GSE185997
pH-Degradable, Bisphosphonate-Loaded Nanogels Repolarize Immunosuppressive Macrophages Towards Antifibrotic Liver Therapy
Liver fibrosis is a hard-to-treat disease with liver transplantation as only effective curation to this date. During disease progression, immune suppressive macrophages dominate and support fibrosis formation by replacement of functional parenchyma with collagen-dominating scare tissue. To alter the macrophage behavior, a pH-degradable, nanogel-based delivery system was developed for the covalent conjugation of the clinically approved bisphosphonate alendronate. The nanocarrier mediates the drugs' delivery into hepatic nonparenchymal cells after intravenous administration and, thereby, triggers a macrophage repolarization against fibrosis progression. This approach may provide a significant contribution to establish further nanotherapeutic delivery strategies to effectively treat liver fibrosis. Immune suppressive macrophages contribute to the progression of several diseases including cancer and fibrosis. Especially in chronically damaged liver tissues they trigger the replacement of functional parenchyma by collagen-dominating scare tissue. In this study, we aimed to intervene into this cascade by repolarizing the macrophage phenotype via a pH-degradable, squaric ester-based nanogel carrier system. This nanotechnology platform enables a selective covalent conjugation of the highly water-soluble bisphosphonate alendronate and, thus, its safe and efficient delivery to hepatic nonparenchymal cells of fibrotic livers after intravenous administration. The bisphosphonate triggers a reprogramming of profibrotic M2- towards antifibrotic M1-phenotype macrophages affording an fibrolytic outcome, as verified both on mRNA and protein level. Further insights by genomic and proteomic studies confirm the macrophages' repolarization and thus corroborate the virtue of the nanogels as biocompatible nanocarrier platform for hepatotropic bisphosphonate delivery. Beyond preventing liver fibrosis progression, these nanogels may therefore represent an attractive device for further nanotherapeutic interventions in M2-type macrophage dominating diseases. Overall design: AL/NP treatment versus control (samples alnp_R1-alnp_R3, ctrlfib_R1-ctrlfib_R3)