Synergistically Enhanced Antimetastasis Effects by Honokiol-Loaded pH-Sensitive Polymer-Doxorubicin Conjugate Micelles

Design of self-assembled micelles based on natural dual-targeting strategies and evaluation of their anti-liver cancer effects as drug delivery systems

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors in the world and in China, Most patients are already in an advanced stage at the time of diagnosis, and the chance of complete surgical resection is lost, therefore, drug treatment is particularly important. Angelica sinensis polysaccharide (ASP) has natural liver-targeting properties, berberine (BBR) is a lipophilic cation with anticancer activities and mitochondrial-targeting properties, and honokiol (HNK) has mitochondria-dependent anticancer effects against cancer. Therefore, the aim of the present work was to synthesize Angelica sinensis polysaccharide-berberineamphiphilic polymer (ASP-SS-BBR) loaded with HNK to prepare the micelles ASP-BBR-PM@HNK to improve the hepatic targeting ability of the nanoparticles and the mitochondrial targeting ability in HCC cells and to enhance the anti-HCC effect of HNK. The findings of this study demonstrate the successful synthesis of ASP-BBR-PM@HNK, characterized by a particle size of 48.6 ± 1.13 nm. The formulation exhibits commendable stability, a sustained-release profile, and the capability for glutathione (GSH)-responsive release. ASP-BBR-PM@HNK is efficiently internalized by HepG2 cells, exhibiting the highest rate of cell inhibition. Additionally, the use of Gal and Man as receptor blockers confirmed the formulation's superior targeting capabilities, including exceptional mitochondrial targeting. Subsequent in vivo experiments employing BALB/c nude mice as a model further corroborated these experimental outcomes. This research has successfully developed an effective natural dual-targeting system, offering a novel approach for the precise treatment of liver cancer.

Bioorthogonal Chemistry-Guided Inhalable Nanoprodrug to Circumvent Cisplatin Resistance in Orthotopic Nonsmall Cell Lung Cancer

Pulmonary delivery of anticancer therapeutics has shown encouraging performance in treating nonsmall cell lung cancer (NSCLC), which is characterized by high aggressiveness and poor prognosis. Cisplatin, a key member of the family of DNA alkylating agents, is extensively employed during NSCLC therapy. However, the development of chemoresistance and the occurrence of side effects severely impede the long-term application of cisplatin-based chemotherapies. Herein, we propose a meaningful strategy to precisely treat cisplatin-resistant NSCLC based on the combination of bioorthogonal chemistry with an inhalation approach. Ethacraplatin (EA-Pt), a platinum prodrug (IV), was synthesized and encapsulated in nitric oxide (NO)-containing micelles to overcome cisplatin chemoresistance. By further modifying bioorthogonal molecules in this nanoplatform (EA-Pt@MDBCO), an improved targeting performance toward pulmonary cancerous regions is achieved after prelabeling with azide via inhalation. Upon entering acidic cancer cells, EA-Pt is swiftly released due to the pH sensitivity of bioorthogonal micelles, which enables its bifunctions to inhibit glutathione S-transferase activity and deplete intracellular glutathione, eventually reversing cisplatin resistance. Moreover, the released NO also improves the overall therapeutic outcome against NSCLC. Consequently, inhalable EA-Pt@MDBCO prelabeled by azide effectively inhibits the progression of cisplatin-resistant orthotopic NSCLC, offering a feasible nanostrategy to expand the treatment options for NSCLC.

