Adverse Reactions Associated with Dermal Fillers in the Oral and Maxillofacial Region: A Venezuelan Experience.

BACKGROUND: Dermal facial fillers are increasingly popular. Published reports on the clinical and histopathologic characteristics related to adverse reactions to dermal fillers in the facial region have been relatively well documented. This study adds to the literature on adverse reactions to injected filler in the oral and maxillofacial region in a South American population. METHODS: A retrospective, descriptive cross-sectional study (2019-2020) was performed. The study population was a dermatology service in Venezuela. Clinical and histopathologic features of patients with adverse effects were documented. RESULTS: A total of 35 cases of adverse reactions associated with cosmetic filler procedures were diagnosed during the analyzed period; of these, six cases (17.1%) involved the oral and maxillofacial region. All cases occurred in women. The mean age at diagnosis was 59.3 years (58-73). In three cases, dermal fillers were used in different locations on the face, while three involved the lips. Five patients exhibited adverse reactions to lip filler. All six cases were histopathologically diagnosed as foreign body reactions to injected material. Four and two cases revealed microscopic features compatible with hyaluronic acid and polymethylmethacrylate, respectively. CONCLUSION: Reflecting the dramatic increase in cosmetic procedures with soft tissue fillers, this study contributed by reporting six cases of foreign body reaction involving the oral and maxillofacial region, confirmed with biopsy and histopathology.

Amitriptyline efficacy in decreasing implant-induced foreign body reaction.

Beyond its actions on the nervous system, amitriptyline (AM) has been shown to lower inflammatory, angiogenic, and fibrogenic markers in a few pathological conditions in human and in experimental animal models. However, its effects on foreign body reaction (FBR), a complex adverse healing process, after biomedical material implantation are not known. We have evaluated the effects of AM on the angiogenic and fibrogenic components on a model of implant-induced FBR. Sponge disks were implanted subcutaneously in C57BL/6 mice, that were treated daily with oral administration of AM (5 mg/kg) for seven consecutive days in two protocols: treatment was started on the day of surgery and the implants were removed on the seventh day after implantation and treatment started 7 days after implantation and the implants removed 14 after implantation. None of the angiogenic (vessels, Vascular endothelial growth factor (VEGF), and interleukin-1ß (IL-1ß) or fibrogenic parameters (collagen, TGF-ß, and fibrous capsule) and giant cell numbers analyzed were attenuated by AM in 7-day-old implants. However, AM was able to downregulate angiogenesis and FBR in 14-day-old implants. The effects of AM described here expands its range of actions as a potential agent capable of attenuating fibroproliferative processes that may impair functionality of implantable devices.

Lesiones perirradiculares persistentes: revisión narrativa / Persistent periradicular lesions: a narrative review

La persistencia de lesiones perirradiculares luego del tra- tamiento endodóntico es un problema que requiere del clínico un conocimiento cabal de la histofisiología y de la histopato- logía del sistema de conductos radiculares del tejido pulpar y de los tejidos perirradiculares (periodonto y hueso); además de considerar siempre la posible existencia de enfermedades sistémicas que también pueden actuar como factores de in- fluencia. La presencia de bacterias remanentes a posteriori del tratamiento es considerada como una de las causas principales y más frecuentes para la perpetuación de las lesiones perirra- diculares. Sin embargo, existen otros factores causales, como la existencia de conductos laterales o accesorios infectados y no tratados, la reabsorción dentinaria interna, intercomunica- ciones, cul-de-sacs o istmos; que representan áreas de difícil acceso durante la instrumentación e irrigación. Cuando la cau- sa original se localiza en la zona perirradicular, como en los casos de actinomicosis, reacciones a cuerpo extraño, cristales de colesterol (CRCo) y granulomas o quistes con alto conte- nido de CRCo, la indicación más adecuada es el retratamiento y la cirugía periapical como complemento (AU)

