As the number of patients suffering from cardiovascular diseases and peripheral vascular diseases rises, the constraints of autologous transplantation remain unavoidable. As a result, artificial vascular grafts must be developed. Adhesion of proteins, platelets and bacteria on implants can result in stenosis, thrombus formation, and postoperative infection, which can be fatal for an implantation. Polyurethane, as a commonly used biomaterial, has been modified in various ways to deal with the adhesions of proteins, platelets, and bacteria and to stimulate endothelium adhesion. In this review, we briefly summarize the mechanisms behind adhesions, overview the current strategies of surface modifications of polyurethane biomaterials used in vascular grafts, and highlight the challenges that need to be addressed in future studies, aiming to gain a more profound understanding of how to develop artificial polyurethane vascular grafts with an enhanced implantation success rate and reduced side effect.
Humans ; Polyurethanes ; Biocompatible Materials ; Blood Vessel Prosthesis/adverse effects* ; Cardiovascular Diseases

OBJECTIVE: Graft rejection, with the possibility of a violent immune response, may be severe and life threatening. Our aim was to thoroughly investigate the biocompatibility and immunotoxicology of collagen-based dermal matrix (DM) before assessment in clinical trials. METHODS: DM was subcutaneously implanted in BALB/c mice in two doses to induce a potential immune response. The spleen and lymph nodes were assessed for shape, cell number, cell phenotype via flow cytometry, cell activation via CCK8 kit, Annexin V kit, and Ki67 immunostaining. Serum samples were used to measure antibody concentration by enzyme-linked immunosorbent assay. Local inflammation was analyzed by histology and immunohistochemistry staining. Data analysis was performed by one-way ANOVA and non-parametric tests. RESULTS: Our data illustrate that the spleen and lymph node sizes were similar between the negative control mice and mice implanted with DM. However, in the high-dose DM (DM-H) group, the total cell populations in the spleen and lymph nodes, T cells and B cells in the spleen had slight increases in prophase, and the low-dose DM (DM-L) group did not display gross abnormities. Moreover, DM-H initiated moderate cell activation and proliferation in the early phase post-immunization, whereas DM-L did not. Neither DM-H nor DM-L implantation noticeably increased IgM and IgG serum concentrations. Examination of the local cellular response revealed only benign cell infiltration and TNF-α expression in slides of DM in the early phase. CONCLUSION Overall, DM-H may have induced a benign temporary acute immune response post-implantation, whereas DM-L had quite low immunogenicity. Thus, this DM can be regarded as a safe product.
Animals ; Biocompatible Materials ; adverse effects ; analysis ; Collagen ; adverse effects ; immunology ; Dermis ; immunology ; surgery ; Female ; Flow Cytometry ; Immunity, Cellular ; Lymph Nodes ; immunology ; Mice ; Mice, Inbred BALB C ; Prostheses and Implants ; adverse effects ; Spleen ; immunology

Postoperative epidural adhesion is one of the most common causes of failed back surgery syndrome (FBSS), which can lead to back and leg pain or neurological deficit. Prevention of epidural adhesion after laminectomy is critical for improving the outcomes of lumbar surgery. The main origins of epidural fibrosis are raw surface of erector muscles and rupture fibers of intervertebral disc. The main current preventive methods for epidural adhesion include the usage of implants, chemicals and low dose radiation. However, most of them are still in experiment period. There are still controversies on the clinic usage of autograft free fat, ADCON-L, and Mitomycin C (MMC). The optimal implants are characteristics of better biocompatibility, degradable absorption and capability of existing for a certain period in body. The optimal medicine should have good effect on anti-desmoplasia, less side effects and long half-life. Besides, the combination of biodegradable medical film and drug and the mixture of two or more medical films are also the research frontlines of epidural adhesion. Further researches are required to explore new materials and drugs with stable and most favorable effect in preventing epidural adhesion.
Biocompatible Materials ; administration & dosage ; Epidural Space ; pathology ; Humans ; Laminectomy ; adverse effects ; Lumbar Vertebrae ; surgery ; Tissue Adhesions ; prevention & control

