Light-Activated ROS-Responsive Nanoplatform Codelivering Apatinib and Doxorubicin for Enhanced Chemo-Photodynamic Therapy of Multidrug-Resistant Tumors

Supramolecular nanotherapeutics based on cucurbiturils

Polymeric biomaterials have important applications in aiding clinical disease treatment, including drug delivery, bioimaging, and tissue engineering. Currently, conventional tumor chemotherapy faces obstacles such as poor solubility/stability, inability to target, and uncontrolled drug release in clinical trials, for which the emergence of supramolecular material therapeutics combining non-covalent interactions with conventional therapies is a very promising candidate. Due to their molecular recognition abilities with a range of biomolecules, cucurbit[n]uril (CB[n]), a type of macrocyclic receptors with robust backbones, hydrophobic cavities, and carbonyl-binding channels, have garnered a lot of attention. Therefore, this paper reviews recent advances in CB[n] material-based supramolecular therapeutics for clinical treatments, including targeted delivery applications and related imaging and sensing systems. This study also covers the distinctive benefits of CB materials for biological applications, as well as the trends and prospects of this interdisciplinary subject, based on numerous state-of-the-art research findings.

Tailor-Made Polysaccharides for Biomedical Applications

Polysaccharides (PSAs) are carbohydrate-based macromolecules widely used in the biomedical field, either in their pure form or in blends/nanocomposites with other materials. The relationship between structure, properties, and functions has inspired scientists to design multifunctional PSAs for various biomedical applications by incorporating unique molecular structures and targeted bulk properties. Multiple strategies, such as conjugation, grafting, cross-linking, and functionalization, have been explored to control their mechanical properties, electrical conductivity, hydrophilicity, degradability, rheological features, and stimuli-responsiveness. For instance, custom-made PSAs are known for their worldwide biomedical applications in tissue engineering, drug/gene delivery, and regenerative medicine. Furthermore, the remarkable advancements in supramolecular engineering and chemistry have paved the way for mission-oriented biomaterial synthesis and the fabrication of customized biomaterials. These materials can synergistically combine the benefits of biology and chemistry to tackle important biomedical questions. Herein, we categorize and summarize PSAs based on their synthesis methods, and explore the main strategies used to customize their chemical structures. We then highlight various properties of PSAs using practical examples. Lastly, we thoroughly describe the biomedical applications of tailor-made PSAs, along with their current existing challenges and potential future directions.

Development of an aptamer capable of multidrug resistance reversal for tumor combination chemotherapy

Multidrug resistance (MDR) is a major factor in the failure of many forms of tumor chemotherapy. Development of a specific ligand for MDR-reversal would enhance the intracellular accumulation of therapeutic agents and effectively improve the tumor treatments. Here, an aptamer was screened against a doxorubicin (DOX)-resistant human hepatocellular carcinoma cell line (HepG2/DOX) via cell-based systematic evolution of ligands by exponential enrichment. A 50 nt truncated sequence termed d3 was obtained with high affinity and specificity for HepG2/DOX cells. Multidrug resistance protein 1 (MDR1) is determined to be a possible recognition target of the selected aptamer. Aptamer d3 binding was revealed to block the MDR of the tumor cells and increase the accumulation of intracellular anticancer drugs, including DOX, vincristine, and paclitaxel, which led to a boost to the cell killing of the anticancer drugs and lowering their survival of the tumor cells. The aptamer d3-mediated MDR-reversal for effective chemotherapy was further verified in an in vivo animal model, and combination of aptamer d3 with DOX significantly improved the suppression of tumor growth by treating a xenograft HepG2/DOX tumor in vivo. This work demonstrates the feasibility of a therapeutic DNA aptamer as a tumor MDR-reversal agent, and combination of the selected aptamer with chemotherapeutic drugs shows great potential for liver cancer treatments.

A review of chemotherapeutic drugs-induced arrhythmia and potential intervention with traditional Chinese medicines

Significant advances in chemotherapy drugs have reduced mortality in patients with malignant tumors. However, chemotherapy-related cardiotoxicity increases the morbidity and mortality of patients, and has become the second leading cause of death after tumor recurrence, which has received more and more attention in recent years. Arrhythmia is one of the common types of chemotherapy-induced cardiotoxicity, and has become a new risk related to chemotherapy treatment, which seriously affects the therapeutic outcome in patients. Traditional Chinese medicine has experienced thousands of years of clinical practice in China, and has accumulated a wealth of medical theories and treatment formulas, which has unique advantages in the prevention and treatment of malignant diseases. Traditional Chinese medicine may reduce the arrhythmic toxicity caused by chemotherapy without affecting the anti-cancer effect. This paper mainly discussed the types and pathogenesis of secondary chemotherapeutic drug-induced arrhythmia (CDIA), and summarized the studies on Chinese medicine compounds, Chinese medicine Combination Formula and Chinese medicine injection that may be beneficial in intervention with secondary CDIA including atrial fibrillation, ventricular arrhythmia and sinus bradycardia, in order to provide reference for clinical prevention and treatment of chemotherapy-induced arrhythmias.

Multifunctional nanocomposites modulating the tumor microenvironment for enhanced cancer immunotherapy

Cancer immunotherapy has gained momentum for treating malignant tumors over the past decade. Checkpoint blockade and chimeric antigen receptor cell therapy (CAR-T) have shown considerable potency against liquid and solid cancers. However, the tumor microenvironment (TME) is highly immunosuppressive and hampers the effect of currently available cancer immunotherapies on overall treatment outcomes. Advancements in the design and engineering of nanomaterials have opened new avenues to modulate the TME. Progress in the current nanocomposite technology can overcome immunosuppression and trigger robust immunotherapeutic responses by integrating synergistic functions of different molecules. We will review recent advancements in nanomedical applications and discuss specifically designed nanocomposites modulating the TME for cancer immunotherapy. In addition, we provide information on the current landscape of clinical-stage nanocomposites for cancer immunotherapy.

Synergistic Photochemo Effects Based on Light-Activatable Dual Prodrug Nanoparticles for Effective Cancer Therapy

Ferroptosis is identified as a novel type of cell death with distinct properties involved in physical conditions and various diseases, including cancers. It is considered that ferroptosis provides a promising therapeutic strategy for optimizing oncotherapy. Although erastin is an effective ferroptosis trigger, the potential of its clinical application is largely restricted by its poor water solubility and concomitant limitations. To address this issue, an innovative nanoplatform (PE@PTGA) that integrated protoporphyrin IX (PpIX) and erastin coated with amphiphilic polymers (PTGA) to evoke ferroptosis and apoptosis is constructed and exemplified using an orthotopic hepatocellular carcinoma (HCC) xenograft mouse model as a paradigm. The self-assembled nanoparticles can enter HCC cells and release PpIX and erastin. With light stimulation, PpIX exerts hyperthermia and reactive oxygen species to inhibit the proliferation of HCC cells. Besides, the accumulated reactive oxygen species (ROS) can further promote erastin-induced ferroptosis in HCC cells. In vitro and in vivo studies reveal that PE@PTGA synergistically inhibits tumor development by stimulating both ferroptosis- and apoptosis-related pathways. Moreover, PE@PTGA has low toxicity and satisfactory biocompatibility, suggesting its promising clinical benefit in cancer treatments.

