Simple preparation and greatly improved oral bioavailability: The supersaturated drug delivery system of quercetin based on PVP K30.

Quercetin, as a representative flavonoid, is widely present in daily diet and has been developed as a dietary supplement due to its beneficial physiological activities. However, the application of quercetin is limited due to its poor water solubility and extensive metabolism. So far, the nano-drug delivery systems designed to improve its bioavailability generally have the shortcomings of low drug loading content and difficulty in industrial production. In order to tackle these problems, quercetin supersaturated drug delivery system (QSDDS) was successfully prepared using solvent method, for which PVP K30 was employed as a crystallization and precipitation inhibitor to maintain the supersaturated state of quercetin in aqueous system. The obtained QSDDS, with a relative high drug loading content of 13%, could quickly disperse in water and form colloidal system with the mean particle size of about 200 nm, meanwhile induce the generation of supersaturated quercetin solution more than 12 h. In vivo pharmacokinetic study proved that QSDDS achieved a high absolute bioavailability of 36.05%, 10 times as that of physical quercetin suspension, which was dose-dependent with higher bioavailability at higher dose. Considering the simple preparation method, QSDDS provided a feasible strategy and a simple way to improve oral absorption of insoluble flavonoids.

Ginsenoside Rb1 stabilized and paclitaxel / protopanaxadiol co-loaded nanoparticles for synergistic treatment of breast tumor.

Ginsenosides are the major and key components for ginseng to exert its wide and beneficial therapeutic efficacy in clinic. Meanwhile, many ginsenosides and their metabolites showed in vitro an in vivo anti-tumor activity, among which ginsenoside Rb1 has attracted much attention due to its good solubility and amphipathy. In this study, the self-assembly behavior of Rb1 was investigated and the Rb1 nano-assembly could further stabilize or encapsulated hydrophobic drugs such as protopanaxadiol (PPD) and paclitaxel (PTX) to form nanoparticles, based on which, a natural nanoscale drug delivery system, ginsenoside Rb1 stabilized and PTX/PPD co-loaded nanoparticles (GPP NPs) were prepared. The resultant GPP NPs exhibited a small particle size of 126.2 nm, a narrow size distribution (PDI=0.145), and a zeta potential of -27.3 mV. PTX loading content was 11.06% with an encapsulation efficiency of 93.86%. GPP NPs were spherical and stable in normal saline, 5% glucose, PBS, plasma, or on-shelf storage for 7 days. Both PTX and PPD existed in an amorphous state in GPP NPs and were released in a sustained pattern. GPP NPs showed 10-fold higher in vitro anti-tumor activity of than PTX injections. In the in vivo experiment, GPP NPs achieved a much higher tumor inhibition rate than PTX injections (64.95% vs 43.17%, P < 0.01) and certain tumor target ability. In conclusion, GPP NPs had significantly enhanced anti-tumor efficacy and improved tumor microenvironment, thus were promising to be developed into a novel anti-tumor agent for the treatment of breast tumor.

A γ-Glutamyl Transpeptidase (GGT)-Triggered Charge Reversal Drug-Delivery System for Cervical Cancer Treatment: In Vitro and In Vivo Investigation.

