Filler found in bone: Surgical removal of polyacrylamide hydrogel (Amazingel) from the mandible after 24 years: A case report and literature review.

Polyacrylamide hydrogel (PAAG) is widely regarded as a safe soft tissue filler and has been extensively utilized for cosmetic enhancements, such as breast and facial augmentation in China from 1997 until its ban in 2006. Common complications associated with its use include inflammation, infection, granulomas, fibrosis, gel migration, and facial and soft tissue deformities. This case report describes a 45-year-old Chinese woman who experienced PAAG migration into her mandible 24 years after facial augmentation, causing irritation of the mandibular alveolar nerve - apparently the first documented instance of this occurrence. Surgical intervention was necessary to remove the migrated gel and associated calcifications. A literature review explored adverse events and management strategies for PAAG complications in cosmetic procedures. While generally considered safe, this report underscores the importance of meticulous injection techniques and careful anatomical site selection to prevent such severe complications.

Granulomatous mastitis and pectoralis major muscle defect following polyacrylamide hydrogel injection: a case report and literature review.

Background: Breast augmentation through the injection of polyacrylamide hydrogel (PAAG) was a popular procedure in the past, but it has since been prohibited due to various complications, including masses, migration, infection, inflammation, and even cancer. However, there were rare cases of granulomatous mastitis with pectoralis major muscle defect following PAAG injection for breast augmentation. Case Description: A 40-year-old female patient presented with a swollen and suppurative mass in her left breast and was insensitive to antibiotics. She was admitted to our department for further treatment after 7 months with progressive local and general symptoms. Ultrasound imaging showed ill-defined heterogeneous echoes, and contrast-enhanced magnetic resonance imaging (MRI) revealed non-mass enhancement lesions in the multiregional distribution in Breast Imaging-Reporting and Data System 4A (BI-RADS 4A) with oedema in the retroglandular space and multiple enlarged lymph nodes in the ipsilateral axilla. Intraoperative observations revealed necrotic tissues, multiple abscesses, residual mucoid PAAG prosthesis diffused into the mammary glands and intramuscularly into the pectoralis muscle, and partial loss of pectoralis major muscle. Histopathological results revealed foreign-body granulomas accompanied by gel-like granular PAAG and proliferative inflammatory cells. She recovered after undergoing the characteristic surgical management in our center under general anesthesia and had no recurrence during the 2-year follow-up. Conclusions: This case revealed that PAAG injection for augmentation mammaplasty, even after the removal operation, could result in subsequent complications, including granulomatous mastitis and pectoralis major muscle damage. PAAG filler complications are difficult to treat, therefore, it is essential to establish appropriate and effective therapeutic procedures.

Synthesis and Characterisation of Hemihydrate Gypsum-Polyacrylamide Composite: A Novel Inorganic/Organic Cementitious Material.

This study combined inorganic α-hemihydrate gypsum (α-HHG) with organic polyacrylamide (PAM) hydrogel to create a novel α-HHG/PAM composite material. Through this facile composite strategy, this fabricated material exhibited a significantly longer initial setting time and higher mechanical strength compared to α-HHG. The effects of the addition amount and the concentration of PAM precursor solution on the flowability of the α-HHG/PAM composite material slurry, initial setting time, and mechanical properties of the hardened specimens were investigated. The structural characteristics of the composite material were examined using XRD, FE-SEM, and TGA. The results showed that the initial setting time of the α-HHG/PAM composite material was 25.7 min, which is an extension of 127.43% compared to that of α-HHG. The flexural strength and compressive strength of the oven-dried specimens were 23.4 MPa and 58.6 MPa, respectively, representing increases of 34.73% and 84.86% over values for α-HHG. The XRD, FE-SEM, and TGA results all indicated that the hydration of α-HHG in the composite material was incomplete. The incompleteness is caused by the competition between the hydration process of inorganic α-HHG and the gelation process of the acrylamide molecules for water, which hinders some α-HHG from entirely reacting with water. The enhanced mechanical strength of the α-HHG/PAM composite material results from the tight interweaving and integrating of organic and inorganic networks. This study provides a concise and efficient approach to the modification research of hemihydrate gypsum.

