Advanced
malignant melanoma is characterized by rapid development, poor prognosis and insensitivity to
chemoradiotherapy.
Immunotherapy has become one of the primary clinical treatments for
malignant melanomas. In recent decades, identifying specific tumour
antigens and the enhanced immunoactivity of tumour
vaccines has become critical for engineering successful tumour
vaccines. As a widely used
vaccine carrier, heat shock protein 70 (HSP70) clearly increases the immunogenicity of tumour
antigens, such as melanoma‑associated
antigen A1 (MAGEA1). Based on previous studies, gas‑filled ultrasound
microbubbles (MBs) were engineered to carry an HSP70‑MAGEA1 fusion
protein (FP). Following
subcutaneous injection around the lymphatic nodes the FP was directly released into the lymph nodes under ultrasonic imaging. The results indicated that the
microbubbles enhanced the immunoactivity of FPs more effectively than HSP70‑MAGEA1 fusion alone. Additionally, HSP70‑MAGEA1 delivered via
microbubbles clearly inhibited and delayed the growth of MAGEA1‑expressing
B16 melanomas in mice and improved the survival times of these animals compared with the fusion
protein alone. The results of the present study demonstrated that controlled MBs enhance the immunoactivity of FPs and also highlights novel, potential
vaccine carriers and a new strategy for engineering controllable tumour
vaccine designs.