Sunscreen compound benzophenone-3 and its relationship with white blood cell counts.

BACKGROUND: Evidence from animal models suggests a role for the organic ultraviolet filter benzophenone-3's (BP-3) on white blood cells (WBCs). However, BP-3's effect on WBCs in humans is unknown. MATERIALS AND METHODS: We used National Health and Nutrition Examination Survey data from 2003 to 2016. We included participants >6 years with data on urinary BP-3, urinary creatinine, and WBC count. Quintiles of urinary creatinine-normalized BP-3 (CnBP-3) levels were used in linear regression models adjusting for age, gender, race, body mass index (BMI), smoking status, education level, family income to poverty threshold ratio, survey cycle, and season. RESULTS: Of the 16 959 participants, 8564 (50.5%) were females, 6602 (38.9%) were White, and 3870 (22.8%) were Black. The mean (standard deviation) age was 37.6 (22.7) years, BMI was 26.8 (7.40) kg/m2, WBC count was 7.22 (2.53) × 109/L, neutrophil count was 4.15 (1.86) × 109/L, and lymphocyte count was 2.25 (1.33) × 109/L and median (interquartile range) of CnBP-3 was 12.1 (44.9) µg/gm. The highest quintile of CnBP-3 was associated with significantly lower WBC and neutrophil counts compared to the lowest quintile of CnBP-3 (Δ quintiles = -137 × 106/L, 95% CI: -249 to -24, p = 0.02 and = -177 × 106/L, 95% CI: -323 to -30, p = 0.02, respectively). In contrast, we did not observe a difference in lymphocyte count between the lowest and highest quintiles of CnBP-3 in unadjusted or adjusted analyses. CONCLUSION: We found an inverse relationship between BP-3 levels and WBC and neutrophil counts, and not with lymphocyte count. Further research is needed to confirm our findings.

Concentrations, compositional profiles, and health risks of benzophenones among the Taiwanese population based on analysis of 23 daily consumed foods.

In this study, we analyzed the occurrence and distribution of 11 benzophenone-type ultraviolet filters (BPs) in 893 food samples spanning 7 food categories in Taiwan. We conducted a Monte Carlo simulation to determine the carcinogenic and noncarcinogenic risks of BPs. The results indicated that cornflakes had the highest mean level of BPs (103 ng/g), followed by bread (101 ng/g) and pastries (59 ng/g). BP was the most prevalent category, followed by 4-methylbenzophenone (4-MBP), 2-hydroxybenzophenone, and benzophenone-3. Estimation of the lifetime cancer risk (LTCR) of BP (average life expectancy of 80 years) placed them in the 50th and 97.5th percentiles [P50 (P97.5)] LTCR of 1.9 × 10-7 (5.7 × 10-6), indicating that BP in food poses a low renal hazard to the Taiwanese population. The noncarcinogenic risk of BPs was evaluated using a hazard quotient and combined margin of exposure (MOET), revealing a P50 (P97.5) hazard index of < 1 for BP, 4-MBP, and methyl-2-benzoylbenzoate. Although the P50 MOET values for all age groups were within the moderate range of concern, with a more conservative extreme (P2.5), the MOET values for the 0-3, 3-6, and 6-12 age groups fell below 100, indicating a high concern for renal degeneration and hyperplasia.

Evaluation of High-Performance Polyether Ether Ketone Polymer Treated with Piranha Solution and Epigallocatechin-3-Gallate Coating.

