Foreign body reactions induced by macrophages often cause delay or failure of wound healing in the application of tissue engineering scaffolds. This study explores the application of nanosilver (NAg) to reduce foreign body reactions during scaffold transplantation. An NAg hybrid collagen-chitosan scaffold (NAg-CCS) was prepared using the freeze-drying method. The NAg-CCS was implanted on the back of rats to evaluate the effects on foreign body reactions. Skin tissue samples were collected for histological and immunological evaluation at variable intervals. Miniature pigs were used to assess the effects of NAg on skin wound healing. The wounds were photographed, and tissue samples were collected for molecular biological analysis at different time points post-transplantation. NAg-CCS has a porous structure and the results showed that it could release NAg constantly for two weeks. The NAg-CCS group rarely developed a foreign body reaction, while the blank-CCS group showed granulomas or necrosis in the subcutaneous grafting experiment. Both matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1) were reduced significantly in the NAg-CCS group. The NAg-CCS group had higher interleukin (IL)-10 and lower IL-6 than the blank CCS group. In the wound healing study, M1 macrophage activation and inflammatory-related proteins (inducible nitric oxide synthase (iNOS), IL-6, and interferon-‍γ (IFN-‍γ)) were inhibited by NAg. In contrast, M2 macrophage activation and proinflammatory proteins (arginase-1, major histocompatibility complex-II (MHC-II), and found in inflammatory zone-1 (FIZZ-1)) were promoted, and this was responsible for suppressing the foreign body responses and accelerating wound healing. In conclusion, dermal scaffolds containing NAg suppressed the foreign body reaction by regulating macrophages and the expression of inflammatory cytokines, thereby promoting wound healing.
Animals ; Rats ; Swine ; Interleukin-6 ; Macrophage Activation ; Tissue Inhibitor of Metalloproteinase-1 ; Wound Healing ; Foreign-Body Reaction ; Foreign Bodies ; Chitosan

BACKGROUND: The open reduction of craniofacial bone fractures requires internal fixation using metal plates and screws, which have been considered the gold standard. However, metal implants pose a risk of palpation, protrusion, and foreign body reaction, and they may require an additional operation for removal. Recently, good results have been reported for absorbable implants which complement the disadvantages of metal implants. This study presents the results of using absorbable mesh, plates, and screws with cyanoacrylate for more accurate and firmer fixation of comminuted fractures of the maxilla. METHODS: In total, 235 patients underwent operations for comminuted fractures of the maxilla. From January 2012 to December 2014, absorbable mesh and screws were used in 114 patients, while from January 2015 to December 2017, absorbable mesh, plates, and screws with cyanoacrylate were used in 121 patients. Open reduction of the bone fragments was performed, after which absorbable implants were accurately molded and fixed by screws. RESULTS: All patients underwent postoperative computed tomography scans, which showed highly accurate reduction and firm fixation in the patients who underwent procedures using absorbable implants, screws, and cyanoacrylate. There were no postoperative complications or cases of abnormal facial contour. CONCLUSION: When absorbable implants and screws are used for maxillary fractures, no additional surgery to remove the metal plate is required. In addition, the use of cyanoacrylate enables accurate and firm fixation of the tiny bone fragments that cannot be fixed with screws.
Absorbable Implants ; Complement System Proteins ; Cyanoacrylates ; Foreign-Body Reaction ; Fractures, Bone ; Fractures, Comminuted ; Fungi ; Humans ; Maxilla ; Maxillary Fractures ; Palpation ; Postoperative Complications

BACKGROUND: Topical hemostatic agents are used when ligation, electrocauterization, or other conventional hemostatic methods are impractical. Because a hemostatic agent is a foreign body, it can cause foreign body reactions, inflammation, and infections that can interfere with the wound healing process. Therefore, we should select hemostatic agents after considering their effects on wound healing. Here, we compared the effects of hemostatic agents on wound healing in a rectus abdominis muscle defect in rats. METHODS: Twelve Sprague Dawley rats were subjected to creation of a 6 × 6 mm defect in the rectus abdominis muscle and divided into four groups: control group; group A, Tachosil fibrin sealant patch; group B, Surgicel Fibrillar oxidized regenerated cellulose; and group C, Surgicel Snow oxidized regenerated cellulose. For the histologic analysis, biopsies were performed on the 3rd, 7th, and 27th days. RESULTS: The foreign body reaction was the weakest in group A and most significant in group C. The inflammatory cell infiltration was the weakest in group A and similar in groups B and C. Muscle regeneration differed among periods. The rats in group A were the most active initially, while those in group C showed prolonged activity. CONCLUSION: Tachosil and Surgicel administration increased inflammation via foreign body reactions, but the overall wound healing process was not significantly affected. The increased inflammation in the Surgicel groups was due to a low pH. We recommend using Tachosil, because it results in less intense foreign body reactions than Surgicel and faster wound healing due to the fibrin action.
Animals ; Biopsy ; Cellulose ; Cellulose, Oxidized ; Fibrin Tissue Adhesive ; Fibrin ; Fibrinogen ; Foreign Bodies ; Foreign-Body Reaction ; Hemostatics ; Hydrogen-Ion Concentration ; Inflammation ; Ligation ; Rats ; Rats, Sprague-Dawley ; Rectus Abdominis ; Regeneration ; Snow ; Thrombin ; Wound Healing ; Wounds and Injuries

