Hydrogels are unique materials composed of a hydrophilic polymeric network with the ability to absorb and retain large amounts of water, reason why they are being widely used for wound dressings. However, hydrogels do not offer the possibility to quantitatively evaluate the regeneration process. Thus, the objective of this work is to develop a multifunctional hydrogel able to host skin cells (e.g. fibroblasts) and sense temperature as a relevant parameter during skin regeneration. The multifunctional hydrogel consists of an interpenetrated polymer network of alginate (Alg) and gelatin (gel) as a scaffold for the 3D culture of skin cells and incorporating gold nanoparticles (Au NPs) to confer electrical conductivity. The hydrogels are easily formed by mixing alginate, gelatine and Au NPs, placing the mixture in a mould and crosslinking the hydrogel using Ca2+ ions. Preliminary results show that electrical conductivity of the hydrogels linearly changes with temperature in the range 35-45, which clearly indicates they can be successfully used to in-situ monitor the temperature of the cell-laden hydrogel. The present methodology can pave the way to a new generation of soft electronic devices embedded into 3D scaffolds.

Eduardo Pérez1,2,*, Angela Esplugues3,4, Yana Heyvaert3,4, Maximilan Jergitsch3,4, Herminio Martinez5, Maziar Ahmadi6, Miguel Angel Mateos3,4, José García-Torres1,2,*

1 Biomaterials, Biomechanics and Tissue Engineering Group, Department of Materials Science and Engineering, Universitat Politècnica de Catalunya (UPC), 08019, Barcelona, Spain.

2 Barcelona Research Center in Multiscale Science and Engineering, Universitat Politècnica de Catalunya-Barcelona Tech, 08019, Barcelona, Spain

3 Bioengineering Institute of Technology, Universitat Internacional de Catalunya, Josep Trueta, 08195 Sant Cugat del Vallès, Barcelona, Spain.

4 Department of Basic Sciences, Faculty of Medicine and Health Science, Universitat Internacional de Catalunya, JosepTrueta, 08195 Sant Cugat del Vallès, Barcelona, Spain

5 EPIC (Energy Processing Integrated Circuits) Group, Electronic Engineering Department, Universitat Politècnica de Catalunya (UPC), 08019, Barcelona, Spain.

6 Micro and Nanotechnologies group, Electronic Engineering Department, Universitat Politècnica de Catalunya (UPC), 08034, Barcelona, Spain.

email: eduardo.perez.del.rio@upc.edu; jose.manuel.garcia-torres@upc.edu