T Cell-Association of Carboxy-Terminal Dendrimers with Different Bound Numbers of Phenylalanine and Their Application to Drug Delivery

Abstract

T cells play important roles in various immune reactions, and their activation is necessary for cancer immunotherapy. Previously, we showed that polyamidoamine (PAMAM) dendrimers modified with 1,2-cyclohexanedicarboxylic acid (CHex) and phenylalanine (Phe) underwent effective uptake by various immune cells, including T cells and their subsets. In this study, we synthesized various carboxy-terminal dendrimers modified with different bound numbers of Phe and investigated the association of these dendrimers with T cells to evaluate the influence of terminal Phe density. Carboxy-terminal dendrimers conjugating Phe at more than half of the termini exhibited a higher association with T cells and other immune cells. The carboxy-terminal Phe-modified dendrimers at 75% Phe density tended to exhibit the highest association with T cells and other immune cells, which was related to their association with liposomes. A model drug, protoporphyrin IX (PpIX), was encapsulated into carboxy-terminal Phe-modified dendrimers, which were then used for drug delivery into T cells. Our results suggest the carboxy-terminal Phe-modified dendrimers are useful for delivery into T cells.

Structural Optimization of Carboxy-Terminal Phenylalanine-Modified Dendrimers for T-Cell Association and Model Drug Loading

“…Therefore [33]. In our previous report, we demonstrated that the Phe density at the dendrimer terminus affects the cellular interactions in PAMAM-CHex-Phe [29]. The most stable molecular structures of PAMAM-CHex-Phe, PAMAM-Ph-Phe, and PAMAM-C 6 -Phe, whose dendrimer contains four termini, were calculated and presented in Figure 4.…”

Gene Delivery into T‐Cells Using Ternary Complexes of DNA, Lipofectamine, and Carboxy‐Terminal Phenylalanine‐Modified Dendrimers

“…Transfection: Jurkat cells were cultured in RPMI-1640 medium containing 10% FBS and a penicillin-streptomycin mixture. [13,14] Jurkat cells (1.0 × 10 5 cells per well) were seeded in a 24-well plate. Then, 50 μL of the solutions containing binary and ternary complexes (DNA 0.5 μg per well) was added to each well.…”

“…[10][11][12] A carboxy-terminal PAMAM dendrimer of G4 bearing both 1,2-cyclohexanedicarboxylic acid (CHex) and phenylalanine (Phe), named G4-CHex-Phe, is highly associated with immune cells, including spleen-and lymph nodederived T-cells and Jurkat cells. [12][13][14] Confocal microscopic analysis indicated that G4-CHex-Phe was internalized by T-cells, which is useful for drug delivery into T-cells. [13,14] In this study, we used G4-CHex-Phe to deliver pDNA into T-cells.…”

“…[12][13][14] Confocal microscopic analysis indicated that G4-CHex-Phe was internalized by T-cells, which is useful for drug delivery into T-cells. [13,14] In this study, we used G4-CHex-Phe to deliver pDNA into T-cells. Because G4-CHex-Phe is an anionic molecule with several nanometers in size, DNA cannot be encapsulated in the dendrimer or directly associated with the dendrimer.…”

Dendrimers for Drug Delivery: Where Do We Stand in 2023?

“…Species bearing phenylalanine at more than half of the termini exhibited a higher association with T cells and other immune cells, with the highest affinity being reported to occur at 75% grafting. The robustness of the functionalized dendrimer as a drug vehicle was demonstrated by the successful delivery of a model drug, protoporphyrin IX (PpIX) into T cells [ 6 ]. These findings can be important for the development of dendrimer-based tools for immunotherapy.…”