Comparison of Rat Connective Tissue Response to BioMTA, Angelus MTA, and Root MTA

Due to the widespread use of MTA in dentistry and various brands of this product, we decided to compare the three brands available in the country market by their biocompatibility. We divided 20 male Wistar rats into four groups. After local anesthesia and washing, we made two incisions on both sides (4 incisions in total). The experimental groups were Angelus MTA (Angelus, Brazil), BioMTA (CERKAMED, Poland), Root MTA (Dr. Lotfi, Tabriz, Iran), and the control group. The resulting paste was placed in a tube and implanted subcutaneously into male Wistar rats. Wistar rats were sacrificed 7, 15, 30, and 60 days later, with high anesthetic doses. The sample implanted in 10% formalin was stabilized after tissue processing and H&E staining under a microscope. The inflammatory reaction in the tissues received different scores at the beginning of the tube opening. BioMTA had the highest inflammatory response among the groups, but the difference was not statistically significant ( p > 0.05). Also, there was no significant difference between the groups’ granulation and calcification ( p < 0.05). There was a significant difference between BioMTA, Angelus MTA, Root MTA, and control groups in fibrous capsule formation ( p < 0.05). Angelus MTA showed the lowest mean fibrous capsule formation in all periods. The effects of Angelus MTA, Root MTA, and BioMTA on connective tissue were investigated and compared. According to this study, these materials have good biocompatibility. According to the findings and statistical analysis, Angelus MTA has the most biocompatibility.

Estudo histológico do polímero poliuretano da mamona implantado no ângulo mandibular de ratos

Ricinoleic acid polyurethane polymer behaviour, implanted subperiostic in rat's mandibular angles was studied. liventy Rattus novergicus (Alhinus rodentia mammalia, cepa Wistar) were divided in for groups of five animals each. The polymer polyurethane, added of calcium carbonate, was implanted at mandibular angle of them. One animal from and 90 days after surgery. Histological examination showed the stability of the implant, the almost total absence of inflammatory response, the fibrous capsule formed surrounding the implant, and bone neoformation. According the experimental model, we concluded that the subperiostic implanted ricinoleic acid polyurethane polymer did not unleash a significant later inflammatory reaction, it has took to the development of a districted fibrous capsule, with evolution for bone neoformation. Signals of rejection, exposition or expel of the implant were not registered.

Defining Double Capsules: A Clinical and Histological Study

Background Macrotextured breast implants are associated with double capsules. There is little agreement as to what defines double capsules, how they present, and whether different degrees of double capsule exist. Objectives This study aimed to define double capsules and report an association between double-capsule type and degree of tissue adherence. Methods Consecutive aesthetic patients undergoing explantation of Biocell (Allergan, Inc., Irvine, CA) implants between May 2018 and November 2018 were included if they were found to have double capsules intraoperatively. Patient demographics, implant characteristics, explantation reason, implant adherence, and intraoperative findings were recorded. Both adherent and double capsules were histologically examined. Data were analyzed by descriptive statistics. Results Eleven patients had 22 Biocell implants explanted during the study period. The average explantation time was 8.0 years. Sixteen implants were found to have some degree of nonadherence, and all areas of nonadherence were associated with double-capsule formation. Double capsules were either partial or complete. The architecture of the inner layer of double capsules varied between an organized capsular layer and a thin area of nascent capsule. Histologically, all capsular specimens demonstrated an overall hypocellular fibrous capsule with scattered chronic inflammatory infiltrates. Synovial metaplasia was present in all capsule types and spaces/cracks in the capsule were disproportionately represented in partially adherent capsules. Conclusions This is the first study to identify a clinical and pathological correlation between double capsules and failed tissue adherence. Double capsules represent a spectrum of inner capsule formation ranging between nascent capsular tissue to a mature inner capsular layer. Level of Evidence: 4

Fibrin Polymer on the Surface of Biomaterial Implants Drives the Foreign Body Reaction

