Penn State Researchers Develop Novel Biomaterial Mimicking Extracellular Matrices

Researchers at Penn State have created a new biomaterial that imitates the behavior of extracellular matrices (ECMs) in biological tissues. This innovation could potentially advance fields such as regenerative medicine, disease modeling, and soft robotics. 

The team developed a bio-based, "living" material with self-healing properties that replicates the biological response of ECMs to mechanical stress. This acellular material, called LivGels, addresses limitations of previous synthetic hydrogels that lacked the desired combination of mechanical responsiveness and biological mimicry.

Amir Sheikhi, senior author of the paper published in Materials Horizon, explained, "We developed a cell-free—or acellular—material that dynamically mimics the behavior of ECMs, which are key building blocks of mammalian tissues that are crucial for tissue structure and cell functions."

The LivGels are composed of "hairy" nanoparticles made from nanocrystals with disordered cellulose chains at the ends. These nanoparticles bond with a biopolymeric matrix of modified alginate, a natural polysaccharide found in brown algae. This design allows for dynamic bonding and strain-stiffening behavior, mimicking ECMs' response to mechanical stress.

Sheikhi noted, "These materials need to replicate nonlinear strain-stiffening, which is when ECM networks stiffen under strain caused by physical forces exerted by cells or external stimuli." The material also replicates self-healing properties necessary for tissue structure and survival.

The researchers used rheological testing to measure how rapidly the LivGels recovered their structure after high strain. This design approach allowed fine-tuning of the material's mechanical properties to match those of natural ECMs.

Potential applications for LivGels include scaffolding for tissue repair and regeneration, simulating tissue behavior for drug testing, creating realistic environments for studying disease progression, 3D bioprinting customizable hydrogels, and developing soft robotics with adaptable mechanical properties.

The team's next steps include optimizing LivGels for specific tissue types, exploring in vivo applications for regenerative medicine, integrating LivGels with 3D bioprinting platforms, and investigating potential uses in dynamic wearable or implantable devices.