Co-self-assembled nanoaggregates of BODIPY amphiphiles for dual colour imaging of live cells.

Co-self-assembled vesicular nanoparticles of two structurally comparable amphiphilic boron-dipyrromethene (BODIPY) dyes with dequenchable dual colour fluorescence were prepared for ratiometric imaging of live cells.

Supramolecular adducts of squaraine and protein for noninvasive tumor imaging and photothermal therapy in vivo.

Extensive efforts have been devoted to the development of near-infrared (NIR) dye-based imaging probes and/or photothermal agents for cancer theranostics in vivo. However, the intrinsic chemical instability and self-aggregation properties of NIR dyes in physiological condition limit their widely applications in the pre-clinic study in living animals. Squaraine dyes are among the most promising NIR fluorophores with high absorption coefficiencies, bright fluorescence and photostability. By introducing dicyanovinyl groups into conventional squaraine (SQ) skeleton. These acceptor-substituted SQ dyes not only show superior NIR fluorescence properties (longer wavelength, higher quantum yield) but also exhibit more chemical robustness. In this work, we demonstrated highly stable and biocompatible supramolecular adducts of SQ and the natural carrier protein, i.e., bovine serum albumin (BSA) (SQ⊂BSA) for tumor targeted imaging and photothermal therapy in vivo. SQ was selectively bound to BSA hydrophobic domain via hydrophobic and hydrogen bonding interactions with up to 80-fold enhanced fluorescence intensity. By covalently conjugating target ligands to BSA, the SQ⊂BSA was capable of targeting tumor sites and allowed for monitoring the time-dependent biodistribution of SQ⊂BSA, which consequently determined the protocol of photothermal therapy in vivo. We envision that this supramolecular strategy for selectively binding functional imaging agents and/or drugs into human serum albumin might potentially utilize in the preclinical and even clinic studies in the future.

Molecular structural transformation regulated dynamic disordering of supramolecular vesicles as pH-responsive drug release systems.

The spontaneous release of drug payloads in the whole body always results in the compromised drug bioavailability and ultimate therapeutic efficacy. To achieve enhanced therapeutic efficacy and reduced side effects, pH-responsive targeted drug delivery systems have been studied due to their enhanced tumor accumulation and controllable maximum drug release feature. The present study described a co-assembly constructed by a pH responsive molecule (i.e., malachite green carbinol base (MG)) and liposome for highly efficient doxorubicin (DOX) release in tumor cells (MG-DOX⊂L). The structural transformation of MG effectively regulates the drug release profile in acidic environment. The pH-responsive sensitivity of co-assembly can be fine-tuned by altering the mixing ratios of building blocks with pH responders (i.e., MG molecules). MG-DOX⊂L was beneficial for the DOX release at pH5.0 and showed a higher cytotoxicity in KB cells owing to the pH-responsive drug release in acidic organelles following endocytosis pathway. In vivo tumor targetability and growth inhibition were evaluated in KB cell-xenografted nude mice. We have demonstrated that effective tumor growth inhibition in vivo is attributed to the synergistic contributions from highly efficient cellular entry and responsive intracellular release of DOX from MG-DOX⊂L.

Supramolecular gelatin nanoparticles as matrix metalloproteinase responsive cancer cell imaging probes.

We demonstrate the on-chip preparation of size-controllable supramolecular gelatin nanoparticles (SGNs) with a quantum dot (QD) payload as matrix metalloproteinase (MMP) responsive cancer cell imaging probes.

Anti-bacterial and in vivo tumor treatment by reactive oxygen species generated by magnetic nanoparticles.

