Talar and fibular histiocytic-driven massive expansile osteolysis following polyetheretherketone interference screw implantation: a case report.

Numerous interference screws of different compositions exist including titanium screws, bioabsorbable screws, and polyetheretherketone (PEEK) screws. PEEK-based implants are frequently used in orthopaedic surgery due to their biocompatibility, similar elastic modulus to cortical bone, and purported negligible risk of osteolysis compared with bioabsorbable screws. In this case report, we present the case of a 48-year-old healthy female who experienced a massive osteolytic reaction in the talus and fibula after 11 weeks following implantation of PEEK-based interference screws during lateral ankle ligament reconstruction. The patient subsequently underwent removal of the PEEK screws and specimens were sent for microbiological and histopathological analysis. The specimens report demonstrated fibrotic tenosynovial soft tissue with patchy chronic inflammation, oedematous reactive changes, and histiocytic reaction, with no evidence of any significant acute inflammation. The patient recovered well and was asymptomatic at 6 months postoperatively. To our knowledge, this is the first case report of a massive osteolytic reaction to PEEK-based interference screws.

Optimal Changes Seen in Patients After Treatment With Poly- l -Lactic Acid: A Retrospective Descriptive Study.

BACKGROUND: Poly- l -lactic acid (PLLA) is a biostimulator that enhances collagen production and leads to volume restoration. It became popular because of its improvement of facial wrinkles and long-lasting effect, although the specific visible changes it causes in the facial area are not fully described. OBJECTIVE: To identify and characterize the visible changes resulting from injecting PLLA into the facial area. METHODS: A list of 678 patients who underwent 2 to 3 treatments with PLLA injections in this center between 2021 and 2022 were retrieved. After 2 rounds of evaluations, 31 independent international evaluators described the 3 main changes they observed in the before-and-after images (taken approximately 7 months after the last injection session) of the 12 patients with the most significant improvement. RESULTS: A total of 1,015 descriptions were received. They were divided into categories based upon similarity. The main detected changes were better contouring and enhancement of the lateral face, a lifting effect and secondary impact on the nasolabial fold, and improvement of skin texture and skin firmness. CONCLUSION: Poly- l -lactic acid injections were judged to be effective for contouring, lifting, and improving skin texture in the facial area. Further research is needed to validate these results and create an assessment scale for PLLA injections.

Development of metformin HCl granules using brown flaxseed mucilage as a retardant polymer: effects of polymer and drug ratio

Abstract Flaxseed (Linum usitatissimum L.) is the seed of a multipurpose plant of pharmaceutical interest, as its mucilage can be used as a natural matrix to develop extended-release dosage forms and potentially replace synthetic polymers. In this study, a 3² factorial design with two replicates of the central point was applied to optimize the development of extended-release granules of metformin HCl. The total fiber content of the mucilage as well as the friability and dissolution of the formulations were evaluated. The lyophilized mucilage presented a high total fiber content (42.63%), which suggests a high efficiency extraction process. Higher concentrations of the mucilage and metformin HCl yielded less friable granules. In addition, lower concentrations of metformin HCl and higher concentrations of the mucilage resulted in slower drug release during the dissolution assays. The release kinetics for most formulations were better represented by the Hixson-Crowell model, while formulations containing a higher concentration of the mucilage were represented by the Korsmeyer-Peppas model. Nonetheless, five formulations showed a longer release than the reference HPMC formulation. More desirable results were obtained with a higher concentration of the mucilage (13-18%) and a lower concentration of metformin (40%).

Comparison of biodegradable and durable polymer drug-eluting stents in acute coronary syndrome: a meta-analysis.

