Paclitaxel and Tacrolimus Coencapsulated Polymeric Micelles That Enhance the Therapeutic Effect of Drug-Resistant Ovarian Cancer

Tacrolimus and paclitaxel co-loaded O/O ointment without surfactant: Synergistic combinations for the treatment of psoriasis

Psoriasis is an autoimmune disorder disease with abnormally activated T lymphocytes and thickening of the epidermis. The mechanism of the action of tacrolimus and paclitaxel are matched with the two only known pathogenesis of psoriasis. However, there has been no report on tacrolimus combined with paclitaxel in the treatment of psoriasis until now. The O/O ointment was prepared for the topical application to overcome poor solubility, poor skin penetration, and erratic absorption of the two drugs. A high-speed shearing method was adopted to prepare the ointment, in which propylene carbonate was used to solve tacrolimus and paclitaxel completely. The ointment showed excellent stability, slow release of the drugs, better retention in psoriatic skin, and good skin tolerance. The therapeutic efficacy of ointment was evaluated with imiquimod induced psoriatic model, and the level of expression of psoriatic biochemical markers was evaluated using the PASI score and immunohistochemistry. The cumulative PASI score was 10.8 for the imiquimod induced group, 7.8 for the tacrolimus ointment group, 8.3 for the paclitaxel ointment and 5.3 for the tacrolimus-paclitaxel (1:1) ointment group, respectively. Ointment group with tacrolimus and paclitaxel indicated a significant improvement in the phenotypic features of the psoriatic skin treated. Compared with the imiquimod group, tacrolimus-paclitaxel (1:1) ointment group was significantly reduced the level of IL-17. The results confirm that tacrolimus and paclitaxel co-loaded ointment can be an effective strategy for the treatment of psoriasis.

Current Update on Nanotechnology-Based Approaches in Ovarian Cancer Therapy

Ovarian cancer is one of the leading causes of cancer-related deaths among women. The drawbacks of conventional therapeutic strategies encourage researchers to look for alternative strategies, including nanotechnology. Nanotechnology is one of the upcoming domains of science that is rechanneled towards targeted cancer therapy and diagnosis. Nanocarriers such as dendrimers, liposomes, polymer micelles, and polymer nanoparticles present distinct surface characteristics in morphology, surface chemistry, and mode of action that help differentiate normal and malignant cells, which paves the way for target-specific drug delivery. Similarly, nanoparticles have been strategically utilized as efficacious vehicles to deliver drugs that alter the epigenetic modifications in epigenetic therapy. Some studies suggest that the use of specialized target-modified nanoparticles in siRNA-based nanotherapy prevents internalization and improves the antitumor activity of siRNA by ensuring unrestrained entry of siRNA into the tumor vasculature and efficient intracellular delivery of siRNA. Moreover, research findings highlight the significance of utilizing nanoparticles as depots for photosensitive drugs in photodynamic therapy. The applicability of nanoparticles is further extended to medical imaging. They serve as contrast agents in combination with conventional imaging modalities such as MRI, CT, and fluorescence-based imaging to produce vivid and enhanced images of tumors. Therefore, this review aims to explore and delve deeper into the advent of various nanotechnology-based therapeutic and imaging techniques that provide non-invasive and effective means to tackle ovarian cancers.

Emerging nanotechnology based combination therapies of taxanes for multiple drug-resistant cancers

'One drug- one target' to 'multiple drug- multiple targets' paradigm shifted to produce combination therapies, have found great outcomes to overcome multiple drug resistance (MDR). MDR is a significant barrier to the delivery of taxane-based anticancer medicines such as docetaxel, paclitaxel, and cabazitaxel. Due to MDR induced by drug efflux transporters, clinical application of these medications is impeded. To date, nanoformulations such as liposomes, micelles, polymeric nanoparticles, and gold nanoparticles have been investigated to deliver taxanes alone and in combination to reverse drug resistance. Despite the fact that various groups have already looked into taxane nano formulations in the literature, there isn't much in the way of polypharmacology and advanced nanoformulations with a focus on MDR. In this overview, we briefly covered the insights regarding MDR, difficulties related to current pharmaceutical products of taxanes, combination therapies of taxanes to combat MDR, all of which can be used to delve into cancer treatment.

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.

