This study was to develop a new method for detecting circulating tumor cells (CTCs) with high sensitivity and specificity, therefore to detect the colorectal cancer as early as possible for improving the detection rate of the disease. To this end, we prepared some micro-column structure microchips modified with graphite oxide-streptavidin (GO-SA) on the surface of microchips, further coupled with a broad-spectrum primary antibody (antibody1, Ab₁), anti-epithelial cell adhesion molecule (anti-EpCAM) monoclonal antibody to capture CTCs. Besides, carboxylated multi-walled carbon nanotubes (MWCNTs-COOH) were coupled with colorectal cancer related antibody as specific antibody 2 (Ab₂) to prepare complex. The sandwich structure consisting of Ab₁-CTCs-Ab₂ was constructed by the microchip for capturing CTCs. And the electrochemical workstation was used to detect and verify its high sensitivity and specificity. Results showed that the combination of immunosensor and micro-nano technology has greatly improved the detection sensitivity and specificity of the immunosensor. And we also verified the feasibility of the immunosensor for clinical blood sample detection, and successfully recognitized detection and quantization of CTCs in peripheral blood of colorectal cancer patients by this immunosensor. In conclusion, the super sandwich immunosensor based on micro-nano technology provides a new way for the detection of CTCs, which has potential application value in clinical diagnosis and real-time monitoring of disease.
Humans ; Nanotubes, Carbon/chemistry* ; Neoplastic Cells, Circulating/pathology* ; Biosensing Techniques ; Immunoassay/methods* ; Antibodies ; Colorectal Neoplasms/diagnosis* ; Electrochemical Techniques/methods* ; Gold/chemistry*

Carbon nanotube (CNT) composite materials are very attractive for use in neural tissue engineering and biosensor coatings. CNT scaffolds are excellent mimics of extracellular matrix due to their hydrophilicity, viscosity, and biocompatibility. CNTs can also impart conductivity to other insulating materials, improve mechanical stability, guide neuronal cell behavior, and trigger axon regeneration. The performance of chitosan (CS)/polyethylene glycol (PEG) composite scaffolds could be optimized by introducing multi-walled CNTs (MWCNTs). CS/PEG/CNT composite scaffolds with CNT content of 1%, 3%, and 5% (1%=0.01 g/mL) were prepared by freeze-drying. Their physical and chemical properties and biocompatibility were evaluated. Scanning electron microscopy (SEM) showed that the composite scaffolds had a highly connected porous structure. Transmission electron microscope (TEM) and Raman spectroscopy proved that the CNTs were well dispersed in the CS/PEG matrix and combined with the CS/PEG nanofiber bundles. MWCNTs enhanced the elastic modulus of the scaffold. The porosity of the scaffolds ranged from 83% to 96%. They reached a stable water swelling state within 24 h, and swelling decreased with increasing MWCNT concentration. The electrical conductivity and cell adhesion rate of the scaffolds increased with increasing MWCNT content. Immunofluorescence showed that rat pheochromocytoma (PC12) cells grown in the scaffolds had characteristics similar to nerve cells. We measured changes in the expression of nerve cell markers by quantitative real-time polymerase chain reaction (qRT-PCR), and found that PC12 cells cultured in the scaffolds expressed growth-associated protein 43 (GAP43), nerve growth factor receptor (NGFR), and class III β‍-tubulin (TUBB3) proteins. Preliminary research showed that the prepared CS/PEG/CNT scaffold has good biocompatibility and can be further applied to neural tissue engineering research.
Animals ; Axons ; Biocompatible Materials/chemistry* ; Chitosan/chemistry* ; Nanotubes, Carbon/chemistry* ; Nerve Regeneration ; Polyethylene Glycols ; Porosity ; Rats ; Tissue Engineering/methods* ; Tissue Scaffolds/chemistry*

Carbon nanotubes possess excellent mechanical and electrical properties and demonstrate broad application prospects in medical fields. Carbon nanotubes are composed of inorganic materials, natural biodegradable polymer or synthetic biodegradable polymer. The composite bone tissue engineering scaffolds are constructed by particle-hole method, lyophilization, microsphere aggregation method, electrostatic spinning or three-dimensional printing. Composite scaffolds overcome the shortcomings of single material and have good biocompatibility, osteoconduction and osteoinduction. With the study of surface chemistry, toxicology, and biocompatibility, a degradable "human-friendly" carbon nanotubes composite bone tissue scaffold will be available; and under the drive of new fabrication techniques, the clinical application of carbon nanotubes composite bone tissue engineering scaffolds will be better developed.
Biocompatible Materials ; chemistry ; Bone Development ; Humans ; Microspheres ; Nanotubes, Carbon ; chemistry ; Polymers ; chemistry ; Printing, Three-Dimensional ; Tissue Engineering ; Tissue Scaffolds ; chemistry