Background: Dental implantation has become a standard procedure with high success rates, relying on achieving osseointegration between the implant surface and surrounding bone tissue. Polyether ether ketone (PEEK) is a promising alternative to traditional dental implant materials like titanium, but its osseointegration capabilities are limited due to its hydrophobic nature and reduced surface roughness. Objective: The aim of the study is to increase the surface roughness and hydrophilicity of PEEK by treating the surface with piranha solution and then coating the surface with epigallocatechin-3-gallate (EGCG) by electrospraying technique. Materials and Methods: The study includes four groups intended to investigate the effect of piranha treatment and EGCG coating: a control group of PEEK discs with no treatment (C), PEEK samples treated with piranha solution (P), a group of PEEK samples coated with EGCG (E), and a group of PEEK samples treated with piranha solution and coated with EGCG (PE). Surface roughness, wettability, and microhardness were assessed through statistical analysis. Results: Piranha treatment increased surface roughness, while EGCG coating moderated it, resulting in an intermediate roughness in the PE group. EGCG significantly improved wettability, as indicated by the reduced contact angle. Microhardness increased by about 20% in EGCG-coated groups compared to noncoated groups. Statistical analysis confirmed significant differences between groups in all tests. Conclusion: This study demonstrates the potential of EGCG coating to enhance the surface properties of PEEK as dental implants. The combined piranha and EGCG modification approach shows promise for improved osseointegration, although further vivo research is necessary. Surface modification techniques hold the key to optimizing biomaterial performance, bridging the gap between laboratory findings and clinical implementation in dental implantology.

Mechanical failure of distal femur mega prosthesis due to polyaryl-ether-ether-ketone (PEEK) hinge component.

BACKGROUND: Polyaryl-ether-ether-ketone (PEEK) has gained popularity as a substrate for orthopaedic hardware due to its desirable properties such as heat and deformation resistance, low weight, and ease of manufacturing. However, we observed a relatively high failure rate of PEEK-based hinges in a distal femur reconstruction system. In this study, we aimed to evaluate the proportion of patients who experienced implant failure, analyse the mechanism of failure, and document the associated clinical findings. METHODS: We conducted a retrospective cohort study, reviewing the medical charts of 56 patients who underwent distal femur resection and reconstruction with a PEEK Optima hinge-based prosthesis between 2004 and 2018. Concurrently, we performed a clinical and biomechanical failure analysis. RESULTS: PEEK component failure occurred in 21 out of 56 patients (37.5%), with a mean time to failure of 63.2 months (range: 13-144 months, SD: 37.9). The survival distributions of PEEK hinges for males and females were significantly different (chi-square test, p-value = 0.005). Patient weight was also significantly associated with the hazard of failure (Wald's test statistic, p-value = 0.031). DISCUSSION: Our findings suggest that PEEK hinge failure in a distal femur reconstruction system is correlated with patient weight and male gender. Retrieval analysis revealed that failure was related to fretting and microscopic fractures due to cyclic loading, leading to instability and mechanical failure of the PEEK component in full extension. Further assessment of PEEK-based weight bearing articulating components against metal is warranted.

Environmentally relevant concentrations of benzophenones exposure disrupt intestinal homeostasis, impair the intestinal barrier, and induce inflammation in mice.

The aim of this study is to investigate the adverse effects of benzophenones (BPs) on the intestinal tract of mice and the potential mechanism. F1-generation ICR mice were exposed to BPs (benzophenone-1, benzophenone-2, and benzophenone-3) by breastfeeding from birth until weaning, and by drinking water after weaning until maturity. The offspring mice were executed on postnatal day 56, then their distal colons were sampled. AB-PAS staining, HE staining, immunofluorescence, Transmission Electron Microscope, immunohistochemistry, Western Blot and RT-qPCR were used to study the effects of BPs exposure on the colonic tissues of offspring mice. The results showed that colonic microvilli appeared significantly deficient in the high-dose group, and the expression of tight junction markers Zo-1 and Occludin was significantly down-regulated and the number of goblet cells and secretions were reduced in all dose groups, and the expression of secretory cell markers MUC2 and KI67 were decreased, as well as the expression of intestinal stem cell markers Lgr5 and Bmi1, suggesting that BPs exposure caused disruption of intestinal barrier and imbalance in the composition of the intestinal stem cell pool. Besides, the expression of cellular inflammatory factors such as macrophage marker F4/80 and tumor necrosis factor TNF-α was elevated in the colonic tissues of all dose groups, and the inflammatory infiltration was observed, which means the exposure of BPs caused inflammatory effects in the intestinal tract of F1-generation mice. In addition, the contents of Notch/Wnt signaling pathway-related genes, such as Dll-4, Notch1, Hes1, Ctnnb1and Sfrp2 were significantly decreased in each high-dose group (P < 0.05), suggesting that BPs may inhibit the regulation of Notch/Wnt signaling pathway. In conclusion, exposure to BPs was able to imbalance colonic homeostasis, disrupt the intestinal barrier, and trigger inflammation in the offspring mice, which might be realized through interfering with the Notch/Wnt signaling pathway.

