Pure redox-sensitive paclitaxel-maleimide prodrug nanoparticles: Endogenous albumin-induced size switching and improved antitumor efficiency

A commercial albumin-bound paclitaxel nano-formulation has been considered a gold standard against breast cancer. However, its application still restricted unfavorable pharmacokinetics and the immunogenicity of exogenous albumin carrier. Herein, we report an albumin-bound tumor redox-responsive paclitaxel prodrugs nano-delivery strategy. Using diverse linkages (thioether bond and disulfide bond), paclitaxel (PTX) was conjugated with an albumin-binding maleimide (MAL) functional group. These pure PTX prodrugs could self-assemble to form uniform and spherical nanoparticles (NPs) in aqueous solution without any excipients. By immediately binding to blood circulating albumin after intravenous administration, NPs are rapidly disintegrated into small prodrug/albumin nanoaggregates

Esferocitosis hereditaria: experiencia clínica y diagnóstica en Argentina / Hereditary spherocytosis: clinical and diagnostic experience in Argentina / Esferocitose hereditária: experiência clínica e diagnóstica na Argentina

Los objetivos del presente estudio fueron: a) Analizar las características demográficas y clínicas de nuestra población al diagnóstico; b) Evaluar si las pruebas más recientes presentan ventajas sobre las tradicionales; c) Confirmar la frecuencia de las distintas deficiencias de proteínas de membrana; d) Establecer la relación entre severidad y resultado de las pruebas o tipo de deficiencia. Se analizaron 359 individuos estudiados desde 2007, cuando se incorporaron criohemólisis hipertónica (CH), citometría de flujo con eosina-5'- maleimida (5'EMA-CF), FOE por citometría de flujo (FOE-CF) y electroforesis de proteínas de membrana (SDS-PAGE) al estudio de laboratorio clásico, fragilidad osmótica eritrocitaria (FOE) y autohemólisis (AH). Criterios diagnósticos para Esferocitosis Hereditaria (ESH): esferocitos en frotis y dos pruebas positivas. Se identificaron 174 pacientes con ESH y 22 portadores sanos. El 74,9% eran menores de 12 años. La transmisión fue dominante en el 83,1% de los casos. Tuvieron manifestaciones neonatales 89,1%. Las pruebas con mayor sensibilidad fueron CH (92,0%), FOE diferida (91,1%) y 5'EMA-CF (88,5%). En los 125 pacientes en quienes se realizaron CH, 5'EMA-CF y FOE-CF se observó que todos tenían al menos una prueba positiva; 122 (97,6%) tuvieron dos o tres positivas. Las deficiencias más frecuentes fueron ankirina y espectrina. No hubo diferencia en el resultado de las pruebas entre los subgrupos de severidad. Se concluye que las deficiencias más frecuentes en Argentina son ankirina y espectrina, coincidiendo con otras poblaciones latinoamericanas. El uso simultáneo de CH, 5'EMA-CF y FOE-CF permite diagnosticar más del 97% de los casos. La incidencia de manifestaciones neonatales es elevada.

The aims of this study were (a) to assess demographic and clinical aspects of our population at diagnosis; (b) to evaluate diagnostic accuracy of hypertonic cryohemolysis (HC), eosin-5'-maleimide flow cytometry (EMA-FC) and flow cytometric osmotic fragility (OF-FC) in relation to standard screening tests osmotic fragility (OF) and autohemolysis (AH); (c) to confirm the previously reported prevalence of membrane proteins defects; and (d) to assess the relationship between severity of anemia and results of confirmatory tests. Since 2007, the following tests were available in our laboratory: OF, AH, HC, EMA-FC, OF-FC and SDS-PAGE of membrane proteins. Diagnostic criteria for hereditary spherocytosis were spherocytes in blood smear plus ≥2 positive tests. Data from 359 individuals were analyzed: 174 HS patients and 22 silent carriers were detected; 74.9% of patients were less than 12 years old; 83.1% of them showed a dominant inheritance pattern; antecedent of neonatal jaundice/anemia was registered in 89.1%. Tests with higher sensitivity were: HC (92.0%), incubated OF (91.1%), and EMA-FC (88.5%). HC, EMA-FC and OF-FC were simultaneously performed on 125 patients: each of them had at least 1 positive test; 122 (97.6%) had 2 or 3 positive tests. Ankyrin and spectrin were the most frequently found protein deficiencies. Comparison of test results in relation to severity of anemia showed no difference between groups. It can be concluded that compared toother Latin American countries, ankyrin and spectrin were the most frequent protein deficiencies. Simultaneous performing of HC, EMA-FC and OF-FC enabled diagnosing HS in more than 97% of patients. A high incidence of neonatal jaundice/anemia was observed.

