Bio and soft-imprinting lithography on bacterial cellulose films

• Published in: Materials today chemistry 2021-08, Vol.21, p.100535, Article 100535
• Main Authors: Roig-Sanchez, S., Fernández-Sánchez, C., Laromaine, A., Roig, A.
• Format: Article
• Language: English
• Subjects: Bacterial cellulose; Bio-lithography; Nanocellulose; Polydimethylsiloxane; Soft-imprint
• ISSN: 2468-5194; 2468-5194
• DOI: 10.1016/j.mtchem.2021.100535

Bacterial cellulose (BC) is a biocompatible polysaccharide produced by bacteria currently used in packaging, cosmetics, or health care. A highly attractive feature of BC is the possibility of patterning the BC pellicle during its biosynthesis, a concept coined as bio-lithography. BC-patterned films have demonstrated improved properties for cellular-guided growth, implant protection, or wound dressing. However, aspects such as the diversity and size of the features patterned, how those features withstand postprocessing steps, or if large areas can be patterned remain unanswered. Gathering knowledge on these characteristics could extend the use of patterned cellulose-based materials in emerging fields such as transient devices, nanogenerators, or microfluidics. Here, we show that bio-lithographed BC films present good-quality micropatterned features for various motifs (wells, pillars, and channels) in a wide range of sizes (from 200 to 5 μm) and areas as large as 70 cm2. Besides, we have studied the fidelity of the motifs and the fiber organization for wet, supercritical, and oven-dried films. When wells and pillars were patterned, the x and y dimensions were faithfully replicated in the wet and dried samples, but only wet and supercritically dried films afforded mold accuracy in the z-direction. In addition, x/z ratio should be carefully considered for obtaining self-standing pillars. Finally, we compared bio-lithography and soft-imprint lithography. In the latter case, fiber alignment was not observed and the depth of the resulting features dramatically decreased; however, this technique allowed us to produce submicron features that remain after the rewetting of the BC films. [Display omitted] •Bacterial cellulose films have been patterned by bio-lithography and by soft-imprint lithography.•Bio-lithographed patterns withstand supercritically and oven drying.•Patterned films present good quality of features in the 200-5 μm size range and for patterned areas as large as 70 cm2.•The motif's depth is maintained and the alignment of the cellulose fibers is observed under supercritically drying conditions.•Soft-imprint lithography affords submicron motifs and facilitates an easy functionalization of the films.