CXCL5 Modified Nanoparticle Surface Improves CXCR2⁺ Cell Selective Internalization

• Main Authors: Roberta Cagliani, Francesca Gatto, Giulia Cibecchini, Roberto Marotta, Federico Catalano, Paola Sanchez-Moreno, Pier Paolo Pompa, Giuseppe Bardi
• Format: Article
• Language: English
• Published: MDPI AG 2019-12-01
• Series: Cells
• Subjects: chemokines; chemokine receptors; immune cells; nanoparticles; surface chemistry
• Online Access: https://www.mdpi.com/2073-4409/9/1/56

Driving nanomaterials to specific cell populations is still a major challenge for different biomedical applications. Several strategies to improve cell binding and uptake have been tried thus far by intrinsic material modifications or decoration with active molecules onto their surface. In the present work, we covalently bound the chemokine CXCL5 on fluorescently labeled amino-functionalized SiO₂ nanoparticles to precisely targeting CXCR2⁺ immune cells. We synthesized and precisely characterized the physicochemical features of the modified particles. The presence of CXCL5 on the surface was detected by z-potential variation and CXCL5-specific electron microscopy immunogold labeling. CXCL5-amino SiO₂ nanoparticle cell binding and internalization performances were analyzed in CXCR2⁺ THP-1 cells by flow cytometry and confocal microscopy. We showed improved internalization of the chemokine modified particles in the absence or the presence of serum. This internalization was reduced by cell pre-treatment with free CXCL5. Furthermore, we demonstrated CXCR2⁺ cell preferential targeting by comparing particle uptake in THP-1 vs. low-CXCR2 expressing HeLa cells. Our results provide the proof of principle that chemokine decorated nanomaterials enhance uptake and allow precise cell subset localization. The possibility to aim at selective chemokine receptor-expressing cells can be beneficial for the diverse pathological conditions involving immune reactions.