The effect of introduction of filament shift on degradation behaviour of PLGA- and PLCL-based scaffolds fabricated via additive manufacturing


Walejewska E., Idaszek J., Heljak M., Chlanda A., Choinska E., Hasirci V. N. , ...Daha Fazla

POLYMER DEGRADATION AND STABILITY, cilt.171, 2020 (SCI İndekslerine Giren Dergi) identifier identifier

Özet

The degradation rate of polyester scaffolds has been emphasised as one of the main areas of concern in bone tissue engineering. In ideal conditions, the degradation of polymeric constructs should match regeneration of the injured tissue. Thus, there is an imperative need to strictly define and understand determinants influencing the degradation rate of scaffolds. In this study, we focused on the effect of filament shift introduction on degradation behaviour of the polymeric-based scaffolds. The poly(L-lactide-co-glycolide) (PLGA), poly(L-lactide-co-epsilon-caprolactone) (PLCL) and their tricalcium-phosphateloaded (TCP) composites containing 20 and 40 wt% of filler, were utilized to fabricate constructs using modified fused deposition modeling (FDM). The scaffolds were designed with filament lay-down pattern of 0 degrees/90 degrees and with or without the modifications of filament distance in n+2 layer, shifted and nonshifted constructs were obtained, respectively. To investigate the degradation profile, the change of mass, pH, water absorption and initial molecular weight (M-w0) loss was observed during the degradation study in phosphate buffered saline (PBS) at 37 degrees C for up to 48 weeks. The scaffold morphology was evaluated utilizing scanning electron microscopy (SEM) and the visualization of the topography was performed utilizing atomic force microscopy (AFM). Surface area to volume ratio (SVR) and porosity were determined using micro-computed tomography (mu CT). The fluid flow simulations were used to define the permeability of two investigated groups of scaffolds. The results of this study clearly demonstrate the accelerating effect of filament shift introduction on degradation behaviour in the scaffolds with similar porosity and SVR. The decrease of M-w0 was significantly higher in case of all shifted samples. We assume that faster degradation of shifted constructs may be attributed to their tortuosity, making them less permeable and prone to the degradation, as the result of the accumulation of acidic products in the tortuous architecture of the samples. Thus, the effect of introduction of filament shift into scaffold architecture comprise an attractive approach to influence the degradation rate in case of bone regeneration with the use of polyesters scaffolds. (C) 2019 Elsevier Ltd. All rights reserved.