Poly(vinyl alcohol)-tannic Acid Cryogel Matrix as Antioxidant and Antibacterial Material

Betul Ari; Mehtap Sahiner; Sahin Demirci; Nurettin Sahiner

doi:10.3390/polym14010070

Poly(vinyl alcohol)-tannic Acid Cryogel Matrix as Antioxidant and Antibacterial Material

Polymers (Basel). 2021 Dec 25;14(1):70. doi: 10.3390/polym14010070.

Authors

Betul Ari¹, Mehtap Sahiner², Sahin Demirci¹, Nurettin Sahiner^{1

3

4

5}

Affiliations

¹ Department of Chemistry, Faculty of Science & Arts, Terzioglu Campus, Canakkale Onsekiz Mart University, Canakkale 17100, Turkey.
² Faculty of Canakkale School of Applied Science, Terzioglu Campus, Canakkale Onsekiz Mart University, Canakkale 17100, Turkey.
³ Nanoscience and Technology Research and Application Center, Terzioglu Campus, Canakkale Onsekiz Mart University, Canakkale 17100, Turkey.
⁴ Department of Chemical and Biomolecular Engineering, University of South Florida, Tampa, FL 33620, USA.
⁵ Department of Ophthalmology, Morsani College of Medicine, University of South Florida, 12901 Bruce B Downs B. Downs Blv., MDC 21, Tampa, FL 33612, USA.

Abstract

The biocompatible, viscoelastic properties of poly(vinyl alcohol) (PVA) in combination with the antimicrobial and antioxidant natural polyphenolic, tannic acid (TA), and the natural flavonoid and antioxidant curcumin (Cur), were used in the preparation of PVA:TA and PVA:TA:Cur cryogel composites using cryotropic gelation to combine the individually beneficial properties. The effect of TA content on the antioxidant and antimicrobial activities of PVA:TA cryogel composites and the antioxidant activities of PVA:TA:Cur cryogel composites was determined using Trolox equivalent antioxidant capacity (TEAC) and total phenol content (TPC) assays, and were compared. The PVA:TA:Cur cryogel composite showed the highest antioxidant activity, with a TEAC value of 2.10 ± 0.24 and a TPC value of 293 ± 12.00. The antibacterial capacity of the PVA:TA and PVA:TA:Cur 1:1:0.1 cryogel composites was examined against two different species of bacteria, E. coli and S. aureus. It was found that the minimum inhibition concentration (MIC) value of the PVA:TA:Cur 1:1:0.1 cryogel composites varied between 5 and 10 mg/mL based on the type of microorganism, and the minimum bactericidal concentration (MBC) value was 20 mg/mL irrespective of the type of microorganism. Furthermore, the hemocompatibility of the PVA:TA cryogel composites was evaluated by examining their hemolytic and coagulation behaviors. PVA:TA 1:1 cryogels with a value of 95.7% revealed the highest blood clotting index value amongst all of the synthesized cryogels, signifying the potential for blood contacting applications. The release of TA and Cur from the cryogel composites was quantified at different pH conditions, i.e., 1.0, 7.4, and 9.0, and additionally in ethanol (EtOH) and an ethanol-water (EtOH:Wat) mixture. The solution released from the PVA:TA cryogels in PBS was tested for inhibition capability against α-glucosidase (E.C. 3.2.1.20). Concentration-dependent enzyme inhibition was observed, and 70 µL of 83 µg/mL PVA:TA (1:1) cryogel in PBS inhibited α-glucosidase enzyme solution of 0.03 unit/mL in 70 µL by 81.75 ± 0.96%.

Keywords: antibacterial; antioxidant; cryogel; phenolic compound; polyvinyl alcohol.

Grants and funding

FHD-2021-3485./Çanakkale Onsekiz Mart University