Enhanced cellular uptake of near-infrared triggered targeted nanoparticles by cell-penetrating peptide TAT for combined chemo/photothermal/photodynamic therapy

Small Extracellular Vesicles Derived from Altered Peptide Ligand-Loaded Dendritic Cell Act as A Therapeutic Vaccine for Spinal Cord Injury Through Eliciting CD4+ T cell-Mediated Neuroprotective Immunity

The balance among different CD4+ T cell subsets is crucial for repairing the injured spinal cord. Dendritic cell (DC)-derived small extracellular vesicles (DsEVs) effectively activate T-cell immunity. Altered peptide ligands (APLs), derived from myelin basic protein (MBP), have been shown to affect CD4+ T cell subsets and reduce neuroinflammation levels. However, the application of APLs is challenging because of their poor stability and associated side effects. Herein, it is demonstrate that DsEVs can act as carriers for APL MBP87-99 A91 (A91-DsEVs) to induce the activation of 2 helper T (Th2) and regulatory T (Treg) cells for spinal cord injury (SCI) in mice. These stimulated CD4+ T cells can efficiently "home" to the lesion area and establish a beneficial microenvironment through inducing the activation of M2 macrophages/microglia, inhibiting the expression of inflammatory cytokines, and increasing the release of neurotrophic factors. The microenvironment mediated by A91-DsEVs may enhance axon regrowth, protect neurons, and promote remyelination, which may support the recovery of motor function in the SCI model mice. In conclusion, using A91-DsEVs as a therapeutic vaccine may help induce neuroprotective immunity in the treatment of SCI.

Near-infrared photodynamic and photothermal co-therapy based on organic small molecular dyes

Near-infrared (NIR) organic small molecule dyes (OSMDs) are effective photothermal agents for photothermal therapy (PTT) due to their advantages of low cost and toxicity, good biodegradation, and strong NIR absorption over a wide wavelength range. Nevertheless, OSMDs have limited applicability in PTT due to their low photothermal conversion efficiency and inadequate destruction of tumor regions that are nonirradiated by NIR light. However, they can also act as photosensitizers (PSs) to produce reactive oxygen species (ROS), which can be further eradicated by using ROS-related therapies to address the above limitations of PTT. In this review, the synergistic mechanism, composition, and properties of photodynamic therapy (PDT)-PTT nanoplatforms were comprehensively discussed. In addition, some specific strategies for further improving the combined PTT and PDT based on OSMDs for cancer to completely eradicate cancer cells were outlined. These strategies include performing image-guided co-therapy, enhancing tumor infiltration, increasing H2O2 or O2 in the tumor microenvironment, and loading anticancer drugs onto nanoplatforms to enable combined therapy with phototherapy and chemotherapy. Meanwhile, the intriguing prospects and challenges of this treatment modality were also summarized with a focus on the future trends of its clinical application.

A combination of a cell penetrating peptide and a protein translation inhibitor kills metastatic breast cancer cells

Cell Penetrating Peptides (CPPs) are promising anticancer and antimicrobial drugs. We recently reported that a peptide derived from the human mitochondrial/ER membrane-anchored NEET protein, Nutrient Autophagy Factor 1 (NAF-1; NAF-144-67), selectively permeates and kills human metastatic epithelial breast cancer cells (MDA-MB-231), but not control epithelial cells. As cancer cells alter their phenotype during growth and metastasis, we tested whether NAF-144-67 would also be efficient in killing other human epithelial breast cancer cells that may have a different phenotype. Here we report that NAF-144-67 is efficient in killing BT-549, Hs 578T, MDA-MB-436, and MDA-MB-453 breast cancer cells, but that MDA-MB-157 cells are resistant to it. Upon closer examination, we found that MDA-MB-157 cells display a high content of intracellular vesicles and cellular protrusions, compared to MDA-MB-231 cells, that could protect them from NAF-144-67. Inhibiting the formation of intracellular vesicles and dynamics of cellular protrusions of MDA-MB-157 cells, using a protein translation inhibitor (the antibiotic Cycloheximide), rendered these cells highly susceptible to NAF-144-67, suggesting that under certain conditions, the killing effect of CPPs could be augmented when they are applied in combination with an antibiotic or chemotherapy agent. These findings could prove important for the treatment of metastatic cancers with CPPs and/or treatment combinations that include CPPs.

