Paclitaxel Content Research Articles

Optimization of balloon coating process for paclitaxel coated balloons via micro-pipetting method

Drug coated balloons (DCBs) have proven to be a suitable alternative for the treatment of cardiovascular diseases. They allow for uniform delivery of an antiproliferative drug to the stenotic site without permanent implantation of the device in the patient’s body. There are, however, regulatory concerns regarding the lack of data associated with variable drug delivery to the target site, which can be related to the coating process. This study describes the process for an in-house micro-pipetting coating method that incorporates a laboratory-developed coating equation for determining optimal coating parameters. The coating solutions included a common drug of choice, paclitaxel, along with a hydrophilic excipient, such as iopromide. It was found that using a revolution rate of 240 rev/min, a flow rate of 25 µL/min and a translational speed of 0.033 cm/s resulted in visually uniform coatings. High performance liquid chromatography (HPLC) allowed for the determination of paclitaxel content on the balloon surface. Scanning electron microscopy (SEM) enabled analysis of coating thickness and texture at distal, middle, and proximal positions on the balloon; average thicknesses were determined to be 16.4 ± 5.8, 14.8 ± 1.4, and 18.1 ± 3.9 µm, respectively. These optimized coating conditions have been confirmed by in vitro drug release kinetics studies. Overall this study generated a simple and reproducible micro-pipetting coating method for the sustained release of drugs from the drug coated balloons.

Self-assembly of biotinylated poly(ethylene glycol)-poly(curcumin) for paclitaxel delivery

Paclitaxel (PTX), one of the most potent anticancer agents, has showed a remarkable activity against varieties of tumors. However, the bioavailability of PTX is quite low due to its poor aqueous solubility. Moreover, the emerging multidrug resistance (MDR) in cancer to PTX remains a major obstacle for successful chemotherapy. In order to address these problems, we developed self-assembly of biotinylated poly(ethylene glycol)-poly(curcumin) (Biotin-PEG-PCDA) for PTX delivery (termed as PTX-BPC NPs) with the application of mPEG2K-P(CL-co-LLA) as an emulsifier. The loading content and encapsulation efficiency of PTX were 13.2% and 92.0%, respectively. In vitro drug release study showed that PTX-BPC NPs could degrade rapidly and then release the PTX payload in a 10 mM glutathione (GSH) environment. Compared with free PTX, PTX-BPC NPs exhibited enhanced anticancer efficacy (IC50(MCF-7/ADR cells), 17.28 µg/mL vs. 1.15 µg/mL). In addition, these biotin-modified nanoparticles could also significantly reverse PTX resistance by suppressing the over-expression of P-gp, thus resulting in increased intracellular drug accumulation and reduced drug efflux in MCF-7/ADR cells, which showed a great anticancer effect.

Effect of paclitaxel content in the DHP107 oral formulation on oral bioavailability and antitumor activity

DHP107 is a novel lipid-based oral paclitaxel formulation for the treatment of various cancers. In the present study, to increase the treatment effect of DHP107, we aimed to improve this formulation. We optimized the paclitaxel content in DHP107 formulation, evaluated its antitumor activity, and compared its activity with that of the intravenous paclitaxel formulation, Taxol®, in various mouse cancer models. The oral bioavailability of paclitaxel increased dose-dependently up to 50 mg/kg. However, the paclitaxel absorption from the DHP107 formulations containing ≥1.5% (w/v) paclitaxel decreased with the increase in DHP107 dose as paclitaxel was crystallized when exposed to water. Therefore, the optimized DHP107 formulation containing 1% (w/v) paclitaxel was selected, and it exhibited similar antitumor activity as Taxol®. However, the DHP107 showed a better survival rate with low toxicity than that of Taxol®. The concentration of paclitaxel in the tumor tissues of mice in the DHP107 was also higher than that in Taxol®. The optimized DHP107 formulation might reduce the possible toxic effects of the formulation, with antitumor activities similar to those of intravenous paclitaxel Taxol®, by enhancing the distribution to tumor tissues. Furthermore, it might be beneficial to use DHP107 for patients with hypersensitivity reactions to intravenous Taxol®.

