Highly Augmented Drug Loading and Stability of Micellar Nanocomplexes Composed of Doxorubicin and Poly(ethylene glycol)-Green Tea Catechin Conjugate for Cancer Therapy

Carrier-free nanoparticles-new strategy of improving druggability of natural products

There are abundant natural products resources and extensive clinical use experience in China. However, the active components of natural products generally have problems such as poor water solubility and low bioavailability, which limit their druggability. Carrier-free nanoparticles, such as nanocrystals, self-assembled nanoparticles, and extracellular vesicles derived from both animal and plant sources, have great application potential in improving the safety and efficacy of drugs due to their simple and flexible preparation methods, high drug loading capacity and delivery efficiency, as well as long half-life in blood circulation. It has been widely used in biomedical fields such as anti-tumor, anti-bacterial, anti-inflammatory and anti-oxidation. Therefore, based on the natural products that have been used in clinic, this review focuses on the advantages of carrier-free nanoparticles in delivering active compounds, in order to improve the delivery process of natural products in vivo and improve their draggability.

Dietary polyphenols for tumor therapy: bioactivities, nano-therapeutic systems and delivery strategies

Various dietary polyphenols have demonstrated potent anti-tumor properties and are being evaluated as potential adjuncts in cancer treatment. Although several reviews have offered extensive insights into the anti-tumor activities of dietary polyphenols, they frequently lack a detailed discussion on the design of therapeutic protocols and targeted delivery strategies of these compounds, which impedes the translation of their biological activity into clinical practice. This article aims to deliver a comprehensive review of the anti-tumor properties of dietary polyphenols, while also examining the design and implementation of nanotherapy systems based on these compounds. Additionally, given the challenges of low water solubility and stability of dietary polyphenols, this article outlines the current methodologies for the formulation and delivery of nano-preparations to enhance tumor targeting and therapeutic efficacy. This comprehensive review aspires to deepen our understanding of the operational mechanisms of dietary polyphenols and expand their clinical applications, thereby facilitating the development of polyphenol-based dietary supplements and food additives, and promoting the progress of dietary polyphenol-related nanomedicine.

A Library of Polyphenol-Amino Acid Condensates for High-Throughput Continuous Flow Production of Nanomedicines with Ultra-High Drug Loading

Synthesizing high drug-loading nanomedicines remains a formidable challenge, and achieving universally applicable, continuous, large-scale engineered production of such nanomedicines presents even greater difficulties. This study presents a scalable library of polyphenol-amino acid condensates. By selecting amino acids, the library enables precise customization of key properties, such as carrier capacity, bioactivity, and other critical attributes, offering a versatile range of options for various application scenarios. Leveraging the properties of solvent-mediated disassembly and reassembly of condensates achieved an ultra-high drug loading of 86% for paclitaxel. For a range of poorly soluble molecules, the drug loading capacity exceeded 50%, indicating broad applicability. Furthermore, employing a continuous microfluidic device, the production rate can reach 5 mL min-1 (36 g per day), with the nanoparticle size precisely tunable and a polydispersity index (PDI) below 0.2. The polyphenol-based carrier demonstrates efficient cellular uptake and, in three distinct animal models, has been shown to enhance the therapeutic efficacy of paclitaxel without significant side effects. This study presents a streamlined, efficient, and scalable approach using microfluidics to produce nanomedicines with ultra-high drug loading, offering a promising strategy for the nanoformulation of poorly soluble drugs.

Versatile carrier-free binary nanodrug based on metformin/epigallocatechin gallate nanoparticles: exploring its properties and potential in cancer treatment

Epigallocatechin gallate (EGCG), an important active component extracted from green tea, has attracted much attention due to its multiple biological activities such as antioxidant, antibacterial, anti-inflammatory, and antitumor effects. Meanwhile, metformin (Met), a classic drug for the treatment of type 2 diabetes, exhibits additional benefits such as hypoglycemic, antioxidant, anti-inflammatory, and antitumor effects. However, metformin often causes gastrointestinal reactions when used alone, affecting patients' quality of life. In view of this, we proposed an innovative technique for the fabrication of a carrier-free, dual-loaded nanodrug, Met-EGCG nanoparticles (Met-EGCG NPs), via self-assembly. The method for preparing Met-EGCG NPs is simple, rapid and cost-effective. In addition, the carrier-free Met-EGCG NPs nanodrug inherits the strong antioxidant capacity, good biocompatibility and excellent aggregation-induced fluorescence effect of EGCG, and even offer significant advantages in enhancing drug solubility, stability, and bioavailability, while effectively reducing the occurrence of side effects. Moreover, this Met-EGCG NPs nanodrug exhibits a synergistic therapeutic effect of EGCG and metformin, thereby significantly enhancing overall therapeutic efficacy, and demonstrates excellent potential in anti-cancer applications. This study not only successfully prepared Met-EGCG NPs but also experimentally verified their superior performance, opening a new path for the application of EGCG in drug therapy. This carrier-free, dual-loaded drug delivery nanosystem based on Met-EGCG NPs offers potential for drug combination therapy, promising to play a more critical role in the biomedical field and providing new insights and guidance for the development of future multidrug delivery systems.

Tunable supramolecular self-assemblies based on cyclodextrin polymer as a loading platform for water-soluble drugs

Drug loading capacity is a crucial character of nano-scaled drug carriers to achieve high quality pharmaceutical preparations. However, efficient encapsulation of water-soluble small molecular drugs still faces large obstacles in many cases. Herein, we designed a novel supramolecular delivery system constructed by poly(β-cyclodextrin) containing benzoic acid groups (PCD-PA) and adamantyl terminated poly(ethylene glycol) (PEG-AD) to provide multiple intermolecular interactions for competent loading of water-soluble small-molecular drugs. PCD-PA had multiple host molecules, and PEG-AD could be inserted via host-guest interaction in different proportion to adjust the composition of supramolecular carrier. Meanwhile, π-π stacking and electrostatic interaction furnished by benzoic acid groups served as binding force for drug entrapment, which led to considerable loading capacity for several water-soluble drugs. Among the drugs with different chemical structures, mitoxantrone hydrochloride and doxorubicin hydrochloride bearing anthraquinone rings and several protonable amino groups acquired the highest loading content as about 14 % in PCD-PA3/PEG-AD supramolecular self-assemblies. Further computational simulations investigated the mechanism of drug loading based on the interactions between the carrier materials and the payloads. In addition, the weakly acidic environment obviously accelerated the release of certain drugs. All in all, this self-assembled supramolecular nano-system displayed great potentials as a delivery platform for diverse water-soluble drugs.

