Fabrication, characterization, and in vivo biosafety evaluation of starch-based bioplastic as a sustainable alternative to polystyrene

The widespread use of synthetic plastics such as polystyrene raises concerns over long-term environmental persistence and biological toxicity. Although bioplastics offer a promising alternative, their in vivo biosafety and comparative evaluation with conventional plastics remain insufficiently explored. The study aimed to develop and characterize a starch-based bioplastic derived from Eriobotrya japonica (loquat) seeds and to evaluate its in vivo biosafety in Swiss albino mice. The novelty of this work lies in utilizing an underreported starch source and performing a direct comparison with polystyrene to establish a biological benchmark. Differential Scanning Calorimetry revealed low enthalpies of fusion (2.55 J/g) and crystallization (9.24 J/g), confirming the predominantly amorphous and thermally soft nature of the film. These characteristics, combined with moderate flexibility and moisture permeability, suggest biological compatibility for in vivo applications. Hematological analysis showed elevated white blood cell counts in the polystyrene group (6.75 ± 0.7 × 10³/cmm) compared to the starch-based bioplastic group (3.7 ± 0.4 × 10³/cmm), which remained within the normal range. Histological examination revealed normal tissue architecture in the liver, kidney, and heart of mice treated with starch-based bioplastic, while polystyrene caused mild hepatocellular degeneration and early myocardial hypertrophy. Overall, the results confirm the biosafety and biocompatibility of the prepared starch-based bioplastic as a sustainable alternative to petroleum-based plastics for environmental and biomedical applications.