Towards next-generation personalization of tacrolimus treatment: a review on advanced diagnostic and therapeutic approaches

The benefit of personalized medicine is that it allows the customization of drug therapy - maximizing efficacy while avoiding side effects. Genetic polymorphisms are one of the major contributors to interindividual variability. Currently, the only gold standard for applying personalized medicine is dose titration. Because of technological advancements, converting genotypic data into an optimum dose has become easier than in earlier years. However, for many medications, determining a personalized dose may be difficult, leading to a trial-and-error method. On the other hand, the technologically oriented pharmaceutical industry has a plethora of smart drug delivery methods that are underutilized in customized medicine. This article elaborates the genetic polymorphisms of tacrolimus as case study, and extensively covers the diagnostic and therapeutic technologies which aid in the delivery of personalized tacrolimus treatment for better clinical outcomes, thereby providing a new strategy for implementing personalized medicine.

Adjudin-loaded redox-sensitive paclitaxel-prodrug micelles for overcoming multidrug resistance with efficient targeted Colon cancer therapy

Multidrug resistance (MDR) is the primary cause for the failure of chemotherapy in the treatment of colon cancer. Recent research has indicated that the combination of a chemotherapeutic agent and a mitochondrial inhibitor might represent a promising strategy to help overcome MDR. However, for this approach to be clinically effective, it is important that the two drugs can be actively and simultaneously delivered into tumor cells at an optimal ratio and completely released drug within cells. To address these challenges, we designed and prepared a folate receptor-targeted and redox-responsive drug delivery system (FA-ss-P/A) that was able to co-deliver paclitaxel (PTX) and adjudin (ADD) to reverse colon cancer MDR. The PTX prodrug was obtained by conjugating PTX to dextrin via a disulfide-linkage. Then, folic acid (FA) was modified on the PTX prodrug. Finally, ADD, a mitochondrial inhibitor, was encapsulated in the PTX prodrug-formed micelles. A series of in vitro and in vivo experiments subsequently demonstrated that FA-ss-P/A can effectively reverse MDR by increasing cell uptake, inhibiting PTX efflux, and improving drug release.

Recent advances in co-delivery nanosystems for synergistic action in cancer treatment

Nanocarrier delivery systems have been widely studied to carry unique or dual chemical drugs. The major challenge of chemotherapies is to overcome the multidrug-resistance (MDR) of cells to antineoplastic medicines. In this context, nano-scale technology has allowed researchers to develop biocompatible nano-delivery systems to overcome the limitation of chemical agents. The development of nano-vehicles may also be directed to co-deliver different agents such as drugs and genetic materials. The delivery of nucleic acids targeting specific cells is based on gene therapy principles to replace the defective gene, correct genome errors or knock-down a particular gene. Co-delivery systems are attractive strategies due to the possibility of achieving synergistic therapeutic effects, which are more effective in overcoming the MDR of cancer cells. These combined therapies can provide better outcomes than separate delivery approaches carrying either siRNA, miRNA, pDNA, or drugs. This article reviews the main design features that need to be associated with nano-vehicles to co-deliver drugs, genes, and gene-drug combinations with efficacy. The advantages and disadvantages of co-administration approaches are also overviewed and compared with individual nanocarrier systems. Herein, future trends and perspectives in designing novel nano-scale platforms to co-deliver therapeutic agents are also discussed.

Synergistic Combination of Bioactive Hydroxyapatite Nanoparticles and the Chemotherapeutic Doxorubicin to Overcome Tumor Multidrug Resistance

Multidrug resistance (MDR) is one of the biggest obstacles in cancer chemotherapy. Here, a remarkable reversal of MDR in breast cancer through the synergistic effects of bioactive hydroxyapatite nanoparticles (HAPNs) and doxorubicin (DOX) is shown. DOX loaded HAPNs (DHAPNs) exhibit a 150-fold reduction in IC₅₀ compared with free DOX for human MDR breast cancer MCF-7/ADR cells, and lead to almost complete inhibition of tumor growth in vivo without obvious side effects of free DOX. This high efficacy and specificity could be attributed to multiple action mechanisms of HAPNs. In addition to acting as the conventional nanocarriers to facilitate the cellular uptake and retention of DOX in MCF-7/ADR cells, more importantly, drug-free HAPNs themselves are able to prevent drug being pumped out of MDR cells through targeting mitochondria to induce mitochondrial damage and inhibit ATP production and to trigger sustained mitochondrial calcium overload and apoptosis in MDR cancer cells while not affecting normal cells. The results demonstrate that this simple but versatile bioactive nanoparticle provides a practical approach to effectively overcome MDR.

