Implications of polystyrene and polyamide microplastics in the adsorption of sulfonamide antibiotics and their metabolites in water matrices.

Microplastics (MP) and antibiotics coexist in the environment and their combined exposure represents a source of increasing concern. MP may act as carriers of antibiotics because of their sorption capacity. Knowledge of the interactions between them may help improve understanding of their migration and transformation. In this work, the adsorption behaviour of a group of sulfonamides and their acetylated metabolites on different sizes of polyamide (PA) and polystyrene (PS) MP were investigated and compared. Sulfonamides were adsorbed on both MP (qmax up to 0.699 and 0.184 mg/g, for PA and PS, respectively) fitting to a linear isotherm model (R2 > 0.835). A low particle size and an acidic and salinity medium significantly enhances the adsorption capacity of sulfonamides (i.e. removal of sulfamethoxazole increased from 8 % onto 3 mm PA pellets to 80 % onto 50 mm of PA pellets). According to characterization results, adsorption mechanism is explained by pore filling and hydrogen bonds (for PA) and hydrophobic interactions (for PS). After adsorption, surface area was increased in both MP as result of a potential ageing of the particles and the intensity of XRD peaks was higher denoting a MP structure more amorphized. Metabolites were adsorbed more efficiently than their parent compounds on PS while the opposite effect was observed on PA explained by the acetylation of the amine group and, subsequently the reduction of hydrogen bond interactions. Although the dissolved organic matter inhibits sulfonamides adsorption, removal up to 65.2 % in effluent wastewater and up to 72.1 % in surface water were observed in experiments using real matrices denoting the role of MP as vectors of sulfonamide antibiotics in aquatic media.

Antimicrobial activity of cleanser tablets against S. mutans and C. Albicans on different denture base materials.

BACKGROUND: In this study, the antimicrobial activity of three different cleanser tablets on S. mutans and C. albicans adhesion to PMMA, polyamide and 3D printed resin was investigated. METHODS: 40 samples were prepared for PMMA (SR Triplex Hot), polyamide (Deflex) and 3D printed resin (PowerResins Denture) materials and divided into four subgroups for cleansers (Aktident™, Protefix™, Corega™ tablets and distilled water) (n = 5). After the surface preparations were completed, the samples were immersed separately in tubes containing the prepared microorganism suspension and incubated at 37˚C for 24 h. After the incubation, the samples were kept in the cleanser solutions. The samples were then transferred to sterile saline tubes. All the tubes were vortexed and 10 µl was taken from each of them. Sheep blood agar was inoculated for colony counting. The inoculated plates were incubated for 48 h for S. mutans and 24 h for C. albicans. After incubation, colonies observed on all plates were counted. Statistical analyses were done with three-way ANOVA and Tukey's multiple comparison test. RESULTS: Polyamide material registered the highest colony count of S. mutans, whereas PMMA registered the lowest. Significant differences in S. mutans adherence (p = 0.002) were found between the three denture base materials, but no such difference in C. albicans adherence (p = 0.221) was identified between the specimens. All three cleanser tablets eliminated 98% of S. mutans from all the material groups. In all these groups, as well, the antifungal effect of Corega™ on C. albicans was significantly higher than those of the other two cleanser tablets. CONCLUSIONS: According to the study's results, it may be better to pay attention to surface smoothness when using polyamide material to prevent microorganism retention. Cleanser tablets are clinically recommended to help maintain hygiene in removable denture users, especially Corega tablets that are more effective on C. albicans.

Injectable polyamide-amine dendrimer-crosslinked meloxicam-containing poly-γ-glutamic acid hydrogel for prevention of postoperative tissue adhesion through inhibiting inflammatory responses and balancing the fibrinolytic system.