A pH-responsive polymer-coated CaO2as oxygen-generating nanoparticlein situfor enhanced chemo-photodynamic synergistic therapy against tumors

Photodynamic therapy (PDT) has emerged as an efficient strategy for tumor treatment. However, Insufficient amounts of inherent hypoxia and intrinsic hydrogen peroxide (H2O2) in the tumor microenvironment severely constrained PDT, as oxygen is the critical substrate for photosensitivity reaction. Here, a pH-responsive H2O2and O2self-supplying hybrid nanoparticle was designed. Through, the calcium peroxide (CaO2) as carriers loading a chemotherapeutic drug a photosensitizer 5,10,15,20-tetrakis(4-aminophenyl) porphyrin (TAPP) and doxorubicin (DOX), was covered with polyacrylic acid (PAA) to build up a feature material DOX-TAPP-CaO2@OA@PAA (denoted as DTCOP) through the reverse microemulsion method. In the acidic tumor microenvironment conditions exposing the water-sensitive CaO2nanocore to generate hydrogen peroxide (H2O2) and O2, the self-supplied O2alleviates hypoxia to enhance the PDT, and releasing DOX and TAPP. Synthetic characterization shows that the succeeded synthesized Nanocarriers could effectively carry DOX and TAPP to the tumor site and release O2at the low pH of TME. And the experimental results demonstrated that this interpose exogenous oxygen strategy is efficient at inhibition of tumor growth bothin vitroandin vivo. The nanocomposite exhibits excellent biocompatibility and the ability to inhibit tumor growth and has significant potential for the treatment of hypoxic tumors.

Recent advances in access to overcome cancer drug resistance by nanocarrier drug delivery system

Cancer is currently one of the most intractable diseases causing human death. Although the prognosis of tumor patients has been improved to a certain extent through various modern treatment methods, multidrug resistance (MDR) of tumor cells is still a major problem leading to clinical treatment failure. Chemotherapy resistance refers to the resistance of tumor cells and/or tissues to a drug, usually inherent or developed during treatment. Therefore, an urgent need to research the ideal drug delivery system to overcome the shortcoming of traditional chemotherapy. The rapid development of nanotechnology has brought us new enlightenments to solve this problem. The novel nanocarrier provides a considerably effective treatment to overcome the limitations of chemotherapy or other drugs resulting from systemic side effects such as resistance, high toxicity, lack of targeting, and off-target. Herein, we introduce several tumor MDR mechanisms and discuss novel nanoparticle technology applied to surmount cancer drug resistance. Nanomaterials contain liposomes, polymer conjugates, micelles, dendrimers, carbon-based, metal nanoparticles, and nucleotides which can be used to deliver chemotherapeutic drugs, photosensitizers, and small interfering RNA (siRNA). This review aims to elucidate the advantages of nanomedicine in overcoming cancer drug resistance and discuss the latest developments.

Intelligent delivery system targeting PD-1/PD-L1 pathway for cancer immunotherapy

The drugs targeting the PD-1/PD-L1 pathway have gained abundant clinical applications for cancer immunotherapy. However, only a part of patients benefit from such immunotherapy. Thus, brilliant novel tactic to increase the response rate of patients is on the agenda. Nanocarriers, particularly the rationally designed intelligent delivery systems with controllable therapeutic agent release ability and improved tumor targeting capacity, are firmly recommended. In light of this, state-of-the-art nanocarriers that are responsive to tumor-specific microenvironments (internal stimuli, including tumor acidic microenvironment, high level of GSH and ROS, specifically upregulated enzymes) or external stimuli (e.g., light, ultrasound, radiation) and release the target immunomodulators at tumor sites feature the advantages of increased anti-tumor potency but decreased off-target toxicity. Given the fantastic past achievements and the rapid developments in this field, the future is promising. In this review, intelligent delivery platforms targeting the PD-1/PD-L1 axis are attentively appraised. Specifically, mechanisms of the action of these stimuli-responsive drug release platforms are summarized to raise some guidelines for prior PD-1/PD-L1-based nanocarrier designs. Finally, the conclusion and outlook in intelligent delivery system targeting PD-1/PD-L1 pathway for cancer immunotherapy are outlined.

Polymeric Micellar Systems-A Special Emphasis on "Smart" Drug Delivery

Concurrent developments in anticancer nanotechnological treatments have been observed as the burden of cancer increases every year. The 21st century has seen a transformation in the study of medicine thanks to the advancement in the field of material science and nanomedicine. Improved drug delivery systems with proven efficacy and fewer side effects have been made possible. Nanoformulations with varied functions are being created using lipids, polymers, and inorganic and peptide-based nanomedicines. Therefore, thorough knowledge of these intelligent nanomedicines is crucial for developing very promising drug delivery systems. Polymeric micelles are often simple to make and have high solubilization characteristics; as a result, they seem to be a promising alternative to other nanosystems. Even though recent studies have provided an overview of polymeric micelles, here we included a discussion on the "intelligent" drug delivery from these systems. We also summarized the state-of-the-art and the most recent developments of polymeric micellar systems with respect to cancer treatments. Additionally, we gave significant attention to the clinical translation potential of polymeric micellar systems in the treatment of various cancers.

Nanocarriers overcoming biological barriers induced by multidrug resistance of chemotherapeutics in 2D and 3D cancer models

Multidrug resistance (MDR) is currently a big challenge in cancer therapy and limits its success in several patients. Tumors use the MDR mechanisms to colonize the host and reduce the efficacy of chemotherapeutics that are injected as single agents or combinations. MDR mechanisms are responsible for inactivation of drugs and formbiological barriers in cancer like the drug efflux pumps, aberrant extracellular matrix, hypoxic areas, altered cell death mechanisms, etc. Nanocarriers have some potential to overcome these barriers and improve the efficacy of chemotherapeutics. In fact, they are versatile and can deliver natural and synthetic biomolecules, as well as RNAi/DNAi, thus providing a controlled release of drugs and a synergistic effect in tumor tissues. Biocompatible and safe multifunctional biopolymers, with or without specific targeting molecules, modify the surface and interface properties of nanocarriers. These modifications affect the interaction of nanocarriers with cellular models as well as the selection of suitable models for in vitro experiments. MDR cancer cells, and particularly their 2D and 3D models, in combination with anatomical and physiological structures of tumor tissues, can boost the design and preparation of nanomedicines for anticancer therapy. 2D and 3D cancer cell cultures are suitable models to study the interaction, internalization, and efficacy of nanocarriers, the mechanisms of MDR in cancer cells and tissues, and they are used to tailor a personalized medicine and improve the efficacy of anticancer treatment in patients. The description of molecular mechanisms and physio-pathological pathways of these models further allow the design of nanomedicine that can efficiently overcome biological barriers involved in MDR and test the activity of nanocarriers in 2D and 3D models of MDR cancer cells.

