Genetically engineered elastin-like recombinamers with sequence-based molecular stabilization as advanced bioinks for 3D bioprinting

The versatility of 3D bioprinting techniques has demonstrated great potential for the development of artificial engineered tissues that more closely resemble native tissues. Despite this, challenges remain as regards the search for new bioinks that embrace all the complex parameters that this technique demands. In an attempt to develop such an advanced material, a novel smart material based on elastin-like recombinamers (ELRs) has been developed by molecularly programming its sequence to exhibit a sequential three-stage gelation process, thus providing printing attributes. The thermoresponsive behavior of the ELR is exploited for the deposition of well-controlled fibres on a platform heated to 37 °C, and its recombinant nature ensures batch-to-batch reproducibility and its applicability to a desired target tissue by the introduction of selected bioactive amino-acid sequences into its molecular chain. The biocompatible nature of the ELR enables the printing of loaded cells while providing a protective environment as part of the printing process. Thus, HFF-1 cells were found to be able to proliferate within the printed structures upon culture, displaying their natural morphology. The results of this work highlight the applicability and novelty of the bioprinting of biomimetic ELR-based structures for advanced applications.