Objective To investigate the effect of local injection of curcumin-loaded mesoporous silica nanoparticles (Cur@MSN) on the repair and treatment of degenerative intervertebral disc tissue in rats, and provide a new strategy for the treatment of intervertebral disc degeneration. Methods Mesoporous silica nanoparticles (MSN) and Cur@MSN were prepared according to the method reported in the literature. Rat nucleus pulposus cells were co-cultured with curcumin and Cur@MSN, respectively, and the growth status and activity of cells in normal environment and inflammatory environment (adding lipopolysaccharide) were observed respectively. Twelve 8-week-old SD rats were randomly divided into 4 groups, including normal group, degeneration group, curcumin group, and Cur@MSN group, with 3 rats in each group. Acupuncture degeneration model was established in coccygeal intervertebral discs (Co7-8, Co8-9) of rats, and corresponding intervention were injected. Imaging, gross pathology, and histological examination were performed after 4 weeks, respectively, to observe the tissue structure and pathological changes of intervertebral discs. Results Under scanning electron microscope, Cur@MSN was spherical in shape, with groove-like pores on its surface. Particle size analysis showed that the particle size of MSN was concentrated in 120-160 nm, and that of Cur@MSN was distributed in 130-170 nm. Zeta potential analysis showed that the average Zeta potential of MSN, curcumin, and Cur@MSN was −12.5, −22.5 and −13.5 mV, respectively. The entrapment efficiency of Cur@MSN was 20.4%, and the drug loading rate was 0.2%. Curcumin released by Cur@MSN in 12 h accounted for about 60% of the total drug dose, and curcumin released in 28 h accounted for about 70%. In cell experiment, there was no significant difference in cell proliferation absorbance among the groups in normal environment (P>0.05), but the cell proliferation absorbance in the Cur@MSN group on the 3rd and 5th day in inflammatory environment was significantly higher than that in the control group and the curcumin group (P<0.01). The percentage of disc height index and the Pfirrmann grade of the Cur@MSN group were better than those of the degeneration group and the curcumin group (P<0.01). The histological score of the Cur@MSN group was lower than that of the degeneration group and the curcumin group (P<0.01). Conclusions Cur@MSN can delay the degeneration process of rat coccygeal intervertebral disc, and has certain repair and treatment effects on its degenerated intervertebral disc. Among them, curcumin can delay the degeneration of intervertebral disc by inhibiting inflammation, and the loading of MSN is helpful for curcumin to exert its biological effects.
Multidrug resistance (MDR) remains the major obstacle to the success of clinical cancer chemotherapy. P-glycoprotein (P-gp), encoded by the MDR1, is an important part with complex mechanisms associated with the MDR. In order to overcome the MDR of tumors, we in the present experimental design incorporated small interfering RNA (siRNA) targeting MDR1 gene and anticancer drug paclitaxel (PTX) into the solid lipid nanoparticles (SLNs) to achieve the combinational therapeutic effects of genetherapy and chemotherapy. In this study, siRNA-PTX-SLNs were successfully prepared. The cytotoxicity of blank SLNs and siRNA-PTX-SLNs in MCF-7 cells and MCF-7/ADR cells were detected by MTT; and the uptake efficiency of PTX in MCF-7/ADR cells were detected via HPLC method; quantitative real-time PCR and flow cytometry were performed to investigate the silencing effect of siRNA-PTX-SLNs on MDR1 gene in MCF-7/ADR cells. The results showed that PTX loaded SLNs could significantly inhibit the growth of tumor cells, and more importantly, the MDR tumor cells treated with siRNA-PTX-SLNs showed the lowest viability. HPLC study showed that SLNs could enhance the cellular uptake for PTX. Meanwhile, siRNA delivered by SLNs significantly decreased the P-gp expression in MDR tumor cells, thus increased the cellular accumulation of rhodamine123 as a P-gp substrate. In conclusion, the MDR1 gene could be silenced by siRNA-PTX-SLNs, which could promote the growth inhibition efficiency of PTX on tumor cells, leading to synergetic effect on MDR tumor therapy.
