A common event in optic neuropathies
is the loss of axons and death
of retinal ganglion cells (RGCs) resulting in irreversible blindness.
Mammalian target of rapamycin (mTOR) signaling pathway agonists have
been shown to foster axon regeneration and RGC survival in animal
models of optic nerve damage. However, many challenges remain in developing
therapies that exploit cell growth and tissue remodeling including
(i) activating/inhibiting cell pathways synergistically, (ii) avoiding
tumorigenesis, and (iii) ensuring appropriate physiological tissue
function. These challenges are further exacerbated by the need to
overcome ocular physiological barriers and clearance mechanisms. Here
we present liposomes loaded with multiple mTOR pathway stimulating
biologics designed to enhance neuroprotection after retina damage.
Liposomes were loaded with ciliary neurotrophic factor, insulin-like
growth factor 1, a lipopeptide N-fragment osteopontin mimic, and lipopeptide
phosphatase tension homologue inhibitors for either the ATP domain
or the c-terminal tail. In a mouse model of N-methyl-d-aspartic acid induced RGC death, a single intravitreal administration
of liposomes reduced both RGC death and loss of retina electrophysiological
function. Furthermore, combining liposomes with transplantation of
induced pluripotent stem cell derived RGCs led to an improved electrophysiological
outcome in mice. The results presented here show that liposomes carrying
multiple signaling pathway modulators can facilitate neuroprotection
and transplant electrophysiological outcome.