Foreign Body Giant Cell Formation Research Articles

Spatial regulation and surface chemistry control of monocyte/macrophage adhesion and foreign body giant cell formation by photochemically micropatterned surfaces.

A long-standing goal of biomedical device development has been the generation of specific, desired host blood and tissue responses. An approach to meeting this design criteria is precise surface modification that creates micropatterns of distinct physicochemical character to direct cell adhesion and behavior. For this study, poly(ethylene terephthalate) films were coated with poly(benzyl N, N-diethyldithiocarbamate-co-styrene) and sequentially exposed to monomer solutions for photoirradiation. A photomask was placed over different regions to generate micropatterned surfaces with graft polymer stripes of three distinct ionic characters. Human monocytes were cultured on these surfaces to ascertain whether adhesion and fusion of monocytes/macrophages could be controlled. Nonionic polyacrylamide greatly inhibited adhesion and induced clumping of the few monocytes that did adhere. Macrophage adhesion and spreading led to high degrees of interleukin-13 induced foreign body giant cell formation on both the anionic poly(acrylic acid), sodium salt, and benzyl N,N-diethyldithiocarbamate portions of the culture surface. In spite of the highest observed levels of monocyte/macrophage adhesion on cationic poly(dimethylaminopropylacrylamide), methiodide, the adherent cells were not competent to undergo fusion to form foreign body giant cells. These results suggest that inflammatory cell responses may be spatially controlled in a manner that may be ultimately exploited to improve the biocompatibility of medical devices.

Effects of surface-coupled polyethylene oxide on human macrophage adhesion and foreign body giant cell formation in vitro.

Surface immobilized polyethylene oxide (PEO) has been shown to efficiently reduce protein adsorption and cellular adhesion, resulting in a biologically passive surface. To explore the in vitro effects of surface immobilized PEO on the human inflammatory cells, macrophages, and foreign body giant cells (FBGCs), we developed a diisocyanate-based method for coupling PEO to amine-modified glass, a surface previously shown to enhance macrophage adhesion and FBGC formation. Contact angle analysis and X-ray photoelectron spectroscopy confirmed the presence of PEO molecules bound to the surface and revealed that PEO molecular weight significantly influenced the efficiency of PEO coupling. We used a 10-day human monocyte culture protocol to demonstrate that the presence of surface coupled PEO molecules does not significantly decrease initial monocyte density or monocyte-derived macrophage density after 3 days. However, PEO-coupled surfaces significantly reduced long-term monocyte-derived macrophage density and virtually eliminated interleukin-4-induced FBGC formation observed at day 10. The cellular response to these PEO-coupled surfaces was related to the molecular weight of the PEO chains, which was varied between 200 Da and 18.5 kDa. These results suggest that an optimized PEO surface treatment may be effective in reducing inflammatory cell adhesion and possible degradation during the inflammatory response to an implanted biomedical device.

Monocyte, macrophage and foreign body giant cell interactions with molecularly engineered surfaces.

To elucidate the mechanisms involved in monocyte/macrophage adhesion and fusion to form foreign body giant cells on molecularly engineered surfaces, we have utilized our in vitro culture system to examine surface chemistry effects, cytoskeletal reorganization and adhesive structure development, and cell receptor-ligand interactions in in vitro foreign body giant cell formation. Utilizing silane-modified surfaces, monocyte/macrophage adhesion was essentially unaffected by surface chemistry, however the density of foreign body giant cells (FBGCs) was correlated with surface carbon content. An exception to the surface-independent macrophage adhesion were the alkyl-silane modified surfaces which exhibited reduced adhesion and FBGC formation. Utilizing confocal immunofluorescent techniques, cytoskeletal reorganization and adhesive structure development in in vitro FBGC formation was studied. Podosomes were identified as the adhesive structures in macrophages and FBGCs based on the presence of characteristic cytoplasmic proteins and F-actin at the ventral cell surface. Focal adhesion kinase (FAK) and focal adhesions were not identified as the adhesive structures in macrophages and FBGCs. In studying the effect of preadsorbed proteins on FBGC formation, fibronectin or vitronectin do not play major roles in initial monocyte/macrophage adhesion, whereas polystyrene surfaces modified with RGD exhibited significant FBGC formation. These studies identify the potential importance of surface chemistry-dependent conformational alterations which may occur in proteins adsorbed to surfaces and their potential involvement in receptor-ligand interactions. Significantly, preadsorption of alpha2-macroglobulin facilitated macrophage fusion and FBGC formation readily on the RGD surface in the absence of any additional serum proteins. As alpha2-macroglobulin receptors are not found on blood monocytes but are expressed only with macrophage development, these results point to a potential interaction between adsorbed 2-macroglobulin and its receptors on macrophages during macrophage development and fusion. These studies identify important surface independent and dependent effects in foreign body reaction development that may be important in the identification of biological design criteria for molecularly engineered surfaces and tissue engineered devices.