A Combination of EGFR Inhibitors and AE-PDT Could Synergistically Suppress Breast Cancer Progression

BACKGROUND

Breast cancer is the most frequently diagnosed malignancy and the leading cause of cancerrelated deaths in women. Activation of EGFR by EC-secreted EGFR ligands promotes breast cancer progression. Current treatments provide limited benefits in triple-negative breast cancer (TNBC). Photodynamic therapy (PDT) has been proven effective for the treatment of TNBC through the EGFR pathway, but the underlying mechanism is still unclear.

PURPOSE

The purpose of this study was to determine the role of the EGFR pathway in the treatment of PDT on TNBC in a co-culture system.

METHODS

MB-231 and HUVEC were co-cultured for experiments (HU-231). Cell viability and ROS production were detected after AE-PDT, a combination of EGFR inhibitors (AEE788)with PDT to test angiogenesis, apoptosis, and pyroptosis. WB detects expression of EGFR. EGFR, P-EGFR, VEGF, caspase-1, capase-3, and GSDMD .

RESULTS

AE-PDT inhibited HU-231 cell proliferation and tumor angiogenesis, and induced cell apoptosis and pyroptosis by promoting ROS production. AEE788, an inhibitor of the EGFR, enhanced HU-231 cell killing after AE-PDT.

CONCLUSION

Our study suggested that the combination of EGFR inhibitors and AE-PDT could synergistically suppress breast cancer progression, providing a new treatment strategy.

Amphiphilic di-cationic methylene blue for improving antibacterial photodynamic efficiency through high accumulation and low aggregation on bacterial cell surfaces

The aggregation state of photosensitizers on the surface of bacterial cells is an important scientific problem for antibacterial photodynamic therapy (APDT). High accumulation and high photoactive state maintenance of photosensitizers are the prerequisite of high APDT efficiency. In this study, an amphiphilic di-cationic methylene blue photosensitizer (C12-MB) was synthesized through quaternization, and its structure, interface properties, photophysical properties and antibacterial photodynamic properties were studied. The results showed that C12-MB could reduce 4.27 log10 CFU and 4.8 log10 CFU for P. aeruginosa and S. aureus under irradiation of light at 660 nm, higher than the parent methylene blue. Through a spectroscopic study on photosensitizer adsorption over the bacterial surface, C12-MB can be accumulated with higher concentration, and the photo-active monomer content is 73% and 70% over P. aeruginosa and S. aureus, higher than those of methylene blue: 25% and 49%, respectively. The higher content of non-aggregated photo-active monomer could contribute to higher antibacterial photodynamic efficiency. For C12-MB adsorbed over bacterial surfaces, planar packing inhibition and electrostatic repulsion could contribute to lower C12-MB aggregation, which provides an useful reference for the structural design of high-efficiency photosensitizers.

Chondroitin sulfate-based composites: a tour d'horizon of their biomedical applications

Chondroitin sulfate (CS), a natural anionic mucopolysaccharide, belonging to the glycosaminoglycan family, acts as the primary element of the extracellular matrix (ECM) of diverse organisms. It comprises repeating units of disaccharides possessing β-1,3-linked N-acetyl galactosamine (GalNAc), and β-1,4-linked D-glucuronic acid (GlcA), and exhibits antitumor, anti-inflammatory, anti-coagulant, anti-oxidant, and anti-thrombogenic activities. It is a naturally acquired bio-macromolecule with beneficial properties, such as biocompatibility, biodegradability, and immensely low toxicity, making it the center of attention in developing biomaterials for various biomedical applications. The authors have discussed the structure, unique properties, and extraction source of CS in the initial section of this review. Further, the current investigations on applications of CS-based composites in various biomedical fields, focusing on delivering active pharmaceutical compounds, tissue engineering, and wound healing, are discussed critically. In addition, the manuscript throws light on preclinical and clinical studies associated with CS composites. A short section on Chondroitinase ABC has also been canvassed. Finally, this review emphasizes the current challenges and prospects of CS in various biomedical fields.

Physically stimulus-responsive nanoparticles for therapy and diagnosis

Nanoparticles offer numerous advantages in various fields of science, particularly in medicine. Over recent years, the use of nanoparticles in disease diagnosis and treatments has increased dramatically by the development of stimuli-responsive nano-systems, which can respond to internal or external stimuli. In the last 10 years, many preclinical studies were performed on physically triggered nano-systems to develop and optimize stable, precise, and selective therapeutic or diagnostic agents. In this regard, the systems must meet the requirements of efficacy, toxicity, pharmacokinetics, and safety before clinical investigation. Several undesired aspects need to be addressed to successfully translate these physical stimuli-responsive nano-systems, as biomaterials, into clinical practice. These have to be commonly taken into account when developing physically triggered systems; thus, also applicable for nano-systems based on nanomaterials. This review focuses on physically triggered nano-systems (PTNSs), with diagnostic or therapeutic and theranostic applications. Several types of physically triggered nano-systems based on polymeric micelles and hydrogels, mesoporous silica, and magnets are reviewed and discussed in various aspects.

Nanomedicines for Overcoming Cancer Drug Resistance

Clinically, cancer drug resistance to chemotherapy, targeted therapy or immunotherapy remains the main impediment towards curative cancer therapy, which leads directly to treatment failure along with extended hospital stays, increased medical costs and high mortality. Therefore, increasing attention has been paid to nanotechnology-based delivery systems for overcoming drug resistance in cancer. In this respect, novel tumor-targeting nanomedicines offer fairly effective therapeutic strategies for surmounting the various limitations of chemotherapy, targeted therapy and immunotherapy, enabling more precise cancer treatment, more convenient monitoring of treatment agents, as well as surmounting cancer drug resistance, including multidrug resistance (MDR). Nanotechnology-based delivery systems, including liposomes, polymer micelles, nanoparticles (NPs), and DNA nanostructures, enable a large number of properly designed therapeutic nanomedicines. In this paper, we review the different mechanisms of cancer drug resistance to chemotherapy, targeted therapy and immunotherapy, and discuss the latest developments in nanomedicines for overcoming cancer drug resistance.

