Hybrid biodegradable electrospun scaffolds based on poly(l-lactic acid) and reduced graphene oxide with improved piezoelectric response

• DOI: 10.1038/s41428-022-00669-1
• Publication Date: 2022-07-13T12:07:25Z
• Authors: Igor O. Pariy; Roman V. Chernozem; Polina V. Chernozem; Yulia R. Mukhortova; Andre G. Skirtach; Vladimir V. Shvar...; Doru C. Lupascu; Maria A. Surmeneva; Sanjay Mathur; Roman A. Surmenev
• Keywords: Biodegradable polymer

Piezoelectric poly-L-lactide (PLLA) is a biodegradable polymer used in various biomedical applications. However, tailoring and controlling the structure of PLLA to enhance its piezoelectric response remains a challenge. In this work, extensive characterization was performed to reveal the effect of the reduced graphene oxide (rGO) content (0.2, 0.7, and 1.0 wt%) on the morphology, structure, thermal and piezoelectric behavior of PLLA scaffolds. Randomly oriented homogeneous fibers and a quasi-amorphous structure for pure PLLA and hybrid PLLA-rGO scaffolds were revealed. The addition of rGO affected the molecular structure of the PLLA scaffolds: for example, the number of polar C=O functional groups was increased. Increasing the content of rGO to 1 wt% resulted in decreased glass transition and melting temperatures and increased the degree of crystallinity of the scaffolds. The addition of 0.2 wt% rGO enhanced the effective local vertical and lateral piezoresponses by 2.3 and 15.4 times, respectively, in comparison with pure PLLA fibers. The presence of the shear piezoelectric alpha-phase (P2(1)2(1)2(1)) in uniaxially oriented PLLA fibers and C=O bond rotation in the polymer chains explained the observed piezoresponse. Thus, this study revealed routes to prepare hybrid biodegradable scaffolds with enhanced piezoresponse for tissue engineering applications.