Danışman-Kalındemirtaş, Ferdane; Sert, Esra; Tan, Ezgi; Akyüz, Esin; Karakuş, Selcan

In recent years, the development of green multifunctional nanoformulations with specific anticancer activity has gained importance among scientists. In the present study, Camelia sinensis extract/CuO nanoparticles (CSE/CuO NPs) and cisplatin (Cis)-loaded CSE/CuO NPs were prepared and characterized by various TEM, XRD, FTIR, and UV-Vis techniques. The antioxidant properties of the green CSE/CuO NPs were evaluated using the CUPRIC Reducing Antioxidant Capacity (CUPRAC) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS)/HRP methods. The drug release profile of the NPs was studied at pH 7.4 and pH 5.5. Additionally, the cytotoxic effects of CSE/CuO NPs and Cis-loaded CSE/CuO NPs on MIA-PaCa-2 pancreatic cancer were evaluated using the MTT assay and compared with normal HUVEC cells. Subsequently, the apoptotic activity of CSE/CuO NPs and Cis-loaded CSE/CuO NPs on MIA-PaCa-2 cells was evaluated using Annexin-V FITC, and their effects on multi-drug resistance were determined using the ABCG2 antibody by flow cytometric analysis. Our results showed that Cis-loaded CSE/CuO NPs exhibited a pH-sensitive drug release profile. CSE/CuO NPs were highly cytotoxic to MIA-PaCa-2 pancreatic cancer cells, while exhibiting very low cytotoxicity to HUVEC cells. Moreover, CSE/CuO NPs and Cis-loaded CSE/CuO NPs were found to have higher apoptotic activity and lower drug resistance compared to free Cis. Although many studies have been conducted with CSE, this study was the first to show that CSE/CuO NPs were dominantly and selectively effective against pancreatic cancer, and resistance to Cis and its side effects could be significantly reduced by CSE-derived nanocarriers. Additionally, for the first time, the antioxidant property was investigated by applying CUPRAC and ABTS methods. Graphical Abstract: (Figure presented.)

Karahalil, Ercan; Germec, Mustafa; Karaoglan, Mert; Yatmaz, Ercan; Coban, Hasan Bugra; Inan, Mehmet; Turhan, Irfan

Mannanases are of great importance as they are able to hydrolyze polysaccharides for industrial applications and can be easily produced by fermentation. Purification of a β-mannanase produced from carob extract in a bioreactor is of great importance in order to obtain information about its structural and functional features and to foresee its implementations. Therefore, the aims of this study were to purify a β-mannanase from Aspergillus fumigatus expressed in Aspergillus sojae grown on carob extract by implementation of various flocculant agents in the fermentation medium, followed by the determination of its physico-chemical, kinetic, and thermodynamic characteristics. Flocculants increase the visible size of the dispersed particles by agglomeration, simplifying the separation of solids and liquids, and thereby reducing process costs. Optimum flocculation conditions for chitosan- and PAC-PAM-implemented processes were determined as 40 mg/L of chitosan, 30 min of implementation time, no agitation and 3 g/L PAC-PAM, 30 min implementation time, and no agitation. Under these conditions, more than a 2-fold increase in the enzyme activity was achieved in both flocculation processes. Further investigations determined molecular weight, optimum pH, and temperature values of the produced β-mannanase to be 56–60 kDa, pH 6, and 60 °C, respectively. Additionally, Km and Vm determination of the enzyme for various substrates concluded that the β-mannanase showed the highest substrate specificity against locust bean gum among the substrates evaluated. Furthermore, experimental results for substrate specificity were further modeled and successfully represented by the Weibull model. In conclusion, this study provides valuable and important information about β-mannanase production and purification for industrial-scale applications.