Photodynamic therapy is widely used in clinics and for anti-bacterial applications. The major challenge is the limited depth of tissue penetration of light and poor targetability. In this study, magnetite nanoparticles were used as a highly sensitive T2-weighted MR imaging contrast agents to target the tumor and mimic horseradish peroxidase (HRP), which could catalyze the decomposition of hydrogen peroxide to generate reactive oxygen species (ROS) to inhibit the tumor in vivo. In these experiments, MNPs were demonstrated to possess the enzyme-mimicking activity in different pH values, and the activity was dependent on the size of the MNPs: the smaller the size, the higher the activity. We demonstrated that MNPs showed highly efficient anti-bacterial (E. coli) activity in presence of H2O2. The E. coli inhibition ratio reached nearly 100% at optimal concentration. The anti-tumor activity was evaluated through HeLa cell viability under treatment with MNPs and H2O2. Consequently, the cell viability was significantly decreased and more than 80% of HeLa cells were dead after treatment with MNPs and H2O2 under different pH values. MR imaging was used to demonstrate the tumor targetability of 13 nm MNPs in vitro and in vivo. Consequently, the relaxivity of the 13 nm MNPs was determined to be r2 = 104 s-1 mM-1. The MR signal was much more negative and the intensity was significantly diminished with the increase of the concentration of 13 nm MNPs in vitro. The tumor signal was clearly visualized and a 3-fold decrease of the MR signal intensity of the tumor site of the mice was observed after 24 h-post treatment with the 13 nm MNPs. Finally, the tumor inhibition in vivo was investigated using 6 nm MNPs in BALB/c nude female mice bearing subcutaneously implanted HeLa cells on the right flank. The results show statistically significant efficacy in delaying tumor growth from day 6, and an approximately 99% tumor inhibition ratio was shown by the combination of MNPs and H2O2 after treatment for 17 days. By leveraging the passive targeting and MR imaging properties, we expect that the enzyme-mimicking MNPs could be used for cancer theranostics and may open up a new avenue for the treatment of epidermal infections.

[Application of epiglottis with sternohyoid muscle in the surgery for laryngeal cancer].

OBJECTIVE: To explore and evaluate the application of epiglottis with sternohyoid muscle in the surgery for laryngeal cancer. METHODS: Two fifty patients with laryngeal cancer were treated by partial laryngectomy and the laryngeal defects were reconstructed by epiglottic flap and sternohyoid muscle fascia flap. The staging of tumors: T2N0M0 23 cases, T3N1M0 14 cases, T3N2M0 13 cases. All of them received post radical radiotherapy with average 60 Gy. The patients were followed up for 3 to 5 years. Thirty patients underwent neck dissection. RESULTS: The three and five years survival rates were 90% and 80% respectively. The total cases eat breath pronounced well. The decannulation rate was 96%. CONCLUSION: After partial laryngectomy in laryngeal cancer epiglottic flap and sternohyoid muscle fascia flap were performed reconstruction of laryngeal function.

[Changes of brain oxidative stress induced by nano-alumina in ICR mice].

OBJECTIVE: To investigate the brain oxidative stress injury induced by nano-alumina particles in ICR mice. METHODS: Sixty male ICR mice were randomly divided into 6 groups: control group, solvent control group, 100 mg/kg micro-alumina particles group, 3 groups exposed to nano-alumina particles at the doses of 50, 100 and 200 mg/kg. The mice were exposed by nasal drip for 30 days. Then levels of malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-PX) in brain tissues of mice were detected. RESULTS: There was no difference of SOD activity in mouse brain between control group [(17.32 +/- 6.23)U/gHb] and 50 mg/kg nano-alumina particles group [(17.89 +/- 1.82) U/gHb]. The SOD activity [(4.93 +/- 2.30)U/gHb] in 200 mg/kg nano-alumina particles group was significantly lower than that in control group (P < 0.05). The MDA levels in 3 nano-alumina particles groups were (0.76 +/- 0.13), (1.00 +/- 0.30) and (1.16 +/- 0.39)nmol/ml, respectively, which were significantly higher than that [( 0.24 +/- 0.09)nmol/ml] in control group (P < 0.05). The GSH levels in 3 nano-alumina particles groups were (0.72 +/- 0.08), (0.55 +/- 0.19) and (0.61 +/- 0.20)mg/gpro, respectively, which were significantly lower than that [(1.55 +/- 0.34)mg/gpro]] in control group (P < 0.05). The CAT activity in 50 and 100 mg/kg nano-alumina particles groups were (10.40 +/- 3.84) and (10.40 +/- 2.00)U/mgpro, respectively, which were significantly higher than that [(5.79 +/- 0.96) U/mgpro] in control group (P < 0.05). The CAT activity [(3.25 +/- 1.04)U/mgpro] in 200 mg/kg nano-alumina particles group was significantly lower than that in control group (P < 0.05 ). CONCLUSION: Nano-alumina particles can induce the oxidative stress damage in brain tissues of mice.

