Dual drug delivery of tamoxifen and quercetin: Regulated metabolism for anticancer treatment with nanosponges

Engineered Porous Beta-Cyclodextrin-Loaded Raloxifene Framework with Potential Anticancer Activity: Physicochemical Characterization, Drug Release, and Cytotoxicity Studies

Background

Cancer ranks as the second most common cause of mortality as depicted by the World Health Organization, with one in six deaths being cancer-related mortality. Taking the lead in females, breast cancer is the most common neoplasm. Raloxifene, a selective estrogen receptor modulator, has been utilized as a chemotherapeutic agent for the treatment of breast cancer in postmenopausal women. However, its poor aqueous solubility hinders its clinical applications. Beta-cyclodextrin-based framework is a novel class of nano-vectors that used to potentiate the solubility and dissolution rate of poorly soluble drugs.

Aim

The present study investigates the solubility and dissolution rate enhancement as well as the potential cytotoxic activity of raloxifene-loaded nanosponges formulation.

Methods

The fabrication and optimization of cyclodextrin nanosponges crosslinked with diphenyl carbonate was portrayed through stoichiometric selection of cyclodextrin-to-crosslinker ratio. The complexation phenomenon and nanosponges formation were validated using FTIR, PXRD, TEM, and SEM examination.

Results

Raloxifene-loaded nanosponges exhibited a 440±8.5 nm particle size, a negative zeta potential of 25.18±2.3 mV and a partial drug incorporation. Moreover, the drug loaded nanosponges demonstrated an in-vitro significantly enhanced dissolution behavior. Furthermore, the in-vitro cytotoxicity of the raloxifene-loaded nanosponges on MCF-7 breast cancer cell lines was statistically significant compared to the complex-free raloxifene.

Conclusion

The cytotoxic behavior provided evidence that the incorporation of raloxifene within the nanosponges structure enhanced its anticancer activity and represents a potential nanocarrier for anticancer agent delivery.

Inclusion complex of quercetin with sulfobutylether β-cyclodextrin: preparation, characterization, antioxidant and antibacterial activities and the inclusion mechanism

Quercetin (QCT) has a variety of pharmacological effects, such as antioxidant, antibacterial, anticancer, anticardiovascular and antiaging effects. However, its poor water solubility, stability and bioavailability limit its applications. The special structure of cyclodextrins and their derivatives with a hydrophobic inner cavity and hydrophilic outer wall can load a variety of hydrophobic drugs of a suitable size and shape, thereby improving the stability and solubility of these molecules. In this study, an inclusion complex of quercetin and sulfobutylether-β-cyclodextrin was prepared. It was characterized via FT-IR, UV, 1H NMR, XRD, DSC, and SEM analysis, which revealed the successful formation of the inclusion complex. In vitro biological activity estimations were carried out and the results indicated that the inclusion complex displayed higher antioxidative and antibacterial properties compared with free QCT. In addition, the mechanisms of inclusion were explored using 1H NMR analysis and docking calculations, thus providing a theoretical basis for obtaining an inclusion complex.

Application of Nanoparticles for Efficient Delivery of Quercetin in Cancer Cells

Quercetin (Qu, 3,5,7,3', 4'-pentahydroxyflavanone) is a natural polyphenol compound abundantly found in health food or plant-based products. In recent decades, Qu has gained significant attention in the food, cosmetic, and pharmaceutic industries owning to its wide beneficial therapeutic properties such as antioxidant, anti-inflammatory and anticancer activities. Despite the favorable roles of Qu in cancer therapy due to its numerous impacts on the cell signaling axis, its poor chemical stability and bioavailability, low aqueous solubility as well as short biological half-life have limited its clinical application. Recently, drug delivery systems based on nanotechnology have been developed to overcome such limitations and enhance the Qu biodistribution following administration. Several investigations have indicated that the nano-formulation of Qu enjoys more remarkable anticancer effects than its free form. Furthermore, incorporating Qu in various nano-delivery systems improved its sustained release and stability, extended its circulation time, enhanced its accumulation at target sites, and increased its therapeutic efficiency. The purpose of this study was to provide a comprehensive review of the anticancer properties of various Qu nano-formulation to augment their effects on different malignancies. Various targeting strategies for improving Qu delivery, including nanoliposomes, lipids, polymeric, micelle, and inorganic nanoparticle NPs, have been discussed in this review. The results of the current study illustrated that a combination of appropriate nano encapsulation approaches with tumor-oriented targeting delivery might lead to establishing QU nanoparticles that can be a promising technique for cancer treatment.

