Background and purpose:A pressing obstacle in clinical chemotherapy is drug resistance in breast cancer.A nano-delivery system,which has many advantages as a drug carrier,such as carrying anticancer drugs,can be used effectively to overcome drug resistance in tumors.This paper examined a new nano-delivery system,called calcium phosphate and glycerophosphocholine-mPEG(CAP/GPC-MPEG)composite nanoparticle and its influence on the cellular drug uptake of BCRP-over expressing mitoxantrone(MIT)-resistant breast cancer cell MCF-7/MIT.This paper will also examine its effect on overcoming drug resistance in the MCF-7/MIT cells.Methods:After the calcium phosphate and GPC-mPEG composite nanoparticles were designed and prepared,the entrapment efficiency and in vitro drug release of mitoxantrone-loaded nanoparticles were investigated.Quantitative comparisons were made between cellular uptake of drug-loaded nanoparticles and free drugs.Finally,a confocal laser scanning microscopy Was used to compare the subcellular distribution of drug-loaded nanoparticles and the free drugs.Results:Calcium phosphate and GPC-mPEG composite nanoparticles were nanoporous spherical particles with diameters between 50-100 mn.The MIT-loaded nanoparticles have an entrapment efficiency of(89.45±0.05)%.Although the drug-loaded nanoparticles showed an initial burst of drug release,it was followed by a more sustained release.The concentration of mitoxantrone was 1.89 times treated with MIT-loaded nanoparticles for 1 h compared to that treated with free mitoxantrone for 1 h in MCF-7/MIT cells.and which was 2.33 times in MCF-7 cells.Fluorescent red mitoxantrone appeared in the cytoplasm and nucleus of the MCF-7 and MCF-7,MIT cells treated with MlT-loaded nanoparticles whereas it is almost undetected in both cells treated with free mitoxantrone.Conclusion:Calcium phosphate and GPC-mPEG composite nanoparticles Can promote the cellular uptake and entering of mitoxantrone to the nucleus in MCF-7 and its corresponding BCRP-over expressing MIT-resistant MCF-7/MIT breast cancer cell lines.This nanoparticle is a potential nano-carrier for overcoming drug resistance in tumors.

Objective To investigate the intracellular delivery of siRNAs through the applications of ultrasound targeted microbubbles destruction(UTMD)and biodegradable nanoparticles carriers.Methods Preparation of nanoparticles with and without RGD sequences,parameters optimization via L16(45)orthogonal design,control experiments in groups of optimization,RGD targeted nanoparticles,non-RGD nanoparticles and blank control, and determinations by inverted fluorescence microscope and flow cytometry were performed.Results The uptake and fluorescence intensity of PC-3 cells in group of RGD targeted nanoparticle was (93.49±1.37)% and 34.28±2.06 respectively,and that in group of optimization was (88.33±1.24)% and 30.59±3.93 respectively(P＞0.05).Whereas the uptake and fluorescence intensity of PC-3 cells in group of non-RGD nanoparticles was(71.24±2.80)% and 18.39±0.90 respectively,and that in group of optimization was (84.78±2.13)% and 27.18±0.91 respectively(P＜0.05).ConclusionsThe applications of UTMD with RGD targted nanoparticles cannot increase the intracellular delivery of siRNAs.

