Near-infrared laser light mediated cancer therapy by photothermal effect of Fe3O4 magnetic nanoparticles.

The photothermal effect of Fe3O4 magnetic nanoparticles is investigated for cancer therapy both in vitro and in vivo experiments. Heat is found to be rapidly generated by red and near-infrared (NIR) range laser irradiation of Fe3O4 nanoparticles with spherical, hexagonal and wire-like shapes. These Fe3O4 nanoparticles are coated with carboxyl-terminated poly (ethylene glycol)-phospholipid for enhanced dispersion in water. The surface-functionalized Fe3O4 nanoparticles can be taken up by esophageal cancer cells and do not obviously affect the cell structure and viability. Upon irradiation at 808 nm however, the esophageal cancer cell viability is effectively suppressed, and the cellular organelles are obviously damaged when incubated with the NIR laser activated Fe3O4 nanoparticles. Mouse esophageal tumor growth was found to be significantly inhibited by the photothermal effect of Fe3O4 nanoparticles, resulting in effective tumor reduction. A morphological examination revealed that after a photothermal therapy, the tumor tissue structure exhibited discontinuation, the cells were significantly shriveled and some cells have finally disintegrated.

Laser light triggered-activated carbon nanosystem for cancer therapy.

Among carbon-based nanomaterials, activated carbon (AC) may be an ideal candidate as a carrier for tumor therapeutic agents. Here we found a new property of nanoscale activated carbon (NAC) with narrow size distribution, namely the rapid conversion of light to thermal energy both in vitro and in vivo. An aqueous suspension of 200 µL of NAC (1 mg/mL) exhibited a rapid temperature increase of more than 35 °C after irradiation for 20 min with a 655-nm laser; this was within the temperature range for effective tumor treatment. We demonstrated that lung cancer cells (H-1299) incubated with bamboo nano-AC (BNAC) were killed with high efficiency after laser irradiation. In addition, mouse tumors with sizes smaller than the laser spot that had been injected with BNAC disappeared after irradiation. For tumors larger than the laser spot area, the incorporation of the photosensitizer ZnPc obviously increased the tumor growth inhibition efficiency of BNAC. BNAC-ZnPc was found to exhibit a synergistic effect when photothermal and photodynamic therapies were administered in combination. These results indicated that NAC can be used for high efficiency cancer phototherapy.

Examining the interactome of huperzine A by magnetic biopanning.

Huperzine A is a bioactive compound derived from traditional Chinese medicine plant Qian Ceng Ta (Huperzia serrata), and was found to have multiple neuroprotective effects. In addition to being a potent acetylcholinesterase inhibitor, it was thought to act through other mechanisms such as antioxidation, antiapoptosis, etc. However, the molecular targets involved with these mechanisms were not identified. In this study, we attempted to exam the interactome of Huperzine A using a cDNA phage display library and also mammalian brain tissue extracts. The drugs were chemically linked on the surface of magnetic particles and the interactive phages or proteins were collected and analyzed. Among the various cDNA expressing phages selected, one was identified to encode the mitochondria NADH dehydrogenase subunit 1. Specific bindings between the drug and the target phages and target proteins were confirmed. Another enriched phage clone was identified as mitochondria ATP synthase, which was also panned out from the proteome of mouse brain tissue lysate. These data indicated the possible involvement of mitochondrial respiratory chain matrix enzymes in Huperzine A's pharmacological effects. Such involvement had been suggested by previous studies based on enzyme activity changes. Our data supported the new mechanism. Overall we demonstrated the feasibility of using magnetic biopanning as a simple and viable method for investigating the complex molecular mechanisms of bioactive molecules.

Alleviation of the acute doxorubicin-induced cardiotoxicity by Lycium barbarum polysaccharides through the suppression of oxidative stress.

The present study aims to investigate whether Lycium barbarum polysaccharides (LBP) could protect against acute doxorubicin (DOX)-induced cardiotoxicity. Rats received daily treatment of either distilled water (4 ml/kg) or LBP (200mg/kg) for 10 days and then followed by an intravenous injection at day 7 of either saline (10 ml/kg) or DOX (10 mg/kg). DOX induced significantly myocardial damage in rats, which were characterized as conduction abnormalities, decreased heart-to-body weight ratio, increased serum CK, and myofibrillar disarrangement. DOX treatment also increased MDA and decreased SOD and GSH-Px activity in cardiac tissues. Pretreatment with LBP significantly reduced DOX-induced oxidative injury in cardiac tissue, suggesting by the fact that LBP significantly attenuated DOX-induced cardiac myofibrillar disarrangement and LBP was effective in decreasing the levels of serum CK and thus improving conduction abnormalities caused by DOX. LBP treatment significantly increased SOD and GSH-Px activity and decreased the MDA level of heart tissues damaged by DOX exposure in rats. Furthermore, the cytotoxic study showed that LBP protect against cytotoxicity of DOX in cardiac myoblasts H9c2 but dose not attenuate the anti-tumor activity of DOX. In summary, our evidence indicates that LBP elicited a typical protective effect on DOX-induced acute cardiotoxicity via suppressing oxidative stress.