Synthesis and characterization of PEG-PCL-PEG thermosensitive hydrogel.

In this work, a series of biodegradable triblock poly(ethylene glycol)-poly(epsilon-caprolactone)-poly(ethylene glycol) (PEG-PCL-PEG, PECE) copolymers were successfully synthesized by ring-opening copolymerization, and were characterized by (1)H NMR, FT-IR, GPC, and DSC. Aqueous solutions of PECE copolymers underwent thermosensitive sol-gel-sol transition as temperature increases when the concentration was above corresponding critical gel concentration (CGC). Sol-gel-sol phase transition diagrams were recorded using test tube inverting method, which depended on hydrophilic/hydrophobic balance in macromolecular structure, as well as some other factors, including topology of triblock copolymers and solution composition of the hydrogel. As a result, the sol-gel-sol transition temperature range could be varied, which might be very useful for its application as injectable drug delivery systems. The in vivo gel formation and degradation behavior was conducted by injecting aqueous PECE solution into KunMing mice subcutaneously. In vitro degradation behavior, in vitro drug release behavior, and cytotoxicity were also investigated in this paper. Therefore, owing to great thermosensitivity and biodegradability of these copolymers, PECE hydrogel is believed to be promising for in situ gel-forming controlled drug delivery system.

A novel injectable local hydrophobic drug delivery system: Biodegradable nanoparticles in thermo-sensitive hydrogel.

In this article, a novel local hydrophobic drug delivery system: nanoparticles in thermo-sensitive hydrogel, was demonstrated. First, honokiol, as a model hydrophobic drug, loaded poly(epsilon-caprolactone)-poly(ethylene glycol)-poly(epsilon-caprolactone) (PCEC) nanoparticles were prepared by emulsion solvent evaporation method, and then were incorporated into thermo-sensitive F127 hydrous matrix. The obtained injectable hydrophobic drug delivery system can act as a depot for sustained release of honokiol in situ. The lower critical solution temperature (LCST) of the composite matrix increases with increase in the mass of incorporated nanoparticles, or with decrease in the amount of residual organic solvent in the system. Honokiol release profile in vitro was studied, and the results showed that honokiol could be sustained released from the system. The described injectable drug delivery system might have great potential application for local delivery of hydrophobic drugs such as honokiol.

Synergistic antitumor effects of liposomal honokiol combined with adriamycin in breast cancer models.

Honokiol, a novel antitumor agent, could induce apoptosis and inhibit the growth of vascular endothelium in several tumor cell lines and xenograft models. It has been suggested that the antitumor effect of chemotherapy could be increased by combining it with an antiangiogenesis agent in anticancer strategy. The present study explored the potential to increase the antitumor effect of adriamycin by combining it with honokiol in mouse 4T1 breast cancer models, and the underlining mechanism was investigated. Honokiol was encapsulated in liposomes to improve the water insolubility. In vitro, liposomal honokiol inhibited the proliferation of 4T1 cells via apoptosis and significantly enhanced the apoptosis of 4T1 cells induced by adriamycin. In vivo, the systemic administration of liposomal honokiol and adriamycin significantly decreased tumor growth through increased tumor cell apoptosis compared with either treatment alone. Collectively, these findings suggest that liposomal honokiol may augment the induction of apoptosis in 4T1 cells in vitro and in vivo, and this combined treatment has shown synergistic suppression in tumor progression according to the analysis of isobologram. The present study may be important in future exploration of the potential application of the combined approach in the treatment of breast cancer.

Evaluation of toxicity and single-dose pharmacokinetics of intravenous ursolic acid liposomes in healthy adult volunteers and patients with advanced solid tumors.