[Cell toxicity assessment methodologies applied in the study of the toxicity of nano-alumina to nerve cells].

OBJECTIVE: To observe the effect of nano-alumina on nerve cell viability through different detection kits of cell viability, using micro-alumina and nano-carbon as controls. METHODS: Primary culturing nerve cells of mouse in vitro, which were exposed to 7 doses of 0 µmol/L, 62.5 µmol/L, 125.0 µmol/L, 250.0 µmol/L, 500.0 µmol/L, 1.0 mmol/L, 2.0 mmol/L concentrations of nano-alumina (nano-Al), micro alumina (micro-Al) and nano-carbon (nano-C), detecting cell viability (A(570) values) with CCK-8, MTT and LDH methods. RESULTS: (1) The results of CCK-8 kit showed that, in doses of 250.0 µmol/L - 2.0 mmol/L, the cell viability values of nano-alumina (the values of A(570) were 0.878 ± 0.009, 0.823 ± 0.016, 0.647 ± 0.008, 0.594 ± 0.013, respectively) were significantly lower than that of micro-Al (the values of A(570) were 0.960 ± 0.008, 0.951 ± 0.036, 0.833 ± 0.008, 0.708 ± 0.012, respectively) and nano-C (the values of A(570) were 0.977 ± 0.003, 0.973 ± 0.002, 0.924 ± 0.006, 0.891 ± 0.023, respectively). While, comparing nano-Al with the same dose of micro-Al, there was significant difference (the t values were -0.082, -0.128, -0.186, -0.114, respectively, P < 0.01), and so as to the comparison of nano-Al with the same dose of nano-C (the t values were -0.099, -0.150, -0.277, -0.297, respectively, P < 0.01). (2) MTT results showed that in the doses of 500.0 µmol/L and 1.0 mmol/L, the cell viability of nano-Al (the values of A(570) were 0.648 ± 0.095 and 0.575 ± 0.061) were lower than that of micro-Al (the values of A(570) were 0.830 ± 0.044 and 0.816 ± 0.014) and nano-C (the values of A(570) were 0.889 ± 0.009 and 0.765 ± 0.049), and the differences were significant (nano-Al compared with the same dose of micro-Al, the t values were -0.183 and -0.242, P < 0.01; nano-Al compared with the same dose of nano-C, the t values were -0.241 and -0.190, P < 0.01). (3) LDH results showed that in the dose from 125.0 µmol/L to 2.0 mmol/L, the LDH release of nano-Al group (the values of A(570) were 1.862 ± 0.102, 1.905 ± 0.066, 1.930 ± 0.037, 1.946 ± 0.033, 1.967 ± 0.068, respectively) were higher than that of nano-C (the values of A(570) were 1.484 ± 0.110, 1.559 ± 0.039, 1.663 ± 0.014, 1.732 ± 0.076, 1.765 ± 0.073, respectively), and the differences were significant (the t values were -0.377, 0.346, 0.266, 0.213, 0.202, respectively, P < 0.01). In the dose from 125.0 µmol/L to 1.0 mmol/L, the LDH release of nano-Al group were higher than that of micro-Al (the values of A(570) were 1.578 ± 0.011, 1.639 ± 0.025, 1.727 ± 0.024, 1.808 ± 0.020, respectively), and the differences were significant (the t values were 0.284, 0.266, 0.202, 0.172, respectively, P < 0.01). CONCLUSION: The toxicity of nano-Al is greater than nano-C and micro-Al on the viability of nerve cells; LDH is more suitable for detecting changes of cell viability after the effect of nano-materials than CCK-8 and MTT.

Self-assembled nanoparticles of cholesterol-conjugated carboxymethyl curdlan as a novel carrier of epirubicin.

