Production and evaluation of biosynthesized cellulose tubes as promising nerve guides for spinal cord injury treatment.

Spinal cord injury (SCI) is a central nervous disorder that can result in permanent motor and sensory damage due to a severed communication pathway. Although there is currently no effective treatment, nerve guide tubes have been used to bridge the injured stumps and act as drug delivery systems. In this study, biosynthesized cellulose (BC) nerve guides were prepared, and nerve growth factor (NGF)-a model growth factor-was incorporated into the tubular nerve guide in order to obtain a nerve guide/drug delivery system to assist the regeneration. To achieve this, Gluconacetobacter hansenii was cultivated in a special bioreactor to produce biosynthesized cellulose tubes (BCTs) in situ, and the physical and mechanical properties of the BCTs obtained from different cultivation time points were evaluated. Our results showed that the properties of the BCTs were comparable to those of the native human neural tissues, and that the NGF released from the BCTs was bioactive for at least 7 days as evaluated by PC12 cell cultures in vitro. In summary, this study evaluated the use of BCT as a drug releasing nerve guide, and our results showed that the BCT is an attractive strategy to enhance nerve regeneration after the SCI.

N-(1'-naphthyl)-3,4,5-trimethoxybenzohydrazide as microtubule destabilizer: Synthesis, cytotoxicity, inhibition of cell migration and in vivo activity against acute lymphoblastic leukemia.

Tubulin-interacting agents, like vinca alkaloid and taxanes, play a fundamental role in cancer chemotherapy, making cellular microtubules (MT), one of the few validated anticancer targets. Cancer resistance to classical MT inhibitors has motivated the development of novel molecules with increased efficacy and lower toxicity. Aiming at designing structurally-simple inhibitors of MT assembly, we synthesized a series of thirty-one 3,4,5-trimethoxy-hydrazones and twenty-five derivatives or analogs. Docking simulations suggested that a representative N-acylhydrazone could adopt an appropriate stereochemistry inside the colchicine-binding domain of tubulin. Several of these compounds showed anti-leukemia effects in the nanomolar concentration range. Interference with MT polymerization was validated by the compounds' ability to inhibit MT assembly at the biochemical and cellular level. Selective toxicity investigations done with the most potent compound, a 3,4,5-trimethoxy-hydrazone with a 1-naphthyl group, showed remarkably selective toxicity against leukemia cells in comparison with stimulated normal lymphocytes, and no acute toxicity in vivo. Finally, this molecule was as active as vincristine in a murine model of human acute lymphoblastic leukemia at a weekly dose of 1 mg/kg.

Enriched glucose and dextrin mannitol-based media modulates fibroblast behavior on bacterial cellulose membranes.

Bacterial cellulose (BC) produced by Gluconacetobacter hansenii is a suitable biopolymer for biomedical applications. In order to modulate the properties of BC and expand its use as substrate for tissue engineering mainly in the form of biomembranes, glucose or dextrin were added into a BC fermentation mannitol-based medium (BCGl and BCDe, respectively) under static culture conditions. SEM images showed effects on fiber density and porosity on both sides of the BC membranes. Both enriched media decreased the BET surface area, water holding capacity, and rehydration rate. Fourier transform infrared (attenuated total reflectance mode) spectroscopy (FTIR-ATR) analysis revealed no change in the chemical structure of BC. L929 fibroblast cells were seeded on all BC-based membranes and evaluated in aspects of cell adhesion, proliferation and morphology. BCG1 membranes showed the highest biological performance and hold promise for the use in tissue engineering applications.