Comparative Transcriptome Analysis Revealed the Tissue-Specific Accumulations of Taxanes among Three Experimental Lines of Taxus yunnanensis

Taxus yunnanensis (Yew) is known for natural anticancer metabolite paclitaxel (Taxol) and its biosynthesis pathway in yew species still needs to be completely elucidated. In the current study, productions of paclitaxel and 10-DAB III from three different tissues (needle, branch, and root) of T. yunnanensis wild type (WT) and two new cultivars Zhongda-1 (Zd1) and Zhongda-2 (Zd2) were determined, and significant tissue differences in contents of the taxanes were observed among the three experimental lines. The much higher 10-DAB III and lower paclitaxel contents in needle of Zd2 when compared with that of Zd1 indicated the low conversion from 10-DAB III to paclitaxel in the needle of Zd2. In order to uncover the mechanisms of the tissue-specific biosynthesis of the taxanes, transcriptome analysis of cultivar Zd2 was conducted, and the previously reported transcriptome data of Zd1 and WT were used to perform a comparison. The enhancement of TDAT and T10βH side biosynthetic pathway in roots of Zd2 in early taxane synthesis might lead to the biosynthesis of other toxoids, while the preference of T13αH route in the needle and branch of Zd2 was mainly responsible for the tissue-specific reinforced biosynthesis of 10-DAB III and paclitaxel in Zd2. Different from Zd1, the tissue-specific pattern of paclitaxel biosynthesis genes in Zd2 was similar to WT. However, the lower transcript abundance of final steps genes (TBT, DBAT, BAPT, and DBTNBT) of the paclitaxel biosynthesis pathway in Zd2 than in Zd1 might further promote 10-DAB III accumulation in Zd2.

Dual-Layer Coated Drug-Eluting Stents with Improved Degradation Morphology and Controlled Drug Release

Drug-eluting stents (DESs) are used to treat cardiovascular diseases such as atherosclerosis. The anti-proliferative drug released from the DES suppress the proliferation of smooth muscle cells and reduced in-stent restenosis. However, a burst release of the drug in the early stages and degradation morphology of the polymer coating represent major disadvantages, which might increase the incidence of in-stent restenosis and/or thrombosis under in vivo clinical studies. To solve these problems, in this study, a double-layer coating system composed of poly(lactide) (PLLA) bottom layer and poly(lactide-co-glycolide) (PLGA) top layer are used for the fabrication of DES. PLLA bottom layer was firstly coated on the metal surface followed by oxygen ion beam treatment. It was found that increasing the ion beam exposure time, increased the roughness of PLLA surface with a nanoscale pocket (or hole)-like structure. The top layer coating represented a mixture of PLGA and paclitaxel (PTX) with 5, 10, and 20% PTX contents. The coating was performed through ultrasonic spray technique, and the morphology showed not only a smooth and uniform surface but also no irregularities were observed at zero day. The drug release and degradation morphology for single-layer (PLGA/PTX) and double-layer (PLLA/PLGA/PTX) coatings were compared. The drug release from the double-layer stainless steel (SS) group showed a slower and controlled drug release for all PTX content samples as compared to single-layer SS group. Moreover, the degradation morphology of double-layer SS group presented a smoother and uniform surface after 12 weeks of degradation under physiological conditions. Therefore, an oxygen ion beam technique with double-layer coating system could effectively control the drug release, i.e., prevent initial burst drug release, and improve the degradation morphology of biodegradable polymer-based DESs.

