Cellular Internalization and Inhibition Capacity of New Anti-Glioma Peptide Conjugates: Physicochemical Characterization and Evaluation on Various Monolayer- and 3D-Spheroid-Based in Vitro Platforms

Abstract

Most therapeutic agents used for treating brain malignancies face hindered transport through the blood−brain barrier (BBB) and poor tissue penetration. To overcome these problems, we developed peptide conjugates of conventional and experimental anticancer agents. SynB3 cell-penetrating peptide derivatives were applied that can cross the BBB. Tuftsin derivatives were used to target the neuropilin-1 transport system for selectivity and better tumor penetration. Moreover, SynB3-tuftsin tandem compounds were synthesized to combine the beneficial properties of these peptides. Most of the conjugates showed high and selective efficacy against glioblastoma cells. SynB3 and tandem derivatives demonstrated superior cellular internalization. The penetration profile of the conjugates was determined on a lipid monolayer and Transwell co-culture system with noncontact HUVEC-U87 monolayers as simple ex vivo and in vitro BBB models. Importantly, in 3D spheroids, daunomycin-peptide conjugates possessed a better tumor penetration ability than daunomycin. These conjugates are promising tools for the delivery systems with tunable features.

Modification of Short Non‐Permeable Peptides to Increase Cellular Uptake and Cytostatic Activity of Their Conjugates

“…It is known that fixation of cells may lead to redistribution of peptides, causing them to be localized in the nucleus [64] . However we [65] and others, [66] found that using mild condition for fixation did not alter the internalization pattern of peptides. Thus, fixed cells were used to get a picture about the cellular distribution of peptides.…”

Novel Assay Platform to Evaluate Intracellular Killing of Mycobacterium tuberculosis: In Vitro and In Vivo Validation

“…In this study, we have employed a modified method based on ( 55 ). Briefly, micromolds for casting 3D Petri dishes (MicroTissues, Sigma, 5 × 7 array) were filled with molten agarose (2% ( w / v ) in PBS).…”

“…Prior to seeding process, nuclei were stained with Hoechst 33342 solution (0.2 µM) for 30 min (Figure 2). Based on our previous work (55), the nuclear stain could not successfully penetrate into deeper layers of the spheroids (mostly localized at the spheroid surface), and towards the center of the spheroids the Hoechst 33342 signal was gradually decreasing. Stained cells were incubated in 2 ml DMEM CM for 48 h while cell-to-cell adhesion drives the aggregation and formation of spheroids.…”

Dithiolane quartets: thiol-mediated uptake enables cytosolic delivery in deep tissue

“…1a). 2,[21][22][23][24][25][26][27] This mechanism allows the TfR to efficiently penetrate tumors and cross the blood-brain barrier to deliver iron to the brain. The attachment of transferrin or ligands of other transcytosis receptors to operational transport systems has been shown to improve delivery into deep tissue.…”

“…The attachment of transferrin or ligands of other transcytosis receptors to operational transport systems has been shown to improve delivery into deep tissue. 2,[21][22][23][24][25][26][27] Evidence is emerging that the TfR also participates in thiolmediated uptake [28][29][30][31][32] and viral entry, 28,33,34 including oligonucleotide phosphorothioates 35 and SARS-CoV-2, 28,34 respectively (Fig. 1b).…”