Os objetivos do presente estudo foram: a) analisar as características demográficas e clínicas de nossa população ao diagnóstico; b) Avaliar se as provas mais recentes apresentam vantagens sobre as tradicionais; c) Confirmar a frequência das diversas deficiências de proteínas de membrana; d) Establecer a relação entre severidade e resultado das provas ou tipo de deficiência. Foram analisados 359 indivíduos estudados desde 2007, quando se incorporaram crio-hemólise hipertônica (CH), citometria de fluxo com eosina-5'-maleimida (5'EMA-CF), FOE por citometria de fluxo (FOE-CF) e eletroforese de proteínas de membrana (SDS-PAGE) ao estudo de laboratório clássico - fragilidade osmótica eritrocitária (FOE) e auto-hemólise (AH). Critérios diagnósticos para ESH: esferócitos em esfregaço e duas provas positivas. Foram identificados 174 pacientes com ESH e 22 portadores sadios. 74,9% eram menores de 12 anos. A transmissão foi dominante em 83,1%. Tiveram manifestações neonatais 89,1%. As provas com maior sensibilidade foram CH (92,0%), FOE diferida (91,1%) e 5'EMA-CF (88,5%). Nos 125 pacientes aos quais lhes realizaram CH, 5'EMA-CF e FOE-CF se observou que todos tinham no mínimo uma prova positiva; 122 (97,6%) tiveram duas ou três positivas. As deficiências mais frequentes foram anquirina e espectrina. Não houve diferença no resultado das provas entre os subgrupos de severidade. Conclui-se que as deficiências mais frequentes na Argentina são anquirina e espectrina, as quais coincidem com outras populações latinoamericanas. O uso simultâneo de CH, 5'EMA-CF e FOE-CF permite diagnosticar mais de 97% dos casos. A incidência de manifestações neonatais é elevada.

Modification of mPEGylated novel bifunctional fusion protein GAD and its propenty / 中国药科大学学报

In order to solve the difficucties of renaturation and immunogenicity of new bifunctional fusion protein GAD,inclusion bodies of GAD were modified by PEG-maleimide.Conformational changes of the modified GAD were compared by circular dichroism and tryptophan fluorescence spectroscopy.The biological activity was verified by oral glucose tolerance test and lipid scavenging.The results showed that PEG-maleimide completed the specific-point modification of GAD,and improved its refolding efficiency.The secondary and tertiary structures of mPEGylated GAD were consistent with that of GAD.PEG-GAD has significant hypoglycemic and lipid-lowering effects (P ＜0.001) with longer half life in vivo and lower immunogenicity (P ＜0.01).This study provides effective strategies for the development of strongly hydrophobic peptide drugs.

Preparation of Norcantharidin Nano-micelle and Study on Its Antitumor Effect / 中国药房

OBJECTIVE:To prepare the norcantharidin (NCTD) nano-micelle and study its antitumor effect. METHODS:NCTD nano-micelle was self-formed in water using Triblock copolymers distearyl phosphatidylethanolamine-polyethylene glycol-ma-leimide;its shape was observed,the drug-loading rate,entrapment efficiency,particle size,Zeta potential were investigated. MTT was used to investigate the cell survival rate of human lung cancer A549 cells in negative control group (Phosphate buffer solu-tion),carrier group (blank nano-micelle),positive control group (NCTD APIs,5-320 μg/mL) and NCTD nano-micelle group (NCTD,5-320 μg/mL) after acting different time (24,48,72 h). Tumor nude mice were randomly divided into blank control group,NCTD injection group(1 mg/kg),NCTD low-dose,high-dose groups(0.5,1 mg/kg),6 in each group. All mice were in-travenously injected relevant medicines in tail,once a day,for 8 weeks. Tumor size was measured every week,and tumor quality was detected after the second day of finishing administration. RESULTS:NCTD nano-micelle was round,drug-loading rate was (2.82±0.05)%,entrapment efficiency was(83.67±1.78)%,particle size was(138.6±45.8)nm,Zeta potential was -(12.75± 0.34)mV(n=6). Cell survival rate of A549 cells in carrier group had no obvious changes,and was obviously decreased in posi-tive control group and NCTD nano-micelle group,which was positively correlated with concentration and time. And the decrease degree of cell survival rate in NCTD nano-micelle group was stronger than positive control group(P<0.01). Compared with blank control group,the tumor quality of mice in 3 administration groups was reduced (P<0.05),the reduction degree in NCTD na-no-micelle high-dose group was stronger than NCTD nano-micelle injection group (P<0.05). CONCLUSIONS:NCTD nano-mi-celle is successfully prepared,which has good in vitro and in vitro anti-tumor effect on A549 cells.

