Functionalization of magnetotactic bacteria with gold Nanoprisms. A Route to novel photothermal agents Cerezo Collado, Laura Gómez Vázquez, Emilio Fernández Afonso, Yilian González Garnica, Ana Isabel Gutiérrez, Lucia M. de la Fuente, Jesús Abad, Ana Gubieda, Alicia G. Fernández Gubieda, Mª Luisa Domínguez Vera, José Manuel Garcés Robles, Víctor Jesús magnetic bacteria gold nanoprisms EPS photothermal therapy biohybrid microrobots This work was funded by the Ministerio de Universidades (MCIU), the Agencia Estatal de Investigación (AEI) and Fondo Europeo de Desarrollo Regional (FEDER) through the projects PID2019- 111461 GB-I00 to J.M.D-V. and PID2023-146448OB-21 to M.L.F-G., A.A. and A.G.G. Also, by the Basque Government through the project IT-1479-22. Project CNS2023-144321 funded by MICIU/AEI/10.13039/501100011033 and NextGenerationEU/PRTR, and Fondo Social del Gobierno de Aragón (grupo DGA E15-23R) are also acknowledged. V.G. acknowledges for the postdoctoral contract within the Margarita Salas 2021 program (Universidad de Granada-Ministerio de Universidades-Next Generation EU). Y.F-A. thanks Santander-Universidad Zaragoza Fellowship program for her PhD position. Authors would like to acknowledge the use of Servicio General de Apoyo a la Investigación-SAI, Universidad de Zaragoza. The authors also wish to acknowledge the Scientific Instrumentation Centre (CIC) of the University of Granada for access to its facilities. Magnetotactic bacteria offer promising biomedical applications due to their unique ability to synthesize magnetic nanoparticles and their natural magnetotaxis, which enables their controlled navigation in fluids. They also serve as a platform for integrating synthetic nanomaterials, adding new functionalities and increasing their potential in biomedicine. This study explores the functionalization of Magnetospirillum gryphiswaldense (MSR-1) with gold nanoprisms (AuNPR). The attachment of AuNPR to the outer surface of MSR-1 was achieved by two synthetic approaches: i) direct attachment of AuNPR to MSR-1 to produce MSR-AuNPR and ii) pre-coating AuNPR with exopolysaccharides (EPS) from Lactobacillus plantarum (Lp) or Pseudomonas aeruginosa (Pa), resulting in Lp@AuNPR and Pa@AuNPR, which were then bound to MSR-1, thereby producing MSR-Lp@AuNPR and MSR-Pa@AuNPR. When exposed to near-infrared (NIR) light (λ = 1064 nm), the functionalized bacteria were able to produce a temperature increase ranging from 8 °C to 10 °C, thereby substantiating their capacity for photothermal therapy. Viability of the functionalized bacteria was also studied. While MSR-1 viability exhibited a greater decrease upon direct AuNPR attachment, EPS-coated AuNPR were able to decrease this toxic effect. This finding suggests that EPS coatings enhance bacterial compatibility and system stability. The study also confirmed that the release of AuNPR from MSR-1 remained minimal under biological pH conditions, indicating a high degree of conservation of the MSR-AuNPR, MSR-Lp@AuNPR, and MSR-Pa@AuNPR systems. Furthermore, the structural integrity of the functionalized bacteria was maintained after prolonged storage at 4 °C. These results underscore the augmented biomedical potential of magnetotactic bacteria functionalized with AuNPR for photothermal therapy, a combination that integrates their mobility given their intrinsic magnetic properties with an innovative NIR-responsive pathway. 2025-11-18T07:47:00Z 2025-11-18T07:47:00Z 2025-11-06 journal article L. Cerezo-Collado et al. Materials Today Chemistry 50 (2025) 103178. https://doi.org/10.1016/j.mtchem.2025.103178 https://hdl.handle.net/10481/108050 10.1016/j.mtchem.2025.103178 eng info:eu-repo/grantAgreement/EC/FP7/CNS2023-144321 http://creativecommons.org/licenses/by-nc-nd/4.0/ open access Attribution-NonCommercial-NoDerivatives 4.0 Internacional Elsevier