Physiomimetic Models of Adenomyosis

Abstract

Adenomyosis remains an enigmatic disease in the clinical and research communities. The high prevalence, diversity of morphological and symptomatic presentations, array of potential etiological explanations, and variable response to existing interventions suggest that different subgroups of patients with distinguishable mechanistic drivers of disease may exist. These factors, combined with the weak links to genetic predisposition, make the entire spectrum of the human condition challenging to model in animals. Here, after an overview of current approaches, a vision for applying physiomimetic modeling to adenomyosis is presented. Physiomimetics combines a system's biology analysis of patient populations to generate hypotheses about mechanistic bases for stratification with in vitro patient avatars to test these hypotheses. A substantial foundation for three-dimensional (3D) tissue engineering of adenomyosis lesions exists in several disparate areas: epithelial organoid technology; synthetic biomaterials matrices for epithelial-stromal coculture; smooth muscle 3D tissue engineering; and microvascular tissue engineering. These approaches can potentially be combined with microfluidic platform technologies to model the lesion microenvironment and can potentially be coupled to other microorgan systems to examine systemic effects. In vitro patient-derived models are constructed to answer specific questions leading to target identification and validation in a manner that informs preclinical research and ultimately clinical trial design.

Fig. 1 Physiomimetic approach for developing targeted therapies for adenomyosis

. Hypotheses regarding different mechanisms of disease that may be operative in patient subgroups are tested with tissue and fluid samples from a large patient population containing the subgroups (1); analysis of tissue and fluid samples to refine hypotheses about mechanism (2a and 3) are performed in tandem with development of cell banks and construction of patient avatars (2b). Mechanistic hypothesis about patient subgroups and interventions can then be tested in patient avatars representing the subgroups to define stratified clinical trials, or inform more judicious use of existing therapies.

Fig. 2

Conceptualization of an adenomyosis lesion, showing the biological components and pathological processes to consider in building an in vitro model.

Fig. 3 Development of 3D in vitro models using synthetic hydrogels and endometrial epithelial organoids technologies

. ( a ) Endometrial epithelial organoids (EEOs) promote the culture, expansion, and propagation of epithelial cells using 3D hydrogel systems. EEOs retain epithelial structure, heterogeneity, and function of the native tissue glands. ( b ) Bio-labile, synthetic extracellular matrices (ECMs) can be designed to establish EEOs cultures and cocultures that include additional cell populations, such as endometrial stromal cells (ESCs). ( c ) Polyethylene glycol (PEG)-derived hydrogels are fully defined, modular, and can be tuned by modifying their molecular and biophysical properties to mimic key features of the adenomyotic and endometriotic phenotype.

Fig. 4 Microfluidic model of immune and tumor cell trafficking between the microvasculature and tissues

. ( a ) A microfluidic device comprising a central tissue-containing channel, flanked by two channels for flow of culture medium, is inoculated with a mixture of fibrin containing endothelial and stromal cells. Over the initial few days, cells undergo morphogenesis to form perfusable microvascular networks which are stable for weeks in culture as shown in ( b ) for a day 23 culture (actin stain). ( c ) Immune cells (green) can be perfused through the microvasculature (red) to model peripheral cell recruitment. ( d ) The dynamic cell-level phenomena in the devices can be imagined by confocal or two-photon microscopy to observe phenomena such as neutrophil–tumor cell interactions in the extravasation of tumor cells through the vascular wall into tissue. (Images from Zhang et al, permission is in progress.)