Establishing a physical barrier between the peritoneum and the cecum is an effective method to reduce the risk of postoperative abdominal adhesions. Meloxicam (MX), a nonsteroidal anti-inflammatory drug has also been applied to prevent postoperative adhesions. However, its poor water solubility has led to low bioavailability. Herein, we developed an injectable hydrogel as a barrier and drug carrier for simultaneous postoperative adhesion prevention and treatment. A third-generation polyamide-amine dendrimer (G3) was exploited to dynamically combine with MX to increase the solubility and the bioavailability. The formed G3@MX was further used to crosslink with poly-γ-glutamic acid (γ-PGA) to prepare a hydrogel (GP@MX hydrogel) through the amide bonding. In vitro and in vivo experiments evidenced that the hydrogel had good biosafety and biodegradability. More importantly, the prepared hydrogel could control the release of MX, and the released MX is able to inhibit inflammatory responses and balance the fibrinolytic system in the injury tissues in vivo. The tunable rheological and mechanical properties (compressive moduli: from âˆ¼ 57.31 kPa to âˆ¼ 98.68 kPa;) and high anti-oxidant capacity (total free radical scavenging rate of âˆ¼ 94.56 %), in conjunction with their syringeability and biocompatibility, indicate possible opportunities for the development of advanced hydrogels for postoperative tissue adhesions management.

Covalently grafting polycation to bacterial cellulose for antibacterial and anti-cell adhesive wound dressings.

Hydrogel-based wound dressings are becoming increasingly important for wound healing. Bacterial cellulose (BC) has been commonly used as wound dressings due to its good in vitro and in vivo biocompatibility. However, pure BC does not possess antibacterial properties. In this regard, polycation gel was grafted onto the BC using a surface-initiated activator regenerated by electron transfer atom transfer radical polymerization (SI-ARGET ATRP) with subsequent quaternization for antibacterial wound dressing. Dimethylethyl methacrylate (DMAEMA) was successfully polymerized on the BC surface which was confirmed by Fourier transform infrared spectroscopy and elemental analysis. The morphology structure, specific surface area, pore size, and mechanical properties were also characterized. The quaternized PDMAEMA grafted on the BC endowed it with excellent antibacterial activity against E. coli (Gram-negative) and S. aureus (Gram-positive) with a killing rate of 89.2 % and 93.4 %, respectively. The number of cells was significantly reduced on QPD/BC hydrogel, demonstrating its good anti-adhesion ability. In vitro cellular evaluation revealed that the antibacterial wound dressing exhibited good biocompatibility. Overall, this study provides a feasible method to develop antibacterial and anti-cell adhesive hydrogel, which has a promising potential for wound healing.

Preparation and characterization of cellulose fluorescent material: Experiment and simulation.

The extensive use of fossil based materials has caused serious pollution problems, the full utilization of biomass resources to prepare high value-added new materials is of great significance for the environmental protection and sustainable social development. For this purpose, this study explored the preparation process and molecular dynamics simulation of cellulose fluorescent materials. Firstly, bacterial cellulose was dissolved in a solution of NaOH and urea at low temperature, followed by a solution blending and hot pressing with hyperbranched polyamide. It was found that the addition of hyperbranched polyamide could effectively filled in the internal pores of cellulose hydrogel, thereby enhancing the fluorescence effects and tensile properties, especially the elongation at break of cellulose materials. The optimal amount of hyperbranched polyamide added was 5 wt%. Molecular dynamics simulation showed that the hydrogen bonds and interaction with cellulose increased as the concentration of hyperbranched polyamide increased.

Double-nylon purse-string suture in closing postoperative wounds following endoscopic resection of large (≥ 3 cm) gastric submucosal tumors.

BACKGROUND: Endoscopic full-thickness resection (EFTR) of gastric submucosal tumors (SMTs) is safe and effective; however, postoperative wound management is equally important. Literature on suturing following EFTR for large (≥ 3 cm) SMTs is scarce and limited. AIM: To evaluate the efficacy and clinical value of double-nylon purse-string suture in closing postoperative wounds following EFTR of large (≥ 3 cm) SMTs. METHODS: We retrospectively analyzed the data of 85 patients with gastric SMTs in the fundus of the stomach or in the lesser curvature of the gastric body whose wounds were treated with double-nylon purse-string sutures after successful tumor resection at the Endoscopy Center of Renmin Hospital of Wuhan University. The operative, postoperative, and follow-up conditions of the patients were evaluated. RESULTS: All tumors were completely resected using EFTR. 36 (42.35%) patients had tumors located in the fundus of the stomach, and 49 (57.65%) had tumors located in the body of the stomach. All patients underwent suturing with double-nylon sutures after EFTR without laparoscopic assistance or further surgical treatment. Postoperative fever and stomach pain were reported in 13 (15.29%) and 14 (16.47%) patients, respectively. No serious adverse events occurred during the intraoperative or postoperative periods. A postoperative review of all patients revealed no residual or recurrent lesions. CONCLUSION: Double-nylon purse-string sutures can be used to successfully close wounds that cannot be completely closed with a single nylon suture, especially for large (≥ 3 cm) EFTR wounds in SMTs.

