Foreign Body Giant Cells Research Articles

Novel large-pore lightweight polypropylene mesh has better biocompatibility for rat model of hernia.

Abdominal wall hernias are repaired with tension-free prosthetic materials but there remains a foreign body response (FBR) to commonly used polypropylene mesh. Thus, we should optimize mesh materials to improve the patient outcomes after surgery. A polypropylene mesh was developed with wrap knitting technique. The physical, mechanical and biocompatible characteristics were tested in a rat abdominal hernia model and compared to ULTRAPRO and Easy Prosthesis. Polypropylene mesh of two pore sizes was developed (LP-WKPM and SP-WKPM). Compared with ULTRAPRO and Easy Prosthesis mesh, the novel mesh were lighter, thinner, and stronger (p < 0.05). Among the four implanted mesh types, there were fewer inflammatory cells and foreign body giant cells surrounding LP-WKPM fibers (p < 0.05), and significantly fewer mononuclear cells and less neovascularization between LP-WKPM fibers (p < 0.05) On day 15, 30 and 90 after implantation there were no differences in foreign body giant cells compared to 15 days after implantation (p>0.05). We developed a novel large-pore lightweight polypropylene mesh that produced less FBR and better biocompatibility in an abdominal wall hernia model. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1269-1275, 2018.

Research progress in the function of monocyte/macrophage-lineage origin cells in the peri-implant osseointegration interface

Although many studies have focused on how material surface modifications can promote stem cell differentiation toward osteogenic osteoblasts, little is known about the reaction between material surface and other cells, including osteoclasts and foreign body giant cells. Dental implant osseointegration results from the functional coupling and equilibrium not only between osteoblasts and osteoclasts but also between bone tissue and immune system. Osteoclasts and foreign body giant cells share the same origin, monocyte/macrophage lineage cells, which have initially got concerns in the field of implant osseointegration with regard to their peri-implant distribution and biological functions. Up-to-date data has shown that cells of monocyte/macrophage lineage origin manifest key roles in the establishment of peri-implant osseointegration and the long-term maintenance of marginal bone level and the prevalence of peri-implantitis. However, preliminary progress has been made in the subtypes, phenotypes vs. genotypes, and functions of monocyte/macrophage-lineage-originated cells on the osseointegration interface, quite a lot of facts still remain unclear, especially the potential and the rapeutic targets which could coordinate the cellular peri-implant microenvironment and the implant osseointegrated interface in the short and long term. This review will focus on the current progress in the function of monocyte/macrophage-lineage origin cells on the peri-implant osseointegration interface.

Gossypiboma: A diagnosis not to forget

Granuloma formation is a specific type of chronic inflammation initiated by infectious and noninfectious agents with an aggregation of multinucleated giant cells. Foreign bodies can penetrate soft tissues in connection with accidents through open wounds and lacerations. Foreign body giant cells are most commonly observed at the tissue interface where the size of foreign particulate is too large to permit macrophage phagocytosis. A case of foreign body granuloma in the mandible is presented.

Lumbar Gout Tophus Mimicking Epidural Abscess with Magnetic Resonance Imaging, Bone, and Gallium Scans.

Gout is a common metabolic disorder, typically diagnosed in peripheral joints. Tophaceous deposits in lumbar spine are a very rare condition with very few cases reported in literature. The following is a case report of a 52-year-old patient with low back pain, left leg pain, and numbness. Serum uric acid level was in normal range. magnetic resonance imaging, bone scan, and gallium-67 images suggested an inflammatory-infectious process focus at L4. After a decompressive laminectomy at L4–L5 level, histological examination showed a chalky material with extensive deposition of amorphous gouty material surrounded by macrophages and foreign-body giant cells (tophaceous deposits).

Man with a swollen mass on sacrococcygeal region.