The persistence of periradicular lesions after endodontic treatment is a problem that requires the doctor to have a thor- ough knowledge of the histophysiology and histopathology of the root canal system, the pulp tissue and periradicular tis- sues (periodontium and bone); as well as always considering the possible existence of systemic alterations that can also be influencing factors. Persisting bacteria within the root canal system after treatment is one of the major and most frequent causes for the perpetuation of periradicular lesions. Howev- er, there are other possible causal factors such as the exist- ence of untreated lateral or accessory canals, internal dentin resorption, intercommunications, cul-de-sacs or isthmuses; areas that represent a difficulty in access during instrumen- tation and irrigation. If the original cause is located in the periradicular area, in cases like actinomycosis, foreign-body reactions, cholesterol crystals (CRCo) and granulomas or cysts with high content of CRCo, retreatment coupled with periapical surgery is the best approach to treatment (AU)

ST2 deletion accelerates inflammatory-angiogenesis and remodeling in subcutaneous implants in mice.

Implantation of biomedical/synthetic devices to replace and/or repair biological tissues very often induces an adverse healing response (scarce angiogenesis, excessive collagen deposition) which is detrimental to implant functionality and integration to host tissue. Interleukin-33/ST2 axis (IL-33/ST2) has been shown to modulate angiogenic and remodeling processes in several types of injuries. However, its effects on these processes after implantation of synthetic matrix have not been reported. Using synthetic matrix of polyether-polyurethane implanted subcutaneously in mice lacking ST2 receptor (ST2/KO), we characterized neovascularization and matrix remodeling in the fibrovascular tissue induced by the implants. Tissue accumulation was increased inside and around the implants in KO implants relative to the wild type (WT). More intense proliferative activity, using CDC 47 marker, was observed in KO implants compared with that of WT implants. Angiogenesis, using two endothelial cell markers, Von Willebrand Factor (VWF) and vascular endothelial cell VE cadherin and hemoglobin content, increased in implants of KO mice relative to control WT. Remodeling of the newly formed fibrovascular tissue (soluble collagen and PicroSirius Red-stained histological sections) showed predominance of type 1 collagen in ST2-KO implants versus type 3 in control implants. The number of positive cells for caspase-3, apoptotic marker, decreased in ST2 group. Our findings evidenced a role of IL-33/ST2 axis in restraining blood vessel formation and regulating the pattern of matrix remodeling in the fibrovascular tissue induced by synthetic implants. Intervention in this cytokine complex holds potential to accelerate integration of biomaterial and host tissue by improving blood supply and matrix remodeling.

Comparative clinical evaluation of breast augmentation using silicone foam coated implants and textured implants.

PURPOSE: To evaluate whether silicone foam implants have a different evolution pattern compared to conventional texture implants. METHODS: Fifty-eight female patients underwent surgery. They were divided into two groups (silicone foam - Lifesil® - and microtexturized silicone - Lifesil®). The evolution was analyzed in postoperative consultations, with physical examination, photographic documentation and filling in a satisfaction questionnaire, in the postoperative period of one month, four months, one year and then annually, up to a maximum of 3 years of follow-up. RESULTS: There were no statistically significant differences in presence of rippling, stretch marks, breast ptosis, capsular contracture and quality of scars. There was a higher rate of patients who were very satisfied with the outcome 360 days after surgery in the group receiving silicone foam implants (p = 0.036). CONCLUSION: In short time, silicone foam envelope implants proved to be as reliable as textured silicone envelope implants, making them an option for augmentation mammoplasty.

Does a bilateral polypropylene mesh alter the duct deferens morphology, testicular size and testosterone levels? Experimental study in rats.

PURPOSE: To evaluate the effect of a PP mesh on duct deferens morphology, testicular size and testosterone levels. METHODS: Forty adult male rats were distributed into groups: 1) no surgery; 2) inguinotomy; 3) mesh placed on the duct deferens; and 4) mesh placed on the spermatic funiculus. After 90 postoperative days, the inguinal region was resected, and blood samples were collected for the measurement of serum testosterone (pg/dl). The ducts deferens were sectioned in three axial sections according to the relationship with the mesh - cranial, medial and caudal. The wall thickness and duct deferens lumen area were measured. RESULTS: The morphology of the duct deferens was preserved in all groups. The mesh placement did not alter this morphology in any of the analyzed segments. Surgery, with or without mesh placement, did not alter the morphology, wall thickness or lumen area (p>0.05). In all operated groups, serum testosterone levels were similar (p>0.05) but there was a decrease in testicle size (p<0.05). CONCLUSION: Surgery, with or without mesh placement, did not alter the morphology of the duct deferens and, although this treatment resulted in testicular size reduction, it did not affect serum testosterone levels.