Conjugated Polymer Nanoparticles for Tumor Theranostics

Water-dispersible conjugated polymer nanoparticles (CPNs) have demonstrated great capabilities in biological applications, such as in vitro cell/subcellular imaging and biosensing, or in vivo tissue imaging and disease treatment. In this review, we summarized the recent advances of CPNs used for tumor imaging and treatment during the past five years. CPNs with different structures, which have been applied to in vivo solid tumor imaging (fluorescence, photoacoustic, and dual-modal) and treatment (phototherapy, drug carriers, and synergistic therapy), are discussed in detail. We also demonstrated the potential of CPNs as cancer theranostic nanoplatforms. Finally, we discussed current challenges and outlooks in this field.

Glutathione-triggered nanoplatform for chemodynamic/metal-ion therapy

The integration of metal-ion therapy and hydroxyl radical (˙OH)-mediated chemodynamic therapy (CDT) holds great potential for anticancer treatment with high specificity and efficiency. Herein, Ag nanoparticles (Ag NPs) were enveloped with Cu²⁺-based metal-organic frameworks (MOFs) and further decorated with hyaluronic acid (HA) to construct a glutathione (GSH)-activated nanoplatform (Ag@HKU-HA) for specific chemodynamic/metal-ion therapy. The obtained nanoplatform could avoid the premature leakage of Ag in circulation, but realize the release of Ag at the tumor site owing to the degradation of external MOFs triggered by Cu²⁺-reduced glutathione. The generated Cu⁺ could catalyze endogenous H₂O₂ to the highly toxic ˙OH by a Fenton-like reaction. Meanwhile, Ag NPs were oxidized to toxic Ag ions in the tumor environment. As expect, the effect of CDT combined with metal-ion therapy exhibited an excellent inhibition of tumor cells growth. Therefore, this nanoplatform may provide a promising strategy for on-demand site-specific cancer combination treatment.

Multi-functional polymeric micelles for chemotherapy-based combined cancer therapy

Currently, the therapeutic performance of traditional mono-chemotherapy on cancers remains unsatisfactory because of the tumor heterogeneity and multidrug resistance. In light of intricate tumor structures and distinct tumor microenvironments (TMEs), combinational therapeutic strategies with multiple anticancer drugs from different mechanisms can synergistically optimize the outcomes and concomitantly minimize the adverse effects during the therapy process. Extensive research on polymeric micelles (PMs) for biomedical applications has revealed the growing importance of nanomedicines for cancer therapy in the recent decade. Starting from traditional simple delivery systems, PMs have been extended to multi-faceted therapeutic strategies. Here we review and summarize the most recent advances in combinational therapy based on multifunctional PMs including a combination of multiple anticancer drugs, chemo-gene therapy, chemo-phototherapy and chemo-immunotherapy. The design approaches, action mechanisms and therapeutic applications of these nanodrugs are summarized. In addition, we highlight the opportunities and potential challenges associated with this promising field, which will provide new guidelines for advanced combinational cancer chemotherapy.

Tat-thioredoxin 1 reduces inflammation by inhibiting pro-inflammatory cytokines and modulating MAPK signaling

