respectively). A number of metabolites were found to be perturbed in TASTPM mice in both brain (D-fructose, L-valine, L-serine, L-threonine, zymosterol) and plasma (D-glucose, D-galactose, linoleic acid, arachidonic acid, palmitic acid and D-gluconic acid). In addition, enzyme immunoassay confirmed that selected endogenous steroids were significantly perturbed in brain (androstenedione and 17-OH-progesterone) and plasma (cortisol and testosterone) of TASTPM mice. Ingenuity pathway analysis revealed that perturbations related to amino acid metabolism (brain), steroid biosynthesis (brain), linoleic acid metabolism (plasma) and energy metabolism (plasma) accounted for the differentiation of TASTPM and wild-type mice. Our results provided insights on the pathogenesis of APP-induced AD and reinforced the role of TASTPM in drug and biomarker development.

A retrospective study on the usage of antiepileptic drugs in Asian children from 2000 to 2009 in the largest pediatric hospital in Singapore.

PURPOSE: In light of the increasing usage of the newer antiepileptic drugs (AEDs) in other countries, we reviewed the prescribing pattern of AEDs in Singapore over the last 10 years (2000-2009). METHODS: A retrospective review of pharmacy dispensing records solicited from the only children's hospital in Singapore was performed to analyze the trend in AEDs prescribing in the last 10 years. We also examined the correlation between the serum concentrations of valproic acid (VPA), the most-prescribed AED, and seizure control. Descriptive and inferential statistical analyses were then performed on the findings. RESULTS: A total of 41 671 prescriptions on AEDs were retrieved and analyzed. Despite the introduction of the second-generation AEDs, the first generation AEDs still dominate epilepsy treatment in Asian children, with VPA being the mostly prescribed AED (about 40% of the total AEDs usage). The majority of patients (62.8%) were on monotherapy. The mean VPA serum concentration in patients with good seizure control was 68.6 µg/ml (SD = 26.4 µg/ml; range = 12.2-138.0 µg/ml), which was statistically higher than the mean VPA concentration of 57.7 µg/ml (SD = 27.1 µg/ml; range = 11.1-149.0 µg/ml) in patients with poor seizure control (p < 0.0001). CONCLUSION: With VPA being the most prescribed AED in our clinical practice, and the finding in this study that with careful classification of the patients' condition, serum concentrations of VPA generally correlate well with the seizure control, the correct dose titration of VPA with therapeutic drug monitoring is still of paramount importance.

A novel dextran-oleate-cRGDfK conjugate for self-assembly of nanodrug.

We report a novel synthetic biocompatible material: a conjugate with a fatty acid-substituted dextran decorated with cRGDfK peptide, which was used as a stable coating material instead of the conventional poly(ethylene glycol) for nanodrug preparation. This novel dextran-oleate-cRGDfK conjugate (DO-cRGDfk) could self-assemble into a micellar structure in aqueous solution, and was used as a surfactant to formulate nanodrug with poly(d,l-lactic-co-glycolic) acid as matrix to encapsulate paclitaxel with high drug-loading efficiency. The conjugate allowed the fabrication of nanodrug with a targeting moiety on its surface in a simple and robust step. The resultant nanoparticles could induce cellular apoptosis more effectively than that of the commercial paclitaxel formulation, Taxol. Thus, DO-cRGDfk could be used as an alternative to poly(ethylene glycol) as a biocompatible surface coating polymeric material for nanoparticle preparation. FROM THE CLINICAL EDITOR: The authors describe a novel synthetic biocompatible conjugate, which consists of a fatty acid-substituted dextran decorated with cRGDfK peptide. This conjugate was used as a stable coating material for nanodrug preparation, and can be used in place of conventional PEG.

Evaluation of dried blood spots as sample matrix for gas chromatography/mass spectrometry based metabolomic profiling.

We propose using dried blood spots (DBS) as sample matrix for gas chromatography/mass spectrometry (GC/MS) based metabolomic profiling for the benefits of higher sample stability, more convenient sample acquisition with DBS, higher analyte separation power, and more readily biomarker identification with GC/MS. To establish this proposition, the metabolomic profiles generated from DBS were compared with that obtained from the conventional whole blood and plasma matrixes and also with dried plasma spots (DPS) as another covariate control. Our findings indicated that whole blood produced the most number of detectable markers (866), whereas DPS yielded the least number (614). DBS and plasma matrix, on the other hand, produced the most similar numbers of detectable (695 vs 749) and identifiable markers (137 vs 147, matching with Fiehn library). From the analysis of the DBS and plasma metabolomic profiles, it was concluded that when l-lysine 2, iminodiacetic acid 2, dl-threo-beta-hydroxyaspartic acid, citric acid, or adenosine-5-monophosphate 2 are not involved as markers, DBS could be a suitable substitute for plasma for metabolomic profiling.

