Hydrogen peroxide loaded cellulose acetate mats as controlled topical O2 delivery devices

Abstract

a b s t r a c tIn this study, sub and supercritical CO 2 are used as effective solvents to impregnate hydrogen peroxide (H 2 O 2 ) into cellulose acetate (CA) non-woven mats. As much as 25 wt% H 2 O 2 can be impregnated at operating conditions of 25-45 • C and 1200 psig. Thermal gravimetric analysis shows that H 2 O 2 -loaded CA mats lose more than 60% of available H 2 O 2 when quickly heated to 37 • C and held at this temperature for 60 min. However, in comparison, pure H 2 O 2 -H 2 O (50:50 w/w) solution evaporates 100% within 15 min at this same temperature. Shelf-life studies show that H 2 O 2 -loaded CA mats lose ∼50% and ∼100% of available H 2 O 2 in 30 days, when stored at 2-8 • C and 20-23 • C, respectively. H 2 O 2 slowly diffuses and subsequently evaporates from the CA mat at a rate determined by the diffusion of H 2 O 2 through the CA fibers. We envision applying a thin polymer coating to the CA mat to suppress diffusional losses of H 2 O 2 , thus leading to an increased product shelf-life. These mats should find use as bandages for the continuous delivery of O 2 for advanced wound care. In vitro studies presented here demonstrate that the developed bandages produce O 2 at a controlled rate for 24 h.

Cellulose Acetate Based Material with Antibacterial Properties Created by Supercritical Solvent Impregnation

“…This phenomenon can be explained by participation of carvacrol with its hydroxyl group in intermolecular hydrogen bonds between CA chains leading to the change in solid structure of CA. Mallepally et al [7] showed that loading of up to 25% of hydrogen peroxide did not affect morphology of CA mats. Shen et al [8] also reported that loading of up to 10% of vanillin and L-menthol into CA fiber did not affect the morphology.…”

“…Amount of impregnated active substance and porous structure of the substrate (carrier) are of vital importance for controlled drug delivery and its efficiency against target bacterial strains. Amount of impregnated additive depends on complex interactions of ternary system (additivesupercritical fluid-polymer) which are affected by CO 2 pressure, temperature, nature of polymer, and time of its exposure to supercritical fluid [4,7,9]. Previous studies demonstrated that pure scCO 2 had negligible effect on CA morphology and thermal properties [5,8].…”

“…Some of previous reports on CO 2 -assisted impregnation of additives into CA present products with different end applications. Mallepally and coworkers [7] produced controlled topical oxygen delivery device by impregnation of CA with hydrogen peroxide at pressure of 8.3 MPa and temperatures from 25 to 45 ∘ C during 1 h with a maximum impregnation yield of 25%. Shen and coworkers [8] impregnated CA with vanillin and L-menthol at pressures from 5.2 to 17.6 MPa and temperatures from 20 to 50 ∘ C during 2 h with impregnation yields up to 20% for possible application in the food industry.…”

“…Reportedly, supercritical carbon dioxide (scCO 2 ) can be used to load polymeric carriers with antimicrobial substances [2][3][4][5][6][7][8][9][10][11][12], vitamins [13], drugs [14,15], dyes [16,17], and so on. There are two distinctive mechanisms of SSI.…”

“…Promising prospective of carvacrol applications has stimulated researchers to study its incorporation into different polymers (e.g., cyclodextrin, cellulose, gelatin, and chitosan) for different purposes [10,11,23,24]. Cellulose acetate (CA) holds a great promise for food, pharmaceutical, and medicinal applications since it is stable, biocompatible, bioresorbable, and derived from cellulose, the world's most abundant biopolymer [7,[25][26][27]. Its good properties stimulated research focused on the generation of CA structures (membranes, foams, microparticles etc.)…”