FORMULATION AND CHARACTERIZATION OF POLOXAMER 407 (R): THERMOREVERSIBLE GEL CONTAINING POLYMERIC MICROPARTICLES AND HYALURONIC ACID

The influence of the composition and preparation method on the sol-gel transition temperature (Tsol-gel) and rheological response of poloxamer-based formulations was determined. Manual and more complex mechanical stirring were found to provide similar results. In addition, a linear dependence of Tsol-gel on the poloxamer content was observed in the range of concentrations analyzed, and a Poloxamer 407® concentration of 18% was selected. The addition of hyaluronic acid did not lead to significant changes in the Tsol-gel values. In contrast, the addition of microparticles caused a reduction in Tsol-gel without a significant reduction in gel strength, and pseudoplastic characteristics were observed, indicating that a thermoreversible gel was obtained with a rheology suitable for application in the treatment of burn wounds

Nanotechnology Applied in Agriculture: Controlled Release of Agrochemicals

In the last few years, the use of nanotechnology to control environmental pollution has considerably increased. Several nanostructured or nanometric dimensional materials have been used as carrier vehicles in the controlled release of agrochemicals due to their biodegradability, low toxicity, low cost, high reproducibility, easy and fast preparation and characterization, water uptake, and reversible properties. The major advantages of these systems are the gradual, sustained, and controlled release over a long period of time, with the aim to improve agricultural and crop protection. In the case of agrochemicals, the scientific community also aims to obtain biodegradable matrices (biodegradable carrier vehicles) able to reduce the number and frequency of applications of nutrients and pesticides in the soil that would contribute to a decrease in environmental pollution and contamination by pollutants. Thus, it is evident that nanotechnology can play a decisive role in the agriculture field. However, only a few references (including papers and reviews) were found in the literature. This gap is most likely related to the short time that these nanomaterials have been studied for this specific application. With this in mind, the aim of this chapter is to collect reports about different polymeric, inorganic, and hybrid nanomatrices (nanocomposites) with great potential for applications as carrier vehicles in the controlled release of agrochemicals.Faculdade de Engenharia de Ilha Solteira, Departamento de Física e Química, UNESP – Univ Estadual PaulistaFaculdade de Engenharia de Ilha Solteira, Departamento de Física e Química, UNESP – Univ Estadual Paulist