Carbon nanostructures: a comprehensive review of potential applications and toxic effects.

There is no doubt that nanotechnology has revolutionized our life since the 1970s when it was first introduced. Nanomaterials have helped us to improve the current products and services we use. Among the different types of nanomaterials, the application of carbon-based nanomaterials in every aspect of our lives has rapidly grown over recent decades. This review discusses recent advances of those applications in distinct categories, including medical, industrial, and environmental applications. The first main section introduces nanomaterials, especially carbon-based nanomaterials. In the first section, we discussed medical applications, including medical biosensors, drug and gene delivery, cell and tissue labeling and imaging, tissue engineering, and the fight against bacterial and fungal infections. The next section discusses industrial applications, including agriculture, plastic, electronic, energy, and food industries. In addition, the environmental applications, including detection of air and water pollutions and removal of environmental pollutants, were vastly reviewed in the last section. In the conclusion section, we discussed challenges and future perspectives.

Serum DKK1 is correlated with γ peak of serum electrophoresis in multiple myeloma: a multicenter biomarker study.

Aim: DKK1 is reported to be produced at high levels by myeloma cells. Therefore, the applicability of DKK1 as a tumor marker for multiple myeloma (MM) diagnosis was examined. Methods: Serum samples were collected and analyzed by DKK1 concentration kit and capillary zone electrophoresis. Then, the obtained results were statically analyzed. Results: It has been determined that the 10 ng/ml of DKK1 is the optimal level for MM diagnosis. Moreover, there was an ascending linear correlation between the DKK1 concentration and γ peak. Discussion: The observed correlation could be rooted in the positive feedback loop between MM cells and the mesenchymal stem cells. In view of these results, DKK1 could be deemed as diagnostic marker for MM.

In Silico Structural Prediction and Production of a Chimeric Recombinant Dickkopf-1 (DKK-1) Antigen.

Dickkopf (DKK) family of proteins are known as antagonists for the Wnt-ß-catenin signaling pathway. It is suggested that the Dickkopf-1 (DKK-1) has a role in several diseases such as hepatocellular carcinomas, hepatoblastomas, Wilms' tumors, lung cancer and Myeloma bone disease. The aim of the present study was to produce a chimeric-recombinant DKK-1 protein in order to induce immune response against the antigen. The recombinant Dickkopf-1 (rDKK-1) protein was designed using bioinformatics analysis. The standard methods were used for cloning, expression and purification. The structure of recombinant protein was analyzed by spectroscopy methods. Enzyme-linked immunosorbent assay (ELISA) and Western blotting were performed to confirm the recombinant protein using a commercial anti-DKK-1 (whole protein) polyclonal antibody. The immunogenicity of the recombinant DKK-1 was assessed by immunizing, intraperitoneally, BALB/C mice four times with the 31-kDa and 45-kDa purified rDKK-1 cloned in pET28a and pET32a vectors respectively. The antibody titer was measured in due course of time. Stronger immunogenic parts of the protein were selected based on in-silico predictions and recombinant protein was successfully designed. The chimeric gene was sub-cloned, expressed, purified and refolded. The purified protein was confirmed by Western blotting and ELISA. The three dimensional structural was confirmed by CD spectrum and predicted structures by bioinformatics tools, revealed the stability of helix structures. rDKK-1 protein was capable of inducing immune response with high titer antibody and  excessive humoral immune response. No significant difference was observed between immunization by 31-kDa and 45-kDa antigen.

Production and Characterization of Monoclonal and Polyclonal Antibodies Against Truncated Recombinant Dickkopf-1 as a Candidate Biomarker.

