Multipotent Poly(Tertiary Amine-Oxide) Micelles for Efficient Cancer Drug Delivery

Enhanced Ocular Delivery of Beva via Ultra-Small Polymeric Micelles for Noninvasive Anti-VEGF Therapy

Pathological ocular neovascularization resulting from retinal ischemia constitutes a major cause of vision loss. Current anti-VEGF therapies rely on burdensome intravitreal injections of Bevacizumab (Beva). Herein ultrasmall polymeric micelles encapsulating Beva (P@Beva) are developed for noninvasive topical delivery to posterior eye tissues. Beva is efficiently loaded into 11 nm micelles fabricated via self-assembly of hyperbranched amphiphilic copolymers. The neutral, brush-like micelles demonstrate excellent drug encapsulation and colloidal stability. In vitro, P@Beva enhances intracellular delivery of Beva in ocular cells versus free drug. Ex vivo corneal and conjunctival-sclera-choroidal tissues transport after eye drops are improved 23-fold and 7.9-fold, respectively. Anti-angiogenic bioactivity is retained with P@Beva eliciting greater inhibition of endothelial tube formation and choroid sprouting over Beva alone. Remarkably, in an oxygen-induced retinopathy (OIR) model, topical P@Beva matching efficacy of intravitreal Beva injection, is the clinical standard. Comprehensive biocompatibility verifies safety. Overall, this pioneering protein delivery platform holds promise to shift paradigms from invasive intravitreal injections toward simplified, noninvasive administration of biotherapeutics targeting posterior eye diseases.

Hyaluronic acid/dextran-based polymeric micelles co-delivering ursolic acid and doxorubicin to mitochondria for potentiating chemotherapy in MDR cancer

Cancer multidrug resistance (MDR) dramatically hindered the efficiency of standard chemotherapy. Mitochondria are highly involved in the occurrence and development of MDR; thus, inducing its malfunction will be an appealing strategy to treat MDR tumors. In this paper, a natural polysaccharides-based nanoplatform (TDTD@UA/HA micelles) with cell and mitochondria dual-targeting ability was facilely fabricated to co-deliver ursolic acid (UA) and doxorubicin (DOX) for combinatorial MDR therapy. TDTD@UA/HA micelles featured a spherical morphology, narrow size distribution (∼140 nm), as well as favorable drug co-loading capacity (DOX: 8.41 %, UA: 9.06 %). After hyaluronic acid (HA)-mediated endocytosis, the lysosomal hyaluronidase promoted the degradation of HA layer and then the positive triphenylphosphine groups were exposed, which significantly enhanced the mitochondria-accumulation of nano micelles. Subsequently, DOX and UA were specifically released into mitochondria under the trigger of endogenous reactive oxygen species (ROS), followed by severe mitochondrial destruction through generating ROS, exhausting mitochondrial membrane potential, and blocking energy supply, etc.; ultimately contributing to the susceptibility restoration of MCF-7/ADR cells to chemotherapeutic agents. Importantly, TDTD@UA/HA micelles performed potent anticancer efficacy without distinct toxicity on the MDR tumor-bearing nude mice model. Overall, the versatile nanomedicine represented a new therapeutic paradigm and held great promise in overcoming MDR-related cancer.

Medicinal Chemistry of Drugs with N-Oxide Functionalities

Molecules with N-oxide functionalities are omnipresent in nature and play an important role in Medicinal Chemistry. They are synthetic or biosynthetic intermediates, prodrugs, drugs, or polymers for applications in drug development and surface engineering. Typically, the N-oxide group is critical for biomedical applications of these molecules. It may provide water solubility or decrease membrane permeability or immunogenicity. In other cases, the N-oxide has a special redox reactivity which is important for drug targeting and/or cytotoxicity. Many of the underlying mechanisms have only recently been discovered, and the number of applications of N-oxides in the healthcare field is rapidly growing. This Perspective article gives a short summary of the properties of N-oxides and their synthesis. It also provides a discussion of current applications of N-oxides in the biomedical field and explains the basic molecular mechanisms responsible for their biological activity.

