Therapeutic systems with site‐specific pharmaceutical activation hold great promise to enhance therapeutic efficacy while reducing systemic toxicity in cancer therapy. With operational flexibility, ...noninvasiveness, and high spatiotemporal resolution, photoactivatable nanomedicines have drawn growing attention. Distinct from traditional controlled release systems relying on the difference of biomarker concentrations between disease and healthy tissues, photoactivatable nanomedicines capitalize on the interaction between nanotransducers and light to either trigger photochemical reactions or generate reactive oxygen species (ROS) or heat effect to remotely induce pharmaceutical actions in living subjects. Herein, the recent advances in the development of photoactivatable protherapeutic nanoagents for oncology are summarized. The design strategies and therapeutic applications of these nanoagents are described. Representative examples of each type are discussed in terms of structure, photoactivation mechanism, and preclinical models. Last, potential challenges and perspectives to further develop photoactivatable protherapeutic nanoagents in cancer nanomedicine are discussed.
The recent progress of photoactivatable protherapeutic nanoagents in cancer therapy is reviewed. Protherapeutic nanoagents are defined as having the ability to respond to light, reactive oxygen species, or heat modulated by nanotransducers upon light irradiation, and subsequently activate the pharmaceutical actions. Such an in situ activation mechanism holds the potential to enhance therapeutic efficacy while reducing systemic toxicity of nanomedicines.
Insufficient tumor accumulation and distribution of photosensitizers as well as low antitumor immunity severely restrict the therapeutic efficacy of photothermal therapy (PTT). Cancer-associated ...fibroblasts (CAFs) play a key role in tumor extracellular matrix (ECM) remodeling and immune evasion. Reshaping tumor microenvironment via CAF regulation might provide a potential approach for complete tumor elimination in combination with PTT. Here, tumor cell-derived microparticles co-delivering calcipotriol and Indocyanine green (Cal/ICG@MPs) are developed to modulate CAFs for improved PTT efficacy. Cal/ICG@MPs efficiently target tumor tissues and regulate CAFs to reduce tumor ECM, resulting in enhanced tumor accumulation and penetration of ICG to generate strong PTT efficacy and activate CD8
T cell-mediated antitumor immunity. In addition, Cal/ICG@MPs-triggered CAF regulation enhances tumor infiltration of CD8
T cells and ameliorates CAF-induced antigen-mediated activation-induced cell death of tumor-specific CD8
T cells in response to PTT, eliciting long-term antitumor immune memory to inhibit tumor recurrence and metastasis. Our results support Cal/ICG@MPs as a promising drug to improve PTT efficacy in cancer treatment.
The main challenges for programmed cell death 1(PD-1)/PD-1 ligand (PD-L1) checkpoint blockade lie in a lack of sufficient T cell infiltration, tumor immunosuppressive microenvironment, and the ...inadequate tumor accumulation and penetration of anti-PD-1/PD-L1 antibody. Resetting tumor-associated macrophages (TAMs) is a promising strategy to enhance T-cell antitumor immunity and ameliorate tumor immunosuppression. Here, mannose-modified macrophage-derived microparticles (Man-MPs) loading metformin (Met@Man-MPs) are developed to efficiently target to M2-like TAMs to repolarize into M1-like phenotype. Met@Man-MPs-reset TAMs remodel the tumor immune microenvironment by increasing the recruitment of CD8
T cells into tumor tissues and decreasing immunosuppressive infiltration of myeloid-derived suppressor cells and regulatory T cells. More importantly, the collagen-degrading capacity of Man-MPs contributes to the infiltration of CD8
T cells into tumor interiors and enhances tumor accumulation and penetration of anti-PD-1 antibody. These unique features of Met@Man-MPs contribute to boost anti-PD-1 antibody therapy, improving anticancer efficacy and long-term memory immunity after combination treatment. Our results support Met@Man-MPs as a potential drug to improve tumor resistance to anti-PD-1 therapy.