Development of the Antioxidant Property of Seagrass Extract-Based Hydrogel for Dental Application.

Background Seagrass is rich in antioxidants, which can help neutralize harmful free radicals in the oral cavity. Free radicals can contribute to oxidative stress, inflammation, and various oral health issues. Incorporating seagrass extract into a hydrogel can enhance its antioxidant capacity, providing a protective effect for oral tissues. The hydrogel, composed of a biocompatible base, ensures that the material is well-tolerated by oral tissue. This is crucial for any dental application to avoid adverse reactions. Aim This work aimed to develop an antioxidant hydrogel that incorporates seagrass extract, with a specific emphasis on its possible use in dentistry. Methods A seagrass sample was collected, and its bioactive compounds were extracted through the utilization of methanol, and subsequent filtration was done. The resulting seagrass filtrate was then integrated into a hydrogel, which was synthesized using polyacrylamide and sodium alginate. Antioxidant hydrogel underwent testing for antioxidant activity through both the 2,2-diphenyl-1-picrylhydrazyl assay and the 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) assay. Besides, the hydrogel functional groups were investigated using Fourier transform infrared spectroscopy, while its crystalline structure was examined using X-ray diffraction analysis. Conclusion Seagrass extract provides inherent antioxidant properties, and incorporating this bioactive extract into the hydrogel imparts antioxidant features. The hydrogel's controlled-release property ensures both safety and efficiency. Antioxidant hydrogel for dental applications holds the potential to improve oral health.

Serial injections of 4% polyacrylamide hydrogel have no detrimental effects in equine joints following clinical, histologic, and synovial biomarker evaluation.

OBJECTIVE: Polyacrylamide hydrogel (4% PAHG) is an inert viscoelastic supplement used to manage osteoarthritis in horses. Even with a prolonged clinical effect, horses may be administered multiple doses during their performance career. The effect of the serial 4% PAHG treatments is not known. The objectives of this study were to evaluate the clinical, histologic, and synovial fluid biomarker effects following serial administration of 4% PAHG in normal equine fetlock joints. ANIMALS: 8 healthy horses. METHODS: In a blinded, controlled in vivo study, horses received serial intra-articular injections of 4% PAHG (Noltrex Vet; Nucleus ProVets LLC) and contralateral 0.9% saline control on days 0, 45, 90, and 135. Treatment and control joints were randomly assigned. Synovial fluid was collected before administration of 4% PAHG or 0.9% saline on day 0 and at study completion for cellular and biomarker evaluation. Serial physical and lameness examinations were performed throughout the study. On day 240, gross examination and harvest of cartilage and synovial membrane for histology were completed. RESULTS: There were no histologic changes in articular cartilage or synovial fluid biomarkers. The 4% PAHG was seen on the surface of the synovium in 5 of 8 treated joints 105 days after the last treatment. There are minimal effects following serial injections of 4% PAHG on normal joints in horses following administration at 0, 45, 90, and 135 days, with final evaluation on day 240. CLINICAL RELEVANCE: Serial administration of intra-articular 4% PAHG in horses may provide long-term joint lubrication with no detrimental effects.

Photosensitive Hydrogel with Temperature-Controlled Reversible Nano-Apertures for Single-Cell Protein Analysis.