Effect of biophysical properties of tumor extracellular matrix on intratumoral fate of nanoparticles: Implications on the design of nanomedicine

Nanomedicine has a profound impact on various research domains including drug delivery, diagnostics, theranostics, and regenerative medicine. Nevertheless, the clinical translation of nanomedicines for solid cancer remains limited due to the abundant physiological and pathological barriers in tumor that hinder the intratumoral penetration and distribution of these nanomedicines. In this article, we review the dynamic remodeling of tumor extracellular matrix during the tumor progression, discuss the impact of biophysical obstacles within tumors on the penetration and distribution of nanomedicines within the solid tumor and collect innovative approaches to surmount these obstacles for improving the penetration and accumulation of nanomedicines in tumor. Furthermore, we dissect the challenges and opportunities of the respective approaches, and propose potential avenues for future investigations. The purpose of this review is to provide a perspective guideline on how to effectively enhance the penetration of nanomedicines within tumors using promising methods.

Co-assembly of polymeric conjugates sensitizes neoadjuvant chemotherapy of triple-negative breast cancer with reduced systemic toxicity

Rational design of polymeric conjugates could greatly potentiate the combination therapy of solid tumors. In this study, we designed and prepared two polymeric conjugates (HT-DTX and PEG-YC-1), whereas the drugs were attached to the PEG via a linker sensitive to cathepsin B, over-expressed in TNBC. Stable nanostructures were formed by these two polymer prodrug conjugates co-assembly (PPCC). The stimuli-responsiveness of PPCC was confirmed, and the size shrinkage under tumor microenvironment would facilitate the penetration of PPCC into tumor tissue. In vitro experiments revealed the molecular mechanism for the synergistic effect of the combination of DTX and YC-1. Moreover, the systemic side effects were significantly diminished since the biodistribution of PPCC was improved after i.v. administration in vivo. In this context, the co-assembled nano-structural approach could be employed for delivering therapeutic drugs with different mechanisms of action to exert a synergistic anti-tumor effect against solid tumors, including triple-negative breast cancer. STATEMENT OF SIGNIFICANCE.

Nanoscale Covalent Organic Framework with Staggered Stacking of Phthalocyanines for Mitochondria-Targeted Photodynamic Therapy

Phthalocyanine photosensitizers (PSs) have shown promise in fluorescence imaging and photodynamic therapy (PDT) of malignant tumors, but their practical application is limited by the aggregation-induced quenching (AIQ) and inherent photobleaching of PSs. Herein, we report the synthesis of a two-dimensional nanoscale covalent organic framework (nCOF) with staggered (AB) stacking of zinc-phthalocyanines (ZnPc), ZnPc-PI, for fluorescence imaging and mitochondria-targeted PDT. ZnPc-PI isolates and confines ZnPc PSs in the rigid nCOF to reduce AIQ, improve photostability, enhance cellular uptake, and increase the level of reactive oxygen species (ROS) generation via mitochondrial targeting. ZnPc-PI shows efficient tumor accumulation, which allowed precise tumor imaging and nanoparticle tracking. With high cellular uptake and tumor accumulation, intrinsic mitochondrial targeting, and enhanced ROS generation, ZnPc-PI exhibits potent PDT efficacy with >95% tumor growth inhibition on two murine colon cancer models without causing side effects.

