Fascia Bioprinting and Tensile Testing
The study of human tissues and tissue-engineered materials is crucial to the development of regenerative medicine, seeking tissue restoration and replacement.
I first came across fascia tissue while studying and practicing traditional acupuncture. I was intrigued by the striking resemblance of the fascia ‘trains’ (connecting paths between body parts) and Chinese meridians…The present study does not focus on this similarity and its significance yet, taking us back to more fundamental questions: how does fascia work mechanically? What is its composition and structure? Can we imitate it?
The evaluation of soft tissue biomechanical properties is of paramount importance not only for a comprehensive understanding of human physiology and physiopathology but also in the research and development of bio-compatible artificial tissues with viscoelastic properties.
Fascia is a multi-layered structure of connective tissue, including collagen fibers and elastic fibers. Fascia is everywhere in the body, from the microscopic level (in all membranous structures including the cell) to the macroscopic level, wrapping muscles and organs and separating them. It is a viscoelastic tissue, and it contains an abundance of mechanoreceptors (proprioceptors) and sensory receptors (nociceptors), vascular and lymphatic feeding channels. Fascia plays important roles in movement and communication: its functions include transmission of forces, proprioceptive communication, reduction of muscle friction, shock absorption, elasticity in movement, and more.
The functionality and health of the fascia is characterized by specific composition and structure, which includes the direction and organization of the fibers in it. Changes in the chemical composition, density and structure of the fascia may cause a reduction in its ability to slide between muscle and skin, between organs, between muscles. This causes pain and poor transmission of forces between the muscles.
The mechanical properties of the fascia are of paramount importance in the health of the musculoskeletal system, its training, and the treatment of myopathy.
The research progresses in two directions: 3D printing of biomimetic fascia samples and the characterization of their mechanical properties by tensile testing.
Several biological samples are printed using INKREDIBLE+ 3D printer, with different material formulations and filament structures. Then the samples are tested: a custom uniaxial tensile testing system, namely BRAUTENSE, was designed and built.
BRAUTENSE enables the measurement of real-time displacement as a function of load; the specimen may be tested at either room temperature conditions or in simulated biological environments by immersion in a temperature-controlled fluid. The system includes tailored clamps with interchangeable 3D-printed gripping inserts. BRAUTENSE can be easily customized to perform different types of tensile experiments for the characterization of viscoelastic materials.
Experimental results will be presented soon.
For more information:
Salih, A., Roth, N., Buganim, O. and Pelosi, A.D. A Low-Cost Open-Source Uniaxial Tensile System for Soft Tissue Testing, Hardware, 2, 292–305 (2024). https://doi.org/10.3390/hardware2040015