The ultrahigh concentration of glutathione (GSH) inside tumors destroys reactive oxygen species (ROS)‐based therapy, improving the outcome of chemodynamic therapy (CDT)‐enhanced sonodynamic therapy ...(SDT) by depleting GSH is full of great challenge. Herein, PtCu3 nanocages are first reported as acting as a sonosensitizer with highly efficient ROS generation under ultrasound irradiation. In addition, PtCu3 nanocages can act as horseradish peroxidase‐like nanozymes, catalyzing the decomposition of H2O2 into •OH under acidic conditions for CDT. Surprisingly, PtCu3 nanocages can act as another kind of nanozyme, mimicking glutathione peroxidase (GSH‐Px), which plays an important role in accelerating GSH depletion by oxidizing molecules, further weakening the capacity of tumor cells scavenging ROS by GSH. Both in vitro and in vivo studies demonstrate that PtCu3 nanocages perform well in reducing GSH level for CDT‐enhanced SDT. Moreover, utilizing the high absorption in the near‐infrared region and strong X‐ray attenuation ability, the PtCu3 nanocages are able to conduct photoacoustic/computed tomography dual‐modal imaging‐guided combined cancer therapy. It is worth mentioning that PtCu3 nanocages cause minimal toxicity to normal tissues at therapeutic doses. This work highlights the use of PtCu3 nanocages for effective CDT‐enhanced SDT via GSH depletion.
This work presents tumor microenvironment‐responsive PtCu3 nanocages for glutathione depletion and chemodynamic therapy enhanced sonodynamic therapy. With their multimodal imaging functions of photoacoustic and computed tomography imaging, PtCu3 nanocages as theranostic agents may pave a new way for imaging‐guided cancer therapy.
Development of efficient therapeutic strategy to incorporate ultrasound (US)-triggered sonodynamic therapy (SDT) and ferroptosis is highly promising in cancer therapy. However, the SDT efficacy is ...severely limited by the hypoxia and high glutathione (GSH) in the tumor microenvironment, and ferroptosis is highly associated with reactive oxygen species (ROS) and GSH depletion.
A manganese porphyrin-based metal-organic framework (Mn-MOF) was constructed as a nanosensitizer to self-supply oxygen (O
) and decrease GSH for enhanced SDT and ferroptosis.
and
analysis, including characterization, O
generation, GSH depletion, ROS generation, lipid peroxidation, antitumor efficacy and tumor immune microenvironment were systematically evaluated.
Mn-MOF exhibited catalase-like and GSH decreasing activity
. After efficient internalization into cancer cells, Mn-MOF persistently catalyzed tumor-overexpressed H
O
to
produce O
to relieve tumor hypoxia and decrease GSH and GPX4, which facilitated the formation of ROS and ferroptosis to kill cancer cells upon US irradiation in hypoxic tumors. Thus, strong anticancer and anti-metastatic activity was found in H22 and 4T1 tumor-bearing mice after a single administration of Mn-MOF upon a single US irradiation. In addition, Mn-MOF showed strong antitumor immunity and improved immunosuppressive microenvironment upon US irradiation by increasing the numbers of activated CD8
T cells and matured dendritic cells and decreaing the numbers of myeloid-derived suppressor cells in tumor tissues.
Mn-MOF holds great potential for hypoxic cancer therapy.
Poor water solubility for many drugs and drug candidates remains a major obstacle to their development and clinical application. Conventional formulations to improve solubility suffer from low ...bioavailability and poor pharmacokinetics, with some carriers rendering systemic toxicities (e.g. Cremophor
® EL). In this review, several major nanonization techniques that seek to overcome these limitations for drug solubilization are presented. Strategies including drug nanocrystals, nanoemulsions and polymeric micelles are reviewed. Finally, perspectives on existing challenges and future opportunities are highlighted.
