Nanocarriers for Protein Delivery to the Cytosol: Assessing the Endosomal Escape of Poly(Lactide-co-Glycolide)-Poly(Ethylene Imine) Nanoparticles

Abstract

Therapeutic proteins and enzymes are a group of interesting candidates for the treatment of numerous diseases, but they often require a carrier to avoid degradation and rapid clearance in vivo. To this end, organic nanoparticles (NPs) represent an excellent choice due to their biocompatibility, and cross-linked enzyme aggregates (CLEAs)-loaded poly (lactide-co-glycolide) (PLGA) NPs have recently attracted attention as versatile tools for targeted enzyme delivery. However, PLGA NPs are taken up by cells via endocytosis and are typically trafficked into lysosomes, while many therapeutic proteins and enzymes should reach the cellular cytosol to perform their activity. Here, we designed a CLEAs-based system implemented with a cationic endosomal escape agent (poly(ethylene imine), PEI) to extend the use of CLEA NPs also to cytosolic enzymes. We demonstrated that our system can deliver protein payloads at cytoplasm level by two different mechanisms: Endosomal escape and direct translocation. Finally, we applied this system to the cytoplasmic delivery of a therapeutically relevant enzyme (superoxide dismutase, SOD) in vitro.

Poly(Lactide‐Co‐Glycolide) Nanoparticles Co‐Loaded with Chlorophyllin and Quantum Dots as Photodynamic Therapy Agents

“…NPs loaded with only QDs, Chl, or empty were also produced as controls. All the obtained NPs display hydrodynamic diameters ranging from 169 to 220 nm, that are typical of PLGA NPs obtained with this technique, [23,24] indicating small or negligible effect of either QDs or Chl on NP formation. Additionally, the zeta potential of all NPs is negative and around À 30 mV, as expected (Table S1).…”

Brain-targeted enzyme-loaded nanoparticles: A breach through the blood-brain barrier for enzyme replacement therapy in Krabbe disease

“…This was independent of the type of ligand and also of the type of cell, since similar results were obtained in TWI and WT fibroblasts. This means that, while the targeting peptides should address NPs to a certain district in the organism, at the cellular level, they do not affect the expected fate of NPs, which in this case leads to the endolysosomal route ( 27 ). Together, our results indicate that GALC CLEA NPs can successfully vehiculate the enzyme inside cells and accumulate in the lysosomes, where GALC is supposed to perform its physiological activity, and that the preferred localization of delivered GALC in the lysosomes is not affected by the presence of targeting ligands on the carrier’s surface.…”

Engineering Tumor-Targeting Nanoparticles as Vehicles for Precision Nanomedicine

“…Therefore, in the case of clathrin-mediated uptake, endosomal escape of NPs must occur prior to lysosome degradation [56]. Using poly(ethyleneimine) (PEI), Galliani et al were able to show successful endosomal escape and cytoplasmic delivery of their nanoparticle cargo [58]. Actively targeting NPs to tumor-overexpressed receptors may also enable receptor-mediated cellular internalization without degradation by lysosomal compartments.…”