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Applications of Ionizing Radiations | Progress Report 61
Figure 28. SEM image of cellulose-g-PGMA copolymer with DG of 25% before (a) and after (b) EDA modification (Barsbay, M., et al. http://dx.
doi.org/10.1016/j.radphyschem.2015.12.015i).
linking has been recently established. Such cific site delivery. This study was performed
materials acquire specific properties that led with Dr. Gustavo Varca collaboration.
to a great deal of potential applications, in-
cluding drug delivery systems, nanosensors, Controlled radical polymerization
nanoreactors, and bio-mimetic mechanical and grafting onto polymeric
devices. In this work, we developed poly(vi- substrates using ionizing radiation
nyl-1-pyrrolidone) nanogels, synthesized by
ionizing radiation. Additionally, we aimed This research was developed during training
to produce PVP albumin conjugate system (IAEA fellowship) at Department of Chemistry,
for biomedical applications. On this account, Hacettepe University, Turkey, conducted by Dr.
PVP was irradiated in gamma and electron Murat Barsbay and coordinated by Dr. Olgun
beam sources using cosolvent system (water/ Güven. Modifying the surface properties of
acetone) at room temperature. Bovine serum polymers, like cellulose, is not only desirable
albumin was incorporated after nanogel for- but also very important to control the sur-
mation, by resuspension of the lyophilized face interactions and responses which are
nanogel using saturated protein solution. required especially in adsorption, separation,
The produced systems were characterized and biotechnology applications. Cellulose
by means of particle size, using dynamic light linear chains have a large number of hydroxyl
scattering. Nanostructure images were ob- groups capable of forming hydrogen bonds
tained by scanning electron microscopy. Un- between and within the chains, making it
der the evaluated conditions, it was possible possible to functionalize cellulose through the
to synthetize nanostructured PVP hydrogels well-established methods such as esterifica-
around 30-80nm hydrodynamic radius. The tion. So, by means of a single reactive polymer
addition of protein to the system conferred it would be possible to obtain a variety of dif-
distinct thermal profiles and led to changes ferent materials with characteristics achieved
in the overall structure of the system. Appli- by the modifying reagent. The grafting tech-
cations of the developed polymer albumin nique can be improved and yield superior
conjugate involve drug delivery systems with results when it is performed in conjunction
enhanced biological compatibility and spe- with controlled radical polymerization (CRP)
