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Despite extensive research efforts focusing on tackling membrane biofouling, one of the biggest problems associated with membrane technology, there has been little headway in this area. This study presents novel polyethersulfone (PES) membranes synthesized via a phase inversion method at incremental loadings of functionalized oxidized multiwalled carbon nanotubes (OMWCNT) along with 1 wt. % arabic gum (AG). The synthesized OMWCNT were examined using scanning electron microscopy and transmission electron microscopy for morphological changes compared to the commercially obtained carbon nanotubes. Additionally energy-dispersive X-ray spectroscopy was carried out on the raw and OMWCNT materials, indicating an almost 2-fold increase in oxygen content in the latter sample. The cast PES/OMWCNT membranes were extensively characterized, and underwent a series of performance testing using bovine serum albumin solution for fouling tests and model Gram-positive (Bacillus subtilis) and Gram-negative (Escherichia coli) bacterial species for anti-biofouling experiments. Results indicated that the composite PES membranes, which incorporated the OMWCNT and AG, possessed significantly stronger hydrophilicity and negative surface charge as evidenced by water contact angle and zeta potential data, respectively, when compared to plain PES membranes. Furthermore atomic force microscopy analysis showed that the PES/OMWCNT membranes exhibited significantly lower surface roughness values. Together, these membrane surface features were held responsible for the anti-adhesive nature of the hybrid membranes seen during biofouling tests. Importantly, the prepared membranes were able to inhibit bacterial colonization upon incubation with both Gram-positive and Gram-negative bacterial suspensions. The PES/OMWCNT membranes also presented more resilient normalized flux values when compared to neat PES and commercial membrane samples during filtration of both bacterial suspensions and real treated sewage effluents. Taken together, the results of this study allude to OMWCNT and AG as promising additives, for incorporation into polymeric membranes to enhance biofouling resistance.

Polysulfone (PS) membranes blended with different loadings of arabic gum (AG) were synthesized using phase inversion method and the antibacterial properties of the synthesized membranes were tested using a number Gram-negative (Escherichia coli, Klebsiella pneumonia and Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus) bacterial species. It was shown that AG addition to the dope polymer solutions essentially changed porous structure, hydrophilicity and zeta potential of the cast PS/AG membranes. These changes were due to the amphiphilic properties of AG macromolecules that contained negatively charged hydrophilic residues. A pronounced decrease in bacterial attachment was seen in the field emission scanning electron microscopy (FESEM) images for PS/AG membrane samples compared to both commercial (Microdyn-Nadir) and bare PS (without AG) membranes. AG loading dependent trend was observed where the prevention of bacterial colonization on the membrane surface was strongest at the highest (7 wt. %) AG loading in the casting solution. Possible mechanisms for the prevention of bacterial colonization were discussed. Significantly, the inhibition of bacterial attachment and growth on PS/AG membranes was observed for both Gram-positive and Gram-negative bacterial models, rendering these novel membranes with strong biofouling resistance attractive for water treatment applications.

Membrane biofouling has proved to be a major obstacle when it comes to membrane efficiency in membrane-based water treatment. Solutions to this problem remain elusive. This study presents novel polyethersulfone (PES) membranes that are fabricated using the phase inversion method at different loadings of graphene oxide (GO) and 1 wt. % arabic gum (AG) as nanofiller and pore forming agents. Synthesized GO was examined using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) for morphological studies and energy-dispersive X-ray spectroscopy (EDX) for elemental analysis. The prepared GO flakes showed a high content of oxygen-containing groups (~31%). The fabricated membranes were extensively characterized, including water contact angle analysis for hydrophilicity, zeta potential measurements for surface charge, SEM, total porosity and pore size measurements. The prepared membranes underwent fouling tests using bovine serum albumin (BSA) solutions and biofouling tests using model Gram-positive (Bacillus subtilis) and Gram-negative (Escherichia coli) bacterial suspensions as well as real treated sewage effluent (TSE). The results showed that the novel PES/GO membranes possessed strong hydrophilicity and negative surface charge with an increase in porosity, pore size and water flux. The PES/GO membranes exhibited superior antibacterial action against both Gram-positive and Gram-negative bacterial species, implicating PES membranes which incorporate GO and AG as novel membranes that are capable of high antibiofouling properties with high flux.

Engineering antibodies for diagnostic and therapeutic approaches in neurodegenerative diseasesA. Najjar1, N.N. Vaikath2, I, Hmila2, Nour Majbour2, O. El-Agnaf11Life Sciences Division, College of Science and Engineering, Hamad Bin Khalifa University (HBKU), Education City, Qatar Foundation, PO Box 5825, Doha, Qatar2Neurological Disorders Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation, PO Box 5825, Doha, Qatar.Neurodegenerative diseases affect millions of people worldwide, with Parkinson’s disease (PD) ranked as the second most common age-related neurodegenerative disorder affecting over 1 million people in the United States alone. Common neurodegenerative diseases such as PD, Dementia with Lewy Bodies (DLB) and Multiple System Atrophy (MSA) are characterised by progressive deposition of α-synuclein (α-syn) protein within inclusions referred to as Lewy bodies and glial cytoplasmic inclusions respectively. This has led to classifying these diseases under the umbrella term Synucleinopathies due to the pathological accumulation of this protein. The various diseases vary in where the protein is deposited and which regions in the brain become affected.α-Syn is a relatively small protein constituting 140 amino acid residues having an unfolded native state. α-Syn aggregation occurs in a stepwise manner where monomers lead to transient oligomers, which ultimately lead to proto and mature fibrils within neurons. Such accumulation seems to target dopaminergic neurons located in the substantia nigra pars compacta. Current treatment such as Deep Brain Stimulation (DBS) and L-dopa (the precursor for dopamine) does not focus on slowing disease progression; rather it focuses on symptomatic relief.Amongst the various approaches attempting to tackle the pathological features of synucleinopathies, immunotherapy holds much promise. α-Syn antibodies could potentially block processes leading to the pathogenesis of such neurodegenerative diseases. The limitation of such antibodies is their inefficiency in crossing the Blood-Brain Barrier. The aim of our project focuses on using a fusion protein engineered to include the FAB region of an existing antibody, which is confirmation specific to α-syn pathology. This single-chain-fragment-variable is designed to have increased BBB penetration by virtue of its smaller size and its conjugation with a carrier. It is envisaged that with enhanced penetration there will be superior brain targeting results compared to conventional α-syn antibodies. Upon expression and purification of α-syn and various designs of the fusion protein, the two proteins will be extensively characterized by means of Dot Blots, ELISA assays and affinity experiments. Neuronal cell lines and primary neurons from rat or mice will be employed to test our fusion protein in vitro. This will ultimately be done using immunocytochemistry techniques. For in-vivo experiments, the fusion protein will be tested on transgenic mice overexpressing α-syn.The outcomes of this project are threefold. If successful, the fusion protein could be useful in passive immunization of Synucleinopathies, finding its use as a clinical diagnostic tool for such diseases. Further manipulation of the fusion protein, namely attachment of a Fluoro-radiolabelled isotope can be used for imaging using positron emission tomography (PET). This would allow for its use in medical imaging to track α-syn pathology in PD, DLB and MSA patients.