García del Rio, LorenaDíaz Rodríguez, PatriciaPedersen, Gabriel KristianChristensen, DennisLandín Pérez, Mariana2022-09-192022-09-192022Garcia‐del Rio, L., Diaz‐Rodriguez, P., Pedersen, G. K., Christensen, D., & Landin, M. (2022). Sublingual boosting with a novel mucoadhesive thermogelling hydrogel following parenteral CAF01 priming as a strategy against chlamydia trachomatis. Advanced Healthcare Materials, 11(11). doi:10.1002/adhm.2021025082192-2640http://hdl.handle.net/10347/29227Chlamydia trachomatis is the most prevalent sexually transmitted disease of bacterial origin. The high number of asymptomatic cases makes it difficult to stop the transmission, requiring vaccine development. Herein, a strategy is proposed to obtain local genital tract immunity against C. trachomatis through parenteral prime and sublingual boost. Subcutaneous administration of chlamydia CTH522 subunit vaccine loaded in the adjuvant CAF01 is combined with sublingual administration of CTH522 loaded in a novel thermosensitive and mucoadhesive hydrogel. Briefly, a ternary optimized hydrogel (OGEL) with desirable biological and physicochemical properties is obtained using artificial intelligence techniques. This formulation exhibits a high gel strength and a strong mucoadhesive, adhesive and cohesive nature. The thermosensitive properties of the hydrogel facilitate application under the tongue. Meanwhile the fast gelation at body temperature together with rapid antigen release should avoid CTH522 leakage by swallowing and increase the contact with sublingual tissue, thus promoting absorption. In vivo studies demonstrate that parenteral-sublingual prime-boost immunization, using CAF01 and OGEL as CTH522 vaccine carriers, shows a tendency to increase cellular (Th1/Th17) immune responses when compared to mucosal or parenteral vaccination alone. Furthermore, parenteral prime with CAF01/CTH522 followed by sublingual boosting with OGEL/CTH522 elicits a local IgA response in the genital tracteng© 2022 The Authors. Advanced Healthcare Materials published by Wiley-VCH GmbH. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposeshttp://creativecommons.org/licenses/by-nc/4.0/Cationic adjuvant liposomesMucoadhesive and thermosensitive platformsMucosal vaccinationPolymeric networksPrime-boost strategySystemic and sublingual immunizationjournal article10.1002/adhm.2021025082192-2659open access