Comparative clinical evaluation of breast augmentation using silicone foam coated implants and textured implants

Abstract Purpose To evaluate whether silicone foam implants have a different evolution pattern compared to conventional texture implants. Methods Fifty-eight female patients underwent surgery. They were divided into two groups (silicone foam - Lifesil® - and microtexturized silicone - Lifesil®). The evolution was analyzed in postoperative consultations, with physical examination, photographic documentation and filling in a satisfaction questionnaire, in the postoperative period of one month, four months, one year and then annually, up to a maximum of 3 years of follow-up. Results There were no statistically significant differences in presence of rippling, stretch marks, breast ptosis, capsular contracture and quality of scars. There was a higher rate of patients who were very satisfied with the outcome 360 days after surgery in the group receiving silicone foam implants (p = 0.036). Conclusion In short time, silicone foam envelope implants proved to be as reliable as textured silicone envelope implants, making them an option for augmentation mammoplasty.

Does a bilateral polypropylene mesh alter the duct deferens morphology, testicular size and testosterone levels? Experimental study in rats

Abstract Purpose To evaluate the effect of a PP mesh on duct deferens morphology, testicular size and testosterone levels. Methods Forty adult male rats were distributed into groups: 1) no surgery; 2) inguinotomy; 3) mesh placed on the duct deferens; and 4) mesh placed on the spermatic funiculus. After 90 postoperative days, the inguinal region was resected, and blood samples were collected for the measurement of serum testosterone (pg/dl). The ducts deferens were sectioned in three axial sections according to the relationship with the mesh — cranial, medial and caudal. The wall thickness and duct deferens lumen area were measured. Results The morphology of the duct deferens was preserved in all groups. The mesh placement did not alter this morphology in any of the analyzed segments. Surgery, with or without mesh placement, did not alter the morphology, wall thickness or lumen area (p>0.05). In all operated groups, serum testosterone levels were similar (p>0.05) but there was a decrease in testicle size (p<0.05). Conclusion Surgery, with or without mesh placement, did not alter the morphology of the duct deferens and, although this treatment resulted in testicular size reduction, it did not affect serum testosterone levels.

Tissue reaction after subcutaneous implants of a new material composed of ethylene-vinyl acetate and starch for future use as a biomaterial.

This study aimed to evaluate the tissue reaction of ethylene-vinyl acetate (EVA) in 4 different compositions and processing: EVA foamed at high pressure with ultrasound (EVACU); EVA with 15% starch foamed at high pressure with ultrasound (EVAMCU); EVA with 15% starch foamed at high pressure without ultrasound and EVA foamed at high pressure without ultrasound as future use as a porous scaffold. Scanning electron microscopy images showed the influence of starch, reducing the diameter of pores. The number of open pores was also reduced with the addition of starch. The ultrasound applied during the manufacturing of composites does not affect these characteristics. Eighteen rats were used to test the tissue reaction of materials and PTFE (polytetrafluoroethylene), proven biocompatible material. After 7, 15, and 60 days of surgery, the materials were removed and processed for microscopic evaluation and counting of the inflammatory infiltrate. The data shows inflammatory reaction similar to PTFE. However, in the quantitative analysis at 60 days, the EVACU and EVAMCU showed less quantity of mononuclear cells (p < 0.05). Thus, the results suggest that the use of ultrasound in the production method (EVA) seems to have improved cell behavior regarding the reduction of infiltration over the period, with tissue response equivalent to the PTFE. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 107B: 400-407, 2019.

