Electro-spun piezoelectric PLLA smart composites as a scaffold on bone fracture: A review.

The intrinsic ability of these scaffold materials to generate piezoelectric currents presents a major proposition for increasing the complexity of the scaffold and facilitating tissue healing. The piezoelectric behavior of bone tissue has been an area of interest for many researchers in the past. However, these properties have not been given much attention in new osteochondral tissue scaffold designs, whereas the established design factors mainly concentrate on the structural and mechanical characteristics of the tissue in question. The main advantages of the piezoelectric electrospun scaffolds in tissue engineering consist in the possibility to reproduce the piezoelectric properties of the fibrous extracellular matrix (ECM) of the tissue and the application of combined electrical and mechanic stimulation in the process of bone tissue regeneration. Poly-l-lactic acid (PLLA) has proved to be a potential biomaterial because of its adjustable mechanical characteristics and the bio-degradable capability for the creation of porous scaffolds with micro/nanostructure designs in various techniques. PLLA-based scaffolds can be altered on their surface or can be incorporated with other polymers either natural or synthetic or bioceramic materials. These modifications and combinations are to introduce improvement or changes in the scaffolds for the improvement of the functional properties that favor bone tissue engineering. In this review, we discussed the properties of PLLA and more particularly, the fracture-repairing activity in bone fracture therapy. It also investigates the interaction of PLLA with other biopolymers or biomaterials to dramatically enhance bone scaffolds' performance.