Nanoparticulate delivery system targeted to tumor neovasculature for combined anticancer and antiangiogenesis therapy.

PURPOSE: Herein, we designed a nanoparticulate combined delivery system decorated on the surface with RGD peptide, and encapsulating paclitaxel (PTX) and combretastatin A4 (CA4) as the respective anticancer and antiangiogenesis agent in the nanoparticle. METHODS: PTX and CA4 were co-encapsulated into the biocompatible PLGA, followed by solvent evaporation to form solid nanoparticle. The cRGDfK peptide was then conjugated onto the nanoparticle surface with EDC/NHS chemistry. RESULTS: The developed nanoparticles (NPs) were found uniform in size and well dispersed in buffers. The cellular uptake of such NPs could be efficiently detected as early as 20 min after incubation. In 24-h incubation, the encapsulated PTX could induce caspase 3/7-dependent apoptosis at 50 nM, whereas the CA4-loaded NPs could disrupt tubulin structure at 2.5 µM. The targeted dual drug-loaded nanoparticle achieved significant tumor growth suppression in vivo compared to the control from day 8 (P < 0.05). Histological results revealed that the targeted dual drug nanoparticle led to dramatic tumor vasculature disruption, significant cancer cell apoptosis and cell proliferation inhibition in the mouse model. CONCLUSION: These findings indicate that the targeted dual drug nanoparticulate delivery system encompassing both antiangiogenesis and anticancer effects can be a potential candidate in cancer therapy.

Extraction of ketamine from urine using a miniature silica monolithic cartridge followed by quantification with liquid chromatography tandem mass spectrometry (LC-MS/MS).

The high surface area monolith with reactive hydroxyl group on its surface enables it to function as a miniature solid-phase extraction (SPE) cartridge in size of 1 cm in diameter and 0.5 cm in length. The prepared silica monolith was characterized by Brunauer-Emmett-Teller method, scanning electron microscopy, X-ray diffraction and Fourier transform infrared (FTIR) spectroscopy. Ketamine was selected as model analyte to validate the extraction efficiency of the prepared cartridge. The extracted ketamine from urine sample was quantitated by liquid chromatography tandem mass spectrometry (LC-MS/MS) using positive electrospray ionization. The limit of detection and quantification for ketamine was found to be 0.5 and 1.6 ng/mL, respectively. The analysis exhibited linearity in the range of 10-500 ng/mL with coefficient of correlation >0.99. The recovery was found to be in the range of 89-107% with relative standard deviation (RSD) less than 10%. The prepared cartridge was found robust in extracting ketamine efficiently and repeatedly without any significant deterioration in its performance. Moreover, the batch-to-batch variations in the performance of the prepared cartridges in terms of % ion suppression of the extracts and recoveries of samples were small, suggesting the consistency in the properties of the monolith.

Percutaneous aortic valve replacement. Part 3: Balloon counterpulsation of a novel temporary aortic valve.

A previously published two-part study described an engineering design of a percutaneous aortic valve (PAV) replacement system, which utilizes a novel temporary aortic valve (TAV) support to improve procedural outcomes and safety. Conceptually, this investigational approach can promote accurate PAV placement, procedural hemodynamic stability, smaller catheter delivery system, reduction in PAV regurgitation, reduction in conduction and vascular complications. The balloon TAV can potentially facilitate the PAV replacement procedure by serving as the patient's surrogate aortic valve while the native valve is pretreated and replaced. The original TAV is designed to function with an effective aortic stenosis and insufficiency in moderate ranges, which lessens from the patient's more critical valve condition, should be well tolerated when the native valve becomes nonfunctional during the replacement process. Further optimization of the TAV's hemodynamic profile could further improve the system's overall performance and enhance the realization of a truly minimally invasive, cath lab-based PAV replacement procedure comparable to that of percutaneous coronary intervention. This study explores design permutations from the original published TAV, including varying the number of balloons and adding balloon counterpulsations, to improve upon its hemodynamic profile to better serve as the patient's surrogate valve and the overall PAV replacement procedure.

Noninvasive urinary metabonomic diagnosis of human bladder cancer.