Natural epigallocatechin-3-gallocarboxylate nanoformulation loaded doxorubicin to construct a novel and low cardiotoxicity chemotherapeutic drug for high-efficiency breast cancer therapy

Anthracycline doxorubicin (DOX) remains the first-line chemotherapeutic drug for the efficient treatment of breast cancer, but its severe cardiotoxicity limits its long-term application in clinical tumor chemotherapy. Until now, the pathogenesis mechanism of DOX-induced cardiotoxicity (DIC) is still not fully understood. According to current studies, the oxidative stress caused by the imbalance of reactive oxygen species (ROS) and reactive nitrogen species (RNS) production and mitochondrial dysfunction in myocardial cells are closely related to DIC. Presently, the usual technology to solve the DIC problem is to use a multifunctional nanoplatform to load DOX and obtain a new medicinal agent, thereby enhancing the efficacy of chemotherapeutic drugs and reducing toxic side effects.Herein, the present investigation employed the Mannich condensation reaction, initiated by L-cysteine and (-)-epigallocatechin-3-gallocarboxylate (EGCG), to synthesize EGCG&Cys nanoformulation with both anti-tumor and anti-oxidant properties. The EGCG&Cys were then employed as the DOX carrier to construct a novel chemotherapeutic drug, EGCG&Cys(DOX), for high-efficiency breast cancer treatment. The tumor growth inhibition index of EGCG&Cys(DOX) in tumor-bearing mice was 12.56% superior to the DOX group with the same concentration. Meanwhile, the anti-oxidant properties of EGCG can effectively eliminate a large amount of free radicals produced by DOX and significantly alleviate DIC by improving mitochondrial functional pathways. Ultrasound echocardiography (UCG) showed that the mean LVEF and LEFS values in the 5 mg/kg DOX treatment group were significantly reduced by 54.4% and 63.4%, and the EGCG&Cys(DOX) group mice were consistent with those of the non-chemotherapy group. Moreover, electrocardiogram, serum biochemical indicators, and histopathological analysis results also demonstrate that the cardiotoxicity of EGCG&Cys(DOX) novel chemotherapy drugs is significantly reduced. Consequently, this study presents a new technology for preparing highly efficient and safe nano-chemotherapeutic drugs and an in-depth evaluation of the antitumor efficacy and safety of the synthesized novel drugs, which gave fresh life to the development of nanomedicine in the clinical treatment of breast cancer.

Self-Assembled EGCG Nanoparticles with Enhanced Intracellular ROS Scavenging for Skin Radioprotection

Purpose

Skin radiation damage is a prevalent form of tissue injury encountered during radiotherapy, radiation accidents, and occupational exposure. The only clinically approved radioprotective agent, amifostine, is associated with numerous side effects, underscoring the urgent need for the development of safe and effective radioprotective agents. Natural products with reductive properties possess high antioxidant activity and biocompatibility, but their low bioavailability limits their radioprotective efficacy and clinical application. To address this, we utilized epigallocatechin gallate (EGCG) as a model compound and employed nanotechnology to enhance cellular uptake of natural compounds, thereby improving their free radical scavenging capabilities.

Methods

EGCG nanoparticles (EGCG NPs) with robust intracellular reactive oxygen species (ROS) scavenging ability were prepared via self-assembly. The morphology, size distribution, and antioxidant capacity of EGCG NPs were characterized. Cytocompatibility, intracellular ROS levels and DNA damage, cell migration and immune response of EGCG NPs to macrophages were tested in vitro. The in vivo radiation protection and biocompatibility of EGCG NPs were assessed in murine model.

Results

The EGCG NPs was successfully prepared and compared to free EGCG, EGCG NPs demonstrated better cellular uptake, significantly enhancing their biocompatibility, intracellular ROS scavenging capacity, and ability to mitigate DNA damage. Furthermore, EGCG NPs facilitated fibroblast proliferation and migration, while inhibiting the polarization of macrophages towards the M1 phenotype in vitro. In animal levels, EGCG NPs exhibited markedly improved radioprotective efficacy over free EGCG, effectively reducing skin edema and ulceration, alleviating pathological conditions such as interstitial edema, dermal fluid accumulation, and inflammatory infiltration, decreasing the duration of skin injury, and promoting wound healing.

Conclusion

This work offers novel insights into the therapeutic application of EGCG NPs as a potential alternative for skin radioprotection and provides a powerful approach for developing radioprotective agents derived from natural products.

Active herbal ingredients and drug delivery design for tumor therapy: a review

Active herbal ingredients are gaining recognition for their potent anti-tumor efficacy, attributable to various mechanisms including tumor cell inhibition, immune system activation, and tumor angiogenesis inhibition. Recent studies have revealed that numerous anti-tumor herbal ingredients, such as ginsenosides, ursolic acid, oleanolic acid, and Angelica sinensis polysaccharides, can be utilized to develop smart drug carriers like liposomes, micelles, and nanoparticles. These carriers can deliver active herbal ingredients and co-deliver anti-tumor drugs to enhance drug accumulation at tumor sites, thereby improving anti-tumor efficacy. This study provides a comprehensive analysis of the mechanisms by which these active herbal ingredients-derived carriers enhance therapeutic outcomes. Additionally, it highlights the structural properties of these active herbal ingredients, demonstrating how their unique features can be strategically employed to design smart drug carriers with improved anti-tumor efficacy. The insights presented aim to serve as a reference and guide future innovations in the design and application of smart drug carriers for cancer therapy that leverage active herbal ingredients.

Phenolic-enabled nanotechnology: a new strategy for central nervous system disease therapy

Polyphenolic compounds have received tremendous attention in biomedicine because of their good biocompatibility and unique physicochemical properties. In recent years, phenolic-enabled nanotechnology (PEN) has become a hotspot of research in the medical field, and many promising studies have been reported, especially in the application of central nervous system (CNS) diseases. Polyphenolic compounds have superior anti-inflammatory and antioxidant properties, and can easily cross the blood‒brain barrier, as well as protect the nervous system from metabolic damage and promote learning and cognitive functions. However, although great advances have been made in this field, a comprehensive review regarding PEN-based nanomaterials for CNS therapy is lacking. A systematic summary of the basic mechanisms and synthetic strategies of PEN-based nanomaterials is beneficial for meeting the demand for the further development of novel treatments for CNS diseases. This review systematically introduces the fundamental physicochemical properties of PEN-based nanomaterials and their applications in the treatment of CNS diseases. We first describe the different ways in which polyphenols interact with other substances to form high-quality products with controlled sizes, shapes, compositions, and surface chemistry and functions. The application of PEN-based nanomaterials in the treatment of CNS diseases is then described, which provides a reference for subsequent research on the treatment of CNS diseases.

Synthesis of Mesoporous Catechin Nanoparticles as Biocompatible Drug-Free Antibacterial Mesoformulation

While polyphenolic substances stand as excellent antibacterial agents, their antimicrobial properties rely on the auxiliary support of micro-/nanostructures. Despite offering a novel avenue for enhancing polymer performance, controllable fabrication of mesoporous polymeric nanomaterials encounters significant challenges due to intricate intermolecular forces. In this article, mesoporous catechin nanoparticles have been successfully fabricated using a balanced multivariate interaction approach. The harmonization of the water-ethanol ratio and ionic strength effectively balances the forces of hydrogen bonding and π-π stacking, facilitating the controlled assembly of mesostructures. The mesoporous catechin nanoparticles exhibit a uniform spherical structure (∼100 nm), open mesopores with a diameter of ∼15 nm, and a high surface area of ∼106 m2 g-1. While exhibiting a good biocompatibility and negative surface charge, the mesoporous catechins possess outstanding antibacterial ability and function as an antibiotic mesoformulation without the necessity of loading any drugs. This mesoformulation inhibits 50% in vitro Staphylococcus aureus growth with a low concentration of ∼10 μg mL-1 and achieves complete inhibition at ∼25 μg mL-1. In a mouse wound model, accelerated wound healing and complete closure within 6-8 days are achieved. Proteomics of bacteria reveals that the excellent antibacterial property is attributed to the synergetic effect of mesoformulation's mesostructure and the catechin molecule intervening in bacterial metabolism. Overall, this work may pave a novel way for the future exploration of polymer nanomaterials and antibiotic formulations.

