ABSTRACT
Antibodies have a wide application in diagnosis and treatment. In order to maintain optimal stability of various functional parts of antibodies such as antigen binding sites, several approaches have been suggested. Using additives such as polysaccharides and polyols is one of the main methods in protecting antibodies against aggregation or degradation in the formulation. The aim of this study was to evaluate the protective effect of various additives on the specific reactivity of monoclonal antibodies [mAbs] against recombinant HBsAg [rHBsAg] epitopes. To estimate the protective effect of different additives on the stability of antibody against conformational epitopes [S3 antibody] and linear epitopes [S7 and S11 antibodies] of rHBsAg, heat shock at 37[degree]C was performed in liquid and solid phases. Environmental factors were considered to be constant. The specific reactivity of antibodies was evaluated using ELISA method. The data were analyzed using SPSS software by Mann-Whitney nonparametric test with the confidence interval of 95%. Our results showed that 0.25 M sucrose, 0.04 M trehalose and 0.5% BSA had the most protective effect on maintaining the reactivity of mAbs [S3] against conformational epitopes of rHBsAg. Results obtained from S7 and S11 mAbs against linear characteristics showed minor differences. The most efficient protective additives were 0.04 M trehalose and 1 M sucrose. Nowadays, application of appropriate additives is important for increasing the stability of antibodies. It was concluded that sucrose, trehalose and BSA have considerable effects on the specific reactivity of anti rHBsAg mAbs during long storage
ABSTRACT
Colorectal cancer is one of the most commonly diagnosed cancers and cancer- related death worldwide. Identification of new specific biomarkers could be helpful to detection of this malignancy. Altered plasma microRNA expression has been identified in many cancers, including colorectal cancer. The main objective of this study was to identify the circulating microRNAs with the most expression changes in colorectal cancer patients compared with neoplasm free healthy individuals. MicroRNA expression profiling was performed on plasma samples of 37 colorectal cancer patients and 8 normal subjects using microRNA microarray. Quantitative real-time reverse transcription polymerase chain reaction was used to validate the two selected altered microR NAs. Plasma samples from 61 colorectal cancer patients and 24 normal subjects were used in our validation study. In profiling study we found a panel of six plasma microRNAs with significant downregulation. MicroRNA-142-3p and microRNA-26a-5p were selected and validated by polymerase chain reaction. Our results demonstrated that expression levels of plasma microRNA-142-3p and microRNA-26a-5p were significantly downregulated in patients with colorectal cancer when compared to control group. Our findings suggest that downregulation of plasma microRNA-142-3p and microRNA-26a-5p might serve as novel noninvasive biomarkers in the diagnosis of colorectal cancer, although more studies are needed to highlight the theoretical strengths
ABSTRACT
In recent decades, the anticancer effect of curcumin has been proven by several studies. Curcumin affects multiple cell signaling pathways and prevents cell proliferation, invasion, metastasis and angiogenesis. However, the aqueous solubility of curcumin and its bioavailability are very low which restricts its anticancer properties. In this research, we have synthesized a monomethoxy poly [ethylene glycol]-Oleate [mPEGOA] di-block copolymer and used a surface PEGylated poly [amidoamine] [PAMAM] dendrimer to improve bioavailability of curcumin in cancer cells. The critical micelle concentration [CMC] of mPEG-OA, drug loading efficiencies, and cytotoxicity in the human glioblastoma cell line [U87MG] of all the prepared nanodevices were thoroughly investigated. Atomic force microscopy [AFM] and dynamic light scattering [DLS] studies have shown that mPEG-OA have two common nanostructures, micelles and polymerosomes. mPEG-OA micelles had a very low CMC [0.03 g/l]. The IC50 of free curcumin [0.01 methanol solution] was 48 microM, curcumin-loaded mPEG-OA was 24 microM, and curcumin-loaded PAMAM dendrimer was 13 microM. Moreover, the PEGylated PAMAM was non-cytotoxic. The results indicated that by using these nanocarriers, the bioavailability of curcumin significantly increased compared to free curcumin. Overall, this research revealed that these curcumin nanocarriers could be considered as appropriate drug delivery systems for curcumin delivery in cancer cells
ABSTRACT
Hepatitis B virus [HBV] infection is the 10th leading cause of death worldwide. The most important diagnostic and screening marker for HBV infection is Hepatitis B surface antigen [HBsAg], and the most widely used HBsAg screening test is Enzyme-linked Immunosorbent Assay [ELISA]. In this study, an ELISA assay has been developed for detection of HBsAg using two novel monoclonal antibodies [mAb] as capture layer and a polyclonal biotinylated Ab as detector phase. We evaluated the sensitivity, specificity, detection limit, seroconversion time, positive and negative predictive values and reproducibility of our assay with standard panels and different serum samples. The results were compared with a well established commercial kit. Both assays showed similar detection limit values of 0.5 to 0.7 ng/ml and the same seroconversion periods of 42 and 65 days for [ad] and [ay] serotypes of HBsAg, respectively. Sensitivity and specificity of the assay were 98.98% and 99.6%, respectively. The positive and negative predictive values of our assay were also calculated as 99.49% and 99.2%, respectively. Analysis of reproducibility of the present assay demonstrated 3.96% and 5.85% intra-and inter-assay coefficient of variations, respectively, which were less than those obtained by the commercial kit. There was a highly significant correlation between our designed assay and the commercial ELISA kit [p < 0.0001, r = 0.957]. Altogether, our results indicate that the designed assay is comparable to the commercial kit in terms of sensitivity, specificity, positive and negative predictive values and reproducibility and could be employed for diagnosis of HBV infection in blood samples