Session: 07-04-01: Biomaterials and Tissue: Modelling, Fabrication and Characterization

Paper Number: 191626

Structural and Mechanical Characterization of a Biomimetic Intestinal Villus-Crypt Scaffold Fabricated via Vat Photopolymerization 

Current in vitro intestinal models lack the mechanical compliance and architectural complexity required to replicate the dynamic gastrointestinal (GI) microenvironment accurately. Traditional two-dimensional (2D) monolayer cultures and rigid three-dimensional (3D) scaffolds fail to reproduce the coupled effects of curvature, elasticity, and cyclic peristaltic deformation that govern epithelial organization, mechanotransduction, and transport behavior. Hierarchical villus-crypt structures characterize the native intestine and undergo continuous rhythmic mechanical loading, which directly influences cell differentiation, barrier integrity, and nutrient absorption. Replicating these biomechanical cues in engineered platforms remains a critical challenge in tissue-inspired system design. This work addresses this gap through the mechanical design, high-resolution stereolithographic additive manufacturing, and multiphysics evaluation of a compliant 3D-printed intestinal scaffold engineered to emulate physiologically relevant geometry and deformation behavior.

Scaffold architectures were developed using parametric computer-aided design (CAD) modeling to systematically control villi-inspired projections, microgroove alignment, curvature gradients, and internal porosity. The design framework enables independent tuning of geometric parameters such as villus height, diameter, spacing, and base thickness, allowing investigation of structure–mechanics relationships while preserving global structural integrity under cyclic strain. Finite deformation considerations were incorporated to ensure that the scaffold could sustain repeated tensile loading without buckling, delamination, or stress localization at the villus base.

High-resolution stereolithography (SLA) printing was performed using a Formlabs Form 4B platform to fabricate villus-scale microfeatures with micron-level precision and smooth surface finish. Photopolymerizable elastomeric and biocompatible resin systems were selected to achieve tunable elastic moduli within the range reported for native intestinal tissue. Process parameters, including exposure time, layer thickness, laser power, and post-curing conditions, were optimized to control polymer crosslinking density, dimensional accuracy, and surface topography. This ensured reproducible microarchitecture and consistent mechanical response across multiple fabrication cycles.

Morphological characterization was conducted using confocal microscopy and scanning electron microscopy (SEM) to evaluate feature fidelity, surface roughness, and geometric stability of the villus-like projections. Mechanical characterization included nanoindentation to measure local Young’s modulus and interfacial adhesion, as well as microhardness testing to quantify Vickers hardness and resistance to localized deformation. The relationship between scaffold geometry and mechanical response was systematically examined to establish geometry-property correlations, particularly under simulated cyclic loading conditions representative of peristaltic motion.

The resulting platform demonstrates how high-resolution vat photopolymerization can be leveraged to engineer compliant, microarchitectured systems with controlled deformation profiles and predictable mechanical behavior. By integrating parametric design, material optimization, and quantitative structural testing, this study provides a scalable framework for mechanically active biomimetic platforms. The work advances the application of additive manufacturing in soft-tissue-inspired engineering systems and establishes foundational principles for developing next-generation in vitro intestinal models that replicate physiologically relevant mechanical stimuli.

Presenting Author: Benjamin Anderson University of Arkansas at Little Rock

Presenting Author Biography: Ben Anderson is a Senior in the Mechanical Engineering Program at the University of Arkansas at Little Rock. He is the president of the ASME student chapter at UA Little Rock. He is passionate about additive manufacturing and materials science.

Authors:

Shrigun Maroo University of Arkansas at Little Rock
Benjamin Anderson University of Arkansas at Little Rock
William Heap University of Arkansas at Little Rock
Rupak Pathak University of Arkansas Medical Sciences
Sujan Ghosh University of Arkansas at Little Rock