Tumor pH-Responsive Nanocarriers With Light-Activatable Drug Release for Chemo-Photodynamic Therapy of Breast Cancer

Developing bioresponsive nanocarriers with particular tumor cell targeting and on-demand payload release has remained a great challenge for combined chemo-photodynamic therapy (chemo-PDT). In this study, an intelligent nanocarrier (^DATAT-NP_Ce6) responded to hierarchical endogenous tumor pH, and an exogenous red light was developed through a simple mixed micelle approach. The outside TAT ligand was masked to prevent an unexpected interaction in blood circulation. Following the accumulation of ^DATAT-NP_Ce6 in tumor tissues, tumor acidity at pH ∼6.5 recovered its targeting ability via triggering DA moiety degradation. Furthermore, the cascaded chemo-PDT was accomplished through light-stimulated nanocarrier disassembly and doxorubicin (DOX) release. Taking advantage of stability and controllability, this work provides a facile approach to designing bioresponsive nanocarriers and represents a proof-of-concept combinatorial chemo-PDT treatment.

Smart Polymeric Delivery System for Antitumor and Antimicrobial Photodynamic Therapy

Photodynamic therapy (PDT) has attracted tremendous attention in the antitumor and antimicrobial areas. To enhance the water solubility of photosensitizers and facilitate their accumulation in the tumor/infection site, polymeric materials are frequently explored as delivery systems, which are expected to show target and controllable activation of photosensitizers. This review introduces the smart polymeric delivery systems for the PDT of tumor and bacterial infections. In particular, strategies that are tumor/bacteria targeted or activatable by the tumor/bacteria microenvironment such as enzyme/pH/reactive oxygen species (ROS) are summarized. The similarities and differences of polymeric delivery systems in antitumor and antimicrobial PDT are compared. Finally, the potential challenges and perspectives of those polymeric delivery systems are discussed.

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

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

Advances in understanding the role of P-gp in doxorubicin resistance: Molecular pathways, therapeutic strategies, and prospects

P-glycoprotein (P-gp) is a drug efflux transporter that triggers doxorubicin (DOX) resistance. In this review, we highlight the molecular avenues regulating P-gp, such as Nrf2, HIF-1α, miRNAs, and long noncoding (lnc)RNAs, to reveal their participation in DOX resistance. These antitumor compounds and genetic tools synergistically reduce P-gp expression. Furthermore, ATP depletion impairs P-gp activity to enhance the antitumor activity of DOX. Nanoarchitectures, including liposomes, micelles, polymeric nanoparticles (NPs), and solid lipid nanocarriers, have been developed for the co-delivery of DOX with anticancer compounds and genes enhancing DOX cytotoxicity. Surface modification of nanocarriers, for instance with hyaluronic acid (HA), can promote selectivity toward cancer cells. We discuss these aspects with a focus on P-gp expression and activity.

Multiple-therapy strategies via polysaccharides-based nano-systems in fighting cancer

Polysaccharide-based biomaterials (e.g., chitosan, dextran, hyaluronic acid, chondroitin sulfate and heparin) have received great attention in healthcare, particularly in drug delivery for tumor therapy. They are naturally abundant and available, outstandingly biodegradable and biocompatible, and they generally have negligible toxicity and low immunogenicity. In addition, they are easily chemically or physically modified. Therefore, PSs-based nanoparticles (NPs) have been extensively investigated for the enhancement of tumor treatment. In this review, we introduce the synthetic pathways of amphiphilic PS derivatives, which allow the constructs to self-assemble into NPs with various structures. We especially offer an overview of the emerging applications of self-assembled PSs-based NPs in tumor chemotherapy, photothermal therapy (PTT), photodynamic therapy (PDT), gene therapy and immunotherapy. We believe that this review can provide criteria for a rational and molecular level-based design of PS-based NPs, and comprehensive insight into the potential of PS-based NPs used in multiple cancer therapies.

HOCl-Activated Aggregation of Gold Nanoparticles for Multimodality Therapy of Tumors

Tumor microenvironment-responsive nanodrugs offer promising opportunities for imaging-guided precision therapy with reduced side effects. Considering that the antitumor effect is closely related to the size of the nanodrugs, it is particularly important to develop a therapeutic system with size adjustability in the tumor microenvironment, which is still a great challenge in the field of nanotheranostics. Herein, a reactive oxygen species (ROS)-activated aggregation strategy is reported for imaging-guided precision therapy of tumors. The ROS-activated nanoplatform is constructed based on gold nanoparticles (AuNPs) coated with an HOCl probe on its surface (namely, Au-MB-PEG NPs). The Au-MB-PEG NPs show high sensitivity toward HOCl, resulting in the modulation of surface charge and rapid aggregation of AuNPs, and simultaneous release of methylene blue as a photosensitizer for photodynamic therapy (PDT). In the tumor environment, the aggregated AuNPs ensure higher tumor accumulation and retention. Furthermore, the redshift of the absorption of aggregated AuNPs leads to activated photoacoustic imaging signals and photothermal therapy (PTT) under near-infrared irradiation. Au-MB-PEG NPs thus efficiently inhibit the tumor growth through combined PTT-PDT therapy. This work contributes to the design of stimuli-induced size-aggregation nanodrugs, thereby attaining advanced performance in cancer diagnosis and treatment.

Enhancing the Antitumor Effect of Doxorubicin with Photosensitive Metal-Organic Framework Nanoparticles against Breast Cancer

Breast cancer is one of the most common malignant tumors in women. The existence of multiple breast cancer subtypes often leads to chemotherapy failure or the development of drug resistance. In recent years, photodynamic therapy has been proven to enhance the sensitivity of tumors to chemotherapeutic drugs. Porphyrin-based metal-organic framework (MOF) materials could simultaneously be used as carriers for chemotherapy and photosensitizers in photodynamic therapy. In this paper, doxorubicin hydrochloride (DOX) was loaded in porphyrin MOFs, and the mechanism of the synergistic effect of the DOX carriers and photodynamic therapy on breast cancer was investigated. In vitro and in vivo experiments have shown that MOFs could prolong the residence time of DOX in tumor tissues and promote the endocytosis of DOX by tumor cells. In addition, adjuvant treatment with photodynamic therapy can promote breast cancer tumors to resensitize to DOX and synergistically enhance the chemotherapy effect of DOX. Therefore, this study can provide effective development ideas for reversing drug resistance during breast cancer chemotherapy and improving the therapeutic effect of chemotherapy on breast cancer.