Single and mixture effects of bisphenol A and benzophenone-3 on in vitro T helper cell differentiation.

Immune homeostasis is key to guarantee that the immune system can elicit effector functions against pathogens and at the same time raise tolerance towards other antigens. A disturbance of this delicate balance may underlie or at least trigger pathologies. Endocrine disrupting chemicals (EDCs) are increasingly recognized as risk factors for immune dysregulation. However, the immunotoxic potential of specific EDCs and their mixtures is still poorly understood. Thus, we aimed to investigate the effect of bisphenol A (BPA) and benzophenone-3 (BP-3), alone and in combination, on in vitro differentiation of T helper (TH)17 cells and regulatory T (Treg) cells. Naïve T cells were isolated from mouse lymphoid tissues and differentiated into the respective TH population in the presence of 0.001-10 µM BP-3 and/or 0.01-100 µM BPA. Cell viability, proliferation and the expression of TH lineage specific transcription factors and cytokines was measured by flow cytometry and CBA/ELISA. Moreover, the transcription of hormone receptors as direct targets of EDCs was quantified by RT-PCR. We found that the highest BPA concentration adversely affected TH cell viability and proliferation. Moreover, the general differentiation potential of both TH populations was not altered in the presence of both EDCs. However, EDC exposure modulated the emergence of TH17 and Treg cell intermediate states. While BPA and BP-3 promoted the development of TH1-like TH17 cells under TH17-differentiating conditions, TH2-like Treg cells occurred under Treg polarization. Interestingly, differential effects could be observed in mixtures of the two tested compounds compared with the individual compounds. Notably, estrogen receptor ß expression was decreased under TH17-differentiating conditions in the presence of BPA and BP-3 as mixture. In conclusion, our study provides solid evidence for both, the immune disruptive potential and the existence of cumulative effects of real nature EDC mixtures on T cell in vitro differentiation.

Effect of different surface roughening treatment on polyether ether ketone and acrylic resin bonding: A pilot study.

BACKGROUND: As polyether ether ketone (PEEK) is a relatively new material in dentistry, its bonding properties with regard to dental acrylic base materials are not fully known. To ensure the long-term success of removable dentures with a PEEK framework, the base materials must be well bonded to each other. OBJECTIVES: The study aimed to investigate the effects of different kinds of surface roughening treatment on PEEK and acrylic resin bonding. MATERIAL AND METHODS: Eighty PEEK specimens (N = 80) were randomly divided into 5 groups (n = 16 per group) and subjected to various surface roughening treatment (control, grinding, sandblasting, tribochemical silica coating (CoJet), and sulfuric acid etching). Heat-polymerized acrylic resin was applied to the treated surfaces of the PEEK specimens. The shear bond strength (SBS) test, environmental scanning electron microscopy (ESEM) analysis and three-dimensional (3D) surface topography analysis were performed. The statistical analysis of the data was conducted using the analysis of variance (ANOVA) and Tukey's multiple comparison test. RESULTS: The one-way ANOVA showed significant differences in the SBS values between the groups (p = 0.001). Sandblasting, tribochemical silica coating and sulfuric acid etching resulted in high SBS values (p = 0.001). The highest SBS values were observed in the sulfuric acid etching group (8.83 ±3.63 MPa), while the lowest SBS values were observed in the control group (3.33 ±2.50 MPa). CONCLUSIONS: The additional roughening treatment applied to the PEEK surface increases the bond strength with heat-polymerized acrylic resin.

Comparison of 3 Different Surgical Techniques for Rotator Cuff Repair in a Rabbit Model: Direct Suture, Inlay Suture, and Polyether Ether Ketone (PEEK) Suture Anchor.