Visible-Light-Induced Diselenide-Crosslinked Polymeric Micelles for ROS-Triggered Drug Delivery

To synthesize an effective and versatile nano-platform serving as a promising carrier for controlled drug delivery, visible-light-induced diselenide-crosslinked polyurethane micelles were designed and prepared for ROS-triggered on-demand doxorubicin (DOX) release. A rationally designed amphiphilic block copolymer, poly(ethylene glycol)-b-poly(diselenolane diol-co-isophorone diisocyanate)-b-poly(ethylene glycol) (PEG-b-PUSe-b-PEG), which incorporates dangling diselenolane groups within the hydrophobic PU segments, was initially synthesized through the polycondensation reaction. In aqueous media, this type of amphiphilic block copolymer can self-assemble into micellar aggregates and encapsulate DOX within the micellar core, forming DOX-loaded micelles that are subsequently in situ core-crosslinked by diselenides via a visible-light-triggered metathesis reaction of Se-Se bonds. Compared with the non-crosslinked micelles (NCLMs), the as-prepared diselenide-crosslinked micelles (CLMs) exhibited a smaller particle size and improved colloidal stability. In vitro release studies have demonstrated suppressed drug release behavior for CLMs in physiological conditions, as compared to the NCLMs, whereas a burst release of DOX occurred upon exposure to an oxidation environment. Moreover, MTT assay results have revealed that the crosslinked polyurethane micelles displayed no significant cytotoxicity towards HeLa cells. Cellular uptake analyses have suggested the effective internalization of DOX-loaded crosslinked micelles and DOX release within cancer cells. These findings suggest that this kind of ROS-triggered reversibly crosslinked polyurethane micelles hold significant potential as a ROS-responsive drug delivery system.

A Polyplatin with Hands-Holding Near-Infrared-II Fluorophores and Prodrugs at a Precise Ratio for Tracking Drug Fate with Realtime Readout and Treatment Feedback

The in vivo fate of chemotherapeutic drugs plays a vital role in understanding the therapeutic outcome, side effects, and the mechanism. However, the lack of imaging abilities of drugs, tedious labeling processes, and premature leakage of imaging agents result in loss of fidelity between the drugs and imaging signals. Herein, an amphiphilic polymer is created by copolymerization of a near-infrared-II (NIR-II) fluorophore tracer (T) and an anticancer Pt(IV) prodrug (D) of cisplatin in a hand-holding manner into one polymer chain for the first time. The obtained PolyplatinDT is capable of delivering the drugs and the fluorophores concomitantly at a precise D/T ratio, thereby resulting in tracking the platinum drugs and even readout of them in real-time via NIR-II imaging. PolyplatinDT can self-assemble into nanoparticles, referred to as NanoplatinDT. Furthermore, a caspase-3 cleavable peptide that serves as an apoptosis reporter is attached to NanoplatinDT, resulting in NanoplatinDTR that are capable of simultaneously tracking platinum drugs and evaluating the therapeutic efficacy. Overall, it is reported here the design of the first theranostic polymer with anticancer drugs, drug tracers, and drug efficacy reporters that can work in concert to provide insight into the drug fate and mechanism of action.

Self-assembled metal-phenolic nanocomplexes comprised of green tea catechin for tumor-specific ferroptosis

Ferroptosis, a newly discovered form of regulated cell death, has garnered significant attention in the field of tumor therapy. However, the presence of overexpressed glutathione (GSH) and insufficient levels of H2O2 in the tumor microenvironment (TME) hinders the occurrence of ferroptosis. In response to these challenges, here we have constructed the self-assembled nanocomplexes (FeE NPs) utilizing epigallocatechin-3-gallate (EGCG) from green tea polyphenols and metal ions (Fe3+) as components. After grafting PEG, the nanocomplexes (FeE@PEG NPs) exhibit good biocompatibility and synergistically enhanced tumor-inhibitory properties. FeE@PEG NPs can be disassembled by H2O2 in the TME, leading to the rapid release of Fe3+ and EGCG. The released Fe3+ produces large amounts of toxic •OH by the Fenton reactions while having minimal impact on normal cells. The generated •OH effectively induces lipid peroxidation, which leads to ferroptosis in tumor cells. Meanwhile, the released EGCG can autoxidize to produce H2O2, which further promotes the production of •OH radicals and increases lipid peroxide levels. Moreover, EGCG also depletes the high levels of intracellular GSH, leading to an intracellular redox imbalance and triggering ferroptosis. This study provides new insights into advancing anticancer ferroptosis through rational material design, offering promising avenues for future research.

Self-assembled nanodrug delivery systems for anti-cancer drugs from traditional Chinese medicine

Traditional Chinese medicine (TCM) is a combination of raw herbs and herbal extracts with a plethora of documented beneficial bioactivities, which has unique advantages in anti-tumor therapy, and many of its major bioactive molecules have been identified in recent years due to advances in chemical separation and structural analysis. However, the major chemical classes of plant-derived bioactive compounds frequently possess chemical properties, including poor water solubility, stability, and bioavailability, that limit their therapeutic application. Alternatively, natural small molecules (NSMs) containing these components possess modifiable groups, multiple action sites, hydrophobic side chains, and a rigid skeleton with self-assembly properties that can be exploited to construct self-assembled nanoparticles with therapeutic effects superior to their individual constituents. For instance, the construction of a self-assembled nanodrug delivery system can effectively overcome the strong hydrophobicity and poor in vivo stability of NSMs, thereby greatly improving their bioavailability and enhancing their anti-tumor efficacy. This review summarizes the self-assembly methods, mechanisms, and applications of a variety of NSMs, including terpenoids, flavonoids, alkaloids, polyphenols, and saponins, providing a theoretical basis for the subsequent research on NSMs and the development of SANDDS.

EGCG-based nanoparticles: synthesis, properties, and applications

(-)-Epigallocatechin-3-gallate (EGCG) is a natural phenolic substance found in foods and beverages (especially tea) that exhibits a broad spectrum of biological activities, including antioxidant, antimicrobial, anti-obesity, anti-inflammatory, and anti-cancer properties. Its potential in cardiovascular and brain health has garnered significant attention. However, its clinical application remains limited due to its poor physicochemical stability and low oral bioavailability. Nanotechnology can be used to improve the stability, efficacy, and pharmacokinetic profile of EGCG by encapsulating it within nanoparticles. This article reviews the interactions of EGCG with various compounds, the synthesis of EGCG-based nanoparticles, the functional attributes of these nanoparticles, and their prospective applications in drug delivery, diagnosis, and therapy. The potential application of nanoencapsulated EGCG in functional foods and beverages is also emphasized. Top-down and bottom-up approaches can be used to construct EGCG-based nanoparticles. EGCG-based nanoparticles exhibit enhanced stability and bioavailability compared to free EGCG, making them promising candidates for biomedical and food applications. Notably, the non-covalent and covalent interactions of EGCG with other substances significantly contribute to the improved properties of these nanoparticles. EGCG-based nanoparticles appear to have a wide range of applications in different industries, but further research is required to enhance their efficacy and ensure their safety.