A chitosan-camouflaged nanomedicine triggered by hierarchically stimuli to release drug for multimodal imaging-guided chemotherapy of breast cancer

Breast cancer remains one of the most intractable diseases, especially the malignant form of metastasis, with which the cancer cells are hard to track and eliminate. Herein, the common known carbohydrate polymer chitosan (CS) was innovatively used as a shelter for the potent tumor-killing agent. The designed nanoparticles (NPs) not only enhance the solubility of hydrophobic paclitaxel (PTX), but also provide a "hide" effect for cytotoxic PTX in physiological condition. Moreover, coupled with the photothermal (PTT) properties of MoS2, results in a potent chemo/PTT platform. The MoS2@PTX-CS-K237 NPs have a uniform size (135 ± 17 nm), potent photothermal properties (η = 31.5 %), and environment-responsive (low pH, hypoxia) and near infrared (NIR) laser irradiation-triggered PTX release. Through a series of in vitro and in vivo experiments, the MoS2@PTX-CS-K237 showed high affinity and specificity for breast cancer cells, impressive tumor killing capacity, as well as the effective inhibitory effect of metastasis. Benefit from the unique optical properties of MoS2, this multifunctional nanomedicine also exhibited favorable thermal/PA/CT multimodality imaging effect on tumor-bearing mice. The system developed in this work represents the advanced design concept of hierarchical stimulus responsive drug release, and merits further investigation as a potential nanotheranostic platform for clinical translation.

The Anticancer Application of Delivery Systems for Honokiol and Magnolol

Cancer is a leading cause of death worldwide, and the effectiveness of treatment is consistently not at a satisfactory level. This review thoroughly examines the present knowledge and perspectives of honokiol (HON) in cancer therapeutics. The paper synthesizes critical insights into the molecular mechanisms underlying the observed anticancer effects, emphasizing both in vitro and in vivo studies. The effects of HON application, primarily in the common types of cancers, are presented. Because the therapeutic potential of HON may be limited by its physicochemical properties, appropriate delivery systems are sought to overcome this problem. This review discusses the effect of different nanotechnology-based delivery systems on the efficiency of HON. The data presented show that HON exhibits anticancer effects and can be successfully administered to the site of action. Honokiol exerts its anticancer activity through several mechanisms. Moreover, some authors used the combinations of classical anticancer drugs with HON. Such an approach is very interesting and worth further investigation. Understanding HON's multiple molecular mechanisms would provide valuable insights into how HON might be developed as an effective therapeutic. Therefore, further research is needed to explore its specific applications and optimize its efficacy in diverse cancer types.

Upregulation of tumor suppressor PIAS3 by Honokiol promotes tumor cell apoptosis via selective inhibition of STAT3 tyrosine 705 phosphorylation

The natural product Honokiol exhibits robust antitumor activity against a range of cancers, and it has also received approval to undergo phase I clinical trial testing. We confrmed that honokiol can promote the apoptotic death of tumor cells through cell experiments. Then siRNA constructs specific for PIAS3, PIAS3 overexpression plasmid and the mutation of the STAT3 Tyr705 residue were used to confirm the mechanism of Honokiol-induced apoptosis. Finally, we confrmed that honokiol can promote PIAS3 upregulation, in turn suppressing STAT3 Tyr705 phosphorylation through the in vivo and in vitro experiments. Honokiol was ultimately found to reduce tumor cell viability by promoting apoptosis through a mechanism dependent on the ability of Honokiol to promote PIAS3 upregulation and the selective inhibition of p-STAT3 (Tyr705) without affecting p-STAT3 (Ser727) or p-STAT1 (Tyr701) levels. PIAS3 knockdown and overexpression in tumor cells altered STAT3 activation and associated DNA binding activity through the control of Tyr705 phosphorylation via PIAS3-STAT3 complex formation, ultimately shaping Honokiol-induced tumor cell apoptosis. Honokiol was also confirmed to significantly prolong the survival of mice bearing xenograft tumors in a PIAS3-dependent fashion. Together, these findings highlight a novel pathway through which Honokiol can promote PIAS3 upregulation, in turn suppressing STAT3 Tyr705 phosphorylation and promoting the apoptotic death of tumor cells.