A 43-year-old male patient presented to the emergency department with 8 days of a painful swollen mass on sacrococcygeal region. He had no personal or family medical conditions and was receiving cephalexin 500 mg four times a day two days ago. Examination revealed an erythematous, fluctuant, swollen mass on sacrococcygeal region and an orifice at the buttock cleft (A). He was afebrile and nontoxic. Laboratory study results were unremarkable. Incision, drainage, currettage were made, leaving the surgical wound open for secondary healing. The diagnosis of pilonidal cyst with abscess was performed. Pilonidal sinus probably derives from the perineal pilosebaceous unit and precursor pits associated with trapped hairs. The penetrating hairs may cause a foreign-body giant cell reaction, sometimes with secondary bacterial infection, with can cause a sudden onset of pilonidal abscess. It occurs more commonly in individuals with stiff dark or auburn hair. There are four clinical presentation of the disease: symptomatic, acute pilonidal abscess, chronic fistulizing form or complex pilonidal sinus disease. Chronic fistulizant form is the most common clinical presentation. The sacrococcygeal location is the most common site but it can occur on the pubis, anterior perineum and very rarely, the penis. Asymptomatic pits do not require treatment. For acute abscesses, the options available are: aspiration followed by treatment with antibiotics and later curative intent surgery; drainage without curettage; drainage and curettage.

Tumor necrosis factor receptor-associated factor 6 is required to inhibit foreign body giant cell formation and activate osteoclasts under inflammatory and infectious conditions.

Osteoclasts and foreign body giant cells (FBGCs) are derived from common progenitors and share properties such as multi-nucleation capacity induced by cell-cell fusion; however, mechanisms underlying lineage determination between these cells remain unclear. Here we show that, under inflammatory conditions, osteoclasts are stimulated in a manner similar to M1 macrophages, while formation of FBGCs, which exhibit M2-like phenotypes, is inhibited in a manner similar to that seen in M1/M2 macrophage polarization. FBGC/osteoclast polarization was inhibited by conditional knockout of tumor necrosis factor receptor associated factor 6 (Traf6) in adults in vivo and in vitro. Traf6-null mice were previously reported to die soon after birth, but we found that Traf6 deletion in adults did not cause lethality but rather inhibited osteoclast activation and prevented FBGC inhibition under inflammatory conditions. Accordingly, basal osteoclastogenesis was significantly inhibited by Traf6 deletion in vivo and in vitro and accompanied by increased bone mass. Lipopolysaccharide-induced osteoclast formation and osteolysis were significantly inhibited in Traf6 conditional knockout mice. Our results suggest that Traf6 plays a crucial role in regulating M1 osteoclast and M2 FBGC polarization and is a potential therapeutic target in blocking FBGC inhibition, antagonizing osteolysis in inflammatory conditions, and increasing bone mass without adverse effects in adults.

Osteoclast-like giant cells in invasive breast cancer predominantly possess M2-macrophage phenotype

Breast carcinoma with osteoclast-like giant cells (OGCs) is a rare tumor; however, their clinicopathological aspects remain unclear. We described the clinicopathological characteristics of 8 patients with breast carcinoma with OGCs. Immuno-phenotypes of the OGCs were comparatively examined with that of foreign body giant cells (FBGCs) in 4 cases of granulomatous reaction (GR) without cancerous elements. In most cancers, tumors displayed cribriform and tubular growth patterns. Three cases showed moderate to high nuclear grade, while all the other tumors had low nuclear grade. Six patients were estrogen receptor (ER) positive, while triple negative phenotype was identified in 2 patients. During the follow-up period, 1 patient had local recurrence of the tumor, and all the patients remained alive. All OGCs and FBGCs expressed CD68, a pan-macrophage marker. OGCs in all the breast cancers showed moderate to high expression of CD163 — a marker of M2-macrophage with pro-tumoral function — whereas its expression in FBGCs was low to moderate (p=0.04). CD86 — a marker of M1-macrophage with a tumoricidal activity — was positive in the OGCs of 3 breast cancers, and in the FBGCs of 3 GR cases (p=0.15). The expression of CD163 was significantly higher than that of CD86 in the OGCs of breast cancer (p<0.001), whereas they were comparable in the FBGCs of GR (p=0.79). In summary, we found that breast carcinoma with OGCs mostly exhibited cribriform and tubular growth pattern, ER positivity, and predominantly possessed the M2-macrophage phenotype. However, the clinical significance of OGCs in breast cancer needs to be elucidated in further studies involving a larger number of cases.