Neutral/negatively charged nanoparticles are beneficial to reduce plasma protein adsorption and prolong their blood circulation time, while positively charged nanoparticles easily transverse the blood vessel endothelium into a tumor and easily penetrate the depth of the tumor via transcytosis. Γ-Glutamyl transpeptidase (GGT) is overexpressed on the external surface of endothelial cells of tumor blood vessels and metabolically active tumor cells. Nanocarriers modified by molecules containing γ-glutamyl moieties (such as glutathione, G-SH) can maintain a neutral/negative charge in the blood, as well as can be easily hydrolyzed by the GGT enzymes to expose the cationic surface at the tumor site, thus achieving good tumor accumulation via charge reversal. In this study, DSPE-PEG2000-GSH (DPG) was synthesized and used as a stabilizer to generate paclitaxel (PTX) nanosuspensions for the treatment of Hela cervical cancer (GGT-positive). The obtained drug-delivery system (PTX-DPG nanoparticles) was 164.6 ± 3.1 nm in diameter with a zeta potential of -9.85 ± 1.03 mV and a high drug-loaded content of 41.45 ± 0.7%. PTX-DPG NPs maintained their negative surface charge in a low concentration of GGT enzyme (0.05 U/mL), whereas they showed a significant charge-reversal property in the high-concentration solution of GGT enzyme (10 U/mL). After intravenous administration, PTX-DPG NPs mainly accumulated more in the tumor than in the liver, achieved good tumor-targetability, and significantly improved anti-tumor efficacy (68.48% vs. 24.07%, tumor inhibition rate, p < 0.05 in contrast to free PTX). This kind of GGT-triggered charge-reversal nanoparticle is promising to be a novel anti-tumor agent for the effective treatment of such GGT-positive cancers as cervical cancer.

A simple but efficient tumor-targeted nanoparticle delivery system constructed by oleic acid.

Oleic acid (OA) is a kind of monounsaturated omega-3 fatty acid that abounds in plants and animals which can induce apoptosis and has broad-spectrum inhibitory activity against a variety of tumor cell lines. However, OA is quite insoluble and thus inconvenient to be efficiently delivered in vivo. In this work, OA was fabricated into nanoparticles to generate OA elastic nanoparticles (OA-ENPs) with a particle size of 185.6 nm and good stability in various physiological media. OA-ENPs alone achieved a high tumor inhibition rate of 60.3% without significant side effect. More surprisingly, the resultant OA-ENPs displayed dose-dependent tumor targetability. Low dose of OA-ENPs (10 mg/kg) mainly distributed in the liver after intravenous injection, while high dose of OA-ENPs mainly distributed in tumor. At the high dose of 90 mg/kg, OA-ENPs accumulation in tumor reached nearly twice as that in the liver. Here we provide a simple but effective way to achieve excellent tumor targetability without the need of any surface modification of nanoparticles.

Improved Therapeutic Efficacy of CBD with Good Tolerance in the Treatment of Breast Cancer through Nanoencapsulation and in Combination with 20(S)-Protopanaxadiol (PPD).

Cannabidiol (CBD), a nonpsychoactive major component derived from Cannabis sativa, widely used in neurodegenerative diseases, has now been proven to have growth inhibitory effects on many tumor cell lines, including breast tumors. Meanwhile CBD can effectively alleviate cancer-associated pain, anxiety, and depression, especially tumor cachexia, thus it is very promising as an anti-tumor drug with unique advantages. 20(S)-Protopanaxadiol (PPD) derived from the best-known tonic Chinese herbal medicine Ginseng was designed to be co-loaded with CBD into liposomes to examine their synergistic tumor-inhibitory effect. The CBD-PPD co-loading liposomes (CP-liposomes) presented a mean particle size of 138.8 nm. Further glycosyl-modified CP-liposomes (GMCP-liposomes) were prepared by the incorporation of n-Dodecyl ß-D-maltoside (Mal) into the liposomal bilayer with glucose residue anchored on the surface to act as a ligand targeting the GLUT1 receptor highly expressed on tumor cells. In vivo studies on murine breast tumor (4T1 cells)-bearing BALB/c mice demonstrated good dose dependent anti-tumor efficacy of CP-liposomes. A high tumor inhibition rate (TIR) of 82.2% was achieved with good tolerance. However, glycosylation modification failed to significantly enhance TIR of CP-liposomes. In summary, combined therapy with PPD proved to be a promising strategy for CBD to be developed into a novel antitumor drug, with characteristics of effectiveness, good tolerance, and the potential to overcome tumor cachexia.