Characterization of the T-cell response to polypropylene mesh in women with complications.

BACKGROUND: Polypropylene mesh is used widely for surgical treatment of pelvic organ prolapse and stress urinary incontinence. Although these surgeries demonstrate favorable functional and anatomic outcomes, their use has been limited by complications, the 2 most common being exposure and pain. Growing evidence suggests that T lymphocytes play a critical role in the regulation of the host response to biomaterials. OBJECTIVE: The purpose of this study was to define and characterize the T-cell response and to correlate the response to collagen deposition in fibrotic capsules in mesh tissue complexes that are removed for the complications of pain vs exposure. STUDY DESIGN: Patients who were scheduled to undergo a surgical excision of mesh for pain or exposure at Magee-Women's Hospital were offered enrollment. Forty-two mesh-vagina tissue complexes were removed for the primary complaint of exposure (n=24) vs pain (n=18). Twenty-one patients agreed to have an additional vaginal biopsy away from the site of mesh that served as control tissue. T cells were examined via immunofluorescent labeling for cell surface markers CD4+ (Th), CD8+ (cytotoxic) and foxp3 (T-regulatory cell). Frozen sections were stained with hematoxylin-eosin for gross morphologic condition and picrosirius red for collagen fiber analysis. Interrupted sodium-dodecyl sulfate gel electrophoresis was used to quantify the content of collagens type I and III, and the collagen III/I ratio. Transforming growth factor-ß and connective tissue growth factor, which are implicated in the development of fibrosis, were measured via enzyme-linked immunosorbent assays. Data were analyzed with the Student's t tests, mixed effects linear regression, and Spearman's correlation coefficients. RESULTS: Demographic data were not different between groups, except for body mass index, which was 31.7 kg/m2 for the exposure group and 28.2 kg/m2 for pain (P=.04). Tissue complexes demonstrated a marked, but highly localized, foreign body response. We consistently observed a teardrop-shaped fibroma that encapsulated mesh fibers in both pain and exposure groups, with the T cells localized within the tip of this configuration away from the mesh-tissue interface. All 3 T-cell populations were significantly increased relative to control: CD4+ T helper (P<.001), foxp3+ T regulatory (P<.001), and CD8+ cytotoxic T cell (P=.034) in the exposure group. In the pain group, only T-helper (P<.001) and T-regulatory cells (P<.001) were increased, with cytotoxic T cells (P=.520) not different from control. Picrosirius red staining showed a greater area of green (thin) fibers in the exposure group (P=.025) and red (thick) fibers in the pain group (P<.001). The ratio of area green/(yellow + orange + red) that represented thin vs thick fibers was significantly greater in the exposure group (P=.005). Analysis of collagen showed that collagen type I was increased by 35% in samples with mesh complications (exposure and pain) when compared with control samples (P=.043). Strong correlations between the profibrosis cytokine transforming growth factor-ß and collagen type I and III were found in patients with pain (r≥0.833; P=.01) but not exposure (P>.7). CONCLUSION: T cells appear to play a critical role in the long-term host response to mesh and may be a central pathway that leads to complications. The complexity of this response warrants further investigation and has the potential to broaden our understanding of mesh biology and clinical outcomes.

Pro - inflammatory cytokines and metalloproteinase activation in polypropylene mesh implant in rat subcutaneous tissue