Fate of Worn-Out Functional Teeth in the Upper Jaw Dentition of Sicyopterus japonicus (Gobioidei: Sicydiinae) During Tooth Replacement.

Mochizuki and Fukui (Jpn J Ichthyol 30 () 27-36) studied the development and replacement of the upper jaw teeth in a Japanese fish species, Sicyopterus japonicus (Gobioidei: Sicydiinae), and they reported that worn-out functional teeth in the upper jaw were not shed outside the skin but were taken into the soft tissue of the upper jaw and completely resorbed there. To date, however, this phenomenon appears poorly documented. Furthermore, the mechanism for the resorption of these teeth remains to be determined. In this study, we examined this phenomenon by using 3D microcomputed tomography (m-CT), scanning electron microscopy (SEM), and various techniques of light (LM) and electron (EM) microcopy. This study demonstrated that the upper jaw dentition of this fish was more or less simultaneously replaced with the replacement occurring during short time periods and that the lingual movement of the replacement teeth to the functional tooth position advanced simultaneously in a given row. Furthermore, our study also revealed that many worn-out functional teeth were engulfed by the oral epithelium, invaginated into the lingual shallow ditch of the premaxilla, and were resorbed/degraded completely by numerous foreign body giant cells rather than by odontoclasts during periods of at least three intervals of tooth replacement. The complete resorption/degradation of worn-out functional teeth in the soft tissue of the upper jaw suggests the possibility of the reuse of their components (minerals such as Ca and P, including Fe) for rapid and successional production of new replacement teeth in the upper jaw of adult S. japonicus. Anat Rec, 2017. © 2017 Wiley Periodicals, Inc. Anat Rec, 301:111-124, 2018. © 2017 Wiley Periodicals, Inc.

Effects of the fibrous topography-mediated macrophage phenotype transition on the recruitment of mesenchymal stem cells: An in vivo study

Host responses to a biomaterial critically influence its in vivo performance. Biomaterial architectures that can recruit endogenous host stem cells could be beneficial in tissue regeneration or integration. Here, we report that the fibrous topography of biomaterials promotes the recruitment of host mesenchymal stem cells (MSCs) by facilitating the macrophage phenotype transition from M1-to-M2. Electrospun poly (ε-caprolactone) fiber (PCL-fiber) films were implanted into the subcutaneous tissues of rats, and the response of host cells to the PCL-fiber was evaluated and compared with those of solid ones (PCL-solid). During the initial post-implantation period, greater numbers of cells were recruited and adhered to the PCL-fiber compared to the PCL-solid, and the cells exhibited the M1 phenotype, which was supported by the enhanced adsorption of complement C3a to the implanted PCL-fiber. Subsequently, the PCL-fiber supported the macrophage phenotype transition from M1-to-M2, which was confirmed by the ratio of M2/M1 marker (CD163/CCR7)-positive cells and by the expression of M2/M1 markers (arginase-1/iNOS). The PCL-fiber also reduced the formation of foreign body giant cells. MSC marker (CD29, CD44, and CD90)-positive cells began to appear as early as day 4 on the PCL-fiber, while few MSCs were observed on the PCL-solid. The MSCs migration ex vivo assay showed that MSCs substantially migrated across the trans-wells toward the implanted PCL-fiber. The cells on the implanted PCL-fiber expressed and secreted substantial levels of SDF-1 (CXCL-12), while anti-SDF-1 neutralizing antibody abrogated the MSCs migration. Taken together, these results provide evidence that the fibrous topography of biomaterials enhances the recruitment of MSCs by promoting macrophage recruitment, facilitating M1-to-M2 transition, and enhancing SDF-1 secretion.

