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.
Medical magnetic nanoparticles are nano-medical materials with superparamagnetism, which can be collected in the tumor tissue through blood circulation, and magnetic particle imaging technology can be used to visualize the concentration of magnetic nanoparticles in the living body to achieve the purpose of tumor imaging. Based on the nonlinear magnetization characteristics of magnetic particles and the frequency characteristics of their magnetization, a differential detection method for the third harmonic of magnetic particle detection signals is proposed. It was modeled and analyzed, to study the nonlinear magnetization response characteristics of magnetic particles under alternating field, and the spectral characteristics of magnetic particle signals. At the same time, the relationship between each harmonic and the amount of medical magnetic nanoparticle samples was studied. On this basis, a signal detection experimental system was built to analyze the spectral characteristics and power spectral density of the detected signal, and to study the relationship between the signal and the excitation frequency. The signal detection experiment was carried out by the above method. The experimental results showed that under the alternating excitation field, the medical magnetic nanoparticles would generate a spike signal higher than the background sensing signal, and the magnetic particle signal existed in the odd harmonics of the detected signal spectrum. And the spectral energy was concentrated at the third harmonic, that is, the third harmonic magnetic particle signal detection that meets the medical detection requirement could be realized. In addition, the relationship between each harmonic and the particle sample volume had a positive growth relationship, and the detected medical magnetic nanoparticle sample volume could be determined according to the relationship. At the same time, the selection of the excitation frequency was limited by the sensitivity of the system, and the detection peak of the third harmonic of the detection signal was reached at the excitation frequency of 1 kHz. It provides theoretical and technical support for the detection of medical magnetic nanoparticle imaging signals in magnetic particle imaging research.
ObjectiveTo investigate the value of carbon nanoparticle adopted in reoperation for thyroid cancer recurrence.
MethodsFrom July to November of 2015, patients diagnosed with thyroid cancer recurrence in department of Thyroid & Parathyroid surgery, West China Hospital, Sichuan University were enrolled in the research. All enrollment patients underwent carbon nanoparticles location guided by ultrasonography before reoperation. Relative data about surgery and location were analyzed retrospectively.
ResultsTwenty-two patients were enrolled in the research. Mean operation time was (60.45±12.91) minutes. During surgery, a total of 405 (average 18.4) lymph nodes were harvested, and the staining rate was 71.9% (291/405). The pathological examination showed that there was a significant difference in the positive rate between carbon nanoparticles stained lymph nodes (45.0%, 131/291) and non-stained lymph nodes (5.3%, 6/114), P < 0.001. In addition, the positive rate in non-targeted stained lymph nodes was 30.2% (62/205). By contrast, it was 5.3% (6/114) in non-targeted non-stained lymph nodes. The difference showed significant significance (P < 0.001).
ConclusionsAdoption of carbon nanoparticles in reoperation for thyroid cancer, which improves efficiency of dissection for the non-palpable lymph nodes metastasis, is worth generalizing in clinical practice.
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.
Objective
To explore the effect of carbon nanoparticles dyeing on axillary lymph node dissection in modified radical mastectomy for breast cancer.
Methods
Eighty-eight patients with breast cancer who received modified radical mastectomy in Mianyang Central Hospital between Mar. 2012 and May. 2013 were recruited in the study, and they were equally divided into areola group and peripheral tumor group. After induction of anesthesia before operation, carbon nanoparticles were injected around the areolar in the areola group, and carbon nanoparticles were injected around the tumor in the peripheral tumor group. The number of dissected lymph nodes(be dyed or not be dyed), metastatic lymph nodes, and black dyed lymph nodes, as well as value of operation related indexes were recorded and compared.
Results
In the areola group, lymph nodes were detected in 1 453, in which 1 396 lymph nodes were stained black(96.1%); the average number of dissected lymph nodes were 33.0±7.1 per case; and 19 patients (43.2%, in total of 220 metastatic lymph nodes) of them were suffered from lymph node metastasis with the average number of metastatic lymph nodes of 5±2 per case. in addition, in the areola group, operative time were(122.1±10.2) min, blood loss were(83.8±10.1) mL, postoperative hospital stay were(7±1) d, and postoperative complications occurred in 3 patients. In the peripheral tumor group, lymph nodes were detected in 909, in which 594 lymph nodes were stained black (65.3%); the average number of dissected lymph nodes were 20.7±3.2 per case; 20 patients (45.5%, in total of 88 metastatic lymph nodes) of them were suffered from lymph nodes metastasis, with the average number of metastatic lymph nodes of 2±1 per case. In addition, in the peripheral tumor group, operative time were (121.6±11.4) min, blood loss were (84.2±11.3) mL, postoperative hospital stay were (7±2) d, postoperative complications occurred in 3 patients. The black staining rate of lymph nodes, the number of lymph nodes retrieved, and the number of metastatic lymph nodes in areola group were significantly higher than those of peripheral tumor group(P < 0.01). Operative time, blood loss, postoperative hospital stay, and postoperative complication rate did not significantly differ between the 2 groups (P > 0.05).