ABSTRACT Aims and Objectives: Polypropylene meshes have been increasingly adopted for correction of pelvic organ prolapse due to its lower recurrence rate when compared to surgeries without meshes. The study of the interaction of these materials with the host tissue may contribute to the development of materials with best biocompatibility and, consequently, less complication rates. Materials and Methods: The present study compares the inflammatory reaction of standard-weight (SW) and lightweight (LW) meshes (72 g/m216g/m2 respectively), implanted in the abdomen of 20 adult rats, which were euthanized in four or 30 days. Quantification of pro-inflammatory markers, IL-1 and TNF-α, and of metalloproteinases, MMP2 and MMP3, were carried out through immunohistochemistry with AxioVision® software. Results: There were no significant differences in the quantification of IL-1 and TNF-α in LW versus SW meshes. However, IL-1 quantification increased along time (30 days >4 days, p=0.0269). Also, MMP-2 quantification was similar to SW and LW and both presented a significant increase along time (30 days >4 days, p <0.0001). MMP-3 quantification also showed no difference between the SW and LW groups, but increased along time (30 days >4 days, p=0.02). Conclusions: Mesh's density did not influence the quantification of pro-inflammatory cytokines IL-1 and TNF-α and metalloproteinases 2 and 3. The increased expression of IL-1, MMP-2 and MMP-3 over time could represent a longstanding inflammatory response after PP mesh implantation. Possibly, the occurrence of adverse events following PP prosthetic implants can be influenced by other factors, not solely related to the amount of implanted material.

Idiosyncratic reaction after injection of polyacrylate - polyalcohol copolymer

ABSTRACT Context: Polyacrylate-polyalcohol copolymer is a synthetic product, non-biodegradable, with low rate of therapeutic failure and lower incidence of reactions at the site of injection, when compared to biodegradable agents. We report an unprecedent, exuberant and persistent inflammatory reaction following injection of that substance. Patient: a 17 years-old patient with vesico-ureteral reflux and complete pyelocaliceal right duplication was submitted to treatment with polyacrylate-polyalcohol copolymer (STING technique). In the seventh day of post-operatory, she presented intense dysuria and hypogastric pain, without laboratory exams alterations; a symptomatic treatment was started. After two months, the symptoms persisted and an ultrasound detected thickening of bladder wall close to the uretero-vesical junction. After that exam, a cystostopic biopsy showed epithelial hyperplasia with increased edema of lamina propria, suggesting an adverse reaction to the polymer. After four months, there was complete remission, but the reflux persisted with the same grade. Hypothesis: This is an unprecedent reaction following injection of this copolymer. The presence of characteristics such as absence of infection, temporal relation between treatment and beginning of symptoms, and detection of epithelial hyperplasia at the local of injection reinforce the hypothesis of association of the substance and adverse reaction. In that patient, important complains motivated early investigation of urinary tract, that confirmed those aspects. Maybe if that reaction had occurred in patients with lower capacity of expression (such as in infants) it would be unnoticed.

Pro - inflammatory cytokines and metalloproteinase activation in polypropylene mesh implant in rat subcutaneous tissue.

AIMS AND OBJECTIVES: Polypropylene meshes have been increasingly adopted for correction of pelvic organ prolapse due to its lower recurrence rate when compared to surgeries without meshes. The study of the interaction of these materials with the host tissue may contribute to the development of materials with best biocompatibility and, consequently, less complication rates. MATERIALS AND METHODS: The present study compares the inflammatory reaction of standard-weight (SW) and lightweight (LW) meshes (72 g/m216g/m2 respectively), implanted in the abdomen of 20 adult rats, which were euthanized in four or 30 days. Quantification of pro-inflammatory markers, IL-1 and TNF-α, and of metalloproteinases, MMP2 and MMP3, were carried out through immunohistochemistry with AxioVision ® software. RESULTS: There were no significant differences in the quantification of IL-1 and TNF-α in LW versus SW meshes. However, IL-1 quantification increased along time (30 days >4 days, p=0.0269). Also, MMP-2 quantification was similar to SW and LW and both presented a significant increase along time (30 days >4 days, p < 0.0001). MMP-3 quantification also showed no difference between the SW and LW groups, but increased along time (30 days >4 days, p=0.02). CONCLUSIONS: Mesh's density did not influence the quantification of pro-inflammatory cytokines IL-1 and TNF-α and metalloproteinases 2 and 3. The increased expression of IL-1, MMP-2 and MMP-3 over time could represent a longstanding inflammatory response after PP mesh implantation. Possibly, the occurrence of adverse events following PP prosthetic implants can be influenced by other factors, not solely related to the amount of implanted material.

Lack of interferon-gamma attenuates foreign body reaction to subcutaneous implants in mice.

