Scientists develop ‘pseudo cell’ formulation for vitreoretinal disease therapy

Vitreoretinal diseases include a wide spectrum of vision-threatening disorders, such as age-related macular degeneration (AMD), diabetic retinopathy and retinal detachment, which may cause severe irreversible vision loss. The efficacy of current treatments for vitreoretinal diseases in clinic is generally unsatisfactory and treatments often cause several side effects. Moreover, frequently repeated treatments are often needed, leading to poor patient compliance. 

In recent years, researchers have explored the possibility of cell-based therapy in ophthalmology. Despite some positive results, cell-based therapeutics in ophthalmology have encountered a series of problems, such as low cell-survival rates and the need for strict storage conditions, which have limited the clinical feasibility of these cell-based technologies.

The therapeutic benefits of many cell types are known to involve paracrine mechanisms, a type of cellular communication in which a cell produces a signal to induce changes in nearby cells, altering the behavior of those cells. Therefore, researchers have explored the possibility of using more stable signal-secreting components as therapeutic components to treat ocular diseases. One possibility being explored is the use of exosomes, membrane bound vesicles that are secreted by cells. 

Inspired by this, researchers from the Institute of Process Engineering (IPE) of the Chinese Academy of Sciences and Beijing Chaoyang Hospital have proposed a “pseudo cell” formulation platform. In this platform, exosomes isolated from cells were loaded into self-healing microcapsules, called ExoCaps. “ExoCaps simulate functional cells in terms of size, internal structure, and secretion behavior,” said Prof. Ma Guanghui from IPE. After injection into the eye, exosomes were gradually released as the microcapsules degraded over a month, paving the way for a long-term therapeutic effect.

The researchers saw potent therapeutic benefits of two different ExoCap formulations in both mouse and non-human primate models of vitreoretinal diseases. While the results were promising, the authors caution that this research is still at the preclinical stage. Nonetheless, the researchers are hopeful that the new ExoCaps will someday translate into the clinic. 

Sources:

Medical Xpress, October 23, 2023; see  source article Bao et al, Nature Biomedical Engineering (2023). DOI: 10.1038/s41551-023-01112-3