BACKGROUND: Rotator cuff tears have been repaired using the transosseous method for decades. The direct suture (DS) technique has been widely used for rotator cuff tears; however, the retear rate is relatively high. Suture anchors are now used frequently for rotator cuff repair (RCR) in accordance with recent developments in materials. However, polyether ether ketone (PEEK) may still cause complications such as the formation of cysts and osteophytes. Some studies have developed the inlay suture (IS) technique for RCR. PURPOSE/HYPOTHESIS: To compare how 3 different surgical techniques-namely, the DS, IS, and PEEK suture anchor (PSA)-affect tendon-bone healing after RCR. We hypothesized that the IS technique would lead to better tendon-to-bone healing and that the repaired structure would be similar to the normal enthesis. STUDY DESIGN: Controlled laboratory study. METHODS: Acute infraspinatus tendon tears were created in 36 six-month-old male rabbits, which were divided into 3 groups based on the technique used for RCR: DS, IS, and PSA. Animals were euthanized at 6 and 12 weeks postoperatively and underwent a histological assessment and imaging. The expression of related proteins was demonstrated by immunohistochemistry and immunofluorescence staining. Mechanical properties were evaluated by biomechanical testing. RESULTS: At 12 weeks, regeneration of the enthesis was observed in the 3 groups. However, the DS group showed a lower type I collagen content than the PSA and IS groups, which was similar to the results for scleraxis. The DS group displayed a significantly inferior type II collagen expression and proteoglycan deposition after safranin O/fast green and sirius red staining. With regard to runt-related transcription factor 2 and alkaline phosphatase, the IS group showed upregulated expression levels compared with the other 2 groups. CONCLUSION: Compared with the DS technique, the PSA and IS techniques contributed to the improved maturation of tendons and fibrocartilage regeneration, while the IS technique particularly promoted osteogenesis at the enthesis. CLINICAL RELEVANCE: The IS and PSA techniques may be more beneficial for tendon-bone healing after RCR.

Aging processes in dental thermoplastics - Thermoanalytical investigations and effects on Vickers as well as Martens hardness.

OBJECTIVE: The influence of various aging protocols, representing and accelerating influences present in the dental context, on possible changes in the microstructure and mechanical properties of thermoplastics was investigated. In order to minimize the complexity of the systems, first pure polymers and then later the equivalent dental polymeric materials were analyzed. MATERIALS AND METHODS: Pure polymers (Poly(methyl methacrylate) - PMMA, Polyoxymethylene homopolymer - POM-H, Polyether ether ketone - PEEK, Nylon 12 - PA12, Polypropylene - PP) were analyzed before as well as after applying different aging protocols relevant to the oral environment (ethanol, thermocycling, alkaline and acidic setting) by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The thermoanalytical parameters used were glass transition temperature (Tg), melting peak and crystallization peak temperature (Tpm, Tpc) and decomposition behavior. In a second step selected commercially available dental products (Telio CAD - PMMAD, Zirlux Acetal - POMD, Juvora Natural Dental Disc - PEEKD) aged by the protocol that previously showed strong effects were examined and additionally tested for changes in their Vickers and Martens hardness by Mann-Whitney-U test. RESULTS: The combinations of pure polymers and viable aging protocols analyzed within this study were identified via TGA or DSC as PA12 & thermocycling, POM-H & denture cleanser/lactic acid/ethanol, PP & lactic acid. The dental polymeric materials PMMAD and POMD due to aging in lactic acid showed slight but significantly (p < 0.01) reduced Vickers and partly Martens hardness. PEEK showed the greatest material resistance within this study.

Interference with SPARC inhibits Benzophenone-3 induced ferroptosis in osteoarthritis: Evidence from bioinformatics analyses and biological experimentation.