Water-borne synthesis of multi-responsive and biodegradable chitosan-crosslinked microgels: Towards self-assembled films with adaptable properties

The present study aims in the synthesis of new biodegradable stimuli-responsive microgels with controllable microstructure and with the ability to form cohesive films. Such self-assembled films by water evaporation at ambient conditions without any chemicals but just physical entanglements between soft colloid shell, present adaptable mechanical, adhesive and mechano-electrical properties. For that, oligo(ethylene glycol)-based stimuli-responsive microgels have been synthesized using biodegradable chitosan-methacrylates (Chi-MAs) with different degree of substitution (DS) as unique cross-linking agents by precipitation polymerization in water, for the first time. In all the cases, the microgels present thermo-responsiveness with hysteresis between heating and cooling cycles. However, this behavior is tuned and controlled using different types and amounts of Chi-MAs. In addition, the type of Chi-MA used can control microgels' microstructure as well as their enzymatic biodegradation. In addition, spontaneous cohesive films formation from colloidal aqueous dispersion with sol-gel transition is demonstrated. The films present tunable mechanical and adhesive properties through microgels' microstructure and enhanced mechano-electrical properties triggered by simple finger pressure (10-15 N). As self-supported films are able to encapsulate different types of active molecules, this study paves the way for suitable self-assembled microgel films for skincare applications as transdermal delivery systems.

Codelivery of Phytochemicals with Conventional Anticancer Drugs in Form of Nanocarriers

Anticancer drugs in monotherapy are ineffective to treat various kinds of cancer due to the heterogeneous nature of cancer. Moreover, available anticancer drugs possessed various hurdles, such as drug resistance, insensitivity of cancer cells to drugs, adverse effects and patient inconveniences. Hence, plant-based phytochemicals could be a better substitute for conventional chemotherapy for treatment of cancer due to various properties: lesser adverse effects, action via multiple pathways, economical, etc. Various preclinical studies have demonstrated that a combination of phytochemicals with conventional anticancer drugs is more efficacious than phytochemicals individually to treat cancer because plant-derived compounds have lower anticancer efficacy than conventional anticancer drugs. Moreover, phytochemicals suffer from poor aqueous solubility and reduced bioavailability, which must be resolved for efficacious treatment of cancer. Therefore, nanotechnology-based novel carriers are employed for codelivery of phytochemicals and conventional anticancer drugs for better treatment of cancer. These novel carriers include nanoemulsion, nanosuspension, nanostructured lipid carriers, solid lipid nanoparticles, polymeric nanoparticles, polymeric micelles, dendrimers, metallic nanoparticles, carbon nanotubes that provide various benefits of improved solubility, reduced adverse effects, higher efficacy, reduced dose, improved dosing frequency, reduced drug resistance, improved bioavailability and higher patient compliance. This review summarizes various phytochemicals employed in treatment of cancer, combination therapy of phytochemicals with anticancer drugs and various nanotechnology-based carriers to deliver the combination therapy in treatment of cancer.

Nano-drug co-delivery system of natural active ingredients and chemotherapy drugs for cancer treatment: a review

Chemotherapy drugs have been used for a long time in the treatment of cancer, but serious side effects are caused by the inability of the drug to be solely delivered to the tumor when treating cancer with chemotherapy. Natural products have attracted more and more attention due to the antitumor effect in multiple ways, abundant resources and less side effects. Therefore, the combination of natural active ingredients and chemotherapy drugs may be an effective antitumor strategy, which can inhibit the growth of tumor and multidrug resistance, reduce side effects of chemotherapy drugs. Nano-drug co-delivery system (NDCDS) can play an important role in the combination of natural active ingredients and chemotherapy drugs. This review provides a comprehensive summary of the research status and application prospect of nano-delivery strategies for the combination of natural active ingredients and chemotherapy drugs, aiming to provide a basis for the development of anti-tumor drugs.

Effect of nanovesicular surface-functionalization via chitosan and/or PEGylation on cytotoxicity of tamoxifen in induced-breast cancer model

AIMS

The effect of surface-modification of Tamoxifen (Tam)-loaded-niosomes on drug cytotoxicity and bio-distribution, via functionalization with chitosan and/or PEGylation, was investigated.

MATERIALS AND METHODS

Tam-loaded hybrid-nanocarriers (Tam-loaded niosomes, chitosomes, PEGylated niosomes, and PEGylated chitosomes) were formulated and characterized.

