Poly(lactic-co-glycolide) based biodegradable electrically and magnetically active microenvironments for tissue regeneration applications

Polymer scaffolds are playing an increasing role in tissue engineering (TE), although there is still a need to improve their biomimicry of cellular microenvironments, by having smart scaffolds with an active response, which can improve tissue regeneration. This work reports on the novel combination of poly(lactic-co-glycolide) (PLGA) with the ionic liquid (IL) choline bis(trifluoromethylsulfonyl)imide ([Chol][TFSI]) or with iron oxide nanoparticles (Fe3O4, NP) in order to achieve biodegradable scaffolds with electroactive and magnetoactive response, respectively. The composites were processed into fiber and film morphologies. PLGA + IL fibers present diameters between 1.92 and 3.26 mu m, decreased mechanical stiffness and elongation at yield with respect to the pristine polymer, and some fiber concentrations are not biocompatible. PLGA + IL films present a mean roughness 6.58 nm, increased mechanical stiffness with respect to the pristine polymer and decreased elongation at yield. The inclusion of IL increased the electrical conductivity of the polymer by 4 orders or magnitude. The diameter of PLGA + Fe3O4 fibers ranged from 0.62 to 1.36 mu m, show an effective magnetic NP content yield between 52 and 78%, decreased stiffness and increased elongation at yield. PLGA + Fe3O4 films show a mean roughness of 5.07 nm, effective NP content yield between 77 and 97%, increased stiffness and elongation at yield. Cytotoxicity assays indicate that the PLGA + Fe3O4 materials are suitable for biomedical applications, independently of the filler content and morphology, whereas the IL containing samples are non-cytotoxic only in film morphology up to 5% wt. IL content. Finally, it is demonstrated that dynamic magneto mechanical stimulation of the PLGA + Fe3O4 samples allows the acceleration of the degradation rate of the samples.

Automated summary

Polymer scaffolds are widely used in tissue engineering, but their biomimicry needs improvement for better tissue regeneration. This study combines poly(lactic-co-glycolide) with an ionic liquid or iron oxide nanoparticles to create biodegradable scaffolds with electroactive or magnetoactive response. The inclusion of the ionic liquid or nanoparticles alters the mechanical properties and surface morphology of the polymer, and the biocompatibility of the materials depends on the type and content of the fillers.