Photoactivatable Prodrug-Backboned Polymeric Nanoparticles for Efficient Light-Controlled Gene Delivery and Synergistic Treatment of Platinum-Resistant Ovarian Cancer

A Nanoscale Trans-Platinum(II)-Based Supramolecular Coordination Self-Assembly with a Distinct Anticancer Mechanism

Drug resistance significantly hampers the clinical application of existing platinum-based anticancer drugs. New platinum medications that possess distinct mechanisms of action are highly desired for the treatment of Pt-resistant cancers. Herein, a nanoscale trans-platinum(II)-based supramolecular coordination self-assembly (Pt-TCPP-BA) is prepared via using trans-[PtCl2(pyridine)(NH3)] (transpyroplatin), tetracarboxylporphyrin (TCPP), and benzoic acid (BA) as building blocks to combat drug resistance in platinum-based chemotherapy. Mechanistic studies indicate that Pt-TCPP-BA shows a hydrogen-peroxide-responsive dissociation behavior along with the generation of bioactive trans-Pt(II) and TCPP-Pt species. Different from cisplatin, these degradation products interact with DNA via interstrand cross-links and small groove binding, and induce significant upregulation of cell-death-related proteins such as p53, cleaved caspase 3, p21, and phosphorylated H2A histone family member X in cisplatin-resistant cancer cells. As a result, Pt-TCPP-BA exhibits potent killing effects against Pt-resistant tumors both in vitro and in vivo. Overall, this work not only provides a new platinum drug for combating drug-resistant cancer but also offers a new paradigm for the development of platinum-based supramolecular anticancer drugs.

Nanodrugs based on co-delivery strategies to combat cisplatin resistance

Cisplatin (CDDP), as a broad-spectrum anticancer drug, is able to bind to DNA and inhibit cell division. Despite the widespread use of cisplatin since its discovery, cisplatin resistance developed during prolonged chemotherapy, similar to other small molecule chemotherapeutic agents, severely limits its clinical application. Cisplatin resistance in cancer cells is mainly caused by three reasons: DNA repair, decreased cisplatin uptake/increased efflux, and cisplatin inactivation. In earlier combination therapies, the emergence of multidrug resistance (MDR) in cancer cells prevented the achievement of the desired therapeutic effect even with the accurate combination of two chemotherapeutic drugs. Therefore, combination therapy using nanocarriers for co-delivery of drugs is considered to be ideal for alleviating cisplatin resistance and reducing cisplatin-related toxicity in cancer cells. This article provides an overview of the design of cisplatin nano-drugs used to combat cancer cell resistance, elucidates the mechanisms of action of cisplatin and the pathways through which cancer cells develop resistance, and finally discusses the design of drugs and related carriers that can synergistically reduce cancer resistance when combined with cisplatin.

Nanomaterials-Induced Redox Imbalance: Challenged and Opportunities for Nanomaterials in Cancer Therapy

Cancer cells typically display redox imbalance compared with normal cells due to increased metabolic rate, accumulated mitochondrial dysfunction, elevated cell signaling, and accelerated peroxisomal activities. This redox imbalance may regulate gene expression, alter protein stability, and modulate existing cellular programs, resulting in inefficient treatment modalities. Therapeutic strategies targeting intra- or extracellular redox states of cancer cells at varying state of progression may trigger programmed cell death if exceeded a certain threshold, enabling therapeutic selectivity and overcoming cancer resistance to radiotherapy and chemotherapy. Nanotechnology provides new opportunities for modulating redox state in cancer cells due to their excellent designability and high reactivity. Various nanomaterials are widely researched to enhance highly reactive substances (free radicals) production, disrupt the endogenous antioxidant defense systems, or both. Here, the physiological features of redox imbalance in cancer cells are described and the challenges in modulating redox state in cancer cells are illustrated. Then, nanomaterials that regulate redox imbalance are classified and elaborated upon based on their ability to target redox regulations. Finally, the future perspectives in this field are proposed. It is hoped this review provides guidance for the design of nanomaterials-based approaches involving modulating intra- or extracellular redox states for cancer therapy, especially for cancers resistant to radiotherapy or chemotherapy, etc.

An AIEgen and Iodine Double-Ornamented Platinum(II) Complex for Bimodal Imaging-Guided Chemo-Photodynamic Combination Therapy

Real-time biodistribution monitoring and enhancing the therapeutic efficacy of platinum(II)-based anticancer drugs are urgently required to elevate their clinical performance. Herein, a tetraphenylethene derivative (TP) with aggregation-induced emission (AIE) properties and an iodine atom are selected as ligands to endow platinum (II) complex TP-Pt-I with real-time in vivo self-tracking ability by fluorescence (FL) and computerized tomography (CT) imaging, and improved anticancer efficacy by the combination of chemotherapy and photodynamic therapy. Especially, benefiting from the formation of a donor-acceptor-donor structure between the AIE photosensitizer TP and Pt-I moiety, the heavy atom effects of Pt and I, and the presence of I, TP-Pt-I displayed red-shifted absorption and emission wavelengths, enhanced ROS generation efficiency, and improved CT imaging capacity compared with the pristine TP and the control agent TP-Pt-Cl. As a result, the enhanced intratumoral accumulation of TP-Pt-I loaded nanoparticles is readily revealed by dual-modal FL and CT imaging with high contrast. Meanwhile, the TP-Pt-I nanoparticles show significantly improved tumor growth-inhibiting effects on an MCF-7 xenograft murine model by combining the chemotherapeutic effects of platinum(II) and the photodynamic effects of TP. This self-tracking therapeutic complex thus provides a new strategy for improving the therapeutic outcomes of platinum(II)-based anticancer drugs.

Dynamic immuno-nanomedicines in oncology

Anti-cancer therapeutics have achieved significant advances due to the emergence of immunotherapies that rely on the identification of tumors by the patients' immune system and subsequent tumor eradication. However, tumor cells often escape immunity, leading to poor responsiveness and easy tolerance to immunotherapy. Thus, the potentiated anti-tumor immunity in patients resistant to immunotherapies remains a challenge. Reactive oxygen species-based dynamic nanotherapeutics are not new in the anti-tumor field, but their potential as immunomodulators has only been demonstrated in recent years. Dynamic nanotherapeutics can distinctly enhance anti-tumor immune response, which derives the concept of the dynamic immuno-nanomedicines (DINMs). This review describes the pivotal role of DINMs in cancer immunotherapy and provides an overview of the clinical realities of DINMs. The preclinical development of emerging DINMs is also outlined. Moreover, strategies to synergize the antitumor immunity by DINMs in combination with other immunologic agents are summarized. Last but not least, the challenges and opportunities related to DINMs-mediated immune responses are also discussed.

Multifunctional Nanoplatform for NIR-II Imaging-Guided Synergistic Oncotherapy

Tumors are a major public health issue of concern to humans, seriously threatening the safety of people's lives and property. With the increasing demand for early and accurate diagnosis and efficient treatment of tumors, noninvasive optical imaging (including fluorescence imaging and photoacoustic imaging) and tumor synergistic therapies (phototherapy synergistic with chemotherapy, phototherapy synergistic with immunotherapy, etc.) have received increasing attention. In particular, light in the near-infrared second region (NIR-II) has triggered great research interest due to its penetration depth, minimal tissue autofluorescence, and reduced tissue absorption and scattering. Nanomaterials with many advantages, such as high brightness, great photostability, tunable photophysical properties, and excellent biosafety offer unlimited possibilities and are being investigated for NIR-II tumor imaging-guided synergistic oncotherapy. In recent years, many researchers have tried various approaches to investigate nanomaterials, including gold nanomaterials, two-dimensional materials, metal sulfide oxides, polymers, carbon nanomaterials, NIR-II dyes, and other nanomaterials for tumor diagnostic and therapeutic integrated nanoplatform construction. In this paper, the application of multifunctional nanomaterials in tumor NIR-II imaging and collaborative therapy in the past three years is briefly reviewed, and the current research status is summarized and prospected, with a view to contributing to future tumor therapy.