Thioredoxin 1 (Trx1) serves a central role in redox homeostasis. It is involved in numerous other processes, including oxidative stress and apoptosis. However, to the best of our knowledge, the role of Trx1 in inflammation remains to be explored. The present study investigated the function and mechanism of cell permeable fused Tat-Trx1 protein in macrophages and a mouse model. Transduction levels of Tat-Trx1 were determined via western blotting. Cellular distribution of transduced Tat-Trx1 was determined by fluorescence microscopy. 2',7'-Dichlorofluorescein diacetate and TUNEL staining were performed to determine the production of reactive oxygen species and DNA fragmentation. Protein and gene expression were measured by western blotting and reverse transcription-quantitative PCR (RT-qPCR), respectively. Effects of skin inflammation were determined using hematoxylin and eosin staining, changes in ear weight and ear thickness, and RT-qPCR in ear edema animal models. Transduced Tat-Trx1 inhibited lipopolysaccharide-induced cytotoxicity and activation of NF-κB, MAPK and Akt. Additionally, Tat-Trx1 markedly reduced the production of inducible nitric oxide synthase, cyclooxygenase-2, IL-1β, IL-6 and TNF-α in macrophages. In a 12-O-tetradecanoylphorbol-13-acetate-induced mouse model, Tat-Trx1 reduced inflammatory damage by inhibiting inflammatory mediator and cytokine production. Collectively, these results demonstrated that Tat-Trx1 could exert anti-inflammatory effects by inhibiting the production of pro-inflammatory mediators and cytokines and by modulating MAPK signaling. Therefore, Tat-Trx1 may be a useful therapeutic agent for diseases induced by inflammatory damage.

Engineered Exosomes-Based Photothermal Therapy with MRI/CT Imaging Guidance Enhances Anticancer Efficacy through Deep Tumor Nucleus Penetration

Exosomes, as natural nanovesicles, have become a spotlight in the field of cancer therapy due to their reduced immunogenicity and ability to overcome physiological barriers. However, the tumor targeting ability of exosomes needs to be improved before its actual application. Herein, a multiple targeted engineered exosomes nanoplatform was constructed through rare earth element Gd and Dy-doped and TAT peptide-modified carbon dots (CDs:Gd,Dy-TAT) encapsulated into RGD peptide engineered exosomes (Exo-RGD), which were used to enhance the effect of cancer imaging diagnosis and photothermal therapy. In vitro and in vivo experiments showed that the resulting CDs:Gd,Dy-TAT@Exo-RGD could effectively accumulate at cancer site with an increased concentration owing to the targeting peptides modification and exosomes encapsulation. The tumor therapy effects of mice treated with CDs:Gd,Dy-TAT@Exo-RGD were heightened compared with mice from the CDs:Gd,Dy control group. After intravenous injection of CDs:Gd,Dy-TAT@Exo-RGD into tumor-bearing mice, the temperature of tumors rose to above 50 °C under NIR irradiation and the localized hyperpyrexia induced by CDs could remarkably ablate tumors. The survival rate of the mice was 100% after 60 days. In addition, the CDs:Gd,Dy-TAT@Exo-RGD exhibited higher MRI/CT imaging contrast enhancement of tumor sites than that of CDs:Gd,Dy. Our study identified that engineered exosomes are a powerful tool for encapsulating multiple agents to enhance cancer theranostic efficiency and provide insight into precise personalized nanomedicine.

Radiodynamic Therapy Using TAT Peptide-Targeted Verteporfin-Encapsulated PLGA Nanoparticles

Radiodynamic therapy (RDT) is a recent extension of conventional photodynamic therapy, in which visible/near infrared light irradiation is replaced by a well-tolerated dose of high-energy X-rays. This enables greater tissue penetration to allow non-invasive treatment of large, deep-seated tumors. We report here the design and testing of a drug delivery system for RDT that is intended to enhance intra- or peri-nuclear localization of the photosensitizer, leading to DNA damage and resulting clonogenic cell kill. This comprises a photosensitizer (Verteporfin, VP) incorporated into poly (lactic-co-glycolic acid) nanoparticles (PLGA NPs) that are surface-functionalized with a cell-penetrating HIV trans-activator of transcription (TAT) peptide. In addition to a series of physical and photophysical characterization studies, cytotoxicity tests in pancreatic (PANC-1) cancer cells in vitro under 4 Gy X-ray exposure from a clinical 6 MV linear accelerator (LINAC) showed that TAT targeting of the nanoparticles markedly enhances the effectiveness of RDT treatment, particularly when assessed by a clonogenic, i.e., DNA damage-mediated, cell kill.

