Macrophage Repolarization Using Chrysin-Based PCL-PEG Electrospun Nanofibrous Scaffold: Possible Application in RegenerativeMedicine

Background and Aim: In the regenerative medicine therapies, theavailability of engineered scaffolds that modulate inflammatory statesis highly required. The aim of this study was to evaluate the efficiencyof electrospun nanofibrous scaffolds containing natural substanceswith anti-inflammatory properties such as chrysin (Chr) to controlinflammation and re-polarization of macrophages toward M2 antiinflammatoryphenotype.Methods: For this purpose, Chr-blended PCL/PEG electrospunnanofibrous mats were successfully fabricated and characterized usingfield emission scanning electron microscopy (FE-SEM) and Fouriertransforminfrared spectroscopy (FT-IR). MTT assay and FE-SEM wereused to assess the possible effect of EO-loaded PCL/PEG nanofibrous maton the morphology and viability of polarized RAW264.7 macrophagesafter 72 hours incubation. Also, the in vitro efficiency of Chr-loaded PCL/PEG nanofibrous mat to modulate macrophage polarization from M1 toM2 phenotype through alteration in the expression levels of M1 marker(iNOS2) and M2 marker (Arg1) as well as the expression levels of proinflammatorycytokines including TNF-α, IL-1β, and IL-6 were measuredusing real-time PCR and ELISA.Results: MTT results showed that macrophage viability on bead freeand smooth Chr-PCL/PEG electrospun nanofibers was higher than onPCL/PEG nanofibers and control (P < 0.05). Additionally, stimulatedmacrophages on Chr-PCL/PEG nanofibers were observed to be round,pancake-like shape with few cytoplasmic projections and low spreadingwithin in 3-day culturing indicating an M2 phenotype of macrophages.qPCR results showed a reduction in iNOS-2 and an increase in Arg-1levels of macrophages seeded on Chr-PCL/PEG nanofibers, representingthe successful polarization of the macrophages to M2 phenotype. Thechange in macrophage phenotype on Chr-based nanofibers couldsuppress the inflammation in LPS/ IFN-γ stimulated macrophages asevidenced by a major reduction in pro-inflammatory cytokine levelsTNF-α, IL-1β, and IL-6.Conclusion: Conclusively, the results demonstrated that Chr-basednanofibers efficiently modulated RAW264.7 macrophage polarity towardan anti-inflammatory M2 phenotype.

کلیدواژه ها:

Chrysin ، Nanofiber ، Macrophage polarity ، Regenerative medicine