Spatiotemporally Light-Activatable Platinum Nanocomplexes for Selective and Cooperative Cancer Therapy

Evaluating the efficacy of Rose Bengal-PVA combinations within PCL/PLA implants for sustained cancer treatment

The current investigation aims to address the limitations of conventional cancer therapy by developing an advanced, long-term drug delivery system using biocompatible Rose Bengal (RB)-loaded polyvinyl alcohol (PVA) matrices incorporated into 3D printed polycaprolactone (PCL) and polylactic acid (PLA) implants. The anticancer drug RB's high solubility and low lipophilicity require frequent and painful administration to the tumour site, limiting its clinical application. In this study, RB was encapsulated in a PVA (RB@PVA) matrix to overcome these challenges and achieve a localised and sustained drug release system within a biodegradable implant designed to be implanted near the tumour site. The RB@PVA matrix demonstrated an RB loading efficiency of 77.34 ± 1.53%, with complete RB release within 30 min. However, when integrated into implants, the system provided a sustained RB release of 75.84 ± 8.75% over 90 days. Cytotoxicity assays on PC-3 prostate cancer cells indicated an IC50 value of 1.19 µM for RB@PVA compared to 2.49 µM for free RB, effectively inhibiting cancer cell proliferation. This innovative drug delivery system, which incorporates a polymer matrix within an implantable device, represents a significant advancement in the sustained release of hydrosoluble drugs. It holds promise for reducing the frequency of drug administration, thereby improving patient compliance and translating experimental research into practical therapeutic applications.

Highly Efficient Photodynamic Hydrogel with AIE-Active Photosensitizers toward Methicillin-Resistant Staphylococcus aureus Ultrafast Imaging and Killing

Methicillin-resistant Staphylococcus aureus (MRSA) causes great health hazards to society because most antibiotics are ineffective. Photodynamic treatment (PDT) has been proposed to combat MRSA due to the advantage of imaging-guided no-drug resistance therapy. However, the traditional photosensitizers for PDT are limited by aggregation-caused quenching for imaging and low photodynamic antibacterial efficiency. In this work, we synthesize a new aggregation-induced emission (AIE) photosensitizer (APNO), which can ultrafast distinguish between Gram-positive and Gram-negative bacteria within 3 s by AIE-active photosensitizer imaging. Meanwhile, APNO can generate antibacterial reactive oxygen species under light irradiation, which holds potential for antibacterial PDT. Then, APNO is loaded by PHEAA hydrogel to obtain a highly efficient photodynamic hydrogel (APNO@gel). In vitro results show complete inhibition of MRSA by APNO@gel under lower-power light irradiation. Transcriptome analysis is performed to investigate antibacterial mechanism of APNO@gel. Most importantly, APNO@gel also exhibits significant inhibition and killing ability of MRSA in the MRSA wound infection model, which will further promote rapid wound healing. Therefore, the photodynamic hydrogel provides a promising strategy toward MRSA ultrafast imaging and killing.

Metal nanoparticles for cancer therapy: Precision targeting of DNA damage

Cancer, a complex and heterogeneous disease, arises from genomic instability. Currently, DNA damage-based cancer treatments, including radiotherapy and chemotherapy, are employed in clinical practice. However, the efficacy and safety of these therapies are constrained by various factors, limiting their ability to meet current clinical demands. Metal nanoparticles present promising avenues for enhancing each critical aspect of DNA damage-based cancer therapy. Their customizable physicochemical properties enable the development of targeted and personalized treatment platforms. In this review, we delve into the design principles and optimization strategies of metal nanoparticles. We shed light on the limitations of DNA damage-based therapy while highlighting the diverse strategies made possible by metal nanoparticles. These encompass targeted drug delivery, inhibition of DNA repair mechanisms, induction of cell death, and the cascading immune response. Moreover, we explore the pivotal role of physicochemical factors such as nanoparticle size, stimuli-responsiveness, and surface modification in shaping metal nanoparticle platforms. Finally, we present insights into the challenges and future directions of metal nanoparticles in advancing DNA damage-based cancer therapy, paving the way for novel treatment paradigms.

Drug-Loaded Biomimetic Carriers for Non-Hodgkin's Lymphoma Therapy: Advances and Perspective

Chemotherapy remains the mainstay of treatment for the lymphoma patient population, despite its relatively poor therapeutic results, high toxicity, and low specificity. With the advancement of biotechnology, the significance of drug-loading biomimetic materials in the medical field has become increasingly evident, attracting extensive attention from the scientific community and the pharmaceutical industry. Given that they can cater to the particular requirements of lymphoma patients, drug-loading biomimetic materials have recently become a potent and promising delivery approach for various applications. This review mainly reviews the recent advancements in the treatment of tumors with biological drug carrier-loaded drugs, outlines the mechanisms of lymphoma development and the diverse treatment modalities currently available, and discusses the merits and limitations of biological drug carriers. What is more, the practical application of biocarriers in tumors is explored by providing examples, and the possibility of loading such organisms with antilymphoma drugs for the treatment of lymphoma is conceived.

Hydrophobicity-Adaptive Polymers Trigger Fission of Tumor-Cell-Derived Microparticles for Enhanced Anticancer Drug Delivery

Tumor-cell-derived microparticles (MPs) can function as anticancer drug-delivery carriers. However, short blood circulation time, large-size-induced insufficient tumor accumulation and penetration into tumor parenchyma, as well as limited cellular internalization by tumor cells and cancer stem cells (CSCs), and difficult intracellular drug release restrict the anticancer activity of tumor-cell-derived MP-based drug-delivery systems. In this work, hydrophobicity-adaptive polymers based on poly(N-isopropylacrylamide) are anchored to tumor-cell-derived MPs for enhanced delivery of the anticancer drug doxorubicin (DOX). The polymers are hydrophilic in blood to prolong the circulation time of DOX-loaded MPs (DOX@MPs), while rapidly switching to hydrophobic at the tumor acidic microenvironment. The hydrophobicity of polymers drives the fission of tumor-cell-derived MPs to form small vesicles, facilitating tumor accumulation, deep tumor penetration, and efficient internalization of DOX@MPs into tumor cells and CSCs. Subsequently, the hydrophobicity of polymers in acidic lysosomes further promotes DOX release to nuclei for strong cytotoxicity against tumor cells and CSCs. The work provides a facile and simple strategy for improved anticancer drug delivery of tumor-cell-derived MPs.