Specific modification and self-transport of porphyrins and their multi-mechanism cooperative antitumor studies

In order to reduce the toxicity and side effects of anti-tumor drugs and improve their therapeutic effect against cancer, photodynamic and chemical combination therapy has been exploited. However, the complicated preparation and metabolic toxicity of photosensitizer-loaded materials remain major obstacles for bioapplications. In this study, we designed and prepared a specific photosensitizer self-transporting drug-delivery system. First, 5,10,15,20-tetrakis(4-aminophenyl)-21H,23H-porphine (TAPP) was modified using specific molecules of d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) with a certain antitumor effect, to prepare a specific fluorescent amphiphilic system (TAPP-TPGS). Then, the drug-loaded fluorescence nanomicelle (TAPP-TPGS/PTX) was formed via self-assembly using the amphiphilic system and the anticancer drug paclitaxel (PTX). The carrier material could be used as a drug tracer and cancer therapy reagent to synergistically trace the chemotherapy drug and treat cancers. The biocompatibility and the enhanced antitumor effect of TAPP-TPGS/PTX were confirmed by in vitro and in vivo experiments. To detect the synergistic anticancer effect enhanced by TPGS, TAPP-mPEG synthesized with a similar method as TAPP-TPGS was used for a comparative analysis. The results showed that the excellent synergistic anticancer effect of the TAPP-TPGS/PTX was enhanced due to the introduction of TPGS. Thus, the specific porphyrin self-transporting nanomicelle is a very promising carrier material for applications in biomedicine.

Advances in Indocyanine Green-Based Codelivery Nanoplatforms for Combinatorial Therapy

Indocyanine green (ICG), a near-infrared (NIR) agent with an excellent imaging performance, has captivated enormous interest from researchers owing to its excellent therapeutic and imaging abilities. Although various nanoplatforms-based drug delivery systems (DDS) with the ability to overcome the clinical limitations of ICG has been reported, ICG-medicated conventional cancer diagnosis and photorelated therapies still lack in exhibiting the therapeutic efficacy, resulting in incomplete or partly tumor elimination. In the view of addressing these concerns, various DDSs have been engineered for the efficient codelivery of combined therapeutic agents with ICG, aiming to achieve promising therapeutic results due to multifunctional imaging-guided synergistic antitumor effects. In this article, we will systematically review currently available nanoplatforms based on polymers, inorganic, proteins, and metal-organic frameworks (MOFs), among others, for codelivery of ICG along with other therapeutic agents, providing a foundation for future clinical development of ICG. In addition, codelivery systems for ICG and different mechanism-based therapeutic agents will be illustrated. In summary, we conclude the review with the challenges and perspectives of ICG-based versatile nanoplatforms in detail.

Enhanced antitumor effect via amplified oxidative stress by near-infrared light-responsive and folate-targeted nanoplatform

The efficiency of producing hydroxyl radicals (·OH) from hydrogen peroxide (H₂O₂) catalyzed by different iron compounds have been explored extensively. Exclusively, ferrocenecarboxylic acid (FCA) showed the best catalyzed activity for ·OH generation. Then, we designed and prepared near-infrared (NIR) light-responsive and folate-targeted nanoplatform, which co-delivered FCA, cisplatin and indocyanine green (ICG) for improving antitumor therapy through amplified oxidative stress. The noteworthy observation is that under the irradiation of NIR light, the lecithin structure could able to depolymerize through the photothermal conversion mechanism of encapsulated dye ICG, which has achieved an intelligent release of drugs. In addition, the released cisplatin is not only fully effective to damage the DNA of cancer cells but it is able to induce the production of intracellular H₂O₂, which could further be catalyzed by FCA to generate toxic ·OH for oxidative damage via Fenton and Haber-Weiss reaction. This original strategy may provide an efficient way for improved chemotherapy via amplified oxidative stress.

A novel pH-responsive Fe-MOF system for enhanced cancer treatment mediated by the Fenton reaction

A novel pH-responsive Fe-MOF system for enhancing cancer treatment mediated by a Fenton reaction.