Nanotechnology-Based Drug Delivery Systems for Honokiol: Enhancing Therapeutic Potential and Overcoming Limitations

Honokiol (HNK) is a small-molecule polyphenol that has garnered considerable attention due to its diverse pharmacological properties, including antitumor, anti-inflammatory, anti-bacterial, and anti-obesity effects. However, its clinical application is restricted by challenges such as low solubility, poor bioavailability, and rapid metabolism. To overcome these limitations, researchers have developed a variety of nano-formulations for HNK delivery. These nano-formulations offer advantages such as enhanced solubility, improved bioavailability, extended circulation time, and targeted drug delivery. However, existing reviews of HNK primarily focus on its clinical and pharmacological features, leaving a gap in the comprehensive evaluation of HNK delivery systems based on nanotechnology. This paper aims to bridge this gap by comprehensively reviewing different types of nanomaterials used for HNK delivery over the past 15 years. These materials encompass vesicle delivery systems, nanoparticles, polymer micelles, nanogels, and various other nanocarriers. The paper details various HNK nano-delivery strategies and summarizes their latest applications, development prospects, and future challenges. To compile this review, we conducted an extensive search using keywords such as "honokiol", "nanotechnology", and "drug delivery system" on reputable databases, including PubMed, Scopus, and Web of Science, covering the period from 2008 to 2023. Through this search, we identified and selected approximately 90 articles that met our specific criteria.

Spermine-Based Poly(β-amino ester)s for siRNA Delivery against Mutated KRAS in Lung Cancer

Polyethylenimine (PEI) is a highly efficient cationic polymer for nucleic acid delivery, and although it is commonly used in preclinical studies, its clinical application is limited because of concerns regarding its cytotoxicity. Poly(β-amino ester)s are a new group of biodegradable and biocompatible cationic polymers that can be used for siRNA delivery. In this study, we synthesized Boc-protected and deprotected poly(β-amino ester)s, P(BSpBAE) and P(SpBAE), respectively, based on spermine and 1,4-butanediol diacrylate to deliver siRNA. The polymers were synthesized by Michael addition in a step-growth polymerization and characterized via 1H NMR spectroscopy and size-exclusion chromatography (SEC). The polymers can encapsulate siRNA as determined by SYBR gold assays. Both polymers and polyplexes were biocompatible in vitro. Furthermore, the cellular uptake of P(BSpBAE) and P(SpBAE) polyplexes was more efficient than for branched PEI (25 kDa) polyplexes at the same N/P ratios. P(BSpBAE) polyplexes achieved 60% eGFP knockdown in vitro, which indicates that the Boc-protection can improve the siRNA delivery and gene silencing efficiency of PBAEs. P(BSpBAE) polyplexes and P(SpBAE) polyplexes showed different cellular uptake mechanisms, and P(BSpBAE) polyplexes demonstrated decreased endosomal entrapment, which could explain why P(BSpBAE) polyplexes more efficiently mediated gene silencing than P(SpBAE) polyplexes. Furthermore, transfection of an siRNA against mutated KRAS in KRAS-mutated lung cancer cells led to around 35% (P(BspBAE)) to 45% (P(SpBAE)) inhibition of KRAS expression and around 33% (P(SpBAE)) to 55% (P(BspBAE)) decreased motility in a migration assay. These results suggest that the newly developed spermine-based poly(β-amino ester)s are promising materials for therapeutic siRNA delivery.

Polymeric photothermal nanoplatform with the inhibition of aquaporin 3 for anti-metastasis therapy of breast cancer

