Mechanical properties evolution of a PLGA-PLCL composite scaffold for ligament tissue engineering under static and cyclic traction-torsionin vitroculture conditions

Abstract

This study aims to investigate the in vitro degradation of a poly(L-lactic-co-glycolic acid)-poly(L-lactic-co-ϵ-caprolactone) (PLGA-PLCL) composite scaffold's mechanical properties under static culture condition and 2 h period per day of traction-torsion cyclic culture conditions of simultaneous 10% uniaxial strain and 90° of torsion cycles at 0.33 Hz. Scaffolds were cultured in static conditions, during 28 days, with or without cell seeded or under dynamic conditions during 14 days in a bioreactor. Scaffolds' biocompatibility and proliferation were investigated with Alamar Blue tests and cell nuclei staining. Scaffolds' mechanical properties were tested during degradation by uniaxial traction test. The PLGA-PLCL composite scaffold showed a good cytocompatibility and a high degree of colonization in static conditions. Mechanical tests showed a competition between two process of degradation which have been associated to hydrolytic and enzymatic degradation for the reinforce yarn in poly(L-lactic-co-glycolic acid) (PLGA). The enzymatic degradation led to a decrease effect on mechanical properties of cell-seeded scaffolds during the 21st days, but the hydrolytic degradation was preponderant at day 28. In conclusion, the structure of this scaffold is adapted to culture in terms of biocompatibility and cell orientation (microfiber) but must be improved by delaying the degradation of it reinforce structure in PLGA.

Static and Cyclic Mechanical Loading of Mesenchymal Stem Cells on Elastomeric, Electrospun Polyurethane Meshes

“…Bars correspond to the mean 6 standard deviation for n 5 2 samples, except for small diameter fiber, static load, where n 5 1. While studies have been performed to independently evaluate the effect of the diameters of electrospun fibers on cell phenotype in the absence of mechanical forces [16,17] and to probe cellular responses to mechanical stimulation on fibrous supports [21,24,29], the combined effect of fiber diameter and mechanical stimulation has not been previously examined. In this study, cell number was comparable across all loading conditions on meshes of both fiber diameters, indicating that mechanical stimulation did not undermine cell adhesion or proliferation.…”

Advancements in scaffold for treating ligament injuries; in vitro evaluation

“…The most well-known examples of these materials are polyglycolic acid (PGA), polylactic acid (PLA), poly(ε-caprolactone) (PCL), poly(L-lactic acid) (PLLA), poly(lactide-co-glycolic acid) (PLGA), poly(Lcaprolactone-caprolactone)(poly(L-lactide-co-epsilon-caprolactone), PLCL), etc. [1,[51][52][53] (Table 1). However, synthetic polymer scaffolds have low cytocompatibility; hence, to compensate for this shortcoming, other components like COL, hyaluronic acid, CS, and nanofiber crystals are frequently included in synthetic scaffolds.…”

“…However, synthetic polymer scaffolds have low cytocompatibility; hence, to compensate for this shortcoming, other components like COL, hyaluronic acid, CS, and nanofiber crystals are frequently included in synthetic scaffolds. [52,54,55] These composite scaffolds use the benefits offered by both natural and synthetic polymers, which ultimately leads to improved biocompatibility and enhanced mechanical qualities. (An overview of the pertinent features of common material structures used in scaffold synthesis is summarized in Tables 2 and 3).…”

“…However, PLGA must be supplemented with substances that delay its degradation to improve scaffold properties further. [52,155] It is worth noting that the FDA has approved PLGA for use in humans. Nevertheless, the major drawback of PLGA as a synthetic polymer is its lack of biological properties that can promote cell adhesion and proliferation.…”