Multi-faceted nanodrug reinforcing metalloimmunotherapy for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a major cause of cancer-related deaths, with limited options for unresectable cases. Immunotherapies show promise but are hindered by the immunosuppressive tumor microenvironment (TME). This study developed cobalt-Lenvatinib combination nanoclusters (Co+Len@OVA) to enhance HCC immunotherapy. These nanoclusters, formed by self-assembling ovalbumin, Lenvatinib, and cobalt ions, effectively inhibited HCC progression and reduced immunosuppression. They accumulated at tumor sites, inducing immunogenic cell death and activating the STING-IFNß pathway, leading to a potent antitumor immune response. Additionally, they normalized tumor vasculature, improving anti-PD1 antibody retention and penetration. Combining Co+Len@OVA with anti-PD1 therapy significantly reduced HCC tumor volume more effectively than conventional treatments. Our study shows that Co+Len@OVA nanoclusters offer a promising treatment for HCC, particularly when surgery is not an option. They combine cobalt-mediated metalloimmunotherapy with Lenvatinib and boost the effectiveness of anti-PD1 therapy. Overall design: Mice with in-situ Hepa1-6-luc cell-derived HCC were randomly allocated into six treatment groups: Control, OVA+anti-PD1, Lenvatinib+anti-PD1, Len@OVA+anti-PD1, Co+Len@OVA+anti-PD1, and Co@OVA+anti-PD1. These mice received tail vein injections of drug-loaded nanoclusters (2 mg/mL) or free Lenvatinib (equivalent to the nanocluster concentration) along with anti-PD1 (50 µg per injection) every 4 days, while the nanoclusters or free Lenvatinib were administered every 3 days. On day 14, tumor tissues from the Control, Lenvatinib+anti-PD1, and Co+Len@OVA+anti-PD1 groups (n = 3 per group) were harvested for mRNA extraction using TRIzol reagent. Sequencing libraries were prepared, and 2×150bp double-end sequencing was conducted using Illumina Novaseq™ 6000.