Bioavailability and translocation of platinum nanoparticles and platinum ions in rice (Oryza sativa L.): Nanoparticles biosynthesis and size-dependent transformation

Metal nanoparticles accumulation and bioavailability in plants raised much attention, specifically transformation and transportation of nanoparticles and their corresponding ions in plants are still unknown. In this work, rice seedlings were exposed to platinum nanoparticles (PtNPs) (with three sizes of 25, 50, and 70 nm) and Pt ions (with doses of 1, 2, and 5 mg/L) to investigate the influences of particle size and Pt form on bioavailability and translocation mechanism of metal nanoparticles. Results based on single particle ICP-MS (SP-ICP-MS) demonstrated the biosynthesis of PtNPs in Pt ions treated rice seedlings. The particle size ranges at 75-79.3 nm were detected in Pt ions exposed rice roots, and further migrated up to rice shoots at 21.7-44.3 nm. After exposed to PtNP-25, the particles could transfer to shoots with the original size distribution detected in roots, even with the PtNPs dose change. PtNP-50 and PtNP-70 translocated to shoots with the particle size increase. For the rice exposure with three dose levels, PtNP-70 had the highest number-based bioconcentration factors (NBCFs) in all Pt species, while Pt ions had the highest bioconcentration factors (BCFs), a range of 1.43-2.04. All PtNPs and Pt ions could be accumulated in rice plants and further transferred to shoots, and particle biosynthesis was proved through SP-ICP-MS. The finding could help us better understand the influence of particle size and form on the transformations of PtNPs in environment.

Self-Assembled Nanodelivery System with Rapamycin and Curcumin for Combined Photo-Chemotherapy of Breast Cancer

Nanodelivery systems combining photothermal therapy (PTT) and chemotherapy (CT), have been widely used to improve the efficacy and biosafety of chemotherapeutic agents in cancer. In this work, we constructed a self-assembled nanodelivery system, formed by the assembling of photosensitizer (IR820), rapamycin (RAPA), and curcumin (CUR) into IR820-RAPA/CUR NPs, to realize photothermal therapy and chemotherapy for breast cancer. The IR820-RAPA/CUR NPs displayed a regular sphere, with a narrow particle size distribution, a high drug loading capacity, and good stability and pH response. Compared with free RAPA or free CUR, the nanoparticles showed a superior inhibitory effect on 4T1 cells in vitro. The IR820-RAPA/CUR NP treatment displayed an enhanced inhibitory effect on tumor growth in 4T1 tumor-bearing mice, compared to free drugs in vivo. In addition, PTT could provide mild hyperthermia (46.0 °C) for 4T1 tumor-bearing mice, and basically achieve tumor ablation, which is beneficial to improving the efficacy of chemotherapeutic drugs and avoiding damage to the surrounding normal tissue. The self-assembled nanodelivery system provides a promising strategy for coordinating photothermal therapy and chemotherapy to treat breast cancer.

Radiofrequency-Activated Pyroptosis of Bi-Valent Gold Nanocluster for Cancer Immunotherapy

Pyroptosis is gasdermin-mediated programmed necrosis that exhibits promising potential application in cancer immunotherapy, and the main challenge lies in how to provoke specific pyroptosis of tumor cells. Here, biGC@PNA with a precisely stoichiometric ratio of Au(I) ion/Au(0) atom induced pyroptosis of tumor cells by its radiofrequency (RF)-heating effect. An in vitro/in vivo assay on 4T1 tumor cells indicates RF-activated pyroptosis of tumor cells elicits a robust ICD effect, enhancing the synergistic antitumor efficacy of biGC@PNA with decitabine, significantly suppressing tumor metastasis and relapse by provoking systemic antitumor immune responses. Utilizing RF-activated pyroptotic immune responses, biGC@PNA efficiently enhances the antitumor efficacy of αPD-1 immunotherapy under RF irradiation and provides a promising strategy for improving cancer immunotherapy by the noninvasive RF field with high clinical transformation potential.

A nuclease-mimetic platinum nanozyme induces concurrent DNA platination and oxidative cleavage to overcome cancer drug resistance

Platinum (Pt) resistance in cancer almost inevitably occurs during clinical Pt-based chemotherapy. The spontaneous nucleotide-excision repair of cancer cells is a representative process that leads to Pt resistance, which involves the local DNA bending to facilitate the recruitment of nucleotide-excision repair proteins and subsequent elimination of Pt-DNA adducts. By exploiting the structural vulnerability of this process, we herein report a nuclease-mimetic Pt nanozyme that can target cancer cell nuclei and induce concurrent DNA platination and oxidative cleavage to overcome Pt drug resistance. We show that the Pt nanozyme, unlike cisplatin and conventional Pt nanoparticles, specifically induces the nanozyme-catalyzed cleavage of the formed Pt-DNA adducts by generating in situ reactive oxygen species, which impairs the damage recognition factors-induced DNA bending prerequisite for nucleotide-excision repair. The recruitment of downstream effectors of nucleotide-excision repair to DNA lesion sites, including xeroderma pigmentosum groups A and F, is disrupted by the Pt nanozyme in cisplatin-resistant cancer cells, allowing excessive accumulation of the Pt-DNA adducts for highly efficient cancer therapy. Our study highlights the potential benefits of applying enzymatic activities to the use of the Pt nanomedicines, providing a paradigm shift in DNA damaging chemotherapy.