BACKGROUND: Wear cannot be completely prevented after total hip arthroplasty. If severe polyethylene (PE) liner wear develops, the so-called catastrophic failure occurs and metallosis develops. We postulated that longevity of the new implant may be affected after revision surgery for metallosis following a catastrophic failure of a PE liner due to the substantial amount of PE wear particles and infiltration of the metal particles in this catastrophic condition. METHODS: Twenty-three hips of 23 patients were identified because they showed metallosis during revision total hip arthroplasties performed in Seoul National University Hospital between January 1996 and August 2004. They were followed for at least 6.5 years after the index revision total hip arthroplasty. The clinical and radiological results of revision total hip arthroplasties in these patients were evaluated. RESULTS: The median Harris hip score increased from 60 points before revision total hip arthroplasties to 90 points at the final follow-up. Osteolysis was detected at an average of 9.3 years after revision total hip arthroplasties in 13 hips and acetabular cup loosening at average 9.8 years after revision total hip arthroplasties in 9 hips. With radiographic evidence of osteolysis and loosening as the end points, the 15-year survival rates were 28.2% and 56.0%, respectively. CONCLUSIONS: The survival rate of revision total hip arthroplasty in patients with metallosis following a catastrophic failure of a PE liner was low.
Adolescent ; Adult ; *Arthroplasty, Replacement, Hip ; Biocompatible Materials ; Female ; Hip Joint/radiography/surgery ; Hip Prosthesis/*adverse effects ; Humans ; Joint Diseases/radiography/*surgery ; Male ; Metals/adverse effects ; Metals, Heavy/*poisoning ; Middle Aged ; Osteolysis/etiology/surgery ; Poisoning/etiology/*surgery ; Polyethylene/adverse effects ; Prosthesis Design ; *Prosthesis Failure/etiology ; Reoperation ; Young Adult

Cell therapy has achieved tremendous success in regenerative medicine in the past several decades. However, challenges such as cell loss, death and immune-rejection after transplantation still persist. Biomaterials have been designed as carriers to deliver cells to desirable region for local tissue regeneration; as barriers to protect transplanted cells from host immune attack; or as reactors to stimulate host cell recruitment, homing and differentiation. With the assistance of biomaterials, improvement in treatment efficiency has been demonstrated in numerous animal models of degenerative diseases compared with routine free cell-based therapy. Emerging clinical applications of biomaterial assisted cell therapies further highlight their great promise in regenerative therapy and even cure for complex diseases, which have been failed to realize by conventional therapeutic approaches.
Animals ; Biocompatible Materials ; chemistry ; pharmacology ; Bioreactors ; Cell- and Tissue-Based Therapy ; adverse effects ; methods ; Drug Carriers ; chemistry ; pharmacology ; Humans ; Regenerative Medicine ; methods

This paper has briefly introduced the definition, classification, harms, sources and control of particles, lists the particle evaluation method of coronary stents. And the development trend of particle evaluation method of coronary stents is also analyzed.
Biocompatible Materials ; adverse effects ; Blood Vessel Prosthesis ; Coronary Artery Disease ; therapy ; Humans ; Particle Size ; Stents

PURPOSE: Augmentation rhinoplasty using alloplastic materials is a relatively common procedure among Asians. Silicon, expanded polytetrafluoroethylene (Gore-tex(R)), and porous high density polyethylene (Medpor(R)) are most frequently used materials. This study was conducted to analyze revisional rhinoplasty cases with alloplastic materials, and to investigate the usage of alloplastic materials and their complications. We also reviewed complications caused by various materials used in plastic surgery while operating rhinoplasty. MATERIALS AND METHODS: We report 581 cases of complications rhinoplasty with alloplastic implants and review of the literature available to offer plastic surgeons an overview on alloplastic implant-related complications. RESULTS: Among a total 581 revisional rhinoplasty cases reviewed, the alloplastic materials used were silicone implants in 376, Gore-tex(R) in 183, and Medpor(R) in 22 cases. Revision cases and complications differed according to each alloplastic implant. CONCLUSION: Optimal alloplastic implants should be used in nasal structure by taking into account the properties of the materials for the goal of minimizing their complications and revision rates. A thorough understanding of the mechanism involved in alloplastic material interaction and wound healing is the top priority in successfully overcoming alloplastic-related complications.
Asian Continental Ancestry Group ; *Biocompatible Materials/adverse effects ; Humans ; Polyethylene ; Polyethylenes ; *Polytetrafluoroethylene ; Postoperative Complications ; Prosthesis Implantation/*methods ; Rhinoplasty/*methods ; Silicones ; Treatment Outcome

