Nanoplatform-based natural products co-delivery system to surmount cancer multidrug-resistant

Harnessing exosomes in theranostic applications: advancements and insights in gastrointestinal cancer research

Exosomes are small extracellular vesicles (30-150 nm) that are formed by endocytosis containing complex RNA as well as protein structures and are vital in intercellular communication and can be used in gene therapy and drug delivery. According to the cell sources of origin and the environmental conditions they are exposed to, these nanovesicles are very heterogeneous and dynamic in terms of content (cargo), size and membrane composition. Exosomes are released under physiological and pathological conditions and influence the pathogenesis of cancers through various mechanisms, including angiogenesis, metastasis, immune dysregulation, drug resistance, and tumor growth/development. Gastrointestinal cancer is one of the deadliest types of cancer in humans and can involve organs e.g., the esophagus and stomach, or others such as the liver, pancreas, small intestine, and colon. Early diagnosis is very important in this field because the overall survival of patients is low due to diagnosis in late stages and recurrence. Also, various therapeutic strategies have failed and there is an unmet need for the new therapeutic agents. Exosomes can become promising candidates in gastrointestinal cancers as biomarkers and therapeutic agents due to their lower immunity and passing the main physiological barriers. In this work, we provide a general overview of exosomes, their biogenesis and biological functions. In addition, we discuss the potential of exosomes to serve as biomarkers, agents in cancer treatment, drug delivery systems, and effective vaccines in immunotherapy, with an emphasis on gastrointestinal cancers.

Natural-product-based, carrier-free, noncovalent nanoparticles for tumor chemo-photodynamic combination therapy

Cancer, with its diversity, heterogeneity, and complexity, is a significant contributor to global morbidity, disability, and mortality, highlighting the necessity for transformative treatment approaches. Photodynamic therapy (PDT) has aroused continuous interest as a viable alternative to conventional cancer treatments that encounter drug resistance. Nanotechnology has brought new advances in medicine and has shown great potential in drug delivery and cancer treatment. For precise and efficient therapeutic utilization of such a tumor therapeutic approach with high spatiotemporal selectivity and minimal invasiveness, the carrier-free noncovalent nanoparticles (NPs) based on chemo-photodynamic combination therapy is essential. Utilizing natural products as the foundation for nanodrug development offers unparalleled advantages, including exceptional pharmacological activity, easy functionalization/modification, and well biocompatibility. The natural-product-based, carrier-free, noncovalent NPs revealed excellent synergistic anticancer activity in comparison with free photosensitizers and free bioactive natural products, representing an alternative and favorable combination therapeutic avenue to improve therapeutic efficacy. Herein, a comprehensive summary of current strategies and representative application examples of carrier-free noncovalent NPs in the past decade based on natural products (such as paclitaxel, 10-hydroxycamptothecin, doxorubicin, etoposide, combretastatin A4, epigallocatechin gallate, and curcumin) for tumor chemo-photodynamic combination therapy. We highlight the insightful design and synthesis of the smart carrier-free NPs that aim to enhance PDT efficacy. Meanwhile, we discuss the future challenges and potential opportunities associated with these NPs to provide new enlightenment, spur innovative ideas, and facilitate PDT-mediated clinical transformation.

Advancements in Stimulus-Responsive Co-Delivery Nanocarriers for Enhanced Cancer Immunotherapy

Cancer immunotherapy has emerged as a novel therapeutic approach against tumors, with immune checkpoint inhibitors (ICIs) making significant clinical practice. The traditional ICIs, PD-1 and PD-L1, augment the cytotoxic function of T cells through the inhibition of tumor immune evasion pathways, ultimately leading to the initiation of an antitumor immune response. However, the clinical implementation of ICIs encounters obstacles stemming from the existence of an immunosuppressive tumor microenvironment and inadequate infiltration of CD8+T cells. Considerable attention has been directed towards advancing immunogenic cell death (ICD) as a potential solution to counteract tumor cell infiltration and the immunosuppressive tumor microenvironment. This approach holds promise in transforming "cold" tumors into "hot" tumors that exhibit responsiveness to antitumor. By combining ICD with ICIs, a synergistic immune response against tumors can be achieved. However, the combination of ICD inducers and PD-1/PD-L1 inhibitors is hindered by issues such as poor targeting and uncontrolled drug release. An advantageous solution presented by stimulus-responsive nanocarrier is integrating the physicochemical properties of ICD inducers and PD-1/PD-L1 inhibitors, facilitating precise delivery to specific tissues for optimal combination therapy. Moreover, these nanocarriers leverage the distinct features of the tumor microenvironment to accomplish controlled drug release and regulate the kinetics of drug delivery. This article aims to investigate the advancement of stimulus-responsive co-delivery nanocarriers utilizing ICD and PD-1/PD-L1 inhibitors. Special focus is dedicated to exploring the advantages and recent advancements of this system in enabling the combination of ICIs and ICD inducers. The molecular mechanisms of ICD and ICIs are concisely summarized. In conclusion, we examine the potential research prospects and challenges that could greatly enhance immunotherapeutic approaches for cancer treatment.

