A 3D Intestinal Scaffold Supporting In Vitro Morphological Changes in Strongyloides stercoralis Infective Larvae

Strongyloides stercoralis is a soil-transmitted helminth with a complex life cycle, characterized by the ability to establish chronic infections. The intricate interplay between the parasite and the host intestinal environment is therefore central to disease pathogenesis. In this study, we explored a conventional two-dimensional system and a novel in vitro platform with a custom three-dimensional scaffold designed to mimic the intestinal microarchitecture for parasite in vitro maintenance and growth. Using human intestinal epithelial Caco-2 cells and clinical isolates of S. stercoralis infective larvae, we assessed larval viability, morphometric changes, and developmental progression under basal conditions and in response to steroidal stimuli. While both systems supported larval survival, the 3D model also promoted sustained morphological development. Larvae cultured in the 3D environment exhibited the emergence of features indicative of partial developmental progression, along with significant increases in both length and width over time. In contrast, larvae maintained in the 2D system remained viable but showed limited and transient morphometric changes. Exposure to hydrocortisone enhanced larval growth in both systems, although its effects were more consistent and sustained in the 3D model. Overall, our findings suggest that the 3D system provides conditions that support larval survival and morphological changes consistent with partial developmental progression. Although not sufficient to fully support complete development, this platform represents a meaningful step forward toward the development of an in vitro tool for studying S. stercoralis biology and pathobiology.