The aim of this study is to conduct a thorough evaluation of the association between Benzophenone-3 (BP-3) exposure and OA, offering critical insights into the underlying mechanisms involved. The National Health and Nutrition Examination Survey (NHANES) database was utilized to investigate the correlation between BP-3 and osteoarthritis. Proteomic sequencing from clinical sample and the PharmMapper online tool were employed to predict the biological target of BP-3. Cellular molecular assays and transfection studies were performed to verify the prediction from bioinformatics analyses. Through cross-sectional analysis of the NHANES database, we identified BP-3 as a risk factor for OA development. The results of proteomic sequencing showed that Secreted Protein Acidic and Rich in Cysteine (SPARC) was significantly elevated in the area of damage compared to the undamaged area. SPARC was also among the potential biological targets of BP-3 predicted by the online program. Through in vitro cell experiments, we further determined that the toxicological effects of BP-3 may be due to SPARC, which elevates intracellular GPX4 levels, activates the glutathione system, and promotes lipid peroxidation to mitigate ferroptosis. Inhibiting SPARC expression has been shown to reduce inflammation and ferroptosis in OA contexts. This research provides an expansive understanding of BP-3's influence on osteoarthritis development. We have identified SPARC as a potent target for combating chondrocyte ferroptosis in BP-3-associated osteoarthritis.

The exposure to UV filters: Prevalence, effects, possible molecular mechanisms of action and interactions within mixtures.

Substances that can absorb sunlight and harmful UV radiation such as organic UV filters are widely used in cosmetics and other personal care products. Since humans use a wide variety of chemicals for multiple purposes it is common for UV filters to co-occur with other substances either in human originating specimens or in the environment. There is increasing interest in understanding such co-occurrence in form of potential synergy, antagonist, or additive effects of biological systems. This review focuses on the collection of data about the simultaneous occurrence of UV filters oxybenzone (OXYB), ethylexyl-methoxycinnamate (EMC) and 4-methylbenzylidene camphor (4-MBC) as well as other classes of chemicals (such as pesticides, bisphenols, and parabens) to understand better any such interactions considering synergy, additive effect and antagonism. Our analysis identified >20 different confirmed synergies in 11 papers involving 16 compounds. We also highlight pathways (such as transcriptional activation of estrogen receptor, promotion of estradiol synthesis, hypothalamic-pituitary-gonadal (HPG) axis, and upregulation of thyroid-hormone synthesis) and proteins (such as Membrane Associated Progesterone Receptor (MAPR), cytochrome P450, and heat shock protein 70 (Hsp70)) that can act as important key nodes for such potential interactions. This article aims to provide insight into the molecular mechanisms on how commonly used UV filters act and may interact with other chemicals.

Effect of topical bromfenac on intraretinal cystoid lesion in simultaneous cataract and idiopathic epiretinal membrane surgery.

PURPOSE: To investigate the effect of topical nonsteroidal anti-inflammatory drugs (NSAIDs,) bromfenac on the intraretinal cystic lesions (IRC) when performing simultaneous cataract and idiopathic epiretinal membrane (iERM) surgery. METHODS: This study included patients with iERM who had been followed up for 6 months after vitrectomy, membrane removal, and concurrent cataract surgery. Eyes were treated with topical bromfenac or not. The baseline fluorescein angiography (FA) was obtained to assess the microvascular leakage (ML). Structural changes of macula, including IRC and central macular thickness (CMT) were assessed using optical coherence tomography (OCT). The main outcome measures were changes in IRCs and best-corrected visual acuity (BCVA) regarding FA findings. RESULTS: One hundred eighteen eyes were included. IRC and ML were observed in 51 eyes (43.2%) and 63 eyes (53.4%), respectively. The IRC did not show any association with the ML. Of total, 29 eyes (24.6%) were treated with topical bromfenac (Group A). Compared to Group B, topical bromfenac did not show beneficial effects in aspect of preventions for the newly developed IRC and treatment for pre-existed IRC. Whether the ML existed or not, topical bromfenac did not show any different effect on the changes in BCVA and IRC. CONCLUSION: When performing simultaneous cataract and ERM surgery, topical NSAIDs, bromfenac did not show beneficial effects on the preventions and treatment of IRC in both eyes with and without the ML.

