Transactions on Additive Manufacturing Meets Medicine
Vol. 7 No. S1 (2025): Trans. AMMM Supplement
https://doi.org/10.18416/AMMM.2025.25062081

Scaffolds, Implants and Drug Delivery Systems, ID 2081

Engineering of a Polycaprolactone-Stabilized Alginate Hydrogel for 3D Bioprinting of Patient-Specific Implants enabling Sustained Local Dexamethasone Delivery in Inner Ear Therapy

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Verena Scheper (1) Clinic of Otorhinolaryngology; 2) Cluster of Excellence "Hearing4all"; 3) Lower Saxony Center for Biomedical Engineering, Implant Research and Development; All Hannover Medical School, Hannover, Germany), Yanjing Luo (1) Clinic for Otorhinolaryngology ; 2) Cluster of Excellence "Hearing4all"; 3) Lower Saxony Center for Biomedical Engineering, Implant Research and Development; all Hannover Medical School, Hannover, Germany), Thomas Lenarz (1) Clinic for Otorhinolaryngology ; 2) Cluster of Excellence "Hearing4all"; 3) Lower Saxony Center for Biomedical Engineering, Implant Research and Development; all Hannover Medical School, Hannover, Germany), Gerrit Paasche (1) Clinic for Otorhinolaryngology ; 2) Cluster of Excellence "Hearing4all"; 3) Lower Saxony Center for Biomedical Engineering, Implant Research and Development; all Hannover Medical School, Hannover, Germany), Jan Drexler (Institute for Multiphase Processes, Leibniz University Hannover, Hannover, Germany.), Gerald Dräger (Institute of Organic Chemistry, Leibniz University Hannover, Hannover, Germany), Hongzheng Zhang (1) Department of Otolaryngology Head & Neck Surgery; 2) Ear Research Institute; both Zhujiang Hospital, Southern Medical University, Guangzhou, China), Jie Tang (1) Department of Otolaryngology Head & Neck Surgery; 2) Ear Research Institute, 3) Department of Physiology, School of Basic Medical Science; 4) Key Laboratory of Mental Health of the Ministry of Education; all Southern Medical University, Guangzhou, China)

Copyright (c) 2025 Verena Scheper, Yanjing Luo, Thomas Lenarz, Gerrit Paasche, Jan Drexler, Gerald Dräger, Hongzheng Zhang, Jie Tang

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This work is licensed under a Creative Commons Attribution 4.0 International License.

Abstract

There is an unfulfilled need for local inner ear therapy to treat hearing disorders. We developed a silicone implant enabling drug diffusion from the middle ear into the inner ear. This implant is precisely tailored to conform to the unique anatomical contours of each patient's round window niche, thereby facilitating controlled diffusion of therapeutic agents into the inner ear. To improve the approach biodegradation of the implant would be beneficial to avoid the potential need of explanting the drug delivery device. Alginate hydrogels, while well-established for their cytocompatibility and biodegradability, are inherently limited by insufficient viscosity and suboptimal mechanical integrity, restricting their applicability in 3D bioprinting. To overcome these deficiencies, we engineered a composite hydrogel system through the incorporation of polycaprolactone particles (PCL) to modifying the printability.  


The composite material was 3D printable and compression tests and rheological tests determined the elastic properties of the hydrogel and the structural stability under a certain load.  Investigations into swelling kinetics and morphological stability under simulated physiological conditions substantiated the material's durability and functional integrity within 7 days and subsequent degradation over time. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) revealed a homogeneous microarchitecture conducive to controlled drug diffusion, as corroborated by in vitro release kinetics of dexamethasone quantified through high-performance liquid chromatography (HPLC). Cytotoxicity tests demonstrated biocompatibility, and the dexamethasone-loaded hydrogel elicited anti-inflammatory responses in vitro.


The PCL-reinforced alginate hydrogel is a promising platform for the fabrication of personalized, biodegradable, and pharmacologically active implants.

Article Details

How to Cite

Scheper, V., Luo, Y., Lenarz, T., Paasche, G., Drexler, J., Dräger, G., … Tang, J. (2025). Engineering of a Polycaprolactone-Stabilized Alginate Hydrogel for 3D Bioprinting of Patient-Specific Implants enabling Sustained Local Dexamethasone Delivery in Inner Ear Therapy. Transactions on Additive Manufacturing Meets Medicine, 7(S1), 2081. https://doi.org/10.18416/AMMM.2025.25062081

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