Polymeric Nanoparticle Delivery of Combination Therapy with Synergistic Effects in Ovarian Cancer

Treatment of ovarian cancer is challenging due to late stage diagnosis, acquired drug resistance mechanisms, and systemic toxicity of chemotherapeutic agents. Combination chemotherapy has the potential to enhance treatment efficacy by activation of multiple downstream pathways to overcome drug resistance and reducing required dosages. Sequence of delivery and the dosing schedule can further enhance treatment efficacy. Formulation of drug combinations into nanoparticles can further enhance treatment efficacy. Due to their versatility, polymer-based nanoparticles are an especially promising tool for clinical translation of combination therapies with tunable dosing schedules. We review polymer nanoparticle (e.g., micelles, dendrimers, and lipid nanoparticles) carriers of drug combinations formulated to treat ovarian cancer. In particular, the focus on this review is combinations of platinum and taxane agents (commonly used first line treatments for ovarian cancer) combined with other small molecule therapeutic agents. In vitro and in vivo drug potency are discussed with a focus on quantifiable synergistic effects. The effect of drug sequence and dosing schedule is examined. Computational approaches as a tool to predict synergistic drug combinations and dosing schedules as a tool for future nanoparticle design are also briefly discussed.

Heat Shock Protein 90 Triggers Multi-Drug Resistance of Ovarian Cancer via AKT/GSK3β/β-Catenin Signaling

Ovarian cancer is the most lethal gynaecologic tumor, with which multi-drug resistance as the major therapeutic hindrance. Heat shock protein 90 (Hsp90) has been involved in cancer malignant behaviors. However, its role and mechanism in multi-drug resistance of ovarian cancer remains poorly understood. Our results demonstrated that Hsp90 was overexpressed in multi-drug resistant ovarian cancer cells. Hsp90 downregulation by shHsp90 or inhibitor BIIB021 increased the sensitivity of multi-drug resistant ovarian cancer cells to paclitaxel and cisplatin, and augmented the drugs-induced apoptosis. Hsp90 positively regulated the expressions of multi-drug resistance protein 1 (P-gp/MDR1), breast cancer resistance protein (BCRP), Survivin and Bcl-2 expressions closely associated with multi-drug resistance. Moreover, overexpression of Hsp90 promoted β-catenin accumulation, while Hsp90 downregulation decreased the accumulation, nuclear translocation and transcriptional activity of β-catenin. We also identified that β-catenin was responsible for Hsp90-mediated expressions of P-gp, BCRP, Survivin, and Bcl-2. Furthermore, Hsp90 enhanced the AKT/GSK3β signaling, and AKT signaling played a critical role in Hsp90-induced accumulation and transcriptional activity of β-catenin, as well as multi-drug resistance to paclitaxel and cisplatin. In conclusion, Hsp90 enhanced the AKT/GSK3β/β-catenin signaling to induce multi-drug resistance of ovarian cancer. Suppressing Hsp90 chemosensitized multi-drug resistant ovarian cancer cells via impairing the AKT/GSK3β/β-catenin signaling, providing a promising therapeutic strategy for a successful treatment of ovarian cancer.

A novel self-assembled micelles based on stearic acid modified schizophyllan for efficient delivery of paclitaxel

This study was aimed to design a novel amphiphilic carrier based on schizophyllan (SPG) exopolysacharide for drug delivery. Stearic acid (SA) was used for the esterification of SPG with two degrees of substitutions (SA-SPG0.5 and SA-SPG1). The H NMR and FTIR spectroscopies verified the succesfull esterification of SPG. The polymeric micelles easily self-assembled into nanomicelles by ultrasound method. Fluorescence spectroscopy showed that the critical micelle concentrations (CMCs) of SA-SPG0.5 and SA-SPG1 micelles were 0.068 mg/mL and 0.027 mg/mL, respectively. DLS analyses showed that nanomicelles were ranged from 156 to 175 nm. SEM and TEM images showed that nanomicelles were mostly spherical. Paclitaxel (PTX) as a drug model was successfully loaded into SA-SPG nanomicelles with three different drug/polymer weight ratios of 0.1, 0.2 and 0.3. The highest encapsulation efficiency (75 %) was obtained when the PTX/SA-SPG weight ratio was 0.1. The in vitro release of PTX from SA-SPG micelles represented the sustained release profile over 144 h. MTT assay showed that the PTX-loaded SA-SPG nanomicelles had the higher cytotoxicity against MCF-7 cells than free PTX. These results revealed that the synthesized SA-SPG nanomicelles had a promising potential as a new carrier for efficient delivery of hydrophobic drugs.

