pH and GSH dual-responsive silybin nano-micelles for inhibition of breast cancer activity and metastasis in vitro / 药学学报

The clinical tumor therapy was greatly challenged due to the complex characteristics of tumor microenvironment, however, which also provide arena for novel therapeutic strategies. In this study, poly(2-ethyl-2-oxazoline)-poly(lactic acid)-SS-poly(β-amino ester (PEOz-PLA-SS-PBAE) triblock copolymers with pH and GSH double response were synthesized, polymer micelles were prepared by thin film hydration method for loading of silybin to improve its antitumor activity. The critical micelle concentration was determined by pyrene fluorescence method as 1.8 μg·mL-1. The particle size was 155.30 ± 1.80 nm as determined by dynamic light scattering, with polydispersity index of 0.168 ± 0.004. The drug loading and entrapment efficiency of the micelles were determined by HPLC as (5.48 ± 0.04)% and (68.52 ± 0.48)%, respectively. The in vitro drug release profiles showed that the micelles have low pH sensitivity and high GSH responsiveness, and exhibited sustained release profiles. The good biocompatibility of the material was proved by measuring the hemolysis rate and cytotoxicity of the blank micelle. The cytotoxicity and apoptosis rate of tumor cells showed that the drug loaded PEOz-PLA-SS-PBAE micelles had significant inhibitory effect and apoptosis-inducing effect on MDA-MB-231 cells. The results of wounding healing assay and Transwell invasion test showed that the drug loaded PEOz-PLA-SS-PBAE micelles could significantly inhibit the metastasis of MDA-MB-231 cells. The PEOz-PLA-SS-PBAE drug-loaded micelles prepared in this study have good inhibitory effect on tumor growth and anti-tumor metastasis in vitro, which lays the foundation for the further application of silybin.

Expression, purification and micelle reconstruction of the transmembrane domain of the human amyloid precursor protein for NMR studies / 生物工程学报

The multiple-step cleavage of amyloid precursor protein (APP) generates amyloid-β peptides (Aβ), highly toxic molecules causing Alzheimer's disease (AD). The nonspecific cleavage between the transmembrane region of APP (APPTM) and γ-secretase is the key step of Aβ generation. Reconstituting APPTM under physiologically-relevant conditions is crucial to investigate how it interacts with γ-secretase and for future AD drug discovery. Although producing recombinant APPTM was reported before, the large scale purification was hindered by the use of biological protease in the presence of membrane protein. Here, we expressed recombinant APPTM in Escherichia coli using the pMM-LR6 vector and recovered the fusion protein from inclusion bodies. By combining Ni-NTA chromatography, cyanogen bromide cleavage, and reverse phase high performance liquid chromatography (RP-HPLC), isotopically-labeled APPTM was obtained in high yield and high purity. The reconstitution of APPTM into dodecylphosphocholine (DPC) micelle generated mono dispersed 2D 15N-1H HSQC spectra in high quality. We successfully established an efficient and reliable method for the expression, purification and reconstruction of APPTM, which may facilitate future investigation of APPTM and its complex in more native like membrane mimetics such as bicelle and nanodiscs.

ROS-removing nano-medicine for navigating inflammatory microenvironment to enhance anti-epileptic therapy

As a neurological disorder in the brain, epilepsy is not only associated with abnormal synchronized discharging of neurons, but also inseparable from non-neuronal elements in the altered microenvironment. Anti-epileptic drugs (AEDs) merely focusing on neuronal circuits frequently turn out deficient, which is necessitating comprehensive strategies of medications to cover over-exciting neurons, activated glial cells, oxidative stress and chronic inflammation synchronously. Therefore, we would report the design of a polymeric micelle drug delivery system that was functioned with brain targeting and cerebral microenvironment modulation. In brief, reactive oxygen species (ROS)-sensitive phenylboronic ester was conjugated with poly-ethylene glycol (PEG) to form amphiphilic copolymers. Additionally, dehydroascorbic acid (DHAA), an analogue of glucose, was applied to target glucose transporter 1 (GLUT1) and facilitate micelle penetration across the blood‒brain barrier (BBB). A classic hydrophobic AED, lamotrigine (LTG), was encapsulated in the micelles via self-assembly. When administrated and transferred across the BBB, ROS-scavenging polymers were expected to integrate anti-oxidation, anti-inflammation and neuro-electric modulation into one strategy. Moreover, micelles would alter LTG distribution in vivo with improved efficacy. Overall, the combined anti-epileptic therapy might provide effective opinions on how to maximize neuroprotection during early epileptogenesis.