A MnO2-coated multivariate porphyrinic metal-organic framework for oxygen self-sufficient chemo-photodynamic synergistic therapy

Lately, chemotherapy and photodynamic therapy (PDT) synergistic therapy has become a promising anti-cancer treatment mean. However, the hypoxia in tumor leads to huge impediments to the oxygen-dependentPDT effects. In this work, a multifunctional nanoplatform (TUDMP) based on a multivariable porphyrin-nMOFs core and a manganese dioxide (MnO₂) shell was prepared for relieving tumor hypoxia and enhancing chemo-photodynamic synergistic therapy performance. The obtained TUDMP nanoplatform could effectively catalyze the hydrolysis of hydrogen peroxide to generate oxygen and also lead to consumption of antioxidant GSH, thereby facilitating the production of cytotoxic reactive oxygen species (ROS) by photosensitizer under laser irradiation. More importantly, the decomposition of the MnO₂ shell would further promote the release of the loaded doxorubicin (DOX), and thus an efficient chemo-PDT synergistic therapy was realized. Both in vitro and in vivo experimental results demonstrated the oxygen self-sufficient multifunctional nanoplatform could exhibit significantly enhanced anticancer efficiencies compared with chemotherapy or PDT alone.

A review of stimuli-responsive polymeric micelles for tumor-targeted delivery of curcumin

Despite a potential drug with multiple pharmacological activities, curcumin has disadvantages of the poor water solubility, rapid metabolism, low bioavailability, which considerably limit its clinical application. Currently, polymeric micelles (PMs) have gained widespread concern due to their advantageous physical and chemical properties, easy preparation, and biocompatibility. They can be used to improve drug solubility, prolong blood circulation time, and allow passive targeted drug delivery to tumor through enhanced penetration and retention effect. Moreover, studies focused on tumor microenvironment offer alternatives to design stimulus-responsive smart PMs based on low pH, high levels of glutathione, altered enzyme expression, increased reactive oxygen species production, and hypoxia. There are various external stimuli, such as light, ultrasound, and temperature. These endogenous/exogenous stimuli can be used for the research of intelligent micelles. Intelligent PMs can effectively load curcumin with improved solubility, and intelligently respond to release the drug at a controlled rate at targeted sites such as tumors to avoid early release, which markedly improves the bioavailability of curcumin. The present review is aimed to discuss and summarize recent developments in research of curcumin-loaded intelligent PMs based on endogenous and exogenous stimuli, and facilitates the development of novel delivery systems for future research.

Nanoparticles as therapeutic options for treating multidrug-resistant bacteria: research progress, challenges, and prospects

Resistance to antimicrobial agents has been alarming in recent years and poses a huge public health threat globally according to the WHO. The increase in morbidity and mortality resulting from microbial infections has been attributed to the emergence of multidrug-resistant microbes. Associated with the increase in multidrug resistance is the lack of new and effective antimicrobials. This has led to global initiatives to identify novel and more effective antimicrobial agents in addition to discovering novel and effective drug delivery and targeting methods. The use of nanoparticles as novel biomaterials to fully achieve this feat is currently gaining global attention. Nanoparticles could become an indispensable viable therapeutic option for treating drug-resistant infections. Of all the nanoparticles, the metals and metal oxide nanoparticles appear to offer the most promise and have attracted tremendous interest from many researchers. Moreover, the use of nanomaterials in photothermal therapy has received considerable attention over the years. This review provides current insight on antimicrobial resistance as well as the mechanisms of nanoparticle antibacterial activity. It offers an in-depth review of all the recent findings in the use of nanomaterials as agents against multi-resistant pathogenic bacteria. Also, nanomaterials that can respond to light stimuli (photothermal therapy) to kill microbes and facilitate enhanced drug delivery and release are discussed. Moreover, the synergistic interactions of nanoparticles with antibiotics and other nanomaterials, microbial adaptation strategies to nanoparticles, current challenges, and future prospects were extensively discussed.

In Situ Imaging of Cellular Reactive Oxygen Species and Caspase-3 Activity Using a Multifunctional Theranostic Probe for Cancer Diagnosis and Therapy

In this work, a multifunctional theranostic nanoprobe (Au-Ag-HM) was skillfully designed for simultaneous imaging of intracellular reactive oxygen species (ROS) and caspase-3 activity. The Au-Ag-HM was fabricated by coloading of silver nanoparticles (AgNPs) and hematoporphyrin monomethyl ether (HMME) to Au nanoflowers (AuNFs). When Au-Ag-HM was devoured by cancer cells, HepG2 cells were used as the model, and under laser irradiation, the photogenerated intracellular ROS by the photosensitizer HMME would induce the apoptosis of cancer cells. Meanwhile, the intracellular ROS triggered the oxidative etching of AgNPs on Au-Ag-HM, which led to a tremendous localized surface plasmon resonance response and scattering color changes in Au-Ag-HM, allowing in situ dark-field imaging of the ROS level in cancer cells. On the other hand, the ROS-induced activation of cellular caspase-3, which cleaved the C-peptide-containing caspase-3-specific recognition sequence (DEVD) and allowed HMME to release from the nanoprobe, resulted in a significant fluorescence recovery related to caspase-3 activity. Both photogenerated ROS and enhanced caspase-3 activity contributed to the synergistic effect of laser-mediated chemotherapy and photodynamic therapy. Therefore, the as-prepared theranostic probe could be used for simultaneous detection of cellular ROS and caspase-3 activity, distinguishing between tumor cells and normal cells, inducing the apoptosis of cancer cells, and providing a new method for diagnosis and therapy of cancer.

A new antibacterial nano-system based on hematoporphyrin-carboxymethyl chitosan conjugate for enhanced photostability and photodynamic activity

To promote bactericidal activity, improve photostability and safety, novel antibacterial nanoparticle system based on photodynamic action (PDA) was prepared here through conjugation of photosensitizer hematoporphyrin (HP) onto carboxymethyl chitosan (CMCS) via amide linkage and followed by ultrasonic treatment. The system was stable in PBS (pH 7.4) and could effectively inhibit the photodegradation of conjugated HP because of aggregation-caused quenching effect. ROS produced by the conjugated HP under light exposure could change the structure of nanoparticles by oxidizing the CMCS skeleton and thereby significantly promote the photodynamic activity of HP and its photodynamic activity after 6 h was higher than that of HP·2HCl under the same conditions. Antibacterial experiments showed that CMCS-HP nanoparticles had excellent photodynamic antibacterial activity, and the bacterial inhibition rates after 60 min of light exposure were greater than 97%. Safety evaluation exhibited that the nanoparticles were safe to mammalian cells, showing great potential for antibacterial therapy.