Sequential Rocket-Mode Bioactivating Ticagrelor Prodrug Nanoplatform Combining Light-Switchable Diphtherin Transgene System for Breast Cancer Metastasis Inhibition

The increased risk of breast cancer metastasis is closely linked to the effects of platelets. Our previously light-switchable diphtheria toxin A fragment (DTA) gene system, known as the LightOn system, has demonstrated significant therapeutic potential; it lacks antimetastatic capabilities. In this study, we devised an innovative system by combining cell membrane fusion liposomes (CML) loaded with the light-switchable transgene DTA (pDTA) and a ticagrelor (Tig) prodrug. This innovative system, named the sequential rocket-mode bioactivating drug delivery system (pDTA-Tig@CML), aims to achieve targeted pDTA delivery while concurrently inhibiting platelet activity through the sequential release of Tig triggered by reactive oxygen species with the tumor microenvironment. In vitro investigations have indicated that pDTA-Tig@CML, with its ability to sequentially release Tig and pDTA, effectively suppresses platelet activity, resulting in improved therapeutic outcomes and the mitigation of platelet driven metastasis in breast cancer. Furthermore, pDTA-Tig@CML exhibits enhanced tumor aggregation and successfully restrains tumor growth and metastasis. It also reduces the levels of ADP, ATP, TGF-β, and P-selectin both in vitro and in vivo, underscoring the advantages of combining the bioactivating Tig prodrug nanoplatform with the LightOn system. Consequently, pDTA-Tig@CML emerges as a promising light-switchable DTA transgene system, offering a novel bioactivating prodrug platform for breast cancer treatment.

Cryo-shocked cancer cell microgels for tumor postoperative combination immunotherapy and tissue regeneration

Prevention of recurrence/metastasis and tissue regeneration are critical for post-surgery treatment of malignant tumors. Here, to address these needs, a novel type of microgel co-loading cryo-shocked cancer cells, immunoadjuvant, and immune checkpoint inhibitor is presented by microfluidic electrospray technology and liquid nitrogen treatment. Owing to the encapsulation of cryo-shocked cancer cells and immunoadjuvant, the microgels can recruit dendritic cells and activate them in situ, and evoke a robust immune response. Moreover, with the combination of the immune checkpoint inhibitor, the antitumor immune response is further enhanced by inhibiting the interaction of PD1 and PDL1. With this, the excellent anti-recurrence and anti-metastasis efficacy of the microgels are demonstrated in an orthotopic breast cancer mouse model. Besides, because of the excellent biocompatibility and appropriate degradation performance, the microgels can provide support for normal cell adhesion and growth, which is beneficial to tissue reconstruction. These properties indicate the great value of the cryo-shocked cancer cell microgels for efficient tumor postoperative combination immunotherapy and tissue regeneration.

Stimuli-Responsive Prodrug Chemistries for Cancer Therapy

Prodrugs are pharmacologically inactive, chemically modified derivatives of active drugs, which, following in vivo administration, are converted to the parent drugs through chemical or enzymatic cleavage. The prodrug approach holds tremendous potential to create the enhanced version of an existing pharmacological agent and leverage those improvements to augment the drug molecules' bioavailability, targeting ability, therapeutic efficacy, safety, and marketability. Especially in cancer therapy, prodrug application has received substantial attention. A prodrug can effectively broaden the therapeutic window of its parent drug by enhancing its release at targeted tumor sites while reducing its access to healthy cells. The spatiotemporally controlled release can be achieved by manipulating the chemical, physical, or biological stimuli present at the targeted tumor site. The critical strategy comprises drug-carrier linkages that respond to physiological or biochemical stimuli in the tumor milieu to yield the active drug form. This review will focus on the recent advancements in the development of various fluorophore-drug conjugates that are widely used for real-time monitoring of drug delivery. The use of different stimuli-cleavable linkers and the mechanisms of linker cleavage will be discussed. Finally, the review will conclude with a critical discussion of the prospects and challenges that might impede the future development of such prodrugs.

Near-infrared light-activated ROS generation using semiconducting polymer nanocatalysts for photodynamic-chemodynamic therapy

Chemodynamic therapy (CDT) is an emerging treatment strategy for cancer, but the low therapeutic efficacy and potential side effects still limit its applications. In this study, we report a semiconducting polymer nanocatalyst (PGFe) that can generate reactive oxygen species (ROS) only upon near-infrared (NIR) light-activation for photodynamic therapy (PDT)-synergized CDT. Such PGFe consists of a semiconducting polymer as a photosensitizer, iron oxide (Fe3O4) nanoparticles as CDT agents, and glucose oxidase (GOx), all of which are loaded into a singlet oxygen (1O2)-responsive nanocarrier. Under NIR laser irradiation, PGFe produces 1O2 through a photosensitizer-mediated PDT effect, and the produced 1O2 destroys the 1O2-responsive nanocarriers, leading to controlled releases of Fe3O4 nanoparticles and GOx. In a tumor microenvironment, GOx catalyzes glucose degradation to form hydrogen peroxide (H2O2), and thus the CDT effect of Fe3O4 nanoparticles is greatly improved. As such, an amplified ROS level in tumor cells is obtained by PGFe to induce cell death. PGFe can be utilized to treat subcutaneous 4T1 tumors, observably inhibiting the tumor growth and suppressing lung and liver metastasis. This study thus provides a NIR light-activated ROS generation strategy for precise and effective treatments of tumors.

Emerging platinum(IV) prodrug nanotherapeutics: A new epoch for platinum-based cancer therapy

Owing to the unique DNA damaging cytotoxicity, platinum (Pt)-based chemotherapy has long been the first-line choice for clinical oncology. Unfortunately, Pt drugs are restricted by the severe dose-dependent toxicity and drug resistance. Correspondingly, Pt(IV) prodrugs are developed with the aim to improve the antitumor performance of Pt drugs. However, as "free" molecules, Pt(IV) prodrugs are still subject to unsatisfactory in vivo destiny and antitumor efficacy. Recently, Pt(IV) prodrug nanotherapeutics, inheriting both the merits of Pt(IV) prodrugs and nanotherapeutics, have emerged and demonstrated the promise to address the underexploited dilemma of Pt-based cancer therapy. Herein, we summarize the latest fronts of emerging Pt(IV) prodrug nanotherapeutics. First, the basic outlines of Pt(IV) prodrug nanotherapeutics are overviewed. Afterwards, how versatile Pt(IV) prodrug nanotherapeutics overcome the multiple biological barriers of antitumor drug delivery is introduced in detail. Moreover, advanced combination therapies based on multimodal Pt(IV) prodrug nanotherapeutics are discussed with special emphasis on the synergistic mechanisms. Finally, prospects and challenges of Pt(IV) prodrug nanotherapeutics for future clinical translation are spotlighted.

