3D Printing and Electrospinning of PLLA-co-CL/PDLA Blends as Potential Materials for Cardiovascular Implants

Cardiovascular implants are limited by the lack of materials that combine mechanical strength with bioactivity to support endothelial function, prevent thrombosis, and promote long-term integration. Conventional polymers often lack these biological features, underscoring the need for multifunctional biomaterials. This study evaluates poly[(l-lactide)-co-(ε-caprolactone)]/poly(d-lactide) (PLLA-co-CL/PDLA) blends processed via 3D printing and electrospinning and assesses their suitability as cardiovascular implant coverings through material characterization and endothelial cell interactions. Blend compositions were fabricated as films and meshes, and optimized constructs were selected for cytocompatibility and endothelial biofunctionality testing. Endothelial responses were evaluated over 7 days through viability assays and quantification of vasoactive mediators, including Thromboxane B₂ (TXB₂), Prostacyclin (PGI₂), and Nitric Oxide (NO). Among all formulations, the 90:10 PLLA-co-CL/PDLA blend exhibited the most favorable wettability (76.5° ± 4.0), indicating enhanced hydrophilicity at intermediate compositions. Electrospun meshes supported high HUVEC viability (>80%) and metabolic activity, while 90:10 films maintained ∼67% viability after 7 days. Functional analysis showed increasing PGI₂ release over time, reaching ∼966 pg/mL on 90:10 films, whereas TXB₂ rose moderately. The PGI₂/TXB₂ ratio shifted from pro-thrombotic (<1) on day 1 to antithrombotic (>1) by day 7, indicating endothelial stabilization. NO release increased to ∼0.82 μmol/L on films and ∼0.9 μmol/L on meshes, reflecting improved endothelial function and vascular homeostasis. Hemolytic potential was assessed via red blood cell lysis assays. All films and meshes exhibited negligible hemolysis (0.027-0.660%), comparable to a silicone elastomer reference (0.153%) and substantially lower than slightly hemolytic controls (Buna-N, 3.177%), indicating minimal erythrocyte membrane disruption. Overall, PLLA-co-CL/PDLA blends─particularly 3D-printed films at a 90:10 ratio─provide hydrophilic, cyto-compatible surfaces that support endothelial viability and balanced vasoactive signaling. These findings highlight their potential as biodegradable cardiovascular implant coverings.