Correlation of the degree of band 3 protein absence on erythrocyte membrane by eosin-5′-maleimide binding test and clinical phenotype in hereditary spherocytosis / 中华血液学杂志

Objective@#To investigate the relationship between the eosin-5′-maleimide (EMA) binding test and the clinical severity of hereditary spherocytosis (HS).@*Methods@#A total of 258 un-splenectomize HS patients were consecutively enrolled. Correlation of hemoglobin concentration, hemolytic parameters, compensating erythropoiesis and the EMA binding test were evaluated.@*Results@#258 (128 male and 130 female) patients were included in this study, including 91 compensatory hemolysis patients, 53 patients with mild anemia, 78 patients with moderate anemia and 36 patients with severe anemia. The median age at diagnosis was 23 (2-70) years. The median decreased fluorescence intensity of EMA binding test was 29.97% (16.09%-47.34%) and the average intensity was (29.70±6.28) % of 258 HS patients. The decreased EMA binding fluorescence intensity correlated with MCV (r=-0.343, P<0.001) and MCHC (r=0.223, P<0.001). There was no relationship between EMA fluorescence intensity and absolute reticulocyte count (r=0.080, P=0.198) , reticulocyte percentile (r=-0.015, P=0.813) , IBIL levels (r=-0.009, P=0.902) , HGB levels (r=-0.067, P=0.280). Evaluated as a quartile variable, EMA fluorescence intensity was not correlated with anemia severity (C=0.150, P=0.746).@*Conclusion@#EMA binding test does not related to anemia levels and has no major clinical implications for disease severity in HS.

Isolation and identification of chemical constituents from Disporum cantoniense / 中草药

Objective: To study the chemical constituents from Disporum cantoniense. Methods: Various column chromatographic techniques were used to separate and purify the chemical constituents and their structures were elucidated by spectral ananlysis. Results: Sixteen compounds were isolated and identified as 3-maleimide-5-oxime (1), 4-methylene-5-oxopyrrolidine-2- carboxylic acid (2), thymine (3), adenosine (4), 5'-deoxy-5'-methylamino-adenosine (5), ethyl-α-L-rhamnose (6), bergenin (7), 4-hydroxy- 2-methoxyphenyl-6-deoxy-α-L-talopyranoside (8), (-)-epicatechin (9), (6R,9R)-roseoside (10), 3-(4-hydroxy-3,5-dimethoxyphenyl) propane-1,2-diol (11), 3-hydroxy-5-(p-hydroxyphenyl) pentanoic acid (12), 1-ribityl-2,3-diketo-1,2,3,4-tetrahydro-6,7-dimethyl-quinoxaline (13), (6S,9R)-vomifoliol (14), 1-(3,4-dihydroxyphenyl)-2-hydroxye-thanone (15), and 1,2-dihydroxy-1-(4-hydroxy-3,5-dimethoxyphenyl)- ethane (16). Conclusion: Compounds 1, 2, 5-9, and 12-16 are isolated from genus Disporum Salisb. for the first time, and compounds 1, 2, 5-10, and 12-16 are isolated from this plant for the first time.

Synthesis and screening of new maleimide derivatives as potential anti-tubercular agents.

In the present investigation a series of new maleimide derivatives were synthesized by reacting different anilines with maleic anhydride in presence of acetic anhydride and sodium acetate. The synthesized compounds were identified by using IR, 1H NMR and mass spectral data analysis. The preliminary in vitro antimicrobial activity was studied against S. aureus, E. coli and A. niger. Further, the synthesized compounds (PA1-PA15) were subjected to in vitro antitubercular activity against Mycobacterium tuberculosis H37Rv using MABA method. The compounds PA4 (MIC 6.25 μg/ml), PA8 (MIC 3.125 μg/ml), PA14 (MIC 3.125 μg/ml) showed significant inhibitory activity against M. tuberculosis H37Rv.