Direct activation of mast cells by prosthetic biomaterial particles.

IL-4 is a mast cell and T cell produced immune cytokine that is important in the regulation of macrophage function. IL-4 has also been implicated in the induction of foreign body giant cell formation. In patients with long-term joint prostheses, a localized granulomatous inflammation develops in periarticular tissues and other organs where phagocytosis of particulate material from various prosthetic components takes place. In this study we used the inflammatory lesions of the bone-implant interface as a model to investigate the possible production, the frequency and the cellular source of IL-4. 40 samples of the interface membrane obtained from 25 patients undergoing revision of clinically failed implants were analyzed by immunohistochemistry. Cryostat sections were labeled with specific monoclonal antibodies to mast cell products: IL-4, tryptase and the receptor c-kit (CD117). The study has identified a significant level of production of IL-4 by mast cells in all the cases analyzed. There was an apparent difference in the number of mast cells in relation to the histological variants of the interface. The increase in the number of mast cells and IL-4 production was more pronounced in cases with heavy macrophage infiltrate than those exhibiting a predominance of giant cells. The findings imply that the recruitment of mast cell and IL-4 expression precede the granulomatous reaction and may have a role in the induction of a number of immunopathological changes related to mast cell activation by biomaterial particles.

Human monocyte/macrophage adhesion, macrophage motility, and IL-4-induced foreign body giant cell formation on silane-modified surfacesin vitro

A cytokine-based, in vitro model of foreign body giant cell (FBGC) formation was utilized to examine the effect of biomaterial surface chemistry on the adhesion, motility, and fusion of monocytes and macrophages. Human monocytes were cultured for 10 days on 14 different silane-modified glass surfaces, during which time the cells assumed the macrophage phenotype. The adhesion of monocytes and macrophages during the culture period decreased by an average of approximately 50%, with the majority of cell loss observed during days 1-3. Most important, the adhesion of monocytes and macrophages was surface independent except for two surfaces containing terminal methyl groups, which decreased adhesion levels. Interleukin-4 (IL-4) and granulocyte-macrophage colony-stimulating factor (GM-CSF) were added to the medium to induce FBGC formation and enhance macrophage adhesion, respectively. Surprisingly, GM-CSF decreased long-term monocyte/macrophage adhesion. IL-4-induced FBGC density was strongly influenced by the surface carbon content, as determined by X-ray photoelectron spectroscopy (XPS). In contrast, contact angle and surface energy displayed no correlation with FBGC formation. The motility of adherent macrophages, as measured by time-lapse confocal microscopy, was not affected significantly by differences in surface chemistry or the addition of cytokines. The surface dependence of FBGC formation is hypothesized to be the result of varying levels of silane-derived surface carbon.

Interleukin-13 induces human monocyte/macrophage fusion and macrophage mannose receptor expression.

Inasmuch as we recently demonstrated that IL-4 is a strong inducer of monocyte/macrophage fusion and IL-13 has been observed to mimic many of the biologic effects of IL-4, the ability of IL-13 to promote human macrophage fusion in vitro was tested and compared with IL-4-mediated fusion. IL-13 induced the fusion of monocyte-derived macrophages as potently as IL-4 under identical culture conditions, and resulted in foreign body-type giant cell formation. At optimal concentrations of cytokine added, statistically equal numbers of macrophages participated in IL-13- and IL-4-induced fusion (66.1 +/- 4.6% and 63.9 +/- 4.4%, respectively). However, the effects of IL-13 and IL-4 were not additive or synergistic, and the maximum fusion obtained when both IL-4 and IL-13 were added was 63.8 +/- 3.6%. Only anti-human IL-13 Abs inhibited IL-13-induced foreign body giant cell formation; the fusion-inducing effects of IL-13 continued to be observed in the presence of neutralizing Abs to IL-4 and several other anti-cytokine Abs, including Abs against IFN-gamma, granulocyte-macrophage CSF, IL-3, and TNF-alpha. IL-13 also significantly enhanced the fluorescence intensity detected by anti-human macrophage mannose receptor Abs, indicating that IL-13, like IL-4, up-regulates expression of the receptor that may be an essential participant in macrophage fusion. The results of this study demonstrate that IL-13, like IL-4, is a potent human macrophage fusion factor, and suggest that although IL-13 acts independently of IL-4 to promote foreign body giant cell formation, it may trigger a common mechanism for macrophage fusion.

