Microneedle-assisted vaccination combined with autophagy regulation for antitumor immunotherapy

Despite vaccination having the potency to revolutionize disease treatments, some critical issues including lack of safe and effective delivery system, insufficient internalization and ineffective antigen cross-presentation by dendritic cells (DCs) severely hamper its extensive clinical applications. Herein, we developed a whole cell-encapsulated antitumor vaccine microneedle patch (TCV-DMNs) potentiated with transdermal co-delivery of granulocyte-macrophage colony-stimulating factor (GM-CSF) and autophagy promoter (Tat-beclin 1). After transdermal vaccination with TCV-DMNs, GM-CSF released from DMNs serves as a potent adjuvant to recruit and promote the phagocytosis of antigens by DCs. Subsequently, Tat-beclin 1 promoted DCs maturation and MHC-I-mediated cross-presentation via up-regulated autophagy of DCs. We found that vaccination with TCV-DMNs could not only effectively suppress melanoma challenge, but also lead to regression of established malignancies, followed by a relapse-free survival of >40 days. Collectively, whole cell-encapsulated microneedle-assisted transdermal vaccination TCV-DMNs in combination with autophagy regulation could induce a robust antitumor immune response via enhancing transdermal delivery efficiency, promoting antigen internalization and cross-presentation, together with boosting T cell activities.