Enhanced Solubility and Antitumor Activity of Annona Squamosa Seed Oil via Nanoparticles Stabilized with TPGS: Preparation and In Vitro and In Vivo Evaluation.

Annona squamosa seed oil (ASSO), which is a waste product in the extraction of annonaceous acetogenins (ACGs), displays good antitumor activity against a variety of tumor cells. However, ASSO is insoluble and has low bioavailability. In order to improve the solubility and application value of ASSO, the seed oil nanoparticles (ASSO-NPs) were successfully prepared only using TPGS as a stabilizer. ASSO-NPs obtained were spherical with a uniform size (less than 200 nm). ASSO-NPs showed the good storage stability at 25 ± 2 °C and were suitable for both oral administration and intravenous injection. The antitumor study in vitro and in vivo demonstrated more enhanced antitumor efficacy of ASSO-NPs than free ASSO. The ASSO-NPs group (15 mg/kg) had the highest tumor inhibition rate (TIR) of 69.8%, greater than the ASSO solution (52.7%, 135 mg/kg, p < 0.05) in 4T1 tumor-bearing mice. The in vivo biodistribution data displayed that the fluorescence intensity of ASSO/DiR-NPs in tumor was similar to that in liver in the presence of the reticuloendothelial system. Besides, the relative tumor-targeting index (RTTI) of (ACGs + ASSO)-NPs was 1.47-fold that of ACGs delivered alone, and there is great potential in ASSO-NPs as tumor-targeted delivery vehicles. In this study, ASSO-NPs were firstly prepared by a very simple method with fewer excipients, which improved the solubility and antitumor activity of the ASSO, displaying a good prospect in the in vivo delivery of natural bioactive compounds.

Enhanced tumor accumulation and therapeutic efficacy of liposomal drugs through over-threshold dosing.

BACKGROUND: Most intravenously administered drug-loaded nanoparticles are taken up by liver Kupffer cells, and only a small portion can accumulate at the tumor, resulting in an unsatisfactory therapeutic efficacy and side effects for chemotherapeutic agents. Tumor-targeted drug delivery proves to be the best way to solve this problem; however, the complex synthesis, or surface modification process, together with the astonishing high cost make its clinical translation nearly impossible. METHODS: Referring to Ouyang's work and over-threshold dosing theory in general, blank PEGylated liposomes (PEG-Lipo) were prepared and used as tumor delivery enhancers to determine whether they could significantly enhance the tumor accumulation and in vivo antitumor efficacy of co-injected liposomal ACGs (PEG-ACGs-Lipo), a naturally resourced chemotherapeutic. Here, the phospholipid dose was used as an indicator of the number of liposomes particles with similar particle sizes, and the liposomes was labelled with DiR, a near-red fluorescent probe, to trace their in vivo biodistribution. Two mouse models, 4T1-bearing and U87-bearing, were employed for in vivo examination. RESULTS: PEG-Lipo and PEG-ACGs-Lipo had similar diameters. At a low-threshold dose (12 mg/kg equivalent phospholipids), PEG-Lipo was mainly distributed in the liver rather than in the tumor, with the relative tumor targeting index (RTTI) being ~ 0.38 at 72 h after administration. When over-threshold was administered (50 mg/kg or 80 mg/kg of equivalent phospholipids), a much higher and quicker drug accumulation in tumors and a much lower drug accumulation in the liver were observed, with the RTTI increasing to ~ 0.9. The in vivo antitumor study in 4T1 tumor-bearing mice showed that, compared to PEG-ACGs-Lipo alone (2.25 mg/kg phospholipids), the co-injection of a large dose of blank PEG-Lipo (50 mg/kg of phospholipids) significantly reduced the tumor volume of the mice by 22.6% (P < 0.05) and enhanced the RTTI from 0.41 to 1.34. The intravenous injection of a low drug loading content (LDLC) of liposomal ACGs (the same dose of ACGs at 50 mg/kg of equivalent phospholipids) achieved a similar tumor inhibition rate (TIR) to that of co-injection. In the U87 MG tumor-bearing mouse model, co-injection of the enhancer also significantly promoted the TIR (83.32% vs. 66.80%, P < 0.05) and survival time of PEG-ACGs-Lipo. CONCLUSION: An over-threshold dosing strategy proved to be a simple and feasible way to enhance the tumor delivery and antitumor efficacy of nanomedicines and was benefited to benefit their clinical result, especially for liposomal drugs.