OBJECTIVE: The purpose of this study was to investigate the maximum tolerated dose (MTD), dose-limiting toxicity (DLT), and pharmacokinetics of ursolic acid liposomes (UAL), as a new drug, in healthy adult volunteers and patients with advanced solid tumors. METHODS: All subjects received a single-dose of UAL (11, 22, 37, 56, 74, 98, and 130 mg/m(2)) administered as a 4-h intravenous infusion. Toxicity was assessed and plasma samples were analyzed using validated ultra-performance liquid chromatograph/tandem mass spectroscopy method. RESULTS: A total of 63 subjects including 4 patients and 35 healthy adult volunteers for toxicity study and 24 healthy adult volunteers for pharmacokinetic study were enrolled in this trial. The DLT was encountered at 74, 98, and 130 mg/m(2), and consisted of hepatotoxicity and diarrhea. Other adverse events included grade 1 nausea, grade 2 abdominal distention, grade 1 microscopic hematuria, grade 2 elevated serum sodium, grade 1 vascular stimulation, and grade 1 skin rash. The MTD was 98 mg/m(2). The single-dose pharmacokinetic parameters revealed a linear relationship between C(max), AUC(0→24 h), or AUC(0→∞) and escalated doses. CONCLUSIONS: The clinical data reported for the first time that UAL had manageable toxicities with MTD of 98 mg/m(2). The DLT were hepatotoxicity and diarrhea. Meanwhile, UAL had a linear pharmacokinetic profile. The registration number of this trial is ChiCTR-ONC-12002385.

In situ injectable nano-composite hydrogel composed of curcumin, N,O-carboxymethyl chitosan and oxidized alginate for wound healing application.

In this paper, an in situ injectable nano-composite hydrogel composed of curcumin, N,O-carboxymethyl chitosan and oxidized alginate as a novel wound dressing was successfully developed for the dermal wound repair application. Nano-curcumin with improved stability and similar antioxidant efficiency compared with that of unmodified curcumin was developed by using methoxy poly(ethylene glycol)-b-poly(ε-caprolactone) copolymer (MPEG-PCL) as carrier followed by incorporating into the N,O-carboxymethyl chitosan/oxidized alginate hydrogel (CCS-OA hydrogel). In vitro release study revealed that the encapsulated nano-curcumin was slowly released from CCS-OA hydrogel with the diffusion-controllable manner at initial phase followed by the corrosion manner of hydrogel at terminal phase. In vivo wound healing study was performed by injecting hydrogels on rat dorsal wounds. Histological study revealed that application of nano-curcumin/CCS-OA hydrogel could significantly enhance the re-epithelialization of epidermis and collagen deposition in the wound tissue. DNA, protein and hydroxyproline content in wound tissue from each group were measured on 7th day of post wounding and the results also indicated that combined using nano-curcumin and CCS-OA hydrogel could significantly accelerate the process of wound healing. Therefore, all these results suggested that the developed nano-curcumin/CCS-OA hydrogel as a promising wound dressing might have potential application in the wound healing.

Paclitaxel loaded folic acid targeted nanoparticles of mixed lipid-shell and polymer-core: in vitro and in vivo evaluation.

A functional drug carrier comprised of folic acid modified lipid-shell and polymer-core nanoparticles (FLPNPs) including poly(D,L-lactide-co-glycolide) (PLGA) core, PEGylated octadecyl-quaternized lysine modified chitosan (PEG-OQLCS) as lipid-shell, folic acid as targeting ligand and cholesterol was prepared and evaluated for targeted delivery of paclitaxel (PTX). Confocal microscopy analysis confirmed the coating of the lipid-shell on the polymer-core. Physicochemical characterizations of FLPNPs, such as particle size, zeta potential, morphology, encapsulation efficiency, and in vitro PTX release, were also evaluated. The internalization efficiency and targeting ability of FLPNPs were demonstrated by flow cytometry and confocal microscopy. PTX loaded FLPNPs showed a significantly higher cytotoxicity than the commercial PTX formulation (Taxol®). The intravenous administration of PTX encapsulated FLPNPs led to tumor regression and improvement of animal survival in a murine model, compared with that observed with Taxol® and biodistribution study showed that PTX concentration in tumor for PTX encapsulated FLPNPs was higher than other PTX formulations. Our data indicate that PTX loaded FLPNPs are a promising nano-sized drug formulation for cancer therapy.

Peptide ligand and PEG-mediated long-circulating liposome targeted to FGFR overexpressing tumor in vivo.

