Passerini chemistries for synthesis of polymer pro-drug and polymersome drug delivery nanoparticles

New materials chemistries are urgently needed to overcome the limitations of existing biomedical materials in terms of preparation, functionality and versatility, and also in regards to their compatibility with biological environments. Here, we show that Passerini reactions are especially suited for the preparation of drug delivery materials, as with relatively few steps, polymers can be synthesized with functionality installed enabling drug conjugation and encapsulation, self-assembly into micellar or vesicular architectures, and with facile attachment triggerable chemistries. The polymers can be made with a variety of building blocks and assemble into nanoparticles, which are rapidly internalized in triple negative breast cancer (TNBC) cells. In addition, the polymers transport drug molecules efficiently through 3D cell cultures, and when designed with chemistries allowing pH-mediated release, exhibit greater efficacy against TNBC cells compared to the parent drug

Sacrificial Adhesive Bonding: A Powerful Method For Fabrication Of Glass Microchips.

A new protocol for fabrication of glass microchips is addressed in this research paper. Initially, the method involves the use of an uncured SU-8 intermediate to seal two glass slides irreversibly as in conventional adhesive bonding-based approaches. Subsequently, an additional step removes the adhesive layer from the channels. This step relies on a selective development to remove the SU-8 only inside the microchannel, generating glass-like surface properties as demonstrated by specific tests. Named sacrificial adhesive layer (SAB), the protocol meets the requirements of an ideal microfabrication technique such as throughput, relatively low cost, feasibility for ultra large-scale integration (ULSI), and high adhesion strength, supporting pressures on the order of 5 MPa. Furthermore, SAB eliminates the use of high temperature, pressure, or potential, enabling the deposition of thin films for electrical or electrochemical experiments. Finally, the SAB protocol is an improvement on SU-8-based bondings described in the literature. Aspects such as substrate/resist adherence, formation of bubbles, and thermal stress were effectively solved by using simple and inexpensive alternatives.51327

Synthesis of Passerini-3CR Polymers and Assembly into Cytocompatible Polymersomes

© 2020 The Authors. Published by Wiley-VCH GmbH The versatility of the Passerini three component reaction (Passerini-3CR) is herein exploited for the synthesis of an amphiphilic diblock copolymer, which self-assembles into polymersomes. Carboxy-functionalized poly(ethylene glycol) methyl ether is reacted with AB-type bifunctional monomers and tert-butyl isocyanide in a single process via Passerini-3CR. The resultant diblock copolymer (P1) is obtained in good yield and molar mass dispersity and is well tolerated in model cell lines. The Passerini-3CR versatility and reproducibility are shown by the synthesis of P2, P3, and P4 copolymers. The ability of the Passerini P1 polymersomes to incorporate hydrophilic molecules is verified by loading doxorubicin hydrochloride in P1DOX polymersomes. The flexibility of the synthesis is further demonstrated by simple post-functionalization with a dye, Cyanine-5 (Cy5). The obtained P1-Cy5 polymersomes rapidly internalize in 2D cell monolayers and penetrate deep into 3D spheroids of MDA-MB-231 triple-negative breast cancer cells. P1-Cy5 polymersomes injected systemically in healthy mice are well tolerated and no visible adverse effects are seen under the conditions tested. These data demonstrate that new, biodegradable, biocompatible polymersomes having properties suitable for future use in drug delivery can be easily synthesized by the Passerini-3CR

Bradykinin B2 Receptors of Dendritic Cells, Acting as Sensors of Kinins Proteolytically Released by Trypanosoma cruzi, Are Critical for the Development of Protective Type-1 Responses