Subcutaneous implantation of synthetic materials and biomedical devices often induces abnormal tissue healing - the foreign body reaction-which impairs their function. In particular, Interferon-γ (IFN-γ) is a critical endogenous mediator of inflammation and plays a key role in a wide variety of biological responses including tissue healing. However, the contribution of endogenous IFN-γ on different features of the foreign body response induced by synthetic implants regarding neovascularization, inflammation, and fibrogenesis is not well known. Here, we evaluated inflammatory angiogenesis and fibrogenesis induced by implantation of polyether-polyurethane sponges in mice targeted disrupted of the interferon-γ gene (IFN-γ-/- ) and wild-type (WT). The hemoglobin content, the number of vessels, and blood flow (evaluated by LDPI-laser Doppler perfusion imaging) were decreased in the implants from IFN-γ-/- as compared to WT mice. Likewise, neutrophils and macrophages accumulation (MPO and NAG activities, respectively) was decreased in IFN-γ-/- implants. Interestingly, while the local content of VEGF, TNF-α, CXCL-1/KC, as measured by ELISA, and iNOS expression, as measured by qPCR, were significantly reduced, the content of IL-10 was greatly increased in the implants from IFN-γ-/- mice as compared to WT mice. No alterations were observed in CCL-2/MCP-1 levels. Lastly, the collagen deposition, assessed by Picro-Sirius red-stained histological sections, was also reduced in IFN-γ-/- implants. Altogether, these data suggest that IFN-γ activity contributes to inflammatory angiogenesis and fibrogenesis in synthetic implants and that lack of IFN-γ expression attenuates foreign body reaction to implants in mice. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 2243-2250, 2018.

Idiosyncratic reaction after injection of polyacrylate - polyalcohol copolymer.

CONTEXT: Polyacrylate-polyalcohol copolymer is a synthetic product, non-biodegradable, with low rate of therapeutic failure and lower incidence of reactions at the site of injection, when compared to biodegradable agents. We report an unprecedent, exuberant and persistent inflammatory reaction following injection of that substance. PATIENT: A 17 years-old patient with vesico-ureteral reflux and complete pyelocaliceal right duplication was submitted to treatment with polyacrylate-polyalcohol copolymer (STING technique). In the seventh day of post-operatory, she presented intense dysuria and hypogastric pain, without laboratory exams alterations; a symptomatic treatment was started. After two months, the symptoms persisted and an ultrasound detected thickening of bladder wall close to the uretero-vesical junction. After that exam, a cystostopic biopsy showed epithelial hyperplasia with increased edema of lamina propria, suggesting an adverse reaction to the polymer. After four months, there was complete remission, but the reflux persisted with the same grade. HYPOTHESIS: This is an unprecedent reaction following injection of this copolymer. The presence of characteristics such as absence of infection, temporal relation between treatment and beginning of symptoms, and detection of epithelial hyperplasia at the local of injection reinforce the hypothesis of association of the substance and adverse reaction. In that patient, important complains motivated early investigation of urinary tract, that confirmed those aspects. Maybe if that reaction had occurred in patients with lower capacity of expression (such as in infants) it would be unnoticed.

Repair of Bone Defects with Chitosan-Collagen Biomembrane and Scaffold Containing Calcium Aluminate Cement

Abstract Innovative biomaterials can provide a promising new direction for the treatment of bone defects, stimulating a proper repair process, with no damage to adjacent tissues. The purpose of this in vivo study was to evaluate the biocompatibility and the osteoinductive capacity of chitosan-collagen biomembrane and scaffold containing calcium aluminate cement. Eighteen New Zealand white rabbits (Oryctolagus cuniculus) were distributed according to the experimental times of analysis (7, 15 and 30 days). Four bone defects were created in the rabbits calvaria, which were individually filled with the biomembrane, scaffold, blood clot (negative control) and autologous bone (positive control). Histopathological analysis was performed using optical microscope at 32´, 64´, 125´ and 320´ magnifications. Cell response to inflammation and new bone tissue formation was quantified using a score system. The biomembrane group presented greater inflammatory response at 15 days, with significant difference to autologous bone group (p<0.05). There was no statistically significant difference for foreign body type reaction among groups (p>0.05). Concerning new bone formation, linear closure of the defect area was observed more evidently in the group with autologous bone. The scaffold group presented similar results compared with the autologous bone group at 30 days (p>0.05). Both tested biomaterials presented similar biocompatibility compared with the control groups. In addition, the biomembrane and scaffold presented similar osteoinductive capacity, stimulating bone repair process in the course of the experimental time intervals.

