1. Introduction

Hydrophilic membranes based on hydrogels can be defined as a polymeric material, which is insoluble in water, can absorb it and retain a significant fraction in its structure [1]. The material that forms the membranes with these characteristics is composed of two water-insoluble crosslinked hydrophilic polymer systems, due to the existence of a three-dimensional network connecting their chains, and is perceived that water was retained in its structure [2–4].

gel process, it is possible to obtain nanoparticles of pseudoboehmite, having as precursors

Obtaining Hydrogels based on PVP/PVAL/Chitosan Containing Pseudoboehmite Nanoparticles for Application…

http://dx.doi.org/10.5772/intechopen.72007

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The sol-gel process consists of synthesis of materials, caused by the transition of a sol system, dispersion of colloidal particles (dimension from 1 to 100 mm) in a fluid; in a gel system, rigid structure system of colloidal particles or chains polymerization by immobilizing the liquid

Pseudoboehmites obtained by the sol-gel process have been successfully used in drug delivery

The aim of this chapter is to obtain a polymer system based on PVP, PVAl and chitosan containing pseudoboehmite nanoparticles, through the action of ionizing radiation, although the excellent biomedical properties in clinical practice of PVP-based hydrogels are confirmed, the difficult handling of these materials has been observed on their poor mechanical properties. Therefore, it is important to study new systems that maintain the properties required for these materials and at the same time to implement the physical:chemical and mechanical properties

The following reagents were used: aluminum nitrate Al(NO3)3, supplied by Dinâmica LTDA; ammonium hydroxide (NH4OH), supplied by Audaz Reagente Tecnológico; polyvinyl alcohol, supplied by Bandeirante Química; poly(N-vinyl-2-pyrrolidone) (PVP), supplied by GAF Co.; chitosan, supplied by Polymar; poly(ethylene glycol), supplied by Oxiteno Brasil and agar sup-

The synthesis of nanoparticles of pseudoboehmite (PSB): The nanoparticles of the pseudoboehmite were obtained through the sol-gel process, according to Munhoz Jr. et al. [22], aluminum nitrate solution in H2O, solution of ammonium nitrate in H2O and solution of polyvinyl alcohol in H2O, which is used to increase the viscosity of the aluminum nitrate solution. The solution of aluminum nitrate and polyvinyl alcohol was mixed with the ammonium hydroxide solution. The obtained product was washed with distilled water and dried through air.

Obtaining chitosan solution: The chitosan was dissolved in acetic acid solution, 2 wt% in H2O, which was stirred for 48 h. After dissolution of chitosan, it was neutralized with 1 wt% sodium

Preparation of PVP/PVAl/PSB/chitosan membranes reinforced with PSB: Membranes with 3 wt%

The hydrogels were produced from a solution of PVP, PVAl, chitosan, agar and PEG in H2O, which was heated and subsequently PSB was added to the solution. The solution was poured

PSB were obtained. Table 1 shows the composition of the membranes obtained.

into polyethylene molds and after cooling, a physical gel was obtained.

aluminum nitrate and ammonium hydroxide [20].

phase [21].

systems [18].

2.1. Materials

plied by Oxide.

2.2. Methods

2. Experimental study

hydroxide solution in H2O until pH 7.

Hydrogels can be expanded by water and ion absorption, above the equilibrium state and retain their original shape and mechanical properties. In addition, they present permeability to biologically active substances with low molecular weight, being used in dressings directly on contact with the skin and can be used as dressing or bandage in burn wounds, vascular prostheses, artificial cartilage membranes for hemodialysis, among other applications [5, 6].

Hydrogels obtained by ionizing radiation, having as precursors poly(n-vinyl-2-pyrrolidone) (PVP), agar and plasticizing agents such as polyethylene glycol that have been used in pharmaceuticals and have advantages over the previously obtained methods, they eliminate the sterilization phase, as this is still being obtained in the process of ionizing radiation [1].

Due to its properties, PVAl is one of the synthetic polymers that are used as a biomaterial, being of great importance in the industry, mainly in cosmetics, where it is used as an additive, providing texture to the products. Its main function is that of a plasticizer. Its use in the synthesis of hydrophilic membranes presents some restrictions when used alone, because the obtained membrane presents low elasticity and rigidity. To improve these properties, it is used in conjunction with other polymers [7, 8].

Chitosan is a natural polymer that can be obtained through the process of deacetylation of chitin, a polysaccharide of great abundance in nature, and present a similar chain to cellulose. Among its main characteristics, of great importance and industrial interest, it is atoxic and has an easy way to create gel [9].

Chitosan nanocomposites have been used in the cotton coating for application in dressings and bandage with the purpose of increasing the absorption of the exudate as well as improving the antibacterial activity [10].

Chitosan and PVAl are biocompatible polymers being in the composition of several hydrogels used today [11, 12]. Hydrophilic membranes based on PVAl and chitosan have been synthesized because the presence of chitosan improves the mechanical, hydrophilic and antibacterial properties of membranes obtained from PVAl [13, 14]. These membranes modified by the presence of nanoclays for use in dressings have been obtained with good mechanical and absorption properties [15, 16].

Hydrophilic membranes obtained from polyvinyl alcohol, poly(N-vinylpyrrolidone) and antibiotic containing chitosan have been synthesized by Yu et al. [17].

The pseudoboehmite obtained by the sol-gel process is a ceramic nanoparticle with high surface area, bioinert, which can be used in drug delivery systems [18]. Pseudoboehmite has the same structure as the boehmite (ɣ-ALOOH). It has an orthorhombic structure and presents two layers of octahedral oxygen partially filled with aluminum cations [19]. Through the sol: gel process, it is possible to obtain nanoparticles of pseudoboehmite, having as precursors aluminum nitrate and ammonium hydroxide [20].

The sol-gel process consists of synthesis of materials, caused by the transition of a sol system, dispersion of colloidal particles (dimension from 1 to 100 mm) in a fluid; in a gel system, rigid structure system of colloidal particles or chains polymerization by immobilizing the liquid phase [21].

Pseudoboehmites obtained by the sol-gel process have been successfully used in drug delivery systems [18].

The aim of this chapter is to obtain a polymer system based on PVP, PVAl and chitosan containing pseudoboehmite nanoparticles, through the action of ionizing radiation, although the excellent biomedical properties in clinical practice of PVP-based hydrogels are confirmed, the difficult handling of these materials has been observed on their poor mechanical properties. Therefore, it is important to study new systems that maintain the properties required for these materials and at the same time to implement the physical:chemical and mechanical properties