A Low Dose of Hydrous Icaritin Nano-Formulation with Remarkable Efficacy and Tumor Targeting in Cancer Therapy.

Background: The use of chemotherapeutic drugs is restricted in the tumor-therapy because of the severely toxic and side effects among most important factors. The active herbal extracts are always used as a high dose while in the tumortherapy to achieve good anti-tumor effects. Hydrous icaritin has a high activity while there are few existing dosage forms as a result of low solubility in water and poor bioavailability. Results: The prepared hydrous icaritin nanorods (DP-HICT NRs) using mPEG2000-DSPE as a stabilizer, presented a narrow distribution of particle size with of 217 nm and a properly high drug-loading content of approximately 65.3±1.5%. A low dose of hydrous icaritin nano-formulation shows remarkable efficacy in cancer therapy (tumor inhibition rate: 61.36±10.80%) compared with the same dose of Paclitaxel injection (tumor inhibition rate: 66.80±4.43%), which approved as medicaments. Not only that, DP-HICT NRs can escape the clearance of the immune system and enhance targeting ability to the tumor site with only one excipient and such a low dose. Conclusions: This kind of nanoparticles contain a low dose of HICT used mPEG2000-DSPE as a stabilizer, while can achieve good tumor targeting as some active targeting agents and an anti-tumor effect as the PTX injection. There are broad prospects in drug safety, anti-tumor efficacy and even prognosis.

Sensitive Tumor Cell Line for Annonaceous Acetogenins and High Therapeutic Efficacy at a Low Dose for Choriocarcinoma Therapy.

Annonaceous acetogenins (ACGs) have attracted much attention because of excellent antitumor activity. However, the lack of selectivity and the accompanying serious toxicity have eventually prevented ACGs from entering clinical application. To decrease the side effects of ACGs, the cytotoxicity of ACGs on 10 types of tumor cell lines was investigated by the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) test to identify one that was very sensitive to ACGs. Meanwhile, ACGs nanoparticles (ACGs-NPs) were prepared using poloxamer 188 (P188) as an excipient so as to solve the problem of poor solubility and the in vivo delivery of ACGs. ACG-NPs were 163.9±2.5 nm in diameter, negatively charged, and spherical with a high drug loading content (DLC) of 44.9±1.2%. MTS assays demonstrated that ACGs had strong cytotoxicity against JEG-3, HeLa, SiHa, MCF-7, A375, A2058, A875, U-118MG, LN- 229, and A431 cells, among which JEG-3 cell line was extremely sensitive to ACGs with a 50% inhibitory concentration (IC50) value of 0.26 ng/mL, a very encouraging discovery. ACGs-NPs demonstrated very good dose-dependent antitumor efficacy in a broad range of 45?1200 µg/kg on JEG-3 tumor-bearing mice. At a very low dose (1200 µg/kg), ACGs-NPs achieved a high tumor inhibition rate (TIR) of 77.6% through oral administration, displaying a significant advantage over paclitaxel (PTX) injections that are currently used as first-line anti-choriocarcinoma drugs. In the acute toxicity study, the half lethal dose (LD50) of ACGs-NPs was 135.5 mg/kg, which was over 100 times as of the effective antitumor dose, indicating good safety of ACGs-NPs. ACGs-NPs show promise as a new type of and potent anti-choriocarcinoma drug in the future.

Hydrous icaritin nanorods with excellent stability improves the in vitro and in vivo activity against breast cancer.