BACKGROUND AND METHODS: Paclitaxel, a widely used antitumor agent, has limited clinical application due to its hydrophobicity and systemic toxicity. To achieve sustained and targeted delivery of paclitaxel to tumor sites, liposomes composed of egg phosphatidylcholine, cholesterol, and distearolyphosphatidyl ethanolamine-N-poly(ethylene glycol) (PEG(2000)) were prepared by a lipid film method. In addition, the liposomes also contained truncated fibroblast growth factor fragment-PEG-cholesterol as a ligand targeting the tumor marker fibroblast growth factor receptor. Physicochemical characteristics, such as particle size, zeta potential, entrapment efficiency, and release profiles were investigated. Pharmacokinetics and biodistribution were evaluated in C57BL/6 J mice bearing B16 melanoma after intravenous injection of paclitaxel formulated in Cremophor EL (free paclitaxel), conventional liposomes (CL-PTX), or in targeted PEGylated liposomes (TL-PTX). RESULTS: Compared with CL-PTX and free paclitaxel, TL-PTX prolonged the half-life of paclitaxel by 2.01-fold and 3.40-fold, respectively, in plasma and improved the AUC(0→t) values of paclitaxel by 1.56-fold and 2.31-fold, respectively, in blood. Biodistribution studies showed high accumulation of TL-PTX in tumor tissue and organs containing the mononuclear phagocyte system (liver and spleen), but a considerable decrease in other organs (heart, lung, and kidney) compared with CL-PTX and free paclitaxel. CONCLUSION: The truncated fibroblast growth factor fragment-conjugated PEGylated liposome has promising potential as a long-circulating and tumor-targeting carrier system.

Preparation, characterization, pharmacokinetics, and bioactivity of honokiol-in-hydroxypropyl-ß-cyclodextrin-in-liposome.

Entrapping inclusion complexes in liposomes has been proposed to increase the entrapment efficiency (EE) and stability of liposomes compared with conventional liposomes. In the present study, a stable honokiol-in-hydroxypropyl-ß-cyclodextrin-in-liposome (honokiol-in-HP-ß-CD-in-liposome) was developed as honokiol delivery system by a novel method. The final molar ratio of honokiol/HP-ß-CD/lipid was selected as 1:2:2. The mean particle size was 123.5 nm, the zeta potential was -25.6 mV, and the EE was 91.09 ± 2.76%. The release profile in vitro demonstrated that honokiol is released from honokiol-in-HP-ß-CD-in-liposome with a sustained and slow speed. Crystallographic study indicated that honokiol was first bound within HP-ß-CD and then the inclusion complex was encapsulated within liposomes. Honokiol-in-HP-ß-CD-in-liposome without freeze dry kept stable for at least 6 months at 4°C. Pharmacokinetic study revealed that honokiol-in-HP-ß-CD-in-liposome significantly retarded the elimination and prolonged the residence time in circulating system. The data of bioactivity showed that honokiol-in-HP-ß-CD-in-liposome remained similar antiproliferative activity in A549 and HepG2 tumor cells compared to free honokiol. These results suggested that we had successfully prepared honokiol-in-HP-ß-CD-in-liposome. The novel honokiol formulation was easy to push industrialization forward and might be a potential carrier for honokiol delivery in tumor chemotherapy.

Truncated bFGF-mediated cationic liposomal paclitaxel for tumor-targeted drug delivery: improved pharmacokinetics and biodistribution in tumor-bearing mice.

Fibroblast growth factor receptors, overexpressed on the surface of a variety of tumor cells and on tumor neovasculature, are potential targets for tumor- and vascular-targeting therapy. The purpose of our present study was to compare the pharmacokinetics and tissue distribution of a novel truncated basic fibroblast growth factor peptide-mediated cationic liposomal paclitaxel (tbFGF-LPs-PTX) with free paclitaxel (F-PTX) and cationic liposomal paclitaxel (LPs-PTX) in tumor-bearing mice. In plasma, tbFGF-LPs-PTX exhibited similar pharmacokinetic properties to LPs-PTX but different with F-PTX. The AUC(0→∞) values were about 1.38-fold and one fold compared with those of F-PTX and LPs-PTX, respectively. TbFGF-LPs-PTX showed significant difference in biodistribution characteristics and displayed high accumulation in tumor and spleen in comparison with other two formulations. The AUC(0→∞) values achieved, respectively, about 7.17-fold and 2.60-fold accumulation in tumor, and about 4.28-fold and 2.25-fold increase in spleen compared with those of F-PTX and LPs-PTX. In contrast, the AUC(0→∞) values were much lower in liver compared with those of F-PTX and LPs-PTX. Our data indicated that tbFGF-LPs-PTX significantly increased the accumulation in tumor and prolonged the retention time, suggesting that it was a promise tumor-targeted delivery system and might provide a new treatment strategy for tumors.

