Dados do Trabalho

Título/Title/Titulo

Properties of Chitosan Chloride Modified with Calcium Nanophosphate Complex

Introdução/Introduction/Introdución

The compositions of chitosan and calcium phosphates are formed from the joining of two or more organic and / or inorganic materials, which give the structure favorable characteristic to develop biomaterials. Among many characteristics, we highlight the bioactivity, biodegradability and biocompatibility with human tissues.
The chemical characteristics of chitosan, calcium β-triphosphate and hydroxyapatite indicate the possibility of obtaining chitosan hydrochloride complex modified with bi-component nano ceramic.

Objetivos - Metodologia - Resultados - Discussão dos Resultados/Objectives - Methodology - Results - Discussion of Results/Objetivos - Metodología - Resultados - Discusión de los resultados

OBJECTIVES:

Biocomposite development of bi-component chitosan as biomaterial alternative applied to regenerative medicine and tissue engineering.

METHODOLOGY:

Initially, the solution of chitosan hydrochloride with a polymer content of 2% (m/ m) was prepared in a solution of 2L of 0.9% HCl solution (v/v). The salt-making process occurs by constant stirring performed by a mixer at room temperature (25 °C). Three solutions (A, B and C) were prepared. In solution A was added 2% (m/m) of β-TCP, in solution B 0.5% (m/m) of HAp and solution C was obtained from the mixture of solutions A and B, having the following composition: 2% (m/m) of β-TCP and 0.5% (m/m) of HAp. It is noted that the polymer concentration and HCl content of all solutions were maintained unchanged, that is, 2% (m/m) polymer and 0.9% (v/v) acid.
After obtaining the solutions, they underwent the following quantitative and qualitative analyzes:
- Fourier-transform infrared spectroscopy (FTIR);
- Particle size determination of commercial β-TCP and HAp;
- Scanning electron microscopy (SEM) study of commercial calcium phosphate particulates;
- Determination of particle size and Zeta potential of calcium phosphates in chitosan solution.

RESULTS AND DISCUSSIONS:

The FTIR and SEM analyzes indicate that the morphologies of the powders differ in shape. It also showed that they have great agglomeration capacity.

Particle size analysis of commercial calcium phosphates indicated the presence of about 10% of phosphate particles at the nanoscale.

The chitosan dissolution process using a solution of β - TCP microparticles dissolved with 0.9% HCl reduced the number of β - TCP particles to the nano size, resulting in a solution of chitosan / β - TCP hydrochloride salt in nanoparticles, suggesting a strong ionic interaction between the calcium phosphate and the chitosan amine groups, generating a bi-component nano ceramic. The analyzes also indicate that hydroxyapatite is less soluble than β - TCP.

The solution with the smallest particle size and stability was solution C, which had a range of 12.8 - 58 nm and a zeta potential of 52.9 ± 4.0 mV.

Considerações Finais/Final considerations/Consideraciones finales

It was observed that, by adding β-TCP to the chitosan solution, the phosphate passed from micro-scale to nano;
During mixing of the HAp and β-TCP particles contained in the chitosan solution the HAp particles immediately dissolved, resulting in a clear solution showing a great stability and a beneficial effect by the size of the nanoparticles within a range of 12.8-58.0 nm;
This work showed a new method of obtaining solutions of chitosan hydrochloride with nano ceramic using hydroxyapatite and micro - size β - TCP.

Palavras-chave/Key words/Palabras clave

Chitosan; chitosan salt; calcium phosphate; functional biopolymer; medical applications.