GSH-activable heterotrimeric nano-prodrug for precise synergistic therapy of TNBC

Combination chemotherapy is an effective approach for triple-negative breast cancer (TNBC) therapy, especially when drugs are administered at specific optimal ratios. However, at present, strategies involving precise and controllable ratios based on effective loading and release of drugs are unavailable. Herein, we designed and synthesized a glutathione (GSH)--responsive heterotrimeric prodrug and formulated it with an amphiphilic polymer to obtain nanoparticles (DSSC2 NPs) for precise synergistic chemotherapy of TNBC. The heterotrimeric prodrug was prepared using docetaxel (DTX) and curcumin (CUR) at the optimal synergistic ratio of 1: 2. DTX and CUR were covalently conjugated by disulfide linkers. Compared with control NPs, DSSC2 NPs had quantitative/ratiometric drug loading, high drug co-loading capacity, better colloidal stability, and less premature drug leakage. After systemic administration, DSSC2 NPs selectively accumulated in tumor tissues and released the encapsulated drugs triggered by high levels of GSH in cancer cells. In vitro and in vivo experiments validated that DSSC2 NPs released DTX and CUR at the predefined ratio and had a highly synergistic therapeutic effect on tumor suppression in TNBC, which can be attributed to ratiometric drug delivery and synchronous drug activation. Altogether, the heterotrimeric prodrug delivery system developed in this study represents an effective and novel approach for combination chemotherapy.

Acetyl-11-keto-beta-boswellic acid inhibits cell proliferation and growth of oral squamous cell carcinoma via RAB7B-mediated autophagy

Natural products can overcome the limitations of conventional chemotherapy. Acetyl-11-keto-beta-boswellic acid (AKBA) as a natural product extracted from frankincense, exhibited chemotherapeutic activities in different cancers. However, whether AKBA exerts inhibiting effect of oral squamous cell carcinoma (OSCC) cells growth and the mechanism need to be explored. We attempted to investigate the therapeutic effects of AKBA against OSCC and explore the mechanism involved. Here we attempt to disclose the cell-killing effect of AKBA on OSCC cell lines and try to figure out the specifical pathway. The presence of increase autophagosome and the production of mitochondrial reactive oxygen species were confirmed after the application of AKBA on OSCC cells, and RAB7B inhibition enhanced autophagosome accumulation. Though the increase autophagosome was detected induced by AKBA, autophagic flux was inhibited as the failure fusion of autophagosome and lysosome. Cal27 xenografts were established to verify the role of anti-OSCC cells of AKBA in vivo. Based above findings, we speculate that natural product AKBA suppresses OSCC cells growth via RAB7B-mediated autophagy and may serve as a promising strategy for the therapy of OSCC.

The Potential of Mushroom Extracts to Improve Chemotherapy Efficacy in Cancer Cells: A Systematic Review

Chemoresistance is a challenge in cancer treatment, limiting the effectiveness of chemotherapy. Mushroom extracts have shown potential as treatments for cancer therapies, offering a possible solution to overcome chemoresistance. This systematic review aimed to explore the role of mushroom extracts in enhancing chemotherapy and reversing chemoresistance in cancer cells. We searched the PubMed, Web of Science and Scopus databases, following the PRISMA guidelines, and registered on PROSPERO. The extracts acted by inhibiting the proliferation of cancer cells, as well as enhancing the effect of chemotherapy. The mechanisms by which they acted included regulating anti-apoptotic proteins, inhibiting the JAK2/STAT3 pathway, inhibiting the ERK1/2 pathway, modulating microRNAs and regulating p-glycoprotein. These results highlight the potential of mushroom extracts to modulate multiple mechanisms in order to improve the efficacy of chemotherapy. This work sheds light on the use of mushroom extracts as an aid to chemotherapy to combat chemoresistance. Although studies are limited, the diversity of mushrooms and their bioactive compounds show promising results for innovative strategies to treat cancer more effectively. It is crucial to carry out further studies to better understand the therapeutic potential of mushroom extracts to improve the efficacy of chemotherapy in cancer cells.

Advances in the variations and biomedical applications of stimuli-responsive nanodrug delivery systems

Chemotherapy is an important cancer treatment modality, but the clinical utility of chemotherapeutics is limited by their toxic side effects, inadequate distribution and insufficient intracellular concentrations. Nanodrug delivery systems (NDDSs) have shown significant advantages in cancer diagnosis and treatment. Variable NDDSs that respond to endogenous and exogenous triggers have attracted much research interest. Here, we summarized nanomaterials commonly used for tumor therapy, such as peptides, liposomes, and carbon nanotubes, as well as the responses of NDDSs to pH, enzymes, magnetic fields, light, and multiple stimuli. Specifically, well-designed NDDSs can change in size or morphology or rupture when induced by one or more stimuli. The varying responses of NDDSs to stimulation contribute to the molecular design and development of novel NDDSs, providing new ideas for improving drug penetration and accumulation, inhibiting tumor resistance and metastasis, and enhancing immunotherapy.