Role for interleukin-4 in foreign-body giant cell formation on a poly(etherurethane urea) in vivo.

Interleukin-4 (IL-4) was previously shown to induce extensive macrophage fusion to form foreign-body giant cells (FBGCs) in vitro. In the present study, our goal was to extend these findings to an in vivo test environment on biomaterials. The subcutaneous cage-implant system was modified for mice to elucidate IL-4 participation in mediating FBGC formation in vivo. Exudate leukocyte concentrations from cages containing poly(etherurethane urea) (PEUU A') and empty cage controls indicated a similar inflammatory response that turned toward resolution by 14 days postimplantation, thus confirming the applicability of the cage-implant system in mice. FBGC kinetic analysis showed that the formation of mouse FBGCs occurs through the fusion of adherent macrophages at a constant rate up to 14 days of implantation. Purified goat anti-mouse IL-4 neutralizing antibody (IL4Ab) or normal goat nonspecific control IgG (gtIgG) at various concentrations, or recombinant murine IL-4 (muIL4) was injected into the implanted cages containing PEUU A' every 2 days for 7 days. The injection of IL4Ab significantly decreased the FBGC density on PEUU A' cage-implanted in mice, when compared with the nonspecific IgG or PBS injection controls. Conversely, the FBGC density was significantly increased by the injection of muIL4 when compared with nonspecific IgG and PBS injection controls. Adherent macrophage density, FBGC morphology, FBGC average size, and size distribution were not significantly different among IL4Ab, nonspecific control gtIgG, muIL4, and PBS control groups. Our data suggest that IL-4 participates in FBGC formation on biomaterials in vivo.

Theoretical analysis of in vivo macrophage adhesion and foreign body giant cell formation on strained poly(etherurethane urea) elastomers

Quantitative description of foreign body giant cell (FBGC) formation on poly(etherurethane urea) (PEUU) surfaces as a function of time can conceivably predict the effects of polymer characteristics on cellular responses in vivo. In the present study, the formation of FBGCs on strained and unstrained PEUUs was quantified with two parameters: the density of adherent macrophages present initially that participate in FBGC formation (d(o)) and the rate constant for cell fusion (k); both kinetic parameters were used to calculate the time-dependent FBGC density (dfc). Relationships were sought between results of the cellular analysis and the extent of environmental stress cracking (ESC), as characterized by scanning electron microscopy. Surface degradation was semiquantified with percent light transmittance. The materials used were: base PEUU, base PEUU with 1% Santowhite antioxidant powder, base PEUU with 5% Methacrol 2138F antifume agent, and base PEUU with both 1% Santowhite and 5% Methacrol 2138F. A comparison of unstrained base PEUU with base PEUU strained to 400% elongation indicated that the rate of cell fusion, but not d(o) and dfc, increased in the presence of strain. In all strained samples, additives that strongly affected the ESC also influenced FBGC kinetic parameters. Strained PEUU containing Santowhite had the lowest d(o), the slowest rate of cell fusion, and lowest dfc, and the least incidence of ESC. The results suggest that the incidence of ESC in PEUU was decreased in the presence of Santowhite, which also lowered the number of adherent macrophages participating in FBGC formation, the rate of FBGC formation and the subsequent FBGC density. These studies also indicate that strain in PEUUs does not directly modulate the adherent macrophage and FBGC density. Further studies are necessary to delineate the relationship between PEUU strain and adherent macrophage and FBGC activation, which leads to the exocytosis of degrading agents and the observed incidence of biodegradation.

Theoretical analysis of in vivo macrophage adhesion and foreign body gaint cell formation on polydimethylsiloxane, low density polyethylene, and polyetherurethanes

Quantitative description of foreign body giant cell (FBGC) formation on implanted polymer surfaces as a function of time can conceivably correlate cell adhesion with polymer properties and possibly predict the behavior of the polymer in vivo. In the present study, the formation of FBGCs on various biomedical polymers was quantified by two parameters: the density of adherent macrophages present initially that participate in FBGC formation (d0) and the rate constant for cell fusion (k); both kinetic parameters were used to calculate the time-dependent FBGC density (dfc). The materials used were: three Pellethane poly(etherurethanes) (PEUs) varying in weight percent of hard segment, one poly(etherurethane urea) (PEUU), and NHLBI-DTB primary reference materials: low density polyethylene (LDPE), silica-free polydimethylsiloxane (PDMS). The results indicated that up to 5 weeks of implantation, FBGCs were formed from the fusion of one population of adherent macrophages present by 3 days post-implantation. Furthermore, only a small fraction (< 8%) of this initial adherent macrophage population participated in FBGC formation. Based on the results of previous studies and the current study, it was concluded that increase in PEU hard segment weight percent, surface hardness and hydrophobicity increased total protein adsorption and effectively increased d0 and dfc. No further correlations between the material properties of all polymers and the cell kinetics can be made at this time. However, this study demonstrated that macrophage adhesion and FBGC formation can be quantified with the cell fusion model, and are modulated by various polymer properties.