Although the concept that dendritic cells (DCs) recognize pathogens through the engagement of Toll-like receptors is widely accepted, we recently suggested that immature DCs might sense kinin-releasing strains of Trypanosoma cruzi through the triggering of G-protein-coupled bradykinin B2 receptors (B2R). Here we report that C57BL/6.B2R−/− mice infected intraperitoneally with T. cruzi display higher parasitemia and mortality rates as compared to B2R+/+ mice. qRT-PCR revealed a 5-fold increase in T. cruzi DNA (14 d post-infection [p.i.]) in B2R−/− heart, while spleen parasitism was negligible in both mice strains. Analysis of recall responses (14 d p.i.) showed high and comparable frequencies of IFN-γ-producing CD4+ and CD8+ T cells in the spleen of B2R−/− and wild-type mice. However, production of IFN-γ by effector T cells isolated from B2R−/− heart was significantly reduced as compared with wild-type mice. As the infection continued, wild-type mice presented IFN-γ-producing (CD4+CD44+ and CD8+CD44+) T cells both in the spleen and heart while B2R−/− mice showed negligible frequencies of such activated T cells. Furthermore, the collapse of type-1 immune responses in B2R−/− mice was linked to upregulated secretion of IL-17 and TNF-α by antigen-responsive CD4+ T cells. In vitro analysis of tissue culture trypomastigote interaction with splenic CD11c+ DCs indicated that DC maturation (IL-12, CD40, and CD86) is controlled by the kinin/B2R pathway. Further, systemic injection of trypomastigotes induced IL-12 production by CD11c+ DCs isolated from B2R+/+ spleen, but not by DCs from B2R−/− mice. Notably, adoptive transfer of B2R+/+ CD11c+ DCs (intravenously) into B2R−/− mice rendered them resistant to acute challenge, rescued development of type-1 immunity, and repressed TH17 responses. Collectively, our results demonstrate that activation of B2R, a DC sensor of endogenous maturation signals, is critically required for development of acquired resistance to T. cruzi infection

Passerini chemistries for synthesis of polymer pro-drug and polymersome drug delivery nanoparticles

New materials chemistries are urgently needed to overcome the limitations of existing biomedical materials in terms of preparation, functionality and versatility, and also in regards to their compatibility with biological environments. Here, we show that Passerini reactions are especially suited for the preparation of drug delivery materials, as with relatively few steps, polymers can be synthesized with functionality installed enabling drug conjugation and encapsulation, self-assembly into micellar or vesicular architectures, and with facile attachment triggerable chemistries. The polymers can be made with a variety of building blocks and assemble into nanoparticles, which are rapidly internalized in triple negative breast cancer (TNBC) cells. In addition, the polymers transport drug molecules efficiently through 3D cell cultures, and when designed with chemistries allowing pH-mediated release, exhibit greater efficacy against TNBC cells compared to the parent drug

Effects of Zinc Source and Level in Low ABC-4 Diets on Nursery Pig Growth Performance and Fecal Characteristics

A total of 360 weanling barrows (DNA 200 × 400; initially 13.0 ± 0.07 lb) were used in a 38-d study to evaluate the effects of diets containing different levels of a novel Zn source (HiZox, Animine Precision Minerals, Annecy, France) and different levels of crude protein (CP) in low acid-binding capacity at pH 4 (ABC-4) diets on growth performance and fecal characteristics. Pigs were randomly assigned to pens (5 pigs per pen) and pens were assigned to 1 of 6 treatments with 12 pens per treatment. Diets were fed in 3 phases: phase 1 from d 0 to 10, phase 2 from d 11 to 24, and phase 3 from d 25 to 38. All diets were formulated to have low ABC-4. Treatment 1, the negative control (NC), was formulated to contain 150 ppm of Zn (HiZox) throughout the experiment (d 0 to 38). Treatment 2, the positive control (PC), was formulated to contain 3,000 ppm (phase 1) and 2,000 ppm (phase 2) of Zn (ZnO). Treatment 3 (low HiZox) contained 500 ppm (phase 1) and 300 ppm (phase 2) of Zn. Treatment 4 (low HiZox + low CP) was formulated similar to treatment 3 but contained lower CP (19.3% CP) than the NC, PC, low, and high HiZox treatments (21.3% CP). Treatment 5 (high HiZox) contained 800 ppm (phase 1) and 500 ppm (phase 2) of Zn. Treatment 6 (high HiZox + low CP) was formulated to be similar to treatment 5 but contained less CP (19.3% CP). In phase 3, all pigs were fed a common diet containing 150 ppm of Zn (HiZox) and 21.3% CP. For the experimental period (d 0 to 24), pigs fed high HiZox + low CP had poorer F/G (P \u3c 0.05) than NC, PC, low HiZox, and high HiZox. In addition, ADG (quadratic, P = 0.007) and ADFI (quadratic, P = 0.018) increased as HiZox increased, and pigs fed diets with low CP were less feed efficient (P = 0.043) than those fed the same levels of HiZox but with high CP. Overall, pigs fed low CP diets had poorer F/G (P = 0.041) than pigs fed similar levels of HiZox with high CP. For fecal characteristics, pigs fed low CP had higher (P = 0.008) dry matter (DM) and an interaction between day and CP (P = 0.040) was detected for fecal scores with low CP diets improving stool consistency to a greater extent on d 10 than on d 23. In summary, increasing levels of HiZox improved performance of nursery pigs during phases 1 and 2, and pigs fed a regimen of 800 and 500 ppm of HiZox in the first 2 phases in low ABC-4 diets had similar performance to pigs fed pharmacological levels of Zn from ZnO in the overall period. Finally, pigs fed low CP diets had improved fecal characteristics, but poorer F/G throughout the nursery period