Metastasis, as one of major challenges in the cancer treatment, is responsible for the high mortality of breast cancer. It has been reported that breast cancer cell invasion and metastasis are related to aquaporin 3 (AQP3), which is the transmembrane transport channel for H₂O₂ molecules. Moreover, there is agreement that preventing the metastasis of breast tumor cells in combination with inhibiting the tumor growth is a promising strategy for cancer chemotherapy. Herein, we constructed a flexible photothermal crosslinked polymeric nanovehicle for the delivery of the AQP3 inhibitor, [AuCl₂(phen)]⁺Cl^- (Auphen). The polymeric nanovehicle (pOMPC-Dex) is comprised of three modules: 1) pOEGMA-co-pMEO₂MA serves as the temperature-responsive segment; 2) pCyanineMA acts as the near-infrared (NIR) optical absorbing motif for photothermal therapy and is conjugated with pOEGMA-co-pMEO₂MA to obtain NIR light stimuli-responsive drug release; and 3) pPBAMA-Dex functions as an acidic tumor microenvironment-responsive unit. Auphen was encapsulated into a nanovehicle (Auphen@pOMPC-Dex) through electrostatic interactions. The designed nanoplatform showed a pH- and NIR light stimuli-responsive drug release profile and exhibited the strong inhibition of intracellular H₂O₂ uptake by breast cancer cells, which led to the inhibition of breast cancer cell migration and invasion in vitro. In a breast cancer mouse model, Auphen@pOMPC-Dex markedly reduced the number of lung metastases in tumor-bearing mice due to the combined suppression of tumor growth and metastasis. Consequently, the fabricated Auphen@pOMPC-Dex may provide a new strategy for the development of comprehensive oncotherapies. STATEMENT OF SIGNIFICANCE: High mortality due to metastasis-induced breast cancer has been a key issue that needs to be addressed. It has been reported that aquaporin 3 (AQP3), a transmembrane transport channel for H₂O₂ molecules was found to have an accelerated effect on breast cancer cell migration. Hence, a flexible crosslinked polymeric nanoplatform with the inhibition of AQP3 was designed to inhibit metastasis of breast cancer cells. At the same time, we combined suppression of tumor growth with photothermal therapy to enhance the anticancer therapy effect.

Oxidation and Reduction Dual-Responsive Polymeric Prodrug Micelles Co-delivery Precisely Prescribed Paclitaxel and Honokiol for Laryngeal Carcinoma Combination Therapy

Laryngeal carcinoma is the most common head and neck malignancy globally, and chemotherapy is still the most common treatment for this type of carcinoma. Monotherapy has become powerless because of the lack of drugs in the anticancer agent library, the difficult process of new drug discovery, and the widespread drug resistance. Combination therapy with two agents, in particular Chinese herbal medicines with chemotherapy drugs, is a potential alternative to chemotherapy alone. However, combination therapy faces difficulties in delivering multiple drugs to tumor tissue in a precise ratio. Here, a cocktail polymeric prodrug micelle (PHPPM) was developed using an oxidation and reduction dual-responsive polymeric paclitaxel (PTX) and polymeric honokiol (HK) prodrugs. Both of them were obtained by covalently conjugating the drug to dextran via diselenium bonds. Following optimization and characterization, the PHPPM with the precise mass ratio of PTX and HK was obtained, enabling ratiometric drug loading, synchronized drug release in response to tumor high-level reactive oxygen species and glutathione environment, long blood circulation, and high tumor accumulation. This co-delivery system can effectively inhibit laryngeal carcinoma growth in vitro and in vivo. Codelivery of chemotherapy agents and Chinese herbal medicine with a precise ratio and controlled release of the two drugs at the tumor site provides an effective approach to clinical therapy for other laryngeal carcinomas.

Tumor-targeted delivery of honokiol via polysialic acid modified zein nanoparticles prevents breast cancer progression and metastasis