In this paper, the new carbon nanotube modified glassy carbon electrode (F-CNTs/GCE) was prepared to establish a new method for studying the molecular interaction mechanism between baicalin metal complexes (BMC) and bovine serum album (BSA), and the principle of this method was discussed deeply. Under the physiological condition, the thermodynamics and kinetics properties of interaction between BMC and BSA were studied by cyclic voltammetry (CV) to inference their molecular effective mechanism. The results show that the presence of F-CNTs can accelerate the electron transfer, and better response signal was showed in the BMC/BMC-BSA system. The detection of interaction of BMC-BSA used new method show that BMC-BSA generates stable thermodynamically non-covalent compounds, and the obtained average binding sites of BMC-BSA were 1.7; the number of electron transfer in BMC/BMC-BSA reaction process was 2, and non electroactive supramolecular compounds of BMC-BSA were generated by this interacting reaction. The relevant research work provides a new way to study the molecular mechanism for the interaction of drugs with protein, and with a certain reference value for discussion on the non covalent interactions.
Animals ; Cattle ; Coordination Complexes ; chemistry ; Electrodes ; Flavonoids ; chemistry ; Kinetics ; Nanotubes, Carbon ; Serum Albumin, Bovine ; chemistry ; Thermodynamics

Malignant cancer is the leading cause of death in man, exceeding cerebrovascular disease and heart disease. More than half of the total mortality due to malignant cancer is from lung, liver, intestinal and gastric cancer. Chemotherapy is one of the effective treatments for cancer. However, the great majority of Western anticancer medicines have considerable side effects. Herbal medicines offer many more advantages than synthesized compounds because they are made from purely natural compounds and have less adverse effects. However, the single administration methods used as standard in herbal medicine, and deficient drug targeting, severely limit their anticancer activity. Single-walled carbon nanotubes (SWNTs) can be used as drug carriers. They have been modified to form Chinese anticancer medicine-SWNT compounds which can specifically target tumors, thereby significantly increasing the therapeutic effectiveness of these medicines. Water-soluble SWNTs have high stability. As a drug carrier, SWNTs functional modification of the anticancer medicine may improve the targeting and killing of tumor cells. SWNTs have been attached to the Chinese antitumor medicines paclitaxel and plumbagin and have achieved excellent therapeutic effects. Furthermore, choosing the best administration methods such as internal iliac arterial infusion, intravesical infusion and embedment of a hypodermic chemotherapeutic pump, may also improve the anticancer effects of Chinese medicine.
Antineoplastic Agents ; pharmacology ; therapeutic use ; Cell Death ; drug effects ; Drug Carriers ; Drug Delivery Systems ; Drugs, Chinese Herbal ; therapeutic use ; Feasibility Studies ; Humans ; Nanotubes, Carbon ; chemistry ; Neoplasms ; drug therapy ; pathology

Nanotubes, Carbon ; adverse effects ; chemistry

In this study, the adsorption behavior of epirubicin hydrochloride (EPI) on carboxylated single-walled carbon nanotubes (c-SWNTs) obtained by mixture acid treatment was investigated. The results indicated that the dispersion of c-SWNTs in water was obviously improved. The absorption of EPI on c-SWNTs came to equilibrium after 240 min and could be explained by pseudo-second-order model. Moreover, there were heterogeneous distribution of active sites onto c-SWNTs surface and the Freundlich isotherm model was better fit to describe the absorption precess of EPI on c-SWNTs. The absorption capacity of EPI on c-SWNTs increased obviously with the increasing pH and decreasing temperature. Compared with multi-walled carbon nanotubes, carboxylated multi-walled carbon nanotubes, SWNTs, c-SWNTs possessed higher absorption capacity for EPI. The controlled, targeted and sustained release of EPI from c-SWNTs-EPI could be instructive for the development of nano-carrier.
Adsorption ; Antibiotics, Antineoplastic ; chemistry ; Carboxylic Acids ; chemistry ; Drug Carriers ; Epirubicin ; chemistry ; Nanotubes, Carbon ; chemistry

