Preparation and characterization of collagen‐nanohydroxyapatite biocomposite scaffolds by cryogelation method for bone tissue engineering applications

Abstract

Recent efforts of bone repair focus on development of porous scaffolds for cell adhesion and proliferation. Collagen-nanohydroxyapatite (HA) scaffolds (70:30; 50:50; and 30:70 mass percentage) were produced by cryogelation technique using 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide hydrochloride/N-hydroxysuccinimide as crosslinking agents. A pure collagen scaffold was used as control. Morphology analysis revealed that all cryogels had highly porous structure with interconnective porosity and the nanoHA aggregates were randomly dispersed throughout the scaffold structure. Chemical analysis showed the presence of all major peaks related to collagen and HA in the biocomposites and indicated possible interaction between nanoHA aggregates and collagen molecules. Porosity analysis revealed an enhancement in the surface area as the nanoHA percentage increased in the collagen structure. The biocomposites showed improved mechanical properties as the nanoHA content increased in the scaffold. As expected, the swelling capacity decreased with the increase of nanoHA content. In vitro studies with osteoblasts cells showed that they were able to attach and spread in all cryogels surfaces. The presence of collagen-nanoHA biocomposites resulted in higher overall cellular proliferation compared to pure collagen scaffold. A statistically significant difference between collagen and collagen-nanoHA cryogels was observed after 21 day of cell culture. These innovative collagen-nanoHA cryogels could have potentially appealing application as scaffolds for bone regeneration.

Synergistic intrafibrillar/extrafibrillar mineralization of collagen scaffolds based on a biomimetic strategy to promote the regeneration of bone defects

“…Then the scaffolds were soaked in normal saline for 10,20,30,40,50,60,70, and 80 minutes at 37°C and weighed at different time points (W w ). The swelling ratio was calculated using the formula:…”

“…[1][2][3][4][5][6][7] Among these biomaterials, type 1 9 To date, mixing collagen with minerals and mineralizing collagen have been used to modify collagen scaffolds for simulating the composition and microstructure of bone tissue to the greatest extent possible. [10][11][12][13][14][15][16][17] Because HA is a primary mineral component of natural bone and possesses outstanding bioactivity, osteoconductivity, biocompatibility with bone cells, good mechanical properties, and a slow degradation rate in vivo, it has often been the first choice for modifying collagen scaffolds. 10,[18][19][20] Although directly mixing collagen with HA powders in certain proportions can result in collagen scaffolds with compositions similar to those of natural bone tissues, it is difficult to simulate their microstructure and microenvironment via this process.…”

“…[10][11][12][13][14][15][16][17] Because HA is a primary mineral component of natural bone and possesses outstanding bioactivity, osteoconductivity, biocompatibility with bone cells, good mechanical properties, and a slow degradation rate in vivo, it has often been the first choice for modifying collagen scaffolds. 10,[18][19][20] Although directly mixing collagen with HA powders in certain proportions can result in collagen scaffolds with compositions similar to those of natural bone tissues, it is difficult to simulate their microstructure and microenvironment via this process. Therefore, to solve the aforementioned problems, researchers are devoting more attention to the biomimetic mineralization of collagen scaffolds.…”

“…10,49,62,63 All the results of experiments in vitro indicated that the BMC scaffolds can provide more abundant spaces and a more suitable microenvironment to promote the proliferation and differentiation of 3T3-E1.…”

Taking a deep look: modern microscopy technologies to optimize the design and functionality of biocompatible scaffolds for tissue engineering in regenerative medicine

“…Fibre length is an important parameter of hydrogel rheological properties and for optimizing cell growth in hydrogels. We have also produced and imaged freeze-dried scaffolds (sponges, foams) from collagen I with and without micrometre-sized Bioglass, which can be crosslinked and seeded with target cells [151][152][153]. We obtained rsif.royalsocietypublishing.org J R Soc Interface 10: 20130263 SHG images from these scaffolds ( figure 7b(i)) and by using three-dimensional stacks and reconstructions, it was possible to characterize the scaffolds porous structure (not shown [12,76,141,154], silk [119], gelatin/ collagen gels [13,137] or PHB/PHBHHx [155].…”