Effect of temperature and chain length of added primary amines on the sphere to rod transition of aqueous ionic micelles

The importance of micelles as templates for nanomaterials is growing day by day. This resulted in an increasing interest for micelles in different sizes and shapes. Addition of n-amines to micellar solutions was found to bring change in the shape of the micelles from sphere to rod in aqueous ionic micellar solutions. The change in shape is qualitatively obtained from sudden change in the slope of pH versus amine concentration plots because the degree or protonation of n-alkylamines depends on the shape of micelles. In the present investigation, pH is measured at different temperatures to elucidate the influence of addition of n-amines on sphere-to-rod transition in aqueous micellar solutions. The surfactants employed in the present investigation are cetyltrimethyl ammonium bromide (CTAB), cetylpyridinium chloride (CPC), and sodium dodecyl sulphate (SDS).As the amine concentration is increased, the pH increases linearly at certain amine concentration and the slope of the resulting straight line changes on further addition of amine. It is noticed that increasing temperature requires more amine for structural transition of aqueous ionic micelles. It is also observed that the effectiveness of added amines leading to shape transition from sphere to rod is in the order of C8NH2>C7NH2> C6NH2.

Construction and anti-tumor efficiency evaluation of redox-responsive micelles for the co-delivery of IR-780 and 18β-glycyrrhetinic acid / 药学学报

Photothermal therapy (PTT) is a highly effective anti-tumor method. However, when laser radiation was used to ablate tumors, it usually triggers a series of inflammatory reactions, promoting the further development of tumors and affecting the effect of anti-tumor therapy. Therefore, it is an effective method to improve the anti-tumor effect by suppressing the inflammatory response through the precise targeted delivery of anti-inflammatory drug while realizing the photothermal treatment of tumors. To this end, the redox-responsive linker 3,3'-dithiodipropionic acid was used to bond the classic hydrophobic anti-inflammatory drug 18β-glycyrrhetinic acid (18β-GA) and the hydrophilic fragment methoxy-polyethylene glycol (mPEG-NH2) to obtain redox-responsive amphiphilic polymer PEG-DA-GA in this study. Then, photothermal agent IR-780 was encapsulated to prepare redox-responsive polymer micelle PDG/IR-780 NPs. The PDG/IR-780 NPs exhibited uniform particle size of 80.2 ± 5.3 nm and the polydispersity index (PDI) was 0.215 ± 0.079. All animal experiments followed the ethical requirements formulated by the Ethics Committee of Sichuan University. The results showed that PDG/IR-780 NPs could respond to the abundant glutathione (GSH) in tumor cells to promote the disintegration of nanoparticle and the release of 18β-GA, thus significantly improved the killing efficiency on 4T1 cells, when compared with the non-redox-responsive control PSG/IR-780 NPs. When the concentration of 18β-GA was 50 μg·mL-1, the cell viability of 4T1 cells in the PDG/IR-780 NPs group was only (19.29 ± 1.80) %, which was significantly lower than the result of in PSG/IR-780 NPs group (29.30 ± 1.37) %. The results of frozen sections of tumor tissues showed that the designed PDG NPs can promote the tumor-targeted distribution of drugs compared with the free drug group. Eventually, PDG/IR-780 NPs achieved wonderful anti-tumor efficacy on 4T1 triple-negative breast cancer model, revealing the new possibility of the combined therapy strategy of photothermal and anti-inflammatory therapy.

