Polydopamine-Coated Porous Microspheres Conjugated with Immune Stimulators for Enhanced Cytokine Induction in Macrophages

Abstract

Polydopamine-coated porous microsphere (PPM) is investigated as a simple and versatile immobilization strategy for immune-stimulating biomolecules to enhance delivery efficiency and immune-stimulating effects such as cytokine induction in macrophages. The PPMs, with diameters of about 2 μm, exhibit simultaneous and efficient incorporation of biomolecules (nucleotides and proteins), which is comparable to that achieved using microspheres carrying biomolecules internally by virtue of their porous structure. Ovalbumin-conjugated PPMs are internalized into macrophages efficiently and selectively via the phagocytic pathway, without any noticeable toxicity. Internalized CpG oligodeoxynucleotide (ODN)-conjugated PPMs (PPM-CpG) greatly enhance the induction of selected cytokines (TNF-α and IL-6) in RAW 264.7 cells compared to that by the soluble CpG ODN and ionic complexes. Therefore, PPMs generated in this study may serve as effective carriers of immune-stimulating biomolecules such as diverse toll-like receptor agonists.

CpG incorporated DNA microparticles for elevated immune stimulation for antigen presenting cells

“…In previous studies, CpG delivery by carrier systems induced much lower amounts of IL-6 than TNF-α. 22,43 The extent of IL-6 release by DNA-MP-0.5 was similar to that of previously reported 0.3 μm CpG based nanostructures, while DNA-MP-1.0 showed greatly enhanced IL-6 release compared to submicron sized 0.3 and 0.5 μm particles. 20 Taken together, it should be also noted that CpG-based DNA-MP-1.0 exhibited particularly superior activity for IL-6 induction.…”

“…CpG 1826 was selected from diverse model CpG ODN sequences 22 and was obtained from Bioneer (Daejeon, South Korea) as shown in Table 1 . Another five types of ODNs were purchased from Integrated DNA Technologies (Coralville, Iowa, USA).…”

Efficient Delivery of Tyrosinase Related Protein‐2 (TRP2) Peptides to Lymph Nodes using Serum‐Derived Exosomes

“…To determine whether free TRP2 and EXO‐TRP2 was internalized into cells via a similar mechanism, samples were treated in the presence of cytochalasin B (Cyto B), an actin polymerization inhibitor . As shown in Figure b, fluorescence intensities of internalized EXO‐TRP2 into RAW264.7 cells in the absence and in the presence of Cyto B was 589.8 ± 175.5 and 264.8 ± 51.4 after 4 h treatment, respectively.…”

PLGA Microspheres Coated with Cancer Cell-Derived Vesicles for Improved Internalization into Antigen-Presenting Cells and Immune Stimulation

“…The cellular fluorescence intensity of nanoparticle/CM-FITC complexes was 1.7-fold higher at a heparin/CM-FITC weight ratio of 0.5 than that of CM-FITC. Considering that internalization of PLGA MS (1–3 μm) with similar surface charges into Raw264.7 cells was significantly inhibited by treatment with cytochalasin B in our previous study, CM-FITC particles might be internalized mainly via phagocytic pathway …”