In Vitro Biological Evaluation of 3-D Hydroxyapatite/Collagen (50/50 wt. (%)) Scaffolds

Abstract

Hydroxyapatite-collagen (HA/Col) composites are potential scaffolds for bone tissue engineering. In this work, three-dimensional (3-D) HA/Col (50/50 wt. (%)) scaffolds were synthesized using a selfassembly method and cross-linked with a 0.125% glutaraldehyde solution. Scaffolds were evaluated in vitro by cytotoxicity testing using MC3T3 cells; proliferation and differentiation were studied using STRO-1A human stromal cells for up to 21 days. Morphological and histological examinations showed a fibrous structure with a good distribution and homogeneous HA particles distribution. By thermogravimetric analysis, a ratio of 1.2 between inorganic and organic phase was found. The scaffolds presented no cytotoxicity when evaluated using three different parameters of cell survival and integrity: 2,3-bis[2-methyloxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide (XTT), Neutral Red (NR) and Crystal Violet Dye Elution (CVDE). STRO-1A cells were found to adhere, proliferate and differentiate on the 3-D scaffold, but limited cell penetration was observed.

Role of culture conditions on in vitro transformation and cellular colonization of biomimetic HA-Col scaffolds

“…A positive effect on cell adhesion and proliferation on 3D HA-organic composites has been observed when compared with HA or TCP ceramics 1 - 4 , 12 - 14 . When Col fibers were mineralised by calcium phosphate crystals, several improvements in cell adhesion occurred, because osteoblast-like cells are highly dependent on organic/inorganic chemical composition, micro/nano morphology and surface charge of the material 1 - 4 . Similarly, we observed an excellent adhesion of STRO-1A cells on mineralised Col fibers 4 and the adequate macroporosity of HA-col scaffolds (Fig.…”

“…Increasing cell seeding efficiency and uniform cell distribution in 3-D scaffold materials might result in decreased time for a total scaffold colonization by bone tissue after implantation, accelerating the recovery of patients 8 . A positive effect on cell adhesion and proliferation on 3D HA-organic composites has been observed when compared with HA or TCP ceramics 1 - 4 , 12 - 14 . When Col fibers were mineralised by calcium phosphate crystals, several improvements in cell adhesion occurred, because osteoblast-like cells are highly dependent on organic/inorganic chemical composition, micro/nano morphology and surface charge of the material 1 - 4 .…”

“…In particular, composites associating collagen and calcium phosphate have been tested for bone replacement and have shown good efficiency in vitro and in vivo 1 - 3 . We have recently developed new 3D hydroxyapatite/collagen (50/50 wt.%) scaffolds using a biomimetic synthesis approach 4 . The first in vitro biocompatibility tests we performed in static culture conditions showed a limited cell colonization and survival inside the scaffolds 4 .…”

“…We have recently developed new 3D hydroxyapatite/collagen (50/50 wt.%) scaffolds using a biomimetic synthesis approach 4 . The first in vitro biocompatibility tests we performed in static culture conditions showed a limited cell colonization and survival inside the scaffolds 4 . Dynamic culture systems are known to improve nutrient delivery and waste removal from 3D culture in porous scaffolds 5 .…”

Bioceramic Scaffolds

“…The results show that no cytotoxicity was observed in the scaffold by MC3T3 cells. STRO-1A cells were found to adhere, proliferate, and differentiate on the 3-D scaffold, but limited cell penetration was observed [127].…”