Gallic acid: design of a pyrogallol-containing hydrogel and its biomedical applications

Polyphenol hydrogels have garnered widespread attention due to their excellent adhesion, antioxidant, and antibacterial properties. Gallic acid (GA) is a typical derivative of pyrogallol that is used as a hydrogel crosslinker or bioactive additive and can be used to make multifunctional hydrogels with properties superior to those of widely studied catechol hydrogels. Furthermore, compared to polymeric tannic acid, gallic acid is more suitable for chemical modification, thus broadening its range of applications. This review focuses on multifunctional hydrogels containing GA, aiming to inspire researchers in future biomaterial design. We first revealed the interaction mechanisms between GA molecules and between GA and polymers, analyzed the characteristics GA imparts to hydrogels and compared GA hydrogels with hydrogels containing catechol. Subsequently, in this paper, various methods of integrating GA into hydrogels and the applications of GA in biomedicine are discussed, finally assessing the current limitations and future development potential of GA. In summary, GA, a natural small molecule polyphenol with excellent functionality and diverse interaction modes, has great potential in the field of biomedical hydrogels.

Package delivered: folate receptor-mediated transporters in cancer therapy and diagnosis

Neoplasias pose a significant threat to aging society, underscoring the urgent need to overcome the limitations of traditional chemotherapy through pioneering strategies. Targeted drug delivery is an evolving frontier in cancer therapy, aiming to enhance treatment efficacy while mitigating undesirable side effects. One promising avenue utilizes cell membrane receptors like the folate receptor to guide drug transporters precisely to malignant cells. Based on the cellular folate receptor as a cancer cell hallmark, targeted nanocarriers and small molecule-drug conjugates have been developed that comprise different (bio) chemistries and/or mechanical properties with individual advantages and challenges. Such modern folic acid-conjugated stimuli-responsive drug transporters provide systemic drug delivery and controlled release, enabling reduced dosages, circumvention of drug resistance, and diminished adverse effects. Since the drug transporters' structure-based de novo design is increasingly relevant for precision cancer remediation and diagnosis, this review seeks to collect and debate the recent approaches to deliver therapeutics or diagnostics based on folic acid conjugated Trojan Horses and to facilitate the understanding of the relevant chemistry and biochemical pathways. Focusing exemplarily on brain and breast cancer, recent advances spanning 2017 to 2023 in conjugated nanocarriers and small molecule drug conjugates were considered, evaluating the chemical and biological aspects in order to improve accessibility to the field and to bridge chemical and biomedical points of view ultimately guiding future research in FR-targeted cancer therapy and diagnosis.

Potentiating Gilteritinib Efficacy Using Nanocomplexation with a Hyaluronic Acid-Epigallocatechin Gallate Conjugate

Acute myeloid leukemia carrying FMS-like tyrosine kinase receptor-3 (FLT3) mutations is a fatal blood cancer with a poor prognosis. Although the FLT3 inhibitor gilteritinib has recently been approved, it still suffers from limited efficacy and relatively high nonresponse rates. In this study, we report the potentiation of gilteritinib efficacy using nanocomplexation with a hyaluronic acid-epigallocatechin gallate conjugate. The self-assembly, colloidal stability, and gilteritinib loading capacity of the nanocomplex were characterized by reversed-phase high-performance liquid chromatography and dynamic light scattering technique. Flow cytometric analysis revealed that the nanocomplex efficiently internalized into FLT3-mutated leukemic cells via specific interactions between the surface-exposed hyaluronic acid and CD44 receptor overexpressed on the cells. Moreover, this nanocomplex was found to induce an eradication of the leukemic cells in a synergistic manner by elevating the levels of reactive oxygen species and caspase-3/7 activities more effectively than free gilteritinib. This study may provide a useful strategy to design nanomedicines capable of augmenting the therapeutic efficacy of FLT3 inhibitors for effective leukemia therapy.

Comprehensive NMR Investigation of Imidazolium-Based Ionic Liquids [BMIM][OSU] and [BMIM][Cl] Impact on Binding and Dynamics of the Anticancer Drug Doxorubicin Hydrochloride

For the design of an efficient drug delivery system utilizing an ionic liquid (IL) as a carrier, it is prudent to gain molecular/atomistic level insights of a drug with IL in terms of binding and dynamics. In this scenario, the influence of anionic counterpart of imidazolium-based ILs, namely, 1-butyl-3-methyl-imidazolium octyl sulfate [BMIM][OSU] and 1-butyl-3-methyl-imidazolium chloride [BMIM][Cl] in their submicellar region ([IL] = 20 mM) on the model water-soluble anticancer drug doxorubicin hydrochloride (DOX) was probed by employing an arsenal of nuclear magnetic resonance (NMR) approaches. The salient feature of the present study includes the significant interaction of DOX with [BMIM][OSU], whereas the lack of such an interaction with [BMIM][Cl] is gauged by 1H NMR translation self-diffusometry and is further corroborated by 13C chemical shift perturbation. The two-step model was utilized to estimate the bound fraction (pb) and equivalent partition coefficient (K) of DOX with [BMIM][OSU]. A combination of selective and nonselective spin-lattice relaxation rates (R1SEL and R1NS, respectively) enables to gauze the significant interaction of DOX with [BMIM][OSU] over [BMIM][Cl]. Furthermore, 1D transient and truncated driven nuclear Overhauser enhancement (NOE) data analyses in the initial rate limit permits the evaluation of the cross-relaxation efficacy of DOX with the investigated ILs. An Arrhenius-type temperature dependence of the drug's self-diffusion was observed for DOX, DOX-[BMIM][OSU], and DOX-[BMIM][Cl] aqueous mixtures and the corresponding activation energies were evaluated.

Nanoassembly of doxorubicin-conjugated polyphosphoester and siRNA simultaneously elicited macrophage- and T cell- mediated anticancer immune response for cancer therapy

Efficiently reawakening immune cells, including T cells and macrophages, to eliminate tumor cells is a promising strategy for cancer treatment, but remains a huge challenge nowadays. Herein, a nanoassembly formed by doxorubicin (DOX)-conjugated polyphosphoester (PP-(hDOX)) and CD47-targeting siRNA (siCD47) via electrostatic and π-π stacking interactions, termed as PP-(hDOX&siCD47), was developed to reawaken the T cell and macrophage-mediated anticancer activity. The PP-(hDOX&siCD47) could efficiently blockade antiphagocytic signal by downregulation of CD47 expression to reactive macrophage-mediated anticancer immunotherapy. Moreover, the conjugated DOX of PP-(hDOX&siCD47) can perform the chemotherapy towards tumor cells and also elicit the T cell-mediated anticancer immune response via immunogenic cell death (ICD) effect. Therefore, the PP-(hDOX&siCD47) treatment could significantly increase M1-like macrophages proportion and tumor infiltration of CD8+ T cells, while the proportions of regulatory T cells (Treg) and myeloid-derived suppressor cells (MDSC) were considerably reduced in tumor tissue, eventually achieving significantly tumor growth inhibition. Overall, this study provides a simple siRNA and DOX codelivery approach to simultaneously elicit the macrophage- and T cell-mediated anticancer immune response for cancer therapy.

