In vitro evaluation of 5-Fluorouracil release by microspheres based on chitosan / Montmorillonite/ Avaliação in vitro da libertação de 5-Fluorouracil por microesferas à base de quitosano / Montmorilonite

5-fluorouracil (5-FU) is one of the most widely used chemotherapeutic compounds for cancer treatment and its rapid metabolization and non-uniform oral absorption are the limitations for its use as an oral chemotherapy. Therefore, this study was performed to evaluate the influence of a 5-fluorouracil (5-FU) nanocomposite microspheres with different diameters to test on a controlled release system in the gastrointestinal environment. 5-FU was incorporated into the chitosan/montmorillonite nanocomposite microspheres through the intercalation method. The microspheres containing the 5-FU were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and optical microscopy (OM). In vitro release fractions at different pHs (1.2, 7.4 and 10.0) were investigated by UV-vis spectroscopy. The release profile of 5-FU for the systems studied was adjusted through the Korsmeyer-Peppas kinetic model, and the results suggested that the mechanism of controlled release at pH 7.4 and 10 occurs by diffusion. In addition, the 5-FU microspheres diameter and roughness directly interfere with the release rate and the released fraction, since the F1 / F2 systems showed a difference in the released fraction of 5-FU of 7.97% and for the systems F3 / F4 the difference was 2.86%. The prepared F1, F2, F3 and F4 systems are suitable for delivery of 5-FU to the gastrointestinal environment in a controlled manner

Inexpensive Apparatus for Fabricating Microspheres for 5-Fluorouracil Controlled Release Systems

The aim of this study was to develop an inexpensive apparatus for fabricating microspheres, based on chitosan, for 5-fluorouracil (5-FU) controlled release. Chitosan microspheres were prepared by precipitation method and the effects of manufacturing parameters (injection and airflow rates) on size distribution microspheres were analyzed by optical and scanning electron microscopy. The results show that the manufacturing parameters, injection and airflow rates, determine the microsphere size distribution. By modulating these parameters, it was possible to produce chitosan microspheres as small as 437 ± 44 μm and as large as 993 ± 18 μm. Chitosan microspheres loaded with 5-FU were also produced using the experimental equipment. The obtained microspheres presented 5-FU controlled release, indicating that the microspheres can be used orally, since they are capable of crossing the stomach barrier and of continuing with the process of 5-FU release

JATROPHA MOLLISSIMA EXTRACT WITH CHITOSAN/COLLAGEN SCAFFOLDS AND THEIR BIODEGRADABILITY EVALUATION

Scaffolds are devices with interconnected pores that favor cell interaction and proliferation. They play a significant role in tissue engineering, as they mimic the conditions of tissue production in vivo. The aim of this study was to synthesize scaffolds of chitosan, collagen, and Jatropha mollissima by lyophilization and characterize their chemical/biodegradability and morphological properties. For that, techniques of optical microscopy, infrared spectrometry, biodegradation test, and degree of swelling were performed. A 2% (m/v) chitosan/collagen (1:9) in lactic acid solution was produced. Then, Jatropha mollissima crude extract was added to this solution in different proportions of mass (5, 10, and 15%). Optical microscope images indicated the three-dimensional network formation with interconnected pores and predominantly lamellar shape. Through infrared spectrometry, characteristic bands indicated a physical mixture. Also, the swelling degree of all samples was proportional to the amount of Jatropha mollissima extract with the highest percentage of 1852%. Biodegradation test also revealed a proportional ratio between the amount of sap used and the degraded percentage with the lowest value of around 35% in 28 days. In conclusion, it can be inferred that the scaffolds produced show potential to be used in tissue engineering as dressings