Sustainable fabrication of biodegradable polycaprolactone/ZnO electrospun scaffolds: centroid-mediated solvent...

Advances in polymer technology have provided humankind with a plethora of polymers for use in various sectors, such as tissue engineering, packaging, and personal care and hygiene products. However, the disposal of spent plastics imposes a serious environmental burden and has resulted in biodegradability being considered an essential criterion for single-use polymeric films. Herein, a non-solvent-induced phase separation (NIPS)-based electrospinning method was adopted for the synthesis of biodegradable, porous polycaprolactone-zinc oxide (ZnO) composite nonwoven films. Structural analysis confirmed the uniform incorporation of ZnO nanoparticles without altering PCL chemistry. The selection of solvent mixture ratios was performed using Hansen solubility parameters and by calculating the resulting centroidal distance. This novel centroidal framework enables the selection of appropriate solvent mixtures with balanced affinity toward the polymer and the nanofiller. Chloroform, dimethyl sulfoxide (DMSO), and acetone were used as unary and binary solvent systems. The effects of the Hansen parameters and centroidal distances on the biodegradation properties of the electrospun films were established. Among the three solvents, DMSO exhibits the lowest volatility and the highest conductivity and dielectric constant, whereas chloroform has high volatility, a low dielectric constant, and low conductivity. When combined as a solvent mixture for PCL-ZnO and electrospun, this resulted in fibers with numerous inherent pores, indicating significant phase separation. The film exhibited appreciable degradability when exposed to environmental conditions. A low centroidal distance of the solvent mixture correlated with enhanced porous structures, increased accessibility to hydrolytic and microbial degradation, and a reduced chemical footprint. This predictive methodology thus minimizes experimental iterations and solvent waste, leading to a sustainable route for designing electrospun scaffolds with enhanced environmental degradability.