Preparation and characterization of dasatinib albumin micelles / 中国药科大学学报

@#In this study, a polyethylene glycol and dodecaldehyde modified bovine serum albumin (PEG-DSA) was developed, and its feasibility as a new high-efficiency micellar carrier for dasatinib (DAS) was explored.Circular dichroism, 1H NMR, elemental analysis, FT-IR and other methods were used to characterize the material structure and the single factor method was used to optimize the process of PEG-DSA/DAS micelles and non-PEGylated control micelles DSA/DAS.The results indicated that the optimal formulation was obtained with a mass ratio of 4∶1 between PEG-DSA and DAS, with average particle size of (37.21 ± 0.21) nm, polydispersion index (PDI) of (0.24 ± 0.04), Zeta potential of ? (15.68 ± 0.19) mV, drug loading (DL) capacity of (10.22 ± 0.34) %, and encapsulation efficiency (EE) of (42.73 ± 1.15) %. Compared with the currently reported nano-formulations of DAS, the drug loading of PEG-DSA/DAS micellar formulations was significantly increased with potential for further development.

Preparation and characterization of linolenic acid-chitosan micelle for doxorubicin oral delivery and its in situ intestinal absorption in rats / 药学学报

In this study, a novel oral drug delivery system based on linolenic acid-modified chitosan (CS-LA) micelle was developed to improve the oral bioavailability of doxorubicin (DOX), which was proven by its in vivo intestinal absorption in rats. The DOX-loaded CS-LA micelles (CS-LA@DOX) were prepared by the dialysis method. The synthesized micelle material was identified by proton nuclear magnetic resonance spectroscopy (1H-NMR) and Fourier transform infrared spectroscopy (FT-IR). A series of the micelle properties, including particle size distribution, zeta potential, encapsulation efficiency (EE), drug loading (DL), micromorphology, polymorphy, and critical micelle concentration (CMC) were characterized or tested. The in vitro release of micelles was observed by the dialysis method, and the absorption-promoting effect of micelles was investigated by intestinal circulation experiments in rats. The animal welfare and experimental procedures were in accordance with the regulations of the Animal Ethics Committee of Guilin Medical University. The results of 1H-NMR and FT-IR showed that CS and LA were covalently bound via an amide linkage. The DOX encapsulated in the micelle core was in an amorphous state. The as-prepared micelles in the transmission electron microscope (TEM) image showed regular spherical shapes and uniform sizes with a series of excellent characteristics including (119.2 ± 2.1) nm of mean particle size [polymer dispersity index (PDI), 0.190 ± 0.08], +12.1 mV of zeta potential, (70.23 ± 0.74) % of EE, (8.77 ± 0.02) % of DL and 51.75 μg·mL-1 of CMC. Compared with the reference, DOX hydrochloride, the proposed micelle drug delivery system showed an obvious sustained-release effect in vitro release; and enhanced drug absorption in the small intestine of rats.

A BRD4 PROTAC nanodrug for glioma therapy via the intervention of tumor cells proliferation, apoptosis and M2 macrophages polarization

Glioma is a primary aggressive brain tumor with high recurrence rate. The poor efficiency of chemotherapeutic drugs crossing the blood‒brain barrier (BBB) is well-known as one of the main challenges for anti-glioma therapy. Moreover, massive infiltrated tumor-associated macrophages (TAMs) in glioma further thwart the drug efficacy. Herein, a therapeutic nanosystem (SPP-ARV-825) is constructed by incorporating the BRD4-degrading proteolytic targeting chimera (PROTAC) ARV-825 into the complex micelle (SPP) composed of substance P (SP) peptide-modified poly(ethylene glycol)-poly(d,l-lactic acid)(SP-PEG-PDLLA) and methoxy poly(ethylene glycol)-poly(d,l-lactic acid) (mPEG-PDLLA, PP), which could penetrate BBB and target brain tumor. Subsequently, released drug engenders antitumor effect via attenuating cells proliferation, inducing cells apoptosis and suppressing M2 macrophages polarization through the inhibition of IRF4 promoter transcription and phosphorylation of STAT6, STAT3 and AKT. Taken together, our work demonstrates the versatile role and therapeutic efficacy of SPP-ARV-825 micelle against glioma, which may provide a novel strategy for glioma therapy in future.