Nanomedicine Combats Drug Resistance in Lung Cancer

Lung cancer is the second most prevalent cancer and the leading cause of cancer-related death worldwide. Surgery, chemotherapy, molecular targeted therapy, immunotherapy, and radiotherapy are currently available as treatment methods. However, drug resistance is a significant factor in the failure of lung cancer treatments. Novel therapeutics have been exploited to address complicated resistance mechanisms of lung cancer and the advancement of nanomedicine is extremely promising in terms of overcoming drug resistance. Nanomedicine equipped with multifunctional and tunable physiochemical properties in alignment with tumor genetic profiles can achieve precise, safe, and effective treatment while minimizing or eradicating drug resistance in cancer. Here, this work reviews the discovered resistance mechanisms for lung cancer chemotherapy, molecular targeted therapy, immunotherapy, and radiotherapy, and outlines novel strategies for the development of nanomedicine against drug resistance. This work focuses on engineering design, customized delivery, current challenges, and clinical translation of nanomedicine in the application of resistant lung cancer.

Targeted drug delivery systems for elemene in cancer therapy: The story thus far

Elemene (ELE) is a group of broad-spectrum anticancer active ingredients with low toxicity extracted from traditional Chinese medicines (TCMs), such as Curcumae Rhizoma and Curcuma Radix, which can exert antitumour activities by regulating various signal pathways and targets. However, the strong hydrophobicity, short half-life, low bioavailability and weak in vivo targeting ability of ELE restrict its use. Targeted drug delivery systems based on nanomaterials are among the most viable methods to overcome these shortcomings. In this review, we first summarize recent studies on the clinical uses of ELE as an adjunct antitumour drug. ELE-based combination strategies have great promise for enhancing efficacy, reducing adverse reactions, and improving patients' quality of life and immune function. Second, we summarize recent studies on the antitumour mechanisms of ELE and ELE-based combination strategies. The potential mechanisms include inducing pyroptosis and ferroptosis, promoting senescence, regulating METTL3-mediated m6A modification, suppressing the Warburg effect, and inducing apoptosis and cell cycle arrest. Most importantly, we comprehensively summarize studies on the combination of targeted drug delivery systems with ELE, including passively and actively targeted drug delivery systems, stimuli-responsive drug delivery systems, and codelivery systems for ELE combined with other therapies, which have great promise in improving drug bioavailability, increasing drug targeting ability, controlling drug release, enhancing drug efficacy, reducing drug adverse effects and reversing MDR. Our summary will provide a reference for the combination of TCMs such as ELE with advanced targeted drug delivery systems in the future.

Natural compounds: Wnt pathway inhibitors with therapeutic potential in lung cancer

The Wnt/β-catenin pathway is abnormally activated in most lung cancer tissues and considered to be an accelerator of carcinogenesis and lung cancer progression, which is closely related to increased morbidity rates, malignant progression, and treatment resistance. Although targeting the canonical Wnt/β-catenin pathway shows significant potential for lung cancer therapy, it still faces challenges owing to its complexity, tumor heterogeneity and wide physiological activity. Therefore, it is necessary to elucidate the role of the abnormal activation of the Wnt/β-catenin pathway in lung cancer progression. Moreover, Wnt inhibitors used in lung cancer clinical trials are expected to break existing therapeutic patterns, although their adverse effects limit the treatment window. This is the first study to summarize the research progress on various compounds, including natural products and derivatives, that target the canonical Wnt pathway in lung cancer to develop safer and more targeted drugs or alternatives. Various natural products have been found to inhibit Wnt/β-catenin in various ways, such as through upstream and downstream intervention pathways, and have shown encouraging preclinical anti-tumor efficacy. Their diversity and low toxicity make them a popular research topic, laying the foundation for further combination therapies and drug development.

