This study evaluated the effect of solubilized and dispersed bacterial cellulose (BC) on the physicochemical characteristics and drug release profile of hydrogels synthesized using biopolymers. Superabsorbent hydrogels were synthesized by graft polymerization of acrylamide on BC solubilized in an NaOH/urea solvent system and on dispersed BC by using N,N′-methylenebisacrylamide as a crosslinker under microwave irradiation. Fourier transform infrared spectroscopy analysis of the resulting hydrogels confirmed the grafting, and an X-ray diffraction pattern showed a decrease in the crystallinity of BC after the grafting process. The hydrogels exhibited pH and ionic responsive swelling behavior, with hydrogels prepared using solubilized BC (SH) having higher swelling ratios. Furthermore, compared to the hydrogels synthesized using dispersed BC, the hydrogels synthesized using solubilized BC showed higher porosity, drug loading efficiency, and release. These results suggest the superiority of the hydrogels prepared using solubilized BC and that they should be explored further for oral drug delivery. 1. Introduction Currently, natural polymers are being extensively explored for the fabrication of hydrogels, owing to their biodegradability, biocompatibility, nontoxicity, and availability. Consequently, considerable attention has been given to bacterial cellulose (BC), a natural polymer, because of its high mechanical strength, thermal stability, biocompatibility, and purity [1]. However, its application in the synthesis of hydrogels is limited by its insolubility in common solvents owing to strong inter- and intramolecular hydrogen bonding. Thus, solubilization of BC in appropriate solvents could extend its application in the fabrication of films, hydrogels, and membranes and improve its purity and mechanical strength for pharmaceutical and biomedical applications. Although this macromolecule has been successfully solubilized in lithium chloride/N,N-dimethylacetamide [2] and N-methylmorpholine-N-oxide monohydrate [3], its use is limited to laboratory-scale operation because it is highly toxic. To overcome this challenge, a sodium hydroxide (NaOH) complex solvent was prepared. Cellulose with a low degree of polymerization (DP < 300) has been reported to easily dissolve in NaOH (7–10%？w/v) at low temperatures (？5°C to ？15°C) [4]. Conversely, cellulose with a high degree of polymerization (DP > 300) has been found not to be easily dissolve in NaOH solution alone [5]. The degree of polymerization of BC is in the range of 2000 and 6000 [6], but in some cases it
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