Nanoparticle delivery systems to combat drug resistance in ovarian cancer

Due to the lack of early symptoms and difficulty of accurate diagnosis, ovarian cancer is the most lethal gynecological cancer faced by women. First-line therapy includes a combination of tumor resection surgery and chemotherapy regimen. However, treatment becomes more complex upon recurrence due to development of drug resistance. Drug resistance has been linked to many mechanisms, including efflux transporters, apoptosis dysregulation, autophagy, cancer stem cells, epigenetics, and the epithelial-mesenchymal transition. Thus, developing and choosing effective therapies is exceptionally complex. There is a need for increased specificity and efficacy in therapies for drug-resistant ovarian cancer, and research in targeted nanoparticle delivery systems aims to fulfill this challenge. Although recent research has focused on targeted nanoparticle-based therapies, few of these therapies have been clinically translated. In this review, non-viral nanoparticle delivery systems developed to overcome drug-resistance in ovarian cancer were analyzed, including their structural components, surface modifications, and drug-resistance targeted mechanisms.

Atherosclerosis and Nanomedicine Potential: Current Advances and Future Opportunities

Atherosclerosis is the leading inducement of cardiovascular diseases, which ranks the first cause of global deaths. It is an arterial disease associated with dyslipidemia and changes in the composition of the vascular wall. Besides invasive surgical strategy, the current conservative clinical treatment for atherosclerosis falls into two categories, lipid regulating-based therapy and antiinflammatory therapy. However, the existing strategies based on conventional drug delivery systems have shown limited efficacy against disease development and plenty of side effects. Nanomedicine has great potential in the development of targeted therapy, controlled drug delivery and release, the design of novel specific drugs and diagnostic modalities, and biocompatible scaffolds with multifunctional characteristics, which has led to an evolution in the diagnosis and treatment of atherosclerosis. This paper will focus on the latest nanomedicine strategies for atherosclerosis diagnosis and treatment as well as discussing the potential therapeutic targets during atherosclerosis progress, which could form the basis of development of novel nanoplatform against atherosclerosis.

Novel "Carrier-Free" Nanofiber Codelivery Systems with the Synergistic Antitumor Effect of Paclitaxel and Tetrandrine through the Enhancement of Mitochondrial Apoptosis

Paclitaxel (Ptx), a type of microtubule depolymerization inhibitor, is one of the main components in gastric cancer chemotherapy. Some studies have demonstrated that tetrandrine (Tet), a bisbenzylisoquinoline alkaloid, has potential antitumor effects in several cancers. Aside from the direct anticancer effect, Tet is proved to synergistically enhance the antitumor effect of Ptx in gastric cancer. However, the application of the combinational strategy is limited by the poor solubility of both drugs. Nanodrug delivery systems including polymeric nanoparticles, self-assembled nanofibers, hydrogels, etc., hold the potential to meet the need. Here, a novel supramolecular nanomaterial, based on the concept of "carrier-free nanodrugs", is reported as a feasible platform for synergistic drug delivery. Ptx-SA-RGD is obtained through the conjugation of Ptx and the tumor-specific peptide RGD (arginine-glycine-aspartic acid) with succinic acid (SA) as a linker. Ptx-SA-RGD could self-assemble into Ptx nanofibers (P-NFs) with high drug-loading efficiency. Tet was then encapsulated into P-NFs to acquire novel Ptx and Tet coloaded self-assembled nanofibers (P/T-NFs). The uptake study shows the dynamic internalization of P/T-NFs by the gastric cancer cell line MGC-803. P/T-NFs significantly triggered the accumulation of reactive oxygen species (ROS) in gastric cancer cells MGC803 and further decreased the mitochondrial membrane potential, which led to the induction of mitochondrial apoptosis with superior cytotoxicity against free drugs. Moreover, P/T-NFs suppressed the expressions of p-STAT3 and p-JAK, initiated cytochrome-C release, and promoted caspase protein expression. Furthermore, P/T-NFs demonstrated the strongest tumor-delaying effect as well as the lowest toxicity. Therefore, self-assembled nanofibers of P/T-NFs demonstrated an increase of the mitochondrial apoptosis level and a stronger antitumor effect both in vitro and in vivo, which could be a potential way to enhance the clinical efficacy and reduce the side-effects of Ptx in gastric cancer.

