Bacterial cellulose (BC) is produced by several microorganisms as extracellular structures and can be modified by various physicochemical and biological strategies to produce different cellulosic formats. The main advantages of BC for biomedical applications can be summarized thus: easy moldability, purification, and scalability; high biocompatibility; and straightforward tailoring. The presence of a high amount of free hydroxyl residues, linked with water and nanoporous morphology, makes BC polymer an ideal candidate for wound healing. In this frame, acute and chronic wounds, associated with prevalent pathologies, were addressed to find adequate therapeutic strategies. Hence, the main characteristics of different BC structures—such as membranes and films, fibrous and spheroidal, nanocrystals and nanofibers, and different BC blends, as well as recent advances in BC composites with alginate, collagen, chitosan, silk sericin, and some miscellaneous blends—are reported in detail. Moreover, the development of novel antimicrobial BC and drug delivery systems are discussed.

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Bacterial cellulose nanocrystals (BCNC) stand out as versatile biocolloidal building blocks for materials that are highperformance, owing to their inherently high crystallinity and specific modulus and surface area, and sustainable, as BCNC are both biobased and biodegradable. BCNC materials are also promising for their multifunctionality because of their huge potential to undergo physical and/or chemical surface modification. This is particularly appealing for biomedical applications thanks to the biocompatibility, high purity, and low toxicity of BCNC. We report on films based on surface-modified BCNC with varying contents of 3-glycidyloxypropyltrimethoxysilane (GPTMS) or 3-aminopropyltriethoxysilane (APTS). Importantly, these highly pure and crystalline needle-shaped BCNC were isolated from scraps generated at industrial operations when shaping bacterial cellulose membranes into wound dressings. The films were extensively characterized as far as their structural characteristics, with emphasis on the major features targeting at biological applications. Compared with pristine BCNC, the films performed better from the thermal stability standpoint and maintained the noncytotoxicity against nontransforming fibroblasts. The latter claim was independent of GPTMS content, but dose-dependent for APTS and valid for films containing up to 30% of this coupling agent. Altogether, this contribution expands the wingspan of nanocellulose-based materials in biomedical applications while mitigating the waste of natural resources by upcycling an industrial byproduct, falling within the circular bioeconomy framework.

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