Hypoxia-Mediated ROS Amplification Triggers Mitochondria-Mediated Apoptotic Cell Death via PD-L1/ROS-Responsive, Dual-Targeted, Drug-Laden Thioketal Nanoparticles

Amalgamation of the reactive oxygen species (ROS)-responsive stimulus with nanoparticles has gained considerable interest owing to their high tumor specificity. Hypoxia plays a pivotal role in the acceleration of intracellular ROS production. Herein, we report the construction of a cancer cell (PD-L1)- and ROS-responsive, dual-targeted, temozolomide (TMZ)-laden nanosystem which offers a better anticancer effect in a hypoxic tumor microenvironment. A dual-targeted system boosted permeation in the cancer cells. Hypoxic conditions elevating the high ROS level accelerated the in situ release of TMZ from anti-PD-L1-TKNPs. Hyperaccumulated ROS engendered from TMZ caused oxidative damage leading to mitochondria-mediated apoptosis. TMZ fabricated in the multifunctional nanosystem (anti-PD-L1-TMZ-TKNPs) provided excellent tumor accumulation and retarded tumor growth under in vivo conditions. The elevated apoptosis effect with the activation of an apoptotic marker, DNA double-strand breakage marker, and downregulation of the angiogenesis marker in the tumor tissue following treatment with anti-PD-L1-TMZ-TKNPs exerts robust anticancer effect. Collectively, the nanoconstruct offers deep tumor permeation and high drug release and broadens the application of the ROS-responsive nanosystem for a successful anticancer effect.

TPGS and chondroitin sulfate dual-modified lipid-albumin nanosystem for targeted delivery of chemotherapeutic agent against multidrug-resistant cancer

Multidrug resistance (MDR) remains the primary issue leading to the failure of chemotherapy. In this study, a d-α-tocopherol polyethylene 1000 glycol succinate (TPGS) and chondroitin sulfate (CS) dual-modified lipid-albumin nanosystem was constructed for targeted delivery of paclitaxel (PTX) in treating MDR cancer. The obtained nanosystem (TLA/PTX@CS) had an average size of around 176 nm and a negative zeta potential of around -18 mV. TPGS was confirmed to improve the intracellular accumulation of PTX and facilitate the mitochondrial-targeting of lipid-albumin nanosystem. Functionalized with the outer CS shell, TLA/PTX@CS entered MDR breast cancer (MCF-7/MDR) cells via CD44 receptor-mediated endocytosis. CS shell was degraded by concentrated hyaluronidase in the lysosomes, thereby releasing PTX into cytoplasm and inhibiting cell proliferation. In vivo studies revealed that TLA/PTX@CS possessed prolonged blood circulation, resulting in elevated tumor accumulation, excellent antitumor efficacy with a tumor inhibition ratio of 75.3%, and significant survival benefit in MCF-7/MDR tumor-bearing mice. Hence, this TPGS and CS dual-modified lipid-albumin nanosystem provides a promising strategy for targeted delivery of chemotherapeutic drug and reversal of MDR in cancer treatment.

Recent Advances in pH- or/and Photo-Responsive Nanovehicles

The combination of nanotechnology and chemotherapy has resulted in more effective drug design via the development of nanomaterial-based drug delivery systems (DDSs) for tumor targeting. Stimulus-responsive DDSs in response to internal or external signals can offer precisely controlled delivery of preloaded therapeutics. Among the various DDSs, the photo-triggered system improves the efficacy and safety of treatment through spatiotemporal manipulation of light. Additionally, pH-induced delivery is one of the most widely studied strategies for targeting the acidic micro-environment of solid tumors. Accordingly, in this review, we discuss representative strategies for designing DDSs using light as an exogenous signal or pH as an endogenous trigger.

The reversal of chemotherapy-induced multidrug resistance by nanomedicine for cancer therapy

Multidrug resistance (MDR) of cancer is a persistent problem in chemotherapy. Scientists have considered the overexpressed efflux transporters responsible for MDR and chemotherapy failure. MDR extremely limits the therapeutic effect of chemotherapy in cancer treatment. Many strategies have been applied to solve this problem. Multifunctional nanoparticles may be one of the most promising approaches to reverse MDR of tumor. These nanoparticles can keep stability in the blood circulation and selectively accumulated in the tumor microenvironment (TME) either by passive or active targeting. The stimuli-sensitive or organelle-targeting nanoparticles can release the drug at the targeted-site without exposure to normal tissues. In order to better understand reversal of MDR, three main strategies are concluded in this review. First strategy is the synergistic effect of chemotherapeutic drugs and ABC transporter inhibitors. Through directly inhibiting overexpressed ABC transporters, chemotherapeutic drugs can enter into resistant cells without being efflux. Second strategy is based on nanoparticles circumventing over-expressed efflux transporters and directly targeting resistance-related organelles. Third approach is the combination of multiple therapy modes overcoming cancer resistance. At last, numerous researches demonstrated cancer stem-like cells (CSCs) had a deep relation with drug resistance. Here, we discuss two different drug delivery approaches of nanomedicine based on CSC therapy.

Multi-stage responsive peptide nanosensor: Anchoring EMT and mitochondria with enhanced fluorescence and boosting tumor apoptosis

Epithelial-mesenchymal transition (EMT) is closely related to tumor metastasis and invasion. Thereinto, mesenchymal tumor mitochondria are the critical target for tumor inhibition. Therefore, real-time in vivo monitoring of EMT as well as inhibiting mesenchymal tumor mitochondria is of great diagnosis and therapy significance. Herein, we construct a multi-stage recognition and morphological transformable self-assembly-peptide nano biosensor ^NDRP which can response the EMT marker and specifically damage the mesenchymal tumor cell in vivo. This nano-molar-affinity sensor is designed and screened with sensitive peptides containing a molecular switching which could be specifically triggered by the receptor to achieve the vesicle-to-fibril transformation in living system with enhanced fluorescent signal. ^NDRP nanosensor could target the tumor lesion in circulatory system, recognize mesenchymal tumor marker DDR2 (Discoidin domain receptor 2) in cellular level and specifically achieve mitochondria in subcellular level as well as damaged mitochondria which could be applied as a in vivo theranostic platform.

Nanoparticles as Drug Delivery Systems of RNAi in Cancer Therapy

RNA interference (RNAi) can mediate gene-silencing by knocking down the expression of a target gene via cellular machinery with much higher efficiency in contrast to other antisense-based approaches which represents an emerging therapeutic strategy for combating cancer. Distinct characters of nanoparticles, such as distinctive size, are fundamental for the efficient delivery of RNAi therapeutics, allowing for higher targeting and safety. In this review, we present the mechanism of RNAi and briefly describe the hurdles and concerns of RNAi as a cancer treatment approach in systemic delivery. Furthermore, the current nanovectors for effective tumor delivery of RNAi therapeutics are classified, and the characteristics of different nanocarriers are summarized.