Freeze-dried diethylenetriaminepentaacetic acid-functionalized polymeric micelles containing paclitaxel: A kit formulation for theranostic application in cancer

Polymeric micelles (PM) are versatile nanoparticles with suitable properties to tumor delivery of hydrophobic drugs such as paclitaxel (PTX) and imaging probes such as technetium-99 m. However, instability of drug content in aqueous medium and obstacles related to lengthy radiolabeling procedures, high radiation exposure and risk of human error limit its clinical application. Freeze-dried kit formulation might be a strategy to overcome these issues. Thus, we developed a freeze-dried kit formulation containing diethylenetriaminepentaacetic acid (DTPA)-functionalized 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethyleneglycol)-2000] polymeric micelles carrying PTX (PM-DTPA/PTX) for application in the diagnosis and/or treatment of solid tumors. PM-DTPA/PTX were prepared and the physical and radiochemical characteristics (size, zeta potential, PTX content and radiolabeling yields) evaluated before lyophilization process and after storage up to 180 days. In vivo biodistribution studies were performed in 4T1 breast tumor-bearing BALB/c mice. A freeze-dried kit containing PM-DTPA/PTX showed high storage stability in all parameters evaluate up to 180 days since no significant alteration was observed at all evaluated timeframes. The freeze-drying process did not change the physicochemical and biological properties of the PM, including the property of tumor targeting. Therefore, a stable freeze-dried kit containing PM-DTPA/PTX was developed as an easy and fast preparation and showed high potential for theranostic application in cancer treatment.

Paclitaxel controlled delivery using a pH-responsive functional-AuNP/block-copolymer vesicular nanocarrier composite system

Paclitaxel (PTX)-loaded gold nanoparticles functionalized with mercaptooctanoic acid (MOA) and folic acid (FA) (AuMOA-FA) were encapsulated within pH-sensitive poly(2-vinylpyridine)-b-poly(ethylene oxide) (P2VP-PEO) vesicles with the aim to develop a more selective injectable nano-formulation for PTX, lacking the side effects of the conventional PTX delivery system. The size of the resulting composite vesicles was lower than 200 nm, i.e. it is suitable for tumor targeting applications taking advantage of the enhanced permeability and retention (EPR) effect. The vesicles did not aggregate in the presence of high electrolyte concentrations, indicating the colloidal stability of the vesicles. The vesicles did not leak their AuMOA-FA or PTX content at physiological pH of 7.4. However, AuMOA-FA and PTX release were significantly accelerated at acidic pHs resembling tumor environment and acidic intracellular compartments. PTX release from the vesicles at acidic pH apparently follows AuMOA-FA release from the vesicles. Flow cytometry measurements and confocal laser scanning microscopy images showed that the vesicles could enter A549 cancer cells in culture and that cellular uptake increased with time. Blank vesicles did not exhibit cytotoxicity and did not induce apoptosis in A549 cancer cells. The PTX currying vesicles exhibited comparable or a little higher cytotoxicity than free PTX. Both the PTX currying vesicles and free PTX induced A549 cells apoptosis, however the vesicle-encapsulated PTX induced a higher percentage of late apoptotic cells than free PTX.

Spatial Distribution and Growth Period of Effective Components in Leaves of Taxus cuspidata

Taxus cuspidata Sieb. ET. Zucc. is a taxus of Taxaceae, a rare third-order relict species distributed in northeastern China, and a wild endangered plant species protected by national level I. Taxol (paclitaxel, trade name taxol) and cephalomannine (cephalomannine) are all diterpenoids contained in the genus Taxus, with broad-spectrum anti-tumor activity and unique anti-cancer mechanism. In this study, the distribution of paclitaxel and cephalomannine in the leaves of Taxus cuspidata in different parts and different growth stages was discussed. The results showed that the content of two substances in the leaves of the majority of the crowns was lower than that of the biennial and tertiary there were no significant differences in the contents of two substances in the two-year and three-year-old foliage. There was no significant difference in the contents of the two layers in the three levels of the noodles, and the content of the male was slightly higher than that of the dark. The content of paclitaxel in the leaves of natural northeast yew was the highest at dormancy period, and the content of flowering and fruit was not much different. The content of Cephalotaxin was the highest in dormancy period, and that of cephalosporin the content of paclitaxel and cephalomannine in each plant were significantly different. There was significant difference between the two plants.