Objective To evaluate the feasibility of sentinel lymph node (SLN) mapping after 99Tcm sulfur colloid (99Tcm-sc) and carbon nanoparticles injection in patients with colon cancer. Methods Forty patients with colon cancer underwent complete mesocolic excision between August 2015 and July 2016 at Qingdao Central Hospital were considered for prospective inclusion. Before resection, SLN mapping was performed with injection of 99Tcm-sc and carbon nanopar-ticles, then all dissected lymph nodes were detected by pathological examination. Results A total of 660 cases of lymph nodes were found in the 40 patients (average of 16.5 cases per patient). Of them, 88 nodes (average of 2.2 cases per patient) were identified as SLN in 36 of 40 patients, with a successful detection rate of 90.0% (36/40). The diagnostic accuracy, sensitivity, and false-negative rate were 87.5% (35/40), 96.2% (25/26), and 3.8% (1/26) respectively. Conclusion 99Tcm-sc and carbon nanoparticles suspension injection for mapping SLN is a feasiblely diagnostic method for predicting local lymph node metastasis in the patient with colon cancer.
In order to solve the problem of high cytotoxicity in vitro of nano-silver antibacterial gel, and the problem of large nano-silver particle size and size distribution, this study prepared nano-silver antibacterial gel with better biocompatibility and good antibacterial effect by using physical cross-linking method and using poloxamer as dispersant when prepared nano-silver. In this study, nano-silver was prepared by photo-initiator method and by adding poloxamer as a dispersant, and then UV-visible absorption spectrum test and scanning electron microscopy (SEM) test were carried out using prepared nano-silver mixture and particles after drying respectively. The gel was prepared through adjusting its pH value by using sodium bicarbonate, and then pH value test, SEM test for cross-section of gel, swelling ratio test, viscosity test, inhibition zone test and in vitro cytotoxicity test were carried out. The test results showed that the maximum absorption wavelength of prepared nano-silver, using poloxamer as dispersant and ultra-pure water as solvent, was 414 nm, and the average nano-silver size was about 60 nm. The prepared nano-silver using poloxamer as dispersant had smaller particle diameter and narrower particle size distribution than those using PVP as dispersant. Similarly, the prepared nano-silver using ultra-pure water as solvent also had smaller particle diameter and narrower particle size distribution than those using distilled water as solvent. The pH value of the prepared gel was between 5.8~6.1. The dried gel section had many holes. The water absorption of gel was fine and the viscosity of gel was fit to coat on the gauze. In addition, the prepared gel with nano-silver had greater ability to inhibit Escherichia coli and Staphyloccocus aureus at the concentrations of 24, 18 and 12 μg/mL. And the biocompatibility of the prepared gel with nano-silver was good when the concentration below 24 μg/mL. Based on the above features, the nano-silver antibacterial gel could be used in the treatment of burn or other wounds.
As drug carriers, magnetic nanoparticles can specifically bind to tumors and have the potential for targeted therapy. It is of great significance to explore non-invasive imaging methods that can detect the distribution of magnetic nanoparticles. Based on the mechanism that magnetic nanoparticles can generate ultrasonic waves through the pulsed magnetic field excitation, the sound pressure wave equation containing the concentration information of magnetic nanoparticles was derived. Using the finite element method and the analytical solution, the consistent transient pulsed magnetic field was obtained. A three-dimensional simulation model was constructed for the coupling calculation of electromagnetic field and sound field. The simulation results verified that the sound pressure waveform at the detection point reflected the position of magnetic nanoparticles in biological tissue. Using the sound pressure data detected by the ultrasonic transducer, the B-scan imaging of the magnetic nanoparticles was achieved. The maximum error of the target area position was 1.56%, and the magnetic nanoparticles regions with different concentrations were distinguished by comparing the amplitude of the boundary signals in the image. Studies in this paper indicate that B-scan imaging can quickly and accurately obtain the dimensional and positional information of the target region and is expected to be used for the detection of magnetic nanoparticles in targeted therapy.
Cobalt or chromium alloys are the most common clinical materials of prosthesis and there have been some investigators at home and abroad have done related researches about the genotoxic effects of cobalt and chromium ions and nanoparticles. People have certain understanding about the mechanism of production of ions as well as their influence on cells. However, chromium or cobalt nanoparticles genotoxicity related research is still in its preliminary stage. In each stage, the mechanisms, from creating of the particles, through entering cells, until finally causing genotoxic, are still contained many problems to be solved. This article reviews the research progress in mechanisms of production and genotoxic effects of cobalt, chromium ions and nanoparticles.
