a b s t r a c tDiblock copolymers of 4-vinylpyridine (4VP) and oligoethyleneglycol methyl ether methacrylate (OEGMA) were synthesized for the first time using RAFT polymerization technique as potential drug delivery systems. Effects of the number of ethylene glycol units in OEGMA, chain length of hydrophobic P4VP block, pH, concentration and temperature on the solution behavior of the copolymers were investigated comprehensively. Copolymer chains formed micelles at pH values higher than 5 whereas unimeric polymers were observed to exist below pH 5, owing to the repulsion between positively charged P4VP blocks. The size of the micelles was dependent on the relative length of blocks, P4VP and POEGMA. Thermo-responsive properties of copolymers were investigated depending on the pH and length of P4VP block. The increase in the length of P4VP block decreased the LCST substantially at pH 7. At pH 3, LCST of copolymers shifted to higher temperatures due to the increased interaction of copolymers with water through positively charged P4VP block.

IntroductionCoronaviruses belonging to the family Coronaviridae from the members of the order Nidovirales are spherical, enveloped, and single-stranded positive RNA viruses within the diameter range of 60-220 nm, which have rodshaped glycoprotein extensions in their outer surfaces and carry a genome size of 26-32 kb (King et al., 2011;Shereen et al., 2020). Among the coronaviruses, which are classified into four subgroups: alpha (α), beta (β), gamma (γ), and delta (δ) (Kin et al., 2015), the strains that currently infect humans are seven; HCoV229E, HCoV-OC43, SARS-CoV, HCoV-NL63, HCoV-HKU1, MERS-CoV, and SARS-CoV-2 (severe acute respiratory syndrome coronavirus) (Nomura et al., 2004).Following the severe acute respiratory syndrome (SARS-CoV) that occurred in China in 2002, MERS-CoV caused endemic in the Middle East countries in 2013 (Brian and Baric, 2005), while SARS-CoV-2 created pandemics in 2020 1 . The SARS-1 WHO has declared COVID-19 as a pandemic. [online] Website: https://www.who.int/dg/speeches/detail/who-director-general-s-opening-remarks-at-the-media-briefing-on-covid-19---11-march-2020 [accessed date 25.05.2020]CoV-2, which caused the COVID-19 pandemic, belongs to the group of betacoronavirus and its clinical manifestations are evaluated in three different stages: i) mild; weakness, fever, dry cough, fatigue, and upper respiratory tract infections, ii) moderate; shortness of breath, severe cough, diarrhea, iii) severe; severe pneumonia, acute lung injury (ALI), and acute respiratory distress syndrome (ARDS), sepsis and septic shock (Cascella et al., 2020). Currently, there is no specific antiviral therapy developed against SARS-CoV-2.Based on previous experiences in SARS-CoV and MERS-CoV outbreaks, some treatment strategies have been developed (Cascella et al., 2020;Mehta et al., 2020;. These strategies include antiviral treatments or combinations of these that have been known to be safe for humans and used in previous viral outbreaks,

Research on the conjugates of synthetic polyelectrolytes with antigenic molecules, such as proteins, peptides, or carbohydrates, is an attractive area due to their highly immunogenic character in comparison to classical adjuvants. For example, polyacrylic acid (PAA) is a weak polyelectrolyte and has been used in several biomedical applications such as immunological studies, drug delivery, and enzyme immobilization. However, to our knowledge, there are no studies that document immune-stimulant properties of PAA in Leishmania infection. Therefore, we aimed to develop a potential vaccine candidate against leishmaniasis by covalently conjugating PAA with an immunologically vital molecule of lipophosphoglycan (LPG) found in Leishmania parasites. In the study, LPG and PAA were conjugated by a multi-step procedure, and final products were analyzed with GPC and MALDI-TOF MS techniques. In cytotoxicity experiments, LPG-PAA conjugates did not indicate toxic effects on L929 and J774 murine macrophage cells. We assume that LPG-PAA conjugate can be a potential vaccine candidate, and will be immunologically characterized in further studies to prove its potential.

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Poly L-lactic acid grafted starch (St-g-PLA) copolymers were directly synthesized under microwave irradiation by using sodium hydroxide (NaOH) and stannous 2-ethyl hexanoate acting as a catalyst, without the use of toxic solvents. The product were characterized by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance ( 13 C CP/MAS NMR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA-DTG). SEM analysis indicated that microwave heating had a considerable effect on the interfacial adhesion between PLA and starch. Thermogravimetric analysis (TGA-DTG) revealed that copolymers exhibited better thermal stability. Maximum PLA grafting was achieved with the following reaction conditions: 450W microwave power, monomer ratio of 1:5 and 0.4M of NaOH. This study demonstrates that it is possible to obtain St-g-PLA copolymers with better processing characteristics and smaller sizes via microwave-assisted synthesis. The applied procedure is an interesting "green" synthesis method for the production of biodegradable materials used in a diverse range of applications. V C 2015Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42937.