Transcriptome profiling reveals specific patterns of paclitaxel synthesis in a new Taxus yunnanensis cultivar

The difference in contents of paclitaxel and 10-deacetylbaccatin III (10-DABIII) in needles between wildtype (WT) and a new cultivar (Zhongdayihao, ZD1) of Taxus yunnanensis was examined. Transcriptome profiling was conducted for different tissues of the ZD1 and WT to illustrate the regulation mechanism of paclitaxel biosynthesis. It was observed that average contents of paclitaxel and 10-DABIII in ZD1 were 4 folds and 32 folds higher than those in WT, respectively. More significant elevations of differential expressed genes (DEGs) from paclitaxel biosynthesis pathway were revealed in ZD1 rather than WT, which should be responsible for the higher contents of paclitaxel and 10-DABIII in the ZD1. Special tissues-dependent expression patterns of paclitaxel biosynthesis DEGs in ZD1 compared to WT were unraveled. The relative higher expressions of paclitaxel biosynthesis genes in needles than other tissues supported the higher content of paclitaxel and 10-DABIII content in needles of ZD1. Attenuation of plant hormone signal transduction pathway led to the lower expression of TFs in ZD1 rather than WT. Besides, the significant negative correlations between differential expressed TFs and DEGs from paclitaxel biosynthesis pathway displayed a possibly negative regulation pattern of these TFs on paclitaxel biosynthesis pathway genes. These results provided new insights into the molecular process of paclitaxel synthesis in Taxus.

Enhancement of paclitaxel content in induced tetraploid Corylus avellana L. cell suspension culture with regulating the expression of genes in paclitaxel biosynthetic pathway

During recent years, hazel cell suspension culture has been significantly considered as a new important source of paclitaxel. Artificial polyploidy alters different characters in plants which results in amplifying the secondary metabolites in medicinal plants. In this paper, the effects of tetraploidy induction on paclitaxel content and gene expression in hazel cell suspension culture were investigated. Various concentrations of colchicine and duration of exposure in solid and liquid media were examined and the ploidy level of cells was determined using flow cytometric analysis. The tetraploid cells were obtained from 0.2% colchicine in the exposure time of 5 and 6 days in solid medium and 0.3% colchicine in the exposure time of 3 and 4 days in liquid medium. Tetraploid cells were employed to prepare cell suspension. 3 µM of phenylalanine and 0.05 mM of vanadyl sulfate were added to both tetraploid and diploid (control) suspension to elicit paclitaxel induction. High performance liquid chromatography analysis demonstrated that the tetraploid cell suspensions produced paclitaxel of about [9.88 µg g−1 (DW)] 1.7-fold compared with diploid cells [5.74 µg g−1 (DW)]. The application of phenylalanine and vanadyl sulfate increased the concentration of paclitaxel in both diploid and tetraploid cells. Moreover, qRT-PCR analysis showed that the expression of GGPPS gene was significantly increased and PAL gene expression was altered after tetraploidization.

Targeting ROS-rich cancer cells with thermo/oxidation-responsive polymeric nanoaggregates: synthesis, morphological and in vitro studies

Paclitaxel (PTX)-loaded gold nanoparticles functionalized with mercaptooctanoic acid (MOA) and folic acid (FA) (AuMOA-FA) were encapsulated within pH-sensitive poly(2-vinylpyridine)-b-poly(ethylene oxide) (P2VP-PEO) vesicles with the aim to develop a more selective injectable nano-formulation for PTX, lacking the side effects of the conventional PTX delivery system. The size of the resulting composite vesicles was lower than 200 nm, i.e. it is suitable for tumor targeting applications taking advantage of the enhanced permeability and retention (EPR) effect. The vesicles did not aggregate in the presence of high electrolyte concentrations, indicating the colloidal stability of the vesicles. The vesicles did not leak their AuMOA-FA or PTX content at physiological pH of 7.4. However, AuMOA-FA and PTX release were significantly accelerated at acidic pHs resembling tumor environment and acidic intracellular compartments. PTX release from the vesicles at acidic pH apparently follows AuMOA-FA release from the vesicles. Flow cytometry measurements and confocal laser scanning microscopy images showed that the vesicles could enter A549 cancer cells in culture and that cellular uptake increased with time. Blank vesicles did not exhibit cytotoxicity and did not induce apoptosis in A549 cancer cells. The PTX currying vesicles exhibited comparable or a little higher cytotoxicity than free PTX. Both the PTX currying vesicles and free PTX induced A549 cells apoptosis, however the vesicle-encapsulated PTX induced a higher percentage of late apoptotic cells than free PTX.