Advancing intestinal organoid technology to decipher nano-intestine interactions and treat intestinal disease

With research burgeoning in nanoscience and nanotechnology, there is an urgent need to develop new biological models that can simulate native structure, function, and genetic properties of tissues to evaluate the adverse or beneficial effects of nanomaterials on a host. Among the current biological models, three-dimensional (3D) organoids have developed as powerful tools in the study of nanomaterial-biology (nano-bio) interactions, since these models can overcome many of the limitations of cell and animal models. A deep understanding of organoid techniques will facilitate the development of more efficient nanomedicines and further the fields of tissue engineering and personalized medicine. Herein, we summarize the recent progress in intestinal organoids culture systems with a focus on our understanding of the nature and influencing factors of intestinal organoid growth. We also discuss biomimetic extracellular matrices (ECMs) coupled with nanotechnology. In particular, we analyze the application prospects for intestinal organoids in investigating nano-intestine interactions. By integrating nanotechnology and organoid technology, this recently developed model will fill the gaps left due to the deficiencies of traditional cell and animal models, thus accelerating both our understanding of intestine-related nanotoxicity and the development of nanomedicines.

The role of imaging in targeted delivery of nanomedicine for cancer therapy

Nanomedicines overcome the pharmacokinetic limitations of traditional drug formulations and have promising prospect in cancer treatment. However, nanomedicine delivery in vivo is still facing challenges from the complex physiological environment. For the purpose of effective tumor therapy, they should be designed to guarantee the five features principle, including long blood circulation, efficient tumor accumulation, deep matrix penetration, enhanced cell internalization and accurate drug release. To ensure the excellent performance of the designed nanomedicine, it would be better to monitor the drug delivery process as well as the therapeutic effects by real-time imaging. In this review, we summarize strategies in developing nanomedicines for efficiently meeting the five features of drug delivery, and the role of several imaging modalities (fluorescent imaging (FL), magnetic resonance imaging (MRI), computed tomography (CT), photoacoustic imaging (PAI), positron emission tomography (PET), and electron microscopy) in tracing drug delivery and therapeutic effect in vivo based on five features principle.

Confining isolated photosensitizers to relieve self-aggregation and potentiate photodynamic efficacy for synergistic cancer therapy

By quenching the electronic excited state, self-aggregation of photosensitizers deteriorates the photodynamic therapy (PDT) outcome. Previously reported strategies to mitigate aggregation-caused-quenching (ACQ) involve harsh conditions and tedious synthesis processes. Moreover, failure to tune the extent of photosensitizer aggregation on-demand usually leads to a sub-optimal PDT effect. Herein, a new insight into ACQ alleviation by precisely tailoring the aggregation extent of photosensitizers via the confinement effect is unraveled by concise and facile coordination co-assembly fabrication of Pt/TCPP NCPs. Optimized meso-tetra(4-carboxyphenyl)porphine (TCPP) aggregation extent was achieved by precisely regulating the PES/TCPP feeding ratio to 12, unleashing outstanding PDT efficacy for robustly synergistic cancer PDT/chemotherapy.

Platinum nanoplatforms: classic catalysts claiming a prominent role in cancer therapy

Platinum nanoparticles (Pt NPs) have a well-established role as a classic heterogeneous catalyst. Also, Pt has traditionally been employed as a component of organometallic drug formulations for chemotherapy. However, a new role in cancer therapy is emerging thanks to its outstanding catalytic properties, enabling novel approaches that are surveyed in this review. Herein, we critically discuss results already obtained and attempt to ascertain future perspectives for Pt NPs as catalysts able to modify key processes taking place in the tumour microenvironment (TME). In addition, we explore relevant parameters affecting the cytotoxicity, biodistribution and clearance of Pt nanosystems. We also analyze pros and cons in terms of biocompatibility and potential synergies that emerge from combining the catalytic capabilities of Pt with other agents such as co-catalysts, external energy sources (near-infrared light, X-ray, electric currents) and conventional therapies.

Extracellular vesicles for improved tumor accumulation and penetration

Extracellular vesicles (EVs), including microparticles and exosomes, have emerged as potential tools for tumor targeting delivery during the past years. Recently, mass of strategies are applied to assist EVs to accumulate and penetrate into deep tumor sites. In this review, EVs from different cells with unique innate characters and engineered approaches (e.g. chemical engineering, genetical engineering and biomimetic engineering) as drug delivery systems to enhance tumor accumulation and penetration are summarized. Meanwhile, efficient biological function modulation (e.g. extracellular matrix degradation, mechanical property regulation and transcytosis) is introduced to facilitate tumor accumulation and penetration of EVs. Finally, the prospects and challenges on further clinical applications of EVs are discussed.

Acid-Responsive Multifunctional Zeolitic Imidazolate Framework-8 (ZIF-8) Nanocomposites for Tumor Chemo-Photothermal Synergistic Therapy

Camptothecin (CPT), a broad-spectrum anticancer drug, has been extensively used clinically. However, its hydrophobic properties seriously hinder its antitumor therapeutic effect. Herein, we synthesized acid-degradable Fe₃O₄@poly(vinylpyrrolidone) (Fe₃O₄@PVP)/gold nanoclusters@zeolitic imidazolate framework-8 composite nanoparticles (ZIF-8CNPs) via a facile method and utilized them as carriers to efficiently load CPT. The excellent fluorescence properties of gold nanoclusters (AuNCs) and the photothermal properties of Fe₃O₄@poly(vinylpyrrolidone) (Fe₃O₄@PVP) endowed the nanocomposites with excellent cell imaging and photothermal functions. In addition, the surface modification of the composite nanoparticles with folic acid-grafted bovine serum albumin (FA-BSA) enables them to efficiently target tumor cells. Once FA-BSA/ZIF-8CNPs-CPT are taken up by tumor cells and irradiated with a near-infrared laser, the nanoparticles show a highly effective inhibitory effect against various tumor cells through a chemo-photothermal synergistic effect. Hence, it is conceivable that this acid-responsive multifunctional ZIF-8 nanocomposite has promising bioapplication prospects in cancer treatment.