Dual-drug codelivery nanosystems: An emerging approach for overcoming cancer multidrug resistance

Multidrug resistance (MDR) promotes tumor recurrence and metastasis and heavily reduces anticancer efficiency, which has become a primary reason for the failure of clinical chemotherapy. The mechanisms of MDR are so complex that conventional chemotherapy usually fails to achieve an ideal therapeutic effect and even accelerates the occurrence of MDR. In contrast, the combination of chemotherapy with dual-drug has significant advantages in tumor therapy. A novel dual-drug codelivery nanosystem, which combines dual-drug administration with nanotechnology, can overcome the application limitation of free drugs. Both the characteristics of nanoparticles and the synergistic effect of dual drugs contribute to circumventing various drug-resistant mechanisms in tumor cells. Therefore, developing dual-drug codelivery nanosystems with different multidrug-resistant mechanisms has an important reference value for reversing MDR and enhancing the clinical antitumor effect. In this review, the advantages, principles, and common codelivery nanocarriers in the application of dual-drug codelivery systems are summarized. The molecular mechanisms of MDR and the dual-drug codelivery nanosystems designed based on different mechanisms are mainly introduced. Meanwhile, the development prospects and challenges of codelivery nanosystems are also discussed, which provide guidelines to exploit optimized combined chemotherapy strategies in the future.

Multistage O2-producing liposome for MRI-guided synergistic chemodynamic/chemotherapy to reverse cancer multidrug resistance

Reduced drug uptake and elevated drug efflux are two major mechanisms in cancer multidrug resistance (MDR). In the present study, a new multistage O₂-producing liposome with NAG/R8-dual-ligand and stimuli-responsive dePEGylation was developed to address the abovementioned issues simultaneously. The designed C-NAG-R8-PTXL/MnO₂-lip could also achieve magnetic resonance imaging (MRI)-guided synergistic chemodynamic/chemotherapy (CDT/CT). In vitro and in vivo studies showed that C-NAG-R8-PTXL/MnO₂-lip enhanced circulation time by PEG and targeted the tumor site. After tumor accumulation, endogenous l-cysteine was administered, and the PEG-attached disulfide bond was broken, resulting in the dissociation of PEG shells. The previously hidden positively charged R8 by different lengths of PEG chains was exposed and mediated efficient internalization. In addition, the oxygen (O₂) generated by C-NAG-R8-PTXL/MnO₂-lip relieved the hypoxic environment within the tumor, thus reducing the efflux of chemotherapeutic drug. O₂ was able to burst liposomes and triggered the release of PTXL. The toxic hydroxyl radical (·OH), which was produced by H₂O₂ and Mn²⁺, strengthened CDT/CT. C-NAG-R8-PTXL/MnO₂-lip was also used as MRI contrast agent, which blazed the trail to rationally design theranostic agents for tumor imaging.

Natural Compounds in Liposomal Nanoformulations of Potential Clinical Application in Glioblastoma

Glioblastoma (GBM) is the most common malignant neoplasm in adults among all CNS gliomas, with the 5-year survival rate being as low as 5%. Among nanocarriers, liposomal nanoformulations are considered as a promising tool for precise drug delivery. The herein presented study demonstrates the possibility of encapsulating four selected natural compounds (curcumin, bisdemethoxycurcumin, acteoside, and orientin) and their mixtures in cationic liposomal nanoformulation composed of two lipid types (DOTAP:POPC). In order to determine the physicochemical properties of the new drug carriers, specific measurements, including particle size, Zeta Potential, and PDI index, were applied. In addition, NMR and EPR studies were carried out for a more in-depth characterization of nanoparticles. Within biological research, the prepared formulations were evaluated on T98G and U-138 MG glioblastoma cell lines in vitro, as well as on a non-cancerous human lung fibroblast cell line (MRC-5) using the MTT test to determine their potential as anticancer agents. The highest activity was exhibited by liposome-entrapped acteoside towards the T98G cell line with IC₅₀ equal 2.9 ± 0.9 µM after 24 hours of incubation. Noteworthy, curcumin and orientin mixture in liposomal formulation exhibited a synergistic effect against GBM. Moreover, the impact on the expression of apoptosis-associated proteins (p53 and Caspase-3) of acteoside as well as curcumin and orientin mixture, as the most potent agents, was assessed, showing nearly 40% increase as compared to control U-138 MG and T98G cells. It should be emphasized that a new and alternative method of extrusion of the studied liposomes was developed.

Co-Delivery System of Curcumin and Colchicine Using Functionalized Mesoporous Silica Nanoparticles Promotes Anticancer and Apoptosis Effects