Doxorubicin derivative loaded acetal-PEG-PCCL micelles for overcoming multidrug resistance in MCF-7/ADR cells

Objective: This study was aimed to develop DOX-TPP loaded acetal-PEG-PCCL micelles to improve the clinical efficacy of drug resistance tumor. Significance: Chemotherapy is one of the main treatments for breast cancer but is plagued by multidrug resistance (MDR). DOX-TPP-loaded micelles can enhance the specific concentration of drugs in the tumor and improve the efficacy and overcome MDR. Methods: In this study, DOX-TPP-loaded micelles based on acetal-PEG-PCCL were prepared and their physicochemical properties were characterized. The cellular uptake and ability to induce apoptosis of the micelles was confirmed by flow cytometry in MCF-7/ADR cells. In addition, cytotoxicity of the micelles was studied in MCF-7 cells and MCF-7/ADR cells. Confocal is used to study the subcellular distribution of DOX. Free DOX-TPP or DOX-TPP-loaded acetal-PEG-PCCL micelles were administered via intravenous injection in the tail vain for the biodistribution study in vivo. Results: The diameter of micelles was about 102.4 nm and their drug-loading efficiency is 61.8%. The structural characterization was confirmed by 1H NMR. The micelles exhibited better antitumor efficacy compared to free doxorubicin in MCF-7/ADR cells by MTT assay. The apoptotic rate and the cellular uptake of micelles were significantly higher than free DOX and DOX-TPP. Micelles can efficiently deliver mitochondria-targeting DOX-TPP to tumor cells. The result of bio-distribution showed that the micelles had stronger tumor infiltration ability than free drugs. Conclusions: In this study, mitochondriotropic DOX-TPP was conjugated to the nanocarrier acetal-PEG-PCCL via ionic interaction to form a polymer, which spontaneously formed spherical micelles. The cytotoxicity and cellular uptake of the micelles are superior to free DOX and exhibit mitochondrial targeting and passive tumor targeting, indicating that they have potential prospects.

Dendritic cell engineering for selective targeting of female reproductive tract cancers

Female reproductive tract cancers (FRCs) are considered as one of the most frequently occurring malignancies and a foremost cause of death among women. The late-stage diagnosis and limited clinical effectiveness of currently available mainstay therapies, primarily due to the developed drug resistance properties of tumour cells, further increase disease severity. In the past decade, dendritic cell (DC)-based immunotherapy has shown remarkable success and appeared as a feasible therapeutic alternative to treat several malignancies, including FRCs. Importantly, the clinical efficacy of this therapy is shown to be restricted by the established immunosuppressive tumour microenvironment. However, combining nanoengineered approaches can significantly assist DCs to overcome this tumour-induced immune tolerance. The prolonged release of nanoencapsulated tumour antigens helps improve the ability of DC-based therapeutics to selectively target and remove residual tumour cells. Incorporation of surface ligands and co-adjuvants may further aid DC targeting (in vivo) to overcome the issues associated with the short DC lifespan, immunosuppression and imprecise uptake. We herein briefly discuss the necessity and progress of DC-based therapeutics in FRCs. The review also sheds lights on the future challenges to design and develop clinically effective nanoparticles-DC combinations that can induce efficient anti-tumour immune responses and prolong patients’ survival.

Natural product-based nanoformulations for cancer therapy: Opportunities and challenges

Application of natural product-based nanoformulations for the treatment of different human diseases, such as cancer, is an emerging field. The conventional cancer therapeutic modalities, including surgery, chemotherapy, immunotherapy, radiotherapy has limited achievements. A larger number of drawbacks are associated with these therapies, including damage to proliferating healthy tissues, structural deformities, systemic toxicity, long-term side effects, resistance to the drug by tumor cells, and psychological problems. The advent of nanotechnology in cancer therapeutics is recent; however, it has progressed and transformed the field of cancer treatment at a rapid rate. Nanotherapeutics have promisingly overcome the limitations of conventional drug delivery system, i.e., low aqueous solubility, low bioavailability, multidrug resistance, and non-specificity. Specifically, natural product-based nanoformulations are being intentionally studied in different model systems. Where it is found that these nanoformulations has more proximity and reduced side effects. The nanoparticles can specifically target tumor cells, enhancing the specificity and efficacy of cancer therapeutic modalities which in turn improves patient response and survival. The integration of phytotherapy and nanotechnology in the clinical setting may improve pharmacological response and better clinical outcome of patients.