Improved solubility and pharmacokinetics of PEGylated liposomal honokiol and human plasma protein binding ability of honokiol.

PEGylated liposomal honokiol had been developed with the purpose of improving the solubility and pharmacokinetics compared with free honokiol. Human plasma protein binding ability of honokiol was also investigated. PEGylated liposomal honokiol was prepared by thin film evaporation-sonication method. Its mean particle size was 98.68 nm, mean zeta potential was -20.6 mV and encapsulation efficiency were 87.68±1.56%. The pharmacokinetics of PEGylated liposomal honokiol was studied after intravenous administration in Balb/c mice. There were significant differences of parameters T(1/2ß) and AUC(0→∞) between them and liposome lengthened T(1/2ß) and AUC(0→∞) values. The mean T(1/2ß) value of PEGylated liposomal honokiol and free honokiol were 26.09 min and 13.46 min, respectively. The AUC(0→∞) ratio of PEGylated liposomal honokiol to free honokiol was about 1.85-fold (219.24 µg/mL min/118.68 µg/mL min) (P=0.000). Examination of protein binding ability showed that honokiol with 0.5, 8.0 and 20 µg/mL concentrations in human plasma achieved the percent of bound between 60% and 65%. The results suggested that PEGylated liposomal honokiol improved the solubility, increased the drug concentration in plasma, and withstanded the clearance. Besides, the percent of protein bound of honokiol in human plasma was between 60% and 65%.

Clinical pharmacokinetics of paclitaxel liposome with a new route of administration in human based on the analysis with ultra performance liquid chromatography.

We investigated the clinical pharmacokinetics of paclitaxel liposome with a new route of administration, which was intrapleural infusion, in nine advanced nonsmall-cell lung cancer (NSCLC) patients with malignant pleural effusions after a single administration. Paclitaxel concentrations were measured in pleural fluid and plasma using a simple and rapid ultra performance liquid chromatography (UPLC) method following intra- and inter-day validations. In subjects, AUC(0-96 h) values in pleural fluid and plasma were 17831 ± 6439 µg h/mL and 778 ± 328 µg h/mL, respectively, and T(max) values were initial time and 6.67 h after administration and the corresponding C(max) values were 558 ± 44 µg/mL and 12.89 ± 6.86 µg/mL, respectively. The T(1/2,IP), CL(IP) and Vd(IP) values in pleural fluid were 76 ± 48 h, 0.005 ± 0.002 L/h m(2) and 0.53 ± 0.23 L/m(2), respectively. The T(1/2,pla), CL(pla), and Vd(pla) values in plasma were 68.34 ± 56.74 h, 0.184 ± 0.080 L/h m(2), and 17.53 ± 16.57 L/m(2), respectively. However, some paclitaxel concentrations from several patients in plasma could not be detected at some designed time-points. Our results might offer new opportunities to design and determine individually appropriate therapeutic dosage regimens based on a pharmacokinetic profile.

A phase I clinical and pharmacokinetic study of paclitaxel liposome infused in non-small cell lung cancer patients with malignant pleural effusions.

PURPOSE: To investigate the feasibility, pharmacokinetics, efficacy and toxicity of intrapleural paclitaxel liposome injection in non-small cell lung cancer (NSCLC) patients with malignant pleural effusions. PATIENTS AND METHODS: Twelve of 15 NSCLC patients with malignant pleural effusions were treated with paclitaxel liposome and three were treated with free paclitaxel. Adequate pleural fluid, blood and urine were collected for pharmacokinetic study. The clinical efficacy and toxicity were synthetically evaluated according to the correlative criteria. RESULTS: The overall toxicity of paclitaxel liposome was lower than that of free paclitaxel. In the patients treated with paclitaxel liposome, there were minimal local chest pain, anaphylaxis, anaemia, neutropaenia and hepatotoxicity. The complete response rates of pleural effusion at the first, second, third and sixth month were, respectively, 27.3%, 18.2%, 9.1% and 9.1%, and overall response rates were 90.9%, 72.7%, 63.6% and 54.5%, respectively. Pharmacokinetic study showed that mean C(max,IP), T(1/2) and AUC(0-->96,IP) in pleural fluid were, respectively, about 2-fold, 2-fold and 2.5-fold than those of free paclitaxel, and AUC(0-->96,Pla) in plasma was also much higher than that of free paclitaxel, however, excretory rate in 24h from urine was lower than that of free paclitaxel. CONCLUSIONS: This study demonstrated that paclitaxel liposome was a more useful agent than free paclitaxel for the treatment of malignant pleural effusions because of its relatively low toxicity and distinct pharmacokinetic characteristics. The phase II study of a large number of patients was recommended to confirm this finding.

