Magnetic bioassembly platforms for establishing craniofacial exocrine gland organoids as aging in vitro models

Abstract

A multitude of aging-related factors and systemic conditions can cause lacrimal gland (LG) or salivary gland (SG) hypofunction leading to degenerative dry eye disease (DED) or dry mouth syndrome, respectively. Currently, there are no effective regenerative therapies that can fully reverse such gland hypofunction due to the lack of reproducible in vitro aging models or organoids required to develop novel treatments for multi-omic profiling. Previously, our research group successful developed three-dimensional (3D) bioassembly nanotechnologies towards the generation of functional exocrine gland organoids via magnetic 3D bioprinting platforms (M3DB). To meet the needs of our aging Asian societies, a next step was taken to design consistent M3DB protocols to engineer LG and SG organoid models with aging molecular and pathological features. Herein, a feasible step-by-step protocol was provided for producing both LG and SG organoids using M3DB platforms. Such protocol provided reproducible outcomes with final organoid products resembling LG or SG native parenchymal epithelial tissues. Both acinar and ductal epithelial compartments were prominent (21 ± 4.32% versus 42 ± 6.72%, respectively), and could be clearly identified in these organoids. Meanwhile, these can be further developed into aging signature models by inducing cellular senescence via chemical mutagenesis. The generation of senescence-like organoids will be our ultimate milestone aiming towards high throughput applications for drug screening and discovery, and for gene therapy investigations to reverse aging.

Bioprinting salivary gland models and their regenerative applications

“…A recent study utilized porcine primary SG and lacrimal grand (LG) cells on the M3DB platform to create functional craniofacial exocrine gland organoids for in vitro aging models. These organoids expressed functional acinar and ductal units with epithelial progenitors, and successfully induced cellular senescence to mimic the native SG and LG hypofunction representing dry eyes and dry mouth [74]. Notably, the transplantation of organoids rescued both the epithelial bud and neuronal components of ex vivo irradiated SG.…”

Bioengineered Salivary Gland Microtissues─A Review of 3D Cellular Models and their Applications

“…When cultured in 3D modular hyaluronate hydrogels modified with basement membrane-derived peptides, the SGSCs exhibited enhanced viability, stemness, and expression of progenitor markers . Other efforts to replace animal-based 3D matrices for culturing and expanding SGSCs include the use of magnetic bio assembly − or microwell-based , platforms to isolate and culture SGSCs and are discussed in the next section.…”