Rising horizon in circumventing multidrug resistance in chemotherapy with nanotechnology

Multidrug resistance (MDR) is one of the key barriers in chemotherapy, leading to the generation of insensitive cancer cells towards administered therapy. Genetic and epigenetic alterations of the cells are the consequences of MDR, resulted in drug resistivity, which reflects in impaired delivery of cytotoxic agents to the cancer site. Nanotechnology-based nanocarriers have shown immense shreds of evidence in overcoming these problems, where these promising tools handle desired dosage load of hydrophobic chemotherapeutics to facilitate designing of safe, controlled and effective delivery to specifically at tumor microenvironment. Therefore, encapsulating drugs within the nano-architecture have shown to enhance solubility, bioavailability, drug targeting, where co-administered P-gp inhibitors have additionally combat against developed MDR. Moreover, recent advancement in the stimuli-sensitive delivery of nanocarriers facilitates a tumor-targeted release of the chemotherapeutics to reduce the associated toxicities of chemotherapeutic agents in normal cells. The present article is focused on MDR development strategies in the cancer cell and different nanocarrier-based approaches in circumventing this hurdle to establish an effective therapy against deadliest cancer disease.

A nanomedicine approach enables co-delivery of cyclosporin A and gefitinib to potentiate the therapeutic efficacy in drug-resistant lung cancer

Drug resistance, accounting for therapeutic failure in the clinic, remains a major challenge to effectively manage cancer. Cyclosporin A (CsA) can reverse multidrug resistance (MDR), especially resistance to epidermal growth factor receptor tyrosine kinase inhibitors. However, the application of both drugs in cancer therapies is hampered by their poor aqueous solubility and low bioavailability due to oral administration. CsA augments the potency of gefitinib (Gef) in both Gef-sensitive and Gef-resistant cell lines. Here, we show that the simultaneous encapsulation of CsA and Gef within polyethylene glycol-block-poly(_{D, L}-lactic acid) (PEG-PLA) produced a stable and systemically injectable nanomedicine, which exhibited a sub-50-nm diameter and spherical structures. Impressively, the co-delivery of therapeutics via single nanoparticles (NPs) outperformed the oral administration of the free drug combination at suppressing tumor growth. Furthermore, in vivo results indicated that CsA formulated in NPs sensitized Gef-resistant cells and Gef-resistant tumors to Gef treatment by inactivating the STAT3/Bcl-2 signaling pathway. Collectively, our nanomedicine approach not only provides an alternative administration route for the drugs of choice but also effectively reverses MDR, facilitating the development of effective therapeutic modalities for cancer.

Injection of nanoparticles containing the anticancer drug gefitinib and the immunosuppressant cyclosporin A reverses drug-resistant cancer growth in mice. The development of multidrug resistance is the main reason why many forms of chemotherapy fail. Cyclosporin A, a drug used to prevent immune rejection after organ transplantation, has previously been shown to enhance the potency of gefitinib. Hangxiang Wang and colleagues at Zhejiang University, Hangzhou, China, have successfully combined cyclosporin A and gefitinib, two poorly water-soluble and slowly absorbed drugs, into stable injectable nanoparticles that delay the growth of gefitinib resistant human lung cancer cells as well as the growth of drug resistant tumors in mice. Importantly, this novel co-formulation was more effective than oral co-administration of the two drugs. Further investigation into this drug delivery route could yield much needed alternative treatments for patients with multidrug-resistant cancers.

pH-triggered surface charge-switchable polymer micelles for the co-delivery of paclitaxel/disulfiram and overcoming multidrug resistance in cancer

Multidrug resistance (MDR) remains a major challenge for providing effective chemotherapy for many cancer patients. To address this issue, we report an intelligent polymer-based drug co-delivery system which could enhance and accelerate cellular uptake and reverse MDR. The nanodrug delivery systems were constructed by encapsulating disulfiram (DSF), a P-glyco-protein (P-gp) inhibitor, into the hydrophobic core of poly(ethylene glycol)-block-poly(l-lysine) (PEG-b-PLL) block copolymer micelles, as well as 2,3-dimethylmaleic anhydride (DMA) and paclitaxel (PTX) were grafted on the side chain of l-lysine simultaneously. The surface charge of the drug-loaded micelles represents as negative in plasma (pH 7.4), which is helpful to prolong the circulation time, and in a weak acid environment of tumor tissue (pH 6.5-6.8) it can be reversed to positive, which is in favor of their entering into the cancer cells. In addition, the carrier could release DSF and PTX successively inside cells. The results of in vitro studies show that, compared to the control group, the DSF and PTX co-loaded micelles with charge reversal exhibits more effective cellular uptake and significantly increased cytotoxicity of PTX to MCF-7/ADR cells which may be due to the inhibitory effect of DSF on the efflux function of P-gp. Accordingly, such a smart pH-sensitive nanosystem, in our opinion, possesses significant potential to achieve combinational drug delivery and overcome drug resistance in cancer therapy.