Nanodelivery Systems as a Novel Strategy to Overcome Treatment Failure of Cancer

Despite the tremendous progress in cancer treatment in recent decades, cancers often become resistant due to multiple mechanisms, such as intrinsic or acquired multidrug resistance, which leads to unsatisfactory treatment effects or accompanying metastasis and recurrence, ultimately to treatment failure. With a deeper understanding of the molecular mechanisms of tumors, researchers have realized that treatment designs targeting tumor resistance mechanisms would be a promising strategy to break the therapeutic deadlock. Nanodelivery systems have excellent physicochemical properties, including highly efficient tissue-specific delivery, substantial specific surface area, and controllable surface chemistry, which endow nanodelivery systems with capabilities such as precise targeting, deep penetration, responsive drug release, multidrug codelivery, and multimodal synergy, which are currently widely used in biomedical researches and bring a new dawn for overcoming cancer resistance. Based on the mechanisms of tumor therapeutic resistance, this review summarizes the research progress of nanodelivery systems for overcoming tumor resistance to improve therapeutic efficacy in recent years and offers prospects and challenges of the application of nanodelivery systems for overcoming cancer resistance.

Cancer cell membrane biomimetic nanosystem for homologous targeted dual-mode imaging and combined therapy

HYPOTHESIS

The use of tumor cell membrane-camouflaged nanoparticles, specifically the multifunctional biomimetic core-shell nanosystem MPCONPs, can enhance the targeting ability and immune escape functionality of traditional chemotherapy, leading to more precise drug delivery and improved treatment outcomes.

EXPERIMENTS

Preparation of MPCONPs: Autologous tumor cell membrane (CM) fragments are collected and used to create a shell for the nanoparticles. A trypsin-sensitive cationic polylysine framework is synthesized and embedded with oxaliplatin (l-OHP) and Ce6-AuNDs (a singlet oxygen generator). The MPCONPs are formed by assembling these components.

FINDINGS

MPCONPs, as nanoparticles camouflaged with tumor CM, have enhanced cellular uptake in cancer cells and improved the efficacy of photodynamic therapy (PDT) and chemotherapy (CT). This offers great potential for their use as individualized therapeutic agents for clinical oncology treatment.

Cell-Selective Binding Zwitterionic Polymeric Micelles Boost the Delivery Efficiency of Antibiotics

Effective accumulation and penetration of antibiotics in the biofilm are critical issues for bacterial infection treatment. Red blood cells (RBCs) have been widely utilized to hitchhike nanocarriers for drug delivery. It is vital and challenging to find a nanocarrier with an appropriate affinity toward RBCs and bacteria for selective hitchhiking and release that determines the drug delivery efficiency and specificity. Herein, we report a zwitterionic polymer poly(2-(N-oxide-N,N-diethylamino)ethyl methacrylate) (OPDEA)-based micelle, which can hitchhike on RBCs in blood and preferentially release in the infection site. We found that OPDEA could bind to the RBCs cell membrane via phospholipid-related affinity and transfer to Gram-positive bacteria due to nearly an order of magnitude stronger interaction with the bacteria cell wall. The zwitterionic surface and cell-wall affinity of OPDEA-based micelles also promote their penetration in biofilm. The clarithromycin-loaded OPDEA micelles show efficient drug delivery into the infection site, resulting in excellent therapeutic performance in both peritonitis and pneumonia models by intravenous or spray administration. This simple RBC-selective hitchhiking and releasing antibiotic delivery system provides a promising strategy for the design of antibacterial nanomedicines.

Antifouling Properties of Amine-Oxide-Containing Zwitterionic Polymers

Biofouling due to nonspecific proteins or cells on the material surfaces is a major challenge in a range of applications such as biosensors, medical devices, and implants. Even though poly(ethylene glycol) (PEG) has become the most widely used stealth material in medical and pharmaceutical products, the number of reported cases of PEG-triggered rare allergic responses continues to increase in the past decades. Herein, a new type of antifouling material poly(amine oxide) (PAO) has been evaluated as an alternative to overcome nonspecific foulant adsorption and impart comparable biocompatibility. Alkyl-substituted PAO containing diethyl, dibutyl, and dihexyl substituents are prepared, and their solution properties are studied. Photoreactive copolymers containing benzophenone as the photo-cross-linker are prepared by reversible addition-fragmentation chain-transfer polymerization and fully characterized by gel permeation chromatography and dynamic light scattering. Then, these water-soluble polymers are anchored onto a silicon wafer with the aid of UV irradiation. By evaluating the fouling resistance properties of these modified surfaces against various types of foulants, protein adsorption and bacterial attachment assays show that the cross-linked PAO-modified surface can efficiently inhibit biofouling. Furthermore, human blood cell adhesion experiments demonstrate that our PAO polymer could be used as a novel surface modifier for biomedical devices.

