Grafting of Chitosan with Styrene and Maleic Anhydride via Nitroxide‐Mediated Radical Polymerization in Supercritical Carbon Dioxide

A novel synthesis route is used to produce chitosan‐graft‐poly(styrene‐maleic anhydride)‐OH‐TEMPO (CTS‐g‐PSMA‐T). A three‐step reaction scheme is proposed: 1) bromine 4‐OH‐TEMPO oxoammonium salt is synthesized. 2) Hydroxyl‐targeted groups in the CTS molecule are reacted with the synthesized salt in aqueous acid solution. A functionalization of 18.9% is achieved. 3) Graft copolymerization of styrene and maleic anhydride is done via NMRP by a unimolecular initiation system. The reaction is run in a dispersion in supercritical carbon dioxide (scCO₂) in the presence of camphorsulfonic acid (CSA) to avoid autopolymerization. A modified CTS with a graft content of 68% in weight is obtained.

     

The E3-Ligase TRIM Family of Proteins Regulates Signaling Pathways Triggered by Innate Immune Pattern-Recognition Receptors

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Highlights? Nearly half of all 75 TRIM protein family members are innate immune enhancers ? TRIM mRNA expression and protein localization are complexly regulated during infection ? TRIMs confer differential regulation in distinct innate immune signaling pathways     

Evaluation of the humoral immune response and cross reactivity against <Emphasis Type="Italic">Mycobacterium tuberculosis</Emphasis> of mice immunized with liposomes containing glycolipids of <Emphasis Type="Italic">Mycobacterium smegmatis</Emphasis>

Mycobacterium smegmati s (Ms) is a nonpathogenic mycobacteria of rapid growth, which shares many characteristics with Mycobacterium tuberculosis (MTB), the major causative agent of tuberculosis. MTB has several cell wall glycolipids in common with Ms, which play an important role in the pathogenesis of tuberculosis and the induction of a protective immune response against MTB infection in some animal models. In this study, the humoral immune response and cross reactivity against MTB, of liposomes containing a mixture of cell wall glycolipids of Ms and commercial lipids was evaluated, in order to study its possible use as a component of a vaccine candidate against tuberculosis. Liposomes containing total lipids extracted from Ms, distearoyl phosphatidyl choline and cholesterol were prepared by the dehydration-rehydration technique. Balb/c mice were immunized with the liposomes obtained and the antibody response and cross reactivity against MTB were tested by ELISA. Total lipids extract from Ms showed the presence of several polar glycolipids in common with MTB, such as phosphatidylinositol mannosides. Liposomes that contained glycolipids of Ms were capable of inducing a specific IgG antibody response that allowed the recognition of surface antigens of MTB. The results of this study demonstrated the presence of immunogenic glycolipids in Ms, which could be included to enhance the protective effects of subunit vaccine formulations against tuberculosis.     

Evaluation of specific humoral immune response and cross reactivity against <Emphasis Type="Italic">Mycobacterium tuberculosis</Emphasis> antigens induced in mice immunized with liposomes composed of total lipids extracted from <Emphasis Type="Italic">Mycobacterium smegmatis</Emphasis>

The development of a new tuberculosis (TB) vaccine has become one of the main objectives of the scientific community. Protein antigens have been widely explored as subunit TB vaccines, however lipid antigens could be equally important to be used or included in such a vaccine. The aim of this study was to demonstrate the potential of a liposome formulation composed of an extract of lipids from Mycobacterium smegmatis (Ms) as a TB vaccine candidate. We evaluated the immunogenicity of this formulation as well as the cross reactive response against antigens from Mycobacterium tuberculosis (MTb) in BALB/c mice. We determined the anti-liposome IgG response in sera from TB patients and from healthy subjects who displayed a positive (PPD+) or negative (PPD-) tuberculin skin test. A significant increase in anti-liposome IgG (p<0.05) was detected in animals immunized with Bacille Calmette-Guérin (BCG) compared with all groups, and in the group immunized with liposomes from Ms (LMs) compared to animals immunized with either LMs adjuvanted with aluminium (LMs-A) or the negative control group (phosphate buffered saline, PBS) respectively. With respect to the cross reactive response against a cocktail of cell wall antigens (CWA) from MTb, significantly higher IgG levels were observed in animals immunized with BCG and LMs compared to negative controls and either, aluminium-adjuvanted liposomes (LMs-A) or montanide (LMs-M) (p<0.05). Furthermore, the anti-liposome IgG response was significantly superior in sera from pulmonary TB patients compared to PPD+ and PPD- healthy subjects (p<0.001) suggesting the expression of these antigens in vivo during active MTb infection. The results obtained provide some evidence for the potential use of liposomes containing total lipid extracts of Ms as a TB vaccine candidate.     

A proteoliposome formulation derived from <Emphasis Type="Italic">Bordetella pertussis</Emphasis> induces protection in two murine challenge models

Whooping cough remains a health problem despite high vaccination coverage. It has been recommended that development of new strategies provide long-lasting immunity. The aim of this work was to evaluate the potential of proteoliposomes (PL) extracted from Bordetella pertussis as a vaccine candidate against whooping cough. The size of the B. pertussis PL was estimated to be 96.7±50.9 nm by Scanning Correlation Spectroscopy and the polydispersity index was 0.268. Western blots using monoclonal antibodies revealed the presence of pertussis toxin, pertactin, and fimbriae 3. The Limulus Amebocyte Lisate (LAL) assay showed endotoxin levels lower than those reported for whole cell pertussis licensed vaccines, while the Pyrogen Test indicated 75 ng/mL/Kg. The PL showed high protection capacity in mouse challenge models. There was 89.7% survival in the intracerebral challenge and total reduction of the number of CFU in the intranasal challenge. No significant differences (p>0.05) were observed between mice immunized with B. pertussis PL and the Cuban DTwP vaccine, whichever challenge model used. These results encouraged us to continue the development of the B. pertussis PL as a component of a new combined vaccine formulated with tetanus and diphtheria toxoids or as a booster dose for adolescents and adults.     

Root canal filling quality of mandibular molars with EndoSequence BC and AH Plus sealers: A micro‐CT study

The aim of this study was to compare, by micro‐computed tomography (micro‐CT) analysis, the obturation quality of two filling methods: the single‐cone technique with the bioceramic EndoSequence BC sealer and the continuous wave technique with the resin‐based AH Plus sealer. Twenty mandibular molars were divided into two groups (n = 10) according to the sealer used. Only the mesial roots, which are known to have mostly two canals, were used. The specimens were scanned before and after instrumentation and after obturation. Root canal volume after instrumentation and filling volume were calculated to obtain the percentage volumes of filling, voids and gaps. All specimens presented final volumes that were smaller than the initial volumes (P < 0.05). There was no significant difference between groups for filling volume, voids and gaps (P > 0.05). Using two filling methods, EndoSequence BC and AH Plus promoted a similar root filling quality in mesial roots of mandibular molars. Neither sealer was able to fill the root canal system completely.