Multifunctional nanoparticles precisely reprogram the tumor microenvironment and potentiate antitumor immunotherapy after near-infrared-II light-mediated photothermal therapy.

Mild-temperature photothermal therapy (mild PTT) is a safe and efficient antitumor therapy. However, mild PTT alone usually fails to activate the immune response and prevent tumor metastasis. Herein, a photothermal agent, copper sulfide@ovalbumin (CuS@OVA), with an effective PTT effect in the second near-infrared (NIR-II) window, is developed. CuS@OVA can optimize the tumor microenvironment (TME) and evoke an adaptive immune response. Copper ions are released in the acidic TME to promote the M1 polarization of tumor-associated macrophages. The model antigen OVA not only acts as a scaffold for nanoparticle growth but also promotes the maturation of dendritic cells, which primes naive T cells to stimulate adaptive immunity. CuS@OVA augments the antitumor efficiency of the immune checkpoint blockade (ICB) in vivo, which suppresses tumor growth and metastasis in a mouse melanoma model. The proposed therapeutic platform, CuS@OVA nanoparticles, may be a potential adjuvant for optimizing the TME and improving the efficiency of ICB as well as other antitumor immunotherapies. STATEMENT OF SIGNIFICANCE: Mild-temperature photothermal therapy (mild PTT) is a safe and efficient antitumor therapy, but usually fails to activate the immune response and prevent tumor metastasis. Herein, we develop a photothermal agent, copper sulfide@ovalbumin (CuS@OVA), with an excellent PTT effect in the second near-infrared (NIR-II) window. CuS@OVA can optimize the tumor microenvironment (TME) and evoke an adaptive immune response by promoting the M1 polarization of tumor-associated macrophages and the maturation of dendritic cells. CuS@OVA augments the antitumor efficiency of the immune checkpoint blockade (ICB) in vivo, suppressing tumor growth and metastasis. The platform may be a potential adjuvant for optimizing the TME and improving the efficiency of ICB as well as other antitumor immunotherapies.

Copper (α)/cis-platinum-loaded nanogels as an adjuvant potentiate disulfiram's antitumor efficacy.

Disulfiram (DSF) is nontoxic and exerts anticancer activity by forming highly toxic chelates via its metabolite diethyldithiocarbamate with transition metal ions. However, there are not enough such ions in the human body to maintain the therapeutic effect. Herein, we report nanogels that complex copper ions or cis-platinum (CDDP) for tumor metal delivery to potentiate DSF's antitumor efficacy. We synthesized zwitterionic poly[N-(3-(methacryloyloxy-2-hydroxy)propyl)]-N-methyl glycine (PGMA-SAR) capable of chelating copper ions or CDDP and formed nanogels with suitable size and zeta potential. The intravenously injected nanogels circulated long in the blood compartment and delivered a high concentration of metal ions to the tumor. Separately administered DSF could sequester the metal ions from the nanogels and form highly cytotoxic complexes with potent in vitro and in vivo anticancer activity. This study provides a new strategy to potentiate DSF in anticancer treatment.

Vanadyl nanocomplexes enhance photothermia-induced cancer immunotherapy to inhibit tumor metastasis and recurrence.

Conventional photothermal therapy (PTT) is insufficient to induce a strong and potent anti-tumor immune response. Herein, we present a vanadyl nanocomplex, which simultaneously serves as a photothermal agent (PTA) and an immunogenic cell death (ICD) inducer to enhance the anti-tumor immunity of PTT. The vanadyl nanocomplex (STVN) is constructed via facile one-step coordination assembly under ambient conditions. STVN not only has a strong and stable photothermal effect under near-infrared (NIR) irradiation, but also can cause severe endoplasmic reticulum (ER) stress by itself, leading to ICD and activating the systemic immune responses. In the absence of any adjuvants, NIR-irradiated STVN almost completely ablates primary tumors and simultaneously inhibits distant tumors in mice bearing bilateral melanoma. Meanwhile, the intratumorally injected STVN combined with NIR effectively suppressed melanoma lung metastasis as well as tumor recurrence, displaying that local STVN-mediated PTT could trigger a systemic anti-tumor immunity. Therefore, STVN, as a novel immunogenicity-enhanced PTA, affords a "one stone two birds" strategy for improved photothermia-induced cancer immunotherapy.