Several studies have reported an increased serum level of Dickkopf (DKK-1) protein in a variety of cancers, including multiple myeloma, lung, colorectal, bone loss, and Alzheimer's disease. This protein has potential to be used as a biomarker for the diagnosis of some cancers, especially bone loss in multiple myeloma. In the present study, to measure the concentration level of DKK-1 protein, rabbit polyclonal antibody (pAb) and mouse monoclonal antibodies (mAbs) were produced against this protein. New Zealand white rabbits and BALB/c mice were immunized with the chimeric recombinant DKK-1 antigen. Immunized mouse spleen cells were fused with SP2/0 cells to generate anti-rDKK-1 antibody-producing hybridoma cells. Antibodies were purified by protein A affinity chromatography and assessed using sodium dodecyl sulfate polyacrylamide gel, western blotting and enzyme-linked immunosorbent assay. These results implied that the pAb and mAb were produced against the DKK-1 protein. The Kd value of 5 × 10-9 M was recorded for the mAb MR6F3 toward native DKK-1, and the Ig isotype was identified as IgG2b. No cross-reactivity was shown with DKK-2 by MR6F3. Collectively, our results revealed that the produced pAb and mAb could be used in the measurement of DKK-1 protein.

A Novel Molecular Design for a Hybrid Phage-DNA Construct Against DKK1.

Nucleic acid immunization has recently exhibited a great promise for immunotherapy of various diseases. However, it is now clear that powerful strategies are imminently needed to improve their efficiency. In this regard, whole bacteriophage particles have been described as efficient DNA vaccine delivery vehicles, capable of circumventing the limitations of naked DNA immunization. Moreover, phage particles could be engineered to display specific peptides on their surfaces. Given these inherent characteristics of phages, we have designed a novel hybrid phage-DNA immunization vector using both M13 and pAAV plasmid elements. Following the construction and in vitro confirmation of the designed vectors, they were used for comparative mice immunization, carrying the same DNA sequence. The results indicated the efficacy of the designed hybrid phage particles, to elicit higher humoral immunity, in comparison to conventional DNA-immunization vectors (pCI). In light of these findings, it could be concluded that using adeno-associated virus (AAV) expression cassette along with displaying TAT peptide on the surface of the phage particle could be deemed as an appealing strategy to enhance the DNA-immunization and vaccination efficacy.

Immunogenicity of a new recombinant IpaC from Shigella dysenteriae type I in guinea pig as a vaccine candidate.

BACKGROUND: Recombinant vaccine technology is one of the most developed means in controlling infectious diseases. However, an effective vaccine against Shigella is still missing. OBJECTIVE: To evaluate recombinant IpaC protein of Shigella as a vaccine candidate. METHODS: In this study we cloned IpaC gene into an expression vector in prokaryotic system. The protein expression was evaluated by SDS-PAGE and Western-Blotting analysis. The recombinant protein was purified using Ni-NTA affinity chromatography. Guinea pigs were immunized with the recombinant protein and the level of immunogenicity was examined by ELISA and Western blotting of IpaC. Challenge test was done through the intraoculary injection of Shigella dysenteriae (6×108 CFU/eye) and after 48 hours was scored for keratoconjunctivitis. RESULTS: The results showed a remarkable level of immunogenicity in terms of antibody response and protection against keratoconjunctivitis in tested animals. The recombinant IpaC protein provided a protective system against Shigella dysenteriae type I during the challenge test. CONCLUSION: The results showed the potential of using recombinant IpaC in preparation of vaccine in perspective studies.

Molecular cloning and biologically active production of IpaD N-terminal region.

Shigella is known as pathogenic intestinal bacteria in high dispersion and pathogenic bacteria due to invasive plasmid antigen (Ipa). So far, a number of Ipa proteins have been studied to introduce a new candidate vaccine. Here, for the first time, we examined whether the N-terminal region of IpaD(72-162) could be a proper candidate for Shigella vaccine. Initially, the DNA sequence coding N-terminal region was isolated by PCR from Shigella dysenteriae type I and cloned into pET-28a expression vector. Then, the heterologous protein was expressed, optimized and purified by affinity Ni-NTA column. Western blot analysis using, His-tag and IpaD(72-162) polyclonal antibodies, confirmed the purity and specificity of the recombinant protein, respectively. Subsequently, the high immunogenicity of the antigen was shown by ELISA. The results of the sereny test in Guinea pigs showed that IpaD(72-162) provides a protective system against Shigella flexneri 5a and S. dysenteriae type I.