KEY FINDINGS

Chitosanization with/without PEGylation proved to selectively enhance Tam-release at the cancerous-acidic micromilieu. Cytotoxic activity study showed that Tam-loaded PEGylated niosomes had a lower IC₅₀ value on MCF-7 cell line (0.39, 0.35, and 0.27 times) than Tam-loaded PEGylated chitosomes, Tam-loaded niosomes, and Tam-loaded chitosomes, respectively. Cell cycle analysis showed that PEGylation and/or Chitosanization significantly impact Tam efficiency in inducing apoptosis, with a preferential influence of PEGylation over chitosanization. The assay of Annexin-V/PI double staining revealed that chitosanized-nanocarriers had a significant role in increasing the incidence of apoptosis over necrosis. Besides, PEGylated-nanocarriers increased apoptosis, as well as total death and necrosis percentages more than what was shown from free Tam. Moreover, the average changes in both Bax/Bcl-2 ratio and Caspase 9 were best improved in cells treated by Tam-loaded PEGylated niosomes over all other formulations. The in-vivo study involving DMBA-induced-breast cancer rats revealed that PEGylation made the highest tumor-growth inhibition (84.9 %) and breast tumor selectivity, while chitosanization had a lower accumulation tendency in the blood (62.3 ng/ml) and liver tissues (103.67 ng/ml). The histopathological specimens from the group treated with Tam-loaded PEGylated niosomes showed the best improvement over other formulations.

SIGNIFICANCE

All these results concluded the crucial effect of both PEGylation and chitosan-functionalization of Tam-loaded niosomes in enhancing effectiveness, targetability, and safety.

Quercetin- and rutin-based nano-formulations for cancer treatment: A systematic review of improved efficacy and molecular mechanisms

BACKGROUND

Natural products, with incredible chemical diversity, have been widely studied for their antitumor potential. Quercetin (QU) and quercetin glycoside (rutin), both polyphenolic flavonoids, stick out amongst the natural products, through various studies. Rutin (RU) and its aglycone (QU) have various biological properties that include antioxidant, anti-inflammatory, and anticarcinogenic activities. However, several side effects have restricted the efficacy of these polyphenolic flavonoids, which makes it necessary to use new strategies involving low and pharmacological doses of QU and RU, either alone or in combination with other anticancer drugs.

PURPOSE

The aim of this study is to present a comprehensive and critical evaluation of the anticancer ability of different nano-formulations of RU and QU for improved treatment of various malignancies.

METHODS

Studies were recognized via systematic searches of ScienceDirect, PubMed, and Scopus databases. Eligibility checks were conducted based upon predefined selection criteria. Ninety articles were included in this study.

RESULTS

There was conclusive evidence for the association between anticancer activity and treatment with RU or QU. Furthermore, studies indicated that nano-formulations of RU and QU have greater anticancer activities in comparison to either agent alone, which leads to increased efficiency for treating cancer.

CONCLUSION

The results of this systematic review demonstrate the anticancer activities of nano-formulations of RU and QU and their molecular mechanisms through preclinical studies. This paper also attempts to contribute to further research by addressing the current limitations/challenges and proposing additional studies to realize the full potential of RU- and QU-based formulations for cancer treatment.

Inhibition of growth and lung metastasis of breast cancer by tumor-homing triple-bioresponsive nanotherapeutics

Lung metastasis of breast cancer is a leading cause of cancer-related death in women. Herein, we attempted to simultaneously inhibit the growth and lung metastasis of breast cancer by delivering quercetin (QU) using LyP-1-functionalized regenerated silk fibroin-based nanoparticles (NPs). The generated LyP-1-QU-NPs had a desirable diameter (203.2 nm) and a negatively charged surface (-12.7 mV). Interestingly, these NPs exhibited intrinsic responsibilities when triggered by various stimulating factors in the tumor microenvironment (acidic pH, reactive oxygen species, and glutathione). In vitro experiments revealed that the introduction of LyP-1 to the NP surface could significantly increase their cellular uptake efficiencies by 4 T1 cells, and facilitate their accumulation in mitochondria. Moreover, LyP-1-QU-NPs showed the strongest mitochondrial damage effect among all the treatment groups. We also found that LyP-1-QU-NPs not only exhibited excellent pro-apoptotic activities but also presented strong inhibitory effects on cell mobility (migration and invasion) through anti-glycolysis and pro-autophagy. Mice experiments confirmed that LyP-1-QU-NPs could efficiently inhibit the in situ growth of breast tumors and further restrict their lung metastasis. Collectively, our results demonstrate that LyP-1-QU-NPs, which integrates the functions of tumor cell targeting, mitochondria targeting, bioresponsive drug release, pro-apoptosis, and anti-mobility, can be developed as a promising nanotherapeutic for the effective treatment of breast cancer and its lung metastasis.

Dual Role of Doxorubicin for Photopolymerization and Therapy

In this study, we report dual roles for doxorubicin (DOX), which can serve as an antitumor drug as well as a cocatalyst for a photoliving radical polymerization. DOX enhances the polymerization rates of a broad range of monomers, including acrylamide, acrylate, and methacrylates, allowing for high monomer conversion and well-defined molecular weights under irradiation with a blue light-emitting diode light (λ_max = 485 nm, 2.2 mW/cm²). Utilizing this property, the photopolymerization of N,N-diethylacrylamide was performed in the presence of a poly(oligo(ethylene glycol) methyl ether acrylate) macroreversible addition-fragmentation chain transfer (macroRAFT) agent to prepare polymeric nanoparticles via aqueous polymerization-induced self-assembly (PISA). By varying the monomer:macroRAFT ratio, spherical polymeric nanoparticles of various diameters could be produced. Most notably, DOX was successfully encapsulated into the hydrophobic core of nanoparticles during the PISA process. The DOX-loaded nanoparticles were effectively uptaken into tumor cells and significantly inhibited the proliferation of tumor cells, demonstrating that the DOX bioactivity was not affected by the polymerization reaction.