Single cell western blot (scWB) is one of the most important methods for cellular heterogeneity profiling. However, current scWB based on conventional photoactive polyacrylamide hydrogel material suffers from the tradeoff between in-gel probing and separation resolution. Here, a highly sensitive temperature-controlled single-cell western blotting (tc-scWB) method is introduced, which is based on a thermo/photo-dualistic-sensitive polyacrylamide hydrogel, namely acrylic acid-functionalized graphene oxide (AFGO) assisted, N-isopropylacrylamide modified polyacrylamide (ANP) hydrogel. The ANP hydrogel is contracted at high-temperature to constrain protein band diffusion during microchip electrophoretic separation, while the gel aperture is expanded under low-temperature for better antibody penetration into the hydrogel. The tc-scWB method enables the separation and profiling of small-molecule-weight proteins with highly crosslinked gel (12% T) in SDS-PAGE. The tc-scWB is demonstrated on three metabolic and ER stress-specific proteins (CHOP, MDH2 and FH) in four pancreatic cell subtypes, revealing the expression of key enzymes in the Krebs cycle is upregulated with enhanced ER stress. It is found that ER stress can regulate crucial enzyme (MDH2 and FH) activities of metabolic cascade in cancer cells, boosting aerobic respiration to attenuate the Warburg effect and promote cell apoptosis. The tc-scWB is a general toolbox for the analysis of low-abundance small-molecular functional proteins at the single-cell level.

Vulvar migration of injected polyacrylamide hydrogel following breast augmentation: a case report and literature review.

BACKGROUND: Vulvar migration is a rare complication of filler injection for breast augmentation, generally presenting as repeated pain and fever. We will report a case of woman with polyacrylamide hydrogel breast injection develops vulvar abscess. CASE PRESENTATION: A woman with a history of polyacrylamide hydrogel breast injection was noted to have vulvar abscess due to migration of filler materials. Filler removal surgery and vacuum sealing drainage was performed for this patient. The patient was discharged from the hospital with no further complications. After a review of pertinent literature, only four previous case reports are found. Local inflammatory response, infection, large volume injections, inframammary fold destruction, hematogenous or lymphatic migrate, trauma, gravity and external pressure could play essential parts in the migration of injected filler. CONCLUSION: Polyacrylamide hydrogel migration poses a worldwide challenge, necessitating personalized solutions. Our case study underscores the importance of comprehensive examinations for individuals with a history of filler breast injection when suspecting vulvar filler migration.

Optimized protocol for high-vacuum scanning electron microscopy analysis of polyacrylamide hydrogel-attached sperm cells in a binary system.

A protocol for the analysis of a binary system comprising polyacrylamide hydrogel-attached sperm cells using high-vacuum scanning electron microscopy (SEM) is presented. This protocol focuses on optimizing the SEM procedure to obtain accurate and detailed imaging of the sperm cells and their interactions with the hydrogel scaffold. The methodology involves a stepwise sample preparation, including sample dehydration through a gradual exchange of ethanol/water ratios, followed by the application of a conductive metal coating. By employing this modified protocol, the traditional use of acetone dehydration, which may introduce chemical alterations to the materials, is avoided. The proposed approach enables a comprehensive evaluation of the morphology and interactions within the biological system in contact with the soft material scaffold. Furthermore, the potential application of this protocol extends to the study of other mammalian reproductive cells or cells of different origins adhered to hydrogel scaffolds. RESEARCH HIGHLIGHTS: Novel SEM protocol reveals precise imaging of sperm-hydrogel attachment in a binary system, enhancing our understanding of cell-material interactions. By optimizing SEM procedures, the protocol achieves precise imaging of sperm-hydrogel interactions using ethanol/water dehydration and a conductive metal coating. This modified approach enables a thorough assessment of morphology and interactions in the binary system,extending its potential applicability to other reproductive cells on hydrogelscaffolds.

Application of magnetic resonance imaging with intraoperative color Doppler ultrasound in the treatment of patients with polyacrylamide hydrogel injected for breast augmentation: a retrospective study of 204 cases for 12 years.