One-for-all intelligent core-shell nanoparticles for tumor-specific photothermal-chemodynamic synergistic therapy

Reasonable management of the one-for-all nanoplatform can facilitate improved cancer therapy. Here, the metal-organic frameworks (MOFs) based on iron(iii) carboxylate material (MIL-101-NH₂) were in situ decorated on stabilized polydopamine nanoparticles (PDANPs), which subsequently loaded glucose oxidase (GOx) via hyaluronic acid (HA) coating to structure the one-for-all intelligent core-shell nanoparticles (HG-MIL@PDANPs). Because of the inner PDANPs, the HG-MIL@PDANPs could realize near-infrared (NIR)-controllable site-specific photothermal therapy (PTT). Additionally, the core-shell nanoparticles exhibited a pH-triggered and NIR-reinforced release of Fe³⁺ and GOx owing to the controllable degradation of the outer shell. Hydroxyl radicals (˙OH) were produced for chemodynamic therapy (CDT) employing the Fe²⁺-driven Fenton reaction, which could be greatly promoted by Fe³⁺-involved glutathione (GSH) depletion and GOx-catalyzed acidity recovery and H₂O₂ self-sufficiency. Moreover, the HA ligand could enhance the tumor accumulation of the HG-MIL@PDANPs through the long blood circulation time and CD44-targeted cell recognition. The ingenious integration of PTT and CDT in one fully equipped system presented excellent synergistic antitumor efficiency in vitro and in vivo with favorable biosafety. The one-for-all intelligent core-shell nanoparticles with CD44 targeting provide a new avenue for engineering on-demand tumor-specific therapy.

Smart Porous Core-Shell Cuprous Oxide Nanocatalyst with High Biocompatibility for Acid-Triggered Chemo/Chemodynamic Synergistic Therapy

The rational integration of chemotherapy and hydroxyl radical (·OH)-mediated chemodynamic therapy (CDT) holds great potential for cancer treatment. Herein, a smart biocompatible nanocatalyst based on porous core-shell cuprous oxide nanocrystals (Cu₂ O-PEG (polyethylene glycol) NCs) is reported for acid-triggered chemo/chemodynamic synergistic therapy. The in situ formed high density of hydrophilic PEG outside greatly improves the stability and compatibility of NCs. The porosity of Cu₂ O-PEG NCs shows the admirable capacity of doxorubicin (DOX) loading (DOX@Cu₂ O-PEG NCs) and delivery. Excitingly, Cu (Cu^+/2+ ) and DOX can be controllably released from DOX@Cu₂ O-PEG NCs in a pH-responsive approach. The released Cu⁺ exerts Fenton-like catalytic activity to generate toxic ·OH from intracellular overexpressed hydrogen peroxide (H₂ O₂ ) for CDT via reactive oxygen species (ROS)-involved oxidative damage. Exactly, DOX can not only induce cell death for chemotherapy but also enhance CDT by self-supplying endogenous H₂ O₂ . After the intravenous injection, Cu₂ O-PEG NCs can effectively accumulate in tumor region via passive targeting improved by external high-density PEG shell. Additionally, the effect of boosted CDT combined with chemotherapy presents excellent in vivo antitumor ability without causing distinct systemic toxicity. It is believed that this smart nanocatalyst responding to the acidity provides a novel paradigm for site-specific cancer synergetic therapy.

A pH-activated autocatalytic nanoreactor for self-boosting Fenton-like chemodynamic therapy

The emergence of hydroxyl radical (˙OH)-mediated chemodynamic therapy (CDT) by the Fenton or Fenton-like reaction holds great potential for improving anticancer efficacy. Herein, an activatable autocatalytic nanoreactor (HT@GOx-DMONs) was developed for self-boosting Fenton-like CDT via decorating Cu²⁺-based metal-organic frameworks (MOFs) on glucose oxidase (GOx)-loaded dendritic mesoporous organosilica nanoparticles (DMONs) for the first time. The obtained nanoreactor could prevent the premature leakage of Cu²⁺ and GOx in neutral physiological environments conducted by the gatekeeper of growing carboxylate MOF (HKUST-1), but the explosive release of agents was realized due to the activated degradation of external HKUST-1 in acidic condition of endo/lysosomes, which thereby endowed this nanoreactor with the performance of pH-triggered ˙OH generation driven by Cu⁺-mediated autocatalytic Fenton-like reaction. Excitingly, Cu²⁺-induced glutathione (GSH) depletion and GOx-catalyzed H₂O₂ self-sufficiency unlocked by acid dramatically enhanced ˙OH generation. As expected, the effect of self-amplified CDT based on Cu²⁺-containing HT@GOx-DMONs presented wonderful in vitro toxicity and in vivo antitumor ability without leading to significant side-effects. The resulting nanoreactor with GSH consumption and H₂O₂ self-supply activated by acid may provide a promising paradigm for on-demand CDT.