Preparation and applications of the polymeric micelle/hydrogel nanocomposites as biomaterials / 生物医学工程学杂志

Polymeric hydrogels have been widely researched as drug delivery systems, wound dressings and tissue engineering scaffolds due to their unique properties such as good biocompatibility, shaping ability and similar properties to extracellular matrix. However, further development of conventional hydrogels for biomedical applications is still limited by their poor mechanical properties and self-healing properties. Currently, nanocomposite hydrogels with excellent properties and customized functions can be obtained by introducing nanoparticles into their network, and different types of nanoparticles, including carbon-based, polymer-based, inorganic-based and metal-based nanoparticle, are commonly used. Nanocomposite hydrogels incorporated with polymeric micelles can not only enhance the mechanical properties, self-healing properties and chemical properties of hydrogels, but also improve the

Preparation and stability evaluation of artemether-loaded mixed micelles composed of the sodium glycocholate and soybean lecithin / 药学学报

In this study, artemether (ARM)-loaded mixed micelles (MM) composed of the sodium glycocholate (SGC) and soybean lecithin (SL) were prepared by film dispersion method. The effects of hydration medium, SL mass ratio and total concentration of excipients on the solubilization of ARM were investigated and the stability of MM was evaluated. Results showed that the particle size distribution of SGC-SL-MM prepared by phosphate buffer solution (PBS, pH 7.4, 0.05 mol·L-1) was uniform, with an average size of 3.58 ± 0.14 nm and the polydispersity index (PDI) value was 0.16 ± 0.04. The solubility of ARM increased significantly from 0.64 ± 0.04 mg·mL-1 to 13.7 ± 0.13 mg·mL-1 along with the concentration of total excipient increasing from 1.0% to 30.0% (w/w). The calculated results of Arrhenius parameter and storage stability showed that the degradation rate constant of ARM in MM was smaller than that in acetonitrile-PBS (pH 7.4) at either 37 ℃ or 60 ℃. The experimental ARM-MM was clear after storing for two months at 25 ℃ and the degradation of ARM was less than 7.0%. In conclusion, the SGC-SL-MM can not only improve the solubility of ARM in aqueous solution, but also improve its chemical stability in aqueous solution at low temperature.

Nanomedicines for the treatment of rheumatoid arthritis: State of art and potential therapeutic strategies

Increasing understanding of the pathogenesis of rheumatoid arthritis (RA) has remarkably promoted the development of effective therapeutic regimens of RA. Nevertheless, the inadequate response to current therapies in a proportion of patients, the systemic toxicity accompanied by long-term administration or distribution in non-targeted sites and the comprised efficacy caused by undesirable bioavailability, are still unsettled problems lying across the full remission of RA. So far, these existing limitations have inspired comprehensive academic researches on nanomedicines for RA treatment. A variety of versatile nanocarriers with controllable physicochemical properties, tailorable drug release pattern or active targeting ability were fabricated to enhance the drug delivery efficiency in RA treatment. This review aims to provide an up-to-date progress regarding to RA treatment using nanomedicines in the last 5 years and concisely discuss the potential application of several newly emerged therapeutic strategies such as inducing the antigen-specific tolerance, pro-resolving therapy or regulating the immunometabolism for RA treatments.

Anti-hepatoma activity of targeted pluronic f127/formononetin nanocomposite system in vitro / 中国组织工程研究

BACKGROUND: Natural flavonoid formononetin (FN) is traditional Chinese medicine extract and has anticancer effect, but the hydrophobic structure and short half-life in vivo limit their clinical applications. OBJECTIVE: To prepare FN loaded pluronic (PF)-folic acid (FA) conjugated micelles (FN-PF-FA) and to test in vitro drug release and anticancer activity. METHODS: FA coupling PF was prepared by carbodiimide crosslinker chemical method. FN-PF-FA micelles were prepared by film hydration method. The encapsulation efficiency, drug loading and drug release performance of FN-PF and FN-PF-FA micelles were measured. The in vitro anti-cancer activity of flavin, FN-PF micelles, and FN-PF-FA micelles on folic acid-overexpressing human liver cancer HepG2 cells was measured by in vitro thiohodamine B experiment. RESULTS AND CONCLUSION: (1) The encapsulation efficiency of FN-PF and FN-PF-FA micelles was (84.12±2.15)% and (82.50±1.78)%, respectively, and the drug loading was (21.33±2.27)% and (19.73±1.58)%, respectively. (2) The release rate of both micelles in acidic environment was faster than that in alkaline environment. In the same condition, the release rate of FN-PF-FA micelles was slower than that of FN-PF micelles. (3) At the same drug concentration, the ability of FN-PF micelles and FN-PF-FA micelles to inhibit the proliferation of human liver cancer HepG2 cells was stronger than that of free FN (P < 0.05). Moreover, the inhibitory effect of FN-PF-FA micelles was stronger than that of FN-PF micelles (P < 0.05). (4) The order of drug concentration required to inhibit tumors was FN-PF-FA < FN-PF < free FN, and there was a significant difference between groups (P < 0.01). (5) Results suggested that FN-PF-FA micelles had the potential to target the release of anticancer drugs.

