Hyaluronic acid-bilirubin nanomedicine-based combination chemoimmunotherapy

Abstract

Despite significant advances in immune checkpoint blockade (ICB), immunosuppression mediated by tumor-associated myeloid cells (TAMCs) poses a major barrier to cancer immunotherapy. In addition, while immunogenic cell death (ICD) provides a viable approach to inducing anti-tumor immune response, it remains unknown how to effectively trigger ICD while addressing immunosuppressive TAMCs. Here, we show that SC144, a gp130 inhibitor that blocks the IL-6/gp130/STAT3 pathway, induces ICD of tumor cells and polarizes macrophages to M1-phenotype in vitro. However, as SC144 also induces killing of CD8+ T-cells, we sought to deliver SC144 selectively to tumor cells and TAMCs. Toward this goal, we have developed hyaluronic acid-bilirubin nanoparticles (HABN) that accumulate in CD44hi tumor cells and TAMCs. Systemic administration of SC144 loaded in HABN (SC144@HABN) induces apoptosis and ICD of tumor cells, increases the ratio of M1-like to M2-like macrophages, and decreases the frequency of myeloid-derived suppressor cells and CD4+ regulatory T-cells, while promoting anti-tumor CD8+ T-cells. Moreover, SC144@HABN combined with anti-PD-L1 ICB efficiently eliminates MC38 tumors and ICB-resistant 4T1 tumors. Overall, our work demonstrates a therapeutic strategy based on coordinated ICD induction and TAMC modulation and highlights the potential of combination chemoimmunotherapy.

Antioxidative Hyaluronic Acid–Bilirubin Nanomedicine Targeting Activated Hepatic Stellate Cells for Anti-Hepatic-Fibrosis Therapy

“…The HA-BR conjugate was synthesized from an acid form of HA and an amino-ethylene–bilirubin conjugate (AE-BR) using a slightly modified method based on the one previously described by Lee et al , In brief, the acidic form of HA (80 μmol), prepared from the sodium salt form of HA (Lifecore Biomedical) using a dialysis method, and N -hydroxysuccinimide (NHS, 40 μmol) were mixed in DMSO (4.8 mL). After 1-ethyl-3-(3-dimethylaminopropyl)­carbodiimide (EDC, 140 μmol) was added, the solution was mixed for 10 min at RT.…”

“…Synthesis of PEGylated Bilirubin (PEG-BR). The PEG-BR conjugate was synthesized using a slightly modified method based on the one previously described by Lee et al 37,38 For 10 min at RT, BR (75 μmol) and EDC (33.75 μmol) were mixed in DMSO (0.6 mL) containing triethylamine (225 μL) and NHS (52 μmol). Then, poly(ethylene glycol) 20K-amine (15 μmol, 20K-PEG-NH 2 , Nanosoft Polymers) was added, and EDC/NHS chemistry was performed for 4 h under nitrogen gas.…”

“…Synthesis of the HA-BR−Cy5.5 Conjugate. Cy5.5 conjugated HA-BR was synthesized using a slightly modified method based on the one previously described by Lee et al 37,38 In brief, the acidic form of HA-BR (10.5 μmol), prepared from the native sodium salt form of HA-BR through dialysis against 0.01 M HCl and water, was dissolved in DMSO (0.8 mL) overnight. NHS (2 μmol) and EDC (2 μmol) were then added to the mixture and stirred for 10 min at RT.…”

“…Preparation of HABNs, PEG-BNs, and Cy5.5-tagged HABNs. HABNs, PEG-BNs, and Cy5.5-tagged HABNs were synthesized following a method previously described by Lee et al 37,38 HA-BR, PEG-BR, or HA-BR−Cy5.5 were dissolved in water or PBS and then sonicated for 10 min at RT. Finally, HABNs, PEG-BNs, or Cy5.5conjugated HABNs were obtained after filtration through a 0.45 μm filter membrane.…”

“…To overcome those limitations, we developed hyaluronic acid–bilirubin nanoparticles (HABNs) as a promising antifibrotic nanomedicine that achieves CD44-targeting and antioxidant modulation. HABNs are composed entirely of naturally occurring, biocompatible, and biodegradable materials: bilirubin (BR), an endogenous antioxidant and anti-inflammatory bile acid, − ,, and hyaluronic acid (HA), an endogenous glycosaminoglycan biopolymer that targets the CD44 overexpressed on activated HSCs. ,− When they were administered to mice intravenously, the HA shell of the HABNs interacted specifically with CD44, enabling them to target activated HSCs in fibrotic livers but not naive HSCs in healthy livers. Moreover, the BR core conferred potent antioxidant activity, contributing to the beneficial modulation of HSCs.…”