Purpose: Polyacrylamide hydrogel (PAHG), which had been used widely for breast augmentation, has been banned for more than 15 years. Patients who had been injected PAHG for breast augmentation need evacuation surgery to remove as much as possible. To provide a series of diagnosis and treatment process MRI and intraoperative color Doppler ultrasound are combined for maximal removal of PAHG. Methods: The patients who received evacuation surgery in Peking University Third Hospital from 2010 to 2022 after PAHG injection for breast augmentation were included in this research. MR scanning was performed preoperatively and postoperatively in some of these patients and color Doppler ultrasound was applied to help evacuate PAHG intraoperatively. The mean clearance rate of PAHG was calculated according to the MRI outcomes. Results: Two hundred and 4 patients had received evacuation surgery after PAHG injection for breast augmentation with an average age of 42.8 years and an average body mass index of 21.2 kg/m2. The average PAHG retention time was 13.5 years. Among them, 52 patients underwent pre- and postoperative MRI scanning. The mean three-dimensional (3D) volume of PAHG was 684.8 mL (range, 350.0-1,123.9 mL), and the average residual 3D volume of PAHG was 53.7 mL (range, 12.4-98.3 mL). The mean clearance rate was 92.1%. Conclusion: MRI and intraoperative color Doppler ultrasound can provide effective and precise location information of PAHG for evacuation surgery, which is a reliable method to ensure the maximal removal of PAHG.

[Augmentation mammaplasty using injected polyacrylamide hydrogel: Report of a recent case and literature review]. / Mammoplastie d'augmentation par injection d'hydrogel de polyacrylamide : rapport d'un cas récent et revue de la littérature.

Polyacrylamide hydrogel (PAAG) is a filler that has been strictly prohibited in France for many years. It first appeared on the market in 1980, used as an injectable for breast and facial augmentation, mainly in Asia and Eastern Europe. Like many other materials, it has shown unfavourable results and complications due to a foreign body reaction. It was banned in 2006, but continues to be injected illegally. With the influx of migrants, we are faced with the problem of how to manage complications, which can occur more than a decade later. We report our experience of a recent case in our department that required complete removal of the product and iterative lipofilling, with a result that remains sub-optimal, and we systematically review the literature.

A Novel Indicator Based on Polyacrylamide Hydrogel and Bromocresol Green for Monitoring the Total Volatile Basic Nitrogen of Fish.

An intelligent indicator was developed by immobilizing bromocresol green (BCG) within the polyacrylamide (PAAm) hydrogel matrix to monitor the total volatile basic nitrogen (TVB-N) content of fish. The FTIR analysis indicated that BCG was effectively incorporated into the PAAm through the formation of intermolecular hydrogen bonds. A thermogravimetric analysis (TGA) showed that the PAAm/BCG indicator had a mere 0.0074% acrylamide monomer residue, meanwhile, the addition of BCG improved the thermal stability of the indicator. In vapor tests with various concentrations of trimethylamine, the indicator performed similarly at both 4 °C and 25 °C. The total color difference values (ΔE) exhibited a significant linear response to TVB-N levels ranging from 4.29 to 30.80 mg/100 g at 4 °C (R2 = 0.98). Therefore, the PAAm/BCG indicator demonstrated stable and sensitive color changes based on pH variations and could be employed in smart packaging for real-time assessment of fish freshness.

Superhydrophilic CoFe Dispersion of Hydrogel Electrocatalysts for Quasi-Solid-State Photoelectrochemical Water Splitting.

Photoelectrochemical (PEC) water splitting is an attractive strategy to convert solar energy to hydrogen. However, the lifetime of PEC devices is restricted by the photocorrosion of semiconductors and the instability of co-catalysts. Herein, we report a feasible in situ inherent cross-linking method for stabilizing semiconductors that uses a CoFe-dispersed polyacrylamide (PAM) hydrogel as a transparent protector. The CoFe-PAM hydrogel protected BiVO4 (BVO) photoanode reached a photocurrent density of 5.7 mA cm-2 at 1.23 VRHE under AM 1.5G illumination with good stability. The PAM hydrogel network improved the loading of Fe sites while enabling the retention of more CoFe co-catalysts and increasing the electron density of the reaction active sites, further improving the PEC performance and stability. More importantly, by tuning the polymerization network, we pioneer the use of quasi-solid-state electrolytes in photoelectrochemistry, where the high concentration of ionic solvent in the PAM hydrogel ensures effective charge transport and good water storage owing to the hydrophilic and porous structure of the hydrogel. This work expands the scope of PEC research by providing a class of three-dimensional hydrogel electrocatalysts and quasi-solid-state electrolytes with huge extension potential, and the versatility of these quasi-solid-state electrolytes can be employed for other semiconductors.