In this work, we developed polysialic acid (PSA) modified zein nanoparticles for targeted delivery of honokiol (HNK) to enhance drug delivery efficiency and specific biodistribution at tumor sites. The antisolvent precipitation and electrostatic interaction methods were employed to fabricate the PSA-Zein-HNK nanoparticles, which exhibited mean size of 107.2 ± 10.1 nm and HNK encapsulation efficiency of 79.2 ± 2.3%. The PSA-Zein-HNK maintained a uniform dispersion in serum for 48 h, implying the improved colloid stability of zein nanoparticles via PSA coating. The cellular uptake of PSA-Zein-Cou6 nanoparticles in 4 T1 cells was 2.58-fold higher than non-targeting Zein-Cou6. In addition, the IC₅₀ value at 48 h for PSA-Zein-HNK (4.37 μg/mL) was significantly higher than the Zein-HNK (7.74 μg/mL). Enhanced tumor accumulation of the PSA-Zein-HNK was confirmed in 4 T1 breast cancer-bearing mice by near-infrared fluorescence imaging, resulting in desirable antitumor efficacy and favorable biosafety. Besides, compared with non-targeting zein nanoparticles, the PSA-Zein-HNK achieved a higher tumor growth inhibition rate of 52.3%. In particular, the metastasis of breast cancer to the lung or liver was remarkably suppressed by PSA-Zein-HNK. Together, our results demonstrated that the PSA-Zein-HNK could be a potential tumor-targeted drug delivery strategy for efficient treatment of breast cancer.

Stromal Barrier-Dismantled Nanodrill-Like and Cancer Cell-Targeted pH-Responsive Polymeric Micelles for Further Enhancing the Anticancer Efficacy of Doxorubicin

Cancer-associated fibroblasts (CAFs) were believed to establish a tight physical barrier and a dense scaffold for tumor cells to make them maintain immunosuppression and drug resistance, strongly hindering nanoparticles to penetrate into the core of tumor tissues and limiting the performance of tumor cell-targeted nanoparticles. Here, we fabricated the substrate Z-Gly-Pro of fibroblast activation protein α (FAPα) and folic acid-codecorated pH-responsive polymeric micelles (dual ligand-modified PEOz-PLA polymeric micelles, DL-PP-PMs) that possessed nanodrill and tumor cell-targeted functions based on Z-Gly-pro-conjugated poly(2-ethyl-2-oxazoline)-poly(D,l-lactide) (ZGP-PEOz-PLA), folic acid (FA)-conjugated PEOz-PLA (FA-PEOz-PLA), and PEOz-PLA for cancer therapy. The micelles with about 40 nm particle size and a narrow distribution exhibited favorable pH-activated endo/lysosome escape induced by their pH responsibility. In addition, the enhancement of in vitro cellular uptake and cytotoxicity to folate receptors or FAPα-positive cells for doxorubicin (DOX)/DL-PP-PMs compared with DOX/PP-PMs evidenced the dual target ability of DOX/DL-PP-PMs, which was further supported by in vivo biodistribution results. As expected, in the human oral epidermal carcinoma (KB) cells xenograft nude mice model, the remarkable enhancement of antitumor efficacy for DOX/DL-PP-PMs with low toxicity was observed compared with DOX/FA-PP-PMs and DOX/ZGP-PP-PMs. The possible mechanism was elucidated to be the dismantling of the stromal barrier by nanodrill-like DOX/DL-PP-PMs via the deletion of CAFs evidenced by the downregulation of α-SMA and inhibition of their functions proved by the decrease in the microvascular density labeled with CD31 and the reduction in the extracellular matrix detected by the collagen content, thereby promoting tumor penetration and enhancing their uptake by tumor cells. The present research offered an alternative approach integrating anticancer and antifibrosis effects in one delivery system to enhance the delivery efficiency and therapeutic efficacy of anticancer drugs.

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

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

Lysine-mediated hydroxyethyl starch-10-hydroxy camptothecin micelles for the treatment of liver cancer