We examined the biocompatibility and the safety of a-calcium sulfate hemihydrate (CSH)/multi-walled carbon nanotube (MWCNT) composites for bone reconstruction application. The biocompatibility of the CSH/MWCNT composites was evaluated by the measures which taking L929 fibroblast cells cultured in the extracted liquid of the composite soaking solution and putting bone marrow stromal cells planted on the composite pellets in vitro, respectively. The cell proliferation was evaluated by MTT test and further observed using an inverted optical microscope and a scanning electric microscope. The toxicity of the composites was evaluated by acute and subacute systemic toxicity test. Long-term muscle and bone implantation in vivo tests were also conducted. L929 fibroblast cells grew well in the extracted liquid, as well as bone marrow stromal cells that could adhere on the surface of sample pellets and proliferated rapidly. MTT test showed that there were no significant differences between the experimental and control groups (P > 0.05). In vivo test manifested that the composites were no toxicity, no irritation to skin and good for bone defect reconstruction. It was proved that a-calcium sulfate hemihydrate (CSH)/multi-walled carbon nanotube (MWCNT) composites exhibited excellent biocompatibility for the potential application in bone tissue engineering.
Animals ; Biocompatible Materials ; chemistry ; Bone Marrow Cells ; cytology ; Bone Substitutes ; chemical synthesis ; chemistry ; Calcium Sulfate ; chemistry ; Cell Line ; Cell Proliferation ; Fibroblasts ; cytology ; Materials Testing ; Nanotubes, Carbon ; chemistry ; Rabbits ; Stromal Cells ; cytology ; Tissue Engineering ; methods ; Toxicity Tests

With the emergence of avian flu, influence A virus and other diseases, the development of rapid, real-time, label-free biological sensors has become increasingly significant at the early detection and clinical diagnoses of various diseases. Single-walled carbon nanotubes (SWNTs) have unique one-dimensional structure, special electrical properties, good biocompatibility and size compatibility, so that the SWNTs have great potential uses in the biosensor fields due to these advantages. This article reviews recent examples of carbon nanotubes field-effect transistor (CNTFET) as a label-free biosensors for detecting a variety of biological macromolecules, such as protein, enzyme, DNA, cancer, virus, carbohydrate and so on.
Animals ; Biosensing Techniques ; instrumentation ; trends ; DNA ; chemistry ; Humans ; Nanotubes, Carbon ; chemistry ; Proteins ; analysis ; Transistors, Electronic

OBJECTIVETo investigate in vitro cytotoxicity and oxidative stress response induced by multiwalled carbon nanotubes (MWCNTs).

METHODSCultured macrophages (murine RAW264.7 cells) and alveolar epithelium cells type II (human A549 lung cells) were exposed to the blank control, DNA salt control, and the MWCNTs suspensions at 2.5, 10, 25, and 100 μg/mL for 24 h. Each treatment was evaluated by cell viability, cytotoxicity and oxidative stress.

RESULTSOverall, both cell lines had similar patterns in response to the cytotoxicity and oxidative stress of MWCNTs. DNA salt treatment showed no change compared to the blank control. In both cell lines, significant changes at the doses of 25 and 100 μg/mL treatments were found in cell viabilities, cytotoxicity, and oxidative stress indexes. The reactive oxygen species (ROS) generation was also found to be significantly higher at the dose of 10 μg/mL treatment, whereas no change was seen in most of the indexes. The ROS generation in both cell lines went up in minutes, reached the climax within an hour and faded down after several hours.

CONCLUSIONExposure to MWCNTs resulted in a dose-dependent cytotoxicity in cultured RAW264.7 cells and A549 cells, that was closely correlated to the increased oxidative stress.

Animals ; Cell Culture Techniques ; Cell Line ; Cell Survival ; drug effects ; Dose-Response Relationship, Drug ; Humans ; Lung ; drug effects ; enzymology ; metabolism ; pathology ; Macrophages, Alveolar ; drug effects ; enzymology ; metabolism ; pathology ; Mice ; Microscopy, Electron, Scanning ; Microscopy, Electron, Transmission ; Microscopy, Fluorescence ; Nanotubes, Carbon ; chemistry ; toxicity ; Oxidative Stress ; drug effects ; Reactive Oxygen Species ; metabolism ; Surface Properties