Due to their various biological activities that are beneficial to human health and antitumor effect, flavonoid compounds have attracted much attention in recent years. Hydrous icaritin (HICT) was such a flavonoid that can inhibit the growth of breast cancer and cancer stem cells. In order to overcome the insolubility problem, HICT was fabricated into nanorods (NRs) through anti-solvent precipitation in this paper using D-α tocopherol acid polyethylene glycol succinate and sodium oleate as a co-stabilizer meanwhile using the mixture of ethanol and acetone (1:2, v/v) as the organic solvent. The obtained HICT NRs showed an average particle size 222.0 nm with a small polydispersity index value of 0.124 and a high zeta potential of - 49.5 mV. HICT NRs could maintain similar particle size in various physiological medium and could be directly lyophilized without the addition of any cytoprotectants and then reconstituted into a colloidal system of similar size. The resultant HICT NRs had a high drug loading content of 55.6% and released HICT in a steady and constant pattern. MTT assay indicated NRs enhanced HICT's antitumor activity to ninefold against MCF-7 breast carcinoma cells. In vivo studies demonstrated oral administration free HICT had almost no tumor inhibitory effect while HICT NRs showed a tumor inhibition rate of 47.8%. When intravenously injected, HICT NRs displayed similar therapeutic efficacy to paclitaxel injections (70.4% vs. 74.5%, TIR). This may be partly due to the high accumulation of the injected HICT NRs in tumor ranking only second to that in the liver but much higher than in other organs. These results demonstrated that HICT NRs could be a promising antitumor agent for the treatment of breast cancer in clinic.

Preparation, characterization and systemic application of self-assembled hydroxyethyl starch nanoparticles-loaded flavonoid Morin for hyperuricemia therapy.

BACKGROUND: Morin, one of the most widely distributed flavonoids in plants, has been identified as a potent antihyperuricemic agent. Its poor water solubility and fast in vivo clearance, however, have limited its application in the treatment of hyperuricemia. In this study, a novel amphiphilic polymer (hydroxyethyl starch-deoxycholic acid [HES-DOCA]) was synthesized to overcome these limitations. METHODS: HES-DOCA conjugates with various substitution degrees were prepared by chemical grafting DOCA to HES through ester formation. The structures of the conjugates were confirmed by infrared spectroscopy and 1H-NMR. Physicochemical characterizations of HES-DOCA nanoparticles-loaded Morin (Morin/HES-DOCA-NPs) were studied using dynamic light scattering and transmission electron microscopy (TEM). In vitro release studies were performed to evaluate the release properties of Morin from the NPs. Subsequently, in vivo pharmacokinetic parameters of Morin/HES-DOCA-NPs were investigated in Wistar rats through intravenous administration (2 mg/kg, equivalent to Morin). Antihyperuricemic efficacy of the NPs was evaluated in a rat hyperuricemic model. RESULTS: The optimized HES-based amphiphilic polymer contained approximately 10 DOCA groups per 100 anhydroglucose units of HES, which can spontaneously self-assemble to form spherical NPs as demonstrated by TEM images. Morin/HES-DOCA-NPs were monodispersed (polydispersity index = 0.05) with a mean diameter of 197 nm and exhibited a zeta potential of -14 mV. The use of DOCA as the polymer's hydrophobic segment enabled high drug loading efficiency (15.6%). After systemic administration, Morin/HES-DOCA-NPs exhibited significantly longer half-life and higher systemic exposure (elimination half-life and area under the plasma concentration-time curve) compared with free drug Morin. In a rat hyperuricemic model, treatment with Morin/HES-DOCA-NPs demonstrated superior therapeutic efficacy over Morin in decreasing serum uric acid level, increasing the uricosuric action, as well as attenuating hyperuricemia-associated inflammation in kidney of rats. CONCLUSION: Collectively, these findings suggest that the novel HES-based NP formulation of Morin may have great potential for clinical treatment of hyperuricemia.