Enzyme-responsive polymersomes ameliorate autophagic failure in a cellular model of GM1 gangliosidosis

Abstract

GM1 gangliosidosis is a lysosomal storage disorder caused by deficiency of β-galactosidase (βgal) and subsequent accumulation of GM1 ganglioside in lysosomes. One of the pathological aspects of GM1 gangliosidosis, and other storage disorders, is impaired autophagy, i.e., a reduced fusion of autophagosomes and lysosomes to degrade cellular waste. Enzyme replacement therapy (ERT) can effectively treat systemic deficiency but is limited by immunogenicity and shortened half-life of intravenously administered enzyme. In this paper, we report a hyaluronic acid-b-polylactic acid (HA-PLA) polymersome delivery system that can achieve an enzyme-responsive and sustained delivery of βgal to promote the cell’s self-healing process of autophagy. HA-PLA polymersomes have an average diameter of 138.0 ± 17.6 nm and encapsulate βgal with an efficiency of 77.7 ± 3.4%. In the presence of model enzyme Hyaluronidase, HA-PLA polymersomes demonstrate a two-fold higher release of encapsulant than without enzyme. We also identified reduced autophagy in a cellular model of GM1 Gangliosidosis (GM1SV3) compared to healthy cells, illustrated using immunofluorescence. Enhanced autophagy was reported in GM1SV3 cells treated with βgal-loaded polymersomes. Most notably, the fusion of lysosomes and autophagosomes in GM1SV3 cells returned to normal levels of healthy cells after 24 h of polymersome treatment. The HA-PLA polymersomes described here can provide a promising delivery system to treat GM1 Gangliosidosis.

Polymersomes as the Next Attractive Generation of Drug Delivery Systems: Definition, Synthesis and Applications

“…Although polymersomes can be loaded during nanoprecipitation by dissolving API in an appropriate solvent phase, polymersomes can be previously prepared, lyophilized, and loaded during rehydration with an aqueous solution. This approach was used for loading hyaluronic-based HA-PLA polymersomes with the enzyme β-galactosidase [97].…”

“…HA-PLA loaded with β-galactosidase was applied for enzyme replacement therapy (ERT) in a lysosomal storage disorder, GM1 gangliosidosis. Successful uptake of polymersomes by diseased fibroblasts promoted healthy autophagic activity [97].…”

Therapeutic developments for neurodegenerative GM1 gangliosidosis

“…Early pre-clinical trials demonstrate successful delivery of β-gal to the whole brain in vivo post IV injection in GM1-affected felines (Larsen, 2023), with a nine-fold increase in enzyme activity in the cerebellum. ApoE-modified hyaluronic acidb-PLA PSs (Paruchuri et al, 2022;Foster et al, 2024), designed to release β-gal in response to upregulated hexosaminidase A (McCurdy et al, 2014), restored normal autophagic function in GM1-affected cells demonstrating promise toward ERT post BBB-delivery (Paruchuri et al, 2022). Arginase-responsive dextran sulfate/poly-Larginine polymer capsules effectively delivered β-gal to affected mouse and human fibroblasts yielding a restoration to normal GM1 ganglioside levels in all cell lines at a dosage of 50 capsules/cell, but brain delivery was not assessed (Gupta et al, 2017).…”

Polymersome Membrane Engineering with Active Targeting or Controlled Permeability for Responsive Drug Delivery

“…Enzyme-triggered microstructural evolution in polymersome membrane induces controlled permeabilization of bilayer . This architectural transition can be introduced by incorporating enzyme sensitive blocks or moieties like hyaluronic acid (HA), aliphatic ester, or enzymatic cleavage of side chains via elimination and deacetylation reaction. − Generally, enzymes disturb the ratio of hydrophobic/hydrophilic blocks and initiate a vesicle to micelle transition. This morphological destruction facilitates the sustained release of the therapeutic drug.…”