Quality of life and sexual function after tension-free vaginal tape and polyacrylamide hydrogel injection for primary stress urinary incontinence: 3-year follow-up from a randomized clinical trial.

INTRODUCTION AND HYPOTHESIS: To assess quality of life (QoL) and sexual function outcomes at 3 years after tension-free vaginal tape (TVT) and polyacrylamide hydrogel injection (PAHG) for stress urinary incontinence (SUI). METHODS: In this randomized trial comparing TVT (n = 104) and PAHG (n = 108), we assessed changes in QoL and sexuality using the Urogenital Distress Inventory (UDI-6), Incontinence Impact Questionnaire, Short Form (IIQ-7), Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire (PISQ-12) and RAND-36 Item Health Survey (RAND-36) at baseline and at 3 years. This is a secondary analysis of a randomized, noninferiority trial comparing patient satisfaction after TVT and PAHG. RESULTS: In both groups, incontinence-related QoL improved from the baseline (p < 0.00), except for difficulty emptying the bladder and pain/discomfort. Total scores of UDI-6 and IIIQ-7 were lower for TVT compared to PAHG (p < 0.00) indicating better QoL at 3 years. Urinary incontinence with sexual activity or fear of incontinence restricting sexual activity improved in both groups (p < 0.00), with higher scores for physical section subscale in PISQ-12 (p = 0.02) for TVT. Physical and social functioning (RAND-36) improved from the baseline in both groups (p < 0.01) with a better outcome in the TVT group for physical functioning (p = 0.00). CONCLUSIONS: Both TVT and PAHG improve QoL and sexual function in primary SUI with better incontinence and health-related QoL scores in the TVT group compared to the PAHG group at 3 years.

Green Synthesis of Silver Nanoparticles Loaded Hydrogel for Wound Healing; Systematic Review.

Wound healing is a biological process that involves a series of consecutive process, and its impairment can lead to chronic wounds and various complications. Recently, there has been a growing interest in employing nanotechnology to enhance wound healing. Silver nanoparticles (AgNPs) have expanded significant attention due to their wide range of applications in the medical field. The advantages of AgNPs include their easy synthesis, change their shape, and high surface area. Silver nanoparticles are very efficient for topical drug administration and wound healing because of their high ratio of surface area to volume. The efficiency of AgNPs depends on the synthesis method and the intended application. Green synthesis methods offer an eco-friendly approach by utilizing natural sources such as plant extracts and fungus. The characterization of nanoparticles plays an important character, and it is accomplished through the use of several characterization methods such as UV-Vis spectroscopy, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). These techniques are employed to confirm the specific characters of the prepared Silver Nanoparticles. Additionally, the review addresses the challenges and future perspectives of utilizing green-synthesized AgNPs loaded in Polyacrylamide hydrogel for wound healing applications, including the optimization of nanoparticle size, and release kinetics. Overall, this review highlights the potential of green-synthesized AgNPs loaded in Polyacrylamide hydrogel as promising for advanced wound healing therapies. There are different approaches of usage of AgNPs for wound healing such as polyacrylamide -hydrogels, and the mechanism after their antibacterial action, have been exposed.

Multiple uptake of 99mTc-MDP in chest due to breast implant rupture in a patient with lung adenocarcinoma.

A 57-year-old woman was diagnosed as lung adenocarcinoma. 99mTc-MDP bone scan showed multiple radioactivity concentrated lesions on bilateral chest wall, which were confirmed as calcification foci after breast implant rupture by SPECT/CT. SPECT/CT could be used for differential diagnosis of breast implant rupture and malignant lesions.