Liver cancer is a malignant tumor with extremely high morbidity and mortality. At present, traditional chemotherapy is still the most commonly used therapeutic approach. However, serious side effects lead to the treatment of liver cancer is not ideal. Therefore, it is imperative to develop a new drug delivery system based on nanotechnology and liver cancer microenvironment. In this study, a pH/reduction/α-amylase multi-sensitive hydroxyethyl starch-10-hydroxy camptothecin micelles (HES-10-HCPT-SS-Ly) targeting over-expressed amino acid (AA) transporters on the surface of liver cancer cell by applying lysine were successfully synthesized. The prepared micelles showed regular structure, suitable particle size, and intelligent drug release property. Compared with conventional HES-10-HCPT micelles and 10-HCPT injection, HES-10-HCPT-SS-Ly micelles demonstrated better in vitro anti-proliferative capability toward human liver cancer Hep-G2 cells and greater antitumor efficiency against nude mouse with Hep-G2 tumor. These findings suggest that HES-10-HCPT-SS-Ly micelles may be a promising nanomedicine for treatment of liver cancer.

Current Perspectives of the Applications of Polyphenols and Flavonoids in Cancer Therapy

The development of anticancer therapies that involve natural drugs has undergone exponential growth in recent years. Among the natural compounds that produce beneficial effects on human health, polyphenols have shown potential therapeutic applications in cancer due to their protective functions in plants, their use as food additives, and their excellent antioxidant properties. The possibility of combining conventional drugs-which are usually more aggressive than natural compounds-with polyphenols offers very valuable advantages such as the building of more efficient anticancer therapies with less side effects on human health. This review shows a wide range of trials in which polyphenolic compounds play a crucial role as anticancer medicines alone or in combination with other drugs at different stages of cancer: cancer initiation, promotion, and growth or progression. Moreover, the future directions in applications of various polyphenols in cancer therapy are emphasized.

Further Enhancement in Intestinal Absorption of Paclitaxel by Using Transferrin-Modified Paclitaxel Nanocrystals

The intestinal epithelium is considered to be a major obstacle to the gastrointestinal administration for water-insoluble drugs. To enhance the intestinal absorption of paclitaxel by improving its solubility and overcoming the intestinal epithelium barrier, transferrin-modified paclitaxel nanocrystals were prepared based on the specific transferrin receptor expressed on the apical membrane of the intestinal epithelium and examined to exhibit a mean size of around 178 nm, a rod-like morphology, a sustained release property, and an enhanced in vitro antitumor effect. The in situ intestinal perfusion study proved that the intestinal absorption of transferrin-modified paclitaxel nanocrystals was remarkably enhanced compared with that of Taxol and unmodified paclitaxel nanocrystals, which was further evidenced by the result of pharmacokinetic study. Their transcytosis pathway and intracellular trafficking track were disclosed using Caco-2 cell monolayers. The transcytosis of transferrin-modified paclitaxel nanocrystals and unmodified paclitaxel nanocrystals was principally mediated by clathrin and lipid rafts. The colocalization of both paclitaxel nanocrystals with the organelles observed under confocal microscopy suggested that the late endosomes, lysosomes, ER, and Golgi apparatus played a part in the transcellular transport of both paclitaxel nanocrystals during their transcytosis. Therefore, the designed transferrin-modified drug nanocrystals might have a great potential in the enhancement of intestinal absorption of water-insoluble drugs.

Targeted delivery of honokiol by zein/hyaluronic acid core-shell nanoparticles to suppress breast cancer growth and metastasis

Based on the antisolvent and electrostatic deposition methods, we fabricated zein/hyaluronic acid core-shell nanoparticles loaded with honokiol (HA-Zein-HNK), which could target delivery and enhance the therapeutic effect of the HNK. The prepared nanoparticles were found to have a mean size of 210.4 nm and negative surface charge. The HA-Zein-HNK nanoparticles exhibited improved antiproliferative and pro-apoptotic activities against 4T1 cells. Of note, the wound healing and transwell assessments indicated that the migration and invasion of 4T1 cells were markedly weakened by HA-Zein-HNK. Mechanistic insights revealed that HA-Zein-HNK downregulated the expressions of Vimentin and upregulated the expressions of E-cadherin. More importantly, an in vivo tissue distribution study demonstrated the excellent tumor target ability of HA-Zein. And these results correspond with the superior therapeutic efficacy of HA-Zein-HNK in 4T1 tumor bearing mice. In conclusion, we believe that HA-Zein nanoparticles may be served as a promising HNK delivery carrier for metastatic breast cancer therapy.