BRCA2 polymorphic stop codon K3326X and the risk of breast, prostate, and ovarian cancers

Background: The K3326X variant in BRCA2 (BRCA2*c.9976A>T; p.Lys3326*; rs11571833) has been found to be associated with small increased risks of breast cancer. However, it is not clear to what extent linkage disequilibrium with fully pathogenic mutations might account for this association. There is scant information about the effect of K3326X in other hormone-related cancers. Methods: Using weighted logistic regression, we analyzed data from the large iCOGS study including 76 637 cancer case patients and 83 796 control patients to estimate odds ratios (ORw) and 95% confidence intervals (CIs) for K3326X variant carriers in relation to breast, ovarian, and prostate cancer risks, with weights defined as probability of not having a pathogenic BRCA2 variant. Using Cox proportional hazards modeling, we also examined the associations of K3326X with breast and ovarian cancer risks among 7183 BRCA1 variant carriers. All statistical tests were two-sided. Results: The K3326X variant was associated with breast (ORw = 1.28, 95% CI = 1.17 to 1.40, P = 5.9x10- 6) and invasive ovarian cancer (ORw = 1.26, 95% CI = 1.10 to 1.43, P = 3.8x10-3). These associations were stronger for serous ovarian cancer and for estrogen receptor–negative breast cancer (ORw = 1.46, 95% CI = 1.2 to 1.70, P = 3.4x10-5 and ORw = 1.50, 95% CI = 1.28 to 1.76, P = 4.1x10-5, respectively). For BRCA1 mutation carriers, there was a statistically significant inverse association of the K3326X variant with risk of ovarian cancer (HR = 0.43, 95% CI = 0.22 to 0.84, P = .013) but no association with breast cancer. No association with prostate cancer was observed. Conclusions: Our study provides evidence that the K3326X variant is associated with risk of developing breast and ovarian cancers independent of other pathogenic variants in BRCA2. Further studies are needed to determine the biological mechanism of action responsible for these associations

Temas de investigação em direitos humanos para o século XXI

Edição comemorativa do 10.º aniversário do Mestrado em Direitos Humanos da Universidade do Minho.Este livro é uma celebração do ensino e da investigação em direitos humanos que têm vindo a ser desenvolvidos, na Escola de Direito da Universidade do Minho, há já mais de uma década. A sua publicação num momento em que se avolumam os riscos para valores fundamentais subjacentes à proteção dos direitos humanos – como a igualdade e a não discriminação, a proibição da escravatura e de tratamentos cruéis, desumanos e degradantes, a liberdade de religião ou crença, entre muitos outros –, torna-o especialmente oportuno. Os sinais de aparente retrocesso no consenso das nossas sociedades a respeito desses valores – visíveis no triunfo político de discursos abertamente racistas, xenófobos, sexistas, etc. – recordam-nos que, também no mundo ocidental, os direitos humanos são um work in progress, não um dado adquirido. Os novos riscos para a dignidade da pessoa humana associados aos avanços tecnológicos andam de par com velhas formas de subalternização e de opressão. O campo para a reflexão crítica é muito vasto. Os temas que hoje (pre)ocupam académicos, decisores políticos e ativistas de direitos humanos são também aqueles que estruturam o plano de estudos do Mestrado em Direitos Humanos da Universidade do Minho. Todos estes temas surgem ao longo do presente livro, que reúne contributos de muitos dos membros da comunidade científica e académica que o Mestrado em Direitos Humanos mobilizou e ajudou a dinamizar ao longo da última década, entre docentes do Mestrado, colaboradores em júris de provas públicas e/ou na orientação de mestrandos, oradores convidados e estudantes. Os textos aqui reunidos refletem bem as sinergias interdisciplinares, interinstitucionais e inter-nacionais que o Mestrado em Direitos Humanos foi capaz de criar, não apenas pela variedade de campos disciplinares representados – Direito, Filosofia, Relações Internacionais, Antropologia –, mas também pela participação de autores que são docentes e/ou investigadores em diversas instituições nacionais e estrangeiras, como a Faculdade de Direito da Universidade do Porto, a Faculdade de Economia da Universidade de Coimbra, a Universidade Federal da Paraíba e a Pontifícia Universidade Católica de São Paulo.info:eu-repo/semantics/publishedVersio