Multifunctional nanoplatforms co-delivering combinatorial dual-drug for eliminating cancer multidrug resistance

Clinically, the primary cause of chemotherapy failure belongs to the occurrence of cancer multidrug resistance (MDR), which directly leads to the recurrence and metastasis of cancer along with high mortality. More and more attention has been paid to multifunctional nanoplatform-based dual-therapeutic combination to eliminate resistant cancers. In addition to helping both cargoes improve hydrophobicity and pharmacokinetic properties, increase bioavailability, release on demand and enhance therapeutic efficacy with low toxic effects, these smart co-delivery nanocarriers can even overcome drug resistance. Here, this review will not only present different types of co-delivery nanocarriers, but also summarize targeted and stimuli-responsive combination nanomedicines. Furthermore, we will focus on the recent progress in the co-delivery of dual-drug using such intelligent nanocarriers for surmounting cancer MDR. Whereas it remains to be seriously considered that there are some knotty issues in the fight against MDR of cancers via using co-delivery nanoplatforms, including limited intratumoral retention, the possible changes of combinatorial ratio under complex biological environments, drug release sequence from the nanocarriers, and subsequent free-drug resistance after detachment from the nanocarriers. It is hoped that, with the advantage of continuously developing nanomaterials, two personalized therapeutic agents in combination can be better exploited to achieve the goal of cooperatively combating cancer MDR, thus advancing the time to clinical transformation.

Nanomedicines for combating multidrug resistance of cancer

Chemotherapy typically involves the use of specific chemodrugs to inhibit the proliferation of cancer cells, but the frequent emergence of a variety of multidrug-resistant cancer cells poses a tremendous threat to our combat against cancer. The fundamental causes of multidrug resistance (MDR) have been studied for decades, and can be generally classified into two types: one is associated with the activation of diverse drug efflux pumps, which are responsible for translocating intracellular drug molecules out of the cells; the other is linked with some non-efflux pump-related mechanisms, such as antiapoptotic defense, enhanced DNA repair ability, and powerful antioxidant systems. To overcome MDR, intense efforts have been made to develop synergistic therapeutic strategies by introducing MDR inhibitors or combining chemotherapy with other therapeutic modalities, such as phototherapy, gene therapy, and gas therapy, in the hope that the drug-resistant cells can be sensitized toward chemotherapeutics. In particular, nanotechnology-based drug delivery platforms have shown the potential to integrate multiple therapeutic agents into one system. In this review, the focus was on the recent development of nanostrategies aiming to enhance the efficiency of chemotherapy and overcome the MDR of cancer in a synergistic manner. Different combinatorial strategies are introduced in detail and the advantages as well as underlying mechanisms of why these strategies can counteract MDR are discussed. This review is expected to shed new light on the design of advanced nanomedicines from the angle of materials and to deepen our understanding of MDR for the development of more effective anticancer strategies. This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

NIR-Controlled Treatment of Multidrug-Resistant Tumor Cells by Mesoporous Silica Capsules Containing Gold Nanorods and Doxorubicin

Multidrug resistance (MDR) is identified as a major impediment to the efficient chemotherapy of cancer, and considerable endeavors have been devoted to reverse MDR containing structuring varieties of multifunctional nanocarriers. Here, a specially light-activated hollow mesoporous silica nanocontainer with an in situ-synthesized Au nanorod (AuNR) core and a surface-modified hairpin structure DNA gatekeeper is reported for treating MDR tumor cells. In this system, the AuNR only fills part of the space in hollow mesoporous silica due to its controllable size, and the remaining space is used to load enough DOX. By controlling the near-infrared (NIR) laser intensity and exposure duration, the configuration of hairpin-structured DNA (T_m = 51.4 °C) can change reversibly and then trigger the controllable intracellular release of DOX, leading to a significantly enhanced chemotherapeutic efficacy and adjustable photothermal treatment for multidrug-resistant cancer cells. The in vitro experiments showed that this system could effectively overcome the MDR of HepG2-adm cells (a MDR cell line of human hepatocarcinoma cells) by the increased concentration of DOX intracellularly and the photothermal conversion of AuNRs, even at a low concentration (e.g., 30 μg mL^-1). Therefore, this NIR-triggered chemo-photothermal synergistic treatment system can be used as a promising efficient strategy in reversing the multidrug resistance for cancer therapy.

An Alternating Irradiation Strategy-Driven Combination Therapy of PDT and RNAi for Highly Efficient Inhibition of Tumor Growth and Metastasis

Hypoxia and hypoxia induced overexpression of vascular endothelial growth factor (VEGF) not only seriously affects the treatment effects of photodynamic therapy (PDT) but also promotes tumor metastasis. Herein, an alternating irradiation strategy (referred to as alternate use of low/high dose of light [ALHDL] irradiation)-driven combination therapy of PDT and RNA interference (RNAi) is developed to synergistically inhibit tumor growth and metastasis. A cationic amphipathic peptide (ALS) served as a carrier in the co-delivery system of photochlor (HPPH) and siVEGF (ALSH/siVEGF). At the beginning of ALHDL-driven ALSH/siVEGF treatment, short-term LDL irradiation can facilitate the tumor penetration, cellular uptake, and endosome escape of ALSH/siVEGF. Moreover, accompanied by HDL-mediated rapid cell apoptosis and LDL-mediated efficient VEGF silencing, the joint use of PDT and RNAi achieved remarkable antitumor effects both in vitro and in vivo. Importantly, benefited from the excellent performance of ALHDL in slowing the rapid deterioration of the anoxic environment of tumors, and ALSH/siVEGF treatment-mediated highly improved VEGF silencing efficacy and inhibitory effect on angiogenesis, the liver and lung metastases of HeLa cells have been successfully suppressed. Together, this study clearly indicates that ALHDL-driven combination therapy of PDT and RNAi is a highly effective modality for inhibition of tumor growth and metastasis.

