Towards the personalization of gelatin-based 3D patches: a tunable porous carrier for topical applications.

Cell-free based therapies, for example, the use of the cell secretome, have emerged as a promising alternative to conventional skin therapies using bioactive and, when combined with 3D printing technologies, allow the development of personalized dosage forms. This research work aimed to develop gelatin-based patches with controlled network topology via extrusion 3D printing, loaded with cell culture medium as a model of the secretome, and applicable as vehicles for topical delivery. Inks were optimized through rheological and printing assays, and the incorporation of medium had minor effects in printability. Regarding network topology, grid infills rendered more defined structures than the triangular layout, depicting clearer pores and pore area consistency. Release studies showed that filament spacing and infill pattern influenced the release of rhodamine B (model bioactive) and bovine serum albumin (model protein). Moreover, the grid patches (G-0.7/1/0.7), despite having around a seven-fold higher mean pore area than 0.7-mm triangular ones (T-0.7), showed a similar release profile, which can be linked to the network topology of the printed structures This work provided insight on employing (bio)printing in the production of carriers with reproducible and controlled pore area, able to incorporate cell-derived secretome and to be quickly tailored to the patient's lesions.