Biodegradable polyester-based nano drug delivery system in cancer chemotherapy: a review of recent progress (2021-2023)

Cancer presents a formidable threat to human health, with the majority of cases currently lacking a complete cure. Frequently, chemotherapy drugs are required to impede its progression. However, these drugs frequently suffer from drawbacks such as poor selectivity, limited water solubility, low bioavailability, and a propensity for causing organ toxicity. Consequently, a concerted effort has been made to seek improved drug delivery systems. Nano-drug delivery systems based on biodegradable polyesters have emerged as a subject of widespread interest in this pursuit. Extensive research has demonstrated their potential for offering high bioavailability, effective encapsulation, controlled release, and minimal toxicity. Notably, poly (ε-caprolactone) (PCL), poly (lactic-co-glycolic acid) (PLGA), and polylactic acid (PLA) have gained prominence as the most widely utilized options as carriers of the nano drug delivery system. This paper comprehensively reviews recent research on these materials as nano-carriers for delivering chemotherapeutic drugs, summarizing their latest advancements, acknowledging their limitations, and forecasting future research directions.

Single-Cell Diagnosis of Cancer Drug Resistance through the Differential Endocytosis of Nanoparticles between Drug-Resistant and Drug-Sensitive Cancer Cells

Single-cell diagnosis of cancer drug resistance is highly relevant for cancer treatment, as it can be used to identify the subpopulations of drug-resistant cancer cells, reveal the sensitivity of cancer cells to treatment, and monitor the progress of cancer drug resistance. However, simple and effective methods for cancer drug resistance detection at the single-cell level are still lacking in laboratory and clinical studies. Inspired by the fact that nanoparticles with diverse physicochemical properties would generate distinct and specific interactions with drug-resistant and drug-sensitive cancer cells, which have distinctive molecular signatures, here, we have synthesized a library of fluorescent nanoparticles with various sizes, surface charges, and compositions (SiO2 nanoparticles (SNPs), organic PS-co-PAA nanoparticles (ONPs), and ZIF-8 nanoparticles (ZNPs)), thus demonstrating that the composition has a critical influence on the interaction of nanoparticles with drug-resistant cancer cells. Furthermore, the clathrin/caveolae-independent endocytosis of ZNPs together with the P-glycoprotein-related decreased cell membrane fluidity resulted in a lower cellular accumulation of ZNPs in drug-resistant cancer cells, consequently causing the distinct cellular accumulation of ZNPs between the drug-resistant and drug-sensitive cancer cells. This difference was further quantified by detecting the fluorescence signals generated by the accumulation of nanoparticles at the single-cell level via flow cytometry. Our findings provide another insight into the nanoparticle-cell interactions and offer a promising platform for the diagnosis of cancer drug resistance of various cancer cells and clinical cancer samples at the single-cell level.

Tumor Abnormality-Oriented Nanomedicine Design

Anticancer nanomedicines have been proven effective in mitigating the side effects of chemotherapeutic drugs. However, challenges remain in augmenting their therapeutic efficacy. Nanomedicines responsive to the pathological abnormalities in the tumor microenvironment (TME) are expected to overcome the biological limitations of conventional nanomedicines, enhance the therapeutic efficacies, and further reduce the side effects. This Review aims to quantitate the various pathological abnormalities in the TME, which may serve as unique endogenous stimuli for the design of stimuli-responsive nanomedicines, and to provide a broad and objective perspective on the current understanding of stimuli-responsive nanomedicines for cancer treatment. We dissect the typical transport process and barriers of cancer drug delivery, highlight the key design principles of stimuli-responsive nanomedicines designed to tackle the series of barriers in the typical drug delivery process, and discuss the "all-into-one" and "one-for-all" strategies for integrating the needed properties for nanomedicines. Ultimately, we provide insight into the challenges and future perspectives toward the clinical translation of stimuli-responsive nanomedicines.

