Bacterial cellulose nanocrystals obtained through enzymatic and acidic routes: A comparative study of their main properties and in vitro biological responses.

Cellulose nanocrystals (CNCs) are crystalline domains isolated from cellulosic fibers. They have been utilized in a wide range of applications, such as reinforcing fillers, antibacterial agents and manufacturing of biosensors. Whitin this context, the aim of this work was to obtain and analyze CNCs extracted from bacterial nanocellulose (BNC) using two distinct methods combined with milling pre-treatment: an acidic hydrolysis using 64 % sulfuric acid and an enzymatic hydrolysis using a commercial cellulase enzyme mixture. The CNCs obtained from the enzymatic route (e-CNCs) were observed to be spherical nanoparticles with diameter of 56 ± 11 nm. In contrast, the CNCs from the acid hydrolysis (a-CNCs) appeared as needle-shaped nanoparticles with a high aspect ratio with lengths/widths of 158 ± 64 nm/11 ± 2 nm. The surface zeta potential (ZP) of the a-CNCs was -30,8 mV, whereas the e-CNCs has a potential of +2.70 ± 3.32 mV, indicating that a-CNCs consisted of negatively charged particles with higher stability in solution. Although the acidic route resulted in nanocrystals with a slightly higher crystallinity index compared to the enzymatic route, e-CNCs was found to be more thermally stable than BNC and a-CNCs. Here, we also confirmed the safety of a-CNCs and e-CNCs using L929 cell line. Lastly, this article describes two different CNCs synthesis approaches that leads to the formation of nanoparticles with different dimensions, morphology and unique physicochemical properties. To the best of our knowledge, this is the first study to yield spherical nanoparticles as a result of BNC enzymatic treatment.

Biocellulose-based hydrogel dressing as a strategy for the management of chronic arterial wounds.

PURPOSE: To evaluate using a biocellulose-based hydrogel as an adjuvant in the healing process of arterial ulcers. METHODS: A prospective single group quasi-experimental study was carried out with chronic lower limb arterial ulcer patients. These patients received biocellulose-based hydrogel dressings and outpatient guidance on dressing and periodic reassessments. The primary outcomes were the ulcer-healing rate and product safety, which were assessed by ulcer area measured in photographic records of pre-treatment and posttreatment after 7, 30, and 60 days. Secondary outcomes were related to clinical assessment by the quality-of-life scores (SF-36 and EQ-5D) and pain, evaluated by the visual analogue scale (VAS). RESULTS: Seventeen participants were included, and one of them was excluded. Six patients (37%) had complete wound healing, and all patients had a significant reduction in the ulcer area during follow-up (233.6mm2 versus 2.7mm2) and reduction on the score PUSH 3.0 (p < 0.0001). The analysis of the SF-36 and EQ-5D questionnaires showed a statistically significant improvement in almost all parameters analyzed and with a reduction of pain assessed by the VAS. CONCLUSIONS: The biocellulose-based hydrogel was safe and showed a good perspective to promoting the necessary conditions to facilitate partial or complete healing of chronic arterial ulcers within a 60-day follow-up. Quality of life and pain were positively affected by the treatment.

Review of Bacterial Nanocellulose as Suitable Substrate for Conformable and Flexible Organic Light-Emitting Diodes.

As the development of nanotechnology progresses, organic electronics have gained momentum in recent years, and the production and rapid development of electronic devices based on organic semiconductors, such as organic light-emitting diodes (OLEDs), organic photovoltaic cells (OPVs), and organic field effect transistors (OFETs), among others, have excelled. Their uses extend to the fabrication of intelligent screens for televisions and portable devices, due to their flexibility and versatility. Lately, great efforts have been reported in the literature to use them in the biomedical field, such as in photodynamic therapy. In tandem, there has been considerable interest in the design of advanced materials originating from natural sources. Bacterial nanocellulose (BNC) is a natural polymer synthesized by many microorganisms, notably by non-pathogenic strains of Komagataeibacter (K. xylinus, K. hansenii, and K. rhaeticus). BNC shows distinct physical and mechanical properties, including its insolubility, rapid biodegradability, tensile strength, elasticity, durability, and nontoxic and nonallergenic features, which make BNC ideal for many areas, including active and intelligent food packaging, sensors, water remediation, drug delivery, wound healing, and as conformable/flexible substrates for application in organic electronics. Here, we review BNC production methods, properties, and applications, focusing on electronic devices, especially OLEDs and flexible OLEDs (FOLEDs). Furthermore, we discuss the future progress of BNC-based flexible substrate nanocomposites.

Biocellulose-based hydrogel dressing as a strategy for the management of chronic arterial wounds

Purpose: To evaluate using a biocellulose-based hydrogel as an adjuvant in the healing process of arterial ulcers. Methods: A prospective single group quasi-experimental study was carried out with chronic lower limb arterial ulcer patients. These patients received biocellulose-based hydrogel dressings and outpatient guidance on dressing and periodic reassessments. The primary outcomes were the ulcer-healing rate and product safety, which were assessed by ulcer area measured in photographic records of pre-treatment and posttreatment after 7, 30, and 60 days. Secondary outcomes were related to clinical assessment by the quality-of-life scores (SF-36 and EQ-5D) and pain, evaluated by the visual analogue scale (VAS). Results: Seventeen participants were included, and one of them was excluded. Six patients (37%) had complete wound healing, and all patients had a significant reduction in the ulcer area during follow-up (233.6mm2 versus 2.7mm2) and reduction on the score PUSH 3.0 (p < 0.0001). The analysis of the SF-36 and EQ-5D questionnaires showed a statistically significant improvement in almost all parameters analyzed and with a reduction of pain assessed by the VAS. Conclusions: The biocellulose-based hydrogel was safe and showed a good perspective to promoting the necessary conditions to facilitate partial or complete healing of chronic arterial ulcers within a 60-day follow-up. Quality of life and pain were positively affected by the treatment.