The characteristics of dopamine self-polymerization were used to cover the nano-titanium dioxide (TiO2) surface and produce nano-titanium dioxide-polydopamine (TiO2-PDA). The reducing nature of dopamine was then used to reduce silver nitrate to silver elemental particles on the modified nano-titanium dioxide: The resulting TiO2-PDA-Ag nanoparticles were used as antimicrobial agents. Finally, the antibacterial agent was mixed with silicone to obtain an antibacterial silicone composite material. The composition and structure of antibacterial agents were analyzed by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron energy spectroscopy, and X-ray diffraction. Microscopy and the antibacterial properties of the silicone antibacterial composites were studied as well. The TiO2-PDA-Ag antimicrobial agent had good dispersion versus nano-TiO2. The three were strongly combined with obvious characteristic peaks. The antibacterial agents were evenly dispersed in silicone, and the silicone composite has excellent antibacterial properties. Bacillus subtilis (B. subtilis) adhesion was reduced from 246 × 104 cfu/cm2 to 2 × 104 cfu/cm2, and colibacillus (E. coli) reduced from 228 × 104 cfu/cm2 leading to bacteria-free adhesion.

Endoscopic approach with recanalization and stenting is one of the methods for cicatricial tracheal stenosis. Major complications may occur if service life of stents is not observed. However, there are currently no clear timing for stenting. In world practice, there are no indications on lifelong stenting for cicatricial tracheal stenosis. Restenosis is more common after stent removal and requires repeated stenting or another treatment. In case of prolonged stenting, silicone stent should be periodically replaced with a similar one due to destruction of silicone rubber. As a rule, this maneuver is necessary after 1-3 years. Currently, there is no information about maximum allowable duration of stent without replacement and possible complications. Condition of trachea after prolonged stenting is also unknown. We present long-term (27 years) tracheal stenting with a silicone stent. Stent fragmentation and dislocation throughout this period led to respiratory failure and emergency removal. Tracheal lumen was satisfactory immediately after procedure. However, restenosis appeared after 1.5 months and required endoscopic dilation with discussion of appropriate treatment option. However, the patient refused tracheal resection with anastomosis and underwent repeated stenting with similar stent and favorable immediate result.
При лечении рубцового стеноза трахеи одним из методов его коррекции является эндоскопический, заключающийся в реканализации и стентировании суженного сегмента трахеи. При несоблюдении сроков эксплуатации стентов возможно возникновение угрожающих осложнений. Однако в настоящее время нет строго определенных сроков стентирования. В мировой практике отсутствуют указания на возможность пожизненного применения данного варианта лечения рубцового стеноза трахеи. Чаще после удаления стента возникает рестеноз, что вынуждает выполнять рестентирование или избирать другое лечение. При необходимости пролонгирования стентирования силиконовый стент приходится периодически менять на аналогичный из-за разрушения силиконовой резины. Как правило, потребность в этом возникает через 1—3 года. В настоящее время нет сведений о максимально допустимом сроке нахождения стента без его замены, а также о возможных при этом осложнениях. Неизвестно и состояние трахеи после длительного эндопротезирования. Приведено наблюдение продолжительного (27 лет) стентирования трахеи силиконовым стентом. В течение этого периода стент фрагментировался, дислоцировался, что привело к нарушению дыхания и потребовало его экстренного удаления. Непосредственно после этого просвет трахеи оставался удовлетворительным. Через 1,5 мес возник рестеноз, что стало показанием к эндоскопическому бужированию и обсуждению изменения варианта лечения. Однако от радикальной резекции трахеи с анастомозом больная отказалась, и ей выполнили рестентирование аналогичным стентом с хорошим непосредственным результатом.

UNASSIGNED: Managing the gap between the dressing and the wound bed can facilitate the healing of exuding wounds. A silicone foam dressing (Biatain Silicone; Coloplast A/S, Denmark) was developed for application to exuding wounds. A sub-analysis of the real-world, prospective, observational VIPES (Observatoire en Ville des Plaies ExSudatives) study was conducted to investigate the use and performance of the silicone foam dressing in a community nursing setting in France.
UNASSIGNED: The sub-analysis included patients from the VIPES study who received the silicone foam dressing as a primary dressing for an acute or hard-to-heal (chronic) wound. Epidemiological and wound healing outcomes were reported via a smartphone application.
UNASSIGNED: Overall, 64 patients were included in the sub-analysis. At baseline, most wounds (n=33/40; 82.5%) were in treatment failure (i.e., were stagnant, non-healing or had poor exudate management). At the last follow-up visit, a median of 22.5 (range: 3-151) days post baseline, 48.4% of wounds had healed and 25.0% were progressing towards healing. From baseline to the last follow-up visit, significant reductions in exudate level (p<0.0001) and exudate pooling (p<0.0001), and significant improvements in wound edges (p≤0.0001) and periwound skin (p<0.01) were observed. A total of 62.3% of patients had re-epithelialising wounds at the last follow-up visit. The majority of nurses (88.3%) and patients (85.0%) reported that the wound had improved and, at most dressing removals (93.5%), nurses reported that the dressing conformed closely to the wound bed.
UNASSIGNED: Overall, the data suggest that use of the silicone foam dressing in community practice supported the healing of wounds, illustrating the importance of exudate and gap management.