A simple reduction-sensitive micelles co-delivery of paclitaxel and dasatinib to overcome tumor multidrug resistance

Multidrug resistance (MDR) is one of the major obstacles in successful chemotherapy. The combination of chemotherapy drugs and multidrug-resistant reversing agents for treating MDR tumor is a good strategy to overcome MDR. In this work, we prepared the simple redox-responsive micelles based on mPEG-SS-C18 as a co-delivery system to load the paclitaxel (PTX) and dasatinib (DAS) for treatment of MCF-7/ADR cells. The co-loaded micelles had a good dispersity and a spherical shape with a uniform size distribution, and they could quickly disassemble and rapidly release drugs under the reduction environment. Compared with MCF-7 cells, the DAS and PTX co-loaded redox-sensitive micelle (SS-PDNPs) showed stronger cytotoxicity and a more improving intracellular drug concentration than other drug formulations in MCF-7/ADR cells. In summary, the results suggested that the simple co-delivery micelles of PTX and DAS possessed significant potential to overcome drug resistance in cancer therapy.

PTD modified paclitaxel anti-resistant liposomes for treatment of drug-resistant non-small cell lung cancer

CONTEXT

Non-small cell lung carcinoma (NSCLC) is a type of epithelial lung cancer that accounts for approximately 80-85% of lung carcinoma cases. Chemotherapy for the NSCLC is unsatisfactory due to multidrug resistance, nonselectively distributions and the accompanying side effects.

OBJECTIVE

The objective of this study was to develop a kind of PTD modified paclitaxel anti-resistant liposomes to overcome these chemotherapy limitations.

METHOD

The studies were performed on LLT cells and resistant LLT cells in vitro and on NSCLC xenograft mice in vivo, respectively.

RESULTS AND DISCUSSION

In vitro results showed that the liposomes with suitable physicochemical characteristics could significantly increase intracellular uptake in both LLT cells and resistant LLT cells, evidently inhibit the growth of cancer cells, and clearly induce the apoptosis of resistant LLT cells. Studies on resistant LLT cells xenograft mice demonstrated that the liposomes magnificently enhanced the anticancer efficacy in vivo. Involved action mechanisms were down-regulation of adenosine triphosphate binding cassette transporters on resistant LLT cells, and activation of the apoptotic enzymes (caspase 8/9/3).

CONCLUSION

The PTD modified paclitaxel anti-resistant liposomes may provide a promising strategy for treatment of the drug-resistant non-small cell lung cancer.

Self-assembly of glutamic acid linked paclitaxel dimers into nanoparticles for chemotherapy

In this work, a glutamic acid linked paclitaxel (PTX) dimer (Glu-PTX₂) with high PTX content of 88.9wt% was designed and synthesized. Glu-PTX₂ could self-assemble into nanoparticles (Glu-PTX₂ NPs) in aqueous solution to increase the water solubility of PTX. Glu-PTX₂ NPs were characterized by electron microscopy and dynamic light scattering, exhibiting spherical morphology and favorable structural stability in aqueous media. Glu-PTX₂ NPs could be internalized by cancer cells as revealed by confocal laser scanning microscopy and exert potent cytotoxicity. It is envisaged that Glu-PTX₂ NPs would be an alternative formulation for PTX, and such amino acid linked drug dimers could also be applied to other therapeutic agents.

