A Polycaprolactone (PCL)-Supported Electrocompacted Aligned Collagen Type-I Patch for Annulus Fibrosus Repair and Regeneration.

Deformity or fissure within the annulus fibrosus (AF) lamellar structure often results in disc herniation leading to the extrusion of nucleus pulposus (NP), which pushes the adjacent nerve, causing low back pain. Low back pain, frequently associated with the degeneration of the intervertebral disc (IVD), affects around 80% of the population worldwide. The difficulty in mimicking the unique structural characteristics of the native AF tissue presents several challenges to the tissue engineering field for the development of the long-term effective therapeutic strategy for AF tissue regeneration.

Multifarious Fabrication Approaches of Producing Aligned Collagen Scaffolds for Tissue Engineering Applications.

Aligned tissue architecture is a basic proviso for several organs and tissues like intervertebral discs, tendons, ligaments, muscles, and neurons, which comprises type-I collagen as an eminent extracellular matrix (ECM) protein. Exploiting type-I collagen for the biofabrication of aligned constructs via different approaches is becoming apparent, as it comprises a major fraction of connective tissue, exhibits abundance in ECM, and displays poor antigenicity and immunogenicity, along-with the ease of remodelling adaptability. Collagen hydrogels or composite scaffolds with uniaxial fibril alignment or unidirectional pore architecture having different sizes and densities are being fabricated using electrical, mechanical, and freeze-drying processes which are applicable for tissue engineering and regenerative purposes.