A targeting theranostics nanomedicine as an alternative approach for hyperthermia perfusion

Nanomedicines with Versatile GSH-Responsive Linkers for Cancer Theranostics

Glutathione (GSH)-responsive nanomedicines have generated significant interest in biochemistry, oncology, and material sciences due to their diverse applications, including chemical and biological sensors, diagnostics, and drug delivery systems. The effectiveness of these smart GSH-responsive nanomedicines depends critically on the choice of GSH-responsive linkers. Despite their crucial role, comprehensive reviews of GSH-responsive linkers are scarce, revealing a gap in the current literature. This review addresses this gap by systematically summarizing various GSH-responsive linkers and exploring their potential applications in cancer treatment. We provide an overview of the mechanisms of action of these linkers and their bioapplications, evaluating their advantages and limitations. The insights presented aim to guide the development of advanced GSH-responsive agents for cancer diagnosis and therapy.

Theranostic Fluorescent Probes

The ability to gain spatiotemporal information, and in some cases achieve spatiotemporal control, in the context of drug delivery makes theranostic fluorescent probes an attractive and intensely investigated research topic. This interest is reflected in the steep rise in publications on the topic that have appeared over the past decade. Theranostic fluorescent probes, in their various incarnations, generally comprise a fluorophore linked to a masked drug, in which the drug is released as the result of certain stimuli, with both intrinsic and extrinsic stimuli being reported. This release is then signaled by the emergence of a fluorescent signal. Importantly, the use of appropriate fluorophores has enabled not only this emerging fluorescence as a spatiotemporal marker for drug delivery but also has provided modalities useful in photodynamic, photothermal, and sonodynamic therapeutic applications. In this review we highlight recent work on theranostic fluorescent probes with a particular focus on probes that are activated in tumor microenvironments. We also summarize efforts to develop probes for other applications, such as neurodegenerative diseases and antibacterials. This review celebrates the diversity of designs reported to date, from discrete small-molecule systems to nanomaterials. Our aim is to provide insights into the potential clinical impact of this still-emerging research direction.

The application of nanoparticles-based ferroptosis, pyroptosis and autophagy in cancer immunotherapy

Immune checkpoint blockers (ICBs) have been applied for cancer therapy and achieved great success in the field of cancer immunotherapy. Nevertheless, the broad application of ICBs is limited by the low response rate. To address this issue, increasing studies have found that the induction of immunogenic cell death (ICD) in tumor cells is becoming an emerging therapeutic strategy in cancer treatment, not only straightly killing tumor cells but also enhancing dying cells immunogenicity and activating antitumor immunity. ICD is a generic term representing different cell death modes containing ferroptosis, pyroptosis, autophagy and apoptosis. Traditional chemotherapeutic agents usually inhibit tumor growth based on the apoptotic ICD, but most tumor cells are resistant to the apoptosis. Thus, the induction of non-apoptotic ICD is considered to be a more efficient approach for cancer therapy. In addition, due to the ineffective localization of ICD inducers, various types of nanomaterials have been being developed to achieve targeted delivery of therapeutic agents and improved immunotherapeutic efficiency. In this review, we briefly outline molecular mechanisms of ferroptosis, pyroptosis and autophagy, as well as their reciprocal interactions with antitumor immunity, and then summarize the current progress of ICD-induced nanoparticles based on different strategies and illustrate their applications in the cancer therapy.

Engineering prodrug nanomicelles as pyroptosis inducer for codelivery of PI3K/mTOR and CDK inhibitors to enhance antitumor immunity

Aberrant activation of oncogenic signaling pathways in tumors can promote resistance to the antitumor immune response. However, single blockade of these pathways is usually ineffective because of the complex crosstalk and feedback among oncogenic signaling pathways. The enhanced toxicity of free small molecule inhibitor combinations is considered an insurmountable barrier to their clinical applications. To circumvent this issue, we rationally designed an effective tumor microenvironment-activatable prodrug nanomicelle (PNM) for cancer therapy. PNM was engineered by integrating the PI3K/mTOR inhibitor PF-04691502 (PF) and the broad spectrum CDK inhibitor flavopiridol (Flav) into a single nanoplatform, which showed tumor-specific accumulation, activation and deep penetration in response to the high glutathione (GSH) tumoral microenvironment. The codelivery of PF and Flav could trigger gasdermin E (GSDME)-based immunogenic pyroptosis of tumor cells to elicit a robust antitumor immune response. Furthermore, the combination of PNM-induced immunogenic pyroptosis with anti-programmed cell death-1 (αPD-1) immunotherapy further boosted the antitumor effect and prolonged the survival time of mice. Collectively, these results indicated that the pyroptosis-induced nanoplatform codelivery of PI3K/mTOR and CDK inhibitors can reprogram the immunosuppressive tumor microenvironment and efficiently improve checkpoint blockade cancer immunotherapy.

