Antibody Immobilization on Sulfated Cellulose Nanocrystals.

Exploiting cellulose nanocrystals' high aspect ratio and tailorable surface for immunological biosensors has been hindered by the relatively limited research on using commonly available sulfated cellulose nanocrystals (CNCs) for antibody immobilization and by the low hydrolytic stability of dried assemblies produced from sulfated CNCs. Herein, we report a reaction scheme that enables both hydrolytic stability and antibody immobilization through 3-aminopropyl-triethoxysilane and glutaric anhydride chemistry. Immobilization was demonstrated using three model antibodies used in the detection of the cancer biomarkers: alpha-fetoprotein, prostate-specific antigen, and carcinoembryonic antigen. Thermogravimetric analysis coupled with Fourier-transform infrared spectroscopy provided evidence of CNC modification. Quartz crystal microbalance with dissipation monitoring was used to monitor binding during each step of the immobilization scheme as well as binding of the corresponding antigens. The general reaction scheme was tested using both aqueous CNC dispersions and CNC films. Film modification is slightly simpler as it avoids centrifugation and washing steps. However, modifying the dispersed CNCs provides access to their entire surface area and results in a greater capacity for antigen binding.

5-Fluorouracil drug delivery system based on bacterial nanocellulose for colorectal cancer treatment: Mathematical and in vitro evaluation.

Colorectal cancer (CRC) is the third most common worldwide. Its treatment includes adjuvant chemotherapy with 5-fluorouracil (5FU) administered intravenously. 5FU is an antineoplastic drug of the fluoropyrimidines group, widely used in the treatment of solid tumors, mainly CRC. Nevertheless, it causes several adverse effects and poor effectiveness due to its short half-life. This work aimed to employ bacterial nanocellulose (BNC) as an encapsulation material for the oral administration of 5FU. First, the adsorption phenomena were analyzed by isotherms, thermodynamic parameters, and kinetic models. Then, encapsulation was carried out using spray-drying, and encapsulated 5FU desorption profiles were assessed in simulated fluids. The biological behavior was evaluated on colon cancer SW480 and SW620 cell lines. As result, it was found that at 25 °C a monolayer of 5FU was formed and the process showed to be the most spontaneous one. In the characterization of the nanocapsules, important changes were detected by the presence of 5FU. The delivery in the colon corresponded to a controlled release behavior. The in vitro assay indicated an improvement in the toxicity effect of the drug and its mechanism of action. Accordingly, BNC is a promising biomaterial for the development of a colon drug delivery platform of 5FU.

Cellulose-Cyclodextrin Co-Polymer for the Removal of Cyanotoxins on Water Sources.

With increasing global water temperatures and nutrient runoff in recent decades, the blooming season of algae lasts longer, resulting in toxin concentrations that exceed safe limits for human consumption and for recreational use. From the different toxins, microcystin-LR has been reported as the main cyanotoxin related to liver cancer, and consequently its abundance in water is constantly monitored. In this work, we report a methodology for decorating cellulose nanofibrils with ß-cyclodextrin or with poly(ß-cyclodextrin) which were tested for the recovery of microcystin from synthetic water. The adsorption was followed by Quartz Crystal Microbalance with Dissipation monitoring (QCM-D), allowing for real-time monitoring of the adsorption behavior. A maximum recovery of 196 mg/g was obtained with the modified by cyclodextrin. Characterization of the modified substrate was confirmed with Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Photoelectron Spectroscopy (XPS), Thermogravimetric Analysis (TGA), and Atomic Force Microscopy (AFM).