3D Printed Engineered Living Materials with Genetically Programmed Mechanical Properties and Bioproduction Performance for the Design of Functional Objects and Therapeutic Delivery Platforms

Abstract

The synergy of synthetic biology and materials science yields innovative strategies to find alternative approaches for environmental, medical, and manufacturing challenges. Among these approaches, Engineered Living Materials (ELMs) stand out as a promising platform. ELMs, are a distinctive class of smart materials, which are synthetic living systems where genetically modified microorganisms are integrated into a polymer network, forming functional objects. The material properties and applications are determined by the cellular platform and the encapsulating polymer network. Nevertheless, gaps still exist in the seamless integration of biotic (cellular) and abiotic (polymer) components into a singular material, followed by their assembly into devices and machines. Herein, two different biocompatible polymer networks were developed including (i) a protein-based composite, bovine serum albumin (BSA) – poly (ethylene glycol) diacrylate (PEGDA), and (ii) a synthetic matrix comprising PEGDA-glycerol. These photocurable polymer networks were designed for processing ELMs in light-based 3D printing technologies. The relationships between embedded microorganisms and surrounding polymer matrices were investigated with respect to microbial viability, microbial proliferation behavior, bioproduction capacity, and mechanical properties of ELMs. Subsequently, the interactions between engineered microbial metabolites (L-dopa, betaxanthin, and proteinase A) and protein-based (BSA-PEGDA) polymer matrix were utilized to program mechanical stiffness and degradation time points as desired of 3D printed ELM objects. In an alternative strategy, the polymer concentration of the synthetic matrix (PEGDA-Glycerol) was adjusted to tune the toughness and moduli of 3D printed ELM bioreactors. Finally, an innovative approach toward ELMs for advanced drug delivery was developed using metabolically engineered probiotic strains and 3D printed medical stents. These ELM stents were designed to detect inflammatory biomarkers and initiate responses through the secretion of anti-inflammatory small molecules. This strategy presents a substantial opportunity for facilitating long-term, localized delivery.