Extensive H⁺release by bone substitutes affects biocompatibilityin vitrotesting

Abstract

Bone substitutes are widespread in orthopedic and trauma surgery to restore critical bony defects and/or promote local bone healing. Cell culture systems have been used for many years to screen biomaterials for their toxicity and biocompatibility. This study applies a human bone marrow cell culture system to evaluate the toxic in vitro effects of soluble components of different bone substitutes, which are already in clinical use. Different specimens of tricalcium phosphates (TCP) (Vitoss, Cerasorb), nondecalcified bovine bone (Lubboc), demineralized human bone matrices (DBM) (Grafton Flex/Putty), and collagen I/III matrix (ACI-Maix) were tested in Dulbecco's modified Eagle's medium (DMEM) and MesenCult culture solution and compared with a biomaterial-free cell culture. Biocompatibility parameters were cell viability evaluated by phase-contrast microscopy and laser flow cytometry, morphology, and the local H(+) release by bone substitutes. There were significant differences (p < 0.05) between the tested biomaterials and culture solutions. Collagen I/III, non-demineralized bovine bone, and TCP materials showed advantages for cell survival over other tested biomaterials (average values of vital cells/mL MesenCult/DMEM: Collagen I/III: 1090/1083; Vitoss: 893/483; Cerasorb: 471/523; Lubboc: 815/410; Grafton Putty: 61/44; Grafton Flex: 149/57). Especially the DBM materials lead to a significant decrease of pH, which is considered to be a major factor for cell death. DMEM culture solution supports cell survival for those bone substitutes that induce an alkaline reaction, whereas MesenCult media promotes cell vitality in biomaterials, which leads to an acidification of culture solution.

Potential effects of a low‐molecular‐weight fucoidan extracted from brown algae on bone biomaterial osteoconductive properties

“…The collagen nature of this biomaterial greatly influences osteoblastic adherence as demonstrated by Basle et al 2 These authors cultured human osteoblast-like cells (Saos-2) on two different bovine xenogenic biomaterials, which differed in matrix component, the former (Lubboc 1 ) being characterized by preservation of the mineralized collagen matrix and the latter by complete deproteinization, only the mineral phase being preserved; both were reported that the major integrin of the osteoblasts, the b1 subunit known to bind cells and collagen, was localized at the outer surface of osteoblasts in association with collagen bundles of the Lubboc, which attachment being linked to the elongated cells oriented parallel to the collagen bundles while with the deproteinized biomaterial osteoblasts appeared globular and did not adopt any preferential orientation. Our results are in accordance with this study as well as with other studies that reported on the importance of the chemical nature of a bone biomaterial for biointegration of xenogenic implants, 23 in particular, the collagenic nature of the substitute 24,25 for cells migration and proliferation. 25,26 Lubboc biomaterial containing well-integrated oriented collagen bundles as demonstrated at high magnification with electron microscopic studies [see Fig.…”

Dexamethasone modulates BMP‐2 effects on mesenchymal stem cells in vitro

“…26,27 All volunteer donors had given written consent according to the Declaration of Helsinki in its present form.…”

Bone Healing and Migration of Cord Blood—Derived Stem Cells Into a Critical Size Femoral Defect After Xenotransplantation

“…Orthovita], which had shown good cytocompatibility properties in vitro. (15) Twelve hours before xenotransplantation, USSCs were detached from culture flasks supported by 0.05% trypsin/0.02% EDTA and resuspended. A total suspension volume of each 100 l (3 × 10 7 cells/ml) was pipetted onto a 0.5 × 0.5-cm collagen I/III membrane and also onto 10 mg ␤-TCP.…”

“…(14,15,46) In addition, several other authors suggest co-administration of growth factors (e.g., BMP-2 or BMP-9) to increase the osteogenic potential of transplanted MSCs.…”