Macrophage polarization in vitro and in vivo modified by contact with fragmented chitosan hydrogel

Ysander von Boxberg (1, 2) , Sylvia Soares (1, 2) , Camille Giraudon (1, 2) , Laurent David (3) , Maud Viallon (3) , Alexandra Montembault (3) , Fatiha Nothias (1, 2)

1 NPS - Neuroscience Paris Seine
2 NPS - Régénération et croissance de l'axone = Axonal Growth and Regeneration
3 IMP - Ingénierie des Matériaux Polymères

We have previously shown that implantation of a fragmented chitosan hydrogel suspension (chitosan-FPHS) into a traumatic spinal cord lesion in adult rats led to significant axon regrowth and functional recovery, which was associated to a modulation of inflammation. Using an in vitro culture system, we show here that polarization of bone marrow-derived macrophages is indeed modified by direct contact with chitosan-FPHS. Reducing the degree of acetylation (DA), and raising the concentration of chitosan (Cp, from 1.5% to 3%), favors macrophage polarization towards anti-inflammatory subtypes. These latter also migrate and adhere efficiently on low, but not high DA chitosan-FPHS, both in vitro and in vivo, while inflammatory macrophages rarely invade a chitosan-FPHS implant in vivo, no matter the DA. Our in vitro model setup should prove a valuable tool for screening diverse biomaterial formulations and combinations thereof for their inflammatory potential prior to implantation in vivo.

Mots clés: chitosan hydrogel; acetylation degree; inflammation; bone marrow macrophages; cell culture; spinal cord injury; chitosan hydrogel

Domaines: Sciences du Vivant [q-bio]

Ysander von Boxberg, Sylvia Soares, Camille Giraudon, Laurent David, Maud Viallon, et al.. Macrophage polarization in vitro and in vivo modified by contact with fragmented chitosan hydrogel. Journal of Biomedical Materials Research Part A, 2022, 110 (4), pp.773-787. ⟨10.1002/jbm.a.37326⟩. ⟨hal-03414668⟩