Benzophenone-3 alters expression of genes encoding vascularization and epithelial-mesenchymal transition functions during Trp53-null mammary tumorigenesis.

Benzophenone-3 (also referred to as oxybenzone) is a putative endocrine disrupting chemical and common ingredient in sunscreens and other personal care products. We previously showed that benzophenone-3 was promotional for epithelial tumorigenesis in mice fed adult high-fat diet, while protective against the incidence of more aggressive spindle cell tumors in the same treatment group. In this study, we show that benzophenone-3 reduces epithelial to mesenchymal transition in the epithelial tumors of these mice. This reduction in epithelial to mesenchymal transition is associated with altered expression of several genes involved in regulation of angiogenesis and epithelial to mesenchymal transition. Among the genes altered in expression, Timp1 is of particular interest because benzophenone-3 suppressed both migration and Timp1 expression in a mammary tumor cell line that displays epithelial to mesenchymal transition characteristics. These alterations in gene expression plausibly stabilize the vasculature of epithelial carcinomas and contribute to benzophenone-3 promotion of epithelial tumors, while at the same time suppress epithelial to mesenchymal transition and suppress incidence of spindle cell tumors.

The Effectiveness of Tritanium Cages in Preventing Osteolytic Vertebral Endplate Cysts After Lumbar Interbody Fusion.

OBJECTIVE: Lumbar interbody fusion (LIF) is a common surgical procedure, but postoperative complications, such as osteolytic vertebral endplate cysts, can adversely affect patient outcomes. This study aims to investigate whether tritanium cages (Stryker, Mahwah, New Jersey, USA) are effective in preventing osteolytic vertebral endplate cysts after LIF. METHODS: Clinical data from 8 years (2013-2020) of LIF procedures at our hospital were analyzed. Computed tomography was used to assess the formation of osteolytic vertebral endplate cysts 6 months after surgery. Clinical factors potentially associated with cyst formation were compared among 3 different interbody spacer materials: tritanium, titanium, and polyetheretherketone. RESULTS: LIF was performed for 169 patients at 205 spinal levels, employing tritanium cages in 56 levels (48 patients), titanium in 103 levels (86 patients), and polyetheretherketone in 46 levels (35 patients). At 6 months after LIF, 27.3% of patients showed worsening of osteolytic vertebral endplate cysts. Multivariate logistic regression analysis showed that tritanium cages (odds ratio [OR], 3.86; 95% confidence interval [CI], 1.46-10.21) and titanium (OR, 2.55; 95% CI, 1.13-5.75), and posterior LIF (OR, 5.74; 95% CI, 2.24-14.74) were associated with a reduced risk of postoperative osteolytic vertebral endplate cysts. CONCLUSIONS: Tritanium cages have shown promise in preventing postoperative osteolytic vertebral endplate cysts, suggesting their potential as a stable and effective choice in LIF procedures. These findings have significant implications for improving patient outcomes and warrant further investigation to optimize surgical techniques and materials.

Effects of Nd: YAG LASER irradiation and O2 plasma on the adhesive performance of poly-ether-ether-ketone (PEEK).

