Laminated multifunctional bacterial cellulose nanocomposite with a millefeuille topographic distribution of inorganic nanoparticles.

In this mini-review, we highlight the potential of the biopolymer bacterial cellulose to treat damaged epithelial tissues. Epithelial tissues are cell sheets that delimitate both the external body surfaces and the internal cavities and organs. Epithelia serve as physical protection to underlying organs, regulate the diffusion of molecules and ions, secrete substances and filtrate body fluids, among other vital functions. Because of their continuous exposure to environmental stressors, damage to epithelial tissues is highly prevalent. Here, we first compare the properties of bacterial cellulose to the current gold standard, collagen, and then we examine the use of bacterial cellulose patches to heal specific epithelial tissues; the outer skin, the ocular surface, the oral mucosa and other epithelial surfaces. Special emphasis is made on the dermis since, to date, this is the most widespread medical use of bacterial cellulose. It is important to note that some epithelial tissues represent only the outermost layer of more complex structures such as the skin or the cornea. In these situations, depending on the penetration of the lesion, bacterial cellulose might also be involved in the regeneration of, for instance, inner connective tissue.

Integrating multimodal imaging modalities in PLGA protein carriers.

Bacterial nanocellulose exhibits valuable properties to act as a corneal bandage material in terms of conformability, suturability, durability and ease of manipulation in ophthalmological environments.

Carrier-assisted cell transplantation offers new strategies to improve the clinical outcomes of cellular therapies. Bacterial nanocellulose (BC) is an emerging biopolymer that might be of great value in the development of animal-free, customizable and temperature-stable novel cell carriers. Moreover, BC exhibits a myriad of modification possibilities to incorporate additional functionalities. Here, we have synthesized BC-titanium dioxide (TiO2) nanocomposites (BC/TiO2) to evaluate and compare the suitability of not only BC but also a model hybrid nanobiomaterial as cell transplantation supports. This work provides thorough information on the interactions between BC-based substrates and model human cells in terms of cell attachment, morphology, proliferation rate and metabolic activity. Two methods to partially retrieve the adhered cells are also reported. Both BC and BC/TiO2 substrates are positively evaluated in terms of cytocompatibility and endotoxin content without detecting major differences between BC and BC nanocomposites. Lastly, the effective cryopreservation of cells-BC and cells-BC/TiO2 constructs, yielding high cell viability and intact cell carriers after thawing, is demonstrated. Taken together, our results show that both BC and BC/TiO2 enable to integrate the processes of expansion and long-term storage of human cells in transportable, robust and easy to manipulate supports. We expect these findings to encourage further applications of BC-based biomaterials in cellular therapies and to prompt research on BC-nanocomposites exhibiting advanced functionalities.

The use of surgical meshes to reinforce damaged internal soft tissues has been instrumental for successful hernia surgery; a highly prevalent condition affecting yearly more than 20 million patients worldwide....

Limbal stem cells (LSCs) are already used in cell‐based treatments for ocular surface disorders. Clinical translation of LSCs‐based therapies critically depends on the successful delivery, survival, and retention of these therapeutic cells to the desired region. Such a major bottleneck could be overcome by using an appropriate carrier to provide anchoring sites and structural support to LSC culture and transplantation. Bacterial nanocellulose (BNC) is an appealing, yet unexplored, candidate for this application because of its biocompatibility, animal‐free origin and mechanical stability. Here, BNC as a vehicle for human embryonic stem cells‐derived LSC (hESC‐LSC) are investigated. To enhance cell‐biomaterial interactions, a plasma activation followed by a Collagen IV and Laminin coating of the BNC substrates is implemented. This surface functionalization with human extracellular matrix proteins greatly improved the attachment and survival of hESC‐LSC without compromising the flexible, robust and semi‐transparent nature of the BNC. The surface characteristics of the BNC substrates are described and a preliminary ex vivo test in simulated transplantation scenarios is provided. Importantly, it is shown that hESC‐LSC retain their self‐renewal and stemness characteristics up to 21 days on BNC substrates. These results open the door for future research on hESC‐LSC/BNC constructs to treat severe ocular surface pathologies.

Bacterial nanocellulose (BNC) is usually produced as randomly‐organized highly pure cellulose nanofibers films. Its high water‐holding capacity, porosity, mechanical strength, and biocompatibility make it unique. Ordered structures are found in nature and the properties appearing upon aligning polymers fibers inspire everyone to achieve highly aligned BNC (A‐BNC) films. This work takes advantage of natural bacteria biosynthesis in a reproducible and straightforward approach. Bacteria confined and statically incubated biosynthesized BNC nanofibers in a single direction without entanglement. The obtained film is highly oriented within the total volume confirmed by polarization‐resolved second‐harmonic generation signal and Small Angle X‐ray Scattering. The biosynthesis approach is improved by reusing the bacterial substrates to obtain A‐BNC reproducibly and repeatedly. The suitability of A‐BNC as cell carriers is confirmed by adhering to and growing fibroblasts in the substrate. Finally, the thermal conductivity is evaluated by two independent approaches, i.e., using the well‐known 3ω‐method and a recently developed contactless thermoreflectance approach, confirming a thermal conductivity of 1.63 W mK−1 in the direction of the aligned fibers versus 0.3 W mK−1 perpendicularly. The fivefold increase in thermal conductivity of BNC in the alignment direction forecasts the potential of BNC‐based devices outperforming some other natural polymer and synthetic materials.