Mechanobiologically induced bone-like nodules: Matrix characterization from micro to nanoscale

Abstract

In bone tissue engineering, stem cells are known to form inhomogeneous bone-like nodules on a micrometric scale. Herein, micro-and nano-infrared (IR) micro-spectroscopies were used to decipher the chemical composition of the bone-like nodule. Histological and immunohistochemical analyses revealed a cohesive tissue with bone-markers positive cells surrounded by dense mineralized type-I collagen. Micro-IR gathered complementary information indicating a nonmature collagen at the top and periphery and a mature collagen within the nodule. Atomic force microscopy combined to IR (AFM-IR) analyses showed distinct spectra of "cell" and "collagen" rich areas. In contrast to the "cell" area, spectra of "collagen" area revealed the presence of carbohydrate moieties of collagen and/or the presence of glycoproteins. However, it was not possible to determine the collagen maturity, due to strong bands overlapping and/or possible protein orientation effects. Such findings could help developing protocols to allow a reliable characterization of in vitro generated complex bone tissues.

Vapor-phased fabrication and modulation of cell-laden scaffolding materials

“…The independent and distinct biological activities detected in compartments A and B resulted from the cell differentiations in the corresponding compartments, which supported the hypothesis. Specifically, in compartment A, the formed bone-like nodules 43 were composed of COL-I-positive MG-63 cells, indicating vital osteogenic activity. At day 7, the cell density varied from 11 to 18 cells per nodule with an average size of 175 ± 22 µm.…”

Review on near-field detection technology in the biomedical field

“…Bildstein et al 81 used resonanceenhanced mode AFM-IR to localize the lipid distribution in hair. The heterogeneity between tissues, including kidney deposits, 82 different skin layers, 83 osteoid nodules, 84 and sorghum stem wax, 85 could be revealed using infrared near-field techniques. Esteve et al 82 carried out AFM-IR spectral analysis of abnormal deposits in the kidney and acquired their chemical composition, including pure vancomycin and organic materials with phosphate.…”

“…Kemel et al 83 obtained chemical components of different skin layers using AFM-IR. Rammal et al 84 used AFM-IR for precise chemical composition analysis of bone-like nodules. They found clear spectral differences between the cell-rich and collagen-rich regions.…”

“…They found clear spectral differences between the cell-rich and collagen-rich regions. 84 Farber et al 85 used AFM-IR to assess the heterogeneity of internal and external chemical components of sorghum stem wax.…”

“…used AFM-IR for precise chemical composition analysis of bone-like nodules. They found clear spectral differences between the cell-rich and collagen-rich regions 84 . Farber et al 85 .…”