Ultra-fast stem cell labelling using cationised magnetoferritin

Magnetic cell labelling with superparamagnetic iron oxide nanoparticles (SPIONs) facilitates many important biotechnological applications, such as cell imaging and remote manipulation. However, to achieve adequate cellular loading of SPIONs, long incubation times (24 hours and more) or laborious surface functionalisation are often employed, which can adversely affect cell function. Here, we demonstrate that chemical cationisation of magnetoferritin produces a highly membrane-active nanoparticle that can magnetise human mesenchymal stem cells (hMSCs) using incubation times as short as one minute. Magnetisation persisted for several weeks in culture and provided significant T2* contrast enhancement during magnetic resonance imaging. Exposure to cationised magnetoferritin did not adversely affect the membrane integrity, proliferation and multi-lineage differentiation capacity of hMSCs, which provides the first detailed evidence for the biocompatibility of magnetoferritin. The combination of synthetic ease and flexibility, the rapidity of labelling and absence of cytotoxicity make this novel nanoparticle system an easily accessible and versatile platform for a range of cell-based therapies in regenerative medicine.

One hundred cases of mandibular fractures in children in Iraq

A survey of 476 cases of mandibular fractures in Iraq revealed that 100 cases (21%) occurred in children under the age of 13 years. Twice as many fractures were seen in the 6- to 13-year-old group than in the 0- to 5-year-old group. The male to female ratio was 2/1. The site distribution in descending order of frequency was canine region, condyle, angle body and symphysis. Of the 33 condylar fractures, only two showed signs of deviation and ankylosis. Most of these fractures were treated by simple methods of fixation.

The effect of surface charge on the thermal stability and ice recrystallization inhibition activity of antifreeze protein III (AFP III)

The aim of this study was to examine the effect of chemical cationization on the structure and function of antifreeze protein III (AFP III) over an extreme temperature range (-40°C to +90°C) using far-UV synchrotron radiation circular dichroism (SRCD) and ice recrystallization inhibition (IRI) assays. Chemical cationization was able to produce a modified AFP III with a net cationic charge at physiological pH that had enhanced resistance to denaturation at elevated temperatures, with no immediate negative impact on protein structure at subzero temperatures. Furthermore, cationized AFP III retained an IRI activity similar to that of native AFP III. Consequently, chemical cationization may provide a pathway to the development of more robust antifreeze proteins as supplementary cryoprotectants in the cryopreservation of clinically relevant cells.

A preliminary study of the dynamics of resolution of experimental haematomas: radioisotope studies in animals

A preliminary investigation was carried out in order to establish a method for the study of experimental haematomas. For this purpose haematomas were produced in rabbits by subcutaneous injection of rabbits' own blood after labelling the various blood components with appropriate radioisotopes. In addition, radioisotope labelled human serum albumin and fibrinogen were studied. The results show that there is considerable variation in the rate and pattern of dissipation of the various components of the experimentally produced haematoma. The significance of these findings is discussed.