Purpose: Many natural agents have a high anticancer potential, and their combination may be advantageous for improved anticancer effects. Such agents, however, often are not water soluble and do not efficiently target cancer cells, and the kinetics of their action is poorly controlled. One way to overcome these barriers is to combine natural agents with nanoparticles. Our aim in the current study was to fabricate an anticancer nanoformulation for co-delivery of two natural agents, curcumin (CR) and colchicine (CL), with a core-shell structure. Using cancer cell lines, we compared the anticancer efficacy between the combination and a nanoformulation with CL alone. Methods: For the single-drug nanoformulation, we used phosphonate groups to functionalize mesoporous silica nanoparticles (MSNs) and loaded the MSNs with CL. Additional loading of this nanoformulation with CR achieved the co-delivery format. To create the structure with a core shell, we selected a chitosan−cellulose mixture conjugated with targeting ligands of folic acid for the coating. For evaluating anticancer and apoptosis effects, we assessed changes in important genes and proteins in apoptosis (p53, caspase-3, Bax, Bcl-2) in several cell lines (MCF-7, breast adenocarcinoma; HCT-116, colon carcinoma; HOS, human osteosarcoma; and A-549, non−small cell lung cancer). Results: Nanoformulations were successfully synthesized and contained 10.9 wt.% for the CL single-delivery version and 18.1 wt.% for the CL+CR co-delivery nanoformulation. Anticancer effects depended on treatment, cell line, and concentration. Co-delivery nanoformulations exerted anticancer effects that were significantly superior to those of single delivery or free CL or CR. Anticancer effects by cell line were in the order of HCT-116 > A549 > HOS > MCF-7. The lowest IC50 value was obtained for the nanoformulation consisting of CL and CR coated with a polymeric shell conjugated with FA (equivalent to 4.1 ± 0.05 µg/mL). With dual delivery compared with the free agents, we detected strongly increased p53, caspase-3, and Bax expression, but inhibition of Bcl-2, suggesting promotion of apoptosis. Conclusions: Our findings, although preliminary, indicate that the proposed dual delivery nanoformulation consisting of nanocore: MSNs loaded with CL and CR and coated with a shell of chitosan−cellulose conjugated folic acid exerted strong anticancer and apoptotic effects with potent antitumor activity against HCT-116 colon cells. The effect bested CL alone. Evaluating and confirming the efficacy of co-delivery nanoformulations will require in vivo studies.

Ignored role of polyphenol in boosting reactive oxygen species generation for polyphenol/chemodynamic combination therapy

Chemodynamic therapy (CDT) is a promising tumor-specific treatment, but still suffering insufficient reactive oxygen species (ROS) levels due to its limited efficacy of Fenton/Fenton-like reaction. Polyphenol, as a natural reductant, has been applied to promote the efficacy of Fenton/Fenton-like reactions; however, its intrinsic pro-apoptosis effects was ignored. Herein, a novel CDT/polyphenol-combined strategy was designed, based on Avenanthramide C-loaded dendritic mesoporous silica (DMSN)-Au/Fe₃O₄ nanoplatforms with folic acid modification for tumor-site targeting. For the first time, we showed that the nanocomplex (DMSNAF-AVC-FA) induced ROS production in the cytoplasm via Au/Fe₃O₄-mediated Fenton reactions and externally damaged the mitochondrial membrane; simultaneously, the resultant increased mitochondrial membrane permeability can facilitate the migration of AVC into mitochondrial, targeting the DDX3 pathway and impairing the electron transport chain (ETC) complexes, which significantly boosted the endogenous ROS levels inside the mitochondrial. Under the elevated oxidative stress level via both intra- and extra-mitochondrial ROS production, the maximum mitochondrial membrane permeability was achieved by up-regulation of Bax/Bcl-2, and thereby led to massive release of Cytochrome C and maximum tumor cell apoptosis via Caspase-3 pathway. As a result, the as-designed strategy achieved synergistic cytotoxicity to 4T1 tumor cells with the cell apoptosis rate of 99.12% in vitro and the tumor growth inhibition rate of 63.3% in vivo, while very minor cytotoxicity to normal cells with cell viability of 95.4%. This work evidenced that natural bioactive compounds are powerful for synergistically boosting ROS level, providing new insight for accelerating the clinical conversion progress of CDT with minimal side effects.

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A novel CDT/polyphenol-combined nanoplatform, DMSNAF-AVC-FA was designed.

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DMSNAF-AVC-FA induced ROS production and externally damaged mitochondrial membrane.

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DMSNAF-AVC-FA facilitated AVC targeting the DDX3 pathway and impairing ETC complexes.

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DMSNAF-AVC-FA achieved synergistic antitumor efficacy both in vitro and in vivo.

A novel ligand-modified nanocomposite microparticles improved efficiency of quercetin and paclitaxel delivery in the non-small cell lung cancer

Chemotherapy is the first choice for the treatment of cancer but it is still limited by insufficient kill efficiency and drug resistance. These problems urgently need to be overcome in a way that minimizes damage to the body. In this study, we designed the nanocomposite microparticles (NMPs) modified by cetuximab (Cet) and loaded anti-tumor agents- quercetin (QUE) and paclitaxel (PTX)- for eliciting specific drugs homing and enhancing the killing efficiency of chemotherapy drugs (P/Q@CNMPs). Physicochemical characteristics results presented that P/Q@CNMPs have a suitable aerodynamic diameter and uniform morphology that could meet the requirements of particles deposition in the lung. And it also had the characteristics of sustained-release and pH-responsive which could release the agents in the right place and has a continuous effect. In vitro and in vivo analysis results presented that P/Q@CNMPs have the accuracy targeting ability and killing effect on non-small cell lung cancer (NSCLC) which express positive epidermal growth factor receptor (EGFR) on the membrane. Furthermore, this system also has low toxicity and good biocompatibility. These results demonstrated that P/Q@CNMPs could be a potential intelligent targeting strategy used for chemo-resistant NSCLC therapies.