Cystoscopy is considered the gold standard for the clinical diagnosis of human bladder cancer (BC). As cystoscopy is expensive and invasive, it may compromise patients' compliance and account for the failure in detecting recurrent BC in some patients. In this paper, we investigated the role of urinary metabonomics in the diagnosis of human BC. Gas chromatography/time-of-flight mass spectrometry was applied for the urinary metabolic profiling of 24 BC patients and 51 non-BC controls. The acquired data were analyzed using multivariate principal component analysis followed by orthogonal partial least-squares discriminant analysis (OPLS-DA). Model validity was verified using permutation tests and receiver operating characteristic (ROC) analysis. BC patients were clearly distinguished from non-BC subjects based on their global urinary metabolic profiles (OPLS-DA, 4 latent variables, R(2)X = 0.420, R(2)Y = 0.912 and Q(2) (cumulative) = 0.245; ROC AUC of 0.90; 15 marker metabolites). One-hundred percent sensitivity in detecting BC was observed using urinary metabonomics versus 33% sensitivity achieved by urinary cytology. Additionally, urinary metabonomics exhibited potential in the staging and grading of bladder tumors. In summary, urinary metabonomics is amenable for the noninvasive diagnosis of human BC.

Self-assembled core-shell vascular-targeted nanocapsules for temporal antivasculature and anticancer activities.

A biocompatible core-shell nanocapsule is fabricated to target tumor vascular endothelial cells where it releases anti-angiogenesis and anticancer drugs sequentially. The fabrication of the core-shell nanocapsule is accomplished through a robust double self-assembly procedure: the hydrophobic polymeric core is first precipitated to encapsulate a poorly water-soluble anticancer drug paclitaxel (PTX) with the assistance of lecithin and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[carboxy(polyethylene glycol)2000] (DSPE-PEG) self-assembled in aqueous phase. Another lipid layer self-assembled around the above hydrophobic core is formed to load a second drug combretastatin A4 (CA4) as a vascular disrupting agent in the lipid layer. The lipid layer serves both as a depot for CA4, as well as a molecular fence to sustain the release of PTX from the polymeric core. The size of the resultant nanocapsule can be fine-turned by slightly adjusting the preparation conditions from several tens of nanometer to one hundred nanometers. The uptake of this nanocapsule by human umbilical vein endothelial cells (HUVEC) is efficient, and the two loaded drugs maintain their respective therapeutic potency. The time-dependent sequential release of these two drugs over a time difference of 36 h results in temporal ablation of endothelial cells and cancer cells. This self-assembled delivery system could serve as a universal prototype that can be applied for other combinatorial temporal drug delivery.

Histone deacetylase inhibitors MS-275 and SAHA induced growth arrest and suppressed lipopolysaccharide-stimulated NF-kappaB p65 nuclear accumulation in human rheumatoid arthritis synovial fibroblastic E11 cells.

OBJECTIVES: MS-275 and suberoylanilide hydroxamic acid (SAHA) are histone deacetylase (HDAC) inhibitors currently tested in oncology trials. They have also been found to display potent anti-rheumatic activities in rodent models for RA. However, the anti-rheumatic mechanisms of action remain unknown. The study was carried out with the intent of determining the anti-inflammatory and anti-rheumatic mechanisms of the HDAC inhibitors. METHODS: In this study, the anti-rheumatic mechanisms of MS-275 and SAHA were investigated in several cell culture models. RESULTS: MS-275 and SAHA inhibited human RA synovial fibroblastic E11 cell proliferation in a non-cytotoxic manner. The anti-proliferative activities were associated with G(0)/G(1) phase arrest and induction of cyclin-dependent kinase inhibitor p21. In addition, MS-275 and SAHA suppressed lipopolysaccharide (LPS)-induced NF-kappaB p65 nuclear accumulation, IL-6, IL-18 and nitric oxide (NO) secretion as well as down-regulated pro-angiogenic VEGF and MMP-2 and MMP-9 production in E11 cells at sub-micromolar levels. At similar concentrations, MS-275 and SAHA suppressed LPS-induced NF-kappaB p65 nuclear accumulation and IL-1beta, IL-6, IL-18 and TNF-alpha secretion in THP-1 monocytic cells. Moreover, NO secretion in RAW264.7 macrophage cells was also inhibited. CONCLUSIONS: In summary, MS-275 and SAHA exhibited their anti-rheumatic activities by growth arrest in RA synovial fibroblasts, inhibition of pro-inflammatory cytokines and NO, as well as down-regulation in angiogenesis and MMPs. Their anti-rheumatic activities may be mediated through induction of p21 and suppression of NF-kappaB nuclear accumulation.