A porcine ex vivo angiogenesis model for retinal neovascular diseases

Retinal and choroidal vascular diseases are the leading causes of vision loss, with diabetic retinopathy and neovascular age-related macular degeneration as prominent examples. Current treatments such as laser photocoagulation and anti-VEGF injections have limitations and side effects. Therefore, there is a need for novel therapies to improve our understanding of underlying disease mechanisms. Animal welfare regulations also mandate a reduction in the use of animals. This study aimed to develop an ex vivo angiogenesis model using porcine retinal explants to study retinal neovascular diseases without using living animals. Porcine retina shares similarities with the human retina, making it a suitable model for studying retinal diseases. Porcine retinas were obtained from a local abattoir and retinal explants were cultured with pro-angiogenic factors to induce neovascularization. Vessel formation was observed using bright-field microscopy and the presence of endothelial cells was confirmed by CD31 immunostaining. qRT-PCR analysis revealed increased expression of angiogenesis-related genes in the treated explants compared to that in the controls. However, this model has limitations such as a lack of blood flow and limited cultivation time. Strategies to address these challenges include optimizing the tissue extraction time, exploring alternative coating materials, and maintaining the retinal tissue-retinal pigment epithelium interface. Nevertheless, this ex vivo porcine retinal angiogenesis model provides a valuable tool for investigating innovative treatment approaches for retinal neovascular diseases while reducing the use of living animals in research.