Recently, injectable dermal fillers have become important alternatives to surgical procedures for the correction of facial wrinkles. Bovine collagen is the first approved material for filler injection, and several studies have shown its efficacy. However, the risk of developing an allergic reaction and xenogenic transmission of bovine spongiform encephalopathy remain among its disadvantages. In this randomized, double-blinded, split-face study, we compared the efficacy and safety of a porcine collagen filler (TheraFill(R)) with that of a bovine collagen filler (KOKEN(R)) for nasolabial fold correction. A total of sixty one patients with mild to severe nasolabial fold were randomized to receive TheraFill(R) and KOKEN(R) on contralateral sides of the face. During the 12-month follow-up period, improvement in the Wrinkle-Severity Rating Scale score was slightly higher in TheraFill(R) group than KOKEN(R) group, although the difference was not statistically significant. No serious adverse reactions were observed and both materials were tolerable in most cases. In conclusion, the long-term effect of TheraFill(R) on nasolabial fold correction was comparable to that of KOKEN(R), and it may be a good alternative to bovine collagen filler.
Adult ; Aged ; Animals ; Biocompatible Materials/therapeutic use ; Cattle ; Collagen/adverse effects/*therapeutic use ; Dermatologic Surgical Procedures/*methods ; Double-Blind Method ; Face/surgery ; Female ; Follow-Up Studies ; Humans ; Injections, Intradermal ; Male ; Middle Aged ; Nasolabial Fold/*surgery ; Prospective Studies ; Skin Aging ; Surgery, Plastic/*methods ; Swine ; Treatment Outcome

BACKGROUNDPretreatment with chemical agents could alter the surface chemistry of the silicone gel, which makes it suitable for epithelial migration onto its surface and thus enhances the cytobiocompatibility. This study aimed to evaluate the biological response of the corneal stroma to porous silicone gel pretreated with different chemical agents in vivo.

METHODSThe porous silicone gels were treated with a mixed acid solution containing 23.2% H2SO4 and 0.8% K2Cr2O7 for 10 or 15 minutes or with 30% H2O2 for 15 minutes. Discs (4 mm in diameter) were inserted into interlamellar stromal pockets of New Zealand white rabbits and followed up for a period of 3 months. Clinical evaluations such as corneal infiltration, edema and neovascularization were performed daily. At 3 months, the fibroplasias and collagen deposition were examined under light and scanning electron microscopy (SEM) and by immunohistochemical analysis.

RESULTSPretreatment of the discs obviously decreased conjunctival congestion, discharge, cornea edema, and the extent of neovascularization. More fibroblasts migrated into the pretreated discs than into the control, and collagen was deposited, indicating that the biocompatibility of the corneal replacements was enhanced by the chemical pretreatments. From immunohistochemical analysis, Type I collagen deposition in the pretreated silicone discs was greater than in the control.

CONCLUSIONSChemical treatment of silicone gel is effective in decreasing rabbit corneal inflammation, encouraging fibroblast in-growth, and enhancing tissue compatibility. Pretreated gels show good biological stability when used as a skirt material in Keratoprosthesis (Kpros).

Animals ; Biocompatible Materials ; adverse effects ; chemistry ; Cornea ; drug effects ; ultrastructure ; Corneal Edema ; etiology ; Corneal Stroma ; drug effects ; Microscopy, Electron, Scanning ; Porosity ; Prostheses and Implants ; Rabbits ; Silicone Gels ; adverse effects ; chemistry

Recent progress in chemotherapy has prolonged the survival of patients with malignant biliary strictures, leading to increased rates of stent occlusion. Even we employed metallic stents which contributed to higher rates and longer durations of patency, and occlusion of covered metallic stents now occurs in about half of all patients during their survival. We investigated the complication and patency rate for the removal of covered metallic stents, and found that the durations were similar for initial stent placement and re-intervention. In order to preserve patient quality of life, we currently recommend the use of covered metallic stents for patients with malignant biliary obstruction because of their removability and longest patency duration, even though uncovered metallic stents have similar patency durations.
Biliary Tract Diseases/*surgery ; Coated Materials, Biocompatible ; Device Removal ; Drainage/methods ; Endoscopy ; Foreign-Body Migration/surgery ; Humans ; Metals ; Postoperative Complications/surgery ; *Stents/adverse effects