Remodeling tumor microenvironment with natural products to overcome drug resistance

With cancer incidence rates continuing to increase and occurrence of resistance in drug treatment, there is a pressing demand to find safer and more effective anticancer strategy for cancer patients. Natural products, have the advantage of low toxicity and multiple action targets, are always used in the treatment of cancer prevention in early stage and cancer supplement in late stage. Tumor microenvironment is necessary for cancer cells to survive and progression, and immune activation is a vital means for the tumor microenvironment to eliminate cancer cells. A number of studies have found that various natural products could target and regulate immune cells such as T cells, macrophages, mast cells as well as inflammatory cytokines in the tumor microenvironment. Natural products tuning the tumor microenvironment via various mechanisms to activate the immune response have immeasurable potential for cancer immunotherapy. In this review, it highlights the research findings related to natural products regulating immune responses against cancer, especially reveals the possibility of utilizing natural products to remodel the tumor microenvironment to overcome drug resistance.

Multifunctional nanomedicine strategies to manage brain diseases

Brain diseases represent a substantial social and economic burden, currently affecting one in six individuals worldwide. Brain research has been focus of great attention in order to unravel the pathogenesis and complexity of brain diseases at the cellular, molecular, and microenvironmental levels. Due to the intrinsic nature of the brain, the presence of the highly restrictive blood-brain barrier (BBB), and the pathophysiology of most diseases, therapies can hardly be considered successful purely by the administration of one drug to a patient. Apart from improving pharmacokinetic parameters, tailoring biodistribution, and reducing the number of side effects, nanomedicines are able to actively co-target the therapeutics to the brain parenchyma and brain lesions, as well as to achieve the delivery of multiple cargos with therapeutic, diagnostic, and theranostic properties. Among other multivalent effects that can be personalized according to the disease needs, this represents a promising class of novel nanosystems, termed multifunctional nanomedicines. Herein, we review the principal mechanisms of therapeutic resistance of the most prevalent brain diseases, how to overcome this therapeutic resistance through the use of multifunctional nanomedicines that tackle multiple fronts of the disease microenvironment, and the promising therapeutic responses achieved by some of the most cutting-edge multifunctional nanomedicines reported in literature.

Paeonol Protects against Methotrexate Hepatotoxicity by Repressing Oxidative Stress, Inflammation, and Apoptosis-The Role of Drug Efflux Transporters

Methotrexate (MTX) is an effective chemotherapeutic agent against a wide range of tumors and autoimmune diseases; however, hepatotoxicity limits its clinical use. Oxidative stress and inflammation have been implicated in the pathogenesis of MTX-induced hepatotoxicity. Paeonol is a natural phenolic compound reported for its antioxidant and anti-inflammatory properties. The current study aimed to investigate the protective effect of paeonol against MTX-induced hepatotoxicity in rats and various mechanisms that underlie this postulated effect. Paeonol was administered orally in a dose of 100 mg/kg, alone or along with MTX, for 10 days. Hepatotoxicity was induced via a single intraperitoneal dose of MTX (20 mg/kg) on day 5 of the experiment. Concomitant administration of paeonol with MTX significantly ameliorated distorted hepatic function and histological structure, restored hepatic oxidative stress parameters (MDA, NO, and SOD), and combated inflammatory response (iNOS and TNF-α). Additionally, paeonol enhanced cell proliferation and survival, evidenced by upregulating the proliferating cell nuclear antigen (PCNA) and suppressing apoptosis and the disposition of collagen fibers in rat livers treated with MTX. Importantly, paeonol upregulated the drug efflux transporters, namely P-glycoprotein (P-gp) and the multidrug resistance-associated protein 2 (Mrp-2) in MTX-treated rats. In conclusion, paeonol offered a potent protective effect against MTX-induced hepatotoxicity through suppressing oxidative stress, inflammation, fibrosis, and apoptosis pathways, along with P-gp and Mrp-2 upregulation.

The Current State of the Art in PARP Inhibitor-Based Delivery Nanosystems

Poly (adenosine diphosphate [ADP]–ribose) polymerases inhibitors (PARPi), the first clinically approved drug that exhibits synthetic lethality, are moving to the forefront of cancer treatments. Currently, the oral bioavailability of PARPi is quite low; thus, it is a major challenge to effectively and safely deliver PARPi during clinical cancer therapy. Nanotechnology has greatly advanced the development of drug delivery. Based on the basic characteristics and various forms of nanoparticles, drug delivery systems can prolong the time that drugs circulate, realize the controlled release of drugs, provide drugs with an active targeting ability, and spatiotemporally present combination treatment. Furthermore, nanosystems may not only enhance drug efficiency but also reduce adverse side effects. This review focuses on strategies involving nanoparticle-based delivery for PARPi, including single administration and codelivery with other agents. We believe that nanosystems have great potential in advancing PARPi efficacy for cancer therapy.

