Piezoelectric Electrospun Fibrous Scaffolds for Bone, Articular Cartilage and Osteochondral Tissue Engineering

Abstract

Osteochondral tissue (OCT) related diseases, particularly osteoarthritis, number among the most prevalent in the adult population worldwide. However, no satisfactory clinical treatments have been developed to date to resolve this unmet medical issue. Osteochondral tissue engineering (OCTE) strategies involving the fabrication of OCT-mimicking scaffold structures capable of replacing damaged tissue and promoting its regeneration are currently under development. While the piezoelectric properties of the OCT have been extensively reported in different studies, they keep being neglected in the design of novel OCT scaffolds, which focus primarily on the tissue's structural and mechanical properties. Given the promising potential of piezoelectric electrospun scaffolds capable of both recapitulating the piezoelectric nature of the tissue's fibrous ECM and of providing a platform for electrical and mechanical stimulation to promote the regeneration of damaged OCT, the present review aims to examine the current state of the art of these electroactive smart scaffolds in OCTE strategies. A summary of the piezoelectric properties of the different regions of the OCT and an overview of the main piezoelectric biomaterials applied in OCTE applications are presented. Some recent examples of piezoelectric electrospun scaffolds developed for potentially replacing damaged OCT as well as for the bone or articular cartilage segments of this interfacial tissue are summarized. Finally, the current challenges and future perspectives concerning the use of piezoelectric electrospun scaffolds in OCT regeneration are discussed.

Keywords: articular cartilage; bone; electrospinning; osteochondral tissue; piezoelectric fibrous scaffolds; tissue engineering.

Figure 1

Piezoelectric electrospun fibrous scaffolds for osteochondral tissue engineering applications.

Figure 2

Piezoceramics used for TE applications [51,52,53,54,55]. It should be noted that the chemical structure of piezoceramics is variable, depending mainly on the fabrication process used. Reproduced from Burns and Dolgos [51] with permission from the Centre National de la Recherche Scientifique (CNRS) and The Royal Society of Chemistry. Reprinted from Espitia et al. [52], Copyright 2012, by permission from Springer Nature. Reprinted with permission from Král et al. [53], Copyright 2000 by the American Physical Society.

Figure 3

Chemical structures of the main piezoelectric polymers used for TE applications.

Figure 4

Chemical structures of the most common crystalline phases of PVDF: ((a)—α phase, (b)—β phase, (c)—γ phase) and (d) PVDF-TrFE piezoelectric polymers.