Preparation of Effective and Safe Gene Carriers by Grafting Alkyl Chains to Generation 5 Polypropyleneimine

Gene therapy is a novel method to treat a variety of diseases including genetic disorders and cancer. Nonviral gene carriers have now gained considerable attention as gene carrier systems. Polyamidoamine (PAMAM) and polypropyleneimine (PPI) are the two most widely used denderimers in gene delivery studies. The aim of the current study was to investigate the effects of modification of generation 5 polypropyleneimine (G5 PPI) dendrimers with alkanoate groups as hydrophobic moieties on DNA transfection and cytotoxicity. Six, 10, and 16 carbon derivatives of bromoalkanoic acids were conjugated onto PPI with 10%, 30%, and 50% of surface amine grafting. Ethidium bromide exclusion assay results proved the ability of modified carriers to condense DNA. Transfection assay showed higher DNA delivery potential for 30% and 50% grafting with decanoate moieties compared to native G5 PPI and Superfect^TM. 3-(4,5-Dimethylthiazol-2-yl)-2,5-di phenyltetrazolium bromide (MTT) and apoptosis experiments showed lower toxicity for modified carriers compared to unmodified PPI. The hemolytic effect of grafted carriers was not significantly different from G5 PPI. Size and zeta potential measurements revealed that polyplex size was less than 200 nm and electrical charges were in the range 14–25 mV. The hydrophobic modifications improved transfection activity and toxicity of G5 PPI without negatively affecting hemocompatibility. These modified carriers are therefore promising candidates for further in vivo investigations.KEY WORDS: gene delivery, hydrophobic modification, nonviral vector, polypropyleneimine, transfection     

Association Between Trace Element Status and Depression in HTLV-1-Infected Patients: a Retrospective Cohort Study

Depression and Anxiety are two important public health problems that are known to be associated with viral infections. The association between the intake of nutrients such as zinc and copper with symptoms of depression has been studied previously. The aim of the current study was to investigate the association between depression with human T cell lymphotropic virus type 1 (HTLV-1) infection and serum content of zinc and copper in a large Iranian population cohort. The study population consisted of 279 HTLV-1-positive patients who were identified after recruitment as part of a large cohort study: the Mashhad Stroke and Heart Association Disorder (MASHAD) study. They were divided into two groups of diagnosed with or without depression based on their symptoms. Serum zinc and copper levels of all subjects were measured using the flame atomic absorption spectrometry. The population sample comprised of 279 individuals infected with HTLV-1 of whom 192 (68.8%) were women. The mean serum zinc in the group with and without depression was 78.69 ± 13.79 μg/dl and 86.87 ± 19.44 μg/dl, respectively (p < 0.001). Also, the serum copper level was higher in the depressive group (116.75 ± 39.56) than in the non-depressive group (104.76 ± 30.77) (p 0.004). The association between serum zinc and copper with depression in HTLV-1-infected patients which was shown in this study could be considered in the treatment strategies in these patients.

     

Conversion of antibacterial quinolone drug levofloxacin to potent cytotoxic agents

Levofloxacin, the optical S-(-) isomer of ofloxacin, is a broad-spectrum antibacterial agent widely used to control various infections caused by Gram-positive and Gram-negative bacteria. While the COOH group is necessary for antibacterial activity, its modification can offer anticancer activity to the fluoroquinolone framework. Therefore, several levofloxacin carboxamides 11a-j and 12 containing 5-substituted-1,3,4-thiadiazole residue were synthesized and screened in vitro for their anticancer activity. The in vitro MTT viability assay revealed that the most compounds had significant activity against cancer cells MCF-7, A549, and SKOV3. In particular, the 3-chloro- and 4-fluoro- benzyl derivatives ( 11b and 11h ), with IC₅₀ values of 1.69–4.76 μM were as potent as or better than doxorubicin. It should be noted that the mother quinolone levofloxacin showed no activity on the tested cancer cell lines. The SAR analysis demonstrated that the 3-chloro or 4-fluoro substituent on the S-benzyl moiety had positive effect on the activity. Further in vitro evaluations of the most promising compounds 11b and 11h by flow cytometric analysis and comet test revealed the ability of compounds in the induction of apoptosis and blockage of the cell proliferation at the G1-phase by nuclear fragmentation and DNA degradation in cancer cells. The obtained results demonstrated that the alteration of 6-COOH functional group in the levofloxacin structure and conjugation with a proper heterocyclic pharmacophore is a good strategy to obtain new anticancer agents.     

Age-specific reference intervals for routine biochemical parameters in healthy neonates,infants, and young children in Iran

Age and sex need to be considered in the establishment of reference intervals (RIs), especially in early life when there are dynamic physiological changes. Since data for important biomarkers in healthy neonates and infants are limited, particularly in Iranian populations, we have determined age-specific RIs for 7 laboratory biochemical parameters. This cross-sectional study comprised a total of 344 paediatric participants (males: 158, females: 186) between the ages of 3 days and 30 months (mean age: 12.91 ± 7.15 months). Serum levels of creatinine, urea, uric acid, calcium, phosphate, vitamin D and high-sensitivity C-reactive protein (hs-CRP) were measured using an Alpha classic-AT plus auto-analyser. We determined age-specific RIs using CLSI Ep28-A3 and C28-A3 guidelines. No sex partitioning was required for any of the biomarkers. Age partitioning was required for kidney function tests and phosphate. The serum concentration of urea and creatinine increased with age, while phosphate and uric acid decreased with age. Age partitioning was not required for serum calcium, vitamin D, and hs-CRP, which remained relatively constant throughout the age range. Age-specific RIs for 7 routine biochemical markers were determined to address critical gaps in RIs in early life to help improve clinical interpretation of blood test results in young children, including neonates. Established age partitions demonstrate the biochemical changes that take place during child growth and development. These novel data will ultimately better disease management in the Iranian paediatric population and can be of value to clinical and hospital laboratories with similar populations.     

Genome-scale metabolic model-based engineering of Escherichia coli enhances recombinant single-chain antibody fragment production

Biotechnology Letters - Escherichia coli is an attractive and cost-effective cell factory for producing recombinant proteins such as single-chain variable fragments (scFvs). AntiEpEX-scFv is a...     

Detection of Anti-tetanus Toxoid Monoclonal Antibody by Using Modified Polycarbonate Surface

In recent years, CD surface modification methods are employed for immunoassay techniques that is called BioCD technology. In this research, first polycarbonate surface was activated with UV ozone and a hydrophilic surface was obtained. Contact angle measurements and atomic force microscopy technique confirmed the hydrophilic property of surface. After that, tetanus toxoid was immobilized on modified CD surface then specific monoclonal antibody, gold nanoparticles conjugated antibody, silver salt, and hydroquinone were added on modified CD surface. So a sandwiches complex as tetanus toxoid, tetanus toxoid monoclonal antibody, and gold nanoparticles conjugated antibody was obtained on CD surface. ATR result showed the immobilization of tetanus toxoid on modified CD surface. Localized surface plasmon resonance (LSPR) and DLS results confirmed the complex formation. Silver salt and hydroquinone were added for signal amplification. Detection limit of anti-tetanus toxoid IgG monoclonal antibody was obtained 0.005 IU/ml by LSPR and DLS techniques. The presented method increases the assay’s sensitivity. BioCD-based immunoassay for detection of anti-tetanus toxoid IgG monoclonal antibody could be applicable in development and fabrication of biomedical devices.