The purpose of this study was to develop nanoparticles made of cholesterol-conjugated carboxymethyl curdlan (CCMC) entrapping epirubicin (EPB) and establish their in vitro and in vivo potential. CCMC was synthesized and characterized by Fourier transform infrared spectra (FT-IR) and proton nuclear magnetic resonance spectra ((1)H NMR). The degrees of substitution (DS) of the cholesterol moiety were 2.3, 3.5 and 6.4, respectively. EPB-loaded CCMC-3.5 nanoparticles were prepared by the remote loading method. The physicochemical characteristics, drug loading efficiency and drug release kinetics of EPB-loaded CCMC-3.5 nanoparticles were characterized. The in vitro release profiles revealed that EPB release was sensitive to the pH as well as the drug loading contents. The cellular cytotoxicity and cellular uptake were accessed by using human cervical carcinoma (HeLa) cells. The EPB-loaded CCMC-3.5 nanoparticles were found to be more cytotoxic and have a broader distribution within the cells than the free EPB. The in vivo pharmacokinetics and biodistribution were investigated after intravenous injection in rats. Promisingly, a 4.0-fold increase in the mean residence time (MRT), a 4.31-fold increase in the half-life time and a 6.69-fold increase in the area under the curve (AUC 0-->infinity) of EPB were achieved for the EPB-loaded CCMC-3.5 self-assembled nanoparticles compared with the free EPB. The drug level was significantly increased in liver at 24 and 72 h; however, it decreased in heart at 8 and 24 h compared with the free EPB. The in vivo anti-tumor study indicated that the EPB-loaded CCMC-3.5 self-assembled nanoparticles showed greater anti-tumor efficacy than the free EPB. Taken together, the novel CCMC self-assembled nanoparticles might have potential application as anti-cancer drug carriers in a drug delivery system due to good results in vitro and in vivo.

Preparation of folate-modified pullulan acetate nanoparticles for tumor-targeted drug delivery.

The purpose of this work was to develop a novel nano-carrier with targeting property to tumor. In this study, pullulan acetate (PA) was synthesized by the acetylation of pullulan to simplify the preparation technique of nanoparticles. Folic acid (FA) was conjugated to PA in order to improve the cancer-targeting activity. The products were characterized by proton nuclear magnetic resonance (¹H NMR) spectroscopy. Epirubicin-loaded nanoparticles were prepared by a solvent diffusion method. The loading efficiencies and EPI content increased with the amount of triethylamine (TEA) increasing in some degree. FPA nanoparticles could incorporate more epirubicin than PA nanoparticles. The folate-modified PA nanoparticles (FPA/EPI NPs) exhibited faster drug release than PA nanoparticles (PA/EPI NPs) in vitro. Confocal image analysis and flow cytometry test revealed that FPA/EPI NPs exhibited a greater extent of cellular uptake than PA/EPI NPs against KB cells over-expressing folate receptors on the surface. FPA/EPI NPs also showed higher cytotoxicity than PA/EPI NPs. The cytotoxic effect of FPA/EPI NPs to KB cells was inhibited by an excess amount of folic acid, suggesting that the binding and/or uptake were mediated by the folate receptor.

Pullulan acetate nanoparticles prepared by solvent diffusion method for epirubicin chemotherapy.

Pullulan acetate (PA) was synthesized by the reaction of pullulan with acetic anhydride in the presence of pyridine. PA was characterized by Fourier transform infrared (FT-IR) and proton nuclear magnetic resonance ((1)H NMR). A solvent diffusion method was employed in the current work to prepare PA nanoparticles. This technique had some advantages compared with other methods. The particle size increased from 185.7 nm to 423.0 nm with the degree of acetylation increasing from 2.71 to 3.0. Drug-loaded PA nanoparticles were prepared for controlled release of epirubicin (EPI). The drug entrapment and drug content increased with the degree substitution of PA increasing. EPI was released from the nanoparticles in a biphasic profile with a fast release rate in the first 10h followed by a slow release in vitro. A higher cytotoxicity against KB cells was found for EPI-loaded PA nanoparticles in comparison with free EPI. Confocal laser scanning microscopy (CLSM) observations indicate that EPI-loaded nanoparticles were internalized and released in the cytoplasmic compartment.