Chitosan calcium phosphate
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2022
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CONGRESSO BRASILEIRO DE ENGENHARIA E CIÊNCIA DOS MATERIAIS, 24.
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Resumo
Osseous reconstruction is a problem of interest for tissue engineering. One approach applied on
this issue is the development of biomaterials used to induce osseointegration during osseous
repair process, comprising materials from calcium phosphate bone cements to many different
phosphorous-containing polymers. The incorporation of phosphorous-containing groups into
natural or synthetic polymers as a way to induce the inorganic crystal nucleation and growth and to
control its microstructure is an attempt to mimic the function of the organic phase of osseous
tissues and promote bone tissue formation. In this study we analyze the effect of chitosan-calcium
phosphate (CCP) salt on the mineralization of scaffolds of chitosan (CH). CH was extracted from
squid pens and solubilized at 1% in H3PO4 9.4 mol L-1 and stirred for 1h (60ºC) to produce CCP.
Then CCP was precipitated with CaCO3 until neutrality, washed with ethanol and dried at 50°C. The
product was a yellowish solid soluble in water. A 1% CH solution was prepared by dissolution in 1%
acetic acid. Chitosan/chitosan-calcium phosphate (CHCCP) gels were prepared by mixing 2.0 g of
1% CH solution to 0, 5 and 10 mg of CCP under stirring for 3 h, resulting respectively in CHCCP0,
CHCCP5 and CHCCP10. Scaffolds were prepared by freeze-drying and the mineralization process
was carried out by alternating soaking in 0.2 mol L-1 CaCl2 solution buffered with 0.05 mol L-1 Tris
(pH 7.4) and 0.12 mol L-1 Na2HPO4 solution buffered with 0.05 mol L-1 Tris (pH 9.0) at 37°C for 30
minutes each, rinsing with water between the changes and repeating these cycle six times. CH and
CHCCP5 before and after mineralization were analyzed by Fourier Transform Infrared spectroscopy.
Scaffolds before and after mineralization were analyzed by thermogravimetric analysis and
scanning electron microscope (SEM). The CH spectrum showed typical bands for this polymer, such
as the O-H stretching band in 3400 cm-1 and the amide I (C=O stretching) at 1657 cm-1, bands
also found in CHCCP5 spectra. A P-OH stretching band was observed at 571 and 561 cm-1 for
CHCCP before and after mineralization, respectively, indicating the inclusion of phosphate groups
in CH. Thermal behavior of scaffolds was characterized by three stages of mass loss; the first one
(25-200°C) is associated with release of water and is higher with CCP, the second one (200–380°C)
is due to degradation of CH structure and the third stage (380–650°C) is related to the
carbonization of polymer. The residue values obtained at 750°C were used to determine the
inorganic material contents produced in the mineralization, which were 28.4, 30.2 and 31.4% for
CHCCP0, CHCCP5 and CHCCP10, respectively. These values indicate that the presence of CCP did
not substantially increase the mineralization efficiency. SEM results showed fully mineralized
surfaces with spherical aggregates, which presents a morphology of needle-like, a shape commonly
observed in crystalline apatites.
Como referenciar
RODRIGUES, M.A.; MARTINS, V.C.; LUGAO, A.B.; PLEPIS, A.d. Chitosan calcium phosphate: an attempt to induce chitosan scaffolds mineralization. In: CONGRESSO BRASILEIRO DE ENGENHARIA E CIÊNCIA DOS MATERIAIS, 24., 6-10 de novembro, 2022, Águas de Lindóia, SP. Resumo... Disponível em: http://repositorio.ipen.br/handle/123456789/33749. Acesso em: 04 Mar 2025.
Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.