Tumor permeable self-delivery nanodrug targeting mitochondria for enhanced chemotherapy

Drug self-delivery systems (DSDSs) have been extensively exploited to enhance drug loading capacity and avoid excipient-related toxicity issues. However, deficient tumor targeting, inferior tumor permeability, prominent burst release, and nonspecific subcellular distribution remain major obstacles. Herein, we reported a ROS-responsive amphiphilic prodrug (CPT-S-NO) synthesized by the conjugation of zwitterionic tertiary amine-oxide (TAO) moiety and hydrophobic camptothecin (CPT) through a thioether linkage, which formed a nanoparticulate DSDS in an aqueous solution. CPT-S-NO, compared with CPT-11 and the water-soluble TAO-modified CPT prodrug (CPT-NO), exhibited prolonged blood circulation, enhanced tumor accumulation, deep tumor penetration, efficient mitochondrial targeting, and ROS-activated drug release to induce mitochondrial dysfunction, corporately conducing to the superior antitumor efficacy in vivo. This TAO decoration strategy promises potential applications in designing multipotent DSDSs for various drugs.

Physicochemical and Functional Properties and Storage Stability of Chitosan-Starch Films Containing Micellar Nano/Microstructures with Turmeric and Hibiscus Extracts

The dynamic development of the food industry and the growing interest of consumers in innovative solutions that increase the comfort and quality of life push the industry towards seeking pioneering solutions in the field of food packaging. Intelligent and active packaging, which affects the quality and durability of food products and allows one to determine their freshness, is still a modern concept. The aim of our study was to obtain two types of films based on chitosan and starch with micellar nanostructures containing extracts from turmeric rhizomes and hibiscus flowers. The presence of spherical nanostructures was confirmed using a scanning electron microscope. The structural and optical properties of the obtained composites were characterised by Fourier-transform infrared (FTIR), UltraViolet-Visible (UV-VIS), and photoluminescence (PL) spectroscopy. Scanning electron microscopy (SEM) analysis confirmed the presence of spherical micellar structures with a size of about 800 nm in the obtained biocomposites. The presence of nano-/microstructures containing extracts affected the mechanical properties of the composites: it weakened the strength of the films and improved their elongation at break (EAB). Films with nano-/microparticles were characterised by a higher water content compared to the control sample and lower solubility, and they showed stronger hydrophilic properties. Preliminary storage tests showed that the obtained biocomposites are sensitive to changes occurring during the storage of products such as cheese or fish. In addition, it was found that the film with the addition of turmeric extract inhibited the growth of microorganisms during storage. The results suggest that the obtained bionanocomposites can be used as active and/or intelligent materials.

Role of Micelle Size in Cell Transcytosis-Based Tumor Extravasation, Infiltration, and Treatment Efficacy

Transcytosis-based active transport of cancer nanomedicine has shown great promise for enhancing its tumor extravasation and infiltration and antitumor activity, but how the key nanoproperties of nanomedicine, particularly particle size, influence the transcytosis remains unknown. Herein, we used a transcytosis-inducing polymer, poly[2-(N-oxide-N,N-diethylamino)ethyl methacrylate] (OPDEA), and fabricated stable OPDEA-based micelles with different sizes (30, 70, and 140 nm in diameter) from its amphiphilic block copolymer, OPDEA-block-polystyrene (OPDEA-PS). The study of the micelle size effects on cell transcytosis, tumor extravasation, and infiltration showed that the smallest micelles (30 nm) had the fastest transcytosis and, thus, the most efficient tumor extravasation and infiltration. So, the 7-ethyl-10-hydroxyl camptothecin (SN38)-conjugated OPDEA micelles of 30 nm had much enhanced antitumor activity compared with the 140 nm micelles. These results are instructive for the design of active cancer nanomedicine.