OBJECTIVE: To compare the safety and effectiveness between biodegradable polymer drug-eluting stents (BP-DES) and durable polymer drug-eluting stents (DP-DES) in patients with acute coronary syndrome (ACS). DESIGN: Meta-analysis of randomised controlled trials (RCTs). PRIMARY AND SECONDARY OUTCOME MEASURES: Major adverse cardiovascular events (MACEs) were considered the primary endpoint. Efficacy endpoints included target vessel revascularisation (TVR) and target lesion revascularisation (TLR). Safety endpoints included all-cause death, cardiac death, target vessel myocardial infarction and stent thrombosis (ST). METHODS: We searched PubMed, Medline, Embase and the Cochrane Controlled Register of Trials for comparative studies of BP-DES and DP-DES in patients with ACS from January 2000 to July 2021. Statistical pooling was performed to estimate incidence using a random-effects model with generic inverse-variance weighting. Risk estimates were computed with 95% CIs. RESULTS: Eight articles with seven RCTs that compared BP-DES and DP-DES in patients with ACS were identified and included in the qualitative and quantitative analyses. There was no difference in the baseline characteristics, except for the number of smoking patients (OR: 1.13, 95% CI 1.03 to 1.24; p=0.008, I2=29%), which was significantly lower in the BP-DES group. The meta-analysis demonstrated that MACEs, efficacy endpoints and safety endpoints were similar between the groups at 1 year. However, the incidence of total ST was significantly different between the BP-DES and DP-DES groups in the follow-up period (p=0.0001). Further analysis showed a statistically significant difference in MACEs (OR: 0.71, 95% CI 0.57 to 0.88; p=0.002, I2=0 %), TLR (OR: 0.71, 95% CI 0.51 to 1.01; p=0.05, I2=0%), TVR (OR: 0.70, 95% CI 0.52 to 0.94; p=0.002, I2=15%), total ST incidence (OR: 0.59, 95% CI 0.46 to 0.77; p=0.0001, I2=48%) and ST incidence (OR: 0.63, 95% CI 0.47 to 0.85; p=0.002, I2=0%) over 2 years. CONCLUSION: This meta-analysis revealed that both stent types demonstrated excellent safety and efficacy profiles at 12 months. However, a slight increase in MACEs, TLR, TVR and ST incidence was observed in the DP-DES group over the 2-year follow-up period, suggesting that BP-DES may be more favourable when treating patients with ACS. TRIAL REGISTRATION NUMBER: NCT00389220.

Toxicity risks of occupational exposure in 3D printing and bioprinting industries: A systematic review.

3-Dimensional (3D) printing and bioprinting are the new technologies. In 3D printing, synthetic polymers such as acrylonitrile, butadiene, and styrene, polylactic acid, nylon, and some metals are used as feedstocks. During 3D printing, volatile organic compounds (VOCs) and nanoparticles can be released. In the bioprinting process, natural polymers are most commonly used. All of these materials have direct and indirect toxic effects in exposed people. Therefore, the aim of this study was to provide a comprehensive review of toxicity risks due to occupational exposure to pollutants in the 3D printing and bioprinting industries. The Cochrane review method was used as a guideline for systematic review. Articles were searched in the databases including PubMed, Scopus, Web of Science, and Google Scholar. This systematic review showed that VOCs and ultra-fine particles are often released in fused deposition modeling and selective laser sintering, respectively. Asthma, chronic obstructive pulmonary disease, allergic rhinitis, and DNA damage were observed in occupational exposure to synthetic polymers. Metal nanoparticles can induce adverse health effects on the respiratory and nervous systems. This study emphasized the need to further study the toxicity of 3D printing and bioprinting-induced air pollutants. Also, consideration of safety and health principles is necessary in 3D printing and bioprinting workplaces.

Medical treatment of polymeric cerebral granulomatous reactions following endovascular procedures.

