A nanocellulose-gelatin (bacterial cellulose gelatin (BCG)) film was developed by a supplement of gelatin, at a concentration of 1%–10% w/v, in a coconut-water medium under the static cultivation of Acetobacter xylinum. The two polymers exhibited a certain degree of miscibility. The BCG film displayed dense and uniform homogeneous structures. The Fourier transform infrared spectroscopy (FTIR) results demonstrated interactions between the cellulose and gelatin. Incorporation of gelatin into a cellulose nanofiber network resulted in significantly improved optical transparency and water absorption capacity of the films. A significant drop in the mechanical strengths and a decrease in the porosity of the film were observed when the supplement of gelatin was more than 3% (w/v). The BCG films showed no cytotoxicity against Vero cells.
Thin films of bacterial cellulose (BC) from a nata de coco culture system were developed, characterized, and investigated for the growth of human keratinocytes and fibroblasts. The average pore diameter and total surface area of the dried BC films estimated by BET were 224 Å and 12.62 m2/g, respectively. With an film thickness of 0.12 mm, the average tensile strength and break strain of the dried films were 5.21 MPa and 3.75%, whereas those of the wet films were 1.56 MPa and 8.00%, respectively. The water absorption capacity of air‐dried film was 5.09 g water/g dried films. For uses in the therapy of skin wounds, the potential biological mechanism of action of BC film was evaluated by using human keratinocytes and fibroblasts. Our results were the first direct demonstration that BC film supported the growth, spreading, and migration of human keratinocytes but not those of human fibroblasts. Expressions of E‐cadherin and the α‐3 chain of laminin confirmed the phenotype of human keratinocytes on BC film.
Multifunctional biopolymer composites comprising mechanically-disintegrated bacterial cellulose, alginate, gelatin and curcumin plasticized with glycerol were successfully fabricated through a simple, facile, cost-effective mechanical blending and casting method. SEM images indicate a well-distributed structure of the composites. The water contact angles existed in the range of 50–70°. Measured water vapor permeability values were 300–800 g/m2/24 h, which were comparable with those of commercial dressing products. No release of curcumin from the films was observed during the immersion in PBS and artificial saliva, and the fluid uptakes were in the range of 100–700%. Films were stretchable and provided appropriate stiffness and enduring deformation. Hydrated films adhered firmly onto the skin. In vitro mucoadhesion time was found in the range of 0.5–6 h with porcine mucosa as model membrane under artificial saliva medium. The curcumin-loaded films had substantial antibacterial activity against E. coli and S. aureus. The films showed non-cytotoxicity to human keratinocytes and human gingival fibroblasts but exhibited potent anticancer activity in oral cancer cells. Therefore, these curcumin-loaded films showed their potential for use as leave-on skin applications. These versatile films can be further developed to achieve desirable characteristics for local topical patches for wound care, periodontitis and oral cancer treatment.
Films of bacterial cellulose (BC) reinforced by natural rubber (NR) with remarkably high mechanical strength were developed by combining the prominent mechanical properties of multilayer BC nanofibrous structural networks and the high elastic hydrocarbon polymer of NR. BC pellicle was immersed in a diluted NR latex (NRL) suspension in the presence of ethanol aqueous solution. Effects of NRL concentrations (0.5%–10% dry rubber content, DRC) and immersion temperatures (30–70 °C) on the film characteristics were studied. It was revealed that the combination of nanocellulose fibrous networks and NR polymer provided a synergistic effect on the mechanical properties of NR–BC films. In comparison with BC films, the tensile strength and elongation at break of the NR–BC films were considerably improved ~4-fold. The NR–BC films also exhibited improved water resistance over that of BC films and possessed a high resistance to non-polar solvents such as toluene. NR–BC films were biodegradable and could be degraded completely within 5–6 weeks in soil.
3 December 2007 in Journal of Applied Polymer Science