Macrophage-Hitchhiked Orally Administered β-Glucans-Functionalized Nanoparticles as "Precision-Guided Stealth Missiles" for Targeted Pancreatic Cancer Therapy

The prognosis in cases of pancreatic ductal adenocarcinoma (PDAC) with current treatment modalities is poor owing to the highly desmoplastic tumor microenvironment (TME). Herein, a β-glucans-functionalized zinc-doxorubicin nanoparticle system (βGlus-ZnD NPs) that can be orally administered, is developed for targeted PDAC therapy. Following oral administration in PDAC-bearing mice, βGlus-ZnD NPs actively target/transpass microfold cells, overcome the intestinal epithelial barrier, and then undergo subsequent phagocytosis by endogenous macrophages (βGlus-ZnD@Mϕ). As hitchhiking cellular vehicles, βGlus-ZnD@Mϕ transits through the intestinal lymphatic system and enters systemic circulation, ultimately accumulating in the tumor tissue as a result of the tumor-homing and "stealth" properties that are conferred by endogenous Mϕ. Meanwhile, the Mϕ that hitchhikes βGlus-ZnD NPs is activated to produce matrix metalloproteinases, destroying the desmoplastic stromal barrier, and differentiates toward the M1 -like phenotype, modulating the TME and recruiting effector T cells, ultimately inducing apoptosis of the tumor cells. The combination of βGlus-ZnD@Mϕ and immune checkpoint blockade effectively inhibits the growth of the primary tumor and suppresses the development of metastasis. It thus represents an appealing approach to targeted PDAC therapy.

Construction of multi-program responsive vitamin E succinate-chitosan-histidine nanocarrier and its response strategy in tumor therapy

Multifunctional drug delivery carriers have emerged as a promising cancer drug delivery strategy. Here, we developed a vitamin E succinate-chitosan-histidine (VCH) multi-program responsive drug carrier. The structure was characterized by FT-IR and 1H NMR spectrum, and the DLS and SEM results showed typical nanostructures. The drug loading content was 21.0 % and the corresponding encapsulation efficiency was 66.6 %. The UV-vis and fluorescence spectra demonstrated the existence of the π-π stacking interaction between DOX and VCH. Drug release experiments implied good pH sensitivity and sustained-release effect. The DOX/VCH nanoparticles could be efficiently taken up by HepG2 cancer cells and the tumor inhibition rate was up to 56.27 %. The DOX/VCH reduced the tumor volume and weight efficiently with a TIR of 45.81 %. The histological analysis results showed that DOX/VCH could effectively inhibit tumor growth and proliferation, and there was no damage to normal organs. VCH nanocarriers could combine the advantages of VES, histidine and chitosan to achieve pH sensitivity and P-gp inhibition, and effectively improve the drug solubility, targeting and lysosomal escape. Through the program response of different micro-environment, the newly developed polymeric micelles could successfully be utilized as a multi-program responsive nanocarrier system for the treatment of cancers.

Pyridine-appended disulfidephospholipids enable exceptionally high drug loading and stability as a robust liposomal platform

Low drug loading and instability of liposomes are two main challenges in the clinic. Herein, a liposomal platform from alternative pyridine-appended disulfidephospholipid (Pyr-SS-PC) was developed for delivering camptothecin (CPT) with high loading and stability. These Pyr-SS-PC lipids with π-π stacking open a general gate in the delivery of aromatic ring-containing drugs.

Metal-enriched HSP90 nanoinhibitor overcomes heat resistance in hyperthermic intraperitoneal chemotherapy used for peritoneal metastases

Clinical hyperthermic intraperitoneal chemotherapy (HIPEC) is regarded as a potential treatment that can prolong survival of patients with peritoneal metastases after cytoreductive surgery. However, treated tumor cells are prone to becoming heat resistant to HIPEC therapy through high expression of heat shock proteins (HSPs). Here, a carrier-free bifunctional nanoinhibitor was developed for HIPEC therapy in the management of peritoneal metastases. Self-assembly of the nanoinhibitor was formed by mixing Mn ion and epigallocatechin gallate (EGCG) in a controllable manner. Such nanoinhibitor directly inhibited HSP90 and impaired the HSP90 chaperone cycle by reduced intracellular ATP level. Additionally, heat and Mn ion synergistically induced oxidative stress and expression of caspase 1, which activated GSDMD by proteolysis and caused pyroptosis in tumor cells, triggering immunogenic inflammatory cell death and induced maturation of dendritic cells through the release of tumor antigens. This strategy to inhibit heat resistance in HIPEC presented an unprecedented paradigm for converting "cold" tumors into "hot" ones, thus significantly eradicating disseminated tumors located deep in the abdominal cavity and stimulating immune response in peritoneal metastases of a mouse model. Collectively, the nanoinhibitor effectively induced pyroptosis of colon tumor cells under heat conditions by inhibiting heat stress resistance and increasing oxidative stress, which may provide a new strategy for treatment of colorectal peritoneal metastases.

Challenges and opportunities for improving the druggability of natural product: Why need drug delivery system?

Bioactive natural products (BNPs) are the marrow of medicinal plants, which are the secondary metabolites of organisms and have been the most famous drug discovery database. Bioactive natural products are famous for their enormous number and great safety in medical applications. However, BNPs are troubled by their poor druggability compared with synthesis drugs and are challenged as medicine (only a few BNPs are applied in clinical settings). In order to find a reasonable solution to improving the druggability of BNPs, this review summarizes their bioactive nature based on the enormous pharmacological research and tries to explain the reasons for the poor druggability of BNPs. And then focused on the boosting research on BNPs loaded drug delivery systems, this review further concludes the advantages of drug delivery systems on the druggability improvement of BNPs from the perspective of their bioactive nature, discusses why BNPs need drug delivery systems, and predicts the next direction.

Chemoimmunological Cascade Cancer Therapy Using Fluorine Assembly Nanomedicine

Classical chemotherapeutic drugs may cause immunogenic cell death (ICD), followed by activating CD8⁺ T cells to promote cell-mediated antitumor immune responses. However, CD8⁺ T cells become exhausted due to tumor antigens' continuous stimulation, creating a major obstacle to effectively suppressing tumor growth and metastasis. Here, we develop an approach of chemo-gene combinational nanomedicine to bridge and reprogram chemotherapy and immunotherapy. The dually loaded nanomedicine induces ICD in tumor cells through doxorubicin and reverses the antitumor effects of exhausted CD8⁺ T cells through the small interfering RNA. The synergistic chemo-gene and fluorine assembly nanomedicine enriched in reactive oxygen species and acid-sensitive bonds results in enhanced cancer immunotherapy to inhibit tumor growth and the lung metastasis of breast cancer in a mouse model of breast cancer and melanoma. This study provides an efficient strategy and insights into chemoimmunological cascade therapy for combating malignant metastatic tumors.

Recent Advances of Fe(III)/Fe(II)-MPNs in Biomedical Applications

Metal-phenolic networks (MPNs) are a new type of nanomaterial self-assembled by metal ions and polyphenols that have been developed rapidly in recent decades. They have been widely investigated, in the biomedical field, for their environmental friendliness, high quality, good bio-adhesiveness, and bio-compatibility, playing a crucial role in tumor treatment. As the most common subclass of the MPNs family, Fe-based MPNs are most frequently used in chemodynamic therapy (CDT) and phototherapy (PTT), where they are often used as nanocoatings to encapsulate drugs, as well as good Fenton reagents and photosensitizers to improve tumor therapeutic efficiency substantially. In this review, strategies for preparing various types of Fe-based MPNs are first summarized. We highlight the advantages of Fe-based MPNs under the different species of polyphenol ligands for their application in tumor treatments. Finally, some current problems and challenges of Fe-based MPNs, along with a future perspective on biomedical applications, are discussed.