"One-for-All" approach: a black technology for nanomedicine development?

Cancer nanomedicines require different, even opposite, properties to voyage the cascade drug delivery process involving a series of biological barriers. Currently-approved nanomedicines can only alleviate adverse effects but cannot improve patient survival because they fail to meet all the requirements. Therefore, nanocarriers with synchronized functions are highly requisite to capacitate efficient drug delivery and enhanced therapeutic efficacies. This perspective article summarizes recent advances in the two main strategies for nanomedicine design, the All-in-One approach (integration of all the functions in one system) and the One-for-All approach (one functional group with proper affinity enables all the functions), and presents our views on future nanomedicine development.

Hypoxia-Triggered Bioreduction of Poly(N-oxide)-Drug Conjugates Enhances Tumor Penetration and Antitumor Efficacy

PEGylation prolongs the blood circulation time of drugs; however, it simultaneously reduces the tumor penetration of drugs due to the nonfouling function and bulky hydrodynamic volume of PEG, leading to unsatisfactory outcomes in the treatment of solid tumors. Herein, we report the in situ growth of a bioreducible polymer of poly(N-oxide) from an important protein drug of interferon alpha (IFN) to generate site-specific IFN-poly(N-oxide) conjugates with higher bioactivity than a clinically used PEGylated IFN of PEGASYS. An IFN-poly(N-oxide) conjugate is screened out to have a circulating half-life as long as 51 h, which is similar to that of PEGASYS but 96-fold greater than that of IFN. However, the conjugate greatly outperforms PEGASYS and IFN in tumor penetration and antitumor efficacy in mice bearing melanoma. This enhanced tumor penetration is ascribed to the adsorption-mediated transcytosis of the conjugate whose poly(N-oxide) is biologically reduced into poly(tertiary amine), under hypoxia, which can be further protonated in the acidic tumor microenvironment. These novel findings demonstrate that poly(N-oxide)s are not only long-circulating but also bioreducible under hypoxia and are of great promise as next-generation carriers to deliver drugs into the interior of solid tumors to enhance their antitumor efficacy.

Determination of the critical micelle concentration of surfactants using fluorescence strategies

The increasing importance of surfactants in various fields has led to growing interest in the comprehensive characterization of surfactants. The critical micelle concentration (CMC), the most fundamental property of surfactants, is a parameter that must be measured. In particular, with the continuous expansion of the molecular structure of surfactants, numerous novel amphiphilic molecules have been developed that are capable of forming ordered aggregates in various solvent systems. Fluorescence spectroscopy, based on the differences in fluorescence intensity and wavelength of the fluorescent probe in the solvent phase and micellar phase, can sensitively detect the CMC of surfactants. This review aims to summarize the various fluorescence methods used to determine the CMC, including aggregation-induced emission (AIE), excimer formation, intramolecular charge transfer (ICT), and other miscellaneous strategies. The difficulties and limitations in the CMC determination process are also described. Further suggestions are provided to guide the existing fluorescence probes and the corresponding fluorescence methods to detect critical aggregation concentrations of amphiphilic molecules.

The tumor EPR effect for cancer drug delivery: Current status, limitations, and alternatives

Over the past three decades, the enhanced permeability and retention (EPR) effect has been considered the basis of tumor-targeted drug delivery. Various cancer nanomedicines, including macromolecular drugs, have been designed to utilize this mechanism for preferential extravasation and accumulation in solid tumors. However, such nanomedicines have not yet achieved convincing therapeutic benefits in clinics. Increasing evidence suggests that the EPR effect is over-represented in human tumors, especially in metastatic tumors. This review covers the evolution of the concept, the heterogeneity and limitation of the EPR effect in clinical realities, and prospects for alternative strategies independent of the EPR effect.

