Development of 3d-printed moulds for histological standardisation in murine models

Abstract

A patologia experimental é uma disciplina fundamental na investigação biomédica, recorrendo a modelos animais e técnicas histopatológicas para estudar os mecanismos subjacentes a diversas doenças. A patologia toxicológica, uma área associada, avalia os efeitos de substâncias tóxicas em organismos vivos, apoiando decisões regulatórias relativas à segurança de fármacos e produtos químicos. A reprodutibilidade dos resultados nesta área depende de uma documentação rigorosa, da aplicação de protocolos padronizados e da participação de patologistas qualificados. Contudo, a transparência metodológica é frequentemente insuficiente, agravada por interpretações realizadas por profissionais sem formação especializada, o que compromete a consistência dos dados.Standardisation in experimental pathology is essential for ensuring reproducible and reliable histological outcomes. This study aimed to develop three-dimensional printed moulds tailored to the morphology of mice’s head, intestines, and kidneys, to improve tissue orientation and alignment, and enhance the consistency of histological processing. Morphometric analyses were conducted on male BALB/c and female C57BL/6 mice, followed by the design and production of organ- and sex-specific moulds using masked stereolithography with two resin types. The moulds were assessed based on their influence on section quality, tissue alignment, and preservation of architecture. Male BALB/c mice exhibited larger cranial dimensions, longer intestines, and larger kidneys compared to female C57BL/6 mice. Customised moulds improved histological outcomes for the intestines and kidneys, but did not enhance results for nasal cavity samples due to limitations in fit and embedding precision. Standard resin produced more durable moulds than water-washable resin, and adjustments to printing parameters significantly reduced structural defects. These findings support the use of tailored moulds to improve histological standardisation and suggest further refinement and broader application as promising directions for future research.