Nanoarchitectured Graphene Organic Framework for Drug Delivery and Chemo-photothermal Synergistic Therapy

The combination of phototherapy and chemotherapy has received extensive attention in the field of cancer therapy. Hence, graphene organic framework (GOF) with a large d-spacing was prepared by solvothermal method, and a novel nanocomposite based on bovine serum albumin (BSA) and the anticancer drug doxorubicin (DOX) was developed, which effectively achieved a photothermal-chemotherapy synergistic treatment. When the feeding ratio was 1:1.6, the DOX loading capacity was 18.51%, and the GOF-BSA/DOX nanocomposite possessed unobvious pH response characteristic, as well as the cumulative release of DOX reached 54.17% at 42°C in the acidic environment (pH = 5.0). The nanocarriers also showed excellent photothermal property and photothermal stability in vitro. In addition, under 808 nm near-infrared laser (NIR) irradiation, the GOF-BSA/DOX nanocomposites generated a large amount of heat, which significantly enhanced the synergistic antitumor effect of in vitro photothermal-chemotherapy. Furthermore, the GOF-BSA/DOX nanocomposites exhibited significantly increased cytotoxicity in the NIR compared with chemotherapy or photothermal therapy alone, suggesting that the combination of chemotherapy and photothermal therapy has excellent antitumor capacity. Therefore, porous GOF nanocarriers may have great potential in combined anti-tumour therapy.

Synergistic co-administration of docetaxel and curcumin to chemoresistant cancer cells using PEGylated and RIPL peptide-conjugated nanostructured lipid carriers

Background

A targeted co-administration system of docetaxel (DTX) and curcumin (CUR) using a PEG-modified RIPL peptide (IPLVVPLRRRRRRRRC)-conjugated nanostructured lipid carrier (P/R-NLC) was constructed to exert synergistic anticancer effects against chemoresistant breast cancer.

Results

DTX- or CUR-loaded NLCs and P/R-NLCs were prepared using the solvent emulsification–evaporation method. NLCs showed homogeneous spherical morphology with nano-sized dispersion (< 210 nm) with zeta potential varying from − 16.4 to − 19.9 mV. DTX or CUR was successfully encapsulated in the NLCs: encapsulation efficiency (> 95%); drug loading (8 − 18%). All NLC formulations were stable for 4 weeks under the storage conditions at 4 °C. Drug release was diffusion-controlled, revealing the best fit to the Higuchi equation. DTX- or CUR-loaded formulations showed dose-dependent cytotoxicity. The DTX/CUR combination (1:3 w/w) in P/R-NLC formulations exhibited the strongest synergism in both MCF7 and MCF7/ADR cells with combination index values of 0.286 and 0.130, respectively. Co-treatment with DTX- or CUR-P/R-NLCs increased apoptosis in both cell lines exhibited the superior synergistic inhibitory effect on MCF7/ADR three-dimensional spheroids. Finally, in OVCAR3-xenografted mouse models, co-treatment with DTX- or CUR-loaded P/R-NLCs significantly suppressed tumor growth compared to the other treatment groups.

Conclusions

Co-administration of DTX/CUR (1:3 w/w) using P/R-NLCs induced a synergistic effect against chemoresistant cancer cells.

Graphical Abstract

Atractylodin Induces Apoptosis and Inhibits the Migration of A549 Lung Cancer Cells by Regulating ROS-Mediated Signaling Pathways

Atractylodin (ATR) has anticancer effects on some tumor cells by inducing apoptosis, but its mechanism in lung cancer remains unclear. This study investigates the inhibitory effect of ATR on A549 lung cancer cells. Cell viability was detected by the Cell Counting Kit-8 assay, and results showed that ATR could significantly inhibit the proliferation of A549 cells. Apoptosis was detected by Annexin V-FITC/PI staining, and apoptosis rate and mitochondrial membrane potential were detected by flow cytometry. Results showed that the effect of ATR on the apoptosis of A549 cells was negatively correlated with the change in mitochondrial membrane potential. Western blot analysis showed that ATR regulated apoptosis induced by mitogen-activated protein kinase, signal transducer and activator of transcription 3, and nuclear factor kappa B signaling pathways. Analyses of reactive oxygen species (ROS), cell cycle, and cell migration showed that ATR induced intracellular ROS accumulation as an initiation signal to induce cell cycle arrest regulated by the AKT signaling pathway and cell migration inhibition regulated by the Wnt signaling pathway. Results showed that ATR can inhibit cell proliferation, induce cell apoptosis, induce cell cycle arrest, and inhibit the migration of A549 cells (p < 0.05 was considered statistically significant, * p < 0.05, ** p < 0.01 and *** p < 0.001).