Nanoparticles mediated tumor microenvironment modulation: current advances and applications

The tumor microenvironment (TME) plays a key role in cancer development and emergence of drug resistance. TME modulation has recently garnered attention as a potential approach for reprogramming the TME and resensitizing resistant neoplastic niches to existing cancer therapies such as immunotherapy or chemotherapy. Nano-based solutions have important advantages over traditional platform and can be specifically targeted and delivered to desired sites. This review explores novel nano-based approaches aimed at targeting and reprogramming aberrant TME components such as macrophages, fibroblasts, tumor vasculature, hypoxia and ROS pathways. We also discuss how nanoplatforms can be combined with existing anti-tumor regimens such as radiotherapy, immunotherapy, phototherapy or chemotherapy to enhance clinical outcomes in solid tumors.

A hybrid bacterium with tumor-associated macrophage polarization for enhanced photothermal-immunotherapy

Remodeling the tumor microenvironment through reprogramming tumor-associated macrophages (TAMs) and increasing the immunogenicity of tumors via immunogenic cell death (ICD) have been emerging as promising anticancer immunotherapy strategies. However, the heterogeneous distribution of TAMs in tumor tissues and the heterogeneity of the tumor cells make the immune activation challenging. To overcome these dilemmas, a hybrid bacterium with tumor targeting and penetration, TAM polarization, and photothermal conversion capabilities is developed for improving antitumor immunotherapy in vivo. The hybrid bacteria (B.b@QDs) are prepared by loading Ag₂S quantum dots (QDs) on the Bifidobacterium bifidum (B.b) through electrostatic interactions. The hybrid bacteria with hypoxia targeting ability can effectively accumulate and penetrate the tumor tissues, enabling the B.b to fully contact with the TAMs and mediate their polarization toward M1 phenotype to reverse the immunosuppressive tumor microenvironment. It also enables to overcome the intratumoral heterogeneity and obtain abundant tumor-associated antigens by coupling tumor penetration of the B.b with photothermal effect of the QDs, resulting in an enhanced immune effect. This strategy that combines B.b-triggered TAM polarization and QD-induced ICD achieved a remarkable inhibition of tumor growth in orthotopic breast cancer.

A Smart Theranostic Prodrug System Activated by Reactive Oxygen Species for Regional Chemotherapy of Metastatic Cancer

Metastatic cancer is difficult to cure because of its uncontrollable nature and side effects during treatment. We constructed a reactive oxygen species (ROS)-activated smart theranostic prodrug system based on an ROS active site linked with both a targeting group and an anticancer drug for efficient regional chemotherapy of metastatic cancers. The optimized prodrug (Bio-(8)-MB-CPT) with biotin as the targeting group displayed high sensitivity towards ROS and selectively targeting ability towards cervical cancer cells, showing highly efficient drug release (up to 92 %) in vitro. Bio-(8)-MB-CPT thus exerted strong toxicity towards cervical cancer cells, but unlike the parent drug (camptothecin), showed no toxicity towards normal cells. Moreover, the prodrug displayed significantly enhanced antitumor efficacy in vivo and eradicated the tumor with no obvious side effects (inhibition of the tumor reached up to 99.9 %).

An Integrated Fluorescent Probe for Ratiometric Detection of Glutathione in the Golgi Apparatus and Activated Organelle-Targeted Therapy

Cancer is a serious threat to human health, and there is an urgent need to develop new treatment methods to overcome it. Organelle targeting therapy, as a highly effective and less toxic side effect treatment strategy, has great research significance and development prospects. Being an essential organelle, the Golgi apparatus plays a particularly major role in the growth of cancer cells. Acting as an indispensable and highly expressed antioxidant in cancer cells, glutathione (GSH) also contributes greatly during the Golgi oxidative stress. Therefore, it counts for much to track the changes of GSH concentration in Golgi for monitoring the occurrence and development of tumor cells, and exploring Golgi-targeted therapy is also extremely important for effective treatment of cancer. In this work, we designed and synthesized a simple Golgi-targeting fluorescent probe GT-GSH for accurately detecting GSH. The probe GT-GSH reacting with GSH decomposes toxic substances to Golgi, thereby killing cancer cells. At the same time, the ratiometric fluorescent probe can detect the concentration changes of GSH in Golgi stress with high sensitivity and selectivity in living cells. Therefore, such a GSH-responsive fluorescent probe with a Golgi-targeted therapy effect gives a new method for accurate treatment of cancer.

