RESUMO
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.
RESUMO
Agro-industrial wastes to be a global concern since agriculture and industrial processes are growing exponentially with the fast increase of the world population. Biopolymers are complex molecules produced by living organisms, but also found in many wastes or derived from wastes. The main drawbacks for the use of polymers are the high costs of the polymer purification processes from waste and the scale-up in the case of biopolymer production by microorganisms. However, the use of biopolymers at industrial scale for the development of products with high added value, such as food or biomedical products, not only can compensate the primary costs of biopolymer production, but also improve local economies and environmental sustainability. The present review describes some of the most relevant aspects related to the synthesis of hybrid materials and nanocomposites based on biopolymers for the development of products with high-added value.
Assuntos
Resíduos Industriais , Polímeros , Agricultura , Biopolímeros , AlimentosRESUMO
A nanocomposite based on bacterial cellulose (BC) containing montmorillonite (MMT) modified with silver (BC-MMT-Ag) was developed to be used as potential scaffold for wound healing. Montmorillonite was suspended in silver nitrate solution to incorporate silver in the matrix by ion exchange. The derivative silver clay suspension was used to modify bacterial cellulose membranes by ex situ technique. The BC nanocomposite was analyzed by thermal analysis, scanning electron microscopy, Fourier transform infrared and electron dispersion spectroscopies, X-ray diffraction, and rehydration capacity. The antimicrobial activity of the silver montmorillonite-bacterial cellulose nanocomposite was challenged in cultures of Gram(+) Staphylococcus aureus and Gram(-) Pseudomonas aeruginosa, and showed inhibition of growth in agar plates and biofilm formation as revealed by live-dead assay. Cytotoxicity of BC nanocomposites containing 1% to 25% of MMT-Ag showed good in vitro biocompatibility with L929 fibroblast cells.