Quercetin Loaded Nanoparticles in Targeting Cancer: Recent Development

The spread of metastatic cancer cell is the main cause of death worldwide. Cellular and molecular basis of the action of phytochemicals in the modulation of metastatic cancer highlights the importance of fruits and vegetables. Quercetin is a natural bioflavonoid present in fruits, vegetables, seeds, berries, and tea. The cancer-preventive activity of quercetin is well documented due to its anti-inflammatory, anti-proliferative and anti-angiogenic activities. However, poor water solubility and delivery, chemical instability, short half-life, and low-bioavailability of quercetin limit its clinical application in cancer chemoprevention. A better understanding of the molecular mechanism of controlled and regulated drug delivery is essential for the development of novel and effective therapies. To overcome the limitations of accessibility by quercetin, it can be delivered as nanoconjugated quercetin. Nanoconjugated quercetin has attracted much attention due to its controlled drug release, long retention in tumor, enhanced anticancer potential, and promising clinical application. The pharmacological effect of quercetin conjugated nanoparticles typically depends on drug carriers used such as liposomes, silver nanoparticles, silica nanoparticles, PLGA (Poly lactic-co-glycolic acid), PLA (poly(D,L-lactic acid)) nanoparticles, polymeric micelles, chitosan nanoparticles, etc. In this review, we described various delivery systems of nanoconjugated quercetin like liposomes, silver nanoparticles, PLGA (Poly lactic-co-glycolic acid), and polymeric micelles including DOX conjugated micelles, metal conjugated micelles, nucleic acid conjugated micelles, and antibody-conjugated micelles on in vitro and in vivo tumor models; as well as validated their potential as promising onco-therapeutic agents in light of recent updates.

CD59 receptor targeted delivery of miRNA-1284 and cisplatin-loaded liposomes for effective therapeutic efficacy against cervical cancer cells

Co-delivery of two different therapeutics (miRNA-1284 and cisplatin (CDDP)) into the cancer cells in a single nanocarrier provides new dimension to the cancer treatment. In this study, we have designed the CD59sp-conjugated miRNA-1284/cisplatin(CDDP)-loaded liposomes for the enhanced therapeutic effect against cervical cancers. Compared with miRNA-1284/CDDP-loaded liposomes (LP-miCDDP), CD59 antibody-conjugated LP-miCDDP (CD/LP-miCDDP) showed a significantly higher cytotoxicity in HeLa cells. Notably, MiR-1284 showed a typical concentration-dependent cell killing effect in the cervical cancer cells owing to the downregulation of HMGB1. Flow cytometer analysis showed that CD/LP-miCDDP resulted in maximum apoptosis effect (~ 60%) compared to CDDP (~ 20%) or miR-1284 (~ 12%) treated cells indicating the superior anticancer effect in the cancer cells. Importantly, CD/LP-miCDDP significantly prolonged the blood circulation of encapsulated drug in rats with AUC(o-t) of CD/LP-miCDDP showed a 6.9 fold higher value than that of free CDDP. Similarly, CD/LP-miCDDP showed an eightfold decrease in the clearance (CL) and 3.6-fold higher t1/2 compared to that of free CDDP. Overall, results demonstrated that targeted and synergistic co-delivery of therapeutic components could be promising in cervical cancer therapy.

Dual drug-loaded biodegradable Janus particles for simultaneous co-delivery of hydrophobic and hydrophilic compounds

Bicompartmental Janus particles have many advantages in drug delivery, including co-delivery of two compounds with varying solubilities, differential release kinetics, and two surfaces available for targeting ligands. We present a novel strategy using the double emulsion method for the coencapsulation and staggered release of a hydrophobic and hydrophilic drug from anisotropic PLGA/PCL Janus particles, as well as a UV detection method to measure the release of two different compounds from Janus particles. Curcumin and quercetin were chosen as the model hydrophobic compounds for drug loading studies, while acetaminophen (APAP) and naproxen were chosen as the model hydrophilic–hydrophobic drug pair for encapsulation methods and drug loading. Also, a similar double emulsion method was also applied for PLGA/Preicrol® Janus particles containing Doxorubicin and Curcumin. Hydrophobic drugs were encapsulated by the single O/W emulsion technique. Hydrophilic compounds required special modifications due to their poor oil solubility and tendency to escape to the outer aqueous phase during the emulsification and solvent evaporation steps. In total, three different strategies for incorporating hydrophilic drugs were employed: (1) O/W emulsion with partially water miscible solvent, (2) O/W emulsion with co-solvent (i.e. acetone, methanol, ethanol), or (3) W/O/W double emulsion. The encapsulation efficiencies and drug loading percentages were measured using UV/Vis spectroscopy and compared for the different synthesis methods. It was found that the double emulsion method resulted in the highest encapsulation efficiency and drug loading of the hydrophilic drug.

