Cisplatin-Loaded M1 Macrophage-Derived Vesicles Have Anti-Cancer Activity in Osteosarcoma

Area of Science:

• Biomedical Engineering
• Oncology
• Immunology

Background:

• Osteosarcoma (OS) is a rare bone cancer in young adults with high mortality.
• Current treatments like cisplatin have toxic side effects and limited efficacy.
• Immunotherapy is hindered by a non-antigenic tumor microenvironment.

Purpose of the Study:

• To develop and evaluate cisplatin-loaded M1 macrophage-derived vesicles (C-MVs) as a novel therapeutic strategy for osteosarcoma.
• To assess the anti-cancer efficacy, toxicity, and immunomodulatory effects of C-MVs in vitro and in vivo.

Main Methods:

• Manufactured M1 macrophage-derived vesicles (MVs), both empty (E-MVs) and cisplatin-loaded (C-MVs), using human and mouse macrophages.
• Evaluated C-MV efficacy and DNA damage in human OS cell lines compared to free cisplatin.
• Assessed C-MV tumor accumulation, anti-cancer effects, survival, toxicity, and immunomodulation (M1/M2 ratio, TNF-α) in an OS tibia xenograft mouse model.

Main Results:

• C-MV treatment showed lower IC50 values and equivalent DNA damage in OS cells versus free cisplatin.
• C-MVs effectively accumulated in tumors and significantly reduced tumor burden and prolonged survival in mice.
• C-MV treatment did not induce the systemic toxicities (weight loss, renal/hepatic damage) observed with free cisplatin.
• Both E-MVs and C-MVs modulated the tumor microenvironment, increasing the M1/M2 macrophage ratio and serum TNF-α levels.

Conclusions:

• Cisplatin-loaded MVs represent a promising, less toxic alternative for osteosarcoma treatment.
• C-MV therapy demonstrates significant anti-tumor activity and potential for immune system enhancement.
• Further development of C-MV technology is warranted for clinical application in osteosarcoma therapy.