Scalable Preparation of Ultraselective and Highly Permeable Fully Aromatic Polyamide Nanofiltration Membranes for Antibiotic Desalination.

Membranes are important in the pharmaceutical industry for the separation of antibiotics and salts. However, its widespread adoption has been hindered by limited control of the membrane microstructure (pore architecture and free-volume elements), separation threshold, scalability, and operational stability. In this study, 4,4',4'',4'''-methanetetrayltetrakis(benzene-1,2-diamine) (MTLB) as prepared as a molecular building block for fabricating thin-film composite membranes (TFCMs) via interfacial polymerization. The relatively large molecular size and rigid molecular structure of MTLB, along with its non-coplanar and distorted conformation, produced thin and defect-free selective layers (~27 nm) with ideal microporosities for antibiotic desalination. These structural advantages yielded an unprecedented high performance with a water permeance of 45.2 L m-2 h-1 bar-1 and efficient antibiotic desalination (NaCl/adriamycin selectivity of 422). We demonstrated the feasibility of the industrial scaling of the membrane into a spiral-wound module (with an effective area of 2.0 m2). This module exhibited long-term stability and performance that surpassed those of state-of-the-art membranes used for antibiotic desalination. This study provides a scientific reference for the development of high-performance TFCMs for water purification and desalination in the pharmaceutical industry.

Strong, Tough, and Biocompatible Poly(vinyl alcohol)-Poly(vinylpyrrolidone) Multiscale Network Hydrogels Reinforced by Aramid Nanofibers.

Poly(vinyl alcohol) (PVA) hydrogels are water-rich, three-dimensional (3D) network materials that are similar to the tissue structure of living organisms. This feature gives hydrogels a wide range of potential applications, including drug delivery systems, articular cartilage regeneration, and tissue engineering. Due to the large amount of water contained in hydrogels, achieving hydrogels with comprehensive properties remains a major challenge, especially for isotropic hydrogels. This study innovatively prepares a multiscale-reinforced PVA hydrogel from molecular-level coupling to nanoscale enhancement by chemically cross-linking poly(vinylpyrrolidone) (PVP) and in situ assembled aromatic polyamide nanofibers (ANFs). The optimized ANFs-PVA-PVP (APP) hydrogels have a tensile strength of ≈9.7 MPa, an elongation at break of ≈585%, a toughness of ≈31.84 MJ/m3, a compressive strength of ≈10.6 MPa, and a high-water content of ≈80%. It is excellent among all reported PVA hydrogels and even comparable to some anisotropic hydrogels. System characterizations show that those performances are attributed to the particular multiscale load-bearing structure and multiple interactions between ANFs and PVA. Moreover, APP hydrogels exhibit excellent biocompatibility and a low friction coefficient (≈0.4). These valuable performances pave the way for broad potential in many advanced applications such as biological tissue replacement, flexible wearable devices, electronic skin, and in vivo sensors.

Clean synthesis of silver nanoparticles (AgNPs) on polyamide fabrics by Verbascum thapsus L. (mullein) extract: characterization, colorimetric, antibacterial, and colorfastness studies.