Liquid-infused polymers are recognized for their ability to repel foulants, making them promising for biomedical applications including catheter-associated urinary tract infections (CAUTIs). However, the impact of the quantity of free liquid layer covering the surface on protein and bacterial adhesion is not well understood. Here, we explore how the amount of free silicone liquid layer in infused silicone catheter materials influences the adhesion of bacteria and proteins relevant to CAUTIs. To alter the quantity of the free liquid layer, we either physically removed excess liquid from fully infused catheter materials or partially infused them. We then evaluated the impact on bacterial and host protein adhesion. Physical removal of the free liquid layer from the fully infused samples reduced the height of the liquid layer from 60 μm to below detection limits and silicone liquid loss into the environment by approximately 64% compared to controls, without significantly increasing the deposition of protein fibrinogen or the adhesion of the common uropathogen Enterococcus faecalis. Partially infused samples showed even greater reductions in liquid loss: samples infused to 70%-80% of their maximum capacity exhibited about an 85% decrease in liquid loss compared to fully infused controls. Notably, samples with more than 70% infusion did not show significant increases in fibrinogen or E. faecalis adhesion. These findings suggest that adjusting the levels of the free liquid layer in infused polymers can influence protein and bacterial adhesion on their surfaces. Moreover, removing the free liquid layer can effectively reduce liquid loss from these polymers while maintaining their functionality.

BACKGROUND: A straight silicone stent can be used to treat proximal benign tracheal stenosis in non-surgical candidates. However, stent migration is a common complication when placed at a particular location and can lead to major complications. This case series of laryngotracheal stenosis reports a fixation method for straight silicone stents in the subglottic trachea (Stage 3 of the McCaffrey classification).
METHODS: The medical charts of these patients scheduled for straight silicone stent placement with suture fixation between 2014 and 2020 at the CHU UCL Namur Hospital (Belgium) were retrospectively reviewed. The procedure was performed using a rigid bronchoscope. Details of the procedure were obtained from medical records.
RESULTS: This case series included six patients (males: 4, females: 2). The median patient age was 59 years. Two suture fixations were placed following previous silicone stent migration episodes, whereas the others were placed proactively to avoid this risk. All fixations were performed by the device Freka® Pexact II ENFIt®, originally developed for gastropexy in endoscopic gastrostomy. The sutures were subcutaneously buried.
CONCLUSIONS: During the 6-month follow-up period, complications such as fixation issues and stent migration were reported despite the off-label use of the treatment. The straight silicone stent fixation technique used in this case series was simple and effective for securing the stent in upper benign tracheal stenosis.

BACKGROUND: The elastomechanical properties of nanocarriers have recently been discussed as important for the efficient delivery of various therapeutics. Some data indicate that optimal nanocarriers\' elasticity can modulate in vivo nanocarrier stability, interaction with phagocytes, and uptake by target cells. Here, we presented a study to extensively analyze the in vivo behavior of LIP-SS liposomes that were modified by forming the silicone network within the lipid bilayers to improve their elastomechanical properties. We verified liposome pharmacokinetic profiles and biodistribution, including retention in tumors on a mouse model of breast cancer, while biocompatibility was analyzed on healthy mice.
RESULTS: We showed that fluorescently labeled LIP-SS and control LIP-CAT liposomes had similar pharmacokinetic profiles, biodistribution, and retention in tumors, indicating that modified elasticity did not improve nanocarrier in vivo performance. Interestingly, biocompatibility studies revealed no changes in blood morphology, liver, spleen, and kidney function but indicated prolonged activation of immune response manifesting in increased concentration of proinflammatory cytokines in sera of animals exposed to all tested liposomes.
CONCLUSIONS: Incorporating the silicone layer into the liposome structure did not change nanocarriers\' characteristics in vivo. Further modification of the LIP-SS surface, including decoration with hydrophilic stealth polymers, should be performed to improve their pharmacokinetics and retention in tumors significantly. Activation of the immune response by LIP-SS and LIP-CAT, resulting in elevated inflammatory cytokine production, requires detailed studies to elucidate its mechanism.