Isolation and Structure Determination of an Imidazo-pyrimidine, 5-Chlorocavernicolin, Maleimide oximes and Nucleosides from a Marine Sponge Extract

In a continuation of our studies to discover bioactive secondary metabolites from marine sources, we further investigated samples from a tryptamine and phenyl-alkane producing sponge, which resulted in the isolation of four uncommon small molecules and five nucleosides. Their structures were determined to be 7,8-dihydroimidazo[1,5-c]pyrimidin-5(6H)-one (1), 5-chlorocavernicolin (2), maleimide-5-oxime (3), 3-methylmaleimide-5-oxime (4), uridine (5), 2'-deoxyuridine (6), thymidine (7), adenine (8), and adenosine (9) by spectroscopic analyses. The isolated compounds were evaluated for inhibitory activity against soluble epoxide hydrolase (sEH) as well as the Wnt/beta-catenine signaling pathway.

Side-effects of protein kinase inhibitors on ion channels.

Protein kinases are one of the largest gene families and have regulatory roles in all aspects of eukaryotic cell function. Modulation of protein kinase activity is a desirable therapeutic approach for a number of human diseases associated with aberrant kinase activity, including cancers, arthritis and cardiovascular disorders. Several strategies have been used to develop specific and selective protein kinase modulators, primarily via inhibition of phosphorylation and down-regulation of kinase gene expression. These strategies are effective at regulating intracellular signalling pathways, but are unfortunately associated with several undesirable effects, particularly those that modulate ion channel function. In fact, the side-effects have precluded these inhibitors from being both useful experimental tools and therapeutically viable. This review focuses on the ion channel side-effects of several protein kinase inhibitors and specifically on those modulating K+, Na+ and Ca2+ ion channels. It is hoped that the information provided with a detailed summary in this review will assist the future development of novel specific and selective compounds targeting protein kinases both for experimental tools and for therapeutic approaches.

Anti-biofilm and anti-adherence activity of Glm-U inhibitors.

Background: Intravascular catheters and urinary catheters are an important source of hospital-acquired infections. Many microorganisms colonize indwelling catheters, including central venous catheters (CVCs) forming biofilms and cause infections that are difficult to treat. Although various methods have been employed to reduce biofilms, enzymes involved in bacterial cell wall synthesis could provide novel targets for the development of anti-biofilm agents. N-Acetylglucosamine-1-phosphate uridyltransferase (GlmU) is an essential enzyme in aminosugars metabolism and catalyzes the formation of uridine-diphospho-N-acetylglucosamine (UDP-GlcNAc), an important precursor in the peptidoglycan and lipopolysaccharide biosynthesis of Gram-positive and Gram-negative bacteria. Previous study has been conducted on the anti-biofilm effect of GlmU inhibitors such as N-ethyl maleimide (NEM) and NEM analogs along with a cationic polypeptide protamine sulfate (PS), which enhanced its anti-biofilm activity. AIM: The present study aimed at finding the effect of sub-inhibitory concentrations of N-ethyl maleimide (NEM) and protamine sulfate (PS) on the biofilms produced by Pseudomonas aeruginosa and Enterococcus spp. isolated from cases of catheter-associated UTI as well as Klebsiella pneumoniae and Staphylococcus aureus isolated from cases of catheter-related bloodstream infections (CRBSI). Materials and Methods: In order to enhance the activity of NEM and to develop a broad-spectrum anti-microbial composition, NEM (50 μg/ml) was combined with protamine sulfate (50 μg/ml) and tested for anti-biofilm activity using a standard quantitative biofilm assay method. Results and Conclusion: It was observed that NEM had no effect on the biofilm produced by Pseudomonas aeruginosa as well as by Enterococcus spp. NEM also caused a significant decrease in biofilm production by Staphylococcus aureus while it had no effect on the biofilm produced by Klebsiella pneumoniae. There was a significant synergistic inhibitory effect on Staphylococcus aureus and Enterococcus spp., whereas Pseudomonas aeruginosa and Klebsiella pneumoniae remained unaffected. Combination of GlmU inhibitor-plus-protamine sulfate failed to significantly reduce bacterial adherence of Pseudomonas aeruginosa and Klebsiella pneumoniae to catheter and cannula pieces, respectively. We found that the GlmU inhibitor was mainly effective in preventing the adherence and biofilm formation by gram-positive organisms. The combination of NEM and protamine sulfate may, therefore, be tried as anti-infective coatings for medical devices such as catheters and cannulas, and thus help in overcoming microbial resistance in the current era of increasing device-associated hospital infections.