A Versatile Theranostic Platform for Colorectal Cancer Peritoneal Metastases: Real-Time Tumor-Tracking and Photothermal-Enhanced Chemotherapy

A versatile tumor-targeting stimuli-responsive theranostic platform for peritoneal metastases of colorectal cancer is proposed in this work for tumor tracking and photothermal-enhanced chemotherapy. A quenched photosensitizer ("off" state) is developed and escorted into a tumor-targeting oxaliplatin-embedded micelle. Once reaching the tumor cell, the micelle is clasped to release free oxaliplatin, as well as the "off" photosensitizer, which is further activated ("turned-on") in the tumor reducing microenvironment to provide optical imaging and photothermal effect. The combined results from hyperthermia-enhanced chemotherapy, deep penetration, perfused O2 , and the leveraged GSH-ROS imbalance in tumor cells are achieved for improved antitumor efficacy and reduced systematic toxicity.

Targeted Delivery of Cabazitaxel Using Cyclic Cell-Penetrating Peptide and Biomarkers of Extracellular Matrix for Prostate and Breast Cancer Therapy

Targeted drug delivery for cancer therapy is an emerging area of research. Cancer cells overexpress certain biomarkers that can be exploited for their targeted therapy. Cyclic cell-penetrating peptides (cCPP) are increasingly assessed for intracellular cargo delivery in cancer cells. In this study, we have conjugated cabazitaxel (CBT) to the cCPP via an ester bond to assist CBT release in the tumor's acidic environment. Integrin targeting (RGDC, TP1) and extra domain B of fibronectin (EDB-Fn) targeting (CTVRTSAD, TP2) peptides were linked to the peptide-drug conjugate (cCPP-CBT) via a disulfide bond to provide targeting ability to the conjugates until they reach the tumor site. Conjugate 11 (TP1-cCPP-CBT) and conjugate 16 (TP2-cCPP-CBT) showed approximately 3-4-fold less antiproliferative activity on integrin and EDB-FN overexpressing cancer cell lines as compared to the CBT analogue used for comparison (CBT-GA, 5). Conjugates (11 and 16) were less toxic (31-34-fold less antiproliferative activity) to the normal human embryonic kidney (HEK-293) cells as compared to CBT. The flow cytometry and quantitative confocal microscopy data further confirm the selective efficacy of conjugates (TP1-cCPP-FAM (10) and TP1-cCPP-FAM (15)) toward biomarker overexpressing cancer cells. Furthermore, the stability and release studies of conjugate 11 revealed its therapeutic potential under different conditions, such as human plasma, different pHs, and redox conditions. This conjugation strategy was proven to enhance chemotherapeutics agents' efficacy and targeting and can be applied to other chemotherapeutic agents.

Multifunctional polymeric micellar nanomedicine in the diagnosis and treatment of cancer

Polymeric micelles are a prevalent topic of research for the past decade, especially concerning their fitting ability to deliver drug and diagnostic agents. This delivery system offers outstanding advantages, such as biocompatibility, high loading efficiency, water-solubility, and good stability in biological fluids, to name a few. The multifunctional polymeric micellar architect offers the added capability to adapt its surface to meet the looked-for clinical needs. This review cross-talks the recent reports, proof-of-concept studies, patents, and clinical trials that utilize polymeric micellar family architectures concerning cancer targeted delivery of anticancer drugs, gene therapeutics, and diagnostic agents. The manuscript also expounds on the underlying opportunities, allied challenges, and ways to resolve their bench-to-bedside translation for allied clinical applications.

