A starch propionate–triacetin system for flexible biological tissue preservation – A pilot study in chicken hearts

Background Conventional plastination produces durable anatomical specimens but often depends on specialized infrastructure, synthetic curable polymers, and processing conditions that may limit accessibility. Plastinated specimens may also lack sufficient flexibility for repeated handling, dissection, and teaching demonstrations. Objective This pilot study investigated a bio-based starch propionate–triacetin system as an equipment-minimal approach for producing flexible preserved biological specimens. Methods Corn starch was esterified with propionic anhydride to produce starch propionate with a degree of substitution of 0.14. Successful modification was confirmed by FTIR and 1 H NMR through characteristic propionyl signals. Thirty-two chicken hearts were fixed, dehydrated, degreased, and passively diffused in DMSO solutions containing 0%, 1%, 2.5%, 5%, 7.5%, or 10% starch propionate. Specimens were then plasticized through stepwise solvent exchange with increasing triacetin concentrations and dried under ambient conditions. Results Successfully processed specimens became dry, odorless, handleable, and retained their gross anatomical structure. Dehydration accounted for the major volume reduction, while subsequent starch propionate–triacetin treatment caused only limited additional shrinkage in most groups. The negative control showed the greatest mass loss and lowest flexibility. Starch propionate-treated specimens demonstrated improved flexibility, particularly at higher concentrations. The 7.5% and 10% groups better preserved delicate structures such as major arteries, while the 7.5% formulation provided the most balanced outcome in terms of shape retention, flexibility, and coloration. Conclusion Starch propionate combined with triacetin may provide a simple, bio-derived, and equipment-minimal method for producing flexible, dissectible specimens for hands-on anatomical education. Further studies should optimize formulation parameters, assess long-term stability, and validate the method using larger and more complex specimens.