BACKGROUND: Endovascular procedures are standard of care for an increasing range of cerebrovascular diseases. Many endovascular devices contain plastic and are coated with a hydrophilic polymer which has been rarely described to embolize, resulting in distal granulomatous inflammatory lesions within the vascular territory. METHODS: We reviewed three cases of cerebral granulomatous reactions that occurred after endovascular intervention for internal carotid aneurysms. The patient procedure details, presentation, relevant investigations, and treatment course are described. We also provide a literature review on endovascular granulomatous reactions. RESULTS: These three cases represent the largest biopsy proven series of cerebral granulomatosis following endovascular intervention. We highlight the variable clinical presentation, with two of the three cases having an unusually delayed onset of up to 4 years following the intervention. We show the characteristic histological findings of granulomatous lesions with foreign body material consistent with a type IV reaction, radiological abnormalities of enhancing lesions within the vascular territory of the intervention, and the requirement of prolonged immunosuppression for maintenance of clinical remission, with two of the three patients requiring a corticosteroid sparing agent. In comparison with the available literature, in addition to hydrophilic gel polymer, we discuss that plastic from the lining of the envoy catheter may be a source of embolic material. We also discuss the recommendations of the Food and Drug Administration and the implementation of novel biomaterials for the prevention of these reactions in the future. CONCLUSIONS: There is a need for increased awareness of this severe complication of cerebral endovascular procedures and further longitudinal studies of its prevalence, optimal management and preventative measures.

Cutaneous Polymer-Coating Embolism After Endovascular Procedures: Report of Two Cases and a Literature Review.

ABSTRACT: Different hydrophilic and hydrophobic polymers are used as lubricious coatings to reduce vascular traumas in minimally invasive percutaneous procedures. Although they are usually very safe, there is still a risk of serious complications in patients undergoing such procedures, mostly derived from the devices' coating detachment and systemic embolization. The lungs are the most common organ involved, followed by the central nervous system. Yet, cutaneous embolization is unusual, and only 19 cases are available in the literature. Most commonly, they present as asymptomatic retiform purpura on the lower legs, which tends to involve spontaneously. Correct clinical diagnosis is not suspected in most cases, being cholesterol emboly or vasculitis the preferred options. Time interval since surgical procedure and appearance of lesions vary widely but they generally start in the first few days. Histopathological identification of the embolus as bluish, amorphous intraluminal material in dermal vessels is diagnostic, but vasculitic signs are not present. We report 2 cases of skin lesions as the main manifestation of polymer embolization after endovascular surgical procedures. In both cases, biopsy allowed identification of embolized foreign material and lesions resolved without specific treatment.

Foreign body reaction toward hydrophilic polymer at the site of endovascular procedure: A report of two cases.

Hydrophilic polymer-coated devices have been increasingly utilized for various endovascular procedures, however not been without adverse effects. We report two cases of subacute cutaneous lesions on the neck encountered in our dermatology clinic. Histopathologic findings were significant for a nodular aggregate of epithelioid histiocytes and lymphocytes with numerous foreign body giant cells in the dermis. The granulomatous infiltrate was associated with an amorphous basophilic non-polarizable material. Further chart review reveals both patients receiving a central venous procedure in the past, thus attributing the hydrophilic polymers as the likely source of the foreign material found at the insertion site. Our cases contrast to the more commonly reported distal embolization by these hydrophilic polymer layers. We suspect the incidence of retained hydrophilic polymer at the site of prior endovascular procedures may be underreported in the literature with the more inconspicuous presentations. Therefore, retained foreign material should be considered by both treating physicians and dermatopathologists in presenting cases of lesions that occur at common sites of endovascular procedures.

Carbon-fiber reinforced PEEK instrumentation for spondylodiscitis: a single center experience on safety and efficacy.

