Cell Penetrating Peptide-Based Redox-Sensitive Vaccine Delivery System for Subcutaneous Vaccination

In immunotherapy, induction of potent cellular immunity by vaccination is essential to treat intracellular infectious diseases and tumors. In this work, we designed a new synthetic peptide carrier, Cys-Trp-Trp-Arg₈-Cys-Arg₈-Cys-Arg₈-Cys, for vaccine delivery by integrating a redox-responsive disulfide bond cross-linking and cell-penetrating peptide arginine octamer. The carrier peptide bound to the antigen protein ovalbumin (OVA) via electrostatic self-assembly to form peptide/OVA nanocomposites. Then, the spontaneous oxidization of the thiols of the cysteine residues induced interpeptide disulfide bond cross-linking to construct denser peptide/OVA condensates. The cell-penetrating peptides incorporated in the carrier peptide could increase antigen uptake by antigen presenting cells. After being internalized by antigen presenting cells, the antigen could be rapidly released in cytoplasm along with degradation of the disulfide bonds by intracellular glutathione, which could promote potent CD8⁺ T cell immunity. The cross-linked peptide/OVA condensates were used for subcutaneous vaccination. The results showed that the peptide carrier mediated potent antigen-specific immune response by significantly increasing IgG titer; splenocyte proliferation; the secretion level of cytokines INF-γ, IL-12, IL-4, and IL-10; immune memory function, and the activation and maturation of dendritic cells. From the results, the low-molecular weight vaccine-condensing peptide with definite chemical composition could be developed as a novel class of vaccine delivery systems

Tumor-Penetrating Peptide-Functionalized Redox-Responsive Hyperbranched Poly(amido amine) Delivering siRNA for Lung Cancer Therapy

Biosafety and the targeting ability of gene delivery systems are critical aspects for gene therapy of cancer. In this study, we report the synthesis and use of redox-responsive poly­(amido amine) (PAA) with good biocompatibility and biodegradation as a gene carrier material. A tumor-specific tissue penetration peptide, internalizing-RGD (iRGD) was then conjugated to PAA with an amidation reaction. In experiments using H1299 cells, PAA-iRGD was found to have a lower cytotoxicity and higher cellular uptake efficiency compared to PAA. An siRNA, specific to epidermal growth factor receptor (EGFR) that is overexpressed on the lung cancer cell surface and often targeted in lung cancer treatment, was designed to silence EGFR (i.e., siEGFR) for delivery by the gene carrier PAA-iRGD. <i>EGFR</i> gene silencing, apoptosis, antiproliferation, and antitumor effects of PAA-iRGD/siEGFR were evaluated <i>in vitro</i> and <i>in vivo</i>. PAA-iRGD/siEGFR displayed a much higher gene silencing ability compared to PAA and polyethylenimine (25 kDa), significantly inhibited the proliferation and migration of H1299 cells, and elicited significant cell apoptosis. Moreover, intravenously injected PAA-iRGD/siEGFR inhibited lung tumor growth <i>in vivo</i>. These results suggest that PAA-iRGD with good biocompatibility, biodegradation, and targeting ability could be a promising gene delivery system for gene therapy of cancers

Effect of coupling dispersion on the phase response curve (PRC) of the network.

<p>Shown are PRCs with coupling dispersions (<b>A</b>), (<b>B</b>), and (<b>C</b>). Although the network shows relatively larger phase advances and delays with increased coupling dispersion, the area under the phase delay zones is greater than that under the advance zones. The PRCs were similar for all the values of .</p

Period of the mean fields of VL and DM in the <i>p</i>−<i>K_f</i> plane.

<p>The case for the 22-h T cycle is shown for VL (<b>A</b>) and DM (<b>B</b>), and the case for the 26-h T cycle is shown for VL (<b>C</b>) and DM (<b>D</b>). The coupling strengths are identical for all the oscillators (i.e., η = 0). Entrainment of the sub-network to the 22-h cycle is represented by the yellow region, and entrainment of the sub-network to the 26-h cycle is represented by the blue region.</p

Effect of coupling dispersion on the ratio of the area of the delay zone to the advance zone.

<p>The ratio increases with increasing coupling dispersion.</p

Effect of coupling dispersion on the period of the mean fields of VL and DM in the <i>p</i>−<i>K_f</i>

<p><b>plane.</b> The case for the 22-h T cycle is shown for VL (<b>A</b>) and DM (<b>B</b>) with and for VL (<b>C</b>) and DM (<b>D</b>) with . The corresponding case for the 26-h T cycle is represented in (<b>E</b>) - (<b>H</b>).</p

Effect of coupling dispersion on the order parameter of the network.

<p>The case for the 22-h T cycle is shown with coupling dispersion (<b>A</b>) and (<b>B</b>), and the case for the 26-h T cycle is shown with coupling dispersion (<b>C</b>) and (<b>D</b>).</p

Mean field oscillations of VL and DM during a 22-h T cycle.

<p>(<b>A</b>) VL follows the T cycle, whereas DM free runs for the parameters and . (<b>B</b>) Both VL and DM follow the T cycle for the parameters and . The dispersion of the coupling strengths, η, is set to zero in both (<b>A</b>) and (<b>B</b>). The grey bar indicates the dark phase, and the white bar the light phase, of the T cycle.</p

The effect of noise on the collective behavior of the SCN neuronal oscillators in the case of weak coupling.

<p>(A) The effect of noise on the synchronization degree <i>R</i> between the oscillators. (B) The effect of noise on the period <i>T</i> of the SCN network. The minimal noise intensity <i>D</i>_<i>m</i> is 0.36, at which <i>R</i> reaches 0.5. <i>g</i> represents the coupling strength.</p

Effect of coupling dispersion on the critical <i>p</i>.

<p>Shown are the cases for the 22-h (<b>A</b>) and 26-h (<b>B</b>) T cycles.</p