Tumor-targeted dual-starvation therapy based on redox-responsive micelle nanosystem with co-loaded LND and BPTES

The starvation therapy mediated by the lonidamine (LND) was limited by the low drug delivery efficiency, off-target effect and compensative glutamine metabolism. Herein, a hyaluronic acid (HA)-modified reduction-responsive micellar nanosystem co-loaded with glycolysis and glutamine metabolism inhibitor (LND and bis-2-(5-phenylacetmido-1,2,4-thiadiazol-2-yl)ethyl sulfide, BPTES) was constructed for tumor-targeted dual-starvation therapy. The in vitro and in vivo results collectively suggested that the fabricated nanosystem could effectively endocytosed by tumor cells via HA receptor-ligand recognition, and rapidly release starvation-inducers LND and BPTES in response to the GSH-rich intratumoral cytoplasm. Furthermore, the released LND and BPTES were capable of inducing glycolysis and glutamine metabolism suppression, and accompanied by significant mitochondrial damage, cell cycle arrest and tumor cells apoptosis, eventually devoting to the blockade of the energy and substance supply and tumor killing with high efficiency. In summary, HPPPH@L@B nanosystem significantly inhibited the compensatory glycolysis and glutamine metabolism via the dual-starvation therapy strategy, blocked the indispensable energy and substance supply of tumors, consequently leading to the desired tumor starvation and effective tumor killing with reliable biosafety.

Transcytosis-enabled active extravasation of tumor nanomedicine

Extravasation is the first step for nanomedicines in circulation to reach targeted solid tumors. Traditional nanomedicines have been designed to extravasate into tumor interstitium through the interendothelial gaps previously assumed rich in tumor blood vessels, i.e., the enhanced permeability and retention (EPR) effect. While the EPR effect has been validated in animal xenograft tumor models, accumulating evidence implies that the EPR effect is very limited and highly heterogeneous in human tumors, leading to highly unpredictable and inefficient extravasation and thus limited therapeutic efficacy of nanomedicines, including those approved in clinics. Enabling EPR-independent extravasation is the key to develop new generation of nanomedicine with enhanced efficacy. Transcytosis of tumor endothelial cells can confer nanomedicines to actively extravasate into solid tumors without relying on the EPR effect. Here, we review and prospectthe development of transcytosis-inducing nanomedicines, in hope of providing instructive insights for design of nanomedicines that can undergo selective transcellular transport across tumor endothelial cells, and thus inspiring the development of next-generation nanomedicines for clinical translation.

Fabrication, GSH-responsive drug release, and anticancer properties of thioctic acid-based intelligent hydrogels

Injectable hydrogels are potential local drug delivery systems since they contain plenty of water and soft like biological tissues. Such hydrogels could be injected directly into the tumor site where the drug is released under the tumor microenvironment. However, drug loaded hydrogels for cancer treatment based on lipoic acid (natural small molecule) have not been exploited. Here, a novel poly(lipoic acid)-poly(ethylene glycol) (PEG-PTA) hydrogels were prepared through a two-step reaction. The hydrogels contained disulfide bonds, so they could be degraded via the thiol exchange reaction with the abundant GSH in the tumor microenvironment, and subsequently release the drug. The results in vitro and at cellular level showed that the hydrogels were degraded and released the drugs only in the presence of GSH. Therefore, the injectable GSH-responsive hydrogels are promising to be served as an intelligent drug delivery system for cancer treatment.

An activatable, carrier-free, triple-combination nanomedicine for ALK/EGFR-mutant non-small cell lung cancer highly permeable targeted chemotherapy

Highly permeable targeted chemotherapy is highly desired for treating non-small cell lung cancer (NSCLC).

A dual-channel fluorescent ratio probe with hypoxia targeting and hypoxia activation capacity for tumour imaging

Efficient hypoxia diagnosis is a great challenge for nearly all solid tumours due to the operability, permeability and specificity. Although some inspiring approaches have been explored to date, it is...