Anti-Tumor Metastasis via Platelet Inhibitor Combined with Photothermal Therapy under Activatable Fluorescence/Magnetic Resonance Bimodal Imaging Guidance

Photothermal therapy (PTT) is a promising tumor therapy strategy; however, heterogeneous heat distribution over the tumor often exists, resulting in insufficient photothermal ablation and potential risk of cancer metastasis, which has been demonstrated to be associate with platelets. Herein, a near-infrared (NIR) photothermal agent of IR780 was conjugated with MRI agent of Gd-DOTA via a disulfide linkage (ICD-Gd), which was coassembly with lipid connecting tumor-homing pentapeptide CREKA (Cys-Arg-Glu-Lys-Ala) (DSPE-PEG-CREKA) to encapsulate a platelet inhibitor of ticagrelor (Tic), affording a multistimuli-responsive nanosystem (DPC@ICD-Gd-Tic). The nanosystem with completely quenching fluorescence could specifically target the tumor-associated platelets and showed pH/reduction/NIR light-responsive drug release, which simultaneously resulting in dis-assembly of nanoparticle and fluorescence recovery, enabling the drug delivery visualization in tumor in situ via activatable NIR fluorescence/MR bimodal imaging. Finally, DPC@ICD-Gd-Tic further integrated the photoinduced hyperthermia and platelet function inhibitor to achieve synergistic anticancer therapy, leading to ablation of primary tumor cells and effectively suppressed their distant metastasis. The number of lung metastases in 4T1 tumor bearing mice was reduced by about 90%, and the size of tumor was reduced by about 70%, while half of the mouse was completely cured by this smart nanosystem.

A magnetism/laser-auxiliary cascaded drug delivery to pulmonary carcinoma

Although high-efficiency targeted delivery is investigated for years, the efficiency of tumor targeting seems still a hard core to smash. To overcome this problem, we design a three-step delivery strategy based on streptavidin–biotin interaction with the help of c(RGDfK), magnetic fields and lasers. The ultrasmall superparamagnetic iron oxide nanoparticles (USIONPs) modified with c(RGDfK) and biotin are delivered at step 1, followed by streptavidin and the doxorubicin (Dox) loaded nanosystems conjugated with biotin at steps 2 and 3, respectively. The delivery systems were proved to be efficient on A549 cells. The co-localization of signal for each step revealed the targeting mechanism. The external magnetic field could further amplify the endocytosis of USPIONs based on c(RGDfK), and magnify the uptake distinctions among different test groups. Based on photoacoustic imaging, laser-heating treatment could enhance the permeability of tumor venous blood vessels and change the insufficient blood flow in cancer. Then, it was noticed in vivo that only three-step delivery with laser-heating and magnetic fields realized the highest tumor distribution of nanosystem. Finally, the magnetism/laser-auxiliary cascaded delivery exhibited the best antitumor efficacy. Generally, this study demonstrated the necessity of combining physical, biological and chemical means of targeting.

Dimeric prodrug-based nanomedicines for cancer therapy

With the rapid development of conjugation chemistry and biomedical nanotechnology, prodrug-based nanosystems (PNS) have emerged as promising drug delivery nanoplatforms. Dimeric prodrug, as an emerging branch of prodrug, has been widely investigated by covalently conjugating two same or different drug molecules. In recent years, great progress has been made in dimeric prodrug-based nanosystems (DPNS) for cancer therapy. Many advantages offered by DPNS have significantly facilitated the delivery efficiency of anticancer drugs, such as high drug loading capacity, favorable pharmacokinetics, tumor stimuli-sensitive drug release and facile combination theranostics. Given the rapid developments in this field, we here outline the latest updates of DPNS in cancer treatment, focusing on dimeric prodrug-encapsulated nanosystems, dimeric prodrug-nanoassemblies and tumor stimuli-responsive DPNS. Moreover, the design principle, advantages and challenges of DPNS for clinical cancer therapy are also highlighted.

Carry-On Nitric-Oxide Luggage for Enhanced Chemotherapeutic Efficacy

In this work, we proposed a carry-on nitric-oxide (NO) luggage strategy for enhanced chemotherapeutic efficacy. A stimuli-responsive NO-releasing polypeptide was prepared as the building block to assemble into a micelle as a chemodrug-carrier. The micelle was anchored with cRGD peptide with the aim of targeting to tumors' neoangiogenesis. In situ generation of NO at the tumor site can promote the neovascularization to recruit more chemotherapeutics. Besides, the introduced exogenous NO can directly induce apoptosis, synergistically with the chemotherapeutics. A specific near-infrared-region (NIR) NO-probe was also developed to be coloaded to the micelle to report the in situ NO-release. In vitro and in vivo experiments were performed to demonstrate the targeting capability, increased accumulation, real-time NO-release reporting phenomenon, improved antitumor efficacy, and favorable biosafety. Embedding NO into drug cargo as carry-on luggage for enhanced chemotherapeutic efficacy, hopefully, can cast new lights and build a basic principle in the future clinical translation of nanomedicines.