PURPOSE: To evaluate the effects of neodymium-doped yttrium aluminum garnet (Nd: YAG) LASER irradiation and oxygen (O2) plasma on the adhesive performance of polyether ether ketone (PEEK) and resin adhesive. METHODS: Nd: YAG LASERs of varying powers and O2 plasma for different durations were used to modify PEEK. A total of 168 PEEK specimens were randomly divided into seven groups (n = 24/group): (A) Control group: untreated PEEK, (B) L0.75 group: PEEK modified with 0.75 W Nd: YAG LASER, (C) L1 group: PEEK modified with 1.0 W Nd: YAG LASER, (D) L1.25 group: PEEK modified with 1.25 W Nd: YAG LASER, (E) P15 group: PEEK modified with 15 min of O2 plasma, (F) P25 group: PEEK modified with 25 min of O2 plasma, and (G) P35 group: PEEK modified with 35 min of O2 plasma. The surface characteristics of the materials were comprehensively analyzed using a scanning electron microscope (SEM), profilometer, energy-dispersive spectrometer (EDS), and contact angle tester. The adhesive specimens were bonded with Variolink N resin adhesive in all groups and each group was further divided into two subgroups (n = 12/group): (a) water storage for 56 h at 37 °C and (b) thermal cycling 5000 times. Shear bond strength (SBS) was tested using a universal testing machine, and the fracture modes were observed using an automated chemiluminescence analysis system to assess the effects of Nd: YAG LASER and O2 plasma on the bond strength of PEEK to resin adhesive. RESULTS: Both Nd: YAG LASER and O2 plasma treatments altered the surface characteristics of PEEK and significantly increased the SBS between PEEK and Variolink N resin adhesive. The L0.75 group (Nd: YAG LASER) and the P35 group (O2 plasma) achieved the highest SBS, respectively. Furthermore, the SBS of the L0.75 group was higher than that of the P35 group. Following thermal cycling, SBS values decreased compared to the water storage subgroups. The fracture modes of the specimens in each group were predominantly interfacial and mixed, with no cohesive fractures observed. CONCLUSIONS: Nd: YAG LASER irradiation and O2 plasma treatments can improve the SBS between PEEK and resin adhesive, with the 0.75 W Nd: YAG LASER being the preferred treatment method.

Influence of polyether ether ketone coping crown on the adaptation of implant abutment.

OBJECTIVE: To evaluate the influence of polyether ether ketone coping crown on the adaptation of implant abutment. Methods: The vitro study was conducted at the department of Prosthodontics, Hainan Stomatological Hospital, China, from October 2021 to March 2022, and comprised patients undergoing implant surgery on first molar. Patients were divided into two groups, with group A patients receiving polyether ether ketone coping crowns, and group B receiving zirconia crowns. Replica technique was used to replicate the gap between the crowns and the abutments. The thickness of the silicone film was measured under the stereomicroscope, and the gap between the groups was compared. Data was analysed using SPSS 22. RESULTS: In group A, mean marginal gap was 82.43±25.00µm, and mean overall gap was 85.45±33.75µm. In group B, the corresponding values were 65.09±11.69µm and 78.04±26.67µm. There was a significant difference in the adaptation between the groups at the marginal and overall measurement points (p<0.05). Conclusion: Marginal and internal adaptations of polyether ether ketone coping crown for abutment could be considered clinically acceptable.

Branching morphogenesis of the mouse mammary gland after exposure to benzophenone-3.

Pubertal mammary branching morphogenesis is a hormone-regulated process susceptible to exposure to chemicals with endocrine disruptive capacity, such as the UV-filter benzophenone-3 (BP3). Our aim was to assess whether intrauterine or in vitro exposure to BP3 modified the branching morphogenesis of the female mouse mammary gland. For this, pregnant mice were dermally exposed to BP3 (0.15 or 50 mg/kg/day) from gestation day (GD) 8.5 to GD18.5. Sesame oil treatment served as control. Changes of the mammary glands of the offspring were studied on postnatal day 45. Further, mammary organoids from untreated mice were cultured under branching induction conditions and exposed for 9 days to BP3 (1 × 10-6 M, 1 × 10-9 M, or 1 × 10-12 M with 0.01% ethanol as control) to evaluate the branching progression. Mice that were exposed to BP3 in utero showed decreased mRNA levels of progesterone receptor (PR) and WNT4. However, estradiol and progesterone serum levels, mammary histomorphology, proliferation, and protein expression of estrogen receptor alpha (ESR1) and PR were not significantly altered. Interestingly, direct exposure to BP3 in vitro also decreased the mRNA levels of PR, RANKL, and amphiregulin without affecting the branching progression. Most effects were found after exposure to 50 mg/kg/day or 1 × 10-6 M of BP3, both related to sunscreen application in humans. In conclusion, exposure to BP3 does not impair mammary branching morphogenesis in our models. However, BP3 affects PR transcriptional expression and its downstream mediators, suggesting that exposure to BP3 might affect other developmental stages of the mammary gland.