Progress and perspective of microneedle system for anti-cancer drug delivery.

Transdermal drug delivery exhibited encouraging prospects, especially through superficial drug administration routes. However, only a few limited lipophilic drug molecules could cross the skin barrier, those are with low molecular weight and rational Log P value. Microneedles (MNs) can overcome these limitations to deliver numerous drugs into the dermal layer by piercing the outermost skin layer of the body. In the case of superficial cancer treatments, topical drug administration faces severely low transfer efficiency, and systemic treatments are always associated with side effects and premature drug degradation. MN-based systems have achieved excellent technical capabilities and been tested for pre-clinical chemotherapy, photothermal therapy, photodynamic therapy, and immunotherapy. In this review, we will focus on the features, progress, and opportunities of MNs in the anticancer drug delivery system. Then, we will discuss the strategies and advantages in these works and summarize challenges, perspectives, and translational potential for future applications.

Assemblies of indocyanine green and chemotherapeutic drug to cure established tumors by synergistic chemo-photo therapy.

Indocyanine green (ICG), a safe and clinically approved near-infrared (NIR) dye, was recently explored as a potential photosensitizer due to its excellent photophysical properties. However, ICG tends to form aggregations in physiological solution, causing fluorescence quenching, fast blood clearance and thereby inefficient tumor accumulation. Herein, we report ICG-based nanodrug delivery systems formed by self-assembly of ICG and chemotherapeutic drugs without any excipients for combined chemo- and photo-therapy. Taking advantage of the amphiphilic aromatic structure, ICG readily bounded with hydrophobic aromatic drugs such as SN38 and formed well-dispersible nanoparticles, which reduced its aggregation-induced quenching and thus greatly improved its photodynamic efficiency. The loaded hydrophobic drugs elicited chemotherapy synergizing the photodynamic therapy, giving rise to much enhanced antitumor activity in vitro and in vivo against human glioblastoma cells and breast cancer cells upon NIR irradiation. The work demonstrates the fabrication of readily translational nanoformulations of hydrophobic drugs using amphiphilic drugs.

Integration of Polymerization and Biomineralization as a Strategy to Facilely Synthesize Nanotheranostic Agents.

Integration of biological macromolecules with inorganic materials via biomineralization has demonstrated great potential for development of nanotheranostic agents. To produce multifunctionality, integration of multiple components in the biomineralized theranostic agents is required; however, how to efficiently and reproducibly implement this is challenging. In this report, a universal biomineralization strategy is developed by incorporation of oxidization polymerization into albumin-templated biomineralization for facile synthesis of nanotheranostic agents. A series of biomineralized polymers and manganese dioxide hybrid nanoparticles (PMHNs) can be synthesized via the polymerization of various monomers, including dopamine (DA), epigallocatechin (EGC), pyrrole (PY), and diaminopyridine (DP), along with the reduction of KMnO4 and formation of manganese dioxide nanoparticles in albumin templates. These biomineralized PMHNs demonstrate ultrahigh MRI (longitudinal relaxivity up to 38 mM-1 s-1) and ultrasonic (US) imaging contrasting capabilities and have excellent photothermal therapy efficacy with complete ablation of orthotopic tumors. Moreover, these biomineralized hybrid nanoparticles can be effectively excreted through the kidneys, avoiding potential systemic toxicity. Thus, integration of polymerization into biomineralization presents a strategy for the fabrication of hybrid nanomaterials, allowing the production of multifunctional and biocompatible nanotheranostic agents via a facile one-pot method.