Severe Bilateral Pulmonary Fibrosis in a Young Syrian Refugee

SESSION TITLE: Critical Care 3 SESSION TYPE: Affiliate Case Report Slide PRESENTED ON: Sunday, October 29, 2017 at 04:30 PM - 05:30 PM INTRODUCTION: A civil war in Syria has generated a humanitarian crisis affecting the health care of its citizens and refugees. Environmental lung diseases in areas of conflict may pose significant health implications. Numerous challenges in providing health care to these individuals exist including lack of medical records, inability to confirm toxic exposures, and distrust in foreign medical teams. We discuss the case of a young Syrian refugee who presented with severe bilateral fibrotic lung disease complicated by bilateral pneumothoraces. CASE PRESENTATION: A 35 year old male Syrian refugee developed worsening dyspnea since his arrival to the United States a few days prior to his presentation. He was cachectic and had decreased bilateral breath sounds. Chest computed tomography revealed bilateral coarse reticular opacities, innumerable peri-lymphatic and centrilobular nodules, confluent fibrotic-type consolidative opacities in all lung lobes, and bilateral pneumothoraces. He developed acute hypoxic respiratory failure requiring mechanical ventilation. Bilateral chest tubes were placed. He underwent bronchoscopy with bronchial alveolar lavage and transbronchial biopsies demonstrating non-specific focal fibrosis, foreign body type giant cell reaction, and focal airspace hemorrhage. A tracheostomy was placed. It was evident he was initially concerned about disclosing historical details due to uncertainty of implications. He reported a brief history of working with glass, but biopsy findings were not consistent with silicosis. Investigation for infectious etiologies was negative. His immigration documents also noted negative tests for tuberculosis. Overall, his evaluation suggested a non-specific environmental lung disease. He acknowledged exposure to dust, fumes, gases and smoke at conflict zones but was unable to identify them. The severity of his lung disease precluded surgical biopsy. His treatment was determined to be mostly supportive with the goal of rehabilitation and consideration of future lung transplantation. DISCUSSION: This case is an example of accelerated non-specific fibrotic lung disease in a young refugee from war-torn Syria. In the absence of alternative diagnosis, it is imperative to consider this patient's exposure to war conditions as a potential risk factor for development of environmental lung disease. Careful examination of all information available including immigration documents and building a trustful patient-doctor relationship are essential in the care of such patients. CONCLUSIONS: More than 4.5 million people have fled Syria since the beginning of a major political conflict in 2011 [1]. The medical community should remain alert to the potential health implications of environmental lung diseases in war zone areas. The number of refugees exposed to toxic substances is unknown, and this population may be at significant risk for development of lung disease. Reference #1: Syria Emergency. The UN Refugee Agency. UNHCR.org. Accessed Mar 6, 2017. DISCLOSURE: The following authors have nothing to disclose: Susan Vehar, Humberto Choi No Product/Research Disclosure Information

Pathological findings in explanted vaginal mesh

In light of the legal issues and the shortage of data on histopathological findings, we summarized our experience on how explanted vaginal mesh specimens were managed in a surgical pathology practice during the last 5 years. Clinical history and pathology reports were collected from 155 women undergoing transvaginal tape excision. The degree of chronic inflammation, fibrosis, foreign-body giant cell reactions, the number of capillary vessels and nerve fibers, and the presence or absence of adipose tissue were recorded. Among the 155 patients, 65 (41.9%) were active medicolegal cases, with a significant increase in recent years. The main medical indications for mesh excision were pelvic pain, mesh erosion, voiding dysfunction, genital organ prolapse, and vaginal bleeding. In most cases, mild to moderate chronic inflammation with a mild degree of foreign-body giant cell reaction and minimal to mild fibrosis were found in explanted mesh specimens. The specimens were well vascularized without any evidence of nerve abnormality. Patient age correlated negatively with vaginal pain (P = .007) but positively with erosion (P = .005). In addition, the presence of adipose tissue within the explanted mesh correlated significantly with pelvic pain (P = .016). Overall, there was good tissue integration in all specimens. Considering the significant increase in the number of lawsuits in recent years, we recommend that all explanted vaginal mesh specimens be examined microscopically as well as grossly. A list of microscopic findings, including the presence or absence of adipose tissue, is suggested.