Research Progress of Photothermal Nanomaterials in Multimodal Tumor Therapy

The aggressive growth of cancer cells brings extreme challenges to cancer therapy while triggering the exploration of the application of multimodal therapy methods. Multimodal tumor therapy based on photothermal nanomaterials is a new technology to realize tumor cell thermal ablation through near-infrared light irradiation with a specific wavelength, which has the advantages of high efficiency, less adverse reactions, and effective inhibition of tumor metastasis compared with traditional treatment methods such as surgical resection, chemotherapy, and radiotherapy. Photothermal nanomaterials have gained increasing interest due to their potential applications, remarkable properties, and advantages for tumor therapy. In this review, recent advances and the common applications of photothermal nanomaterials in multimodal tumor therapy are summarized, with a focus on the different types of photothermal nanomaterials and their application in multimodal tumor therapy. Moreover, the challenges and future applications have also been speculated.

Fabrication of injectable hydrogels from an anticancer peptide for local therapeutic delivery and synergistic photothermal-chemotherapy

The susceptibility of anticancer peptides to proteolytic degradation is often considered as a major weakness that limits systemic therapeutic applications. However, localized delivery of anticancer peptides via injectable hydrogels is expected to improve drug efficacy and reduce systemic toxicity. Herein, an injectable hydrogel with drug releasing properties, NIR responsiveness and pH sensitivity was developed from an anticancer peptide (KL), Fe³⁺ ions and protocatechualdehyde via dynamic and reversible interactions. Benefiting from the formation of Fe(III)-catechol complexes between Fe³⁺ ions and protocatechualdehyde within gel networks, the obtained hydrogel exhibited intrinsic NIR absorption properties for photothermal ablation of tumor cells, and remote light control of drug release. Besides, the pH-labile imine bonds between KL and protocatechualdehyde endowed the injectable gel with pH sensitivity for sustained release of KL under a mildly acidic environment, inducing membrane destabilization and facilitating the cell uptake of DOX for combinational chemotherapy. Both in vitro and in vivo experiments revealed that the injectable hydrogel exhibited a synergistic therapeutic effect on inhibiting tumor growth via combinational photothermal-chemotherapy. Therefore, this work provides a promising attempt to develop a therapeutic hydrogel from an anticancer peptide, which could work as a localized drug delivery platform for synergistic photothermal-chemotherapy.

A Tumor Microenvironments-Adapted Polypeptide Hydrogel/Nanogel Composite Boosts Antitumor Molecularly Targeted Inhibition and Immunoactivation

Various macro/microscopic biomaterials have been developed for controlled drug delivery in the combination therapy of malignancies. However, uncertain loading ratio, release sequence, and spatiotemporal distribution of drugs hinder their synergistic therapeutic effects and clinical applications. In this work, a tumor microenvironments-adapted composite consisting of a thermosensitive hydrogel and a reactive oxygen species (ROS)-responsive nanogel is developed for precisely sequential drug release to enhance molecularly targeted therapy and amplify immune activation. LY3200882 (LY), a selective transforming growth factor-β (TGF-β) inhibitor, is encapsulated in the ROS-responsive nanogel and dispersed uniformly with regorafenib (REG) in a thermosensitive hydrogel (Gel/(REG+NG/LY)). After in situ administration, REG is preferentially released from the hydrogel to inhibit tumor growth and promote ROS generation, which triggers the subsequent on-demand release of LY from the nanogel. LY contributes to preventing the epithelial-mesenchymal transition and immune escape of tumor cells induced by elevated TGF-β. In subcutaneous and orthotopic colorectal tumor bearing mouse models, Gel/(REG+NG/LY) effectively inhibits tumor growth and liver metastases by increasing the tumor infiltration of CD8⁺ T cells, reducing the recruitment of tumor-associated macrophages and myeloid-derived suppressor cells, and promoting the polarization of macrophages from M2 to M1 type, indicating the significant potential in improving the prognosis of advanced cancer patients.

A Photosensitizer Discretely Loaded Nanoaggregate with Robust Photodynamic Effect for Local Treatment Triggers Systemic Antitumor Responses

Photodynamic therapy (PDT), is a rising star for suppression of in situ and metastatic tumors, yet it is impeded by low ROS production and off-target phototoxicity. Herein, an aggregation degree editing strategy, inspired by gene editing, was accomplished by the coordination of an aggregation degree editor, p(MEO₂MA₁₆₀-co-OEGMA₄₀)-b-pSS₃₀ [POEGS; MEO₂MA = 2-(2-methoxyethoxy)ethyl methacrylate, OEGMA = oligo(ethylene glycol) methacrylate; pSS = poly(styrene sulfonate)] and indocyanine green (ICG) to nontoxic Mg²⁺, forming an ICG discretely loaded nanoaggregate (ICG-DNA). Optimization of the ICG aggregation degree [POEGS/ICG (P/I) = 6.55] was achieved by tuning the P/I ratio, alleviating aggregation-caused-quenching (ACQ) and photobleaching concurrently. The process boosts the PDT efficacy, spurring robust immunogenic cell death (ICD) and systemic antitumor immunity against primary and metastatic immunogenic "cold" 4T1 tumors via intratumoral administration. Moreover, the temperature-sensitive phase-transition property facilitates intratumoral long-term retention of ICG-DNA, reducing undesired phototoxicity to normal tissues; meanwhile, the photothermal-induced tumor oxygenation further leads to an augmented PDT outcome. Thus, this simple strategy improves PDT efficacy, boosting the singlet oxygen quantum yield (Φ_Δ)-dependent ICD effect and systemic antitumor responses via local treatment.

