Controlled Release Systems for Nanoparticles carrying RNAs

​F​ollowing this design approach, we employed agarose as a hydrogel matrix that was 3D printed via extrusion to form the shell of a matrix encapsulating a core of Pluronic F127 carrying siRNA/Lipofectamine RNAiMax nanoparticles. Dr. Dina Mahmoud could control the release of RNA nanoparticles by the printing design, i.e. by the number of agarose layers as well as the distance between the printed hydrogel strands.​

team

​Dr. Dina B. Mahmoud developed this 3D printing approach.

literature

Mahmoud D , Wölk C & Schulz‐Siegmund M Fabrication of 3d printed, core‐and‐shell implants as controlled release systems for local sirna delivery. Adv Healthcare Materials. 2023;12(31). doi: 10.1002/adhm.202301643

funding​

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​​In cooperation with ​​JProf. Dr. Michael C. Hacker we employ cross-linked gelatin microparticles for loading and release of siRNA-carrying nanoparticles. For nanoparticle loading, nanoparticles are dispersed in a small volume of medium and mixed with dried cross-linked gelatin microparticles in order to homogeneously load the nanoparticles into the microparticles.

Polyelectrolyte multilayers, more precise complexes between alternating polycation and polyanion layers, allow multiple possibilities to design different materials for pharmaceutical use. It is possible to produce surface coating as well as flexible films using automatized production as well as different combinations of polyelectrolytes. The fascination of polyelectrolyte multilayers is the ability to functionalize them with additional materials using electrostatic interactions. In our projects we functionalize polyelectrolyte multilayers with nucleic acid – lipid nanoparticles to design novel local release systems for nucleic acid therapeutics. 

Various techniques are used to understand the structure of the polyelectrolyte multilayers, e.g. atomic force microscopy, fluorescence microscopy, water contact angle measurements, x-ray techniques. The work also includes the investigation of new loading strategies for the polyelectrolyte multilayers, like in our recent work ink-jet 3D printing. The hypothetical applications are can be seen in regenerative medicine, but also in other nucleic acid therapies. In a novel project we plan to apply the technique on urethral stents.

literature

Krabbes M, Kieckhöfer M, Schmidt C, et al. Inkjet printing of lipoplexes: A feasibility study. Applied Materials Today 2025; 44: 102699. doi: 10.1016/j.apmt.2025.102699

Krabbes M, Kampik V, Krieghoff J, et al. Development and functionality analysis of lipoplex-loaded polysaccharide-based surface coatings for local nucleic acid delivery. Int J Pharm 2025; 673: 125330. doi: 10.1016/j.ijpharm.2025.125330

Husteden C, Doberenz F, Goergen N, et al. Contact-Triggered Lipofection from Multilayer Films Designed as Surfaces for in Situ Transfection Strategies in Tissue Engineering. ACS Appl Mater Interfaces 2020; 12: 8963–8977.​ doi: 10.1021/acsami.9b18968

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