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Porous scaffolds of gelatin–hydroxyapatite nanocomposites obtained by biomimetic approach: Characterization and antibiotic drug release
Author(s) -
Kim HaeWon,
Knowles Jonathan C.,
Kim HyounEe
Publication year - 2005
Publication title -
journal of biomedical materials research part b: applied biomaterials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.665
H-Index - 108
eISSN - 1552-4981
pISSN - 1552-4973
DOI - 10.1002/jbm.b.30236
Subject(s) - gelatin , nanocomposite , materials science , chemical engineering , drug delivery , drug carrier , porosity , composite material , chemistry , nanotechnology , organic chemistry , engineering
Gelatin–hydroxyapatite (HA) nanocomposite porous scaffolds were fabricated biomimetically, and their feasibility as a drug‐delivery carrier for tissue‐regeneration and wound‐healing treatments was addressed. The composite sols were prepared by the precipitation of HA up to 30 wt % within a gelatin solution with the use of calcium and phosphate precursors, and the porous scaffold was obtained by casting the sols and further freeze drying. The obtained bodies were crosslinked with carbodiimide derivatives to retain chemical and thermal integrity. The apatite precipitates were observed to be a poorly crystallized carbonate‐substituted HA. The nanocomposite scaffolds had porosities of ∼ 89–92% and exhibited a bimodal pore distribution, that is, the macropores (∼ 300–500 μm) of the framework structure, and micropores (∼ 0.5–1 μm) formed on the framework surface. Transmission electron microscopy (TEM) observation revealed the precipitation of highly elongated HA nanocrystals on the gelatin network. The well‐developed porous structure and organized nanocomposite configurations were in marked contrast to the directly mixed gelatin–HA powder conventional composites. For drug‐release tests, tetracycline, an antibiotic drug, was entrapped within the scaffold, and the drug‐release profile was examined with processing parameters, such as HA amount in gelatin, crosslinking degree, and initial drug addition. The drug entrapment decreased with increasing HA amount, but increased with increasing crosslinking degree and initial drug addition. The crosslinking of the gelatin was the prerequisite to sustaining and controlling the drug releases. Compared to pure gelatin, the gelatin–HA nanocomposites had lower drug releases, because of their lower water uptake and degradation. All the nanocomposite scaffolds released drugs in proportion to the initial drug addition, suggesting their capacity to deliver drugs in a controlled manner. Based on the findings of the well‐developed morphological feature and controlled drug‐release profile, the gelatin–HA nanocomposite porous scaffolds are suggested to be potentially useful for hard‐tissue regeneration. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005