Elastic scaffolds reinforced stem cell-laden collagen-derived hybrid hydrogels to engineer 3D anisotropic cellular microenvironment

Replicating complex, robust and organized three-dimensional (3D) cellular microenvironments that exist in many human tissues is essential for understanding the cell-matrix interactions and paving the foundation for tissue engineering. However, biofabrication strategies for in vitro modeling such complex, mechanically robust, and 3D anisotropic cell networks by cell-laden hydrogel-scaffolds are far less developed. This work describes 3D anisotropic soft-hard hybrid scaffolds with either single macroscale anisotropy or dual macro-micro-scale anisotropy by incorporating collagen-derived hydrogels with human mesenchymal stem cells (hMSCs) and 3D printed poly(ester amide) (PEA) scaffolds with uniaxial architecture. As a hard scaffold, the uniaxial PEA scaffold endows hybrid constructs with macroscale anisotropy, good elasticity, and mechanical properties. As a soft matrix, methacrylated collagen peptide (COPMA) hydrogel endows hybrid constructs with rapid light response, leading to in situ formation of 3D cellular networks. Magnetic nanoparticles (MNPs) laden COPMA hydrogel endows hybrid constructs with rapid dual light-magnetic response and magnetic-driven dual macro-micro-scale anisotropy. PEA-COPMA constructs act as biocompatible biochemical cues to induce the encapsulated hMSCs to attach and spread between the scaffold and the hydrogel. These encapsulated hMSCs showed improved cell spreading, alignment and differentiation in the dual macro-micro-scaled aligned PEA-COPMA-MNP constructs due to the combination of biochemical and biophysical anisotropic cues. This hybrid manufacturing strategy, which directly incorporates light-magnetic-responsive cell-laden nanocomposite hydrogels with elastic organized scaffolds, shows great potential in developing advanced mechanically reinforced 3D organized in vitro cellular microenvironments.