Resumo Biomateriais inovadores podem fornecer uma promissora nova direção para o tratamento de defeitos ósseos, estimulando um processo de reparo adequado, sem danos aos tecidos adjacentes. O objetivo deste estudo in vivo foi avaliar a biocompatibilidade e a capacidade osteoindutora de uma biomembrana e um scaffold compostos por colágeno e quitosana, contendo cimento de aluminato de cálcio. Dezoito coelhos (New Zealand White, Oryctolagus cuniculus) foram distribuídos de acordo com os períodos experimentais de análise (7, 15 e 30 dias). Quatro defeitos foram criados na calvaria dos coelhos, que foram individualmente preenchidos com a biomembrana, scaffold, coágulo (controle negativo) e osso autólogo (controle positivo). A avaliação histopatológica foi realizada em microscópio óptico em aumentos de 32´, 64´, 125´ e 320´. A resposta celular à inflamação e à formação de novo tecido ósseo foi quantificada utilizando um sistema de escore. O grupo da biomembrana apresentou maior resposta inflamatória no período de 15 dias, com diferença significativa para o grupo do osso autólogo (p<0,05). Não houve diferença estatística significante para a reação do tipo corpo estranho entre os grupos (p>0,05). Em relação à neoformação óssea, observou-se fechamento linear da área do defeito, que foi mais evidente no grupo em que se utilizou o osso autólogo. O grupo scaffold apresentou resultados semelhantes ao grupo do osso autólogo no período de 30 dias (p>0,05). Ambos os biomateriais testados apresentaram biocompatibilidade similar em comparação com os grupos controle. Além disso, a biomembrana e o scaffold apresentaram capacidade osteoindutora similar, estimulando o reparo ósseo ao longo dos intervalos de tempo experimentais.

Nitric oxide coating polypropylene mesh increases angiogenesis and reduces inflammatory response and apoptosis.

OBJECTIVES: To evaluate the effect of implanted S-nitrosoglutathione (GSNO) coating polypropylene mesh in foreign-body response of rats. METHODS: Thirty female rats underwent to subcutaneous implant of five polypropylene (PP) fragments: uncoated PP (control); PP polyvinylalcohol (PVA) coated and PP PVA + GSNO (1, 10 and 70 mMol) coated. After euthanasia (4 and 30 days), eight slides were prepared from each animal: hematoxylin-eosin (inflammatory response); unstained (birefringence collagen evaluation); TUNEL technique (apoptosis); and five for immunohistochemical processing: CD-31 (angiogenesis), IL-1 and TNF-α (proinflammatory cytokynes), iNOS (NO synthesis) and MMP-2 (collagen metabolism). The inflammation area, birefringence index, apoptotic index, immunoreactivity and vessel density were objectively measured. RESULTS: Inflammatory reaction area at 4 days was 11.3, 15.2, 25.1, 17.1 and 19.3% of pure PP, PVA, GSNO 1, 10 and 70 mM, respectively, p = 0.0006 (PP × Others). At 30 days lower inflammatory area was observed in GSNO 10 and 70 mM compared to pure PP (5.3, 5.2 and 11.1%, respectively, p = 0.0001). Vessel density was higher for GSNO 1 mM (25.5%) compared to pure PP (19.6%) at 30 days only, p = 0.0081. Apoptotic index at 4 days was lower for GSNO 1 mM (49.3%) than pure PVA (60.6%), p = 0.0124. GSNO 10 and 70 mM reduced their apoptotic index at 30 days compared to 4 days (49.9 vs. 36.9 and 59.1 vs. 47.5%, respectively, p = 0.0397). Birefringence index, IL-1, TNF, MMP-2 and iNOS were not different. CONCLUSIONS: Depending on concentrations, GSNO can increase angiogenesis, reduce inflammation and apoptosis compared to pure PP, without impact on cytokine, collagen organization/metabolism and endogenous NO synthesis.

