# Characterization of Hydrolytic and Thermomechanical Stability of 3D-Printed PLDLA-TMC 60/40 Scaffolds for Cartilage Tissue Applications

## TL;DR

This study examines how 3D-printed PLDLA-TMC scaffolds degrade and support cartilage growth under simulated body conditions.

## Contribution

The study provides new insights into the thermomechanical and hydrolytic stability of 3D-printed PLDLA-TMC scaffolds for cartilage tissue engineering.

## Key findings

- Printing at 120 °C preserved polymer integrity better than higher temperatures.
- Dynamic perfusion culture enhanced chondrogenesis and cell infiltration.
- Dynamic conditions produced a more organized hyaline-like matrix compared to static culture.

## Abstract

Biodegradable thermoplastic
polymers are increasingly explored
in regenerative medicine due to their potential to mimic native tissue
environments. Among them, poly­(L-co-D,L-lactic acid-co-trimethylene carbonate) (PLDLA-TMC) offers tunable degradation
and biocompatibility features. However, extrusion-based 3D printing
may induce polymer chain scission, compromising scaffold integrity
under physiological conditions. Although PLDLA-TMC has been explored
in various biomedical applications, there is a lack of studies assessing
its performance under mechanically stimulated environments that emulate in vivo conditions, which limits its translation to load-bearing
tissues such as cartilage. To address this gap, this study investigates
the hydrolytic and thermomechanical degradation of 3D-printed PLDLA-TMC
60/40 scaffolds and their biological behavior under dynamic perfusion
culture. Temperature-dependent degradation was confirmed, as printing
at 120 °C preserved polymer integrity more efficiently, while
both M
n and M
w decreased by approximately 50% after 2 weeks of hydrolytic degradation
and by 80% after 4 weeks (p < 0.01). Dynamic culture
assays demonstrated enhanced chondrogenesis, with type II collagen
and SOX9 showing approximately 2-fold higher fluorescence intensities.
Although aggrecan displayed slightly higher total labeling under static
culture, dynamic perfusion reduced the fluorescence peak width by
40%, supporting a more stratified hyaline-like matrix. Perfusion also
promoted significantly greater cell infiltration (p < 0.05). Altogether, these results highlight the suitability
of PLDLA-TMC scaffolds for mechanically stimulated tissue-engineering
applications, particularly cartilage regeneration.