Recent Advances of Platinum-Based Anticancer Complexes in Combinational Multimodal Therapy

Platinum drugs with manifest therapeutic effects are widely used, but their systemic toxicity and the drug resistance acquired by cancer cells limit their clinical applications. Thus, the exploration on appropriate methods and strategies to overcome the limitations of traditional platinum drugs becomes extremely necessary. Combination therapy of platinum drugs can inhibit tumor growth and metastasis in an additive or synergistic manner, and can potentially reduce the systemic toxicity of platinum drugs and overcome platinum-resistance. This review summarizes the various modalities and current progress in platinum-based combination therapy. The synthetic strategies and therapeutic effects of some platinum-based anticancer complexes in the combination of platinum drugs with gene editing, ROS-based therapy, thermal therapy, immunotherapy, biological modelling, photoactivation, supramolecular self-assembly and imaging modality are briefly described. Their potential challenges and prospects are also discussed. It is hoped that this review will inspire researchers to have more ideas for the future development of highly effective platinum-based anti-cancer complexes.

One pot preparation of muti-mode nanoplatform to combat ovarian cancer

Ovarian cancer is one of the most common gynecological cancers with high mortality rate. The battle against ovarian cancer usually impaired by the evolved multidrug resistance (MDR) phenotype as well as metastasis in cancers, which urgently call for the development of multi-mode strategies to overcome the MDR and reduce metastasis. Considering the good benefits of ferroptosis and photothermal therapy (PTT) in cancer management, we herein proposed a facile way to construct nanoparticle platform (Fe-Dox/PVP) composed of ferric chloride, doxorubicin (Dox) and polyvinyl pyrrolidone (PVP) for the multi-mode therapy of ovarian cancer using chemotherapy, ferroptosis and mild hypothermia PTT. Our results demonstrated that Fe-Dox/PVP with mild hypothermia was shown to have improved endosomal escape/drug delivery, enhanced ferroptosis induction and good tumor targeting effects. Most importantly, the integration of all three effects into one platform provided increased anti-metastasis effect and promising in vitro/in vivo anticancer performance with high biocompatibility. In this study, we offer a facile and robust way to prepare a multi-mode nanoplatform to combat ovarian cancer, which can be further extended for the management of many other cancers.

Advances and Challenges of Stimuli-Responsive Nucleic Acids Delivery System in Gene Therapy

Gene therapy has emerged as a powerful tool to treat various diseases, such as cardiovascular diseases, neurological diseases, ocular diseases and cancer diseases. In 2018, the FDA approved Patisiran (the siRNA therapeutic) for treating amyloidosis. Compared with traditional drugs, gene therapy can directly correct the disease-related genes at the genetic level, which guarantees a sustained effect. However, nucleic acids are unstable in circulation and have short half-lives. They cannot pass through biological membranes due to their high molecular weight and massive negative charges. To facilitate the delivery of nucleic acids, it is crucial to develop a suitable delivery strategy. The rapid development of delivery systems has brought light to the gene delivery field, which can overcome multiple extracellular and intracellular barriers that prevent the efficient delivery of nucleic acids. Moreover, the emergence of stimuli-responsive delivery systems has made it possible to control the release of nucleic acids in an intelligent manner and to precisely guide the therapeutic nucleic acids to the target site. Considering the unique properties of stimuli-responsive delivery systems, various stimuli-responsive nanocarriers have been developed. For example, taking advantage of the physiological variations of a tumor (pH, redox and enzymes), various biostimuli- or endogenous stimuli-responsive delivery systems have been fabricated to control the gene delivery processes in an intelligent manner. In addition, other external stimuli, such as light, magnetic fields and ultrasound, have also been employed to construct stimuli-responsive nanocarriers. Nevertheless, most stimuli-responsive delivery systems are in the preclinical stage, and some critical issues remain to be solved for advancing the clinical translation of these nanocarriers, such as the unsatisfactory transfection efficiency, safety issues, complexity of manufacturing and off-target effects. The purpose of this review is to elaborate the principles of stimuli-responsive nanocarriers and to emphasize the most influential advances of stimuli-responsive gene delivery systems. Current challenges of their clinical translation and corresponding solutions will also be highlighted, which will accelerate the translation of stimuli-responsive nanocarriers and advance the development of gene therapy.

Platinum Drug-Incorporating Polymeric Nanosystems for Precise Cancer Therapy

Platinum (Pt) drugs are widely used in clinic for cancer therapy, but their therapeutic outcomes are significantly compromised by severe side effects and acquired drug resistance. With the emerging immunotherapy and imaging-guided cancer therapy, precise delivery and release of Pt drugs have drawn great attention these days. The targeting delivery of Pt drugs can greatly increase the accumulation at tumor sites, which ultimately enhances antitumor efficacy. Further, with the combination of Pt drugs and other theranostic agents into one nanosystem, it not only possesses excellent synergistic efficacy but also achieves real-time monitoring. In this review, after the introduction of Pt drugs and their characteristics, the recent progress of polymeric nanosystems for efficient delivery of Pt drugs is summarized with an emphasis on multi-modal synergistic therapy and imaging-guided Pt-based cancer treatment. In the end, the conclusions and future perspectives of Pt-encapsulated nanosystems are given.

Reduction-responsive dextran-based Pt(IV) nano-prodrug showed a synergistic effect with doxorubicin for effective melanoma treatment

Melanoma, the deadliest skin cancer with high metastasis potential, has posed a great threat to human health. Accordingly, early efficient blocking of melanoma progression is vital in antitumor treatment. Herein, a reduction-responsive dextran-based Pt(IV) nano-prodrug (PDPN) was synthesized and used for doxorubicin (DOX) delivery to combat melanoma synergistically. First, PDPN was prepared by one-pot chemical coupling of carboxylated methoxy poly(ethylene glycol) (mPEG), dextran (Dex), and the crosslinking agent cisPt (IV)-COOH. PDPN had a spherical structure (R_h = 34 ± 11.3 nm). Then, DOX was encapsulated into the PDPN core to form DOX-loaded PDPN (PDPN-DOX). The obtained PDPN-DOX displayed reduction-responsive release of DOX and Pt, thus showing a synergistic anticancer effect in B16F10 cells (combination index, 0.46). Furthermore, in vivo experiments demonstrated that PDPN-DOX was effective for the synergistic treatment of subcutaneous melanoma. Collectively, the as-prepared PDPN could serve as a promising and versatile nano-prodrug carrier for the co-delivery of chemotherapeutics in tumor combination therapy.

Multifunctional Dendritic Au@SPP@DOX Nanoparticles Integrating Chemotherapy and Low-Dose Radiotherapy for Enhanced Anticancer Activity

Combined chemoradiotherapy can improve antitumor efficiency and reduce the side effects of monotherapy. In this study, we aimed to construct dendritic peptide-based multifunctional nanoparticles (Au@SPP@DOX) for a prolonged circulation time, enhanced cellular uptake, and targeted cancer therapy. Amphiphilic micelle PEG-polylysine-SA (SPP) is composed of polylysine combined with hydrophilic poly(ethylene glycol) (PEG) and hydrophobic stearic acid (SA). Doxorubicin (DOX) is loaded via the hydrophilic-hydrophobic interaction of SPP, and gold nanoparticles (AuNPs) are loaded via the electrostatic interaction with SPP. Au@SPP@DOX showed good biocompatibility and could be successfully accumulated at tumor sites through the enhanced permeability and retention (EPR) effect. Then, lysosomes could be ruptured due to the proton sponge effect. DOX became protonated in response to tumor extracellular acidity and was then released from SPP. Under the action of low-dose radiation, Au@SPP@DOX could promote the production of reactive oxygen species (ROS), increase mitochondrial dysfunction, block cell division, and ultimately promote tumor cell apoptosis to achieve a better antitumor effect. This study highlighted the benefit of chemoradiotherapy and suggested that Au@SPP@DOX might serve as a high-efficiency codelivery system for cancer combination therapy in the future.