Rational Design of Nanotherapeutics Based on the Five Features Principle for Potent Elimination of Cancer Stem Cells

Cancer stem cells (CSCs), also known as tumor initiating cells or tumor repopulating cells, which comprise only a small fraction of tumor, have received tremendous attention during the past two decades, as they are considered as the ringleader for initiation and progression of tumors, therapy resistance, metastasis, and recurrence in the clinic. Hence, eradicating CSCs is critical for successful cancer treatment. To that end, various CSC-targeting therapeutic agents have been pursued. However, these CSC-specific drugs are ineffective toward bulk cancer cells. Furthermore, these anti-CSC drugs not only eradicate CSCs but also affect conventional stem cells in normal organs or tissues. By virtue of the enhanced permeability and retention (EPR) effect, nanomaterial drug delivery systems (NDDSs) passively accumulate in tumor tissues, thereby alleviating severe side effects toward normal viscera. NDDSs can be further functionalized with CSC-specific binding molecules to promote targeted drug delivery toward CSCs. Moreover, NDDSs have unique advantages in encapsulating CSC-specific drugs and cytotoxic agents, realizing synchronized killing of CSCs and bulk cancer cells both temporally and spatially. For these reasons, leveraging nanotherapeutic strategies to target CSCs has gained tremendous attention recently.Some ten years ago, we summarized five basic features of efficient nanotherapeutics (the five features principle), which consist of long circulation, tumor accumulation, deep penetration, cellular internalization, and drug release. Based on this design rationale, we constructed several NDDSs, including nanogels with adaptive hydrophobicity, CSC-derived microparticles with tailored softness, and tumor exosome sheathed porous silicon biomimetic nanoparticles, for targeted drug delivery to tumor. To our astonishment, these NDDSs that possess the five basic features achieve decent drug delivery efficiency toward not only bulk tumor cells but more importantly CSCs. Consequently, such nanotherapeutics as-designed based on the five features principle are potent in eradicating CSCs, even with only cytotoxic drugs, for instance, doxorubicin. Furthermore, commercialized nanomedicines, such as Doxil and Abraxane, can be endowed with these five basic features by hyperbaric oxygen therapy and therefore achieve outstanding drug delivery efficiency, potent CSC elimination, and efficient cancer therapy. These studies suggest that intractable CSCs can be tackled with a material-based approach, highlight the critical role of the five features principle in designing effective nanotherapeutics, and pinpoint the significance of drug delivery efficiency in eliminating CSCs and bulk cancer cells.

Tailoring Aggregation Extent of Photosensitizers to Boost Phototherapy Potency for Eliciting Systemic Antitumor Immunity

Phototherapy is effective for triggering the immunogenic cell death (ICD) effect. However, its efficacy is limited by low ¹ O₂  generation and photothermal conversion efficacy due to two irreconcilable obstacles, namely the aggregation-caused-quenching (ACQ) effect and photobleaching. In this work, a discretely integrated nanofabrication (DIN) platform (Pt-ICG/PES) is developed by facile coordination coassembly of cisplatin (Pt), photosensitizer molecules (indocyanine green (ICG)), and polymeric spacer (p(MEO₂ MA-co-OEGMA)-b-pSS (PES)). By controlling the ICG/PES feeding ratio, the aggregation of ICG can be easily tailored using PES as an isolator to balance the ACQ effect and photobleaching, thereby maximizing the phototherapy potency of Pt-ICG/PES. With the optimized ratio of each component, Pt-ICG/PES integrates the complementarity of photodynamic therapy, photothermal therapy, and chemotherapeutics to magnify the ICD effect, exerting a synergistic antitumor immunity-promoting effect. Additionally, temperature-sensitive PES enables photothermally guided drug delivery. In a tumor-bearing mouse model, Pt-ICG/PES elicits effective release of danger-associated molecular patterns, dendritic cell maturation, cytotoxic T lymphocytes activation, cytokine secretion, M2 macrophage repolarization, and distal tumor suppression, confirming the excellent in situ tumor ICD effect as well as robust systematic antitumor immunity. Ultimately, a versatile DIN strategy is developed to optimize the phototherapeutic efficacy for improving antitumor effects and strengthening systemic antitumor immunity.

A tyrosinase-responsive tumor-specific cascade amplification drug release system for melanoma therapy

Tumor-selective drug delivery could enhance anticancer efficacy and avoid drug side effects. However, because of tumor heterogeneity, current nanoparticle-based drug delivery systems rarely improve clinical outcomes significantly, commonly only reducing systemic toxicity. In this work, a new tumor-specific, tyrosinase-responsive cascade amplification release nanoparticle (TR-CARN) was developed to fulfill the needs for tumor-specific drug delivery and high efficacy cancer treatment. Tyrosinase (Tyr) is specifically expressed in melanomas and can catalyze acetaminophen (APAP) to increase reactive oxygen species (ROS). It was therefore utilized here to initiate the ROS amplification procedure. In TR-CARN, a ROS-responsive prodrug BDOX was loaded into an amphiphilic polymer, and APAP was linked to the polymer through a ROS-cleavable thioether bond. TR-CARN caused reduced side effects during the delivery because of the low toxicity of BDOX. Once TR-CARN entered into the tumor, endogenous ROS triggered initial APAP and BDOX release. Tyr-mediated ROS synthesis by APAP then accelerated APAP and BDOX release and toxification. Consequently, TR-CARN achieved melanoma-specific treatment of high efficacy through the cascade amplification strategy with enhanced biosafety.

Linear-Dendritic Polymer-Platinum Complexes Forming Well-Defined Nanocapsules for Acid-Responsive Drug Delivery

Polymeric nanocapsules hold considerable applications in cancer drug delivery, but the synthesis of well-defined nanocapsules with a tunable drug release property remains a significant challenge in fabrication. Herein, we demonstrate a supramolecular complexation strategy to assemble small molecular platinum (Pt) compounds into well-defined nanocapsules with high drug loading, acidity-sensitivity, and tunable Pt releasing profile. The design utilizes poly(ethylene glycol)-dendritic polylysine-G4/amides to complex with Pt compounds, forming stable nanocapsules with diameters approximately ∼20 nm and membrane thickness around several nanometers. The stability, drug content, and release profiles are tunable by tailoring the dendritic structure. The designated polymer-Pt nanocapsules, PEG-G4/MSA-Pt, showed sustained blood retention, preferential tumor accumulation, enhanced cellular uptake, lysosomal drug release, and nuclear delivery capability. PEG-G4/MSA-Pt showed enhanced antitumor efficacy compared to free cisplatin and other nanocapsules, which stopped the progression of both A549 cell xenografts and patient-derived xenografts (PDXs) of hepatocellular carcinoma on a mice tumor model. Thus, we believe this strategy is promising for developing Pt-based nanomedicine for cancer drug delivery.