Ligand-Installed Nanocarriers toward Precision Therapy

Development of drug-delivery systems that selectively target neoplastic cells has been a major goal of nanomedicine. One major strategy for achieving this milestone is to install ligands on the surface of nanocarriers to enhance delivery to target tissues, as well as to enhance internalization of nanocarriers by target cells, which improves accuracy, efficacy, and ultimately enhances patient outcomes. Herein, recent advances regarding the development of ligand-installed nanocarriers are introduced and the effect of their design on biological performance is discussed. Besides academic achievements, progress on ligand-installed nanocarriers in clinical trials is presented, along with the challenges faced by these formulations. Lastly, the future perspectives of ligand-installed nanocarriers are discussed, with particular emphasis on their potential for emerging precision therapies.

Co-delivery of Cu(I) chelator and chemotherapeutics as a new strategy for tumor theranostic

Chelating Cu from tumors has been verified as an effective and promising strategy for cancer therapy through antiangiogenesis. However, systematic removal Cu by injecting with Cu chelators will result unavoidable side effects, since Cu is indispensable to the body. In this work, a micelle targeting to tumors' newborn vessels based on a polypeptide was developed to co-load DOX and Probe X, which can go through an "OFF-to-ON" procedure to report the Cu⁺-capture events in vivo in a real-time way by giving near infrared (NIR) fluorescence and photoacoustic signal. By co-delivering antiangiogenesis and chemotherapeutic reagents, the tumor can be significantly suppressed, meanwhile with a low systematic toxicity. Hopefully, this work can offer new insights in designing sophisticated antitumor strategy.

Principles and applications of nanomaterial-based hyperthermia in cancer therapy

Over the past few decades, hyperthermia therapy (HTT) has become one of the most promising strategies to treat cancer. HTT has been applied with nanotechnology to overcome drawbacks such as non-selectivity and invasiveness and to maximize therapeutic efficacy. The high temperature of HTT induces protein denaturation that leads to apoptosis or necrosis. It can also enhance the effects of other cancer therapies because heat-damaged tissues reduce radioresistance and help accumulate anticancer drugs. Gold nanoparticles and superparamagnetic iron oxide with different energy sources are commonly used as hyperthermia agents. New types of nanoparticles such as those whose surface is coated with several polymers and those modified with targeting moieties have been studied as novel HTT agents. In this review, we introduce principles and applications of nanotechnology-based HTT using gold nanoparticles and superparamagnetic iron oxide.

Theranostics system caged in human serum albumin as a therapy for breast tumors

Biomimetic materials are attracting increasing attention in the field of drug delivery due to their low immunogenicity, good biocompatibility and degradability.

pH- and enzyme-triggered drug release as an important process in the design of anti-tumor drug delivery systems

It is necessary to design a reasonable drug delivery system(DDS) for targeted release to overcome the potential toxicity and poor selectivity of anti-tumor drug. How a drug is released from a DDS is a critical issue that determines whether the DDS is designed successfully. We all know that the microenvironment of tumors is quite different from normal tissues, such as its acidic environment, different expression levels of some enzymes, etc. These features are widely used in the design of DDSs and play an important role in the drug release process in vivo. Numerous DDSs have been designed and synthesized. This article attention to how drugs are released from DDSs. We summarizes and classify the characteristic enzymes and chemical bonds used in the drug release process by browsing a large number of papers, and describes how they are applied in DDSs with specific examples. By understanding these acid-sensitive chemical bonds and over-expressed enzymes in tumors, different DDSs can be designed for different drug structures to solve specific problems of anti-tumor drugs.

Pre-blocked molecular shuttle as an in-situ real-time theranostics

Real-time monitor of drug-release from drug formulations in a noninvasive way can provide spatio-temporal information for drug activation and guide further clinical rational administration. In this work, a molecular shuttle, as a typical nanosized artificial molecular machine, was managed to act as a conceptually-new nanotheranostics for oxaliplatin. A post-recognition strategy was utilized, where a default supramolecular-dye couple was pre-blocked. The rational design, synthesis, characterization and proof-of-concept of this strategy were described in detail. The drug-release upon reducing environment can be translated into near-infrared (NIR) fluorescence signal (OFF-to-ON), allowing to track the drug-release procedure by multi-modal images including IVIS, FLECT and photoacoustic imaging. The versatile nanotheranostics system can target to triple negative breast tumor via conjugated F3 peptide, and show an improved anti-tumor efficacy with much lower side effect. The intelligent nanotheranostics system based on molecular shuttle provides new reference for precision medicine in preclinical trial and postclinical evaluation.