Artificial cell containing superoxide dismutase--selection of folding aids for stabilisation of SOD

Shielding of the geomagnetic field reduces hydrogen peroxide production in human neuroblastoma cell and inhibits the activity of CuZn superoxide dismutase

Accumulative evidence has shown the adverse effects of a geomagnetic field shielded condition, so called a hypomagnetic field (HMF), on the metabolic processes and oxidative stress in animals and cells. However, the underlying mechanism remains unclear. In this study, we evaluate the role of HMF on the regulation of cellular reactive oxygen species (ROS) in human neuroblastoma SH-SY5Y cells. We found that HMF exposure led to ROS decrease, and that restoring the decrease by additional H2O2 rescued the HMF-enhanced cell proliferation. The measurements on ROS related indexes, including total anti-oxidant capacity, H2O2 and superoxide anion levels, and superoxide dismutase (SOD) activity and expression, indicated that the HMF reduced H2O2 production and inhibited the activity of CuZn-SOD. Moreover, the HMF accelerated the denaturation of CuZn-SOD as well as enhanced aggregation of CuZn-SOD protein, in vitro. Our findings indicate that CuZn-SOD is able to response to the HMF stress and suggest it a mediator of the HMF effect.

Surface modification of polymeric biomaterials: Utilization of cyclodextrins for blood compatibility improvement

A novel modified polymeric biomaterial surface using cyclodextrins (CDs) for improved blood compatibility was studied. Plasticized poly(vinyl chloride) (PVC-P) was selected for modification and polyethylene was used as a reference material. The modification was achieved by polymer blending. Fibrinogen and albumin adsorption were utilized as indices for the assessment of the blood compatibility. Surface characterization confirmed that CDs were able to accumulate at the PVC surface and alter the surface properties. The combination of other hydrophilic polymers such as poly(ethylene oxide) (PEO) and PEO/poly(propylene oxide) (PPO) copolymers, such as Pluronic F68 (F68), with CDs were also investigated. These modified materials have a remarkable protein-resistant surface. The combination of B-cyclodextrin (B-CD)/PEO and B-CD/F68 in certain feeding ratio are synergistic in producing enhanced blood compatibility.