Ingestion of botulinum neurotoxin (BoNT) results in botulism, a severe and frequent fatal disease known in the world. Current treatments rely on antitoxins, such as equine antitoxin and human botulism immunoglobulin. In some cases, side effects have been reported, including early anaphylactic shock and late serum sickness. Thus, diagnosis and treatment measure of BoNT are necessary and crucial. In the present study, a single-domain variable heavy-chain (VHH) antibody fragment was obtained from an immune dromedary phage display library against the putative binding domain of botulinum neurotoxin E (BoNT/E), a non-toxic 50-kDa fragment. The characteristics of nanobody VHH include excellent production, superior heat stability and specific binding capacity to soluble antigen without cross-reaction to other relevant or irrelevant antigens. A total of 150 ng/Kg of nanobody entirely neutralized 3LD50 of the BoNT/E in an in vivo challenge of the mice. This phenomenon indicates BoNT/E toxin neutralizing capacity of the produced nanobody. These results also suggest possession of unique properties by the nanobody applicable in diagnostics or therapeutic purposes.

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Vibrio cholerae is considered one of the major health threats in developing countries. Lack of efficient vaccine, short incubating time of the disease, and bacterium ability to survive in aquatic environment have made cholera one of the most epidemic diseases yet known. The lipopolysaccharide is one of the bacterium key antigens used to classify V. cholerae into 206 serogroups. V. cholerae serogroup O1 is a causative agent of all cholera pandemics. Research has shown that anti-lipopolysaccharide (LPS) antibodies could provide protective immunity in cholera cases. In this research, we used N-terminal fragments of the camel's heavy-chain antibodies called VHH or nanobodies and produced a phagemid library. The obtained library was panned against V. cholerae O1 LPS, and four monoclonal nanobodies were isolated. Isolated nanobodies were tested in LPS ELISA and bacterial ELISA. The nanobody with the highest affinity toward the bacterium was used in an in vivo challenge and successfully neutralized the bacterium infection. The isolated nanobody showed high thermostability and proteolytic resistance in characterization tests.

Selenium (Se) is an important microelement with numerous positive effects on human health and diseases. It is important to specify that the status and consumption of Se are for a specific community as the levels of Se are extremely unpredictable between different populations and regions. Our existing paper was based on the impacts of Se on human health and disease along with data on the Se levels in Middle Eastern countries. Overall, the findings of this comprehensive review show that the consumption and levels of Se are inadequate in Middle Eastern nations. Such findings, together with the growing awareness of the importance of Se to general health, require further work primarily on creating an acceptable range of blood Se concentration or other measures to determine optimal Se consumption and, consequently, to guarantee adequate Se supplementation in populations at high risk of low Se intake.

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The isolated UreC nanobody can specifically detect and bind to UreC and inhibit urease activity. This nanobody could be a novel class of treatment measure against H. pylori infection.

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Prostate cancer is the most common type of cancer in men. The antibody-mediated therapy for cancer treatment depends on the identification of selected molecular targets. The prostate-specific membrane antigen (PSMA) is a potential molecular target in prostate cancer and is abundantly expressed in this type of cancer. This study is aimed at designing and producing a recombinant PSMA epitope and a monoclonal nanobody with a high affinity toward the PSMA protein. A DNA fragment encoding the dominant epitopes of PSMA was designed, synthesized, and expressed in E. coli BL21 (DE3). A camel was immunized with the purified recombinant PSMA (rPSMA). Following mRNA isolation and cDNA synthesis, the variable fragment of heavy-chain antibodies (VHH) fragments were cloned and displayed on the surface of an M13 phage and used in sequential panning rounds. After phage ELISA and selection of colonies with the highest affinity, soluble nanobodies were produced and evaluated. Affinity of the nanobodies to rPSMA was estimated to be 3.5 × 10-7. Adherence of the purified anti-PSMA VHH was tested in cell-ELISA in the LnCaP and PC3 cell lines. VHH efficiently bound to LnCaP cells. The high specificity and affinity of this nanobody suggests its possible application as an effective tool in the diagnosis and treatment of prostate cancer.