PURPOSE: We investigated the biocompatibility of n-butyl-2-cyanoacrylate (NBCA) in the cervical deep tissues of rats to assess its biocompatibility. METHODS: A total of 30 Sprague-Dawley rats were injected with NBCA. After 30, 90, 180, and 360 days, cubes of tissue (1 cm × 1 cm × 1 cm) surrounding the NBCA and normal tissue from the other side of the neck were excised from each rat. The adhesion of NBCA to adjacent structures was examined histologically. Cells were counted per high-power field (HPF), and fibrosis was graded with the measurement of fibrotic thickening. RESULTS: All animals displayed normal behavior without any symptoms of distress throughout the study. There was no recognizable inflammatory reaction, foreign body reaction, or fibrosis in the 30 control samples. The analyses of experimental samples showed significantly decreased inflammatory cell counts over time (lymphoplasma cell count decreased from 100 (range, 70–100) to 30 (range, 30–50) per HPF, P = 0.010; neutrophil count decreased from 2 (range, 2–30) to 0 (range, 0–2) per HPF, P = 0.017). However, there was no significant difference in the number of multinuclear giant cells throughout the study period (a decrease from 22 [range, 16–34] to 16 [range, 12–22] per HPF, P = 0.287). The level of fibrosis was Common Toxicity Criteria ver. 4.0 Grade 1 without further thickening (P = 0.600). However, maturation of fibrosis progressed gradually. CONCLUSION: NBCA was biologically tolerable in the cervical deep tissues of rats. However, precautions are needed with respect to preventing a sustained foreign body reaction and fibrosis.
Animals ; Biocompatible Materials ; Cell Count ; Chyle ; Cyanoacrylates ; Enbucrilate ; Fibrosis ; Foreign-Body Reaction ; Giant Cells ; Neck ; Neck Dissection ; Neutrophils ; Prospective Studies ; Rats ; Rats, Sprague-Dawley

Maxillary implants are inserted in the upward direction, meaning that they oppose gravity, and achieving stable support is difficult if the alveolar bone facing the maxillary sinus is thin. Correspondingly, several sinus-lifting procedures conducted with or without bone graft materials have been used to place implants in the posterior area of the maxilla. Even with these procedures available, it has been reported that in about 5% of cases, complications occurred after implantation, including acute and chronic sinusitis, penetration of the sinus by the implant, implant dislocation, oroantral fistula formation, infection, bone graft dislocation, foreign-body reaction, Schneiderian membrane perforation, and ostium plugging by a dislodged bone graft. This review summarizes common maxillary sinus pathologies related to implants and suggests an appropriate management plan for patients requiring dental implantation.
Dental Implantation ; Dental Implants ; Dislocations ; Foreign-Body Reaction ; Gravitation ; Humans ; Maxilla ; Maxillary Sinus ; Maxillary Sinusitis ; Nasal Mucosa ; Oroantral Fistula ; Pathology ; Postoperative Complications ; Sinusitis ; Transplants

Pseudotumors are not uncommon complications after total hip arthroplasty (THA) and may occur due to differences in bearing surfaces of the head and the liner ranging from soft to hard articulation. The most common causes of pseudotumors are foreign-body reaction, hypersensitivity and wear debris. The spectrum of pseudotumor presentation following THA varies greatly-from completely asymptomatic to clear implant failure. We report a case of pseudo-tumor formation with acetabular cup aseptic loosening after revision ceramic-on-metal hip arthroplasty. The patient described herein underwent pseudotumor excision and re-revision complex arthroplasty using a trabecular metal shell and buttress with ceramic-on-polyethylene THA. Surgeons should be aware of the possibility of a pseudotumor when dealing with revisions to help prevent rapid progression of cup loosening and implant failure, and should intervene early to avoid complex arthroplasty procedures.
Acetabulum ; Arthroplasty ; Arthroplasty, Replacement, Hip ; Foreign-Body Reaction ; Head ; Hip ; Humans ; Hypersensitivity ; Surgeons

