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OBJECTIVE To study the effects of transferrin-targeting peptide T7 (7pep) on intracellular transportation of polyethylene glycol-polycaprolactone (PEG-PCL) micelles in human cervical cancer HeLa cells. METHODS Using coumarin-6 (C6) as fluorescent indicator probe, both coumarin-6 (C6)-loaded PEG-PCL (PEG-PCL-C6) micelles and 7pep-modified PEG- PCL (7pep-PEG-PCL-C6) micelles were prepared by film-dispersion method. The particle size, polydispersity index and appearance morphology were compared between two types of micelles; the real-time uptake of two types of micelles by HeLa cells was compared, and the colocalization of two types of micelles with early endosomes (EE), endocytic recycling compartments (ERC) and late endosomes (LE) after entry into the cells was observed. RESULTS The particle sizes of PEG-PCL-C6 and 7pep-PEG-PCL- C6 micelles were(75.0±2.3)and(82.0±1.5)nm; the polymer dispersity indexes were 0.17±0.20 and 0.17±0.32, respectively, with a regular spherical appearance. The colocalization results showed that entry speed and amount of 7pep-PEG-PCL-C6 micelles were significantly faster/more than those of PEG-PCL-C6 micelles. 7pep-PEG-PCL-C6 micelles entered EE faster than PEG-PCL-C6 micelles, while PEG-PCL-C6 micelles entered ERC at a faster rate than 7pep-PEG-PCL-C6 micelles, and both PEG-PCL-C6 micelles and 7pep-PEG-PCL-C6 micelles tended to accumulate gradually in LE; Pearson coefficient, signal overlap ratio, and colocalization ratio of 7pep-PEG-PCL-C6 micelles with LE were significantly lower 60 minutes after entering the cell than those 30 minutes after entering the cell (P<0.05 or P<0.01). CONCLUSIONS Targeting 7pep modification can increase the entry speed and amount of PEG-PCL-C6 micelles, and also alter their intracellular transportation behavior.
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@#Abstract: The aim of this study was to prepare a high drug-carrying capacity micellar drug delivery system (CTD@Sol) of the polymer zebra tetracycline and to preliminarily investigate the feasibility of this drug delivery system for the treatment of breast cancer. Firstly, CTD@Sol was prepared using sol as the carrier material and CTD as the model drug, and its pharmacological properties such as appearance and morphology, particle size, potential and in vitro release were evaluated. The growth inhibitory and apoptotic effects of CTD@Sol on breast cancer (4T1) cells were investigated by MTT assay and Annexin V-FITC/PI double staining assay; the uptake efficiency of 4T1 to this delivery system was investigated by flow cytometry; and the in vivo tissue distribution of the delivery system and the targeting of tumour tissues were investigated by small animal in vivo imaging technique. The results showed that CTD@Sol appeared as a light pale blue creamy white colour, with an average particle size of (159.73 ± 1.96) nm, a PDI of 0.198 ± 0.006, Zeta potential of –(47.60 ± 1.77) mV, an encapsulation rate of (90.29 ± 1.69)% and a drug loading capacity of (45.00 ± 0. 84)%; the in vitro release and haemolysis experiments showed that the drug release rate of CTD@Sol in acidic environment (pH 5.5) was significantly faster than that in neutral environment (pH 7.4), suggesting that the system is acid-sensitive and has good biosafety under endocytosed pH conditions. Cellular uptake, cytotoxicity and apoptosis experiments showed that CTD@Sol was more lethal to 4T1 cells, and the sol-gel polymer micelles as a drug delivery vehicle could significantly improve the cellular uptake efficiency of the drug; in vivo experiments showed that the delivery system had a significant targeting effect on tumour tissues.In conclusion, this study has successfully produced a CTD@Sol drug delivery system with high drug loading capacity (>45%), good pharmacological performance, strong targeting and biosafety, which has the potential to be used in the treatment of breast cancer.
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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.
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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.
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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.
Subject(s)
Humans , Amyloid beta-Protein Precursor/chemistry , Micelles , Amyloid Precursor Protein Secretases/metabolism , Magnetic Resonance Spectroscopy , Recombinant ProteinsABSTRACT
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.
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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.
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@#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.
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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.
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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.
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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
Subject(s)
Biocompatible Materials , Hydrogels , Micelles , Nanocomposites , PolymersABSTRACT
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.
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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.
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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.
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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.
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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 (
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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.
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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).
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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.
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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.