Adsorbed serum albumin is permissive to macrophage attachment to perfluorocarbon polymer surfaces in culture

Abstract

Monocyte/macrophage adhesion to biomaterials, correlated with foreign body response, occurs through protein-mediated surface interactions. Albumin-selective perfluorocarbon (FC) biomaterials are generally poorly cell-conducive due to insufficient receptor-mediated surface interactions, but macrophages bind to albumin-coated substrates and also preferentially to highly hydrophobic fluorinated surfaces. Bone marrow macrophages (BMMO) and IC-21, RAW 264.7 and J774A.1 monocyte/macrophage cells were cultured on FC surfaces. Protein deposition onto two distinct FC surfaces from complex and single-component solutions was tracked using fluorescence and time-of-flight secondary ion mass spectrometry (ToF-SIMS) methods. Cell adhesion and growth on protein pre-treated substrates were compared by light microscopy. Flow cytometry and integrin-directed antibody receptor blocking assessed integrins critical for monocyte/macrophage adhesion in vitro. Albumin predominantly adsorbs onto both FC surfaces from 10% serum. In cultures pre-adsorbed with albumin or serum-dilutions, BMMO responded similar to IC-21 at early time points. Compared to Teflon® AF, plasma-polymerized FC was less permissive to extended cell proliferation. The β2 integrins play major roles in macrophage adhesion to FC surfaces: antibody blocking significantly disrupted cell adhesion. Albumin-mediated cell adhesion mechanisms to FC surfaces could not be clarified. Primary BMMO and secondary IC-21 macrophages behave similarly on FC surfaces, regardless of pre-adsorbed protein biasing, with respect to adhesion, cell morphology, motility and proliferation.

Macrophage-mediated erosion of gamma irradiated poly(trimethylene carbonate) films

“…Grainger and co-workers reported that macrophages of different origins show differences in responsiveness to chemical stimuli in terms of cytokine release, phenotype and intrinsic activation state [25,26]. Although it was suggested to use different macrophage cell lines when assessing cell-biomaterial interactions in vitro, the J774A cell line was used in this study, as the behaviour of these cells is similar to primary monocytic cells [25].…”

The modulation of dendritic cell integrin binding and activation by RGD-peptide density gradient substrates

“…After sterilization, gradient chips were washed with PBS (Hyclone) and blocked with 1% bovine serum albumin (BSA) (Fisher Bioreagents) in PBS for 1 h. Although albumin is widely used to block cell adhesion for numerous cell types, in this case it is known that DCs, like other leukocytes are proficient in adhering to albuminblocked surfaces although the mechanism has not been demonstrated [8,60]. We utilized albumin-blocked gradient substrates to support uniform numbers of adherent DCs across the length of the gradient chips.…”

Probing albumin adsorption onto calcium phosphates by x-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry

“…9 While albumins have been shown to act as blocking agents for surfaces 1, 10 (e.g., prevent platelet adhesion when fully covering a surface), 11, 12 they can also promote the adsorption of biomolecules when they change conformation on the surface. 11, 13–15 Coating of implants with hydroxyapatite (HAp), a physiological phase of calcium phosphate, is a promising strategy for artificial bone replacements and other implants. Several techniques have been proposed to prepare HAp coatings, ranging from spray-coating 16 to precipitation of the mineral from supersaturated physiological solutions.…”