An endophytic fungus efficiently producing paclitaxel isolated from Taxus wallichiana var. mairei.

Paclitaxel is a medicinal ingredient with high anticancer activity and widely used in hospitals and clinics. In this study, we isolate endophytic fungi efficiently producing paclitaxel from yew for the purpose of paclitaxel manufacture.The bark of Taxus wallichiana var. mairei was surface sterilized and then inoculated in potato dextrose agar culture medium to isolate endophytic fungi. The paclitaxel in the fungal culture was extracted with mixture of chloroform and the same amount of methanol. The content of paclitaxel in the extract was determined and identified with LC-MS. The endophytic fungus efficiently producing paclitaxel was species identified with ITS rDNA and 26S D1/D2 rDNA sequencing.There were 528 endophytic fungal strains were isolated from the bark of T wallichiana var. mairei in total. There was only a strain efficiently producing paclitaxel in these endophytic fungi. The unique strain was identified as Phoma medicaginis. The paclitaxel contents in whole potato dextrose broth (PDB) culture, spent culture medium from this strain and that in dry mycelium is 1.215 mg/L, 0.936 mg/L, and 20 mg/kg, respectively.An endophytic fungus efficiently producing paclitaxel was isolated from T wallichiana var. mairei. This isolated endophytic fungus can be used as a producing strain for paclitaxel manufacture.

Preparation and in vitro evaluation of an acidic environment-responsive liposome for paclitaxel tumor targeting

Paclitaxel (PTX) is an important cancer chemotherapeutic drug. To ameliorate the disadvantages of paclitaxel, this study designed liposomes to load paclitaxel, adding the acid-sensitive material cholesteryl hemisuccinate (CHEMS) to increase the accumulation of the drug in the tumor site. To begin, we used a high-performance liquid chromatography (HPLC) method to determine the content of PTX and the encapsulation efficiency. Then, we prepared paclitaxel-loaded acid-sensitive liposomes (PTX ASLs) by a thin-film dispersion method. We investigated the physical and chemical properties of the liposomes. The particle size was 210.8 nm, the polydispersity index (PDI) was 0.182 and the ζ-potential was −31.2 mV. The liposome shape was observed by transmission electron microscopy (TEM), and the results showed that the liposomes were round with a homogenous size distribution. The release characteristics of the liposomes in vitro were studied via a dynamic dialysis method. The results showed that the prepared liposomes had acid sensitivity and sustained release properties. An in vitro cellular uptake assay of MCF-7 cells showed that the cell uptake of coumarin-6-loaded acid-sensitive liposomes was significantly higher than that of free coumarin-6. The cytotoxicity of the PTX ASLs was significantly higher than that of paclitaxel. In conclusion, these results showed that the prepared liposomes had clear acid-sensitive release characteristics and a higher cell uptake rate and cytotoxicity than free PTX. The system is very suitable for targeted cancer therapy with paclitaxel.

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.

Paclitaxel dimers assembling nanomedicines for treatment of cervix carcinoma

Poor water solubility and adverse side effects pose a challenge for clinical application of paclitaxel (PTX). In this work, a series of PTX dimers are synthesized by coupling two PTX molecules with dicarboxylic acids. As-synthesized PTX dimers form stable nanoparticles in aqueous solution without using any surfactants or adjuvants, and the solubility of PTX in water increases by 2500-fold compared to that of free PTX. These nanoparticles with high content of PTX are internalized by cancer cells and exhibit comparable cytotoxicity with Taxol. Furthermore, when the PTX dimers are incorporated into methoxypoly(ethylene glycol)2K–block-poly(d, l-lactide)2K (PEG-PDLLA) micelles, the loading content of PTX dimers is as high as 85wt%. The formed nanoparticles possess the high stability in biological conditions. Both in vitro and in vivo experiments show that these (PTX dimer)/PEG-PDLLA formulations possess effective cellular uptake and potent cytotoxicity, and exhibit reduced systemic toxicity and enhanced antitumor efficacy towards human cervical tumor. We believe these PTX dimers-based nanoparticles would be an alternative formulation for PTX, and such drug dimer assembling behaviors could be extended to other therapeutic agents.