Radiolucent carbon-fiber-reinforced (CFR) polyethyl-ether-ether-ketone (PEEK) has been established in spinal instrumentation for oncological reasons. Laboratory data reported comparable bacterial adhesion as titanium. Thus, using of CFR-PEEK spinal instrumentation for spondylodiscitis bases on artifact-free imaging to evaluate therapeutic success. Studies comparing the rate of pedicle screw loosening and relapse of spondylodiscitis following titanium versus CFR-PEEK instrumentation do not exist so far. This study evaluates the rate of pedicle screw loosening and recurrence of spondylodiscitis after CFR-PEEK instrumentation for spondylodiscitis compared to titanium. We conducted a prospective single center study between June 2018 and March 2019 on consecutive 23 patients with thoracolumbar spondylodiscitis. Imaging data was evaluated for screw loosening at a minimum of three months after surgery. A matched-pair analysis was performed using spondylodiscitis cases between 2014 and 2016 using titanium instrumentation for equal localization, surgery, and microorganism class. Among 17 cases with follow-up imaging, six cases (35%) showed screw loosening while only 14% (two patients) with titanium instrumentation were loosened (p = 0.004). In both groups the most frequent bacterium was Staphylococcus aureus, followed by Staphylococcus epidermidis. From the S. aureus cases, one infection in both groups was caused by methicillin resistant species (MRSA). No difference was found in the rate of 360° fusion in either group due to matching criteria. As opposed to other indications CFR-PEEK screws show more loosening than titanium in this series with two potentially underlying reasons: a probably stronger bacterial adhesion on CFR-PEEK in vivo as shown by a statistical trend in vitro and instrumentation of spondylytic vertebrae. Until these factors are validated, we advise caution when implanting CFR-PEEK screws in infectious cases.

Behaviour of Vascular Smooth Muscle Cells on Amine Plasma-Coated Materials with Various Chemical Structures and Morphologies.

Amine-coated biodegradable materials based on synthetic polymers have a great potential for tissue remodeling and regeneration because of their excellent processability and bioactivity. In the present study, we have investigated the influence of various chemical compositions of amine plasma polymer (PP) coatings and the influence of the substrate morphology, represented by polystyrene culture dishes and polycaprolactone nanofibers (PCL NFs), on the behavior of vascular smooth muscle cells (VSMCs). Although all amine-PP coatings improved the initial adhesion of VSMCs, 7-day long cultivation revealed a clear preference for the coating containing about 15 at.% of nitrogen (CPA-33). The CPA-33 coating demonstrated the ideal combination of good water stability, a sufficient amine group content, and favorable surface wettability and morphology. The nanostructured morphology of amine-PP-coated PCL NFs successfully slowed the proliferation rate of VSMCs, which is essential in preventing restenosis of vascular replacements in vivo. At the same time, CPA-33-coated PCL NFs supported the continuous proliferation of VSMCs during 7-day long cultivation, with no significant increase in cytokine secretion by RAW 264.7 macrophages. The CPA-33 coating deposited on biodegradable PCL NFs therefore seems to be a promising material for manufacturing small-diameter vascular grafts, which are still lacking on the current market.

Vaping cartridge heating element compositions and evidence of high temperatures.

BACKGROUND: Identifying the functional materials inside vaping devices can help inform efforts to understand risk. While nicotine E-cigarette components and metals have been characterized in several previous studies, the internal component compositions of tetrahydrocannabinol (THC) cartridge designs are not as well known. The 2019-20 e-cigarette or vaping product use associated lung injury (EVALI) outbreak has been associated with THC devices containing vitamin E acetate (VEA), possibly mediated by chemical reactions with internal cartridge components and high filament temperatures. METHODS: We investigate the composition and internal components of 2019 EVALI patient-associated THC vaping devices compared to other THC and nicotine devices from 2016-19, specifically the metal, ceramic, and polymer components likely to be exposed to heat. To do this, we have disassembled forty-eight components from eight used and unused vaping devices under a microscope and analyzed them using X-ray fluorescence, scanning electron microscopy, and Fourier-transform infrared micro-spectroscopy. CONCLUSIONS: The two THC cartridges used by EVALI patients exhibited evidence of localized high temperatures, including charring of the ceramic heating elements and damaged wire surfaces. The newer THC cartridges possessed more ceramic and polymer insulation than older THC or nicotine devices. The combination of ceramics, metals, and high temperatures in newer THC cartridges is consistent with conditions hypothesized to produce VEA reactions during vaping. Nickel and chromium components were detected in all devices, and others contained copper, lead, tin, gold, silicon-rich rubbers, or fluorinated microplastics. These components have the potential to thermally degrade and volatilize if heated sufficiently. These findings do not imply that harmful exposures would occur under all usage conditions, and are most relevant to harm reduction efforts based on avoiding higher internal temperatures. This study was limited to a small sample of cartridges obtained from investigations. Future work should test more device types and internal temperatures under controlled usage conditions.

