Physically Cross-Linked Gels of PVA with Natural Polymers as Matrices for Manuka Honey Release in Wound-Care Applications

Abstract

Manuka honey is a well-known natural material from New Zealand, considered to have properties beneficial for burn treatment. Gels created from polyvinyl alcohol (PVA) blended with natural polymers are potential burn-care dressings, combining biocompatibility with high fluid uptake. Controlled release of manuka honey from such materials is a possible strategy for improving burn healing. This work aimed to produce polyvinyl alcohol (PVA), PVA–sodium carboxymethylcellulose (PVA-CMC), PVA–gelatin (PVA-G), and PVA–starch (PVA-S) cryogels infused with honey and to characterize these materials physicochemically, morphologically, and thermally, followed by in vitro analysis of swelling capacity, degradation/weight loss, honey delivery kinetics, and possible activity against Staphylococcus aureus. The addition of honey to PVA led to many PVA crystals with defects, while PVA–starch–honey and PVA–sodium carboxymethylcellulose–honey (PVA-CMC-H) formed amorphous gels. PVA-CMC presented the highest swelling degree of all. PVA-CMC-H and PVA–gelatin–honey presented the highest swelling capacities of the honey-laden samples. Weight loss/degradation was significantly higher for samples containing honey. Layers submitted to more freeze–thawing cycles were less porous in SEM images. With the honey concentration used, samples did not inhibit S. aureus, but pure manuka honey was bactericidal and dilutions superior to 25% honey were bacteriostatic, indicating the need for higher concentrations to be more effective.

Physically Crosslinked Poly (Vinyl Alcohol)/Kappa-Carrageenan Hydrogels: Structure and Applications

“…The fingerprint region of the IR absorption spectra (Figure 3a,b) reveals typical absorption bands of PVA, occurring at 839, 917 and 1089 cm −1 ascribed to C-C bending, -CH 2 rocking and ester C-O-C bending from the acetyl groups [39,[43][44][45]. In κ-carrageenan, the vibrations from 841, 921 and 1035 cm −1 could be assigned to -C-O-SO 3 -stretching vibrations from the galactose-4-sulphate, -CH 2 rocking from the 3,6-anhydro-D-galactose structural unit, glycosidic -C-O-C-linkage (from the 3,6 anhydro-D-galactose) and ester sulfate -S=O stretching (1159, 1235 cm −1 ) [46,47].…”

“…Supplementary, bending vibrations due to non-bonded water presence δ(O-H) are registered at ~1640 cm −1 . Also, the strong absorptions at ~2932 cm −1 (PVA) and ~2925 cm −1 (CAR) are attributed to C-H stretching [43][44][45][46][47][48][49].…”

Tensile Fatigue of Poly(Vinyl Alcohol) Hydrogels with Bio‐Friendly Toughening Agents

“… where ΔH was calculated as the area under the melting peak, is the heat needed to melt a 100% crystalline PVA (138.6 J g −1 ), and W PVA is weight fraction of the PVA polymer in the hydrogel sample with respect to deionized water. [ 50,89,90 ] Figure 7b provides a view of the trend of crystallinity degree with increasing starch.…”

“…[ 11,12,16,46–48 ] PVA hydrogels can be prepared with nontoxic reagents as well as under physiological conditions that minimize harmful responses from cells and tissue alike. [ 49,50 ] In addition, PVA‐based hydrogels are intrinsically non‐adhesive toward cells and proteins, and this allows for the creation of cell‐selective materials via incorporation with the hydrogel network. [ 49 ] The mechanical behavior of a hydrogel network based on PVA can be tuned appropriately for a given application based on the polymer concentration utilized.…”

Development and Evaluation of a Polyvinylalcohol -Cellulose Derivative-Based Film with Povidone-Iodine Predicted for Wound Treatment

“…We sought to combine the mechanical and swelling properties of PVA with the flexibility and high water uptake of cellulose derivatives, and assessed the subacute toxicity of the PVP-I carrier composition in a rat model. In earlier studies on base PVA and PVA with CMC, PVA with starch, or PVA with gelatin, PVA with chitosan obtained wound dressings, cryogels, and soft microporous sponges, and reported an excellent mechanical integrity, biocompatibility, and biodegradability, which helped to maintain a moisturized environment near the wounds [ 35 , 36 , 37 , 38 , 39 ]. The dressings we prepared (with PVA-HPMC, as with other combinations described in the literature) are characterized by enhanced properties, i.e., swelling or flexibility relative to pure PVA [ 40 , 41 ].…”