Amphiphilic Polymeric Nanoparticles Modified with a Protease-Resistant Peptide Shuttle for the Delivery of SN-38 in Diffuse Intrinsic Pontine Glioma

Abstract

Diffuse intrinsic pontine glioma (DIPG) is a chemo-resistant, incurable pediatric tumor of the central nervous system (CNS). The blood−brain barrier (BBB) remains intact in the course of the disease, preventing drugs from entering the brain and resulting in therapeutic failure. The topoisomerase I inhibitor SN-38 shows strong anticancer activity in a patient-derived DIPG cell line in vitro, though a low CNS bioavailability and anti-DIPG efficacy in vivo. In this work, we produced SN-38-loaded polymeric nanoparticles of an amphiphilic chitosan (CS)-g-poly(methyl methacrylate)-poly(acrylic acid) copolymer that were surface-modified with a peptide shuttle that improves transport across the BBB. Drug-loaded nanoparticles displayed a size of ∼200 nm (intensity distribution) and a ζ-potential of +16 mV. The cytocompatibility and endocytosis assayed in DIPG cells (both attached and in suspension) indicated that the nanoparticles are compatible and mainly internalized by clathrin-mediated endocytosis and that the anticancer activity of SN-38 is preserved after nanoencapsulation. In addition, a tandem permeability/anticancer activity study utilizing a coculture model of BBB endothelial cells and DIPG cell spheroids demonstrated that the modified nanoparticles cross a BBB endothelial cell monolayer to a higher extent than the unmodified counterparts and are taken up by DIPG cells. After 72 h of exposure, both SN-38-loaded nanoparticles killed ∼84-88% of the DIPG cells in suspension, indicating that they reach a concentration above the inhibitory concentration 50 of the drug. Finally, the brain accumulation of the drug-loaded nanoparticles upon intravenous injection to Hsd:ICR mice was preliminarily characterized by light sheet fluorescence microscopy. As opposed to unmodified SN-38-loaded nanoparticles, the modified counterparts bind the brain blood vessels and accumulate in the cerebral parenchyma to a large extent. These results confirm the potential of this nanotechnology platform to deliver anticancer agents to the brain in DIPG and other brain tumors with fully conserved BBB. KEYWORDS: diffuse intrinsic pontine glioma (DIPG), amphiphilic polymeric nanoparticles, peptide shuttles, targeting of the central nervous system (CNS)

Nanoparticles for Drug and Gene Delivery in Pediatric Brain Tumors’ Cancer Stem Cells: Current Knowledge and Future Perspectives

“…To increase CNS bioavailability, the authors designed SN-38 loaded NPs of amphiphilic chitosan (CS)-g-poly (methyl methacrylate)-poly (acrylic acid) copolymer that was surface-modified with peptide to improve BBB transport. Their results confirmed the anti-DIPG efficacy of SN-38 NPs to kill almost 85% of stem-enriched DIPG cells and to successfully cross the BBB endothelium (in vitro) [ 82 ]. A dual targeting of CSCs niche (via curcumin) and bulk tumor cells (via doxorubicin) were developed by Xu and colleagues in the context of a glioma tumor.…”

Heterocellular spheroids of the neurovascular blood-brain barrier as a platform for personalized nanoneuromedicine

“…In a previous work, we demonstrated that the permeability of fluorescently labeled dextran (average molecular weight of 40,000 g/mol, 0.001% w/v), a probe used to estimate the tightness of the BBB endothelium in vitro, is in the same range measured for other dextrans (Bukchin et al, 2020(Bukchin et al, , 2021. Based on immunostaining and RNA-Seq data, we anticipated that BBB endothelial cells cultured in 5-cell spheroids display even lower permeability than those in 2D monoculture systems.…”

“…Our previous investigations conducted with primary rat cells suggested that neither forebrain nor olfactory neurons internalize polymeric NPs (Kumarasamy and Sosnik, 2019) and that, without the surface modification with a peptide shuttle, some of them cross the BBB in vitro and in vivo to a limited extent (Bukchin et al, 2020(Bukchin et al, , 2021. Conversely, they were internalized by primary microglia in vitro (Kumarasamy and Sosnik, 2019).…”

Galactomannan-graft-poly(methyl methacrylate) nanoparticles induce an anti-inflammatory phenotype in human macrophages

“…17 These nanocarriers have been profusely investigated in the targeted treatment of cancer and other diseases by different administration routes. [18][19][20][21] Their surface can also be engineered to selectively bind specific receptors overexpressed by macrophages (e.g., mannose receptor, C-type lectin-like receptor), facilitating their uptake through various energy-dependent pathways. 22 Galactomannans (GMs) are natural nonionic biocompatible and biodegradable polysaccharides of b-(1-4)-linked b-D-mannopyranose backbone with single 1-6-linked a-D-galactopyranose branches 23,24 and it has been granted the ''generally recognized as safe'' status by the US Food and Drug Administration and thus, has found applications in the food, pharmaceutical and biomedical industries.…”

“…17 These nanocarriers have been profusely investigated in the targeted treatment of cancer and other diseases by different administration routes. 18–21 Their surface can also be engineered to selectively bind specific receptors overexpressed by macrophages ( e.g. , mannose receptor, C-type lectin-like receptor), facilitating their uptake through various energy-dependent pathways.…”