Stimuli-Responsive Gene Delivery Nanocarriers for Cancer Therapy

Gene therapy provides a promising approach in treating cancers with high efficacy and selectivity and few adverse effects. Currently, the development of functional vectors with safety and effectiveness is the intense focus for improving the delivery of nucleic acid drugs for gene therapy. For this purpose, stimuli-responsive nanocarriers displayed strong potential in improving the overall efficiencies of gene therapy and reducing adverse effects via effective protection, prolonged blood circulation, specific tumor accumulation, and controlled release profile of nucleic acid drugs. Besides, synergistic therapy could be achieved when combined with other therapeutic regimens. This review summarizes recent advances in various stimuli-responsive nanocarriers for gene delivery. Particularly, the nanocarriers responding to endogenous stimuli including pH, reactive oxygen species, glutathione, and enzyme, etc., and exogenous stimuli including light, thermo, ultrasound, magnetic field, etc., are introduced. Finally, the future challenges and prospects of stimuli-responsive gene delivery nanocarriers toward potential clinical translation are well discussed. The major objective of this review is to present the biomedical potential of stimuli-responsive gene delivery nanocarriers for cancer therapy and provide guidance for developing novel nanoplatforms that are clinically applicable.

Dye-cored polylysine dendrimer as luminescent nanoplatform for imaging-guided anticancer drug delivery

Dendrimers have numerous applications in imaging and drug delivery. Designing a dendrimer diagnostic platform with a well-defined structure and controlled drug delivery is a formidable challenge. Here, we design dendritic polymer-platinum conjugates (G5-PEG-Pt) as pH-responsive nanovesicles for imaging-guided platinum drug delivery. The G5-PEG-Pt have a well-defined structure, intrinsically bright fluorescence, and acid-responsive drug release. The pH-responsive G5-PEG-Pt could rapidly release the platinum drug at acidic pH (5.0) than neutral pH (7.4). The G5-PEG-Pt could enter SKOV-3 human ovarian cancer cells by the endocytosis pathway and exhibited comparative cytotoxicity to free cisplatin. By virtue of the prolonged blood circulation time and the enhanced permeability and retention (EPR) effect, a 4.4-fold higher tumor platinum uptake than that of free cisplatin was achieved, potentially enhancing the therapeutic indexes of the platinum drug. Therefore, these pH-responsive platinum and fluorescent dendrimer conjugates are expected to be potent in vivo cancer optical imaging and therapy platforms.

Flexible Hollow Human Serum Albumin-Catalase Nanocapsules with High Accumulation and Uptake Ability for Enhanced Photodynamic Therapy

Introduction

Photodynamic therapy (PDT) has attracted increasing attention for tumor treatment because of its minimal invasiveness and specific spatiotemporal selectivity. However, insufficient tumor accumulation and low cellular uptake of photosensitizers limit its therapeutic efficacy.

Methods

In this study, flexible hollow human serum albumin/catalase nanocapsules (HSA/CATs) were created using a core-assisted protein-coating method and combined with the photosensitizer chlorin e6 (HSA/CAT@Ce6) for PDT.

Results and Discussion

Transmission electron microscopy (TEM) images demonstrate that HSA/CAT nanocapsules are flexible, with a uniform diameter (310 nm) and a well-defined hollow structure. Thanks to their flexibility, HSA/CAT@Ce6 nanocapsules show a higher cellular uptake than rigid nanoparticles. The nanocapsules effectively generate reactive oxygen species (ROS) in 4T1 cells because of their high cellular uptake and catalytic capacity, remarkably enhancing their in vitro PDT efficacy. In addition, the in vivo tumor accumulation of HSA/CAT@Ce6 nanocapsules is significantly larger than that of rigid nanoparticles and Ce6, meaning they are highly effective in tumor cell ablation. This demonstrates that our flexible nanoplatform holds great promise for enhancing PDT of tumor.

Copper-Nitrogen-Coordinated Carbon Dots: Transformable Phototheranostics from Precise PTT/PDT to Post-Treatment Imaging-Guided PDT for Residual Tumor Cells

Phototheranostics has attracted considerable attention in the fields of cancer diagnosis and treatment. However, the complete eradication of solid tumors using traditional phototheranostics is difficult because of the limited depth and range of laser irradiation. New phototheranostics enabling precise phototherapy and post-treatment imaging-guided programmed therapy for residual tumors is urgently required. Accordingly, this study developed a novel transformable phototheranostics by assembling hyaluronic acid (HA) with copper-nitrogen-coordinated carbon dots (CDs). In this transformable nanoplatform, named copper-nitrogen-CDs@HA, the HA component enables the specific targeting of cluster determinant (CD) 44-overexpressing tumor cells. In the tumor cells, redox glutathione converts Cu(II) (cupric ions) into Cu(I) (cuprous ions), which confers the novel transformable functionality to phototheranostics. Both in vitro and in vivo results reveal that the near-infrared-light-photoactivated Cu^II-N-CDs@HA could target CD44-overexpressing tumor cells for precise synergistic photothermal therapy and photodynamic therapy. This study is the first to observe that Cu^II-N-CDs@HA could escape from lysosomes and be transformed in situ into Cu^I-N-CDs@HA in tumor cells, with the d⁹ electronic configuration of Cu(II) changing to the d¹⁰ electronic configuration of Cu(I), which turns on their fluorescence and turns off their photothermal properties. This transformable phototheranostics could be used for post-treatment imaging-guided photodynamic therapy on residual tumor cells. Thus, the rationally designed copper-nitrogen-coordinated CDs offer a simple in situ transformation strategy for using multiple-stimulus-responsive precise phototheranostics in post-treatment monitoring of residual tumor cells and imaging-guided programmed therapy.

Pt(IV) prodrug initiated microparticles from microfluidics for tumor chemo-, photothermal and photodynamic combination therapy

Multimodal treatment modalities hold great potential for cancer therapy, thus current efforts are focusing on the development of more effective and practical synergistic therapeutic platforms. Herein, we present a novel trans, trans,trans-[Pt(N₃)₂(OH)₂(py)₂] (Pt(IV)) prodrug-initiated hydrogel microparticles (M_ICG-Pt) with indocyanine green (ICG) encapsulation by microfluidics for efficiently synergistic chemo-, photothermal (PTT) and photodynamic therapy (PDT). The employed Pt(IV) could not only serves as an initiator to generate azidyl radical (N₃ ^•) for photo-polymerization of methacrylate gelatin (GelMA) matrix, but also be reduced to high cytotoxic platinum(II) (Pt(II)) species for tumor chemotherapy. The laden ICG with highly photothermal heating ability and intrinsic reactive oxygen species (ROS) productivity endows the M_ICG-Pt with effective PTT/PDT performances upon near-infrared (NIR) light irradiation. In addition, benefiting from the production of oxygen during the photo-activation process of Pt(IV), the PDT efficacy of ICG-laden M_ICG-Pt could be further enhanced. Based on these advantages, we have demonstrated that the M_ICG-Pt could significantly eliminate cancer cells in vitro, and remarkably suppressed the tumor growth in vivo via synergistic chemotherapy, PTT, and PDT. These results indicate that such Pt(IV)-initiated hydrogel microparticles are ideal candidates of multimodal treatment platforms, holding great prospects for cancer therapy.