Nanoparticles' properties modify cell type-dependent distribution in immune cells.

Polymeric nanoparticles can passively target inflamed tissues. How their physicochemical properties affect their distribution pattern among the infiltrating immune cells is unknown. Polyvinyl acetate nanoparticles with different particle size (100 and 300 nm) and surface charge (cationic, non-ionic, and anionic) were prepared and incubated with either LPS-activated or unactivated murine splenocytes. Nanoparticle association with macrophages, dendritic cells, neutrophils, B and T cells was investigated using flow cytometry. Cells associated with nanoparticles as follows: cationic>anionic>non-ionic and 300 nm > 100 nm. 40% of ionic nanoparticles were distributed among unactivated macrophages, reduced to 25% for activated macrophages. 60% of 100 nm and 40% of 300 nm non-ionic nanoparticles were distributed among unactivated and LPS-activated macrophages. This study highlights that particles' physicochemical properties impact the number of nanoparticles associating with immune cells more than their distribution pattern, which is principally determined by the cell activation state. This suggests a disease-dependent distribution pattern for therapeutic nanoparticles.

Features of endoscopic procedure site reaction associated with a recently approved submucosal lifting agent.

Endoscopic resection techniques, such as endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD), are frequently aided by injection of submucosal lifting solutions that create a plane for dissection and protect deeper mural layers. ORISE™ gel is a recently approved synthetic lifting solution that produces a localized inflammatory reaction associated with retained gel at the injection site. We describe a series of six cases of ORISE™-associated inflammatory lesions in patients who underwent endoscopic resections. Deposits comprised pale fibrillary or hyalinized eosinophilic material, depending on their age. All cases were associated with an inflammatory reaction composed of foreign-body giant cells and scattered eosinophils. ORISE™ gel extended laterally and deeply beyond residual tumors in all cases. Histochemically, the material proved to be negative for Congo Red, and mucicarmine, faint blue with Alcian blue, but positive for PAS and PAS-D. It stained blue with trichrome. Such deposits were absent in cases, wherein other widely-available lifting solutions were used. We compared ORISE™ deposits to histologically similar extracellular deposits, namely amyloid and pulse granulomata. Unlike ORISE™ material, amyloid deposits appear as waxy, more densely eosinophilic material, and stain positive with Congo Red. Amyloid demonstrated prominent intramucosal and perivascular distributions, features not seen in this series of ORISE™ deposits. Hyalinized pulse granulomata showed strong overlap with ORISE™ deposits, since they also comprise eosinophilic material associated with giant cell reaction. On the other hand, they form ribbons of glassy material in circumscribed lobules, unlike the ill-defined ORISE™ deposits. In summary, we describe the pathologic findings at injection sites in patients who underwent endoscopic procedures aided by the recently approved lifting agent, ORISE™. Pathologists should be aware of its appearance and associated reaction to avoid confusion with other common extracellular deposits seen in the gastrointestinal tract.

A randomized controlled trial investigating the effect of a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols on the intestinal microbiome and inflammation in patients with ulcerative colitis: study protocol for a randomized controlled trial.