ABSTRACTImplantation of biomaterials and medical devices in the body triggers the foreign body reaction (FBR) which is characterized by macrophage fusion at the implant surface leading to the formation of foreign body giant cells and the development of the fibrous capsule enveloping the implant. While adhesion of macrophages to the surface is an essential step in macrophage fusion and implanted biomaterials are known to rapidly acquire a layer of host proteins, a biological substrate that is responsible for this process in vivo is unknown. Here we show that mice with genetically-imposed fibrinogen deficiency display a dramatic reduction of macrophage fusion on implanted biomaterials and are protected from the formation of fibrin-containing granulation tissue, a precursor of the fibrous capsule. Furthermore, macrophage fusion on biomaterials implanted in FibAEK mice that express a mutated form of fibrinogen incapable of thrombin-mediated polymerization was strongly reduced. Surprisingly, despite the lack of fibrin, the capsule was formed in FibAEK mice, although it had a different composition and distinct mechanical properties than that in wild-type mice. Specifically, while mononuclear α-SMA-expressing macrophages embedded in the capsule of both strains of mice secreted collagen, the amount of collagen and its density in the tissue of FibAEK mice was reduced. These data identify fibrin polymer as a key biological substrate driving the development of the FBR.

The peritumoral hypointense rim around hepatocellular carcinoma on T2*-weighted magnetic resonance imaging: radiologic–pathologic correlation

Background A peritumoral hypointense rim (PTHR) is sometimes observed around hepatocellular carcinoma (HCC) on T2*-weighted images (T2*WIs). We aimed to investigate the association between the PTHR and histopathologic findings on T2*WIs. Methods We assessed the presence of a PTHR on T2*WIs in 39 pathologically proven HCCs from April 2012 to December 2013. Prussian blue staining was performed, and iron deposition was evaluated by semiquantitative and quantitative methods. Optical density was used in the quantitative methods. The associations between a PTHR on T2*WI and histopathologic peritumoral or background liver iron deposition were analyzed. Results A PTHR on T2*WI was observed in 23 of 39 (59%) HCCs. There was no significant difference in the histopathologic fibrous capsule findings (P = 0.394). In the semiquantitative methods, both peritumoral and background liver iron deposition grade were significantly higher in HCCs with a PTHR compared with HCCs without a PTHR (P < 0.001). The mean optical density in HCCs with a PTHR was significantly higher compared with HCCs without a PTHR, in the quantitative peritumoral (42,244.1 ± 20,854.9 vs. 18,739.1 ± 12,258.7, respectively; P < 0.001) and background liver iron deposition analyses (35,554.7 ± 19,854.8 vs. 17,292.4 ± 11,605.8, respectively; P < 0.001). Tumor size (P = 0.005), etiology (P = 0.001), and degree of fibrosis (P = 0.042) were significantly associated with the presence of a PTHR. Conclusions A PTHR in HCCs on T2*WIs was strongly associated with peritumoral iron deposition in the iron-deposited background liver but not with the fibrous capsule.

The peritumoral hypointense rim around hepatocellular carcinoma on T2*-weighted magnetic resonance imaging: radiologic-pathologic correlation

Background: A peritumoral hypointense rim (PTHR) is sometimes observed around hepatocellular carcinoma (HCC) on T2*-weighted images (T2*WIs). We aimed to investigate the association between the PTHR and histopathologic findings on T2*WIs.Methods: We assessed the presence of a PTHR on T2*WIs in 39 pathologically proven HCCs from April 2012 to December 2013. Prussian blue staining was performed, and iron deposition was evaluated by semiquantitative and quantitative methods. Optical density was used in the quantitative methods. The associations between a PTHR on T2*WI and histopathologic peritumoral or background liver iron deposition were analyzed.Results: A PTHR on T2*WI was observed in 23 of 39 (59%) HCCs. There was no significant difference in the histopathologic fibrous capsule findings (P = 0.394). In the semiquantitative methods, both peritumoral and background liver iron deposition grade were significantly higher in HCCs with a PTHR compared with HCCs without a PTHR (P < 0.001). The mean optical density in HCCs with a PTHR was significantly higher compared with HCCs without a PTHR, in the quantitative peritumoral (42244.1 ± 20854.9 vs 18739.1 ± 12258.7, respectively; P < 0.001) and background liver iron deposition analyses (35554.7 ± 19854.8 vs 17292.4 ± 11605.8, respectively; P < 0.001). Tumor size (P = 0.005), etiology (P = 0.001), and degree of fibrosis (P = 0.042) were significantly associated with the presence of a PTHR.Conclusions: A PTHR in HCCs on T2*WIs was strongly associated with peritumoral iron deposition in the iron-deposited background liver but not with the fibrous capsule.