Hyaluronic acid-modified liposomal honokiol nanocarrier: Enhance anti-metastasis and antitumor efficacy against breast cancer

In an effort to enhance antitumor and anti-metastasis of breast cancer, honokiol (HNK) was encapsulated into hyaluronic acid (HA) modified cationic liposomes (Lip). The prepared HA-Lip-HNK had a spherical shape with a narrow size distribution. The enhanced antitumor efficacy of HA-Lip-HNK was investigated in 4T1 cells in vitro, wherein flow cytometry and confocal microscopy analysis revealed its HA/CD44-mediated greater cellular internalization. As anticipate, the significant cytotoxicity of the HA-Lip-HNK was also observed in 4T1 tumor spheroids. Furthermore, the superior prevention of tumor metastasis by HA-Lip-HNK was verified by in vitro anti-invasion, wound healing and anti-migration assessments, and in vivo bioluminescence imaging in pulmonary metastasis model. Finally, compared with unmodified liposomes, the HA-Lip-HNK exhibited higher tumor accumulation, and achieved a tumor growth inhibition rate of 59.5 %. As a result, the HA-Lip-HNK may serve as a promising tumor-targeted drug delivery strategy for the efficient therapy of metastatic breast cancer.

Multi pH-sensitive polymer–drug conjugate mixed micelles for efficient co-delivery of doxorubicin and curcumin to synergistically suppress tumor metastasis

Multi pH-responsive polymer-drug conjugate mixed micelles were fabricated to co-deliver doxorubicin and curcumin for synergistic suppression tumor metastasis via inhibiting the invasion, migration, intravasation and extravasation of tumor cells.

Intestinal oligopeptide transporter PepT1-targeted polymeric micelles for further enhancing the oral absorption of water-insoluble agents

The intestinal epithelium is the main barrier for nanocarriers to orally deliver poorly water-soluble and absorbed agents. To further improve the transmembrane transport efficiency of polymeric micelles, intestinal oligopeptide transporter PepT1-targeted polymeric micelles were fabricated by Gly-Sar-conjugated poly(ethylene glycol)-poly(d,l-lactic acid). The functionalized polymeric micelles with about 40 nm diameter, uniform spherical morphology and favorable cytocompatibility with Caco-2 cells were demonstrated to distinctly enhance the cellular uptake and transmembrane transport of the loaded agents. The results of intestinal absorption strongly evidenced the higher accumulation of the micelles inside the epithelial cells, at the apical and basolateral sides of the epithelium within the villi in mice. Furthermore, the interaction of Gly-Sar decorated polymeric micelles with PepT1 was explored to promote the internalization of the micelles through fluorescence immunoassay, and the PepT1 level on the membrane of Caco-2 cells treated with the micelles appeared to change in a distinctly time-dependent manner. Both clathrin- and caveolae-mediated pathways were involved in the transcellular transport for undecorated polymeric micelles, while the transcellular transport pathway for Gly-Sar decorated ones was changed to be mainly mediated by clathrin and lipid rafts. The colocalization of Gly-Sar decorated micelles with the organelles observed by confocal laser scanning microscopy indicated that late endosomes, lysosomes, endoplasmic reticulum and Golgi apparatus appeared to participate in the intracellular trafficking progression of the micelles. These results suggested that PepT1-targeted polymeric micelles might have a strong potential to greatly promote the oral absorption of poorly water-soluble and absorbed agents.

