Developing models to predict mechanical behavior of PCL/PHBV composites for tissue Engineering: A response surface methodology study.

Abstract

A combination of Poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and Polycaprolactone (PCL) has always been recommended for bone tissue engineering; however, different polymer ratios and porosities exhibit distinct physicochemical and mechanical properties. Since bone tissues vary in mechanical demands, a reliable predictive model can guide scaffold design before laboratory fabrication, reducing both cost and time for researchers. This study proposes numerical models using Response Surface Methodology (RSM) alongside an experimental study to evaluate PHBV/PCL blends with varying porosities. In this study, 13 PHBV/PCL scaffolds with varying porosities were fabricated and analyzed. Experimental results showed that the properties of PHBV/PCL scaffolds were strongly influenced by polymer ratio and porosity. Pure PCL (20 %) exhibited higher porosity (>20 %) compared to pure PHBV (<8 %). In PCL-based groups, increasing NaCl content (porosity) elevated the contact angle from 74° to 115°, while water uptake rose from <10 % (no NaCl) to ∼200 %, highlighting PCL's role in enhancing hydrophilicity. More porous samples also showed slower water removal (174 %-1 % over 48 h). Mechanical testing revealed elastic modulus values ranging from 34 to 931 MPa and 6-287 MPa for wet and dried scaffolds, respectively. Importantly, Response Surface Methodology (RSM) demonstrated excellent predictive accuracy (R² = 0.93-0.99), confirming its utility as a robust numerical tool for estimating scaffold properties. These findings highlight RSM's potential to accelerate scaffold optimization and support researchers in tailoring PHBV/PCL blends for diverse bone tissue requirements.