Current perspectives and trend of nanomedicine in cancer: A review and bibliometric analysis

The limitations of traditional cancer treatments are driving the creation and development of new nanomedicines. At present, with the rapid increase of research on nanomedicine in the field of cancer, there is a lack of intuitive analysis of the development trend, main authors and research hotspots of nanomedicine in the field of cancer, as well as detailed elaboration of possible research hotspots. In this review, data collected from the Web of Science Core Collection database between January 1st, 2000, and December 31st, 2021, were subjected to a bibliometric analysis. The co-authorship, co-citation, and co-occurrence of countries, institutions, authors, literature, and keywords in this subject were examined using VOSviewer, Citespace, and a well-known online bibliometrics platform. We collected 19,654 published papers, China produced the most publications (36.654%, 7204), followed by the United States (29.594%, 5777), and India (7.780%, 1529). An interesting fact is that, despite China having more publications than the United States, the United States still dominates this field, having the highest H-index and the most citations. Acs Nano, Nano Letters, and Biomaterials are the top three academic publications that publish articles on nanomedicine for cancer out of a total of 7580 academic journals. The most significant increases were shown for the keywords "cancer nanomedicine", "tumor microenvironment", "nanoparticles", "prodrug", "targeted nanomedicine", "combination", and "cancer immunotherapy" indicating the promising area of research. Meanwhile, the development prospects and challenges of nanomedicine in cancer are also discussed and provided some solutions to the major obstacles.

Dual-Cascade Responsive Nanoparticles Enhance Pancreatic Cancer Therapy by Eliminating Tumor-Resident Intracellular Bacteria

The limited drug penetration and robust bacteria-mediated drug inactivation in pancreatic cancer result in the failure of chemotherapy. To fight against these issues, a dual-cascade responsive nanoparticle (sNP@G/IR) that can sequentially trigger deep penetration, killing of intratumor bacteria, and controlled release of chemo-drug, is reported. sNP@G/IR consists of a hyaluronic acid (HA) shell and glutathione (GSH)-responsive polymer-core (NP@G/IR), that encapsulates gemcitabine (Gem) and photothermal agent (IR1048). The polymer core, as an antibiotic alternative, is tailored to exert optimal antibacterial activity and selectivity. sNP@G/IR actively homes in on the tumor due to the CD44 targeting of the HA shell, which is subsequently degraded by the hyaluronidase in the extracellular matrix. The resultant NP@G/IR in decreased size and reversed charge facilitates deep tumor penetration. After cellular endocytosis, the exposed guanidine on NP@G/IR kills intracellular bacteria through disrupting cell membranes. Intracellular GSH further triggers the controlled release of the cargo. Thus, the protected Gem eventually induces cell apoptosis. Under laser irradiation, the hyperthermia of IR1048 helps further elimination of tumors and bacteria. Moreover, sNP@G/IR activates immune response, thereby reinforcing anticancer capacity. Therefore, this dual-cascade responsive sNP@G/IR eliminates tumor-resident intracellular bacteria and augments drug delivery efficacy, providing a new avenue for improving cancer therapy.

Hierarchical Microparticles Delivering Oxaliplatin and NLG919 Nanoprodrugs for Local Chemo-immunotherapy

Chemo-immunotherapy shows promising antitumor therapeutic outcomes for many primary cancers. Research in this area has been focusing on developing an ideal formula that enables the potent efficacy of chemo-immunotherapy in combating various cancers with reduced systemic toxicity. Herein, we present novel hierarchical hydrogel microparticles (M_DDP) delivering oxaliplatin and NLG919 nanoprodrugs for local chemo-immunotherapy with desired features. The oxaliplatin prodrug and NLG919 were efficiently loaded in the dual-drug polymeric nanoparticles (DDP NPs), which were further encapsulated into a M_DDP by using microfluidic technology. When delivered to the tumor site, the DDP NPs will be sustainedly released from the M_DDP and retained locally to reduce systemic toxicity. After being endocytosed by cancer cells, the cytotoxic oxaliplatin and NLG919 could be successfully triggered to release from DDP NPs in a chain-shattering manner, leading to the immunogenic cell death (ICD) of tumor cells and the suppression of intratumoral immunosuppressive Tregs, respectively. With the assistance of an immune modulator, the chemotherapeutics-induced ICD could trigger robust systemic antitumor immune responses, presenting superior synergistic antitumor efficacies. Thus, the hierarchical microparticles could substantially inhibit the growth of mouse subcutaneous colorectal tumors, breast tumors, and colorectal tumors with large initial sizes via synergized chemo-immunotherapy, showing great potential in the practical clinical application of oncotherapy.

Degradable polyprodrugs: design and therapeutic efficiency

Prodrugs are developed to increase the therapeutic properties of drugs and reduce their side effects. Polyprodrugs emerged as highly efficient prodrugs produced by the polymerization of one or several drug monomers. Polyprodrugs can be gradually degraded to release therapeutic agents. The complete degradation of polyprodrugs is an important factor to guarantee the successful disposal of the drug delivery system from the body. The degradation of polyprodrugs and release rate of the drugs can be controlled by the type of covalent bonds linking the monomer drug units in the polymer structure. Therefore, various types of polyprodrugs have been developed based on polyesters, polyanhydrides, polycarbonates, polyurethanes, polyamides, polyketals, polymetallodrugs, polyphosphazenes, and polyimines. Furthermore, the presence of stimuli-responsive groups, such as redox-responsive linkages (disulfide, boronate ester, metal-complex, and oxalate), pH-responsive linkages (ester, imine, hydrazone, acetal, orthoester, P-O and P-N), light-responsive (metal-complex, o-nitrophenyl groups) and enzyme-responsive linkages (ester, peptides) allow for a selective degradation of the polymer backbone in targeted tumors. We envision that new strategies providing a more efficient synergistic therapy will be developed by combining polyprodrugs with gene delivery segments and targeting moieties.

Photochemical Internalization of siRNA for Cancer Therapy

Simple Summary

The objective of this review is to focus on the different nanovectors capable of transporting genetic material such as small-interfering RNA (siRNA) in order to block the expression of genes responsible for the development of cancer. Usually, these nanovectors are internalized by cancer cells via the endo-lysosomal pathway. To increase the lysosomal cargo escape, excitation using a lamp or a laser, can be applied to induce a more efficient leakage of siRNA to the cytoplasm, which is the site of action of the siRNA to block the translation of RNA into proteins. This is the mechanism of photochemical internalization.

Abstract

In the race to design ever more effective therapy with ever more focused and controlled actions, nanomedicine and phototherapy seem to be two allies of choice. Indeed, the use of nanovectors making it possible to transport and protect genetic material is becoming increasingly important. In addition, the use of a method allowing the release of genetic material in a controlled way in space and time is also a strategy increasingly studied thanks to the use of lasers. In parallel, the use of interfering RNA and, more particularly, of small-interfering RNA (siRNA) has demonstrated significant potential for gene therapy. In this review, we focused on the design of the different nanovectors capable of transporting siRNAs and releasing them so that they can turn off the expression of deregulated genes in cancers through controlled photoexcitation with high precision. This mechanism, called photochemical internalization (PCI), corresponds to the lysosomal leakage of the cargo (siRNA in this case) after destabilization of the lysosomal membrane under light excitation.

Engineered extracellular vesicles as intelligent nanosystems for next-generation nanomedicine

Extracellular vesicles (EVs), as natural carriers of bioactive cargo, have a unique micro/nanostructure, bioactive composition, and characteristic morphology, as well as fascinating physical, chemical and biochemical features, which have shown promising application in the treatment of a wide range of diseases. However, native EVs have limitations such as lack of or inefficient cell targeting, on-demand delivery, and therapeutic feedback. Recently, EVs have been engineered to contain an intelligent core, enabling them to (i) actively target sites of disease, (ii) respond to endogenous and/or exogenous signals, and (iii) provide treatment feedback for optimal function in the host. These advances pave the way for next-generation nanomedicine and offer promise for a revolution in drug delivery. Here, we summarise recent research on intelligent EVs and discuss the use of "intelligent core" based EV systems for the treatment of disease. We provide a critique about the construction and properties of intelligent EVs, and challenges in their commercialization. We compare the therapeutic potential of intelligent EVs to traditional nanomedicine and highlight key advantages for their clinical application. Collectively, this review aims to provide a new insight into the design of next-generation EV-based theranostic platforms for disease treatment.