Modular Metal-Quinone Networks with Tunable Architecture and Functionality

Nanostructured materials with tunable structures and functionality are of interest in diverse areas. Herein, metal ions are coordinated with quinones through metal-acetylacetone coordination bonds to generate a class of structurally tunable, universally adhesive, hydrophilic, and pH-degradable materials. A library of metal-quinone networks (MQNs) is produced from five model quinone ligands paired with nine metal ions, leading to the assembly of particles, tubes, capsules, and films. Importantly, MQNs show bidirectional pH-responsive disassembly in acidic and alkaline solutions, where the quinone ligands mediate the disassembly kinetics, enabling temporal and spatial control over the release of multiple components using multilayered MQNs. Leveraging this tunable release and the inherent medicinal properties of quinones, MQN prodrugs with a high drug loading (>89 wt %) are engineered using doxorubicin for anti-cancer therapy and shikonin for the inhibition of the main protease in the SARS-CoV-2 virus.

EGCG adjuvant chemotherapy: Current status and future perspectives

The resistance of cancer cells to chemotherapeutic drugs greatly reduces the therapeutic effect in cancer patients, and the toxic side effects caused by chemotherapy also seriously affect the quality of life of patients. The combination of epigallocatechin-3-gallate (EGCG), the main active ingredient in tea, with cisplatin, 5-FU, doxorubicin and paclitaxel enhances their sensitizing effect on tumors and combats the drug resistance of cancer cells. These effects seem to be mediated by a variety of mechanisms, including combating drug resistance mediated by cancer stem cells, enhancing drug sensitivity, inducing cell cycle arrest and apoptosis, and blocking angiogenesis. In addition, EGCG can suppress a series of adverse effects caused by chemotherapy, such as gastrointestinal disorders, nephrotoxicity and cardiotoxicity, through its anti-inflammatory and antioxidant effects and improve the quality of life of patients. However, the low bioavailability and off-target effects of EGCG and its reactivity with some chemotherapeutic agents limit its clinical application. The nanomodification of EGCG and chemotherapeutic drugs not only enhances the antitumor activity but also prolongs the survival time of tumor-bearing mice, and has the advantage of low toxicity. Therefore, this review aims to discuss the current status and challenges regarding the use of EGCG in combination with chemotherapy drugs in the treatment of cancer. In general, EGCG is a promising adjuvant for chemotherapy.

Rational Understanding of Loading and Release of Doxorubicin by UV-Light- and pH-Responsive Poly(NIPAM-co-SPMA) Micelle-like Aggregates

A deep understanding of the interactions between micelle-like aggregates and antineoplastic drugs is paramount to control their adequate delivery. Herein, Poly(NIPAM-co-SPMA) copolymer nanocarriers were synthesized according to our previous published methodology, and the loading and release of poorly and highly water-soluble doxorubicin forms (Dox and Dox-HCl, respectively) were evaluated upon UV light irradiation and pH-variation stimuli. Capillary electrophoresis (CE) coupled to a fluorescence detector (LIF) allowed us to specifically characterize these systems and deeply study the loading and release processes. For this purpose, varying concentrations of doxorubicin were tested, and the loading/release rates were indirectly quantified thanks to the "free" doxorubicin concentration in solution. This study highlighted that Dox loading (9.4 μg/mg) was more effective than Dox-HCl loading (5.5 μg/mg). In contrast, 68 and 74% of Dox-HCl were respectively released after 2 min upon pH variation (from 7.4 to 6.0) and combined UV + pH 6.0 stimuli, while only 27% of Dox was invariably released upon application of the same stimuli. These results are coherent with the characteristics of both DoxHCl and Dox: Electrostatic interactions between Dox-HCl and the micelle-membrane structure (NIPAM) seemed predominant, while hydrophobic interactions were expected between Dox and the SP moieties at the inner part of the micelle-like aggregate, leading to different behaviors in both loading and release of the two doxorubicin forms. For doxorubicin loading concentrations higher than 3 μM, the electrophoretic profiles presented an additional peak. Thanks to CE characterizations, this peak was attributed to the formation of a complex formed between the nonaggregated copolymer and the doxorubicin molecules. This report therefore undergoes deep characterization of the dynamic formation of different micelle/drug complexes involved in the global drug-delivery behavior and therefore contributes to the development of more effective stimuli-responsive nanocarriers.

Role of Plant-Derived Flavonoids in Cancer Treatment

Flavonoids are polyphenolic phytochemicals, which occur naturally in plants and possess both anti-oxidant and pro-oxidant properties. Flavonoids are gaining increasing popularity in the pharmaceutical industry as healthy and cost-effective compounds. Flavonoids show beneficial pharmacological activities in the treatment and prevention of various types of diseases. They are natural and less toxic agents for cancer chemotherapy and radiotherapy via regulation of multiple cell signaling pathways and pro-oxidant effects. In this review, we have summarized the mechanisms of action of selected flavonoids, and their pharmacological implications and potential therapeutic applications in cancer therapy.

Self-Assembled Daunorubicin/Epigallocatechin Gallate Nanocomplex for Synergistic Reversal of Chemoresistance in Leukemia

Chemoresistance is one of the major challenges for the treatment of acute myeloid leukemia. Epigallocatechin gallate (EGCG), a bioactive polyphenol from green tea, has attracted immense interest as a potential chemosensitizer, but its application is limited due to the need for effective formulations capable of co-delivering EGCG and anti-leukemic drugs. Herein, we describe the formation and characterization of a micellar nanocomplex self-assembled from EGCG and daunorubicin, an anthracycline drug for the first-line treatment of acute myeloid leukemia. This nanocomplex was highly stable at pH 7.4 but stimulated to release the incorporated daunorubicin at pH 5.5, mimicking an acidic endosomal environment. More importantly, the nanocomplex exhibited superior cytotoxic efficacy against multidrug-resistant human leukemia cells over free daunorubicin by achieving a strong synergism, as supported by median-effect plot analysis. The observed chemosensitizing effect was in association with enhanced nucleus accumulation of daunorubicin, elevation of intracellular reactive oxygen species and caspase-mediated apoptosis induction. Our study presents a promising strategy for circumventing chemoresistance for more effective leukemia therapy.

NMR Studies on the Interaction of Anticancer Drug Doxorubicin with Membrane Mimetic SDS

In the formulation of efficient drug delivery systems, it is essential to unravel the structural and dynamical aspects of the drug's interaction with biological membranes. This has been done for the anticancer drug-membrane system comprising doxorubicin hydrochloride (DOX), a water-soluble anticancer drug, and the micellar sodium dodecyl sulfate (SDS), the latter serving as a useful mimic for membrane proteins. Using a multimodal NMR approach involving ¹H, ²H, and ¹³C as probe nuclei and through the determination of chemical shifts, spin-relaxation, nuclear Overhauser enhancements (NOE), and translational self-diffusion (SD), the binding characteristics of the DOX with SDS have been determined. The perturbation to ¹³C chemical shifts of SDS indicate the penetration of DOX into the SDS micelle, which is further revealed by ¹H-¹H NOESY and SD measurements. ²H spin-relaxation measurements and their analysis using a two-step model show DOX induced SDS micellar volume changes, which determine the correlation times involved in the DOX-SDS mobility.