Theoretical analysis on cell size distribution and kinetics of foreign-body giant cell formation in vivo on polyurethane elastomers.

The nature of in vivo leukocyte adhesion and foreign-body giant cell (FBGC) formation on polyurethanes was studied through theoretical and statistical analyses in terms of cell size distribution, density changes, and kinetics of FBGC formation. The results showed that the size distribution of FBGCs followed a "most probable" distribution. During FBGC formation, the densities of FBGCs changed with time. At an early stage, the number of FBGCs increased with time to a maximum at the expense of macrophages. As more FBGCs were formed and less macrophages were present, the fusion of FBGCs among themselves became significant. This, in turn, caused a gradual decrease of FBGC density with time. The rate of FBGC formation was characterized by a rate constant that represented certain characteristics of cell fusion and FBGC formation and the density of initial FBGC-forming macrophages that were a small fraction of leukocytes adhering to the surface. The direct correlations of surface cracking and pitting and adherent FBGCs demonstrated the influence of phagocytic actions of FBGCs on the biostability of implanted polyurethanes. While the cracking was thought to be caused by oxidative degradation facilitated by oxygen ion/radical release of FBGCs, the pitting appeared to result from the Methacrol 2138F aggregates diffusing out of the polymer in an acidic microenvironment under FBGCs, which in turn could be enhanced by the surface degradation and cell phagocytosis. The added Santowhite powder in polyurethane had a significant influence on FBGC formation: It reduced FBGC density and rate of FBGC formation by reducing leukocyte adhesion and the number of macrophages participating in FBGC formation.

Experimental Hydroxyapatite Cement Cranioplasty

Hydroxyapatite cement is a calcium phosphate-based material that when mixed with water forms a dense paste that sets within 15 minutes and isothermically converts in vivo to a microporous hydroxyapatite implant. This cement was used to reconstruct bilateral 2.5-cm-diameter full-thickness critical-sized parietal skull defects in six cats. One side was reconstructed with 100 percent hydroxyapatite cement, and the other with a mixture of 50 percent hydroxyapatite cement and 50 percent ground autogenous bone by weight. These animals were sacrificed at 6 and 12 months after implantation. Positive and negative controls also were prepared. The anatomic contour of the soft tissue overlying all hydroxyapatite cement implants was well maintained, there were no wound infections or structural failures, and the implants were well tolerated histologically. None of the negative (unreconstructed) control defects was completely filled with repair bone, and all positive (methyl methacrylate) controls demonstrated foreign-body giant-cell formation and fibrous encapsulation of the implants. Examination of decalcified and undecalcified sections revealed progressive but variable replacement of the cement by new bone and soft tissue without a change in the shape or volume of the hydroxyapatite cement-reconstructed areas. New bone comprised 77.3 and 64.7 percent of the tissue replacing the hydroxyapatite cement and hydroxyapatite cement-bone implants, respectively. Replacement of the hydroxyapatite cement implants by new bone is postulated to occur by a combination of osteoconduction and implant resorption. These results indicate that further experimental research leading to the possible application of hydroxyapatite cement for full-thickness calvarial defect reconstruction in humans is warranted.

Effect of some additives on the biostability of a poly(etherurethane) elastomer

Four materials based on a single poly-(etherurethane) (PEU) prepared from MDI and PTMEG but differing in additives were studied in the cage implant system. The two additives studied were Santowhite powder at the 1% level and Methacrol 2138F 5%. Methacrol 2138F appeared to be immiscible with the base PEU and was dispersed in discrete domains about 0.5-micron in size. The retrieved PEU specimens were also cleaned and examined in the optical and scanning electron microscopes, and the size and density of adherent foreign body giant cells (FBGCs) were measured at implantation times up to 10 weeks. Methacrol 2138F had no effect on the density, coverage or size distribution of adherent FBGCs, but leaching of Methacrol 2138F was considered to be responsible for extensive pitting of the PEU surface. On the other hand, Santowhite powder appeared to inhibit formation of FBGCs, and while surface cracking and flaking were observed as early as 3 weeks postimplantation on some PEUs, the Santowhite powder effectively inhibited surface cracking and flaking up to the longest implantation time studied.

