Bacterial Nanocellulose and Titania Hybrids: Cytocompatible and Cryopreservable Cell Carriers

Abstract

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.

Limbal Stem Cells on Bacterial Nanocellulose Carriers for Ocular Surface Regeneration

“…There are a few examples in the literature about the usage of BNC supports in stem cell culture that do not report on the need for coating BNC with ECM proteins to provide cell adhesion moieties. [48][49][50] Similarly, in our previous work with human dermal fibroblasts, [22] we found that BNC coating was not required to facilitate cell attachment. However, the here presented results prove that the plasma-assisted ECM protein functionalization is crucial for hESC-LSC attachment and survival on the BNC substrates.…”

“…[62,70] Moreover, the thermal stability of BNC enables both its sterilization by heat and cryopreservation. [22] The latest being of particular significance because it makes the cryobanking of ready-to-use hESC-LSC/BNC constructs a feasible possibility.…”

“…[21] In addition, BNC is widely regarded as a cytocompatible substrate owing it to its high chemical purity and supported by numerous in vitro investigations. [22][23][24] As for immunogenicity, BNC grafts have been found to elicit low to none inflammatory responses in vivo and to be generally well tolerated by the surrounding tissues. [25][26][27][28] Productionwise, BNC is equally appealing because of its animal-free origin, tunability and feasible scale-up.…”

“…[11] Similarly, BNC membranes were thoroughly purified until endotoxin-free before its use as cell support. [22] The palette of BNC modifications seeking to enhance cell attachment is particularly diverse. [29,30,[40][41][42] Thus, our ambition was to find a BNC conditioning rendering a favorable interface for hESC-LSC culture in a simple, well-defined and scalable process.…”

In vivosoft tissue reinforcement with bacterial nanocellulose

“…38 We have recently validated BNC in diverse biological scenarios providing data on its cytocompatibility, lack of endotoxins (0.04 ± 0.01 Endotoxin Units per mL) after its biosynthesis as well as suturability and manageability in preclinical settings. 37,39 These findings, combined with the appealing mechanical properties reported here, positioned BNC as a suitable candidate for soft tissue repair patches and therefore in vivo studies were conducted. The anti-adhesion behaviour, biocompatibility and tissue integration characteristics of the BNC patches have been evaluated with a pilot animal study.…”