{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,9]],"date-time":"2026-09-09T05:09:50Z","timestamp":1788930590610,"version":"build-2803163510"},"reference-count":35,"publisher":"MDPI AG","issue":"17","license":[{"start":{"date-parts":[[2026,9,3]],"date-time":"2026-09-03T00:00:00Z","timestamp":1788393600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Minister of Science","award":["RID\/SP\/0048\/2024\/01"],"award-info":[{"award-number":["RID\/SP\/0048\/2024\/01"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>A central challenge in implantable local-delivery systems is to determine how internal device architecture shapes solute transport before drug-specific loading, release, and biological validation are available. This study examines the reservoir\u2013channel architecture of the previously characterized KTD\/KTM Ti-6Al-4V capsule platform and evaluates its effect on diffusion-dominated concentration redistribution in a preliminary finite-element model. Micro-computed tomography (micro-CT) was used for qualitative characterization of the as-fabricated internal architecture, whereas the representative computational geometry was defined from the capsule computer-aided design (CAD) concept and previously reported dimensions. Transport of a nominal, fully dissolved species was modeled in COMSOL Multiphysics 5.2 using Fickian diffusion with a prescribed effective diffusion coefficient (Deff = 1 \u00d7 10\u22129 m2\/s) and a nominal peak initial concentration scale of 1.0 mol\/m3. Under the closed no-flux condition, the internal control-point concentration decreased to near zero within approximately 4 h, while the remote outer control point reached approximately 0.002\u20130.003 mol\/m3 by 6 h. A one-sided Dirichlet sink produced a more directional concentration field, demonstrating the sensitivity of the simulated distribution to geometry and boundary conditions. These results describe an idealized, CAD-informed diffusion problem and do not represent experimentally validated drug-release kinetics, therapeutic concentrations, or biological performance. The model is therefore intended as a design-phase framework for guiding subsequent drug-specific transport and experimental validation studies.<\/jats:p>","DOI":"10.3390\/ma19173758","type":"journal-article","created":{"date-parts":[[2026,9,3]],"date-time":"2026-09-03T16:21:21Z","timestamp":1788452481000},"page":"3758","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Internal Architecture of a 3D-Printed Ti-6Al-4V Capsule and Preliminary FEM Simulation of Diffusion: CAD-Informed Modeling with Qualitative Micro-CT Characterization"],"prefix":"10.3390","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7098-9622","authenticated-orcid":false,"given":"Katarzyna","family":"Kazimierska","sequence":"first","affiliation":[{"name":"Faculty of Mechatronics, Kazimierz Wielki University, Miko\u0142aja Kopernika 1, 85-074 Bydgoszcz, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5398-2405","authenticated-orcid":false,"given":"Grzegorz","family":"Szala","sequence":"additional","affiliation":[{"name":"Faculty of Mechatronics, Kazimierz Wielki University, Miko\u0142aja Kopernika 1, 85-074 Bydgoszcz, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2886-0040","authenticated-orcid":false,"given":"Adam","family":"Mazurkiewicz","sequence":"additional","affiliation":[{"name":"Faculty of Mechanical Engineering, Bydgoszcz University of Science and Technology, Al. Prof. S. Kaliskiego 7, 85-796 Bydgoszcz, Poland"},{"name":"Department of Mechanics, University of C\u00f3rdoba, Cta. Madrid-C\u00e1diz, Km. 396, 14071 C\u00f3rdoba, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0009-3506-2125","authenticated-orcid":false,"given":"Miko\u0142aj","family":"Wi\u015bniewski","sequence":"additional","affiliation":[{"name":"Alufasady LCC, Nakielska 247, 85-391 Bydgoszcz, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0005-6362-419X","authenticated-orcid":false,"given":"Igor","family":"Olszewski","sequence":"additional","affiliation":[{"name":"Faculty of Mechatronics, Kazimierz Wielki University, Miko\u0142aja Kopernika 1, 85-074 Bydgoszcz, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,3]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1016\/j.jconrel.2011.11.031","article-title":"Local drug delivery strategies for cancer treatment: Gels, nanoparticles, polymeric films, rods, and wafers","volume":"159","author":"Wolinsky","year":"2012","journal-title":"J. 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