Engineering Biophysical Microenvironments to Regulate In vitro Organogenesis and Morphogenesis
Engineering biophysical microenvironments to regulate organogenesis and morphogenesis in vitro is essential for advancing tissue engineering and regenerative medicine. This study presents two innovative approaches for creating and utilizing such microenvironments to achieve enhanced control over organ and tissue development.
Firstly, we present UniMat, a novel organoid culture platform designed to optimize the microenvironment for enhanced organogenesis of organoids. UniMat features a 3D geometrically engineered, permeable nanofibrous membrane that ensures the consistent delivery of essential soluble factors while supporting uniform organoid development. By precisely regulating chemical microenvironments such as nutrient gradients and differentiation signals, UniMat promotes organogenesis with improved structural and functional attributes. For example, human-induced pluripotent stem cell (iPSC)-derived kidney organoids cultured using UniMat exhibit increased nephron transcript expression, an in vivo-like cell-type balance, and enhanced vascularization. This advancement in organoid culture techniques enables more accurate modeling of organogenesis compared to traditional methods.
Secondly, we introduce a tissue-scale in vitro epithelial bilayer folding model that replicates the complex folding morphogenesis observed in vivo. This model integrates an epithelium with an extracellular matrix (ECM) hydrogel in a precisely engineered system. The epithelium is cultured on a substrate that mimics the mechanical microenvironment of native tissues, while the ECM hydrogel provides a supportive matrix with controlled poroelasticity. By adjusting parameters such as substrate stiffness and hydrogel composition, we induce a spectrum of folding behaviors, ranging from periodic wrinkles to deep folds, under applied compression. A custom-designed compression system applies uniform mechanical forces to the bilayer structure, allowing for real-time observation of folding dynamics. Experimental data, supported by theoretical modeling, reveal that the strain-stiffening response of the epithelium and the poroelasticity of the ECM are critical factors in shaping these folded structures. This model provides valuable insights into epithelial morphogenesis and serves as a powerful tool for exploring the biophysical cues driving tissue development.
Together, these innovative approaches to engineering biophysical microenvironments represent transformative systems for studying and regulating organogenesis and morphogenesis in vitro. Their applications hold significant promise for advancing developmental biology, regenerative therapies, and drug testing.
Keywords
Organoid, Epithelial bilayer folding, 3D Nanofibrous membrane, ECM hydrogel