Alantolactone-Loaded Pegylated Prodrug Nanocarriers for Synergistic Treatment of Cisplatin-Resistant Ovarian Cancer via Reactivating Mitochondrial Apoptotic Pathway

Ovarian cancer (OV) seriously damages women's health because of refractory OV and the development of platinum (Pt) resistance. New treatment strategies are urgently needed to deal with the treatment of cisplatin-resistant OV. Here, a reduction-sensitive pegylated Pt(IV) prodrug was synthesized by amidation of methoxy polyethylene glycol amine (PEG₇₅₀-NH₂) with monocarboxylic Pt(IV) prodrug (Pt(IV)-COOH). Then alantolactone (AL) loaded PEG-Pt(IV) nanocarriers (NP(Pt)@AL) were prepared. In the cisplatin-resistant model of OV, cancer cells actively ingest NP(Pt)@AL through endocytosis, and AL and Pt(II) were disintegrated and released under high intracellular reductant condition. The activity of thioredoxin reductase 1 (TrxR1) inhibited by AL and the adducts of Pt(II) with mitochondrial DNA (mDNA) can costimulate reactive oxygen species (ROS) and reactivate the mitochondrial pathway of apoptosis. Meanwhile, Pt(II) binds with nuclear DNA (nDNA) to jointly promote cell apoptosis. Both in vitro and in vivo results demonstrated that NP(Pt)@AL could effectively reverse the drug resistance and displayed excellent synergistic therapeutic efficacy on platinum-resistant OV with high safety. Therefore, reactivation of the mitochondrial pathway of apoptosis would be a potential strategy to improve the therapeutic effect of Pt-based chemotherapy and even reverse drug resistance.

Low-Intensity Light-Responsive Anticancer Activity of Platinum(II) Complex Nanocolloids on 2D and 3D In Vitro Cancer Cell Model

This study aimed to evaluate the therapeutic efficacy of low-intensity visible light responsive nanocolloids of a Pt-based drug using a 2D and three-dimensional (3D) in vitro cancer cell model. Biocompatible and biodegradable polymeric nanocolloids, obtained using the ultrasonication method coupled with Layer by Layer technology, were characterized in terms of size (100 ± 20 nm), physical stability, drug loading (78%), and photoactivation through spectroscopy studies. The in vitro biological effects were assessed in terms of efficacy, apoptosis induction, and DNA-Pt adducts formation. Biological experiments were performed both in dark and under visible light irradiation conditions, exploiting the complex photochemical properties. The light-stimuli responsive nanoformulation gave a significant enhancement in drug bioactivity. This allowed us to achieve satisfying results by using nanomolar drug concentration (50 nM), which was ineffective in darkness condition. Furthermore, our nanocolloids were validated in 3D in vitro spheroids using confocal microscopy and cytofluorimetric assay to compare their behavior on culture in 2D monolayers. The obtained results confirmed that these nanocolloids are promising tools for delivering Pt-based drugs.

pH-Responsive hyaluronic acid-cloaked polycation/gold nanohybrids for tumor-targeted synergistic photothermal/gene therapy

The combination of photothermal therapy (PTT) and gene therapy (GT) has attracted intense interest in cancer treatment. However, the lack of long circulation and active tumor targeting reduces the therapeutic efficacy of complementary PTT/GT. In this work, hyaluronic acid (HA)-cloaked gold nanorods-PGED (prepared by ring-opening of polyglycidyl methacrylate (PGMA) with ethylenediamine (ED))/pDNA (AP/pDNA-HA) complexes were prepared to achieve long circulation and tumor targeting for photoacoustic imaging (PAI)-guided synergistic PTT/GT. Gold nanorods endow the complexes with photothermal effect and PAI function. Benefiting from the HA cloak, the AP/pDNA-HA complexes exhibit excellent stability, biocompatibility, long circulation behavior and active targeting. In addition, the pH-responsive characteristic of the Schiff base bonds helps the AP/pDNA-HA complexes to effectively escape from the endosome/lysosome. The antioncogene p53 was employed to investigate the gene transfection efficiency of the delivery system both in vitro and in vivo. The superiority of synergistic PTT/GT is established in a mouse 4T1 breast tumor model. The current study provides a facile strategy for constructing multifunctional gene delivery systems with long circulation and tumor targeting features, which can achieve effective imaging-guided synergistic tumor treatment.

Verteporfin-loaded supramolecular micelles for enhanced cisplatin-based chemotherapy via autophagy inhibition

Cisplatin (CDDP) is one of the most successful chemotherapeutic agents for cancer therapy. However, CDDP can activate pro-survival autophagy, which inhibits the therapeutic efficacy of CDDP. Herein, autophagy inhibitor verteporfin (VTPF) is integrated into CDDP-conjugated micelles to address this issue. The CDDP-conjugated micelles are prepared by host-guest interaction of zwitterionic poly(2-(methacryloyloxy)ethyl phosphorylcholine)-co-poly(2-(methacryloyloxy)ethyl adamantane-1-carboxylate) (P(MPC-co-MAd)) and CDDP conjugated β-cyclodextrin (CD-CDDP). VTPF is then physically encapsulated into the supramolecular micelles by hydrophobic interaction. Due to the zwitterionic corona of the supramolecular micelles, the micelles are stable in different media. CDDP and VTPF could be released in a reductive environment. CDDP-activated autophagy could be inhibited by VTPF, which is fully characterized by western blot, fluorescence imaging, and transmission electron microscopy (TEM). Moreover, the outstanding therapeutic efficacy of CDDP and VTPF co-loaded micelles is validated both in vitro and in vivo. This research not only provides a new strategy to fabricate CDDP delivery systems by supramolecular self-assembly, but also presents an innovative way to enhance cisplatin-based chemotherapy via autophagy inhibition.

Targeted nanomedicine in cisplatin-based cancer therapeutics

Since its license in 1978, cisplatin has proved to be one of the most successful chemotherapeutic agents in the world. However, two acute challenges facing cisplatin, resistance and toxicity, have resulted in a bottleneck of clinical application. Targeted nanomedicine shows great promise in delivering cisplatin for maximizing efficacy while minimizing off-target toxicity. This article surveyed the recent progress and challenges of targeted nanomedicine in managing resistance and toxicity of cisplatin in both fundamental and clinical aspects. Particularly, we focused on three major mechanisms counteracting cisplatin sensitivity (decreased intracellular accumulation, increased cisplatin deactivation, and enhanced DNA repair/translesion synthesis) and correspondingly highlighted a few representative approaches to increase cisplatin sensitivity through improving the intracellular concentration of cisplatin and implementing combination therapy. Moreover, the requirements for future advancements in cisplatin delivery systems are rendered with emphasis on (i) understanding of nano-bio interaction and post-accumulation biological effects instead of overwhelmingly improving tumor accumulation, (ii) development of stimuli-responsive and/or actively-targeted nanomedicines, (iii) optimization of combination therapy, (iv) novel combinations targeting tumor microenvironment and immunotherapy. We postulate that cisplatin-based nanomedicines will continuously advance and potentially revolutionize oncological treatment.