Conclusion
The dyeing effect of carbon nanoparticles suspension, which was injected at areola area after induction of anesthesia, is better than that of injected around the tumor, without increasing the incidence of complication.
Abstract： Surgery is an effective therapy for non-small cell lung cancer (NSCLC). The standard operation includes lobectomy and systematic dissection of lymph nodes. However, postoperative tumor recurrence is common even among incipient patients due to incomplete dissection of lymph nodes and micrometastasis of lymph nodes. Injecting a carbon nanoparticles suspension is a new technique aimed at preventing this recurrence. The carbon nanoparticles carry lymph node tracers that help surgeons locate lymph nodes in order to clean them thoroughly. The tracers also target the lymph nodes for chemotherapy, thus killing residual tumor cells intraoperatively to avoid postoperative cancer recurrence. Carbon nanoparticles suspension injection is already widely and successfully used in surgery for gastrointestinal and mammary gland tumors, and is being tested for effectiveness in NSCLC patients. Some studies have indicated that carbon nanoparticles suspension injection is effective in NSCLC patients and improves their prognoses. We reviewed the features, application methods, and clinical applications of studies of carbon nanoparticles suspension injection for NSCLC.
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.
Macrophages are important immune effector cells with significant plasticity and heterogeneity in the body immune system, and play an important role in normal physiological conditions and in the process of inflammation. It has been found that macrophage polarization involves a variety of cytokines and is a key link in immune regulation. Targeting macrophages by nanoparticles has a certain impact on the occurrence and development of a variety of diseases. Due to its characteristics, iron oxide nanoparticles have been used as the medium and carrier for cancer diagnosis and treatment, making full use of the special microenvironment of tumors to actively or passively aggregate drugs in tumor tissues, which has a good application prospect. However, the specific regulatory mechanism of reprogramming macrophages using iron oxide nanoparticles remains to be further explored. In this paper, the classification, polarization effect and metabolic mechanism of macrophages were firstly described. Secondly, the application of iron oxide nanoparticles and the induction of macrophage reprogramming were reviewed. Finally, the research prospect and difficulties and challenges of iron oxide nanoparticles were discussed to provide basic data and theoretical support for further research on the mechanism of the polarization effect of nanoparticles on macrophages.
Objective To assess the applied significance of carbon nanoparticles in central compartment lymph node dissection in treatment of cN0 papillary thyroid carcinoma. Methods Sixty-eight patients with cN0 papillary thyroid carcinoma who were treated in Tongji Hospital of Tongji Medical College from May. to Oct. in 2012 were randomly allocated to the control group （n=32） and the carbon nanoparticles trace group （tracer group， n=36）， receiving non-carbon nanoparticles trace and carbon nanoparticles trace respectively. All patients were received total resection of thyroid plus the affected side and （or） contralateral side central compartment lymph node dissection. The lymph node-related indexes（including number of dissected lymph node at Ⅵarea and lymph node metastasis rate at Ⅵarea） and operative indexs （including operation time， blood loss， drainage time， complication， and hospital stay） were collected and compared between the 2 groups. Results There were 205 and 324 dissected lymph node at central compartment in control group and tracer group respectively. The results of postoperative pathology showed that the number of lymph node in central compartment of the tracer group was much more than those of control group （8.99±2.24 vs. 6.41±1.56， P＜0.001）. The metastasis rate of central compartment lymph node were 40.6% （13/32） in control group and 47.2% （17/36） in tracer group， but there was no significant difference between the 2 groups （P=0.762）. But in medial area of laryngeal recurrent nerve， the metastasis rate in the tracer group （38.9%， 14/36） was much higher than those of control group （12.5%， 4/32）， P=0.029. There were no significant differences in the operation time， blood loss， drainage time， hospital stay， and complication incidence such as bleeding， temporary hypocalcemia， and injury of superior laryngeal nerve between 2 groups （P＞0.05）. All the patients in 2 groups had followed-up for 6 months without death， recurrence， and metastasis.Conclusions The lymphatic tracer technique of carbon nanoparticles may improve the number of dissected lymph nodes in central region of cN0 papillary thyroid carcinoma， without increasing （or prolonging） operation time， intraoperative blood loss， and postoperative hospital stay， and can accurately represent the metastasis of lymph node， thus to make the staging of the tumor accurately and guide postoperative treatment.
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.