Biodegradable polymeric micelles coencapsulating paclitaxel and honokiol: a strategy for breast cancer therapy in vitro and in vivo

The combination of chemotherapy drugs attracts more attention in clinical cancer trials. However, the poor water solubility of chemotherapeutic drugs restricts their anticancer application. In order to improve antitumor efficiency and reduce side effects of free drugs, we prepared paclitaxel (PTX) and honokiol (HK) combination methoxy poly(ethylene glycol)–poly(caprolactone) micelles (P–H/M) by solid dispersion method against breast cancer. The particle size of P–H/M was 28.7±2.5 nm, and transmission electron microscope image confirmed that P–H/M were spherical in shape with small particle size. After being encapsulated in micelles, the release of PTX or HK showed a sustained behavior in vitro. In addition, both the cytotoxicity and the cellular uptake of P–H/M were increased in 4T1 cells, and P–H/M induced more apoptosis than PTX-loaded micelles or HK-loaded micelles, as analyzed by flow cytometry assay and Western blot. Furthermore, the antitumor effect of P–H/M was significantly improved compared with PTX-loaded micelles or HK-loaded micelles in vivo. P–H/M were more effective in inhibiting tumor proliferation, inducing tumor apoptosis, and decreasing the density of microvasculature. Moreover, bioimaging analysis showed that drug-loaded polymeric micelles could accumulate more in tumor tissues compared with the free drug. Our results suggested that P–H/M may have potential applications in breast cancer therapy.

Design and construction of self-hidden and pH-reversed targeting drug delivery nanovehicles via noncovalent interactions to overcome drug resistance

A convenient one-step method was used to construct self-hidden and pH-reversed targeting drug delivery nanovehicles using the host–guest interaction between β-CD and Ad, and borate formation between PBA and serinol.

Nanoprodrug of retinoic acid-modified paclitaxel

A nanoprodrug with high content (75%) and increased water solubility of paclitaxel was prepared from retinoic acid-modified paclitaxel.

Polymeric micelles of suberoylanilide hydroxamic acid to enhance the anticancer potential in vitro and in vivo

AIM

To improve the bioavailability and anticancer potential of suberoylanilide hydroxamic acid (SAHA) by developing a drug-loaded polymeric nanomicellar system.

METHODS

SAHA-loaded Poly(ethylene glycol)-block-poly(caprolactone) (PEG-PCL) micelles were developed, and physico-chemically characterized. In vitro cellular uptake, viability and apoptosis-inducing ability of the SAHA-PEG-PCL micelles were investigated. In vivo anticancer activity was evaluated in C57BL/6 mice-bearing tumor.

RESULTS

The SAHA-PEG-PCL micelles had optimum size (∼130 nm) with an entrapment efficiency of approximately 67%. The SAHA-PEG-PCL induced stronger cell cycle arrest in G2/M phase leading to higher rate of apoptosis compared to free SAHA. SAHA-PEG-PCL demonstrated significant tumor suppression compared to free SAHA in vivo.

CONCLUSION

The physicochemical properties and the antitumor efficacy of SAHA were improved by encapsulating in polymeric micelles.

Biodegradable mixed MPEG-SS-2SA/TPGS micelles for triggered intracellular release of paclitaxel and reversing multidrug resistance

In this study, a type of multifunctional mixed micelles were prepared by a novel biodegradable amphiphilic polymer (MPEG-SS-2SA) and a multidrug resistance (MDR) reversal agent (d-α-tocopheryl polyethylene glycol succinate, TPGS). The mixed micelles could achieve rapid intracellular drug release and reversal of MDR. First, the amphiphilic polymer, MPEG-SS-2SA, was synthesized through disulfide bonds between poly (ethylene glycol) monomethyl ether (MPEG) and stearic acid (SA). The structure of the obtained polymer was similar to poly (ethylene glycol)-phosphatidylethanolamine (PEG-PE). Then the mixed micelles, MPEG-SS-2SA/TPGS, were prepared by MPEG-SS-2SA and TPGS through the thin film hydration method and loaded paclitaxel (PTX) as the model drug. The in vitro release study revealed that the mixed micelles could rapidly release PTX within 24 h under a reductive environment because of the breaking of disulfide bonds. In cell experiments, the mixed micelles significantly inhibited the activity of mitochondrial respiratory complex II, also reduced the mitochondrial membrane potential, and the content of adenosine triphosphate, thus effectively inhibiting the efflux of PTX from cells. Moreover, in the confocal laser scanning microscopy, cellular uptake and 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assays, the MPEG-SS-2SA/TPGS micelles achieved faster release and more uptake of PTX in Michigan Cancer Foundation-7/PTX cells and showed better antitumor effects as compared with the insensitive control. In conclusion, the biodegradable mixed micelles, MPEG-SS-2SA/TPGS, could be potential vehicles for delivering hydrophobic chemotherapeutic drugs in MDR cancer therapy.

Advances in exploring alternative Taxol sources

The protection and sustainable utilization of natural resources are among the most pressing global problems of the 21st century.