Publications

Targeting therapeutic nanocarriers (NCs) to endothelial receptors favours transport across the blood-brain barrier (BBB), a main obstacle to access the brain. While these strategies compel validation in animals, quantitative sub-cellular resolution is non-viable in vivo. BBB-on-chip (BBB-oC) devices can help. Illustrating this, we used a BBB-oC comprising a lateral channel containing a human brain endothelial lining and a central chamber containing hydrogel-embedded pericytes and astrocytes. We studied NCs targeting intercellular adhesion molecule-1 (ICAM-1), a cell-surface protein overexpressed in pathology and involved in CAM-mediated transport. Brain access was validated in vivo after injection of NCs coated with anti-ICAM-1 vs. control IgG. ICAM-1 expression was verified in vitro using endothelial cells, pericytes, and astrocytes (756-, 511-, 690-fold over non-specific signal under TNF alpha). VE-cadherin presence and lack of dextran leakage demonstrated a restrictive BBB-oC barrier. Data showed endothelial targeting of anti-ICAM-1 NCs (428 NCs/cell at 1 h), uptake (60% of cell-interacting NCs), and transcytosis (90%; 24 h) downregulated by a CAM-pathway inhibitor (88% decay; 1 h). Non-transcyosed NCs trafficked to lysosomes, while transcytosed NCs interacted with pericytes and astrocytes (2643 NCs/cell; 24 h) and entered them (90% of transcytosed NCs). This BBB-oC represents a valuable model to evaluate ICAM-1-mediated transcytosis, complementing animal studies.

JTD Keywords: Blood-brain barrier, Design, Drug-delivery, Endothelial and basolateral interactions, Endothelium, Icam-1 targeting, Icam-1-targeted nanocarriers, Nanoparticles, Organ-on-a-chip, Targeted nanocarriers, Transcytosis mechanism, Transport

Poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs) enhance the delivery of therapeutic enzymes for replacement therapy of lysosomal storage disorders. Previous studies examined NPs encapsulating or coated with enzymes, but these formulations have never been compared. We examined this using hyaluronidase (HAse), deficient in mucopolysaccharidosis IX, and acid sphingomyelinase (ASM), deficient in types A–B Niemann–Pick disease. Initial screening of size, PDI, ζ potential, and loading resulted in the selection of the Lactel II co-polymer vs. Lactel I or Resomer, and Pluronic F68 surfactant vs. PVA or DMAB. Enzyme input and addition of carrier protein were evaluated, rendering NPs having, e.g., 181 nm diameter, 0.15 PDI, −36 mV ζ potential, and 538 HAse molecules encapsulated per NP. Similar NPs were coated with enzyme, which reduced loading (e.g., 292 HAse molecules/NP). NPs were coated with targeting antibodies (> 122 molecules/NP), lyophilized for storage without alterations, and acceptably stable at physiological conditions. NPs were internalized, trafficked to lysosomes, released active enzyme at lysosomal conditions, and targeted both peripheral organs and the brain after i.v. administration in mice. While both formulations enhanced enzyme delivery compared to free enzyme, encapsulating NPs surpassed coated counterparts (18.4- vs. 4.3-fold enhancement in cells and 6.2- vs. 3-fold enhancement in brains), providing guidance for future applications.

JTD Keywords: active enzymes, encapsulation, enhanced delivery, enzyme therapeutics, formulation parameters, icam-1 targeting, icam-1-targeted nanocarriers, in vivo biodistribution, in-vitro, lysosomal delivery, model, oral delivery, plga nanoparticles, poly(lactic-co-glycolic acid) nanoparticles, protein therapeutics, surface loading, Acid sphingomyelinase, Animals, Encapsulation, Enzyme replacement therapy, Enzyme therapeutics, Icam-1 targeting, In vivo biodistribution, Lysosomal delivery, Lysosomes, Mice, Nanoparticles, Poly(lactic-co-glycolic acid) nanoparticles, Polymers, Surface loading, Surface-active agents