Polyprodrug Nanomedicines: An Emerging Paradigm for Cancer Therapy

Nanomedicines have the potential to provide advanced therapeutic strategies in combating tumors. Polymer-prodrug-based nanomedicines are particularly attractive in cancer therapies owing to the maximum drug loading, prolonged blood circulation, and reduced premature leakage and side effects in comparison with conventional nanomaterials. However, the difficulty in precisely tuning the composition and drug loading of polymer-drug conjugates leads to batch-to-batch variations of the prodrugs, thus significantly restricting their clinical translation. Polyprodrug nanomedicines inherit the numerous intrinsic advantages of polymer-drug conjugates and exhibit well-controlled composition and drug loading via direct polymerization of therapeutic monomers, representing a promising nanomedicine for clinical tumor therapies. In this review, recent advances in the development of polyprodrug nanomedicines are summarized for tumor elimination. Various types of polyprodrug nanomedicines and the corresponding properties are first summarized. The unique advantages of polyprodrug nanomedicines and their key roles in various tumor therapies are further highlighted. Finally, current challenges and the perspectives on future research of polyprodrug nanomedicines are discussed.

Photopolymerized 3D Printing Scaffolds with Pt(IV) Prodrug Initiator for Postsurgical Tumor Treatment

Biomedical scaffolds have shown great success in postsurgical tumor treatment; their current efforts are focusing on eradicating residual tumor cells and circulating tumor cells and simultaneously repairing postoperative tissue defects. Herein, we report a novel photopolymerized 3D scaffold with Pt(IV) prodrug initiator to achieve the desired features for tumor comprehensive therapy. The Pt-GelMA scaffold was fabricated from the microfluidic 3D printing of methacrylate gelatin (GelMA) bioinks through a Pt(IV)-induced photocrosslinked process without any other additional photoinitiator and chemotherapeutic drug. Thus, the resultant scaffold displayed efficient cell killing ability against breast cancer cells in vitro and significantly inhibited the local tumor growth and distant metastases on an orthotopic postoperative breast cancer model in vivo. Besides, benefiting from their ordered porous structures and favorable biocompatibility, the scaffolds supported the cell attachment, spreading, and proliferation of normal cells in vitro; could facilitate the nutrient transportation; and induced new tissue ingrowth for repairing tissue defects caused by surgery. These properties indicate that such 3D printing scaffold is a promising candidate for efficient postoperative tumor treatment in the practical application.

Biocompatible Nanomaterials as an Emerging Technology in Reproductive Health; a Focus on the Male

A growing body of research has confirmed that nanoparticle (NP) systems can enhance delivery of therapeutic and imaging agents as well as prevent potentially damaging systemic exposure to these agents by modifying the kinetics of their release. With a wide choice of NP materials possessing different properties and surface modification options with unique targeting agents, bespoke nanosystems have been developed for applications varying from cancer therapeutics and genetic modification to cell imaging. Although there remain many challenges for the clinical application of nanoparticles, including toxicity within the reproductive system, some of these may be overcome with the recent development of biodegradable nanoparticles that offer increased biocompatibility. In recognition of this potential, this review seeks to present recent NP research with a focus on the exciting possibilities posed by the application of biocompatible nanomaterials within the fields of male reproductive medicine, health, and research.

Photoactivatable Biomedical Materials Based on Luminogens with Aggregation-Induced Emission (AIE) Characteristics

Fluorescence probes with aggregation-induced emission (AIE) property are fascinating and vital in biological fields due to their bright fluorescence in the solid state. In contrast, traditional AIE materials are obscured by the off-target effects and lack of spatial and temporal control. Photoactivatable materials with AIE characteristics, whose physicochemical behaviors can be remotely activated by light, provide great potential in biochemical information acquisition with high spatial and temporal resolution. By using AIE-featured photoactivatable fluorescence probes, accurate analysis of the targets of interest is possible. For example, where, when, and to what extent a process is started or stopped by manipulating the non-invasive light accurately. Thus, many researchers are enthusiastic about developing AIE-featured photoactivatable materials and mainly focus on developing novel molecules by rational molecular structure design, and exploring advanced applications by appropriate molecular functionalization. In this review, the recent achievements of photoactivatable materials with AIE characteristics from the aspects involving inherent mechanism of photoactivity, molecular design strategy, and the corresponding applications in biological fields, are summarized. The biological applications are highlighted and discussed, including photoactivatable bioimaging, diagnosis, and photo-controlled therapy. Finally, the challenges and prospects of the AIE-featured photoactivatable materials are also outlined and discussed.

Platinum-Induced Peripheral Neuropathy (PIPN): ROS-Related Mechanism, Therapeutic Agents, and Nanosystems

Platinum (Pt) drugs (e.g., oxaliplatin, cisplatin) are applied in the clinic worldwide for the treatment of various cancers. However, platinum-induced peripheral neuropathy (PIPN) caused by the accumulation of Pt in the peripheral nervous system limits the clinical application, whose prevention and treatment are still a huge challenge. To date, Pt-induced reactive oxygen species (ROS) generation has been studied as one of the primary mechanisms of PIPN, whose downregulation would be feasible to relieve PIPN. This review will discuss ROS-related PIPN mechanisms including Pt accumulation in the dorsal root ganglia (DRG), ROS generation, and cellular regulation. Based on them, some antioxidant therapeutic drugs will be summarized in detail to alleviate the Pt-induced ROS overproduction. More importantly, we focus on the cutting-edge nanotechnology in view of ROS-related PIPN mechanisms and will discuss the rational fabrication of tailor-made nanosystems for efficiently preventing and treating PIPN. Last, the future prospects and potential breakthroughs of these anti-ROS agents and nanosystems will be briefly discussed.

Emerging targeted drug delivery strategies toward ovarian cancer

Ovarian cancer is a high-mortality malignancy in women. The contemporary clinical chemotherapy with classic cytotoxic drugs, targeted molecular inhibitors would mostly fail when ovarian cancer cells become drug-resistant or metastasize through the body or when patients bare no more toleration because of strong adverse effects. The past decade has spotted varying targeted delivery systems including antibody-drug conjugates (ADCs), peptide/folate/aptamer-drug conjugates, polymer-drug conjugates, ligand-functionalized nanomedicines, and dual-targeted nanomedicines that upgrade ovarian cancer chemo- and molecular therapy effectively in preclinical/clinical settings via endowing therapeutic agents selectivity and bypassing drug resistance as well as lessening systemic toxicity. The targeted delivery approaches further provide means to potentiate emergent treatment modalities such as molecular therapy, gene therapy, protein therapy, photodynamic therapy, dual-targeting therapy and combination therapy for ovarian cancer. This review highlights up-to-date development of targeted drug delivery strategies toward advanced, metastatic, relapsed, and drug resistant ovarian cancers.

Dual-sensitive dual-prodrug nanoparticles with light-controlled endo/lysosomal escape for synergistic photoactivated chemotherapy

The clinical application of conventional chemotherapeutic agents, represented by cisplatin, is limited by severe side effects. So, it is essential to explore more safer and controlled drug delivery systems for synergistic chemotherapy. In this work, we designed dual-sensitive dual-prodrug nanoparticles (DDNPs) for photoactivated platinum-based synergistic chemotherapy. With photosensitivity, DDNPs could be photoactivated from inert Pt(IV) to toxic Pt(II) under safe UVA light in a spatiotemporally controlled manner. Concurrently, mild could be generated from DDNPs to assist the endo/lysosomal escape of DDNPs for better photoactivated chemotherapy (PACT). Furthermore, with acid-sensitivity, demethylcantharidin (DMC), a protein phosphatase 2A (PP2A) inhibitor, was released to block the DNA repair pathway and thereby could sensitize platinum-based chemotherapy in intracellular acidic microenvironments. Along with a precise ratio (Pt : DMC = 1 : 2), DDNPs had a powerful synergistic anti-cancer effect in vitro and in vivo. In the future, DDNPs have great potential as a safe and multifunctional drug delivery system for precise nanomedicine in clinical treatments.

