Low-cost processing technology for the synthesis of calcium phosphates/collagen biocomposites for potential bone tissue engineering applications

Abstract

In the present study two novel composites of Calcium phosphates (CaP) and Collagen (COL) were synthesized, hydroxyapatite/Collagen (HA/COL) and hydroxyapatite-btricalcium phosphate/COL (HAbTCP/COL). Collagen was extracted from bovine pericardium submitted to enzymatic digestion and purification by ion-exchange chromatography yielding high purity grade type I collagen. Biocomposites of HAP/COL and HAbTCP/COL were produced with a calcium phosphate/COL ratio of 80/20 (wt. (%)) and were characterized by chemical analysis, light microscopy and scanning electron microscopy, X ray diffraction and FT-infrared spectroscopy. SEM results of the CaP powders showed agglomerates of particles at the nanometric size range with predominantly columnar shape and average chemical composition of [Ca/P] = 1.67. FTIR analysis of collagen has confirmed the major vibrational bands associated with chemical groups like amides and hydroxyls usually found in proteins. SEM micrographs have indicated that both morphological and structural features and chemical composition of the composites were very similar to their precursors, collagen and calcium phosphate components. SDS-PAGE characterization results of protein extracted and purified has showed that bovine type I collagen was successfully obtained. Finally, the biocomposites presented a homogeneous aspect with the calcium phosphate particles aggregated to the collagen fibers. Hence, the novel developed biocomposites have high potential to be used for rebuilding small lesions in bone tissue engineering

Organic/Inorganic bioactive materials Part II: in vitro bioactivity of Collagen-Calcium Phosphate Silicate/Wollastonite hybrids

“…3a), the amide I peak, centered at 1656 cm -1 predominantly corresponds to the C=O stretch vibration [31,41]. In additional studies [26,41] the amide I band in a bone spectrum is representative of the collagen content and structure. The amide II, positioned at 1550 cm -1 , corresponds to a combination of the N-H in-plane bend and the C-H stretch vibrations [26].…”

“…For the amide III bands there are two bands assigned at 1241 and 1281 cm -1 . The amide III peaks corresponds to a combination of the C-N stretch and the N-H in-plane bends [31,41]. Amide B is centered at 3081 cm -1 [31,41,68].…”

“…The amide III peaks corresponds to a combination of the C-N stretch and the N-H in-plane bends [31,41]. Amide B is centered at 3081 cm -1 [31,41,68]. Two additional bands, visible at 1399 and 1340 cm -1 , can be attributed to the presence of COOH and COO -in the spectrum of pure collagen and pure gelatin [69].…”

“…CPS/W (Fig. 7b) shows a visibly porous structure, which is a characteristic for silicon containing apatites [41]. When collagen was mixed CPS/W in 75:25 wt.%, SEM images ( Fig.…”

“…Other authors studied the possibility to produce bioactive materials between biphasic Hydroxyapatite/ Tricalcium Phospate (HA/TCP) ceramics and type I collagen for filling intramedullary cavities remaining after tumor excision [38], dehiscence-type defects in dogs [39], bone tissue regeneration [40] and rebuilding small lesions in bone tissue engineering [41].…”