Rapid method to screen biomaterial angiogenesis in vivo using fluorescence imaging in mice†

Effective vascularization is crucial for repairing and enhancing the longevity of engineered tissues and organs. As the field advances, there is a vital need for efficient and reliable methods for assessing vascularization in real-time. The integration and performance of constructed biomaterials in living organisms rely on angiogenesis and vascularization, making it essential to evaluate vascular development and networks within biomaterials. Current histology-based methods are limited and labor-intensive. On the other hand, fluorescence imaging offers promise for efficient, real-time evaluation of angiogenesis, reducing the time needed for screening many compounds and offering a high-throughput alternative to histology-based methods. Here, we investigated a novel, non-invasive method for quick and repeated analysis of the angiogenic and vascularization process in biomaterials via fluorescence IVIS imaging. Multi-domain peptides (MDPs), self-assembling peptide hydrogels that can possess pro-angiogenic properties depending on their primary sequence, were synthesized and utilized as angiogenic biomaterials and screened with a fluorescence IVIS probe to demonstrate real-time rapid angiogenesis in vivo. The fluorescence-based imaging showed the influence of the peptide chemistry, volume, and concentration on angiogenesis, with one particular MDP, SLanc, promoting robust angiogenesis after one week at 2 w/v%. Through this method, we were able to identify the optimal peptide for rapid and sustained angiogenesis. This approach enables real-time monitoring of angiogenic responses and vascularization processes in the same living subject. It promotes the development of new biomaterials that facilitate vascularization and validates an advanced in vivo screening technique for angiogenesis.