Tumor-targeting inorganic nanomaterials synthesized by living cells

Inorganic nanomaterials (NMs) have shown potential application in tumor-targeting theranostics, owing to their unique physicochemical properties. Some living cells in nature can absorb surrounding ions in the environment and then convert them into nanomaterials after a series of intracellular/extracellular biochemical reactions. Inspired by that, a variety of living cells have been used as biofactories to produce metallic/metallic alloy NMs, metalloid NMs, oxide NMs and chalcogenide NMs, which are usually automatically capped with biomolecules originating from the living cells, benefitting their tumor-targeting applications. In this review, we summarize the biosynthesis of inorganic nanomaterials in different types of living cells including bacteria, fungi, plant cells and animal cells, accompanied by their application in tumor-targeting theranostics. The mechanisms involving inorganic-ion bioreduction and detoxification as well as biomineralization are emphasized. Based on the mechanisms, we describe the size and morphology control of the products via the modulation of precursor ion concentration, pH, temperature, and incubation time, as well as cell metabolism by a genetic engineering strategy. The strengths and weaknesses of these biosynthetic processes are compared in terms of the controllability, scalability and cooperativity during applications. Future research in this area will add to the diversity of available inorganic nanomaterials as well as their quality and biosafety.

A traceable, GSH/pH dual-responsive nanoparticles with spatiotemporally controlled multiple drugs release ability to enhance antitumor efficacy

Constructing highly efficient and multifunctional nanoparticles to overcome the multiple challenges of targeted drug delivery is a new strategy urgently needed in tumor therapy. Here, we synthesized pH-responsive prodrug (PEG_2K-NH-N-DOX), GSH-responsive prodrug (PEG_2K-S-S-CPT), folate-receptor targeting polymers (FA-PEG_2K-L8, FA-PEG_2K-TOS) and T1-enhanced magnetic resonance imaging contrast agents (Gd-DTPA-N16-16), used to encapsulate combrestatinA4 (CA4) to prepare multifunctional nanoparticles (FTDCAG NPs). Unlike other nanoparticles, FTDCAG NPs contains three drugs with the ability to control the release in time and space, which can maximize the effectiveness of precise cancer chemotherapy. We first confirmed that specific binding between FTDCAG NPs and overexpressed folate-receptor cells by flow cytometry and confocal laser scanning microscopy. We then investigated the spatiotemporally controlled release ability of FTDCAG NPs loaded with doxorubicin (DOX), CA4 and camptothecin (CPT). Relative to pH = 7.4, the release efficiency of CA4 in the pH = 6.5 increased by 63.4 %. The first released CA4 is able to destroy the angiogenesis and help tumor cells to be exposed to the remaining FTDCG NPs. After being internalized into the tumor cells, FTDCG NPs is disassembled and the CPT and DOX were released due to the increase of intracellular GSH concentration and the decrease of pH value. Besides, the relaxation time of FTDCAG NPs is 3.86 times that of clinical Gd-DTPA, and the in vitro and vivo T1-weighted imaging is brighter, which can be used to trace the nanoparticles by MRI. Therefore, FTDCAG NPs provide an efficient strategy for the design of multifunctional drug delivery systems for enhancing antitumor efficacy.

Assessment of the embolization effect of temperature-sensitive p(N-isopropylacrylamide-co-butyl methylacrylate) nanogels in the rabbit renal artery by CT perfusion and confirmed by macroscopic examination

Transcatheter embolization is an important treatment method in clinical therapy, and vascular embolization material plays a key role in embolization. The temperature-sensitive p(N-isopropylacrylamide-co-butyl methylacrylate) (PIB) nanogel is a novel embolic agent. To evaluate the feasibility of the nanogel as a blood vessel embolization agent, we aimed to assess the effect of embolization with PIB nanogels in the rabbit renal artery by non-invasive computed tomography (CT) perfusion, macroscopic and histological examination. Ten healthy adult Japanese rabbits were used to implement RAE of PIB nanogels in their right kidneys. CT perfusion scans were performed pre- and post-treatment at various time-points (1, 4, 8, and 12 weeks). Two rabbits were euthanized and histologically examined at each time-point, and the remaining rabbits were euthanized at 12 weeks after embolization. The RAE efficacy of the nanogels was further confirmed by macroscopic and histological examination. The renal volume and renal blood flow (BF) of the right kidney were significantly decreased post-treatment compared with those pre-treatment (volume: pre, 9278 ± 1736 mm³; post 1 week, 5155 ± 979 mm³, P < 0.0001; post 4 weeks, 3952 ± 846 mm³, P < 0.0001; post 8 weeks, 3226 ± 556 mm³, P < 0.0001; post 12 weeks, 2064 ± 507 mm³, P < 0.0001. BF: pre, 530.81 ± 51.50 ml/min/100 ml; post 1 week, 0 ml/min/100 ml, P < 0.0001; post 4 weeks, 0 ml/min/100 ml, P < 0.0001; post 8 weeks, 0 ml/min/100 ml, P < 0.0001; post 12 weeks, 0 ml/min/100 ml, P < 0.0001). No revascularization or collateral circulation was observed on histological examination during this period, and PIB nanogels were dispersed in all levels of the renal arteries. Twelve weeks after embolization, CT perfusion showed no BF in the right renal artery and renal tissue, a finding that was consistent with histological examination showing complete embolization of the right renal artery with a lack of formation of collateral vessels. The effect of embolization on PIB was adequate, with good dispersion and permanency, and could be evaluated by non-invasive and quantitative CT perfusion.