Polymeric matrix for drug delivery: honokiol-loaded PCL-PEG-PCL nanoparticles in PEG-PCL-PEG thermosensitive hydrogel.

In this article, we demonstrated a novel injectable polymer matrix: honokiol (HK) loaded poly (epsilon-caprolactone)-poly(ethylene glycol)-poly(epsilon-caprolactone) (PCL-PEG-PCL, PCEC) nanoparticles in thermosensitive poly(ethylene glycol)-poly(epsilon-caprolactone)-poly(ethylene glycol) (PEG-PCL-PEG, PECE) hydrogel for the drug local delivery. First, HK, as a model hydrophobic drug, was loaded into PCL-PEG-PCL nanoparticles by emulsion solvent evaporation method to overcome its poor water solubility. Then, the HK-loaded PCEC nanoparticles (HK-PCEC) were incorporated into thermosensitive PEG-PCL-PEG hydrogel, which was sol at low temperature and could gel as a depot for sustained release of drug in situ after topical injection. The HK-PCEC incorporated PECE hydrogel (HK-PCEC-PECE) was biodegradable and could be gradually eliminated from the injection site in about 2 weeks after subcutaneously injected into mice. The in vitro release studies indicated that HK could be released from HK-PCEC and HK-PCEC-PECE in a sustained manner. Such biodegradable smart drug-delivery system might have great potential application in injectable hydrophobic drug local delivery system.

Improved tumor-targeting drug delivery and therapeutic efficacy by cationic liposome modified with truncated bFGF peptide.

Fibroblast growth factor receptors (FGFRs), overexpressed on the surface of a variety of tumor cells and on tumor neovasculature in situ, are potential targets for tumor- and vascular-targeting therapy. This study aimed to develop a FGFR-mediated drug delivery system to target chemotherapeutic agents to FGFR-overexpressed tumor cells and tumor neovasculature endothelial cells in vitro and in vivo. Here we designed a truncated human basic fibroblast growth factor peptide (tbFGF), which was attached to the surface of cationic liposomal doxorubicin (LPs-DOX) and paclitaxel (LPs-PTX) via electrostatic force. Then we characterized the tbFGF-modified liposome (tbFGF-LPs) and examined internalization of doxorubicin in tumor cells (TRAMP-C1, B16) and HUVEC cells in vitro. In vivo, we evaluated the biodistribution and antitumor efficacy of tbFGF-LPs-DOX and tbFGF-LPs-PTX in C57BL/6J mice bearing TRAMP-C1 prostate carcinoma and B16 melanoma, respectively. The tbFGF-LPs-DOX significantly improved the uptake of doxorubicin in TRAMP-C1, B16 and HUVEC cells, respectively. Biodistribution study in B16 tumor-bearing mice showed that tbFGF-LPs-PTX achieved 7.1-fold (72.827+/-7.321mgh/L vs 10.292+/-0.775mgh/L, mean+/-SD, P<0.01) accumulation of paclitaxel in tumor tissue than those of free paclitaxel. More importantly, treatment of tumor-bearing mice with tbFGF-LPs-DOX and tbFGF-LPs-PTX showed the significant inhibition in tumor growth and improvement in survival rate as compared with mice treated with free and liposomal drugs in TRAMP-C1 and B16 tumor models, respectively. Furthermore, repeated intravenous administration of tbFGF-LPs-DOX/PTX did not induce anti-bFGF antibodies. These results suggested that this FGFR-mediated drug delivery system may provide a new treatment strategy for tumors which overexpress FGFRs.