Subcutaneous Implantation Assessment of New Calcium-Silicate Based Sealer for Warm Obturation

Calcium silicate-based sealers were recently introduced as a new class of endodontic sealers, with potential further benefits due to their bioactivity. The aim of this study was to evaluate the biocompatibility of two new hydraulic calcium silicate-based sealers, TotalFill BC Sealer (FKG, La Chaux-des-Fonds, Switzerland) and TotalFill BC Sealer HiFlow (FKG, La Chaux-des-Fonds, Switzerland) through subcutaneous implantation in connective tissue of rats. Subcutaneous implantation was performed in 16 young Wistar rats. Four polyethylene tubes were implanted in each animal, one empty to serve as a control, and three filled with tested sealers: AH Plus as reference (Dentsply DeTrey, Konstanz, Germany), TotalFill BC Sealer (BC) and TotalFill BC Sealer HiFlow (HiFlow). Eight rats were euthanized at 8 days and the remaining eight at 30 days. Hematoxylin-eosin staining was used to score the inflammatory reaction, macrophage infiltrate and to measure the thickness of the fibrous capsule. von Kossa staining was performed to evaluate the mineralization level. Kruskal–Wallis test followed by Dunn’s post hoc test was used to analyze non-parametric data. To analyze the influence of the implantation time within each material, a Mann–Whitney U test was performed. At eight days post-implantation, AH Plus induced a more intense inflammatory reaction when compared both with the control (p ≤ 0.001) and BC (p ≤ 0.01). HiFlow presented a higher score of macrophage infiltrate than control (p ≤ 0.01) and BC (p ≤ 0.05). The fibrous capsule thickness in this period was significantly higher for the BC group when compared to control (p ≤ 0.01) and AH Plus (p ≤ 0.05). The mineralization potential was higher for the HiFlow group when compared with the control (p ≤ 0.001) and AH Plus (p ≤ 0.001). At 30 days post-implantation, the score for the inflammatory reaction remained higher for the AH Plus group when compared both to control (p ≤ 0.01) and BC (p ≤ 0.001). The macrophage infiltrate of the HiFlow was significantly higher than control (p ≤ 0.001) and AH Plus groups (p ≤ 0.01), additionally, the fibrous capsule of the BC (p ≤ 0.001) and HiFlow (p ≤ 0.01) groups were both thicker than control. Mineralization potential was observed only on BC (p ≤ 0.05) and HiFlow groups (p ≤ 0.001), when compared to control). BC exhibited the best biocompatibility performance of all tested sealers and HiFlow provided the greatest induction of mineralized tissues. Both TotalFill BC Sealer and TotalFill BC Sealer HiFlow are biocompatible and show potential bioactivity when implanted in the subcutaneous tissue. Bioactivity was not found in AH Plus.

High-strength and fibrous capsule–resistant zwitterionic elastomers

The high mechanical strength and long-term resistance to the fibrous capsule formation are two major challenges for implantable materials. Unfortunately, these two distinct properties do not come together and instead compromise each other. Here, we report a unique class of materials by integrating two weak zwitterionic hydrogels into an elastomer-like high-strength pure zwitterionic hydrogel via a “swelling” and “locking” mechanism. These zwitterionic-elastomeric-networked (ZEN) hydrogels are further shown to efficaciously resist the fibrous capsule formation upon implantation in mice for up to 1 year. Such materials with both high mechanical properties and long-term fibrous capsule resistance have never been achieved before. This work not only demonstrates a class of durable and fibrous capsule–resistant materials but also provides design principles for zwitterionic elastomeric hydrogels.