Improved Antitumor Efficacy of Hyaluronic Acid-Complexed Paclitaxel Nanoemulsions in Treating Non-Small Cell Lung Cancer.

Paclitaxel (PTX) is a effectively chemotherapeutic agent which is extensively able to treat the non-small cell lung, pancreatic, breast and other cancers. But it is a practically insoluble drug with water solubility less than 1 μg/mL, which restricts its therapeutic application. To overcome the problem, hyaluronic acid-complexed paclitaxel nanoemulsions (HPNs) were prepared by ionic complexation of paclitaxel (PTX) nanoemulsions and hyaluronic acid (HA) to specifically target non-small cell lung cancer. HPNs were composed of dl-α-tocopheryl acetate, soybean oil, polysorbate 80, ferric chloride, and HA and fabricated by high-pressure homogenization. The HPNs were 85.2 ± 7.55 nm in diameter and had a zeta potential of −35.7 ± 0.25 mV. The encapsulation efficiency was almost 100%, and the PTX content was 3.0 mg/mL. We assessed the in vivo antitumor efficacy of the HPNs by measuring changes in tumor volume and body weight in nude mice transplanted with CD44-overexpressing NCI-H460 xenografts and treated with a bolus dose of saline, Taxol®, PTX nanoemulsions (PNs), or HPNs at a dose of 25 mg/kg. Suppression of cancer cell growth was higher in the PN- and HPN-treated groups than in the Taxol® group. In particular, HPN treatment dramatically inhibited tumor growth, likely because of the specific tumor-targeting affinity of HA for CD44-overexpressed cancer cells. The loss of body weight and organ weight did not vary significantly between the groups. It is suggest that HPNs should be used to effective nanocarrier system for targeting delivery of non-small cell lung cancer overexpressing CD44 and high solubilization of poorly soluble drug.

Enzyme-Sensitive and Amphiphilic PEGylated Dendrimer-Paclitaxel Prodrug-Based Nanoparticles for Enhanced Stability and Anticancer Efficacy.

In this study, we prepared a smart polymeric vehicle for the hydrophobic drug paclitaxel (PTX) that allowed a maximum steady-state circulation and a fast intracellular release in tumors. PTX was linked to the Janus PEGylated (PEG = poly(ethylene glycol)) peptide dendrimer via an enzyme-sensitive linker glycylphenylalanylleucylglycine tetrapeptide by efficient click reaction, resulting in Janus dendritic prodrug with 20.9% PTX content. The prodrug self-assembled into nanoscale particles with appropriate nanosizes, compact morphology, and negative surface charge. In addition to high stability during circulation, as demonstrated by protein adsorption assays and drug release studies in the cancer's intracellular environment, the nanoparticles were able to quickly release the drug intact in its original molecular structure, as verified via high-performance liquid chromatography and mass spectrometry analyses. Compared to free PTX, the enzyme-responsive feature of nanoparticles promoted higher cytotoxicity against 4T1 cancer cells and much lower cytotoxicity against normal cells. The nanoparticles accumulated in the tumor and were retained for an extended period of time, as confirmed by fluorescence imaging. Therefore, these nanoparticles exhibited significantly enhanced antitumor efficiency in the 4T1 breast cancer model as indicated by the observed inhibition of angiogenesis and proliferation as well as induction of apoptosis. Moreover, the nanoparticles reduced the occurrence of side effects, particularly dose-limited toxicities, as monitored by body weight and hematological features. Hence, our Janus PEGylated dendrimer-PTX prodrug-based nanoparticles may potentially serve as nanoscale vehicles for breast cancer therapy.

Drug release kinetics from a drug-eluting stent with asymmetrical coat.