CDI cross-linked β-cyclodextrin nanosponges of paliperidone: synthesis and physicochemical characterization

Paliperidone (PLP) is an antipsychotic drug indicated for treatment and management of schizophrenia. The current study demonstrates potential of PLP-loaded β-cyclodextrin-based nanosponges (CDNS) for solubility enhancement and prolonged release of PLP. The inclusion complexes of PLP with carbonyldiimidazole (CDI) cross-linked nanosponges were synthesized. The drug-loaded CDNS were characterized for particle size, zeta potential, encapsulation efficiency, stability study, in vitro drug release studies. The interaction of PLP with CDNS was ascertained by FTIR, DSC and PXRD studies. The particle size and zeta potential values were sufficient to obtain stable formulations. Solubility was significantly increased and in vitro drug release studies revealed prolonged release of PLP from the CDNS for 6 h. PXRD study revealed that the crystallinity of PLP was decreased due to complexation with the CDNS. Thus, cyclodextrin-based nanosponges represent a novel approach for solubility enhancement and improved dissolution of selected model drug PLP.

Traditional Chinese medicine-combination therapies utilizing nanotechnology-based targeted delivery systems: a new strategy for antitumor treatment

Cancer is a major public health problem, and is now the world’s leading cause of death. Traditional Chinese medicine (TCM)-combination therapy is a new treatment approach and a vital therapeutic strategy for cancer, as it exhibits promising antitumor potential. Nano-targeted drug-delivery systems have remarkable advantages and allow the development of TCM-combination therapies by systematically controlling drug release and delivering drugs to solid tumors. In this review, the anticancer activity of TCM compounds is introduced. The combined use of TCM for antitumor treatment is analyzed and summarized. These combination therapies, using a single nanocarrier system, namely codelivery, are analyzed, issues that require attention are determined, and future perspectives are identified. We carried out a systematic review of >280 studies published in PubMed since 1985 (no patents involved), in order to provide a few basic considerations in terms of the design principles and management of targeted nanotechnology-based TCM-combination therapies.

Threatening cancer with nanoparticle aided combination oncotherapy

Employing combination therapy has become obligatory in cancer cases exhibiting high tumor load, chemoresistant tumor population, and advanced disease stages. Realization of this fact has now led many of the combination oncotherapies to become an integral part of anticancer regimens. Combination oncotherapy may encompass a combination of anticancer agents belonging to a similar therapeutic category or that of different therapeutic categories (e.g. chemotherapy + gene therapy). Differences in the physicochemical properties, pharmacokinetics and biodistribution pattern of different payloads are the major constraints that are faced by combination chemotherapy. Concordant efforts in the field of nanotechnology and oncology have emerged with several approaches to solve the major issues encountered by combination therapy. Unique colloidal behaviors of various types of nanoparticles and differential targeting strategies have accorded an unprecedented ability to optimize combination oncotherapeutic delivery. Nanocarrier based delivery of the various types of payloads such as chemotherapeutic agents and other anticancer therapeutics such as small interfering ribonucleic acid (siRNA), chemosensitizers, radiosensitizers, and antiangiogenic agents have been addressed in the present review. Various nano-delivery systems like liposomes, polymeric nanoparticles, polymerosomes, dendrimers, micelles, lipid based nanoparticles, prodrug based nanocarriers, polymer-drug conjugates, polymer-lipid hybrid nanoparticles, carbon nanotubes, nanosponges, supramolecular nanocarriers and inorganic nanoparticles (gold nanoparticles, silver nanoparticles, magnetic nanoparticles and mesoporous silica based nanoparticles) that have been extensively explored for the formulation of multidrug delivery is an imperative part of discussion in the review. The present review features the outweighing benefits of combination therapy over mono-oncotherapy and discusses several existent nanoformulation strategies that facilitate a successful combination oncotherapy. Several obstacles that may impede in transforming nanotechnology-based combination oncotherapy from bench to bedside, and challenges associated therein have also been discussed in the present review.