The E-Cadherin and N-Cadherin Switch in Epithelial-to-Mesenchymal Transition: Signaling, Therapeutic Implications, and Challenges

Epithelial-to-Mesenchymal Transition (EMT) has been shown to be crucial in tumorigenesis where the EMT program enhances metastasis, chemoresistance and tumor stemness. Due to its emerging role as a pivotal driver of tumorigenesis, targeting EMT is of great therapeutic interest in counteracting metastasis and chemoresistance in cancer patients. The hallmark of EMT is the upregulation of N-cadherin followed by the downregulation of E-cadherin, and this process is regulated by a complex network of signaling pathways and transcription factors. In this review, we summarized the recent understanding of the roles of E- and N-cadherins in cancer invasion and metastasis as well as the crosstalk with other signaling pathways involved in EMT. We also highlighted a few natural compounds with potential anti-EMT property and outlined the future directions in the development of novel intervention in human cancer treatments. We have reviewed 287 published papers related to this topic and identified some of the challenges faced in translating the discovery work from bench to bedside.

Chemiluminescence and Bioluminescence Imaging for Biosensing and Therapy: In Vitro and In Vivo Perspectives

Chemiluminescence (CL) and bioluminescence (BL) imaging technologies, which require no external light source so as to avoid the photobleaching, background interference and autoluminescence, have become powerful tools in biochemical analysis and biomedical science with the development of advanced imaging equipment. CL imaging technology has been widely applied to high-throughput detection of a variety of analytes because of its high sensitivity, high efficiency and high signal-to-noise ratio (SNR). Using luciferase and fluorescent proteins as reporters, various BL imaging systems have been developed innovatively for real-time monitoring of diverse molecules in vivo based on the reaction between luciferin and the substrate. Meanwhile, the kinetics of protein interactions even in deep tissues has been studied by BL imaging. In this review, we summarize in vitro and in vivo applications of CL and BL imaging for biosensing and therapy. We first focus on in vitro CL imaging from the view of improving the sensitivity. Then, in vivo CL applications in cells and tissues based on different CL systems are demonstrated. Subsequently, the recent in vitro and in vivo applications of BL imaging are summarized. Finally, we provide the insight into the development trends and future perspectives of CL and BL imaging technologies.

Redox Stimuli Delivery Vehicle Based on Transferrin-Capped MSNPs for Targeted Drug Delivery in Cancer Therapy

Cancer has become one of the major diseases of human health around the world. Conventional antitumor drugs cannot specifically target cancers and result in serious side effects. To achieve better therapy, innovative functional drug delivery platforms that will aid specific targeting for cancer cells need to be developed. In this study, transferrin (Tf), which can target cancer cells, is covalently anchored onto the surface of MSNPs via disulfide linkage, which is used for glutathione-triggered intracellular drug release in tumor cells. The successful functionalization of redox-responsive MSNPs is confirmed by using BET/BJH, TEM, TGA, NMR, and FT-IR (BET, Brunauer-Emmett-Teller; BJH, Barrett-Joyner-Halenda). In addition, polyethylene glycol (PEG) is further grafted onto the surface of MSNPs to improve the biocompatibility and stability under physiological conditions for longer blood circulation. Our in vitro studies demonstrate that DOX-loaded MSNP-SS-Tf@PEG can selectively be internalized into cancer cells via Tf/Tf receptor interactions, and then, DOX is released in HT-29 and MCF-7 cells triggered by high GSH concentration in tumor cells. Remarkably, in vivo studies demonstrate that DOX-loaded MSNP-SS-Tf@PEG can significantly inhibit tumor growth with minimized side effects through cell apoptosis determined by TUNEL assay, whereas MSNP-SS-Tf@PEG revealed no significant inhibition. In conclusion, DOX-MSNP-SS-Tf@PEG with active targeting moieties and a redox-responsive strategy has been demonstrated as a great effective drug carrier for tumor therapy in vitro and in vivo.

Stepwise dual pH and redox-responsive cross-linked polypeptide nanoparticles for enhanced cellular uptake and effective cancer therapy

The systemic toxicity, reduced cellular internalization, and uncontrollable intracellular drug release of smart nanoparticles (NPs) still need to be overcome for effective cancer therapy.