ObjectiveTo explore the effect of hydroxyapatite nanoparticle (nHAP) on hepatocellular carcinoma (HCC) and its mechanisms. MethodsThe literatures about the effect of nHAP on HCC were reviewed and summarized. ResultsAs a new nanoparticle, nHAP could suppress the DNA synthesis and subsequent division and proliferation of HCC cells through the inhibition of proliferating cell nuclear antigen (PCNA) and telomerase gene expression and increase of intracellular Ca2+. Moreover, nHAP was able to suppress the differentiation and metastases of HCC cells through the effect on the expressions of Paxillin and P130cas and the decrease of expressions of multiple drug resistance gene protein, microvessel density, and vascular endothelial growth factor. Finally, nHAP induced the apoptosis of HCC tumor cells by the regulation of bcl-2 and bax protein expressions. The combined use of nHAP and chemoembolization drugs could enhance the efficacy, prolong drug duration and reduce toxicity. ConclusionnHAP can inhibit the division, proliferation, differentiation, and metastases, and promote the apoptosis of HCC cells and combined use with chemoembolization drugs can enhance the efficacy and reduce toxicity.
We prepared silver nanoparticles/polyethyleneimine-reduction graphene oxide (AgNP/rGO-PEI) composite materials, and evaluated their quality performance in our center. Firstly, we prepared AgNP/rGO-PEI, and then analysed its stability, antibacterial activity, and cellular toxicity by comparing the AgNP/rGO-PEI with the silver nanoparticles (PVP/AgNP) modified by polyvinylpyrrolidone. We found in the study that silver nanoparticles (AgNP) distributed relatively uniformly in AgNP/rGO-PEI surface, silver nanoparticles mass fraction was 4.5%, and particle size was 6-13 nm. In dark or in low illumination light intensity of 3 000 lx meter environment (lux) for 10 days, PVP/AgNP aggregation was more obvious, but the AgNP/rGO-PEI had good dispersibility and its aggregation was not obvious; AgNP/rGO-PEI had a more excellent antibacterial activity, biological compatibility and relatively low biological toxicity. It was concluded that AgNP/rGO-PEI composite materials had reliable quality and good performance, and would have broad application prospects in the future.
Objective To observe the inhibitory characteristics of silver nanoparticles (AgNP) on bacterial biofilms and investigate their inhibitory effect on biofilm formation on three common orthopedic biomaterials. Methods The minimal inhibitory concentration (MIC) and minimal biofilm inhibitory concentration (MBIC) of AgNP were determined by microplate dilution assay. Biofilms of Staphylococcus aureus (ATCC 25923) were cultured on three orthopedic biomaterials (titanium alloy, titanium oxide, and stainless steel) and intervened with AgNP at concentrations of 32, 16, 8, 4, 2 and 0 μg/mL to determine the MBICs on the three materials. The effects of AgNP on biofilm formation were analyzed by scanning electron microscopy and measuring optical density. Results The MIC and MBIC of AgNP in the microplate assay were both 16 µg/mL. The MBICs of AgNP on biofilm formation in titanium oxide, titanium alloy, and stainless steel were 16 μg/mL, 32 μg/mL, and 32 μg/mL, respectively. Among the three materials, the lowest optical density was observed on titanium oxide, while the highest was on titanium alloy. Conclusions AgNP has strong antibacterial biofilm characteristics and can prevent the formation of Staphylococcus aureus biofilm in vitro. Biofilm formation is most pronounced on titanium alloy, least on titanium oxide, and intermediate on stainless steel.
Due to the good tumor-targeting and excellent biocompatibility, the drug-loading nanoparticles (NPs) has been widely applied in the diagnosis and treatment of cancer. However, after the NPs are recognized and internalized by cancer cells, the effects of NPs on cell migration behavior were unclear. In the present study, the self-assembly techniques (SAMs) was used to modify gold (Au) nanoparticles (Au NPs) with different chemical functional groups (CH3, OH, COOH and NH2) as model NPs. The dispersion of these groups in solution and the distribution in cells were studied by transmission electron microscope (TEM), respectively, and the proliferation was examined by MTT assay in vitro. The wound-healing and the Transwell assay were used to examine the effect of internalized Au-NPs on HepG2 cells migration. The results showed that different Au-NPs mainly distributed at the edge of the vesicle membrane and the gap between cells. The Au-NPs resulted in decreased cell viability in a concentration-depended manner. In addition, the results of wound-healing and Transwells assay indicated that the internalization of the NH2-NPs and OH-NPs would inhibit cell migration compared with those in the control group.