Enhancing the Therapeutic Efficacy of Tamoxifen Citrate Loaded Span-Based Nano-Vesicles on Human Breast Adenocarcinoma Cells

Serious adverse effects and low selectivity to cancer cells are the main obstacles of long term therapy with Tamoxifen (Tmx). This study aimed to develop Tmx-loaded span-based nano-vesicles for delivery to malignant tissues with maximum efficacy. The effect of three variables on vesicle size (Y₁), zeta potential (Y₂), entrapment efficiency (Y₃) and the cumulative percent release after 24 h (Y₄) were optimized using Box-Behnken design. The optimized formula was prepared and tested for its stability in different storage conditions. The observed values for the optimized formula were 310.2 nm, - 42.09 mV, 75.45 and 71.70% for Y₁, Y₂, Y₃, and Y₄, respectively. The examination using electron microscopy confirmed the formation of rounded vesicles with distinctive bilayer structure. Moreover, the cytotoxic activity of the optimized formula on both breast cancer cells (MCF-7) and normal cells (BHK) showed enhanced selectivity (9.4 folds) on cancerous cells with IC₅₀ values 4.7 ± 1.5 and 44.3 ± 1.3 μg/ml on cancer and normal cells, respectively. While, free Tmx exhibited lower selectivity (2.5 folds) than optimized nano-vesicles on cancer cells with IC₅₀ values of 9.0 ± 1.1 μg/ml and 22.5 ± 5.3 μg/ml on MCF-7 and BHK cells, respectively. The promising prepared vesicular system, with greater efficacy and selectivity, provides a marvelous tool to overcome breast cancer treatment challenges.

Preparation and in vitro and in vivo evaluation of quercetin-loaded mixed micelles for oral delivery

Quercetin (QT) is a plant polyphenol with various pharmacological properties. However, the low water solubility limits its therapeutic efficacy. In the present study, QT-loaded sodium taurocholate-Pluronic P123 (QT-loaded ST/P123) mixed micelles were developed and characterized, and the effect of the formulation on improving the water solubility of QT was investigated. QT-loaded ST/P123 mixed micelles were prepared by thin film hydration-direct dissolution and optimized by uniform design. The optimal formulation possessed high drug loading (12.6%) and entrapment efficiency (95.9%) in small (16.20 nm) spherically-shaped micelles. A low critical micelle concentration indicated that the micelles were stable, and they showed a sustained release pattern, as determined in vitro in simulated gastric fluid and intestinal fluid. Pharmacokinetic evaluation showed the Cmax and AUC0–24 were 1.8-fold and 1.6-fold higher than the QT suspension. The present results indicate that QT-loaded ST/P123 micelles are potential candidates to improve the solubility and oral bioavailability of QT.

Paclitaxel and quercetin nanoparticles co-loaded in microspheres to prolong retention time for pulmonary drug delivery

High drug resistance, poor water solubility, short half-life, and low local drug concentration are obstacles for successful delivery of chemotherapeutic drugs for lung cancer. A new method involving the use of nanoparticles (NPs) for pulmonary delivery is proposed. However, use of NPs is limited by the particle size range for pulmonary drug delivery considering that NPs cannot be deposited directly into the lungs. NPs polymerized into microspheres (polymeric microspheres, PMs) will result in suitable particle sizes and retain the advantages of nanodrugs after redispersion when applied in pulmonary delivery. We report the development of novel NPs in the form of PMs loaded with paclitaxel (PTX) and quercetin (QUE) double drugs based on the synthesis of oleic acid-conjugated chitosan (OA-CTS) for pulmonary delivery. This approach is aimed toward prolonging PTX retention time in the presence of QUE and bypassing P-glycoprotein drug efflux pumps. NPs loaded with PTX or QUE were prepared with 11% substitution degree using OA-CTS as the carrier by ionic cross-linking method, which NPs loaded with PTX or QUE were used in the preparation of PMs by spray-drying. The diameters of the PMs ranged from 1 to 5 μm which had uniform size range. Scanning electron microscopy showed that PMs were polymers formed by a large number of NPs and readily redispersed (after redispersion, size of NPs ranged between 250 and 350 nm) in water within 1 h. PMs displayed slow-release characteristics at pH 4.5 and 7.4. The in vivo pharmacokinetic and biodistribution studies suggested that PMs exhibit prolonged circulation time and a markedly high accumulation in the lung. The obtained results indicate that PMs can serve as a promising pulmonary delivery system for combined pharmacotherapy using hydrophobic anticancer drugs.

Nanosponge Tunability in Size and Crosslinking Density

We describe a protocol for the synthesis of linear polyesters containing pendant epoxide functionality and their incorporation into a nanosponge with controlled dimensions. This approach begins with synthesis of a functionalized lactone which is key to the pendant functionalization of the resulting polymer. Valerolactone (VL) and allyl-valerolactone (AVL) are then copolymerized using ring-opening polymerization. Post-polymerization modification is then used to install an epoxide moiety on some or all of the pendant allyl groups. Epoxy-amine chemistry is employed to form nanoparticles in a dilute solution of both polymer and small molecule diamine crosslinker based on the desired nanosponge size and crosslinking density. Nanosponge sizes can be characterized by transmission electron microscopy (TEM) imaging to determine the dimension and distribution. This method provides a pathway by which highly tunable polyesters can create tunable nanoparticles, which can be used for small molecule drug encapsulation. Due to the nature of the backbone, these particles are hydrolytically and enzymatically degradable for a controlled release of a wide range of hydrophobic small molecules.