Linoleic Acid-Glucosamine Hybrid for Endogenous Iron-Activated Ferroptosis Therapy in High-Grade Serous Ovarian Cancer

As the most common subtype in ovarian malignancies, high-grade serous ovarian cancer (HGSOC) made less therapeutic progress in past decades due to the lack of effective drug-able targets. Herein, an effective linoleic acid (LA) and glucosamine (GlcN) hybrid (LA-GlcN) was synthesized for the treatment of HGSOC. The GlcN was introduced to recognize the glucose transporter 1 (GLUT 1) overexpressed in tumor cells to enhance the uptake of LA-GlcN, and the unsaturated LA was employed to trigger ferroptosis by iron-dependent lipid peroxidation. Since the iron content of HGSOC was ∼5 and 2 times, respectively, higher than that of the normal ovarian cells and low-grade serous ovarian cancer cells, these excess irons make them a good target to enhance the ferroptosis of LA-GlcN. The in vitro study demonstrated that LA-GlcN could selectively kill HGSOC cells without affecting normal cells; the in vivo study revealed that LA-GlcN at the dose of 50 mg kg^-1 achieved a comparable tumor inhibition as doxorubicin hydrochloride (4 mg kg^-1) while the overall survival of mice was extended largely due to the low toxicity, and when the dose was increased to 100 mg kg^-1, the therapeutic outcomes could be improved further. This dietary hybrid which targets the excess endogenous iron to activate ferroptosis represents a promising drug for HGSOC treatment.

Co-amorphous systems using epigallocatechin-3-gallate as a co-former: stability, in vitro dissolution, in vivo bioavailability and underlying molecular mechanisms

Co-amorphous strategy has been extensively investigated to improve the dissolution of hydrophobic drugs. Here, epigallocatechin-3-gallate (EGCG) was exploited as a co-former in co-amorphous systems based on its unique structure including phenyl rings, phenolic hydroxyl groups and the galloyl moiety. Two model BCS class II drugs, simvastatin (SIM) and nifedipine (NIF), were selected to be co-amorphized with EGCG. All drug-EGCG systems at three molar ratios became amorphous by the means of spray drying and showed high physically stable either under dry condition and 75% RH at 40 °C or under dry conditions at 25 °C. The optimal feed molar ratios of both EGCG based co-amorphous systems fabricated were determined to be three, under which the significant increases were obtained in the maximum apparent concentrations of 4.90-fold for SIM at 1 h and 106.03-fold for NIF at 0.25 h compared to crystalline drugs by non-sink dissolution studies. The underlying molecular mechanisms of two co-amorphous systems formation were involved in molecular miscibility, hydrogen bonds and π-π stacking interactions unraveled by means of DSC, FTIR and molecular dynamics simulations. More to the point, oral pharmacokinetic studies in rats demonstrated that co-amorphous SIM-EGCG and NIF-EGCG systems at 1:3 have a significant increase in C_max of 1.81- and 5.69-fold, and AUC _{0-24 h} of 1.62- and 4.57-fold compared with those of corresponding crystalline drugs, respectively. In conclusion, EGCG is proved to be a promising co-former in co-amorphous systems.

Bioinspired poly(cation-π) micelles drug delivery platform for improving chemotherapy efficacy

Cation-π interactions widely exist in biological systems and play important roles in driving the self-assembly of biological molecules, stabilizing protein structures, and mediating molecular recognitions. Herein, a novel bioinspired poly(cation-π) micelles drug delivery platform is designed and constructed, based on the block copolymers with random cationic-aromatic sequences (amphiphilic cation-π polymer). Compared to the polymeric micelles formed by conventional amphiphilic block copolymers which are commonly limited to hydrophobic drugs loading, the engineered poly(cation-π) micelles can serve as a universal nanocarrier for a wide variety of hydrophobic and hydrophilic drugs with π-structure. It is found that due to the strong cation-π interactions integrated in the core of poly(cation-π) micelles, this nanosystem performs improved structural stability and higher drug loading capability. Especially, in the oxidation-responsive poly(cation-π) micelles as proof-of-concept, the process of stimuli-induced drug release is found significantly accelerated under the biologically relevant level of H₂O₂ in tumor microenvironment. Furthermore, the mechanism of cation-π interaction enhanced H₂O₂-sensitivity of poly(cation-π) micelles is proposed, and the improving anti-tumor efficacy is demonstrated in both in vitro and in vivo models. This work broadens the construction strategy of polymeric micelles and offers a universal drug delivery platform for efficient tumor chemotherapy.

Recent Developments of Nanostructures for the Ocular Delivery of Natural Compounds

Ocular disorders comprising various diseases of the anterior and posterior segments are considered as the main reasons for blindness. Natural products have been identified as potential treatments for ocular diseases due to their anti-oxidative, antiangiogenic, and anti-inflammatory effects. Unfortunately, most of these beneficial compounds are characterised by low solubility which results in low bioavailability and rapid systemic clearance thus requiring frequent administration or requiring high doses, which hinders their therapeutic applications. Additionally, the therapeutic efficiency of ocular drug delivery as a popular route of drug administration for the treatment of ocular diseases is restricted by various anatomical and physiological barriers. Recently, nanotechnology-based strategies including polymeric nanoparticles, micelles, nanofibers, dendrimers, lipid nanoparticles, liposomes, and niosomes have emerged as promising approaches to overcome limitations and enhance ocular drug bioavailability by effective delivery to the target sites. This review provides an overview of nano-drug delivery systems of natural compounds such as thymoquinone, catechin, epigallocatechin gallate, curcumin, berberine, pilocarpine, genistein, resveratrol, quercetin, naringenin, lutein, kaempferol, baicalin, and tetrandrine for ocular applications. This approach involves increasing drug concentration in the carriers to enhance drug movement into and through the ocular barriers.

Co-delivery of photosensitizer and diclofenac through sequentially responsive bilirubin nanocarriers for combating hypoxic tumors

Considering that photodynamic therapy (PDT)-induced oxygen consumption and microvascular damage could exacerbate hypoxia to drive more glycolysis and angiogenesis, a novel approach to potentiate PDT and overcome the resistances of hypoxia is avidly needed. Herein, morpholine-modified PEGylated bilirubin was proposed to co-deliver chlorin e6, a photosensitizer, and diclofenac (Dc). In acidic milieu, the presence of morpholine could enable the nanocarriers to selectively accumulate in tumor cells, while PDT-generated reactive oxidative species (ROS) resulted in the collapse of bilirubin nanoparticles and rapid release of Dc. Combining with Dc showed a higher rate of apoptosis over PDT alone and simultaneously triggered a domino effect, including blocking the activity and expression of lactate dehydrogenase A (LDHA), interfering with lactate secretion, suppressing the activation of various angiogenic factors and thus obviating hypoxia-induced resistance-glycolysis and angiogenesis. In addition, inhibition of hypoxia-inducible factor-1α (HIF-1α) by Dc alleviated hypoxia-induced resistance. This study offered a sequentially responsive platform to achieve sufficient tumor enrichment, on-demand drug release and superior anti-tumor outcomes in vitro and in vivo.