In this study, we expressed and purified supercharged green fluorescent protein (+36GFP) that we used to study its combination with nucleic acid and its cell transduction efficiency as carrier of DNA. We transformed pET+36GFP-HA2 plasmid into Escherichia coli BL21 (DE3), then expressed and purified the target protein. We used the protein to transduce a variety of mammalian cell lines including B16 cells, 293 cells, A549 cells and HepG2 cells at specified protein concentrations. Transduction efficiency of the protein was analyzed by flow cytometry. Under laser scanning confocal microscope, we observed visually transduction efficiency of +36GFP protein (100 nmol/L) to A549 cells. We incubated +36GFP with plasmid DNA and analyzed their binding ability with gel mobility shift assay. Then we transduced cells with the mixture of plasmid DNA/+36GFP protein at various ratio and detected the expression of reporter gene by using laser scanning confocal microscope and flow cytometry. The experimental results demonstrate that +36GFP had high transduction efficiency, and as the concentration increased, the efficiency improved in a dose-dependent manner. Gel mobility shift assay indicates that +36GFP could bind to plasmid DNA, blocking the migration of DNA in the gel in a concentration-dependent manner. After the plasmid wrapped by +36GFP penetrated into cells, the cells could express target protein efficiently, proving that +36GFP had the ability to carry nucleic acids into cells. Sucussful expression and purification of +36GFP protein confirms its high efficiency of cell transduction and its ability as carrier to deliver exogenous nucleic acids into cells.
Cell Line, Tumor ; DNA ; genetics ; metabolism ; Escherichia coli ; genetics ; metabolism ; Green Fluorescent Proteins ; biosynthesis ; genetics ; pharmacology ; Humans ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; pharmacology ; Transduction, Genetic ; methods ; Transfection

Physical exercise of moderate intensity is becoming readily accepted as an adjunct therapy to enhance curative effects of chemotherapy in patients with breast cancer. In this study, we investigated the putative effect of physical exercise on inhibition of breast cancer and the possible mechanism therein involoved. Balb/c female mice were transplanted with BCAP-37 breast xenografts and randomly assigned to four groups: (a) saline control, (b) exercise-only, (c) DHAQ-loaded NPs, (d) exercise + DHAQ-loaded NPs. The mice in exercise groups performed progressive wheel running up to 15 m/min for 30 minutes, 6 d/wk for 4 weeks. Tumor growth delay was significantly longer in the DHAQ-loaded NPs group and the exercise + DHAQ-loaded NPs groups compared with that in the control group (P < 0.05; P < 0.01, respectively). Tumor volume and the value of hemoglobin (HGB) showed significant difference between the DHAQ-loaded NPs and exercise + DHAQ-loaded NPs groups (P < 0.05), suggesting that physical exercise of moderate intensity can significantly induce an influence of DHAQ-loaded NPs on delay in tumor growth, and can enhance the anti-tumor efficacy of DHAQ-loaded PLA-PLL-RGD NPs. It is a contributor to adjuvant therapy for breast cancer.
Animals ; Antineoplastic Agents ; administration & dosage ; Drug Carriers ; administration & dosage ; Drug Delivery Systems ; Exercise Therapy ; Female ; Mammary Neoplasms, Experimental ; therapy ; Mice ; Mice, Inbred BALB C ; Mitoxantrone ; administration & dosage ; Nanoparticles ; administration & dosage ; Random Allocation

Objective To explore the changes and clinical significance of joint fluid TNF-α and TNF-β1 levels in patients with knee osteoarthritis (KOA). Methods A total of 90 patients with KOA hospitalized in our hospital were selected. They were assigned to group A with 30 patients at early stage, group B with 30 patients at medium stage,and group C with 30 patients at advanced stage according to the stage of X ray; 30 healthy volunteers were in the con-trol group. Levels of joint fluid TNF-αand TNF-β1 were tested in four groups of patients. Results Levels of joint fluid TNF-β1 at medium and advanced stages of KOA were significantly lower than those in the control group, and the dif-ferences were significant (P<0.01); Levels of joint fluid TNF-α at medium and advanced stages of KOA were signifi-cantly higher than those in the control group, and the differences were significant(P<0.01); the difference of levels of joint fluid TNF-α and TNF-β1 at early stage of KOA was not significant compared with those in the control group(P>0.05);levels of TNF-α/TNF-β1 at early,medium and advanced stage of KOA were significantly higher than those in the control group(P<0.01);TNF-αwas positively correlated with KOA stage(r=0.930,P<0.01);TNF-β1 was nega-tively correlated with KOA stage(r=-0.849,P<0.01);TNF-α/TNF-β1 was positively correlated with KOA stage(r=0.828,P<0.01). Conclusion TNF-α and TNF-β1 are involved in the formation and progression of OA, and levels of joint fluid TNF-α and TNF-β1 are able to reflect the severity of KOA lesions; joint fluid TNF-α/TNF-β1 is able to detect KOA early.