Near-Infrared Light-Triggered Polyprodrug/siRNA Loaded Upconversion Nanoparticles for Multi-Modality Imaging and Synergistic Cancer Therapy

Stimuli-responsive nanosystems have been widely applied as effective modalities for drug/gene co-delivery in cancer treatment. However, precise spatiotemporal manipulations of drug/gene co-delivery, as well as multi-modality imaging-guided cancer therapy, still remain a daunting challenge. Here, multifunctional polyprodrug/siRNA loaded upconversion nanoparticles (UCNPs) are reported that combine computed tomography (CT), magnetic resonance (MR), and upconversion luminescence (UCL) tri-modality imaging and near-infrared (NIR) light-activated drug/gene on-demand delivery. The photoactivatable platinum(IV) (Pt(IV))-backbone polymers (PPt) and the siRNA targeting polo-like kinase 1 (Plk1) are loaded on the surface of polyethyleneimine (PEI)-coated UCNPs (PUCNP) to obtain the multifunctional polyprodrug/siRNA loaded UCNPs (PUCNP@Pt@siPlk1). The PUCNP@Pt@siPlk1 can be served as a "nanotransducer" to convert NIR light (980 nm) into local ultraviolet (UV) to visible light for the cleavage of photosensitive PPt, resulting in the simultaneous on-demand release of high toxic platinum(II) (Pt(II)) and siPlk1. Meanwhile, the PUCNP@Pt@siPlk1 has CT, T₁ -weighted MR, and UCL tri-modality imaging abilities. Based on these merits, PUCNP@Pt@siPlk1 displayed excellent synergistic therapeutic efficacy via image-guided and NIR light-activated platinum-based chemotherapy and RNA interfering in vitro and in vivo. Thus, this developed nanosystem with NIR light-controlled drug/gene delivery and multi-modality imaging abilities, will display great potential in combining chemotherapy and gene therapy.

Reduction-Sensitive Fluorinated-Pt(IV) Universal Transfection Nanoplatform Facilitating CT45-Targeted CRISPR/dCas9 Activation for Synergistic and Individualized Treatment of Ovarian Cancer

Compared to traditional clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9 (Cas9) system, CRISPR/dead Cas9 (dCas9) system can precisely regulate endogenous gene expression without damaging the host gene, representing a greater potential for cancer therapy. Cancer/testis antigen 45 (CT45) is proved to enhance platinum-based chemosensitivity for individualized ovarian cancer therapy. However, the development of a single nanocarrier codelivering CRISPR/dCas9 system and chemotherapeutics for synergistic cancer therapy still faces challenges. Herein, a reduction-sensitive fluorinated-Pt(IV) universal transfection nanoplatform (PtUTP-F) is developed for the CT45-targeted CRISPR/dCas9 activation to achieve synergistic and individualized treatment of ovarian cancer. Overcoming multiple physiological barriers, PtUTP-F condensed gene can efficiently transfect into different cells including 293T cells, A2780, SKOV3, A549, and A2780/cisplatin (DDP) cancer cells, which is superior to Lipofectamine 6000. With the responsive release of gene and Pt(II) in the intracellular reducing microenvironment, PtUTP-F/dCas9-CT45 can generate CRISPR/dCas9 activation of CT45 expression for protein phosphatase 4C (PP4C) activity inhibition to hinder the DNA repair pathway and thus enhances the sensitivity to Pt(II) drugs for individualized A2780 tumor therapy. The PtUTP-F not only represents a powerful nanoplatform for CRISPR/dCas9 system delivery but also initiates a novel strategy for synergistic and individualized treatment of CRISPR/dCas9-based gene therapy with chemotherapy.

Nanotechnology-Assisted RNA Delivery: From Nucleic Acid Therapeutics to COVID-19 Vaccines

In recent years, the main quest of science has been the pioneering of the groundbreaking biomedical strategies needed for achieving a personalized medicine. Ribonucleic acids (RNAs) are outstanding bioactive macromolecules identified as pivotal actors in regulating a wide range of biochemical pathways. The ability to intimately control the cell fate and tissue activities makes RNA-based drugs the most fascinating family of bioactive agents. However, achieving a widespread application of RNA therapeutics in humans is still a challenging feat, due to both the instability of naked RNA and the presence of biological barriers aimed at hindering the entrance of RNA into cells. Recently, material scientists' enormous efforts have led to the development of various classes of nanostructured carriers customized to overcome these limitations. This work systematically reviews the current advances in developing the next generation of drugs based on nanotechnology-assisted RNA delivery. The features of the most used RNA molecules are presented, together with the development strategies and properties of nanostructured vehicles. Also provided is an in-depth overview of various therapeutic applications of the presented systems, including coronavirus disease vaccines and the newest trends in the field. Lastly, emerging challenges and future perspectives for nanotechnology-mediated RNA therapies are discussed.

Nanoparticulation of Prodrug into Medicines for Cancer Therapy

This article provides a broad spectrum about the nanoprodrug fabrication advances co-driven by prodrug and nanotechnology development to potentiate cancer treatment. The nanoprodrug inherits the features of both prodrug concept and nanomedicine know-how, attempts to solve underexploited challenge in cancer treatment cooperatively. Prodrugs can release bioactive drugs on-demand at specific sites to reduce systemic toxicity, this is done by using the special properties of the tumor microenvironment, such as pH value, glutathione concentration, and specific overexpressed enzymes; or by using exogenous stimulation, such as light, heat, and ultrasound. The nanotechnology, manipulating the matter within nanoscale, has high relevance to certain biological conditions, and has been widely utilized in cancer therapy. Together, the marriage of prodrug strategy which shield the side effects of parent drug and nanotechnology with pinpoint delivery capability has conceived highly camouflaged Trojan horse to maneuver cancerous threats.

Nanotechnology lights up the antitumor potency by combining chemotherapy with siRNA

Nanotechnology-based combination anticancer therapy offers novel approaches to overcome the limitations of single-agent administration. The emerging siRNA technology combined with chemotherapy has shown considerable promise in anticancer therapy. There are three main challenges in the fabrication of siRNA/chemotherapeutic drug co-loaded nanovectors: adequate cargo protection, precise targeted delivery, and site-specific cargo release. This review presents a summary of the nanosystems that have recently been developed for co-delivering siRNA and chemotherapeutic drugs. Their combined therapeutic effects are also discussed.

Platinum(IV)-azido monocarboxylato complexes are photocytotoxic under irradiation with visible light

Complexes trans,trans,trans-[Pt(N3)2(OH)(OCOR)(py)2] where py = pyridine and where OCOR = succinate (1); 4-oxo-4-propoxybutanoate (2) and N-methylisatoate (3) have been synthesized by derivation of trans,trans,trans-[Pt(OH)2(N3)2(py)2] (4) and characterised by NMR and EPR spectroscopy, ESI-MS and X-ray crystallography. Irradiation of 1-3 with green (517 nm) light initiated photoreduction to Pt(ii) and release of the axial ligands at a 3-fold faster rate than for 4. TD-DFT calculations showed dissociative transitions at longer wavelengths for 1 compared to 4. Complexes 1 and 2 showed greater photocytotoxicity than 4 when irradiated with 420 nm light (A2780 cell line IC50 values: 2.7 and 3.7 μM) and complex 2 was particularly active towards the cisplatin-resistant cell line A2780cis (IC50 3.7 μM). Unlike 4, complexes 1-3 were phototoxic under green light irradiation (517 nm), with minimal toxicity in the dark. A pKa(H2O) of 5.13 for the free carboxylate group was determined for 1, corresponding to an overall negative charge during biological experiments, which crucially, did not appear to impede cellular accumulation and photocytotoxicity.