Evaluation of polycaprolactone − poly-D,L-lactide copolymer as biomaterial for breast tissue engineering

The potential of the copolymer polycaprolactone-co-poly-d,l-lactic acid (PCLLA) as a biomaterial for scaffold-based therapy for breast tissue engineering applications was assessed. First, the synthesized PCLLA was evaluated for its processability by means of additive manufacturing (AM). We found that the synthesized PCLLA could be fabricated into scaffolds with an overall gross morphology and porosity similar to that of polycaprolactone. The PCLLA scaffolds possessed a compressive Young's modulus (ca 46 kPa) similar to that of native breast (0.5 − 25 kPa), but lacked thermal stability and underwent thermal degradation during the fabrication process. The PCLLA scaffolds underwent rapid degradation in vitro which was characterized by loss of the scaffolds' mechanical integrity and a drastic decrease in mass-average molar mass (M_w) and number-average molar mass (M_n) after 4 weeks of immersion in phosphate buffer solution maintained at 37 °C. The tin-catalysed PCLLA scaffold was also found to have cytotoxic effects on cells. Although the initial mechanical properties of the PCLLA scaffolds generally showed potential for applications in breast tissue regeneration, the thermal stability of the copolymer for AM processes, biocompatibility towards cells and degradation rate is not satisfactory at this stage. Therefore, we conclude that research efforts should be geared towards fine-tuning the copolymer synthesizing methods.