Biodegradable Mesoporous Organosilica Nanosheets for Chemotherapy/Mild Thermotherapy of Cancer: Fast Internalization, High Cellular Uptake, and High Drug Loading

The choice of nanocarriers is crucial to fabricate ideal therapeutic nanoplatform in the treatment of cancer. Considering the advantages brought by the two-dimensional (2D) materials with atomic thickness in drug loading and cellular uptake, herein, novel 2D biodegradable mesoporous organosilica nanosheets (MONSs) are presented, and their application in chemotherapy/mild thermotherapy of cancer is studied by loading chemotherapy drug doxorubicin (DOX) and conjugating ultrasmall CuS nanoparticles. It is found that the loading of DOX in MONSs is as high as 859 μg/mg due to their large surface area and intermediate void structure. The release of DOX from MONSs is intelligently controlled by pH value, glutathione (GSH) concentration, and laser irradiation. Excitingly, in comparison with traditional spherical mesoporous organosilica nanoparticles, as-prepared MONSs not only show more rapid degradation but also exhibit faster internalization and higher cellular uptake efficiency due to their larger aspect ratios and unique cellular internalization approach of 2D materials. A mild thermotherapy induced by ultrasmall CuS nanoparticles can further promote the cellular uptake and improve chemotherapy efficacy. The in vitro and in vivo experimental results reveal that the theranostic nanoplatform based on degradable MONSs has excellent biocompatibility and anticancer effects. Therefore, MONSs are expected to be a competitive alternative to existing silica-based nanomaterials in antitumor treatment.

A novel versatile yolk-shell nanosystem based on NIR-elevated drug release and GSH depletion-enhanced Fenton-like reaction for synergistic cancer therapy

In this study, a versatile doxorubicin (DOX)-loaded yolk-shell nano-particles (HMCMD) assembled with manganese dioxide (MnO₂) as the core and copper sulfide (HMCuS) as the mesoporous (∼ 6.4 nm) shell, was designed and synthesized. The resulting HMCMD possess excellent photothermal conversion efficiency. The DOX release from the yolk-shell nanoparticles could be promoted by laser irradiation, which increased the chemotherapy of DOX. Meanwhile, Mn²⁺ could be released from the HMCMD through a redox reaction between MnO₂ and abundant glutathione (GSH) in tumor cells. The released Mn²⁺ could promote the decomposition of the intracellular hydrogen peroxide (H₂O₂) by Fenton-like reaction to generate the highly toxic hydroxyl radicals (·OH), thus exhibiting the effective chemodynamic therapy (CDT). Additionally, the efficiency of Mn²⁺-mediated CDT could be effectively enhanced by NIR irradiation. Further modification of polyethylene glycol (PEG) would improve the water solubility of the HMCMD to promote the uptake by MCF-7 cells. Hence, the HMCMD with synergistic effects of chemotherapy and chemodynamic/photothermal therapy would provide an alternative strategy in antitumor research.

Multimodal therapies: glucose oxidase-triggered tumor starvation-induced synergism with enhanced chemodynamic therapy and chemotherapy

A tumor microenvironment is distinct from normal tissue cells in characteristic physiochemical conditions, based on which we can design tumor-specific therapy modalities.

The antitumor activity of 4,4′-bipyridinium amphiphiles

The cell growth inhibition and apoptosis induction of 4,4′-bipyridinium amphiphiles.

The synthesis of an antifungal 1,2,4-triazole drug and the establishment of a drug delivery system based on zeolitic imidazolate frameworks

Schematic representation of a drug delivery system based on ZIF-8 for the therapy of invasive Candida albicans infections.