Carboxymethylcellulose hydrogels crosslinked with keratin nanoparticles for efficient prednisolone delivery.

Carboxymethylcellulose (CMC) and keratin nanoparticle (KNP) hydrogels were obtained, characterized, and applied as drug delivery systems (DDSs) for the first time. Lyophilized CMC/KNP mixtures containing 10, 25, and 50 wt% of KNPs were kept at 170 °C for 90 min to crosslink CMC chains through a solid-state reaction with the KNPs. The hydrogels were characterized by infrared spectroscopy, thermal analyses, X-ray diffraction, mechanical measurements, and scanning electron microscopy. The infrared spectra indicated the formation of ester and amide linkages between crosslinked CMC and KNPs. The elastic modulus of the hydrogel containing 10 wt% KNPs was 2-fold higher than that of the hydrogel containing 50 wt% KNPs. The mechanical properties influenced the hydrogel stability and water uptake. The anti-inflammatory prednisolone (PRED) drug was incorporated into the hydrogels, and the release mechanism was investigated. The hydrogels supported PRED release by drug desorption for approximately 360 h. A sustained release mechanism was achieved. The CMC/KNP and CMC/KNP/PRED hydrogels were cytocompatible toward mammalian cells. The CMC/KNP/PRED set imparted the highest cell viability after 7 days of incubation. This study showed a straightforward procedure to create DDSs (chemically crosslinked) based on polysaccharides and proteins for efficient PRED delivery.

Shelf-life of guavas coated with biodegradable starch and cellulose-based films.

Guava is a perishable fruit susceptible to post-harvest losses. So, the development of biodegradable films based on acetylated cassava starch (ACS) and hydroxyethyl cellulose (HEC) could be an alternative to increase guavas (Psidium guajava L.) shelf life. Films were characterized by solubility, opacity, water vapor transport, and thickness. Mass loss, texture, titratable acidity, soluble solids, vitamin C, and skin color of the fruits were analyzed. The films with higher HEC concentration were more transparent and hygroscopic. Guava coated with 75% HEC and 25% ACS or 100% HEC films increased firmness, maintained green skin color and reduced ripeness, lasting for 13 days, ensuring that the ACS and HEC based films can increase guavas shelf life, besides decrease environmental impacts of non-biodegradable packages.

Synthesis and characterization of a low solubility edible film based on native cassava starch.

Films based on cassava starch have been widely used for fruit coating; however, it is necessary to incorporate other polymers in order to improve mechanical properties, once starch only leads to highly hydrophilic films, compromising their application. In this way, a polymeric blend based on cassava starch, chitosan and gelatin was combined with a plasticizer to produce biodegradable films with satisfactory mechanical and barrier properties, in order to be used as fruit coating. The films were prepared by casting method and a statistical design of 23 was used to evaluate the effect of each polymer and what their combinations would influence over the final product. The formation of a physical blend was confirmed by FTIR. It showed low solubility, varying (10 ±â€¯2) % a (23 ±â€¯4) %, Opacity ranging from (1.06 ±â€¯0.04) to (1.55 ±â€¯0.13) AU x nm/mm, thickness from (0.20 ±â€¯0.01) mm to (0.44 ±â€¯0.03) mm and water vapor transmission rate ranging from 25 ±â€¯0.2 to 30 ±â€¯1.4 g s-1 m-2. Lower amounts of starch led to more flexible, less opaque and soluble films, while the combination of higher levels of starch and chitosan was responsible for lowering films water vapor transmission rate. Thus, the films showed interesting properties for fruit surface coating.