No abstract

No 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.

Microspheres (MS; 1−3 μm) with different degrees of surface roughness were prepared to assess the effects of surface topology on internalization into antigen-presenting cells (APCs; macrophages and dendritic cells). In this study, we demonstrated that the intracellular uptake of MS is readily enhanced by surface modification with nanoparticles or cancer cellderived vesicles (VE) to modulate their surface topology. MS coated with nanovesicles (MS-VE) with high surface roughness was more successfully and efficiently engulfed by APCs, compared with bare MS and those with low surface roughness. Incorporated MPLA within MS-VEs (M/MS-VE) triggered greatly elevated release of immune stimulating cytokines, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), from macrophages and dendritic cells, compared to free MPLA. Taken together, this MS-VE could serve as a platform system for the delivery of immune stimulators and antigens to APCs with negligible toxicity.

No abstract