Factors associated with polyacrylamide hydrogel outcomes in women with stress urinary incontinence.

Knowledge of factors associated with superior outcomes in women treated with urethral bulking agents for stress urinary incontinence (SUI) remains limited. The aim of this study was to examine associations between post-treatment outcomes in women who had undergone polyacrylamide hydrogel injections for SUI, and physiological and self-reported variables captured during pre-treatment clinical evaluation. A cross-sectional study was undertaken in female patients treated for SUI with polyacrylamide hydrogel injections by a single urologist between January 2012 and December 2019. Post-treatment outcome data were gathered in July 2020 using the Patient Global Impression of Improvement (PGI-I), Urinary Distress Inventory-short form (UDI-6), Incontinence Impact Questionnaire (IIQ7), and International Consultation on Incontinence Questionnaire Short Form (ICIQ SF). All other data were gathered from women's medical records including pre-treatment patient-reported outcomes. Associations between post-treatment outcomes and pre-treatment physiological and self-reported variables were investigated using regression models. One hundred seven of the 123 eligible patients completed post-treatment patient-reported outcome measures. Mean age was 63.1 years (range 25-93 years), and median time between first injection and follow-up was 51 months (inter-quartile range 23.5-70 months). Fifty-five (51%) women had a successful outcome based on PGI-I scores. Women with type 3 urethral hypermobility pre-treatment were more likely to report treatment success (PGI-I). Poor bladder compliance pre-treatment was associated with greater urinary distress, frequency and severity (UDI-6 and ICIQ) post-treatment. Older age was associated with worse urinary frequency and severity (ICIQ) post-treatment. Associations between patient-reported outcomes and time between first injection and follow-up were trivial and not statistically significant. Severity of pre-treatment incontinence impact (IIQ-7) was associated with worse incontinence impact post-treatment. Type 3 urethral hypermobility was associated with a successful outcome, whereas pre-treatment incontinence impact, poor bladder compliance and older age were associated with poorer self-reported outcomes. Long-term efficacy appears to hold in those who responded to initial treatment.

Eco-Friendly Preparation of Carbon-Bonded Carbon Fiber Based on Glucose-Polyacrylamide Hydrogel Derived Carbon as Binder.

Lightweight, high-temperature-resistant carbon-bonded carbon fiber (CBCF) composites with excellent thermal insulation properties are desirable materials for thermal protection systems in military and aerospace applications. Here, glucose was introduced into the polyacrylamide hydrogel to form the glucose-polyacrylamide (Glu-PAM) hydrogel. The CBCF composites were prepared using the Glu-PAM hydrogel as a brand-new binder, and the synergistic effect between glucose and acrylamide was investigated. The results showed the Glu-PAM hydrogel could limit the foaming of glucose and enhance the carbon yield of glucose. Meanwhile, the dopamine-modified chopped carbon fiber could be uniformly mixed by high-speed shearing to form a slurry with the Glu-PAM hydrogel. Finally, the slurry was successfully extruded and molded to prepare CBCF composites with a density of 0.158~0.390 g cm-3 and excellent thermal insulation performance and good mechanical properties. The compressive strength of CBCF composites with a density of 0.158 g cm-3 in the Z direction is 0.18 MPa, and the thermal conductivity in the Z direction at 25 °C and 1200 °C is 0.10 W m-1 k-1 and 0.20 W m-1 k-1, respectively. This study provided an efficient, environment-friendly, and cost-effective strategy for the preparation of CBCF composites.

Development of a Disposable Polyacrylamide Hydrogel-Based Semipermeable Membrane for Micro Ag/AgCl Reference Electrode.

