Immunologically effective poly(D-lactic acid) nanoparticle enhances anticancer immune response

Chiral materials with the same atomic compositions exhibit different chemical,physical,and biological properties because of their distinct spatial structures.Herein,a chiral strategy was proposed to develop poly(lactic acid)(PLA)nanoparticle as an efficient nanoadjuvant to activate adaptive anticancer immunity.Two chiral nanovaccines were prepared by directly mixing amino-terminated PLA(PLLA-NH2 or PDLA-NH2)with the model protein antigen ovalbumin(OVA).After being injected into mice subcutaneously,both nanovaccines efficiently migrated to the lymph nodes to initiate the sequential anticancer immune responses.Compared with the PLLA nanovaccine(PLLA-OVA),the PDLA one(PDLA-OVA)contributed to more robust dendritic cell(DC)maturation,antigen presentation,and T lymphocyte activation.In addition to the activation of cellular immunity,PDLA-OVA also triggered a more vigorous activation of humoral immunity,which induced the production of more anti-OVA immunoglobulin G(IgG)than PLLA-OVA.When used as prophylactic or therapeutic nanovaccine toward murine melanoma models,PDLA-OVA triggered more potent adaptive anticancer immune responses that more effectively inhibited the cancer genesis and progression,indicating the significant potential of immunologically effective PDLA nanoadjuvant in cancer immunotherapy.

Chiral polypeptide nanoparticles as nanoadjuvants of nanovaccines for efficient cancer prevention and therapy

The chirality of bioactive molecules is closely related to their functions.D-amino acids commonly distributed in the bacterial cell walls trigger a robust anti-infective immune response.Inspired by that,two kinds of chiral polypeptides,poly(L-phenylalanine)-block-poly(L-lysine)(PL-K)and poly(Lphenylalanine)-block-poly(D-lysine)(PD-K),were synthesized and used as nanoadjuvants of nanovaccines for cancer prevention and therapy.The amphiphilic polypeptides self-assembled into nanoparticles with a diameter of about 30 nm during ultrasonic-assisted dissolution in phosphate-buffered saline.The nanovaccines PL-K-OVA and PD-K-OVA were easily prepared by mixing solutions of PL-K or PD-K and the model antigen chicken ovalbumin(OVA),respectively,with loading efficiencies of almost 100%.Compared to PL-K-OVA,PD-K-OVA more robustly induced dendritic cell maturation,antigen cross-presentation,and adaptive immune response.More importantly,it effectively prevented and treated the OVA-expressed B16-OVA melanoma model.PD-K-OVA achieved a tumor inhibition rate of 94.9%and even 97.0%by combining with anti-PD-1 antibody.Therefore,the chiral polypeptide nanoparticles represent simple,efficient,and extensively applicable nanoadjuvants for various nanovaccines.

Development of stimuli responsive polymeric nanomedicines modulating tumor microenvironment for improved cancer therapy

The complexity of the tumor microenvironment(TME)severely hinders the therapeutic effects of various cancer treatment modalities.The TME differs from normal tissues owing to the presence of hypoxia,lowpH,and immunesuppressive characteristics.Modulation of the TME to reverse tumor growth equilibrium is considered an effective way to treat tumors.Recently,polymeric nanomedicines have been widely used in cancer therapy,because their synthesis can be controlled and they are highly modifiable,and have demonstrated great potential to remodel the TME.In this review,we outline the application of various stimuli responsive polymeric nanomedicines to modulate the TME,aiming to provide insights for the design of the next generation of polymeric nanomedicines and promote the development of polymeric nanomedicines for cancer therapy.