Loading...
2 results
Search Results
Now showing 1 - 2 of 2
- Bacterial cellulose: a versatile biopolymer for wound dressing applicationsPublication . Portela, Raquel; R. Leal, Catarina; Almeida, Pedro L.; Sobral, RitaAlthough several therapeutic approaches are available for wound and burn treatment and much progress has been made in this area, room for improvement still exists, driven by the urgent need of better strategies to accelerate wound healing and recovery, mostly for cases of severe burned patients. Bacterial cellulose (BC) is a biopolymer produced by bacteria with several advantages over vegetal cellulose, such as purity, high porosity, permeability to liquid and gases, elevated water uptake capacity and mechanical robustness. Besides its biocompatibility, BC can be modified in order to acquire antibacterial response and possible local drug delivery features. Due to its intrinsic versatility, BC is the perfect example of a biotechnological response to a clinical problem. In this review, we assess the BC main features and emphasis is given to a specific biomedical application: wound dressings. The production process and the physical-chemical properties that entitle this material to be used as wound dressing namely for burn healing are highlighted. An overview of the most common BC composites and their enhanced properties, in particular physical and biological, is provided, including the different production processes. A particular focus is given to the biochemistry and genetic manipulation of BC. A summary of the current marketed BC-based wound dressing products is presented, and finally, future perspectives for the usage of BC as wound dressing are foreseen.
- Motility and cell shape roles in the rheology of growing bacteria culturesPublication . Portela, Raquel; Almeida, Pedro L.; Sobral, Rita; R. Leal, CatarinaCell shape, size and self-motility appear as determinant intrinsic cell factors in the rheological behavior of living bacterial cultures during the growth process. In this work three different species were considered due to their differences on these intrinsic characteristics: two different strains of Staphylococcus aureus – strain COL and its isogenic cell wall autolysis mutant, RUSAL9 – both non-motile and Escherichia coli and Bacillus subtilis – both presenting intrinsic motility. In situ real-time rheology, was used to characterize the activity of growing bacteria, under steady-shear conditions, in particular the viscosity growth curve was measured, for a constant shear flow rate, presenting for all studied cultures, different and rich flow curves. These complex rheological behaviors are a consequence of two coupled effects: the cell density continuous increase and its changing interacting properties, where cell size and shape and intrinsic motility are major players.