Noble Metal Nanomaterials for NIR-Triggered Photothermal Therapy in Cancer

It is of great significance to develop anticancer therapeutic agents or technologies with high degree of specificity and patient compliance, while low toxicity. The emerging photothermal therapy (PTT) has become a new and powerful therapeutic technology due to its noninvasiveness, high specificity, low side effects to normal tissues and strong anticancer efficacy. Noble metal nanomaterials possess strong surface plasmon resonance (SPR) effect and synthetic tunability, which make them facile and effective PTT agents with superior optical and photothermal characteristics, such as high absorption cross-section, incomparable optical-thermal conversion efficiency in the near infrared (NIR) region, as well as the potential of bioimaging. By incorporating with various functional reagents such as antibodies, peptides, biocompatible polymers, chemo-drug and immune factors, noble metal nanomaterials have presented strong potential in multifunctional cancer therapy. Herein, the recent development regarding the application of noble metal nanomaterials for NIR-triggered PTT in cancer treatment is summarized. A variety of studies with good therapeutic effects against cancer from impressive photothermal efficacy of noble metal nanomaterials are concluded. Intelligent nanoplatforms through ingenious fabrication showing potential of multifunctional PTT, combined with chemo-therapy, immunotherapy, photodynamic therapy (PDT), as well as simultaneous imaging modality are also demonstrated.

Boosting Nanomedicine Efficacy with Hyperbaric Oxygen Therapy

Nanomedicine has been a hot topic in the field of tumor therapy in the past few decades. Because of the enhanced permeability and retention effect (EPR effect), nanomedicine can passively yet selectively accumulate at tumor tissues. As a result, it can improve drug concentration in tumor tissues and reduce drug distribution in normal tissues, thereby contributing to enhanced antitumor effect and reduced adverse effects. However, the therapeutic efficacy of anticancer nanomedicine is not satisfactory in clinical settings. Therefore, how to improve the clinical therapeutic effect of nanomedicine has become an urgent problem. The grand challenges of nanomedicine lie in how to overcome various pathophysiological barriers and simultaneously kill cancer cells effectively in hypoxic tumor microenvironment (TME). To this end, the development of novel stimuli-responsive nanomedicine has become a new research hotspot. While a great deal of progress has been made in this direction and preclinical results report many different kinds of promising multifunctional smart nanomedicine, the design of these intelligent nanomedicines is often too complicated, the requirements for the preparation processes are strict, the cost is high, and the clinical translation is difficult. Thus, it is more practical to find solutions to promote the therapeutic efficacy of commercialized nanomedicines, for example, Doxil^®, Oncaspar^®, DaunoXome^®, Abraxane^®, to name a few. Increasing attention has been paid to the combination of modern advanced medical technology and nanomedicine for the treatment of various malignancies. Recently, we found that hyperbaric oxygen (HBO) therapy could enhance Doxil^® antitumor efficacy. Inspired by this study, we further carried out researches on the combination of HBO therapy with other nanomedicines for various cancer therapies, and revealed that HBO therapy could significantly boost antitumor efficacy of nanomedicine-mediated photodynamic therapy and photothermal therapy in different kinds of tumors, including hepatocellular carcinoma, breast cancer, and gliomas. Our results implicate that HBO therapy might be a universal strategy to boost therapeutic efficacy of nanomedicine against hypoxic solid malignancies.

Carrier-Free Platinum Nanomedicine for Targeted Cancer Therapy

Numerous nanomedicines have been developed to improve the efficiency and safety of conventional anticancer drugs; however, the complexities in carrier materials and functional integration make it challenging to promote these candidates for clinical translation. In this study, a facile method to prepare carrier-free anticancer nanodrug with inherent bone targeting and osteoclastogenesis inhibition capabilities is reported. Phytic acid, a naturally occurring and nontoxic product, is reacted with cisplatin to form uniform nanoparticles of different sizes. The prepared nanoparticles possess high drug loading and pH-responsive drug release behaviors. Phytic acid in the nanomedicine ensures high bone targeting and osteoclastogenesis inhibition, and the released platinum drugs triggered by tumor extracellular acidity eradicate tumor cells. The nanomedicine around 100 nm shows high anticancer activity and much reduced side effects in a subcutaneous breast cancer model when compared with cisplatin. In addition, it shows high accumulation at osteolytic lesions, and efficiently inhibits tumor growth and tumor-associated osteolysis in a bone metastatic breast cancer model. Here, a facile and efficient strategy to prepare carrier-free nanomedicines with high anticancer drug loading, inherent bone targeting, and osteoclast inhibitory activities for cancer therapy is provided.

Endogenous H2S-Activable Liposomal Nanoplatform for Synergistic Colorectal Tumor Ablation at Mild Apparent Temperature

Photoinduced hyperthermia possesses great potential in photothermal therapy and thermal-responsive chemotherapy of tumors. However, traditional thermal-triggered drug release requires high temperature, which results in unpleasant activation of thermal-induced cellular self-protection. In this work, a Cu-complex modified and drug-loaded liposomal nanoplatform was constructed for endogenous H₂S-activated synergistic ablation of colorectal tumors. In response to H₂S, the incorporated Cu-complex contributed to the formation of semiconductor CuS on the surface of the as-designed liposomal nanoplatform, which led to local heating under near-infrared (NIR) laser irradiation to achieve simultaneous photothermal therapy and drug release. It is noteworthy that although the drug release occurred at a mild apparent temperature, it was actually triggered by the high eigen temperature on the surface of the liposomal nanoplatform. Therefore, efficient and synergistic photothermal and chemotherapy was achieved under mild apparent temperatures. This work provides insights into achieving selective and bioactivated photothermal therapy and therefore thermal-controlled drug release without using excessive hyperthermia.

