Aluminium-Complexed Alginate Nanoparticles as an Adjuvant for Therapeutic Vaccine against Melanoma

Abstract

Therapeutic cancer vaccines elicit an immune response within existing tumours. Our research introduces a strategy to address the low efficacy of peptide-based therapeutic cancer vaccines by employing aluminum-complexed alginate nanoparticles (nAl-Alg) as an adjuvant. Characterisation of nAl-Alg revealed a hydrodynamic diameter of 242.1±126.33 nm. Cytocompatibility studies using the murine macrophage cell line RAW 264.7 demonstrated no change in percentage viability up to 100 µg/ml compared to untreated control. Cell uptake studies conducted in RAW 264.7 macrophages demonstrated an enhnaced uptake of nAl-Alg compared to Alhydrogel® ,a commercially available adjuvant. In vivo toxicity studies in mouse models also revealed the absence of adverse reactions in haematological analysis after treatment with nAl-Alg. Subsequent in vivo mouse melanoma model studies showed a notable delay in tumour growth in animals treated with nAl-Alg combined with tumour antigen compared to groups treated with tumour antigen alone, adjuvant alone, and untreated controls. The median survival time increased from 17 days in untreated animals to 33 days for the nAl-Alg and tumour antigen combination-treated group. Treatment with nAl-Alg and tumour antigen alone resulted in median survival times of 23 days and 24 days respectively. These findings highlight the potential therapeutic impact of nAl-Alg in enhancing the immune response against tumours.