2 research outputs found
Immunogenic Cell Death Amplified by Co-localized Adjuvant Delivery for Cancer Immunotherapy
Despite
their potential, conventional whole-cell cancer vaccines
prepared by freeze–thawing or irradiation have shown limited
therapeutic efficacy in clinical trials. Recent studies have indicated
that cancer cells treated with certain chemotherapeutics, such as
mitoxantrone, can undergo immunogenic cell death (ICD) and initiate
antitumor immune responses. However, it remains unclear how to exploit
ICD for cancer immunotherapy. Here, we present a new material-based
strategy for converting immunogenically dying tumor cells into a powerful
platform for cancer vaccination and demonstrate their therapeutic
potential in murine models of melanoma and colon carcinoma. We have
generated immunogenically dying tumor cells surface-modified with
adjuvant-loaded nanoparticles. Dying tumor cells laden with adjuvant
nanodepots efficiently promote activation and antigen cross-presentation
by dendritic cells in vitro and elicit robust antigen-specific CD8α<sup>+</sup> T-cells in vivo. Furthermore, whole tumor-cell vaccination
combined with immune checkpoint blockade leads to complete tumor regression
in ∼78% of CT26 tumor-bearing mice and establishes long-term
immunity against tumor recurrence. Our strategy presented here may
open new doors to “personalized” cancer immunotherapy
tailored to individual patient’s tumor cells
Self-encapsulating Poly(lactic-<i>co</i>-glycolic acid) (PLGA) Microspheres for Intranasal Vaccine Delivery
Herein
we describe a formulation of self-encapsulating poly(lactic-<i>co</i>-glycolic acid) (PLGA) microspheres for vaccine delivery.
Self-healing encapsulation is a novel encapsulation method developed
by our group that enables the aqueous loading of large molecules into
premade PLGA microspheres. Calcium phosphate (CaHPO<sub>4</sub>) adjuvant
gel was incorporated into the microspheres as a protein-trapping agent
for improved encapsulation of antigen. Microspheres were found to
have a median size of 7.05 ± 0.31 μm, with a w/w loading
of 0.60 ± 0.05% of ovalbumin (OVA) model antigen. The formulation
demonstrated continuous release of OVA over a 49-day period. Released
OVA maintained its antigenicity over the measured period of >21
days
of release. C57BL/6 mice were immunized via the intranasal route with
prime and booster doses of OVA (10 μg) loaded into microspheres
or coadministered with cholera toxin B (CTB), the gold standard of
mucosal adjuvants. Microspheres generated a Th2-type response in both
serum and local mucosa, with IgG antibody responses approaching those
generated by CTB. The results suggest that this formulation of self-encapsulating
microspheres shows promise for further study as a vaccine delivery
system