Rationally Driven Drug Nonradiative Decay via a Label-free Polyprodrug Strategy to Renew Tumor Cascade Photothermal-Chemotherapy

Drugs are frequently used for only chemotherapy that ignores their photophysical properties that potentially endow them with other therapeutic potency. Additionally, current photothermal-chemotherapy replies on the co-delivery of drugs and photothermal agents, but their spatiotemporal delivery and precise release is unsatisfactory. Herein, we report label-free doxorubicin (DOX) polyprodrug nanoparticles (DPNs) formulated from disulfide bonds-tethered DOX polyprodrug amphiphiles (PDMA-b-PDOXM). Benefiting from boosted nonradiative decay of high-density DOX, significant fluorescence quenching and photothermal effect are observed for DPNs without common photothermal agents. Upon cellular uptake and laser irradiation, the heat can promote lysosomal escape of DPNs into reductive cytosol, whereupon free DOX is released to activate chemotherapy and fluorescence, achieving rational cascade photothermal-chemotherapy. Current label-free polyprodrug strategy can make full use of drug, it provides an alternative insight to extend the therapeutic domain of drugs. This article is protected by copyright. All rights reserved.

Novel carrier-free, charge-reversal and DNA-affinity nanodrugs for synergistic cascade cancer chemo-chemodynamic therapy

The combination of chemotherapy (CT) and chemodynamic therapy (CDT) is an emerging therapeutic strategy for tumors; however, its therapeutic efficacy is usually impaired by the shortage of high-efficiency intracellular catalysts for CDT and the poor tumor selectivity of CT. To address this concern, novel carrier-free nanodrugs (CMC-DD2) self-assembled from the natural melanin complex (CMC) with a superior CDT performance, and dehydroabietic acid hexamer (DD2) displaying a potent antitumor activity were proposed for the synergistic combination of CT and CDT. CMC-DD2 preferred to enter tumor cells and localize in the nucleus after lysosome escape due to its pH-dependent charge-reversal properties. Nanodrugs internalized by the nucleus directly bound the DNA and altered its conformation. Then, the dissociation of CMC-DD2 was efficiently triggered by intracellular hydrogen peroxide (H₂O₂) with the release of DNA damaging agents, including nitrate anions, hydroxyl radicals (●OH) and DD2. Finally, severe DNA damage induced mitochondrial apoptosis in HepG2 cells. An in vivo assessment further demonstrated the superior tumor selectivity and suppressor capacity and no/low toxicity of the nanodrugs. Overall, novel carrier-free, charge-reversal, nucleus-targeting, biodegradable, and DNA-affinity nanodrugs represent safe and effective platforms for the combination of CT and CDT.

Self-Assembled Nanosized Vehicles from Amino Acid-Based Amphiphilic Polymers with Pendent Carboxyl Groups for Efficient Drug Delivery

Developing safe and efficient delivery vehicles for chemotherapeutic drugs has been a long-standing demanding. Amino acid-based polymers are promising candidates to address this challenge due to their excellent biocompatibility and biodegradation. Herein, a series of well-defined amphiphilic block copolymers were prepared by PET-RAFT polymerization of N-acryloyl amino acid monomers. By altering monomer types and the block ratio of the copolymers, the copolymers self-assembled into nanostructures with various morphologies, including spheres, rod-like, fibers, and lamellae via hydrophobic and hydrogen bonding interactions. Significantly, the nanoparticles (NPs) assembled from amphiphilic block copolymers poly(N-acryloyl-valine)-b-poly(N-acryloyl-aspartic acid) (PV-b-PD) displayed an appealing cargo loading efficiency (21.8-32.6%) for a broad range of drugs (paclitaxel, doxorubicin (DOX), cisplatin, etc.) due to strong interactions. The DOX-loaded PV-b-PD NPs exhibited rapid cellular uptake (within 1 min) and a great therapeutic performance. These drug delivery systems provide new insights for regulating the controlled morphologies and improving the efficiency of drug delivery.

Synergistic Therapy of a Naturally Inspired Glycopolymer-Based Biomimetic Nanomedicine Harnessing Tumor Genomic Instability

Inspired by natural saccharide-protein complexes, a stimuli-responsive biodegradable and branched glycopolymer-pyropheophorbide-a (Ppa) conjugate (BSP) with saccharide units for cancer therapy is constructed. A linear glycopolymeric conjugate (LSP), a branched glycopolymeric conjugate (BShP) from Ppa with long carbon chains, and a branched conjugate (BHSP) based on poly[N-(2-hydroxypropyl) methacrylamide] (polyHPMA) without saccharide units are prepared as controls. Through structure-activity relationship studies, BSP with a 3D network structure forms stable nanostructures via weak intermolecular interactions, regulating the stacking state of Ppa to improve the singlet oxygen quantum yield and the corresponding photodynamic therapy (PDT) effect. BSP shows high loading of olaparib, and are further coated with tumor cell membranes, resulting in a biomimetic nanomedicine (CM-BSPO). CM-BSPO shows highly efficient tumor targeting and cellular internalization properties. The engulfment of CM-BSPO accompanied with laser irradiation results in a prominent antitumor effect, evidenced by disruption of cell cycles in tumor cells, increased apoptosis and DNA damage, and subsequent inhibition of repair for damaged DNA. The mechanism for the synergistic effect from PDT and olaparib is unveiled at the genetic and protein level through transcriptome analysis. Overall, this biodegradable and branched glycopolymer-drug conjugate could be effectively optimized as a biomimetic nanomedicine for cancer therapy.

Constructing a passive targeting and long retention therapeutic nanoplatform based on water-soluble, non-toxic and highly-stable core-shell poly(amino acid) nanocomplexes

Drug delivery nanoplatforms have been applied in bioimaging, medical diagnosis, drug delivery and medical therapy. However, insolubility, toxicity, instability, nonspecific targeting and short retention of many hydrophobic drugs limit their extensive applications. Herein, we have constructed a passive targeting and long retention therapeutic nanoplatform of core-shell gefitinib/poly (ethylene glycol)-polytyrosine nanocomplexes (Gef-PY NCs). The Gef-PY NCs have good water-solubility, non-toxicity (correspond to 1/10 dosage of effective gefitinib (hydrochloride) (Gef·HCl) (normal drug administration and slow-release) and high stability (120 days, 80% drug retention at 4 or 25 °C). The core-shell Gef-PY NCs present unexpected kidney targeting and drug slow-release capacity (ca. 72 h). The good water-solubility, non-toxicity and high stability of Gef-PY NCs effectively solve the bottleneck question that Gef-based therapy could be used only in intraperitoneal injection due to its insolubility and severe toxicity. Such excellent properties (e.g., water-solubility, non-toxicity, high stability, kidney targeting and long retention) of Gef-PY NCs create their prominent anti-fibrosis capabilities, such as decreasing approximately 40% tubulointerstitial fibrosis area and 68% expression of collagen I within 7 days. This therapeutic efficacy is well-matched with that of 10 times the dosage of toxic Gef·HCl. It is very hopeful that Gef-PY NCs could realize clinical applications and such a strategy offers an effective route to design high-efficiency treatments for kidney- and tumor-related diseases.