A longitudinal comparative histometric study of the biocompatibility of three local hemostatic agents

The biocompatibility was studied of 3 hemostatic agents (Astroplast™), Hemastogen™ and bone wax) implanted into experimental bone cavities together with their clearance from the implantation sites. The 3 agents had an acceptable hemostatic effect during the surgical procedure. However, marked differences regarding tissue reactions in the experimental bone cavities, as well as at the internal bone surfaces, were found between them. Astroplast and Hemastogen appear to provoke more adverse tissue reactions, including foreign body giant cell formation, compared with bone wax. All 3 hemostatic implants showed markedly delayed bone healing. It was concluded that their biocompatibility was not ideal but acceptable in view of the clinical advantages.

Foreign body reaction against cellophane in the athymic nude mice.

There are no differences in the multinucleate cell formation in normal and athymic mice after the subcutaneous implantation of a cellophane strip. The number of Ia+ epitheloid cells and multinucleate foreign body giant cells was lower and the number of epitheloid cells sharing the marker of activated macrophages (M 57) was higher in athymic compared to normal mice. The epitheloid cells of athymic and euthymic animals exhibited no difference in the expression of Mac-2 molecule. The difference of the expression of surface markers between athymic and euthymic animals does not influence the foreign body giant cell formation.

Subcutaneous Fat Necrosis of the Newborn

Subcutaneous fat necrosis of the newborn (SFNN) usually occurs during the first few weeks of life.¹It is characterized by necrosis of the subcutaneous fat with needle-shaped crystal formations within the fat cells. This process initiates a localized inflammatory process with foreign body giant cell formation.²Subcutaneous fat necrosis of the newborn is represented clinically by multiple subcutaneous, indurated, erythematous plaques and nodules. The lesions are painless and are not warm to palpation.^1,3Common locations for these lesions include the buttocks, back, arms, thighs, and shoulders.⁴Although the etiology of this condition is unknown, many theories concerning its cause have been postulated. Associations of SFNN with cold exposure, obstetrical trauma, asphyxia, idiopathic hypercalcemia, hyperprostaglandinemia, and pancreatitis have all been suggested.^1,3-5The following case offers support for neonatal asphyxia and trauma as possible etiologic factors in SFNN. <h3>Report of a Case</h3> A 43-week gestational-aged black male

Reactions of the articular capsule to wear products of artificial joint prostheses.

Examination of a great number of tissue samples taken from the newly formed capsules surrounding artificial joints reveals small particles of prosthetic material. Abraded from the joint by wear and tear, these particles of plastic, metal, and acrylic cement initiate a foreign-body reaction and result in the formation of granulation tissue, including macrophages and foreign-body giant cells. Typical features of tissue reactions exist for each of the materials from which prostheses are made. The consequent formation of scar tissue produces a thickening of the capsule, which, in turn, may cause a reduction in the mobility of the joint. In small amounts, the foreign-body particles are eliminated via the perivascular lymph spaces. Where this transport system is insufficient to handle the volume, however, the foreign-body response may extend to the whole environment surrounding the joint. In such cases, there may be loosening of the cemented prosthetic parts because of deterioration of contiguous bone anchors by the tissue membrane lining the bone cement.

Temporal arteritis: A critical evaluation of this disorder and a report of three cases

A brief clinical and pathologic summary of the syndrome of temporal arteritis is made, with a report of three new cases, one of which was fatal and in which an autopsy was performed. This condition, first reported in 1932 by Horton, Magath and Brown, is characterized by severe headaches, pain in the temporal region and the presence of inflamed, thickened and tortuous temporal arteries. Constitutional symptoms of a generalized infection are also present. The characteristic pathologic lesion consists of proliferation of inflamed fibrous tissue of all layers of the affected vessel, together with focal necrosis and granulomatous lesions associated with foreign body giant cell formation in the media. Good therapeutic results are obtained by procaine injection, surgical excision of a portion of the diseased vessel and, in at least one instance, antihistaminic therapy. The disorder is usually self-limited and non-fatal. Although generally a localized vascular disease of the temporal arteries, other cranial arteries, as well as arteries in other parts of the body, may show the same type of lesion. We believe the term temporal arteritis should be restricted to instances in which the affected vessel has undergone the characteristic granulomatous change associated with foreign body giant cells. We also suggest changing the regional designation temporal arteritis to that of a pathologic entity, such as non-specific granulomatous arteritis or, more simply, granulomatous arteritis.