Development of multifunctional nanostructured surfaces for the improvement of blood-contacting devices

• Applicant: Thi Huong Nguyen, Ph.D.
• Subject Area: Synthesis and Properties of Functional Materials ; Coating and Surface Technology ; Biochemistry ; Biomaterials ; Biomedical Systems Technology ; Biophysics ; Primary Shaping and Reshaping Technology, Additive Manufacturing
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 567384216

Platelet transfusions are essential in trauma care but face limitations due to short shelf life, pH instability, di-2-ethylhexyl phthalate (DEHP) plasticizer releasing, and contamination risks. Blood-contacting devices also risk thrombosis through platelet adhesion. This project proposes a novel blood storage bag by integrating multifunctional nanoporous agarose hydrogel onto DEHP-free Ethylene Vinyl Acetate (EVA) and Thermoplastic Elastomer (TPE) bags- promising alternatives to current DEHP-based PVC bags. Previous studies show that micro/nanostructured, platelet-like shapes mimicking endothelial matrices reduce platelet adhesion and activation. However, scaling these structures for blood bags is hindered by fabrication challenges. We observed that agarose hydrogel naturally forms nanopores resembling engineered surfaces, offering a cost-effective, scalable alternative. We will fine-tune agarose pore size by adjusting gelation parameters (concentration, temperature, pH, ionic strength, crosslinkers) to achieve platelet-like shapes that optimize anti-adhesive behavior. Further, imprinting microstructures onto agarose will allow assessment of synergistic effects from combined imprinted and intrinsic nanostructures using FluidFM technology. To enhance antimicrobial properties, we will incorporate silver (Ag), magnetite (Fe₃O₄) nanoparticles, and chitosan into the structured agarose. Heparin will be added to further suppress platelet activation. For practical application, these hydrogels must adhere to EVA/TPE surfaces. Unlike DEHP-based PVC or PE, which limit gas exchange and encourage bacterial growth, EVA and TPE are biocompatible, gas-permeable, and DEHP-free- ideal for platelet storage. We will develop thin agarose composite coatings on EVA/TPE, addressing the challenge of bonding hydrophilic hydrogels to hydrophobic polymers through surface modification. Alternative hydrogels and synthetic polymers will also be explored to enhance mechanical strength and processing precision. This project introduces three key innovations: i) hydrogel micro/nanostructures of platelet-like shapes to prevent platelet activation and eliminate DEHP leaching, ii) antimicrobial hydrogel composites with nanoparticles/chitosan, and iii) structured agarose coatings on EVA/TPE for superior gas exchange and biocompatibility. The intrinsic nanopores of agarose simplify fabrication, enabling scalable application not only in blood storage but also in medical tubing, food packaging, and other plastic-based uses.

• DFG Programme: Research Grants