Repair of Bone Defects with Chitosan-Collagen Biomembrane and Scaffold Containing Calcium Aluminate Cement.

Innovative biomaterials can provide a promising new direction for the treatment of bone defects, stimulating a proper repair process, with no damage to adjacent tissues. The purpose of this in vivo study was to evaluate the biocompatibility and the osteoinductive capacity of chitosan-collagen biomembrane and scaffold containing calcium aluminate cement. Eighteen New Zealand white rabbits (Oryctolagus cuniculus) were distributed according to the experimental times of analysis (7, 15 and 30 days). Four bone defects were created in the rabbits calvaria, which were individually filled with the biomembrane, scaffold, blood clot (negative control) and autologous bone (positive control). Histopathological analysis was performed using optical microscope at 32´, 64´, 125´ and 320´ magnifications. Cell response to inflammation and new bone tissue formation was quantified using a score system. The biomembrane group presented greater inflammatory response at 15 days, with significant difference to autologous bone group (p<0.05). There was no statistically significant difference for foreign body type reaction among groups (p>0.05). Concerning new bone formation, linear closure of the defect area was observed more evidently in the group with autologous bone. The scaffold group presented similar results compared with the autologous bone group at 30 days (p>0.05). Both tested biomaterials presented similar biocompatibility compared with the control groups. In addition, the biomembrane and scaffold presented similar osteoinductive capacity, stimulating bone repair process in the course of the experimental time intervals.

Histological evaluation of capsules formed by silicon implants coated with polyurethane foam and with a textured surface in rats

ABSTRACT PURPOSE: To assess the capsules formed by silicone implants coated with polyurethane foam and with a textured surface. METHODS: Sixty-four Wistar albinus rats were divided into two groups of 32 each using polyurethane foam and textured surface. The capsules around the implants were analyzed for 30, 50, 70 and 90 days. Were analyzed the following parameters: foreign body reaction, granulation tissue, presence of myofibroblasts, neoangiogenesis, presence of synovial metaplasia, capsular thickness, total area and collagen percentage of type I and III, in capsules formed around silicone implants in both groups. RESULTS: The foreign body reaction was only present in the four polyurethane subgroups. The formation of granulation tissue and the presence of myofibroblasts were higher in the four polyurethane subgroups. Regarding to neoangiogenesis and synovial metaplasia, there was no statistical difference between the groups. Polyurethane group presented (all subgroups) a greater capsule thickness, a smaller total area and collagen percentage of type I and a higher percentage area of type III, with statistical difference. CONCLUSION: The use of polyurethane-coated implants should be stimulated by the long-term results in a more stable capsule and a lower incidence of capsular contracture, despite developing a more intense and delayed inflammatory reaction in relation to implants with textured surface.

Foreign-Body Reaction and Osteolysis in Dorsal Lunate Dislocation Repair With Bioabsorbable Suture Anchor.

Background: In recent years the use of biodegradable suture anchors for treating tendon and ligament pathology in hand surgery became popular. These materials are biocompatible, radiolucent, and load sharing, as they incrementally transfer load to surrounding bone during the resorption process. Despite these numerous advantages, polyglycolic (PGA) and poly-L-lactic acid (PLLA) have become a problem because of the potential risk for foreign body reactions. Methods: This article presents a case of an intraosseous foreign body reaction and massive osteolysis of the proximal carpal after dorsal lunate dislocation repair with bioabsorbable suture anchors. Results: Because of the persistent pain and the decreased strength, a proximal row carpectomy was performed 12-months after the initial trauma. Conclusions: Hand surgeons should be aware of the possibility of a late foreign body reaction, that could be especially severe in carpal bones.