Hyaluronic acid reduction-sensitive polymeric micelles achieving co-delivery of tumor-targeting paclitaxel/apatinib effectively reverse cancer multidrug resistance

Multidrug resistance (MDR) of cancer cells is a significant challenge in chemotherapy, highlighting the urgent medical need for simple and reproducible strategies to reverse this process. Here, we report the development of an active tumor-targeting and redox-responsive nanoplatform (PA-ss-NP) using hyaluronic acid-g-cystamine dihydrochloride-poly-ε-(benzyloxycarbonyl)-L-lysine (HA-ss-PLLZ) to co-deliver paclitaxel (PTX) and apatinib (APA) for effective reversal of MDR. This smart nanoplatform specifically bound to CD44 receptors, leading to selective accumulation at the tumor site and uptake by MCF-7/ADR cells. Under high concentrations of cellular glutathione (GSH), the nanocarrier was degraded rapidly with complete release of its encapsulated drugs. Released APA effectively inhibited the function of the P-glycoprotein (P-gp) drug pump and improved the sensitivity of MDR cells to chemotherapeutic agents, leading to the recovery of PTX chemosensitivity in MDR cells. As expected, this newly developed intelligent drug delivery system could effectively control MDR, both in vitro and in vivo.

Nanotechnology assisted photo- and sonodynamic therapy for overcoming drug resistance

Drug resistance is considered the most important reason for the clinical failure of cancer chemotherapy. Circumventing drug resistance and improving the efficacy of anticancer agents remains a major challenge. Over the past several decades, photodynamic therapy (PDT) and sonodynamic therapy (SDT) have attracted substantial attention for their efficacy in cancer treatment, and have been combined with chemotherapy to overcome drug resistance. However, simultaneously delivering sensitizers and chemotherapy drugs to same tumor cell remains challenging, thus greatly limiting this combinational therapy. The rapid development of nanotechnology provides a new approach to solve this problem. Nano-based drug delivery systems can not only improve the targeted delivery of agents but also co-deliver multiple drug components in single nanoparticles to achieve optimal synergistic effects. In this review, we briefly summarize the mechanisms of drug resistance, discuss the advantages and disadvantages of PDT and SDT in reversing drug resistance, and describe state-of-the-art research using nano-mediated PDT and SDT to solve these refractory problems. This review also highlights the clinical translational potential for this combinational therapy.

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

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

ROS-Responsive and active targeted drug delivery based on conjugated polymer nanoparticles for synergistic chemo-/photodynamic therapy

Stimuli-responsive and active targeted drug release is highly significant and challenging for precise and effective cancer therapy. Herein, a reactive oxygen species (ROS)-responsive drug delivery system iRGD-BDOX@CPNs with active targeting for chemo-/photodynamic (PDT) synergistic therapy has been reported. This nanocarrier iRGD-BDOX@CPNs is constructed by the self-assembly of conjugated polymer poly(fluorene-co-vinylene) (PFV), prodrug BDOX (doxorubicin modified with a phenylboronic acid ester group) and an amphiphilic polymer (DSPE-PEG) modified with internalized RGD (DSPE-PEG-iRGD). The hydrophobic inner cores formed by PFV main chains tightly enclose BDOX. Due to PFV generating many ROS by light triggering, the BDOX prodrug can be in situ activated, resulting in the highly efficient drug release. In addition, the remarkable fluorescence recovery could be used for real-time monitoring of drug delivery and guiding antitumor therapy. Contributing to the specific recognition between iRGD and integrin αvβ3 receptors over-expressed on the surface of tumor cells, the active targeting and uptake of iRGD-BDOX@CPNs in tumor cells are greatly enhanced. The prominent anti-cancer effect of iRGD-BDOX@CPNs is realized by targeted drug delivery and synergistic therapeutic effects of PDT/chemotherapy. This study illustrates that the development of ROS-responsive and targeted drug delivery nanocarriers iRGD-BDOX@CPNs provides a new insight for controllable drug release and tumor precision therapy.

Berberine-photodynamic therapy sensitizes melanoma cells to cisplatin-induced apoptosis through ROS-mediated P38 MAPK pathways

The clinical use of cisplatin are limited due to its drug resistance. Thus, it is urgent to find effective combination therapy that sensitizes tumor cells to this drug. The combined chemo-photodynamic therapy could increase anti-tumor efficacy while also reduce the side effects of cisplatin. Berberine is an isoquinoline alkaloid, which has been reported to show high photosensitizing activity. In this study, we have examined the effect of a combination of cisplatin and berberine-PDT in cisplatin-resistant melanoma cells. The cytotoxic effects of berberine-PDT alone or in combination with cisplatin were tested by MTT assays. We then examined the subcellular localization of berberine with confocal fluorescence microscopy. The percentage of apoptotic cells, the mitochondrial membrane potential (Δψm) and reactive oxygen species (ROS) generation assessed using flow cytometry analysis. Western blotting used in this study to determine the expression levels of MAPK signaling pathways and apoptosis-related proteins. Experimental data revealed that the mode of cell death is the caspase-dependent mitochondrial apoptotic pathways. Excessive accumulation of ROS played a key role in this process, which is confirmed by alleviation of cytotoxicity upon pretreatment with NAC. Furthermore, we found that the combined treatment activated MAPK signaling pathway. The inhibition of p38 MAPK by pretreating with SB203580 block the combined treatment-induced apoptotic cell death. In conclusion, berberine-PDT could be used as a chemo-sensitizer by promoting cell death through activation of a ROS/p38/caspase cascade.

Ultrasound-enhanced fluorescence imaging and chemotherapy of multidrug-resistant tumors using multifunctional dendrimer/carbon dot nanohybrids

Development of innovative nanomedicine enabling enhanced theranostics of multidrug-resistant (MDR) tumors remains to be challenging. Herein, we report the development of a newly designed multifunctional yellow-fluorescent carbon dot (y-CD)/dendrimer nanohybrids as a platform for ultrasound (US)-enhanced fluorescence imaging and chemotherapy of MDR tumors. Generation 5 (G5) poly(amidoamine) dendrimers covalently modified with efflux inhibitor of d-α-tocopheryl polyethylene glycol 1000 succinate (G5-TPGS) were complexed with one-step hydrothermally synthesized y-CDs via electrostatic interaction. The formed G5-TPGS@y-CDs complexes were then physically loaded with anticancer drug doxorubicin (DOX) to generate (G5-TPGS@y-CDs)-DOX complexes. The developed nanohybrids display a high drug loading efficiency (40.7%), strong y-CD-induced fluorescence emission, and tumor microenvironment pH-preferred DOX release profile. Attributing to the DOX/TPGS dual drug design, the (G5-TPGS@y-CDs)-DOX complexes can overcome the multidrug resistance (MDR) of cancer cells and effectively inhibit the growth of cancer cells and tumors. Furthermore, the introduction of US-targeted microbubble destruction technology was proven to render the complexes with enhanced intracellular uptake and anticancer efficacy in vitro and improved chemotherapeutic efficacy and fluorescence imaging of tumors in vivo due to the produced sonoporation effect. The developed multifunctional dendrimer/CD nanohybrids may represent an advanced design of nanomedicine for US-enhanced theranostics of different types of MDR tumors.