Construction of Dome-Shaped 3D Corneal Epithelial Tissue Models Based on Eyeball-Shaped Gel Microspheres.

By overcoming interspecies differences and mimicking the in vivo microenvironment, three-dimensional (3D) in vitro corneal models have become a significant novel tool in contemporary ophthalmic disease research. However, existing 3D corneal models struggle to replicate the actual human corneal environment, especially the dome-shaped physiological structure with adjustable curvature. Addressing these challenges, this study introduces a straightforward method for fabricating collagen/chitosan-alginate eyeball-shaped gel microspheres with a Janus structure via a two-phase aqueous system, used subsequently to construct in vitro 3D corneal epithelial tissue models. By adjusting the diameter ratio of collagen/chitosan to alginate droplets, we can create eyeball-shaped gel microspheres with varying curvatures. Human corneal epithelial cells were seeded on the surfaces of these microspheres, leading to the formation of in vitro 3D corneal epithelial tissues characterized by dome-like multilayers and tight junctions. Additionally, the model demonstrated responsiveness to UVB exposure through the secretion of reactive oxygen species (ROS) and proinflammatory factors. Therefore, we believe that in vitro 3D corneal epithelial tissue models with dome-shaped structures hold significant potential for advancing ophthalmic research.

All-aqueous droplets-templated tailorable core-shell alginate microspheres for constructing vascularized intestinal mucosain vitromodels.

Recently,in vitromodels of intestinal mucosa have become important tools for drug screening and studying the physiology and pathology of the intestine. These models enable the examination of cellular behavior in diseased states or in reaction to alterations in the microenvironment, potentially serving as alternatives to animal models. One of the major challenges in constructing physiologically relevantin vitromodels of intestinal mucosa is the creation of three-dimensional microstructures that accurately mimic the integration of intestinal epithelium and vascularized stroma. Here, core-shell alginate (Alg) microspheres were generated to create the compartmentalized extracellular matrix microenvironment needed to simulate the epithelial and vascularized stromal compartments of the intestinal mucosa. We demonstrated that NIH-3T3 and human umbilical vein endothelial cells embedded in the core of the microspheres can proliferate and develop a vascular network, while human colorectal adenocarcinoma cells (Caco-2) can form an epithelial monolayer in the shell. Compared to Caco-2 monolayer encapsulated within the shell, the presence of the vascularized stroma enhances their proliferation and functionality. As such, our core-shell Alg microspheres provide a valuable method for generatingin vitromodels of vascularized intestinal mucosa with epithelial and vascularized stroma arranged in a spatially relevant manner and demonstrating near-physiological functionality.

Microfluidic aqueous two-phase system-based nitrifying bacteria encapsulated colloidosomes for green and sustainable ammonium-nitrogen wastewater treatment.

A novel strategy was proposed for preparing micro-scale monodisperses nitrifying bacteria (NB) encapsulated Ca-Alg@CaCO3 colloidosomes by exploiting capillary microfluidic device, as an attempt to treat ammonium-nitrogen wastewater in an environment-friendly, efficient and repeatable manner based on the aqueous two-phase (ATPS) system. By complying with the spatial confined urease mediate biomineralization reactions, ATPS droplets (Dextran in Polyethylene glycol) containing urease, NB regent and alginate were used as templates to prepare 500 µm Ca-Alg@CaCO3 colloidosomes with 16.48 Mpa mechanical strength. The activity of NB encapsulated in the colloidosomes was high. The simulated wastewater treated with the colloidosomes achieved a high removal rate even at harsh temperature and pH value. In both simulated and real wastewater treatment, prolonged reuse times (216 h) with high removal rate (＞90%, after being applied 72 h) were obtained by using Ca-Alg@CaCO3 colloidosomes, as compared with that (96 h) by using general alginate microbeads.