Angiopoietin-1 and Tie2-Based Dual Cell Therapy Enhances Antiangiogenic Barrier Function in a Retina-Mimetic Model for Neovascular Retinal Disease.

BACKGROUND: Choroidal neovascularization (CNV) is a major pathological process underlying retinal degenerative diseases such as wet age-related macular degeneration. While anti-VEGF therapies are widely used, limitations in response and vascular instability necessitate new approaches that promote both antiangiogenic effects and barrier restoration. METHODS: A dual-cell therapy strategy was developed using human umbilical vein endothelial cells (HUVECs) genetically modified to overexpress Tie2 and mesenchymal stem cells (MSCs) engineered to secrete Angiopoietin-1 (Ang1). Antiangiogenic efficacy was evaluated using scratch assays, Transwell migration, and tube formation under VEGF stimulation. A retina-mimetic 2.5D co-culture system incorporating iPSC-derived RPE cells and mCherry-labeled ECs was used to assess endothelial invasion and epithelial barrier preservation. RESULTS: Tie2/Ang1-modified cells significantly suppressed angiogenic behavior. Transwell migration showed OD595 crystal violet absorbance decreased from 3.54 ± 0.27 (control HUVEC) to 1.28 ± 0.08 (Tie2 overexpressed HUVEC in MSC Ang1 conditioned medium) under VEGF stimulation (p < 0.01). Tube formation area cultured in VEGF dropped from 1.25 ± 0.05 in control group to 0.74 ± 0.07 in Tie2 overexpressed group cultured with MSC-Ang1 conditioned medium (p < 0.01). In the retina-mimetic model, EC infiltration to the RPE monolayer across Transwell membrane decreased from 52.2 ± 8.5% in control HUVEC to 5.6 ± 4.3% with HUVEC-Tie2 + Ang1 conditioned medium under VEGF (p < 0.001). CONCLUSION: This study demonstrates that co-delivery of Ang1 and Tie2 via engineered ECs and MSCs synergistically inhibits VEGF-induced angiogenesis and choroidal migration while protecting epithelial barrier function. The retina-mimetic co-culture platform further validates the translational relevance of this dual-cell approach as a regenerative and antiangiogenic strategy in retinal vascular disease.