Study on the Effects of Self-assembly Micelles of Euphorbiae Semen Fatty Oil on Intestinal Absorption of 4 Kinds of Euphorbia in Rats / 中国药房

OBJECTIVE：To study the effects of different amounts of Euphorbiae Semen fatty oil in self-assembly micelles on intestinal absorption of 4 kinds of euphorbia （euphorbia L 1，L2，L3，L8）in rats. METHODS ：The self-assembled micelle solution containing 4 kinds of euphorbia was prepared by adding 4 kinds of euphorbia （40 mg/L）in excess ，using the fatty oil of Euphorbia Semen（0.2，0.4，1，4 g/L）and sodium deoxycholate as carriers. Totally 60 rats were collected to establish in-situ one-way intestinal perfusion model. Different intestinal segments （duodenum，jejunum，ileum，colon）were perfused with drug-containing intestinal perfusion fluid according to different dosage of Euphorbiae Semen fatty oil. HPLC method was adopted to determine the contents of 4 kinds of euphorbia in the intestinal perfusate before and after perfusion. The absorption rate constant （Ka）and apparent absorption coefficient （Peff）of 4 kinds of euphorbia in different intestinal segments were calculated. The ileum segment with better absorption was selected as the object to investigate and calculate the ac cumulative absorption of 4 kinds of euphorbia. RESULTS：The self-assembled micelles formed by different concentrations of fatty oil of Euphorbiae Semen could significantly increase the absorption of 4 kinds of euphorbia in different intestinal segments to different extents. When the dosage of Euphorbiae Semen fatty oil was 0.4 g/L，the intestinal absorption effect of 4 kinds of euphorbia were all the best ；the Peff was significantly increased，compared with no fat oil group （P＜0.05 or P＜ . According to the order of Ka and Peff of each intestinal ： segment in different fatty oil dosage groups ，the absorption 0531-89628590。E-mail：1310394709@qq.com effect of 4 kinds of euphorbia in each intestinal segment was the best in jejunum and the worst in colon. Compared with no fatty oil group ，when the amount of Euphorbiae Semen fatty oil w as 0.2-4 g/L，accumulative amount of 4 kinds of euphorbia in the ileum of rats increased significantly （P＜0.05 or P＜0.01）， and the highest in 0.4 g/L Euphorbiae Semen fatty oil group. CONCLUSIONS ：The self-assembly micelle s composed of Euphorbiae Semen fatty oil and deoxycholate can increase the absorption of euphorbia L 1，L2，L3，L8 in each intestinal segment to different extent，and the jejunum is the main absorption segment.

Preparation and Preliminary Evaluation of Paclitaxel-loaded TPGS-CR Polymeric Micelles / 中国药学杂志

