A Bioprinted Bruch's Membrane for Modeling Smoke‐Induced Retinal Pigment Epithelium Degeneration via Hybrid Membrane Printing Technology

Abstract

The retinal pigment epithelium (RPE) not only forms the outer blood-retinal barrier (oBRB) but also plays a multifunctional role in the ocular system. The loss of this epithelium leads to serious diseases resulting in vision impairment. No effective treatment is available for the repair of RPE damage. A functional in vitro RPE model that allows the recapitulation of oBRB-related pathophysiological responses is lacking. Here, a hybrid membrane printing technology is developed to fabricate cellular monolayers on the basement membrane to mimic human Bruch's membrane (BM). Using this technology, in vitro oBRB model containing the RPE monolayer on the printed BM with stable mechanical properties and fibril diameter similar to that of natural BM is developed. Compared to traditional collagen bioink, BM-based bioink significantly promotes RPE functions in vitro. Finally, smoking-like conditions are exposed to the model to recapitulate the absorption of mainstream cigarette smoke which is known as one of the risk factors for the disease progression. RPE function is damaged due to oxidative stress. Furthermore, the versatility of the model as a drug-testing platform is confirmed by the suppression of oxidative stress via antioxidants. This technology shows potential for fabricating a functional oBRB model that reflects patient conditions.

Organoid bioinks: construction and application

“…Subsequently, they utilized a 3% gelatin bioink to bioprint retinal pigment epithelial cells on the top layer, producing a single-cell layer. In vitro experiments have demonstrated that this organoid bioink-printed blood-retinal barrier model displays functions related to barrier clearance, vision, and maintenance [137] (figures 12(A)-(C)). In another study, Kapil Bharti successfully utilized bioprinting to create a natural, three-dimensional oBRB tissue.…”

Towards Precision Ophthalmology: The Role of 3D Printing and Bioprinting in Oculoplastic Surgery, Retinal, Corneal, and Glaucoma Treatment

“…Three-dimensional bioprinted retinal tissue models can also be used to study external environmental factors on ocular health. Kim et al found that oxidative stress induced by cigarette smoke can disrupt RPE tight junction strength and blood–retinal barrier function [ 66 ]. This information can be used to further explore causative links between smoking and retinal degeneration.…”

Fabrication Strategies for Engineered Thin Membranous Tissues

“…In vivo , transparency of the R5-CEC membranes was better maintained than acellular membranes, demonstrating that cell engineering and 3DP delivery of CECs led to better cell survival and function. Similarly, another group used 3DP to generate a multilayered structure consisting of a vitrified decellularized Bruch’s membrane (BM) layer with retinal pigment epithelial (RPE) cells encapsulated in a sacrificial gelatin layer on top . This structure functioned as a model of the outer blood–retinal barrier to assess the disease conditions on RPE cell function.…”

“…Similarly, another group used 3DP to generate a multilayered structure consisting of a vitrified decellularized Bruch's membrane (BM) layer with retinal pigment epithelial (RPE) cells encapsulated in a sacrificial gelatin layer on top. 110 This structure functioned as a model of the outer blood−retinal barrier to assess the disease conditions on RPE cell function. Bioprinting allowed functional monolayer formation of RPE cells on the basement membrane to accurately replicate native anatomy, and the effects of cigarette smoke extract on cell function were evaluated.…”