The reversion of anti-cancer drug antagonism of tamoxifen and docetaxel by the hyaluronic acid-decorated polymeric nanoparticles

Docetaxel (DTX) and tamoxifen (TMX) are first-line drugs used to treat breast cancer. However when used in combination, they produce antagonism because of their differential metabolic pathways. In order to prevent this antagonism, an amphiphilic copolymer, cholesterol modified hyaruronic acid (HA-CHOL), was synthesized for investigating the co-delivery of TMX and DTX. In vitro drug release experiment of the Co-encapsulated (encapsulated DTX+TMX) nanoparticles (Co-NPs) revealed that NPs with unique release mechanism can markedly reduce the release of these drugs in the circulatory system. However, when reaching in cell, TMX can release rapidly to prevent DTX from coming into contact with metabolizing enzymes. In vitro cytotoxicity experiment revealed that the Co-NPs exhibited a significant synergistic effect for inhibiting the proliferation of the cancer cell lines A549, MCF7 and S180. NPs carrying Coumarin-6(Cou6) exhibited increased cellular uptake compared with Cou6 solution at similar drug concentrations. As an in vivo treatment of xenograft tumors involving 180 cells, the Co-NPs displayed a clear tumor-inhibiting effect. This led us to conclude that the reversion of drug antagonism by NPs was attributed to the increased stability of the nanoparticles in the blood circulation, the efficient cellular uptake, the hierarchical drug metabolism in the tumor and the good and orderly delivery of the drugs to the tumor tissue.

Co-delivery of vincristine and quercetin by nanocarriers for lymphoma combination chemotherapy

PURPOSE

Chemotherapy is the current standard treatment for Non-Hodgkin's lymphoma (NHL). Combination therapy is emerging as an important strategy for a better long-term prognosis with decreased side effects, maximized therapeutic effect. The aim of this study is to deliver vincristine (VCR) and quercetin (QU) with synergistic drug ratios through lipid-polymeric nanocarriers (LPNs) for the lymphoma combination chemotherapy METHODS: In this present study, we constructed VCR and QU dual-loaded LPNs (VCR/QU LPNs) and investigated their antitumor efficacy in vitro cell culture models and a tumor xenograft mouse model.

RESULTS

The formulated VCR/QU LPNs exhibited nano-size, negative zeta potential with sustained release profile in vitro. The dual drug loaded LPNs exhibited the best antitumor efficacy in vitro and in vivo.

CONCLUSION

It could be concluded that VCR/QU LPNs can combine the efficiency of these two drugs, bring about synergistic effect. Co-encapsulation of VCR and QN in the same LPNs has potential as a novel therapeutic approach to overcome chemo-resistant lymphoma.

Mixed poly(vinyl pyrrolidone)-based drug-loaded nanomicelles shows enhanced efficacy against pancreatic cancer cell lines

We report in this paper on the enhanced efficacy of a physical mixture of two single anti-cancer loaded nanomicelles against PANC-1 and BxPC-3. Poly(vinyl pyrrolidone-b-polycaprolactone) (PVP-b-PCL) and poly(vinyl pyrrolidone-b-poly(dioxanone-co-methyl dioxanone)) (PVP-b-P(DX-co-MeDX)) were synthesized and successfully loaded with various anti-cancer drugs - gemcitabine (GEM), doxorubicin.HCl (DOX.HCl), doxorubicin.NH₂ (DOX), 5-fluorouracil (5-FU) and paclitaxel (PTX). Spherical micelles of size 160-477 nm were obtained as characterized by DLS while sizes determined by TEM were in the range 140-250 nm. The hydrophobic drugs had a higher loading percentage efficiency compared to hydrophilic drugs in the trend PTX>DOX>5-FU>GEM>DOX.HCl whereas the drug release pattern followed the reverse trend in accordance with decreased polymer-drug interaction as quantified by the binding constant and micellar drug location. Cellular uptake studies showed that nanomicelles are taken up by pancreatic cancer cells into the cytoplasm and nucleus. The free nanomicelles were confirmed to be non-cytotoxic. A physical mixture of GEM loaded micelles and DOX.HCl loaded micelles of comparable size showed significantly higher cytotoxicity than either the free drug mixture or the individual single drug loaded micelles as confirmed by their IC₅₀ values.

Co-delivery of paclitaxel and TOS-cisplatin via TAT-targeted solid lipid nanoparticles with synergistic antitumor activity against cervical cancer

BACKGROUND

Cervical cancer is a major world health problem for women. Currently, cancer research focuses on improving therapy for cervical cancer using various treatment options such as co-delivery of chemotherapeutic agents by nanocarriers.