Calcifying epithelioma on the face of a middle-aged man.

A 42-year-old man presented with a nodule on the left cheek that had gradually increased in size. Physical examination revealed a yellowish subcutaneous tumor. The biopsy specimen revealed epithelial sheets consisting of anucleate squamous cells, basophilic cells, and foreign body giant cells. These findings confirmed that this tumor was a calcifying epithelioma.

Long-term complications evidenced studying the explanted Gore® HELEX® atrial septal defect occluder seven years after implantation: a case report

We present the results of the first morphological study of a Gore® HELEX® Septal Occluder 30 mm that was explanted seven years after interventional implantation due to a significant left-to-right shunt (7 mm) which resulted from the stretching of the concomitant patent foramen ovale by the occluder after atrial septal defect closure. Complete endothelialization of the surface of the device, the formation of the connective tissue around the implant, minor chronic inflammation, the appearance of foreign body giant cells and weakened myocardial cells adjacent to the implant as well as enhanced expression of matrix metalloproteinases were demonstrated.

ID: 1022 Acellular muscle scaffolds: Histological and biochemical evaluation

Anterior tibial muscle of C57Bl6/J mice was subjected to decellularization with hypotonic solution, detergents and DNase. Resulting acellular scaffolds were examined to characterize the content of chromatin, cell cytoplasm and extracellular matrix components incl. basal laminas, fibres and glycoproteins. Although the sarcoplasm and cell nuclei were removed, the general skeletal muscle microarchitecture with ECM of stromal components remained well preserved at light and electron microscopic levels. Moreover, basal laminas contouring honeycomb-like structures left after removal of myofibres and vascular endothelium remained intact. Immunostaining of scaffolds for collagen IV and laminin confirmed positivity of basal laminas. Histochemical staining of deparaffinised scaffold sections identified well organized fibres after staining with green trichrome, Sirius red, Weigert’s resorcin fuchsin and Gomori impregnation. Chemical analysis gave evidence of reduced dsDNA and well-preserved collagen according to high hydroxyproline content and laminin as documented by Western blotting. We cultured scaffolds seeded with murine myogenic cells in vitro and confirmed their cytocompatibility as the cells were able to adhere, grow and migrate through the ECM without affecting the scaffold structure. Myogenic cells were able to migrate in the endomysium and start to fuse. Implantation of decellularized scaffolds into an artificial cavity inside of anterior tibial muscle of mice in vivo confirmed the scaffolds were colonized soon by recipient inflammatory cells without formation of foreign body giant cells. Scaffolds were well integrated with recipient skeletal muscle and gradually resorbed within 3 weeks. Our results confirm decellularized muscle scaffold is a promising alternative for rebuilding the skeletal muscle organ as it can preserve basic chemical components and the tissue microstructure and show biocompatibility for myogenic cells as demonstrated in vitro and in vivo.