Design of light/ROS cascade-responsive tumor-recognizing nanotheranostics for spatiotemporally controlled drug release in locoregional photo-chemotherapy

Carrier-free nanotheranostics with high drug loading and no carrier-related toxicity are highly promising cancer therapy agents. However, the limited tumor accumulation and poorly controlled drug release of these nanotheranostics continue to be major challenges that restrict clinical applications. In this study, we develop a tumor-recognizing carrier-free nanotheranostic with light/reactive oxygen species (ROS) cascade-responsiveness for spatiotemporally selective photo-chemotherapy. The nanotheranostic is constructed by co-assembly of the indocyanine green (ICG) photosensitizer and the mannose-thioketal-doxorubicin conjugate (MAN-TK-DOX) (abbreviated as IMTD), efficiently preventing premature DOX leakage during blood circulation while reducing nonspecific damage to normal tissues/cells. Once accumulated in tumor tissues, IMTD rapidly diffuses into cancer cells via lectin receptors-mediated endocytosis. Photoacoustic/fluorescence-imaging-guided laser irradiation induces local hyperthermia and ROS generation in tumor cells, thereby promoting apoptosis. Together, the ICG-generated ROS and the endogenous ROS in cancer cells synergistically enhance DOX release, resulting in more efficient chemotherapeutic effects. The in vitro and in vivo results consistently demonstrate that IMTD achieves superior tumor accumulation, highly controllable drug release, and synergetic photo-chemotherapy. Therefore, the co-assembly of an ROS-sensitive targeting ligand-chemodrug conjugate and a photosensitizer could be used to develop spatiotemporally light-activatable nanotheranostics for precision cancer therapy. STATEMENT OF SIGNIFICANCE: Synergistic phototherapy and chemotherapy have been considered as a promising cancer treatment modality to maximize the therapeutic efficacy. Unfortunately, most nanodrugs consisting of chemotherapeutic drug and photosensitizer suffer from suboptimal tumor accumulation and poorly controlled drug release, which results in reduced therapeutic outcome. In this study, Mannose (MAN) was conjugated to the anticancer drug doxorubicin (DOX) by a ROS-sensitive thioketal linker (TK), the obtained amphiphilic MAN-TK-DOX could serve as an ideal self-carrier material to deliver photosensitizer, thus to achieve high-efficient tumor-targeting, spatiotemporal controlled drug release, and superior antitumor effect. We believe that the ROS-sensitive amphiphilic targeting ligand-chemodrug conjugate could be developed as a universal approach for designing tumor-targeted nanodrugs with precisely controlled drug release.

Point-of-care assay for drunken driving with Pd@Pt core-shell nanoparticles-decorated ploy(vinyl alcohol) aerogel assisted by portable pressure meter

Alcohol abuse causes health problems and security accidents. A reliable and sensitive detection system for alcohol has been an instinctive demand in law enforcement and forensic. More efforts are demanded in developing new sensing strategy preferably with portable and non-invasive traits for the pushforward of point-of-care (POC) device popularization.

Methods: We developed a POC diagnosis system for alcohol assay with the aid of alcohol oxidase (AOX) pre-joining in the system as well as Pd@Pt core-shell nanoparticles (abbreviated to Pd@Pt) that were decorated on ploy(vinyl alcohol) aerogel with amphiphilicity. Biological samples like saliva and whole blood can be absorbed by the aerogel in a quick process, in which the analyte would go through a transformation from alcohol, H₂O₂, to a final production of O₂, causing an analyte dose-dependent signal change in the commercial portable pressure meter. The cascade reactions are readily catalyzed by AOX and Pd@Pt, of which the latter one possesses excellent peroxidase-like activity.

Results: Our design has smartness embodied in the aerogel circumvents the interference from methanol which is more ready to be catalyzed by AOX. Under the optimal conditions, the limit of detection for alcohol was 0.50 mM in saliva, and is able to distinguish the driving under the influence (DUI) (1.74 mM in saliva) and driving while impaired (DWI) (6.95 mM in saliva) in the national standard of China.

Conclusion: Our proof-of-concept study provides the possibility for the establishment of POC device for alcohol and other target detection, not only owing to the sensing qualification but also thanks to the architecture of such sensor that has great flexibility by replacing the AOX with glucose oxidase (GOX), thenceforth realizing the accurate detection of glucose in 0.5% whole blood sample. With the advantages of easy accessibility and anti-interference ability, our sensor exhibits great potential for quantitative diagnostics in biological system.

Cellular microparticles for tumor targeting delivery: from bench to bedside

This feature article summarizes the progress in leveraging microparticles for tumor targeting delivery, from bench to bedside.

Photoactivated Trifunctional Platinum Nanobiotics for Precise Synergism of Multiple Antibacterial Modes

Integrating multiple strategies of antibacterial mechanisms into one has been proven to have tremendous promise for improving antimicrobial efficiency. Hence, dual-valent platinum nanoparticles (dvPtNPs) with a zero-valent platinum core (Pt⁰ ) and bi-valent platinum shell (Pt²⁺ ions), combining photothermal and photodynamic therapy, together with "chemotherapy," emerge as spatiotemporally light-activatable platinum nano-antibiotics. Under near-infrared (NIR) exposure, the multiple antibacterial modes of dvPtNPs are triggered. The Pt⁰ core reveals significant hyperthermia via effective photothermal conversion while an immediate release of chemotherapeutic Pt²⁺ ions occurs through hyperthermia-initiated destabilization of metallic interactions, together with reactive oxygen species (ROS) level increase, thereby resulting in synergistic antibacterial effects. The precise cooperative effects between photothermal, photodynamic, and Pt²⁺ antibacterial effects are achieved on both Gram-negative Escherichia coli and Gram-positive methicillin-resistant Staphylococcus aureus, where bacterial viability and colony-forming units are significantly reduced. Moreover, similar results are observed in mice subcutaneous abscess models. Significantly, after NIR treatment, dvPtNP exhibits a more robust bacteria-killing efficiency than other PtNP groups, owing to its integration of dramatic damage to the bacterial membrane and DNA, and alteration to ATP and ROS metabolism. This study broadens the avenues for designing and synthesizing antibacterial materials with higher efficiency.