BACKGROUND: No conclusive treatment is available for irritable bowel disease (IBD). Adherence to a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) might alleviate clinical symptoms of IBD. However, no study has investigated the effect of low FODMAPs diet on the intestinal microbiota and inflammatory biomarkers in patients with IBD. The aim of current study is to examine the effect a low FODMAP diet on IBD symptoms, inflammation, and the intestinal microbiota in patients with ulcerative colitis. METHODS AND ANALYSIS: This study is a randomized clinical trial. Thirty patients with mild to moderate ulcerative colitis will be randomly allocated to receive a low FODMAP diet (n = 15) or to continue their usual diet as control (n = 15), for 4 weeks. The quantity of intestinal microbiota including Clostridium cluster IV, Faecalibacterium prausnitzii, Rosburia spp., Lactobacillus spp., Bifidobacteria spp., Akkermansia muciniphila, Bacteroides fragilis, and Ruminococcus spp., and the Firmicutes to Bacteroidetes ratio and calprotectin and lactoferrin levels will be explored in fecal samples from patients. In addition, anthropometric measures and biochemical assessments including serum concentrations of highly sensitive-C reactive protein (hs-CRP), tumour necrosis factor-α (TNF-α) and IL-1ß will be taken from patients at baseline and end of the study. The study has been registered in IRCT (IRCT20181126041763N1; registration date: 2019-01-18). DISCUSSION: Consumption of a low-FODMAP diet might decrease systemic and intestinal inflammation, change the bacterial population in the gut, and modulate clinical symptoms in patients with ulcerative colitis. Further studies investigating the effect of such a diet on other variables, including other bacterial species and inflammatory cytokines, are required to confirm future findings of this trial.

Postmarket Experience of Polymethylmethacrylate-Collagen Gel Dermal Filler.

BACKGROUND: This report synthesizes 12 years of postmarket surveillance data (PMSD) for polymethylmethacrylate (PMMA)-collagen gel dermal filler. OBJECTIVE: To present PMMA-collagen gel PMSD findings on real-world safety. METHODS: Postmarket surveillance data were collected from January 2007 to December 2018 and evaluated to determine the overall adverse event (AE) complaint rate, the nature of reported AEs, and whether the complaint included on-label, off-label, both, or unknown areas. RESULTS: In the 12 years examined, 754,229 PMMA-collagen gel syringes were distributed worldwide, and 839 product-related complaints (including those classified as unknown) resulted in an overall complaint rate of 0.11%. The 3 most frequent primary complaints in AE reports were lump/bump (309/839, 37%), nodule (152/839, 18%), and swelling (138/839, 16%). Histologically confirmed granuloma accounted for 17/839 complaints (2.0%; overall complaint rate of 0.002%), and histologically unconfirmed granuloma accounted for 66/839 complaints (8%; overall rate of 0.009%). There were 666 complaints representing AEs related to off-label injection in which the periocular area was most frequently represented. CONCLUSION: Although a limiting factor across all PMSD is voluntary reporting and resultant underrepresentation of AEs, the PMSD reported here are consistent with safety findings from US clinical studies in more than 1,500 patients with up to 5 years of follow-up.

Size-Dependent in Vitro Biocompatibility and Uptake Process of Polymeric Carbon Nitride.

Polymeric carbon nitride (PCN), which demonstrates unique properties, has been widely explored, mostly in photocatalysis; however, the evaluation of its biocompatibility is still needed. Herein, the cytocompatibility of PCN with different lateral size distributions (A-PCN with 160 nm, B-PCN with 20 nm, and C-PCN with 10 nm dominating lateral sizes) was investigated. The viability of three cell lines (L929, MCF-7, and HepG2) has been determined using cell counting kit-8 (CCK-8), neutral red uptake (NRU), and lactate dehydrogenase (LDH) leakage assays. It was found that the highest cytotoxicity of PCN was observed for flakes with a lateral size of ∼20 nm (B-PCN) in three cell lines after 48 h of exposition. The uptake process of B-PCN sheets labeled with fluorescein isothiocyanate (FITC) by cells was also the most effective. Confocal laser scanning microscopy and atomic force microscopy revealed the nanomaterial distribution throughout the cytoplasm and perinuclear region. The results demonstrated the correlation among size, internalization process, and cytocompatibility of the tested polymeric carbon nitride structures.