OBJECTIVE: To prepare paclitaxel loaded D-α-tocopheryl polyethylene glycol 1000 succinate(TPGS)-modified carboxymethyl chitosan-rhein polymeric micelles (PTX/TPGS-CR PMs) and preliminarily evaluate their performance. METHODS: PTX/TPGS-CR PMs was prepared by dialysis method, and the preparation procedure of PTX/TPGS-CR PMs was optimized by single factor with the drug loading, encapsulation rate and particle size as the indicators, then the optimized preparation procedure was verified. The safety of PTX/TPGS-CR PMs was initially investigated by the hemolysis test and the vascular irritation test. The cytotoxicity of PTX/TPGS-CR PMs in Hela cells was studied by MTT assay. Cell uptake experiments were performed by laser confocal microscopy and flow cytometry to investigate the uptake of PTX/TPGS-CR PMs by Hela cells. RESULTS: The particle size and PDI of PTX/TPGS-CR PMs prepared by the optimized preparation were (197.3±4.4) nm and (0.131±0.021), respectively. The Zeta potential was (-31.8±0.5) mV. The drug loading and encapsulation efficiency were (48.20±3.03)% and (87.26±4.91)%, respectively. The hemolytic test results showed that the hemolysis rate was less than 1.71%. No obvious irritation was observed after intravenous injection. The cytotoxicity of PTX/TPGS-CR PMs in Hela cells was concentration-and time-dependent. Cell uptake experiments showed that PTX/TPGS-CR PMs could be efficiently uptake by Hela cells. CONCLUSION: The PTX/TPGS-CR PMs has high drug loading and encapsulation efficiency, good safety. And they exhibite slightly better antitumor activity in vitro than Taxol®.

HDL Coupled Multimeric Micelles Co-delivery of siRNA and Doxorubicin for Cell Uptake and Reversal of Multidrug Resistance / 中国药学杂志

OBJECTIVE: To prepare siRNA/HDL modified Dox/micelle multimeric polymer(siRNA/HDL-Dox/micelle) by using HDL as a siRNA carrier and a targeting ligand and to realize the effective co-delivery of siRNA and antitumor drug. METHODS: HDL was incubated with chol-siRNA to prepare siRNA/LDL complex, then coupled with Dox/micelle to form siRNA/HDL modified Dox/micelle multimeric polymer (siRNA/HDL-Dox/micelle). The particle size and stability were investigated in different medium. HepG2/ADM with P-glycoprotein(P-gp) over-expressed were used to study the cell uptake, sub-cellular localization and anti-tumor efficacy in vitro. The ability of siRNA to silence target genes at mRNA and protein level was examined by RT-PCR and Western blot. RESULTS: HDL exhibited an efficient binding ability for siRNA and protected siRNA from RNase. The size and surface morphology of siRNA/HDL-Dox/micelle confirmed by TEM showed that most of the micelles were compact and spherical, exhibited a narrow size distribution and good dispersion. The particle size and Zeta potential increased with increasing incubation time in pH 5.3 PBS. The siRNA was efficiently delivered into the cells by encapsulation into HDL, and the expression of P-gp is effectively down-regulated at the mRNA level and the protein level, thereby increasing the accumulation of intracellular Dox and enhancing the antitumor activity. CONCLUSION: siRNA/HDL-Dox/micelle could effectively deliver siRNA and Dox into tumor cells, thereby exerting gene silencing, reversing tumor drug resistance and enhancing anti-tumor effect.

Contruction of Drug Delivery System of Cancer Cell Membrane Coated Nanoparticles and Application in Breast Cancer / 中国药学杂志

OBJECTIVE: To investigate a biomimetic nano-targeted drug modifide by cancer cell membrane and to discuss its efficiency in breast cancer. METHODS: The lac-DOX/DOX was prepared by filming-rehydration method, and the 4T1 cell membrane was extracted at the same time. The lac-DOX /DOX@4T1m was prepared by sonication method.. The morphology of lac-DOX /DOX@4T1m was observed by a transmission electron microscopy. The protein on 4T1 cell membrane was analyzed by gel electrophoresis. The targeting of drugs to homologous cancer cells in vivo and in vitro were evaluated by cell uptake experiments and imaging experiments of small animals. 4T1 tumor-bearing Balb/c mice were built, the anti-tumor efficacy and biosafety of lac-DOX/ DOX@4t1m were evaluated. RESULTS: The prepared lac-DOX /DOX@4T1m have a regular spherical shape with an average particle diameter of (204.8±13.0)nm, and the protein entirety remained on the cell membrane. The results of cell uptake experiments and in vivo imaging experiments of mice showed that lac-DOX/DOX@4T1m can target 4T1 cells. Antitumor test results showed that lac-DOX/ DOX@4T1m could inhibit tumor growth more effectively and significantly reduce the damage to liver function. CONCLUSION: In this study, a bionic nano-drug is successfully prepared, which improve the tumor targeting and therapeutic effect, reduce the toxic effects of adriamycin, and improve the drug safety.

