The Biopolymer Bacterial Nanocellulose as Drug Delivery System: Investigation of Drug Loading and Release using the Model Protein Albumin

Antimicrobial functionalization of bacterial nanocellulose by loading with polihexanide and povidone-iodine

“…Although, different drugs were used it could be concluded that the amount of absorbed active agent could be controlled by the concentration of loading solution. Similar findings were obtained for small molecules like diclofenac and proteins [11,42]. However, the complex network structure of native BNC membranes makes the diffusion pathway of an active agent tortuous [14] and each alteration of this structure will influence the release behavior.…”

“…The selection of loading conditions was based on previous studies where the influence of loading time, concentration and temperature has been extensively shown [11,21]. The present antiseptics were tested in therapeutically relevant concentrations under previously optimized conditions [11,21]. While no change in color of the BNC was observed after uptake of PHMB, BNC samples loaded with PI changed their color from a milky-white to a homogenous black due to the incorporated PI.…”

“…Independent of the selected antiseptic and the sample type, loaded fleeces remained inherently stable with a smooth surface after incubation in loading solutions for 48 h under agitation at ambient temperature. The selection of loading conditions was based on previous studies where the influence of loading time, concentration and temperature has been extensively shown [11,21]. The present antiseptics were tested in therapeutically relevant concentrations under previously optimized conditions [11,21].…”

“…Purified BNC was sterilized by autoclaving (2 bar, 15 min, 121°C) and stored at 4°C until further use. The geometric sample parameters (edge length or diameter, height and weight) were measured [11] and surface area as well as volume calculated corresponding to the geometrical formula of circular cylinder or cuboid. Loading of BNC with the antiseptics in therapeutically relevant concentrations was performed on a temperature-controlled orbital shaker (KS 4000 ic control, IKA Ò -Werke, Staufen, Germany).…”

“…However, the function of BNC can be improved by inclusion of active substances into the biopolymer. For example, low molecular drugs like anesthetics, analgetics, and beta-blockers as well as metal ions, such as silver, or proteins are used in combination with BNC hydrogels for the preparation of drug delivery systems [10][11][12][13][14][15]. Silver in form of ions or nanoparticles is the active substance applied mainly [10,16,17].…”