Currently, Ag/AgCl-based reference electrodes are used in most electrochemical biosensors and other bioelectrochemical devices. However, standard reference electrodes are rather large and do not always fit within electrochemical cells designed for the determination of analytes in low-volume aliquots. Therefore, various designs and improvements in reference electrodes are critical for the future development of electrochemical biosensors and other bioelectrochemical devices. In this study, we explain a procedure to apply common laboratory polyacrylamide hydrogel in a semipermeable junction membrane between the Ag/AgCl reference electrode and the electrochemical cell. During this research, we have created disposable, easily scalable, and reproducible membranes suitable for the design of reference electrodes. Thus, we came up with castable semipermeable membranes for reference electrodes. Performed experiments highlighted the most suitable gel formation conditions to achieve optimal porosity. Here, Cl- ion diffusion through the designed polymeric junctions was evaluated. The designed reference electrode was also tested in a three-electrode flow system. The results show that home-built electrodes can compete with commercial products due to low reference electrode potential deviation (~3 mV), long shelf-life (up to six months), good stability, low cost, and disposability. The results show a high response rate, which makes in-house formed polyacrylamide gel junctions good membrane alternatives in the design of reference electrodes, especially for these applications where high-intensity dyes or toxic compounds are used and therefore disposable electrodes are required.

The Combined Effects of Topography and Stiffness on Neuronal Differentiation and Maturation Using a Hydrogel Platform.

Biophysical parameters such as substrate topography and stiffness have been shown independently to elicit profound effects on neuronal differentiation and maturation from neural progenitor cells (NPCs) yet have not been investigated in combination. Here, the effects of various micrograting and stiffness combinations on neuronal differentiation and maturation were investigated using a polyacrylamide and N-acryloyl-6-aminocaproic acid copolymer (PAA-ACA) hydrogel with tunable stiffness. Whole laminin was conjugated onto the PAA-ACA surface indirectly or directly to facilitate long-term mouse and human NPC-derived neuron attachment. Three micrograting dimensions (2-10 µm) were patterned onto gels with varying stiffness (6.1-110.5 kPa) to evaluate the effects of topography, stiffness, and their interaction. The results demonstrate that the extracellular matrix (ECM)-modified PAA-ACA gels support mouse and human neuronal cell attachment throughout the differentiation and maturation stages (14 and 28 days, respectively). The interaction between topography and stiffness is shown to significantly increase the proportion of ß-tubulin III (TUJ1) positive neurons and microtubule associated protein-2 (MAP2) positive neurite branching and length. Thus, the effects of topography and stiffness cannot be imparted. These results provide a novel platform for neural mechanobiology studies and emphasize the utility of optimizing numerous biophysical cues for improved neuronal yield in vitro.

Analysis of breast follow-up results in patients after polyacrylamide hydrogel (PAAG) or silicone prosthesis removal.

BACKGROUND: Polyacrylamide hydrogel has been prohibited since 2006 due to numerous complications. Unsatisfactory breast contour was always observed in patients after PAAG removal. The same occurred in patients after silicone prosthesis removal. We attempt to compare and analyze the difference in postoperative breast conditions and pathology between the two groups. METHODS: We retrospectively reviewed the data of patients who underwent PAAG or silicone prosthesis removal between 2011 and 2021. The BREAST-Q was used to evaluate the follow-up results, including satisfaction with breasts, physical well-being, psychosocial well-being, sexual well-being, and the operation. RESULTS: A total of 63 patients were analyzed. The PAAG group complained of more lumps or indurations (p = 0.004), benefited less from operations as for symptomatic relief (p = 0.002), and had more chronic inflammation(p = 0.000) than the silicone group. No breast cancer was found. All the Breast-Q scores were lower in the PAAG group than in the silicone group, and there was a significant difference in satisfaction with physical well-being (p = 0.035). Besides, patients without symptoms tended to score higher in all aspects of Breast-Q than patients with symptoms after removal. The two groups (symptom & no symptom) differed in psychosocial well-being (p = 0.043) and satisfaction with operation (p = 0.048). CONCLUSIONS: The breast contour of patients after PAAG or silicone prosthesis removal was worse than before. Early removal of PAAG before complications arise may result in a better surgical benefit. There is no doubt that PAAG are harmful both physically and psychologically. All patients are suggested to have PAAG injections removed.