BACKGROUND: Incontinence-associated dermatitis (IAD) is a tough problem in clinical settings, not only increasing the risk of complications like catheter-related urinary tract infections and pressure ulcers in elderly and critically ill patients, but also prolonging hospital stays, raising hospital costs, and possibly leading to medical disputes. This study is aimed to evaluate the therapeutic effect of silicone dressing combined with topical oxygen therapy on IAD in a rat model.
METHODS: An IAD rat model induced by synthetic urine with trypsin was established. Hematoxylin & eosin staining was carried out to examine skin histology. Using immunofluorescence, the microvessel density in the affected skin tissues was determined. ELISA was performed to measure the concentrations of inflammatory cytokines and angiogenic factors in serum. The mRNA expression of EGF, PDGF, and VEGF was detected via qRT-PCR. Western blotting was employed to determine NF-κB p65/STAT1 pathway-related protein levels.
RESULTS: Compared to single therapy, silicone dressing combined with topical oxygen therapy could significantly reduce the severity of IAD, improve skin histology, inhibit inflammation, and promote angiogenesis in IAD rat models. Additionally, the results showed that relatively speaking, the combined therapy suppressed the NF-κB p65/STAT1 signaling pathway more effectively.
CONCLUSIONS: These findings indicated that silicone dressing combined with topical oxygen therapy can alleviate IAD through promoting wound healing and inhibiting inflammation via NF-κB p65/STAT1 signaling pathway in a rat model, which provided a theoretical basis for the prevention and treatment of IAD in clinic.

The biomedical applications of silicones are countless due to their outstanding properties. In dentistry, silicone for maxillofacial and plastic surgery has become indispensable, from both physiological and aesthetic points of view. In this mini-review, silicone materials for dentistry and facial prostheses are discussed, focusing on their properties and alterations when exposed for long periods to different environments. A significant number of studies reported in the literature have been conducted in vitro, mimicking some of the main degradative factors which have been identified as triggers for discoloration and deterioration of the mechanical properties. Among these, in artificial aging and accelerated natural aging studies, UV radiation is considered the most important. Other weathering factors, biological contamination, and disinfection agents may have dramatic effects as well. Several general properties of silicones are described at the beginning, with a focus on biocompatibility, cross-linking mechanisms, and applications in dentistry and maxillofacial prosthetics. We discuss the ongoing cross-linking and/or possible exudation after manufacturing, which also affects the stability of the prosthesis over time, and possibly the patient. Next, the main environmental factors that affect the prostheses in service are presented, including the role of cigarettes smoke, which has been discussed very little so far. A few aspects, such as biofilm formation, its negative effects, and proposed solutions to overcome this phenomenon regarding silicones, are also described. We conclude by proposing a set of topics for future research and development based on the gaps that have been identified in the literature. Although silicones are probably irreplaceable in maxillofacial prosthetics, improvements in terms of base materials, additives, surface treatments, and maintenance are possible and necessary for long-lasting and safer prostheses.

Objectives: Some small defects may remain in the impression after making a two-step putty-light body impression. The aim of this study was to evaluate and compare the dimensional accuracy of 2-step and relined 2-step (3-step) putty-light body impressions. Materials and Methods: In this in vitro study, 30 impressions were made with putty, light body, and extra-light body addition silicone materials using the 2-step and 3-step impression techniques (N=15). An epoxy resin master model was made duplicating a maxillary typodont with left first premolar and first molar teeth prepared with a shoulder finish line and truncated pyramidal-shaped indices in the mid-palate and third molar sites. In addition to creating a reference digital model by scanning the master model, 30 master casts were scanned to produce digital models. The anteroposterior (AP) and cross-sectional (CS) dimensional accuracy of the models were compared with the master model using linear measurements. Moreover, tooth size measurements were made and compared using the root mean square (RMS). Two-sample t-test was applied to analyze the data (α=0.05). Results: The mean AP and RMS differences between the two study groups were not significant (P>0.05). However, the CS difference between the two groups was significant (P<0.001), and the 3-step impression technique showed smaller discrepancies in comparison to the master model. Conclusion: There was no significant difference in accuracy of the two techniques for single-unit and multiple-unit preparations. The 3-step impression technique had a higher CS dimensional accuracy.

BACKGROUND: Airway stenting may be needed to manage anastomotic complications in lung transplant recipients. Conventional stenting strategies may be inadequate due to anatomic variations between the recipient and donor or involvement of both the anastomosis and lobar bronchi.
METHODS: We investigated the efficacy of 3D-designed patient-specific silicone Y-stents in managing this scenario. 9 patients with complex airway stenosis underwent custom stent insertion after either failing traditional management strategies or having anatomy not suitable for conventional stents. CT images were uploaded to stent design software to make a virtual stent model. 3D printing technology was then used to make a mold for the final silicone stent which was implanted via rigid bronchoscopy. Forced expiratory volume in 1 s (FEV1) was measured pre- and post-stent placement.
RESULTS: 78 % of patients experienced an increase in their FEV1 after stent insertion, (p = 0.001, 0.02 at 30 and 90 days respectively). Unplanned bronchoscopies primarily occurred due to mucous plugging. 2 patients had sufficient airway remodeling allowing for stent removal.
CONCLUSIONS: Personalized 3D-designed Y-stents demonstrate promising results for managing complicated airway stenosis, offering improved lung function and potential long-term benefits for lung transplant recipients.