Pretreated silica sand labeling using varying concentrations of tin(II) fluoride and chloride as reducing agents and different times labeling was performed in order to develop a methodology for labeling silica sand with 99mTc for using as solid radiotracer. Influence of different sand pretreatment parameters on the sorption yield (Rret%) was statistically evaluated. The effectiveness of the methods used to reduce pertechnetate (99mTcO4−) by ascending paper chromatography was confirmed. Results show relatively high values of 99mTc sorption yields on silica sand. It was possible to establish a methodology for obtaining solid 99mTc labeled radiotracers in support of silica sand.

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Nanogels-particles of polymer gels having the dimensions in the order of nanometers-are gaining attention for their wide application as biomaterials. Mainly, the nanogels are promising novel pharmaceutical carriers for small biologically active agents, bio macromolecules and can be chemically modified to incorporate various ligands for targeted drug delivery. This important factor has stimulated research on dissimilar science field such as nanotechnology and biotechnology, polymer and materials sciences, biochemistry, radiation chemistry and pharmaceutical sciences. A multitude of techniques have been described for the synthesis of this nanomaterial from polymers. However, the use of ionizing radiation (γ, e-) has demonstrated to be especially suitable for obtaining polymeric nanogels with a high degree of purity for biomedical applications, although the gamma radiation has not been widely utilized for these purposes. The aim of this paper is to develop the synthesis of PVP (polyvynilpyrrolidone) nanogels by gamma irradiation, for their evaluation as potential pharmaceutical carriers. Experiments were performed using argon saturated solution of PVP (0.1-1%). Crosslinking reactions were carried out in a gamma irradiation chamber with a 60 Co source (ISOGAMMA LLCo), at room temperature. The PVP concentration influence was evaluated in PVP solutions (0.1% and 0.25%) at 15 kGy. The SEM (scanning electron microscopy), ATR (attenuate total reflection spectroscopy), DLS (dynamic light scattering), and viscosimetry were used as characterization techniques.