Developing biomimetic nanoparticles without loss of the integrity of proteins remains a major challenge in cancer chemotherapy. Here, we develop a biocompatible tumor-cell-exocytosed ...exosome-biomimetic porous silicon nanoparticles (PSiNPs) as drug carrier for targeted cancer chemotherapy. Exosome-sheathed doxorubicin-loaded PSiNPs (DOX@E-PSiNPs), generated by exocytosis of the endocytosed DOX-loaded PSiNPs from tumor cells, exhibit enhanced tumor accumulation, extravasation from blood vessels and penetration into deep tumor parenchyma following intravenous administration. In addition, DOX@E-PSiNPs, regardless of their origin, possess significant cellular uptake and cytotoxicity in both bulk cancer cells and cancer stem cells (CSCs). These properties endow DOX@E-PSiNPs with great in vivo enrichment in total tumor cells and side population cells with features of CSCs, resulting in anticancer activity and CSCs reduction in subcutaneous, orthotopic and metastatic tumor models. These results provide a proof-of-concept for the use of exosome-biomimetic nanoparticles exocytosed from tumor cells as a promising drug carrier for efficient cancer chemotherapy.
One of the main challenges for immune checkpoint blockade antibodies lies in malignancies with limited T-cell responses or immunologically "cold" tumors. Inspired by the capability of fever-like heat ...in inducing an immune-favorable tumor microenvironment, mild photothermal therapy (PTT) is proposed to sensitize tumors to immune checkpoint inhibition and turn "cold" tumors "hot." Here we present a combined all-in-one and all-in-control strategy to realize a local symbiotic mild photothermal-assisted immunotherapy (SMPAI). We load both a near-infrared (NIR) photothermal agent IR820 and a programmed death-ligand 1 antibody (aPD-L1) into a lipid gel depot with a favorable property of thermally reversible gel-to-sol phase transition. Manually controlled NIR irradiation regulates the release of aPD-L1 and, more importantly, increases the recruitment of tumor-infiltrating lymphocytes and boosts T-cell activity against tumors. In vivo antitumor studies on 4T1 and B16F10 models demonstrate that SMPAI is an effective and promising strategy for treating "cold" tumors.
Ag2S nanoparticles are increasingly important in biomedicine, such as in cancer imaging. However, there has been only limited success in the exploration of theranostic Ag2S nanoparticles for ...photoinduced cancer imaging and simultaneous therapy. Here we report size-dependent Ag2S nanodots (NDs) with well-defined nanostructure as a theranostic agent for multimodal imaging and simultaneous photothermal therapy. The NDs are precisely synthesized through carefully controlled growth of Ag2S in hollow human serum albumin nanocages. These NDs produce effective fluorescence in second near-infrared (NIR-II) region, distinct photoacoustic intensity, and good photothermal conversion in a size-dependent manner under light irradiation, thereby generating sufficient in vivo fluorescence and photoacoustic signals as well as potent hyperthermia at tumors. Moreover, Ag2S NDs possess ideal resistance to photobleaching, effective cellular uptake, preferable tumor accumulation, and in vivo elimination, thus facilitating NIR-II fluorescence/photoacoustics imaging with both ultrasensitivity and microscopic spatial resolution and simultaneous photothermal tumor ablation. These findings provide insight into the clinical potential of Ag2S nanodots for cancer theranostics.
Developing novel approaches to reverse the drug resistance of tumor-repopulating cells （TRCs） or stem cell-like cancer cells is an urgent clinical need to improve outcomes of cancer patients. Here we ...show an innovative approach that reverses drug resistance of TRCs using tumor cell-derived microparficles （T-MPs） containing anti-tumor drugs. TRCs, by virtue of being more deformable than differentiated cancer cells, preferentially take up T-MPs that release anti-tumor drugs after entering cells, which in turn lead to death of TRCs. The underlying mechanisms include interfering with drug efflux and promoting nuclear entry of the drugs. Our findings demonstrate the importance of tu- mor cell softness in uptake of T-MPs and effectiveness of a novel approach in reversing drug resistance of TRCs with promising clinical applications.
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