PURPOSE

The aim of this study was to develop trans-activating transcriptional activator (TAT)-modified solid lipid nanoparticles (SLNs) for co-delivery of paclitaxel (PTX) and α-tocopherol succinate-cisplatin prodrug (TOS-CDDP) (TAT PTX/TOS-CDDP SLNs) in order to achieve synergistic antitumor activity against cervical cancer.

METHODS

Lipid prodrug of CDDP (TOS-CDDP) and TAT-containing polyethylene glycol-distearoyl-phosphatidylethanolamine (TAT-PEG-DSPE) were synthesized. TAT PTX/TOS-CDDP SLNs were prepared by emulsification and solvent evaporation method. Physicochemical characteristics of SLNs such as size, morphology, and release profiles were explored. In vitro and in vivo studies were carried out to assess the efficacy of their antitumor activity in target cells.

RESULTS

TAT PTX/TOS-CDDP SLNs could be successfully internalized by HeLa cells and showed a synergistic effect in the suppression of cervical tumor cell growth. They exhibited high tumor tissue accumulation, superior antitumor efficiency, and much lower toxicity in vivo.

CONCLUSION

The present study indicates that the co-delivery system provides a promising platform as a combination therapy for the treatment of cervical cancer, and possibly other types of cancer as well.

Quercetin as an Emerging Anti-Melanoma Agent: A Four-Focus Area Therapeutic Development Strategy

Replacing current refractory treatments for melanoma with new prevention and therapeutic approaches is crucial in order to successfully treat this aggressive cancer form. Melanoma develops from neural crest cells, which express tyrosinase – a key enzyme in the pigmentation pathway. The tyrosinase enzyme is highly active in melanoma cells and metabolizes polyphenolic compounds; tyrosinase expression thus makes feasible a target for polyphenol-based therapies. For example, quercetin (3,3′,4′,5,7-pentahydroxyflavone) is a highly ubiquitous and well-classified dietary polyphenol found in various fruits, vegetables, and other plant products including onions, broccoli, kale, oranges, blueberries, apples, and tea. Quercetin has demonstrated antiproliferative and proapoptotic activity in various cancer cell types. Quercetin is readily metabolized by tyrosinase into various compounds that promote anticancer activity; additionally, given that tyrosinase expression increases during tumorigenesis, and its activity is associated with pigmentation changes in both early- and late-stage melanocytic lesions, it suggests that quercetin can be used to target melanoma. In this review, we explore the potential of quercetin as an anti-melanoma agent utilizing and extrapolating on evidence from previous in vitro studies in various human malignant cell lines and propose a “four-focus area strategy” to develop quercetin as a targeted anti-melanoma compound for use as either a preventative or therapeutic agent. The four areas of focus include utilizing quercetin to (i) modulate cellular bioreduction potential and associated signaling cascades, (ii) affect transcription of relevant genes, (iii) regulate epigenetic processes, and (iv) develop effective combination therapies and delivery modalities/protocols. In general, quercetin could be used to exploit tyrosinase activity to prevent, and/or treat, melanoma with minimal additional side effects.

Evaluation of host-guest system to enhance the tamoxifen efficiency

Hydrophobic drugs can absorb as guest molecules inside the cavity of cyclodextrins as host sites. So, forming the drug-cyclodextrin complex can exert a profound effect on the physicochemical and biological properties of the drugs. According to these advantages, in this study, we synthesized the tamoxifen (TMX) loaded cyclodextrin (CD)-conjugated MNPs to evaluate simultaneously the cytotoxicity and sustained release as well as hepatoprotective effect of this nanomedicine. The average size of Fe₃O₄-DPA-PEG-CD-TMX NPs was approximately 31 nm. By energy-dispersive X-ray spectroscopy (EDS), it was revealed that Fe₃O₄ constitutes 14.34% of the composition of modified MNPs. In the other words, nearly 85% of Fe₃O₄-DPA-PEG-CD NPs are made of dopamine (DPA), polyethylene glycol (PEG) and β-cyclodextrin (β-CD). The TMX loaded MNPs (with entrapment efficiency of 33 mg TMX per unit CD (mg) and loading efficiency of 87.5%) showed sustained liberation of TMX molecules (with 91% release in 120 h). Cytotoxicity assay and apoptosis assay by TUNEL analysis revealed that the engineered Fe₃O₄-DPA-PEG-CD-TMX NPs were able to significantly inhibit the MCF-7 breast cancer cells. According to effect of CD on TMX sustained release, it was found that CD can decrease the hepatotoxicity induced by TMX nearly 30%. Based upon these findings, we suggest the Fe₃O₄-DPA-PEG-CD-TMX NPs as an effective multifunctional nanomedicine with simultaneous therapeutic and hepatoprotective effects.