Injectable thermo-responsive nano-hydrogel loading triptolide for the anti-breast cancer enhancement

The clinical application of triptolide (TPL) in tumor therapy has been greatly limited by its toxicity and inefficient delivery. Herein, a localized and sustained-release thermo-sensitive hydrogel was developed for the intra-tumor administration of TPL. Based on the amphiphilic structure of poly (

Interfacial properties and micellization of triblock poly(ethylene glycol)-poly(-caprolactone)-polyethyleneimine copolymers

This study aimed to explore the link between block copolymers' interfacial properties and nanoscale carrier formation and found out the influence of length ratio on these characters to optimize drug delivery system. A library of diblock copolymers of PEG-PCL and triblock copolymers with additional PEI (PEG-PCL-PEI) were synthesized. Subsequently, a systematic isothermal investigation was performed to explore molecular arrangements of copolymers at air/water interface. Then, structural properties and drug encapsulation in self-assembly were investigated with DLS, SLS and TEM. We found the additional hydrogen bond in the PEG-PCL-PEI contributes to film stability upon the hydrophobic interaction compared with PEG-PCL. PEG-PCL-PEI assemble into smaller micelle-like (such as PEG-PCL4006-PEI) or particle-like structure (such as PEG-PCL8636-PEI) determined by their hydrophilic and hydrophobic block ratio. The distinct structural architectures of copolymer are consistent between interface and self-assembly. Despite the disparity of constituent ratio, we discovered the arrangement of both chains guarantees balanced hydrophilic-hydrophobic ratio in self-assembly to form stable construction. Meanwhile, the structural differences were found to have significant influence on model drugs incorporation including docetaxel and siRNA. Taken together, these findings indicate the correlation between molecular arrangement and self-assembly and inspire us to tune block compositions to achieve desired nanostructure and drug loading.

A hyaluronic acid nanogel for melanoma targeted drug delivery / 药学学报

Melanoma is a malignant tumor with a high degree of malignancy. The incidence of melanoma keeps increasing annually. In this study, a melanoma targeted hyaluronic acid (HA) nanogel was synthesized via crosslinking of thiolated HA with terminally functionalized F127-TPGS mixed micelles. Its stability in vitro was evaluated by the average particle size, and the cytotoxicity of the nanogel was investigated by in vitro cell based assays. Next, cell uptake studies were performed to quantitatively and qualitatively investigate the uptake of the nanogels in B16F10 cells. A small sized nanogel with a diameter of 30 nm was synthesized, which was proven to be minimally cytotoxic against both 3T3 or B16F10 cells. Compared with 3T3 cells with low levels of CD44, B16F10 cells with high levels of CD44 showed significantly higher cell uptake efficiency (P<0.05).

Evaluation of tolerance and pharmacodynamics of nano-micelle irinotecan formulation / 中国药科大学学报

@#This study aimed to investigate the improvement of tolance and pharmacodynamics of nano-micelle irinotecan formulation compared with irinotecan hydrochloride injection(Campto). The toxic effects of the two formulations on colorectal cancer cells COLO205, HT-29, HCT-8 and SW480 were tested in vitro. COLO205 tumor-bearing mouse model was constructed. The two preparations were given via tail vein injection to investigate the maximum tolerance dose(MTD)of tumor-bearing mice to the two preparations, and then to explore the improvement of anti-tumor efficacy of nano-micelle irinotecan formulation near the MTD. The results showed that there was no significant difference in the inhibitory effect of the two formulations on the four colorectal cancer cells in vitro. The MTD of nano-micelle irinotecan formulation and Campto was 432. 0 and 276. 5 mg/m2 respectively. Both of the two formulations showed significant anti-tumor effect in vivo, and the relative tumor proliferation rate and tumor wet weight inhibition rate of nano-micelle irinotecan formulation at high dose(345. 6 mg/m2)were significantly better than those of Campto at two doses(177. 0 and 221. 2 mg/m2)(P< 0. 05).