Analytical Extractables and Leachables from Vat-Printed Photopolymers: Specimen State, Extraction Design, Analytical Coverage and Cross-Study Comparability
Segurola, Juan
2026-09-14 · Report · Version 0.2
Vat photopolymerisation creates chemically and spatially heterogeneous material states through printing, washing, post- curing, sterilisation, coating, ageing and other post-process operations. Extractables and leachables measurements made on these materials are therefore conditional on both the specimen history and the analytical design. Published studies use different extraction media, temperatures, durations, specimen geometries, surface-to-volume ratios, sampling schedules, target lists, analytical platforms and normalization bases. Consequently, a low or high reported release value cannot be interpreted independently of the method that generated it. This review develops a reporting and comparison framework for analytical release from vat-printed photopolymers used in direct or indirect fluid-contact workflows. The evidence base spans dental and orthodontic materials, biopharmaceutical and cell-and-gene-therapy components, SLA moulds used for PDMS replication, organ-on-chip parts and indirect mould-to-PDMS-to-fluid transfer. The framework separates manufacturing purification from analytical extraction; extractables from leachables; direct from indirect transfer; targeted from broader analytical coverage; and chemical characterisation from downstream toxicological evaluation. It treats coating, irradiation, autoclaving, ageing and other treatments as part of specimen identity rather than as generic improvements. A minimum qualification architecture is proposed covering printed-specimen state, extraction design, geometry and accessibility, analytical coverage, method performance, normalization, time-resolved interpretation and toxicological handoff. Quantitative pooling is considered defensible only when these states are matched or explicitly reconciled. Where they are not, qualitative or stratified comparison is more appropriate than numerical ranking. The resulting framework is intended to improve reproducibility and cross-study interpretability without converting heterogeneous study conditions into a universal VPP extraction standard.