Natalia O. Gegel, Tatiana S. Babicheva, Anna B. Shipovskaya Saratov Fall Meeting 2016 SEM examination of structural changes in chitosan microtubes during their in vitro biodegradation Natalia O. Gegel, Tatiana S. Babicheva, Anna B. Shipovskaya  Research and Education Institution of Nanostructures and Biosystems, Saratov State University

Abstract Structural changes in chitosan microtubes during their in vitro biodegradation in model enzymatic media were examined by SEM. The surface relief and morphology of the microtube’s wall have been found to change when the samples are kept in an enzymatic medium, micropores and defects being appeared.

Scanning electron microscopy (SEM) Objects of research The microtubule derived from chitosan solutions of glycolic acid in the dry-wet method Research methods Scanning electron microscopy (SEM)

The initial wall surface microtubule chitosan for 6 months in studies of enzymatic biodegradation medium (a) (b) (c) (d) Fig.1. SEM images of microtubes inside surface chitosan stored at a temperature of 37 °C in phosphate buffer 0 (a), 60 (b) 120 (c) and 180 (d) days.

(a) (b) (c) (d) SEM images of microtubes inside surface chitosan stored at a temperature of 37 ° C in fermentation medium 0 (a), 60 (b) 120 (c) and 180 (d) days.

of 37 °C in the fermentation broth 120 (a) 150 (b) and 180 (c) days. SEM images of microtubes inside surface chitosan stored at a temperature of 37 °C in the fermentation broth 120 (a) 150 (b) and 180 (c) days.

Conclusions As seen in the control experiment, over 180 days (Fig. 1) of serious defects on the wall surface microtubule chitosan was not formed. However, the observed changes in the microrelief after 120 days since at the sample surface micropores formed. For microtubule chitosan subjected to enzymatic hydrolysis, and the time rate of change of the surface morphology is different. After 60 days the sample micro-relief wall has changed, the surface became more developed (Fig. 2b). After 120 days the sample surface became loose and micropores were formed (Fig. 2). In the coming 180 days under the action of the enzyme increased the pores. For microtubes chitosan subjected to the action of lysozyme, recorded severe surface defects (Fig. 3). After 120 days on the surface of the sample appeared bulk defects in the form of depressions in the inner layers microtubule chitosan. Upon expiration of 150 days, they increased in screen size and quantity over the entire surface (Fig. 5.10 b). After 180 days the study increased defects on the surface and at times reached a diameter of 158 mm (Fig. 5.10 c).