Submissões Recentes

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    Anionic collagen processed by alkaline hydrolysis

    2026 - MASSIMINO, LIVIA C.; BERTOLO-CAGNOTO, MIRELLA R. V.; TESSARO, LARISSA; MARTINS, VIRGINIA da C. A.; MANIGLIA, BIANCA CHIEREGATO; PLEPIS, ANA MARIA de G.; MATHOR, MONICA B.

    Collagen is the most abundant structural protein in the extracellular matrix, and its biocompatibility can be enhanced by chemical modification into a negatively charged matrix. This study investigates the effect of alkaline hydrolysis time (24, 48, 72, and 96` h) on the rheological behavior and processability of anionic concentrated collagen solutions extracted from bovine tendon. By systematically modulating hydrolysis time, we demonstrate how increasing negative charge density drives a rearrangement of the collagen network, resulting in more elastic and shear-thinning behavior, as evidenced by higher storage moduli, increased zero-shear viscosity, and enhanced creep-recovery response. Among the tested formulations, the 72-h hydrolyzed collagen exhibited the most balanced rheological profile and enabled extrusion-based 3D printing with high fidelity, achieving geometry preservation of 104 ± 4% (star angle), 98 ± 2% (scaffold area), and effective macroporosity of 84%. Longer hydrolysis led to decreased scaffold pore size and increased absorption of phosphate-buffered saline. All materials were non-cytotoxic and supported cell adhesion (58.74—74.89%). Overall, this work highlights how rheological characterization can guide the design and processability of collagen-based bioinks, linking structural and mechanical properties to 3D printing performance and biological outcomes.

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    Highlight selection of radiochemistry and radiopharmacy developments by editorial board

    2026 - KISS, OLIVER C.; PENUELAS, IVAN; REY, ANA; YANG, ZHI; GILLINGS, NIC; PILLAI, AMBI; CAZZOLA, EMILIANO; REILLY, RAYMOND M.; TADDEI, CARLOTTA; LIU, JEFF; VAN DAM, MICHAEL; FURUMOTO, SHOZO; ZHANG, JUNBO; BERNARDES, EMERSON S.; LODI, FILIPPO; DEUTHER-CONRAD, WINNIE; HUANG, YA-YAO; LAGEBO, YOHANNES JORGE; EKOUME, FANY P.; AVILA-RODRIGUEZ, MIGUEL A.; SUMMERS, BEVERLEY; ELREFAEI, AMAL; SALGUEIRO, MARIA; RAMOGIDA, CATARINA F.; SCOTT, PETER J. H.

    Background: The Editorial Board of EJNMMI Radiopharmacy and Chemistry releases a biannual highlight commentary to update the readership on trends in the field of radiopharmaceutical development and application of radiopharmaceuticals. Main body: This selection of highlights provides commentary on 25 different topics selected by each co-authoring Editorial Board member addressing a variety of aspects ranging from novel radiochemistry to first-in-human application of novel radiopharmaceuticals. Conclusion: Trends in radiochemistry and radiopharmacy are highlighted. Hot topics cover the entire scope of EJNMMI Radiopharmacy and Chemistry, demonstrating the progress in the research field in many aspects.

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    On the microstructural control of localized corrosion in non-anodized and TSA-anodized AA7475-T761 aluminium alloy

    2026 - ARAUJO, JOAO V. de S.; MELO, HERCILIO G. de; INTAPHAN, WORAPHAN; MACHADO, IZABEL F.; COSTA, ISOLDA; ZHOU, XIAORONG

    The corrosion behaviour of the AA7475-T761 alloy in non-anodized and tartaric–sulfuric acid (TSA) anodized conditions in a chloride environment is investigated. In the non-anodized alloy, localized corrosion initiated at constituent intermetallic particles (IMPs) and grain boundary precipitates, leading to trenching and intergranular attack. In contrast, in the anodized alloy, corrosion initiated at defects located at the film/alloy interface, originating from the dissolution of IMPs during anodizing. These defective regions acted as preferential pathways for electrolyte ingress, promoting underfilm corrosion and pit growth beneath the oxide. While the anodic film delayed the onset of corrosion, the highly localized nature of the attack in the anodized sample increased the severity of the damage once initiated.

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    Dissertação IPEN-doc 32278

    Mapeamento dos desafios e oportunidades para o registro de radiofármacos estrangeiros no Brasil

    2024 - MASCAGNI, DENISE M de P.

    O presente trabalho tem como objetivo mapear os desafios e oportunidades para o registro de radiofármacos estrangeiros no Brasil, com foco na medicina nuclear, uma especialidade que utiliza radionuclídeos para diagnósticos e tratamentos, especialmente em casos de doenças graves, como câncer e patologias cardíacas. O estudo explora o papel dos radiofármacos, como o tecnécio-99m (99mTc), que são essenciais para procedimentos clínicos de alta complexidade. A pesquisa analisa os principais entraves regulatórios enfrentados no Brasil, especialmente impostos adicionais pela Agência Nacional de Vigilância Sanitária (ANVISA) e pela Comissão Nacional de Energia Nuclear (CNEN), que supervisionam a produção, importação e distribuição desses produtos. O trabalho destaca as resoluções mais relevantes, como a RDC Nº 567 de 2021, que permite a importação de radiofármacos para mitigar a escassez, e outras normativas, como as RDCs 263 de 2019 e 451 de 2020, que estabelecem os requisitos regulatórios para o registro dos radiofármacos. O papel do Instituto de Pesquisas Energéticas e Nucleares (IPEN) também é abordado, com destaque pela sua importância na produção nacional de radiofármacos. No entanto, o Instituto enfrenta sérias dificuldades, que resultaram na interrupção e desabastecimento de produtos essenciais, levando à necessidade de importação de radiofármacos de laboratórios estrangeiros. Da mesma forma, regulamentados pela ANVISA, têm sido uma solução temporária para garantir a continuidade de diagnósticos e tratamentos críticos nos serviços de Medicina Nuclear no Brasil.