Histological Analysis of Early Osteolysis in Total Ankle Arthroplasty

Category: Ankle Arthritis Introduction/Purpose: The purpose of this study was to perform a histological comparative analysis of tibiotalar joint samples taken from areas of osteolysis adjacent to total ankle arthroplasties vs control synovial specimens to determine the reaction to and presence of polyethylene (PE) particles. Methods: A total of 57 pathology samples were identified in the osteolysis group, while 11 were identified in the control group. For each sample, hematoxylin and eosin, Oil Red O (ORO), and macrophage marker CD163-stained slides were created. Polarized light and ORO stain were used to identify PE particles. The presence of metal particles and giant cell reaction to PE particles were also scored. Results: Macrophages, PE particles, metallosis, and foreign body giant cell reaction scores were significantly higher in the osteolysis group compared with the control group. In the osteolysis group, ORO staining was positive in 93% (53/57), birefringent material was present in 96.5% (55/57), and macrophage infiltrates were present in 96.5% (55/57). Foreign body giant cell reaction with giant cells surrounding PE particles was present in 49.1% (28/57) of osteolytic specimens. The presence of foreign body giant cell reaction was associated with significantly higher macrophage, ORO, and polarizable material scores. The average time to surgery for osteolysis from the index ankle replacement was 6.0 (range, 0-15) years for the 57 patients in the osteolysis group. Conclusion: This study is the largest ankle arthroplasty histological analysis to show that areas of osteolysis consist of abundant polyethylene wear particles, present both intracellularly and extracellularly. Furthermore, these areas were associated with a CD163+ macrophage infiltrate and frequently a foreign body reaction with giant cells engulfing PE particles. It is likely that implant wear particles play a significant role in osteolysis based on the histopathology.

Adhesions, infl ammatory response and foreign body giant cells infi ltration of the topical hemostats TachoSil®, Hemopatch™ and Veriset™ – An Animal Study

Background: When liver bleeding cannot be controlled by conventional methods, a topical hemostatic patch can be applied during surgery. In recent years new hemostats have become available. The aim of this study was to investigate the degree of adhesion and infl ammation for three topical hemostatic patches, TachoSil®, Hemopatch™ and Veriset™.

Gouty tophi without hyperuricemia, an interesting case diagnosed by fine-needle aspiration cytology

Gout is a disorder of uric acid metabolism characterized by deposition of monosodium urate crystals in joint spaces or soft tissues. Gouty tophi can be the presenting feature of gout and can occur despite normal serum uric acid levels. Periarticular nodules can be a diagnostic dilemma for both clinicians and radiologists. A 39-year-old man presented with a nontender, firm swelling in right medial malleolus. His serum uric acid level was normal. Computed tomography scan report gave a differential diagnosis of synovial sarcoma and pigmented villonodular synovitis. Fine-needle aspiration cytology from the swelling revealed abundant granular amorphous deposits with needle-shaped crystals in a background of chronic inflammatory infiltrate. Biopsy from the swelling demonstrated the presence of needle-shaped crystals in a radial arrangement along with foreign-body giant cells and histiocytes. On the basis of cytological and histopathological findings, a diagnosis of gouty tophi was rendered.

Development of a New Outcome Prediction Model in Early-stage Squamous Cell Carcinoma of the Oral Cavity Based on Histopathologic Parameters With Multivariate Analysis: The Aditi-Nuzhat Lymph-node Prediction Score (ANLPS) System.

The aim of this study was to evaluate the histopathologic parameters that predict lymph node metastasis in patients with oral squamous cell carcinoma (OSCC) and to design a new assessment score on the basis of these parameters that could ultimately allow for changes in treatment decisions or aid clinicians in deciding whether there is a need for close follow-up or to perform early lymph node dissection. Histopathologic parameters of 336 cases of OSCC with stage cT1/T2 N0M0 disease were analyzed. The location of the tumor and the type of surgery used for the management of the tumor were recorded for all patients. The parameters, including T stage, grading of tumor, tumor budding, tumor thickness, depth of invasion, shape of tumor nest, lymphoid response at tumor-host interface and pattern of invasion, eosinophilic reaction, foreign-body giant cell reaction, lymphovascular invasion, and perineural invasion, were examined. Ninety-two patients had metastasis in lymph nodes. On univariate and multivariate analysis, independent variables for predicting lymph node metastasis in descending order were depth of invasion (P=0.003), pattern of invasion (P=0.007), perineural invasion (P=0.014), grade (P=0.028), lymphovascular invasion (P=0.038), lymphoid response (P=0.037), and tumor budding (P=0.039). We designed a scoring system on the basis of these statistical results and tested it. Cases with scores ranging from 7 to 11, 12 to 16, and ≥17 points showed LN metastasis in 6.4%, 22.8%, and 77.1% of cases, respectively. The difference between these 3 groups in relation to nodal metastasis was very significant (P<0.0001). A patient at low risk for lymph node metastasis (score, 7 to 11) had a 5-year survival of 93%, moderate-risk patients (score, 12 to 16) had a 5-year survival of 67%, and high-risk patients (score, 17 to 21) had a 5-year survival of 39%. The risk of lymph node metastasis in OSCC is influenced by many histologic parameters that are not routinely analyzed in pathologic reports. These significant independent factors were graded to design a scoring system that permits accurate evaluation of the risk of metastasis with accuracy independent of the traditional TNM system or isolated histologic parameters. The need for neck node dissection can be predicted depending upon the scores obtained.

