Design of 3D scaffolds for tissue engineering testing a tough polylactide-based graft copolymer

The aim of this research was to investigate a tough polymer to develop 3D scaffolds and 2D films for tissue engineering
applications, in particular to repair urethral strictures or defects. The polymer tested was a graft copolymer
of polylactic acid (PLA) synthesized with the rationale to improve the toughness of the related PLA
homopolymer. The LMP-3055 graft copolymer (in bulk) demonstrated to have negligible cytotoxicity (bioavailability
N85%, MTT test). Moreover, the LMP-3055 sterilized through gamma rays resulted to be cytocompatible
and non-toxic, and it has a positive effect on cell biofunctionality, promoting the cell growth. 3D scaffolds and
2D film were prepared using different LMP-3055 polymer concentrations (7.5, 10, 12.5 and 15%, w/v), and the
effect of polymer concentration on pore size, porosity and interconnectivity of the 3D scaffolds and 2D film
was investigated. 3D scaffolds got better results for fulfilling structural and biofunctional requirements: porosity,
pore size and interconnectivity, cell attachment and proliferation. 3D scaffolds obtained with 10 and 12.5% polymer
solutions (3D-2 and 3D-3, respectively)were identified as themost suitable construct for the cell attachment
and proliferation presenting pore size ranged between 100 and 400 μm, high porosity (77–78%) and well
interconnected pores. In vitro cell studies demonstrated that all the selected scaffolds were able to support the
cell proliferation, the cell attachment and growth resulting to their dependency on the polymer concentration
and structural features. The degradation test revealed that the degradation of polymer matrix (ΔMw) and
water uptake of 3D scaffolds exceed those of 2D film and raw polymer (used as control reference), while the
mass loss of samples (3D scaffold and 2D film) resulted to be controlled, they showed good stability and
capacity to maintain the physical integrity during the incubation time.