Reptiles as Promising Sources of Medicinal Natural Products for Cancer Therapeutic Drugs

Natural products have historically played an important role as a source of therapeutic drugs for various diseases, and the development of medicinal natural products is still a field with high potential. Although diverse drugs have been developed for incurable diseases for several decades, discovering safe and efficient anticancer drugs remains a formidable challenge. Reptiles, as one source of Asian traditional medicines, are known to possess anticancer properties and have been used for a long time without a clarified scientific background. Recently, it has been reported that extracts, crude peptides, sera, and venom isolated from reptiles could effectively inhibit the survival and proliferation of various cancer cells. In this article, we summarize recent studies applying ingredients derived from reptiles in cancer therapy and discuss the difficulties and prospective development of natural product research.

Edible plant-derived nanotherapeutics and nanocarriers: recent progress and future directions

INTRODUCTION

High drug delivery efficiency, desirable therapeutic effects, and low toxicity have become crucial to develop nanotherapeutics. Natural nanoparticles (NPs) from edible plants contain a large quantity of bioactive small molecules, proteins, glycolipids, and microRNAs. The development of these NPs has rapidly attracted increasing attention due to their merits of green production, excellent biocompatibility, anti-inflammatory activities, and antitumor capacities.

AREAS COVERED

Here, we introduce the extraction, purification, and construction strategies of plant-derived exosome-like NPs (PDENs) and expound on their physicochemical properties, biomedical functions, and therapeutic effects against various diseases. We also recapitulate future directions and challenges of the emerging nanotherapeutics.

EXPERT OPINION

PDENs have been used as natural nanotherapeutics and nanocarriers. The challenges of applying PDENs primarily stem from the lack of understanding of the mechanisms that drive the tissue-specific targeting properties. Elucidating the underlying targeting mechanisms is one of the major focuses in this review, which helps to gain new research opportunities for the development of natural nanotherapeutics. Despite excellent biosafety and therapeutic effects in the treatment of various diseases, the medical translation of these NPs has still been limited by low yields and cold-chain dependence. Therefore, exploiting new techniques will be required for their massive production and storage.

Self-Rectifiable and Hypoxia-Assisted Chemo-Photodynamic Nanoinhibitor for Synergistic Cancer Therapy

Photodynamic therapy (PDT) can eradicate cancer cells under light irradiation, mainly because of reactive singlet oxygen (¹O₂) being transformed from intratumoral oxygen. Nonetheless, the consumption of oxygen during PDT results in serious hypoxic conditions and an elevated hypoxia-inducing factor-1α (HIF-1α) level that hamper further photodynamic efficacy and induce tumor metastasis. To address this problem, we developed hypoxia-assisted NP-co-encapsulating Ce6 (photosensitizer) and YC-1 (HIF-1α inhibitor) as a self-rectifiable nanoinhibitor for synergistic antitumor treatment. PDT-aggravated intracellular hypoxic stress facilitated NP dissociation to release the drug (YC-1), which achieved tumor killing and HIF-1α inhibition to further enhance the therapeutic effect of PDT and prevent tumor metastasis. Besides, in vivo studies revealed that the HC/PI@YC-1 NPs afforded synergistic anticancer efficacy with minimal toxicity. Therefore, this study provides a prospective approach against PDT drawbacks and combination cancer therapy.

Diterpenoids from Euphorbia glomerulans with potential reversal activities against P-glycoprotein-mediated multidrug resistance

The development of collateral sensitivity agents that are able to modulate P-glycoprotein (P-gp) is the most promising approaches to overcome multidrug resistance (MDR) in cancer. In this study, eight new diterpenoids of jatrophane and ingenane type, 1-8, and three known ones (9-11) were isolated from Euphorbia glomerulans. Their structures were elucidated by spectroscopic analysis and electronic circular dichroism (ECD) calculations. The MDR reversal activity evaluation of these isolates on breast cancer MCF-7/ADR cells demonstrated the four potent MDR modulators (3, 4, 5, and 9) with great chemoreversal ability and low cytotoxicity. The structure-activity relationship (SAR) analysis indicated that the presence of isobutanoyloxy group at C-8 significantly enhance reversal efficiency. Compound 5 exhibited high efficacy (EC₅₀ = 159.5 nM) in reversing MDR resistance, being stronger than verapamil (EC₅₀ = 302.9 nM). The MDR reversal mechanism assays revealed that 5 could promote the accumulation of Rh123 and DOX in drug-resistant cells in a certain dose-dependent manner, and inhibit P-gp transport function. In addition, the possible recognition mechanism of compound 5 and verapamil (VRP) with P-gp was predicted by molecular docking.