Cryostructuring of Polymeric Systems: 64. Preparation and Properties of Poly(vinyl alcohol)-Based Cryogels Loaded with Antimicrobial Drugs and Assessment of the Potential of Such Gel Materials to Perform as Gel Implants for the Treatment of Infected Wounds

Abstract

Physical macroporous poly(vinyl alcohol)-based cryogels formed by the freeze-thaw technique without the use of any foreign cross-linkers are of significant interests for biomedical applications. In the present study, such gel materials loaded with the antimicrobial substances were prepared and their physicochemical properties were evaluated followed by an assessment of their potential to serve as drug carriers that can be used as implants for the treatment of infected wounds. The antibiotic Ceftriaxone and the antimycotic Fluconazole were used as antimicrobial agents. It was shown that the Ceftriaxone additives caused the up-swelling effects with respect to the cryogel matrix and some decrease in its heat endurance but did not result in a substantial change in the gel strength. With that, the drug release from the cryogel vehicle occurred without any diffusion restrictions, which was demonstrated by both the spectrophotometric recording and the microbiological agar diffusion technique. In turn, the in vivo biotesting of such drug-loaded cryogels also showed that these materials were able to function as rather efficient antimicrobial implants injected in the artificially infected model wounds of laboratory rabbits. These results confirmed the promising biomedical potential of similar implants.

Keywords: Ceftriaxone; Fluconazole; antimicrobial implants; drug release; in vitro and in vivo bioassay; poly(vinyl alcohol) cryogel.

Figure 1

(a) Chemical structures of Ceftriaxone [89] and (b) Fluconazole [90].

Figure 2

The appearance of the PVACG samples molded in the shapes of a cylinder (a) and the 3-mm-thick discs of different diameter (b,c).

Figure 3

The values of the volume (a), compression Young’s modulus (b), and fusion temperature (c) of the PVA cryogels prior to and after loading the samples with CFT.

Figure 4

Kinetic profile of CFT release from the drug-loaded PVACG.

Figure 5

Growth inhibition zones for three strains of bacterial cells around the CFT-loaded PVACG-based carrier after 48 h of incubation.

Figure 6

Histological sections of rabbit tissues of the experimental groups: (a)—group 1; (b)—group 2; (c)—group 3, low magnification; (c’)—group 3, a higher magnification; (d)—group 4; (e)—group 5 (for denotations and explanations see the text above this figure).