Physiologic musculofascial compliance following reinforcement with electrospun polycaprolactone-ureidopyrimidinone mesh in a rat model

PurposeElectrospun meshes may be considered as substitutes to textile polypropylene implants. We compared the host response and biomechanical properties of the rat abdominal wall following reinforcement with either polycaprolactone (PCL) modified with ureidopyrimidinone-motifs (UPy) or polypropylene mesh. MethodsFirst we measured the response to cyclic uniaxial load within the physiological range both dry (room temperature) and wet (body temperature). 36 rats underwent primary repair of a full-thickness abdominal wall defect with a polypropylene suture (native tissue repair), or reinforced with either UPy-PCL or ultra-light weight polypropylene mesh (n = 12/group). Sacrifice was at 7 and 42 days. Outcomes were compliance of explants, mesh dimensions, graft related complications and semi-quantitative assessment of inflammatory cell (sub) types, neovascularization and remodeling. ResultsDry UPy-PCL implants are less stiff than polypropylene, both are more compliant in wet conditions. Polypropylene loses stiffness on cyclic loading. Both implant types were well incorporated without clinically obvious degradation or herniation. Exposure rates were similar (n = 2/12) as well as mesh contraction. There was no reinforcement at low loads, while, at higher tension, polypropylene explants were much stiffer than UPy-PCL. The latter was initially weaker yet by 42 days it had a compliance similar to native abdominal wall. There were eventually more foreign body giant cells around UPy-PCL fibers yet the amount of M1 subtype macrophages was higher than in polypropylene explants. There were less neovascularization and collagen deposition. ConclusionAbdominal wall reconstruction with electrospun UPy-PCL mesh does not compromise physiologic tissue biomechanical properties, yet provokes a vivid inflammatory reaction.

Polytetrafluoroethylene topographies determine the adhesion, activation, and foreign body giant cell formation of macrophages.

Polytetrafluoroethylene (PTFE) is one of the commonly used materials in making various cardiovascular implants. However, the success rates of these implants in several occasions are hindered by unwanted immune responses from immune cells, such as macrophages. In this study, we investigated the response of macrophages with different structures (flat, expanded, and electrospun) of PTFE having varied surface topographies: smooth planar surface (flat PTFE), node-fibrils (ePTFE), and randomly oriented microfibers (electrospun PTFE). The electrospun PTFE showed the least adhesion of macrophages. Also, the morphology of macrophages adhered on electrospun PTFE exhibited minimal activation. The macrophage pro-inflammatory cytokine secretions showed that the lowest level of TNF-α was produced on electrospun PTFE whereas IP-10 was produced in lowest levels on expanded PTFE (ePTFE). The production of IL-6 and MCP-1 cytokines was also dependent on the structure of PTFE that the macrophages interacted with, but in a time-dependent manner. Confocal microscopy images taken at 7, 14, and 21 days showed that the electrospun PTFE resulted in the lowest percentage of macrophage fusion, thus indicating the least possible chance of foreign body giant cell (FBGC) formation. Therefore, this study showed that electrospun PTFE with randomly oriented microfibers can provide reduced adhesion, activation, and FBGC formation of macrophages compared to the smooth and planar surface of flat PTFE and node-fibril structured surface of ePTFE. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2441-2450, 2017.