Among different graft materials for craniofacial reconstruction, calcium phosphate cements have the advantages of alloplastic grafts and wide use. The authors report a case of foreign body reaction following frontal reconstruction with JectOS (an injectable calcium orthophosphate cement; Kasios) and reviewed the literature on complications of this material after craniofacial reconstruction from 2002 to 2017. Complications were categorized into two groups: immunologic reactions (consisting of seroma collection, chronic sinus mucosa swelling, and foreign body reaction) and non-immune events (infection, fragmentation, and ejection). It is wise to use calcium phosphate-based material only in selected cases with small defects, and long-term follow-up is needed to observe their consequences.
Calcium* ; Follow-Up Studies ; Foreign Bodies ; Foreign-Body Reaction ; Mucous Membrane ; Phosphates ; Seroma ; Transplants

BACKGROUND: Since the survival of grafted fat requires successful revascularization, we hypothesized that local delivery of erythropoietin (EPO), a hemangiogenic and antiapoptotic factor, might enhance the survival of fat grafts in a nude mouse model. METHODS: Our experiment consisted of 2 parts. The first involved direct injection of EPO or saline at the grafting site before fat grafting and for 4 days afterwards. In the second part, EPO or saline was delivered continuously for 1 week via an osmotic pump device, and a group without an implantable pump represented the control group. After 16 weeks, the surviving fat grafts were weighed and subjected to histomorphometry. RESULTS: In the first experiment, fat graft survival was higher in the EPO-injected group, but not statistically significant (69.2% vs. 59.2%; P=0.21). Histomorphometry showed significantly higher levels of microvessel formation and less cystic degeneration in the EPO-injected group. In the second experiment, the survival rate was significantly lower in both pump groups than in the control group (40.7% in the EPO pump group, 7.7% in the saline pump group, and 66.7% in the control group). CONCLUSIONS: Local injection of EPO into the fat graft site appeared to improve graft survival, with increased angiogenesis, suppressed inflammation, and decreased degeneration. However, the insertion of an osmotic pump exerted detrimental effects on graft survival and the histomorphometric profiles of the fat graft compared with the control group due to the overwhelming foreign body reaction.
Adipose Tissue ; Animals ; Erythropoietin* ; Foreign Bodies* ; Foreign-Body Reaction* ; Graft Survival* ; Inflammation ; Injections, Subcutaneous* ; Mice ; Mice, Nude* ; Microvessels ; Survival Rate ; Transplants*

A rapid freezing/lyophilizing/reinforcing process is suggested to fabricate reinforced keratin/hydroxyapatite (HA) scaffold with improved mechanical property and biocompatibility for tissue engineering. The keratin, extracted from human hair, and HA mixture were rapidly frozen with liquid nitrogen and then lyophilized to prepare keratin/HA laminar scaffold. The scaffold was then immersed in PBS for reinforcement treatment, and followed by a second lyophilization to prepare the reinforced keratin/HA scaffold. The morphology, mechanical, chemical, crystal and thermal property of the keratin/HA scaffold were investigated by SEM, FTIR, XRD, DSC, respectively. The results showed that the keratin/HA scaffold had a high porosity of 76.17 ± 3%. The maximum compressive strength and compressive modulus of the reinforced scaffold is 0.778 and 3.3 MPa respectively. Subcutaneous implantation studies in mice showed that in vivo the scaffold was biocompatible since the foreign body reaction seen around the implanted scaffold samples was moderate and became minimal upon increasing implantation time. These results demonstrate that the keratin/HA reinforced scaffold prepared here is promising for biomedical utilization.
Animals ; Compressive Strength ; Durapatite ; Foreign-Body Reaction ; Freeze Drying ; Hair ; Humans ; Mice ; Nitrogen ; Porosity ; Spectroscopy, Fourier Transform Infrared ; Tissue Engineering

Postsurgical adhesion formation is a significant clinical problem within every surgical specialty. Currently, adhesion barriers are used in many surgical interventions and while they have become a subject of an increasing interest for their effectiveness, there has not been any reports on the adverse effects of these anti-adhesion agents. Three different types of antiadhesive agents (SurgiWrap®, Guardix-Sol®, Interceed®) have been noted as effective in adhesion prevention. We report, with a review of literature, on a patient who had a foreign body reaction that caused a side effect of anti-adhesion SurgiWrap® after thyroid surgery.
Foreign Bodies* ; Foreign-Body Reaction ; Humans ; Thyroid Gland