Methods to improve antibacterial properties of PEEK: A review.

As a thermoplastic and bioinert polymer, polyether ether ketone (PEEK) serves as spine implants, femoral stems, cranial implants, and joint arthroplasty implants due to its mechanical properties resembling the cortical bone, chemical stability, and radiolucency. Although there are standards and antibiotic treatments for infection control during and after surgery, the infection risk is lowered but can not be eliminated. The antibacterial properties of PEEK implants should be improved to provide better infection control. This review includes the strategies for enhancing the antibacterial properties of PEEK in four categories: immobilization of functional materials and functional groups, forming nanocomposites, changing surface topography, and coating with antibacterial material. The measuring methods of antibacterial properties of the current studies of PEEK are explained in detail under quantitative, qualitative, andin vivomethods. The mechanisms of bacterial inhibition by reactive oxygen species generation, contact killing, trap killing, and limited bacterial adhesion on hydrophobic surfaces are explained with corresponding antibacterial compounds or techniques. The prospective analysis of the current studies is done, and dual systems combining osteogenic and antibacterial agents immobilized on the surface of PEEK are found the promising solution for a better implant design.

Surface modification affects human gingival epithelial cell behavior on polyetheretherketone surfaces.

Gingival epithelial attachment to the abutment is important for the prevention of peri-implantitis. Polyetheretherketone (PEEK) has recently gained attention as an alternative material to titanium; however, it is biologically inert, which is disadvantageous for obtaining soft tissue sealing of the transmucosal part of the implant abutment. Therefore, ultraviolet (UV) irradiation, argon plasma irradiation, and buffing were selected as treatments to modify the PEEK surface. None of the treatments had any effect on the material's mechanical strength. The UV and plasma treatments did not significantly affect the surface morphology. Surface elemental analysis showed a decrease in carbon content and an increase in oxygen content and wettability for all treatments. Human gingival epithelial cell adhesion, proliferation, and the expression of adhesion proteins integrin ß4 and laminin 332, were increased. Surface modification to PEEK was suggested to enhance cell activity on PEEK.

Evaluation of the anti-androgenic and cytotoxic effects of benzophenone-3 in male Sprague-Dawley rats.

Benzophenone-3 (BP-3, 2-hydroxy-4-methoxybenzophenone, oxybenzone) is one of the most widely used types of benzophenone organic sunscreen. However, this compound is a potentially harmful toxicant. The aim of this study was 2-fold to: (1) utilize a Hershberger bioassay in vivo in castrated male Sprague-Dawley rats to investigate the anti-androgenic activities of BP-3, and (2) use in vitro a methyl tetrazolium assay to compare the toxicity between Leydig cells (TM3 cells) and mouse fibroblast (NIH-3T3) cell lines. In the Hershberger assay, rats were divided into 6 groups (each of n = 7): a vehicle control, negative control, positive control, PB-3 low (40 mg/kg), BP-3 intermediate (200 mg/kg), and BP-3 high (1000 mg/kg)-dose. The weight of the ventral prostate was significantly decreased at BP-3 doses of 200 or 1,000 mg/kg/day. In addition, the levator anibulbocavernosus muscle weights were also significantly reduced at BP-3 doses of 40, 200, or 1,000 mg/kg/day. In the MTT assay, the viability of NIH-3T3 mouse fibroblast cells was within the normal range. However, the TM3 mouse testis Leydig cell viability was significantly lowered in a concentration-dependent manner. Therefore, data indicate that BP-3 might exert in vivo anti-androgenic and in vitro cytotoxic effects in cells associated with the male reproductive system compared to normal non-reproductive cells.Abbreviation: BP-3: benzophenone-3; CG: Cowper's gland; DMEM: Dulbecco's modified Eagle's medium; DMSO: dimethyl sulfoxide; GP: glans penis; LABC: levator anibulbocavernosus muscle; MTT: methyl tetrazolium; NC: negative control; PC: positive control; SV: seminal vesicle; TP: testosterone propionate; VC: vehicle control; VP: ventral prostate.