The aim of this study was to investigate the drug release profiles of biodegradable polymer sirolimus- or paclitaxel-eluting stents with asymmetrical coating (BPSES-A or BPPES-A) both in vitro and in vivo. In vitro, the drug release profile was characterized by measuring the drug concentration by HPLC over a time-course. In vivo, a porcine aorta stenting model was employed. The results showed that the drug release rates of BPSES-A and BPPES-A were slower, more stable and less burst releasing than those of conventionally coated stents (BPSES-C and BPPES-C respectively), both in vitro and in vivo. Based on the in vivo results, the sirolimus and paclitaxel content of the local coronary wall was maintained at a higher and more effective level with BPSES-A and BPPES-A than with BPSES-C and BPPES-C, respectively. The drug levels in peripheral tissue samples were below detection levels. These data demonstrated the effectiveness of both sirolimus and paclitaxel as stent coating agents, and revealed the favorable drug release kinetics and pharmacokinetics of asymmetrical coated stents compared with conventional coated stents.

Seasonal Dynamics of Metabolites in Needles of Taxus wallichiana var. mairei.

Seasonal variations of the phytochemicals contents in needles of T. wallichiana var. mairei due to the effects of growth meteorological parameters were investigated in this study. The needles of T. wallichiana var. mairei were collected from different months and the contents of taxoids (paclitaxel, 10-deacetylbaccatin III (10-DAB), baccatin III, cephalomannine, 10-deacetyltaxol (10-DAT)), flavones (ginkgetin, amentoflavone, quercetin) and polysaccharides were quantified by ultra performance liquid chromatography (UPLC) and the resonance light scattering (RIL) method. The content of taxoids gave the highest level of 1.77 ± 0.38 mg·g−1 in January, and the lowest value of 0.61 ± 0.08 mg·g−1 in September. Unlike taxoids, the content of flavonoids was the highest in August. The content of polysaccharides reached peak value of 28.52 ± 0.57 mg·g−1 in September, which was two times higher than the lowest content of 9.39 ± 0.17 mg·g−1 in January. The contents of paclitaxel, 10-DAB, 10-DAT and polysaccharides significantly depended on meteorological parameters. The mean of minimum temperature (R = −0.61) and length of daylight (R = −0.60) were significantly correlated to 10-DAB content, while 10-DAT level showed significant correlation with length of daylight (R = −0.70) and relative humidity (R = 0.70). In addition, temperature had significantly negative effect on the content of paclitaxel and a significantly positive effect on that of polysaccharides. This study enriched the knowledge on the accumulation pattern of metabolites and could help us to determine the collecting time of T. wallichiana var. mairei for medicinal use.

Synergistic Chemo-Photothermal Therapy of Breast Cancer by Mesenchymal Stem Cell-Encapsulated Yolk-Shell GNR@HPMO-PTX Nanospheres.

Mesenchymal stem cells (MSCs) have attracted increasing attention as vehicles for cancer treatment. Herein, MSC-based synergistic oncotherapy strategy is presented for the first time. To achieve this goal, yolk-shell structured gold nanorod embedded hollow periodic mesoporous organosilica nanospheres (GNR@HPMOs) with high paclitaxel (PTX) loading capability and excellent photothermal transfer ability upon near-infrared (NIR) light irradiation are first prepared. Cytotoxicity and migration assays show that the viability and tumor-homing capability of MSCs are well-retained after internalization of high content of PTX loaded GNR@HPMOs (denoted as GNR@HPMOs-PTX). In vitro experiments show the GNR@HPMOs-PTX loaded MSCs (GNR@HPMOs-PTX@MSCs) possess synergistic chemo-photothermal killing effects for breast cancer cells. Also, photoacoustic imaging shows that the MSCs can improve dispersion and distribution in tumor tissue for GNR@HPMOs-PTX after intratumoral injection. In vivo experiments in breast cancer model of nude mice further demonstrate that the GNR@HPMOs-PTX@MSCs significantly inhibit tumor growth, suggesting their great potential for synergistic therapy of cancer.