The production of antibacterial colored textiles using nanomaterials (NMs) has become an ideal goal from both a research and industrial perspective. In this study, the clean synthesis and characterization of silver nanoparticles (AgNPs) on polyamide fabrics were performed using mullein extract for the first time. Natural dyes were extracted from mullein leaves using an ultrasonic method, with an optimal amount of 15 g/L. The synthesized AgNPs in different ratios of mullein extract and Ag ions were analyzed (using UV-visible spectroscopy) and dynamic light scattering (DLS). It was found that AgNPs synthesized with a ratio of 1:4 of mullein extract: to Ag ions had a diameter of 85 nm. The active site groups of the synthesized AgNPs were characterized using Fourier transform infrared spectroscopy (FT-IR). Nylon fabrics dyed with different ratios of mullein extract and Ag ions exhibited acceptable color strength values (K/S) of 3.36. Furthermore, the reduction in bacterial growth for dyed fabrics improved with an increase in the ratio of Ag ions, with a 100% reduction observed for a sample dyed with mullein extract: Ag ions at a ratio of 1:4. Overall, this method offers a simple, low-cost, and compatible process with environment without the consumption of any chemicals to producing nylon with acceptable antibacterial and dyeing properties.

Trade-off between Endocrine-Disrupting Compound Removal and Water Permeance of the Polyamide Nanofiltration Membrane: Phenomenon and Molecular Insights.

The polyamide (PA) nanofiltration (NF) membrane has the potential to remove endocrine-disrupting compounds (EDCs) from water and wastewater to prevent risks to both the aquatic ecosystem and human health. However, our understanding of the EDC removal-water permeance trade-off by the PA NF membrane is still limited, although the salt selectivity-water permeance trade-off has been well illustrated. This constrains the precise design of a high-performance membrane for removing EDCs. In this study, we manipulated the PA nanostructures of NF membranes by altering piperazine (PIP) monomer concentrations during the interfacial polymerization (IP) process. The upper bound coefficient for EDC selectivity-water permeance was demonstrated to be more than two magnitudes lower than that for salt selectivity-water permeance. Such variations were derived from the different membrane-solute interactions, in which the water/EDC selectivity was determined by the combined effects of steric exclusion and the hydrophobic interaction, while the electrostatic interaction and steric exclusion played crucial roles in water/salt selectivity. We further highlighted the role of the pore number and residual groups during the transport of EDC molecules across the PA membrane via molecular dynamics (MD) simulations. Fewer pores decreased the transport channels, and the existence of residual groups might cause steric hindrance and dynamic disturbance to EDC transport inside the membrane. This study elucidated the trade-off phenomenon and mechanisms between EDC selectivity and water permeance, providing a theoretical reference for the precise design of PA NF membranes for effective removal of EDCs in water reuse.

Engraving Polyamide Layers by In Situ Self-Etchable CaCO3 Nanoparticles Enhances Separation Properties and Antifouling Performance of Reverse Osmosis Membranes.

Nanovoids within a polyamide layer play an important role in the separation performance of thin-film composite (TFC) reverse osmosis (RO) membranes. To form more extensive nanovoids for enhanced performance, one commonly used method is to incorporate sacrificial nanofillers in the polyamide layer during the exothermic interfacial polymerization (IP) reaction, followed by some post-etching processes. However, these post-treatments could harm the membrane integrity, thereby leading to reduced selectivity. In this study, we applied in situ self-etchable sacrificial nanofillers by taking advantage of the strong acid and heat generated in IP. CaCO3 nanoparticles (nCaCO3) were used as the model nanofillers, which can be in situ etched by reacting with H+ to leave void nanostructures behind. This reaction can further degas CO2 nanobubbles assisted by heat in IP to form more nanovoids in the polyamide layer. These nanovoids can facilitate water transport by enlarging the effective surface filtration area of the polyamide and reducing hydraulic resistance to significantly enhance water permeance. The correlations between the nanovoid properties and membrane performance were systematically analyzed. We further demonstrate that the nCaCO3-tailored membrane can improve membrane antifouling propensity and rejections to boron and As(III) compared with the control. This study investigated a novel strategy of applying self-etchable gas precursors to engrave the polyamide layer for enhanced membrane performance, which provides new insights into the design and synthesis of TFC membranes.

Characterization of microplastic-derived dissolved organic matter in freshwater: Effects of light irradiation and polymer types.

This study investigated the impacts of light irradiation and polymer types on the leaching behavior of dissolved organic matter (DOM) from microplastics (MPs) in freshwater. Polypropylene had the highest leaching capacity of DOM after photoaging, followed by polystyrene (PS), polyamide (PA) and polyethylene terephthalate (PET). While similarly low levels of DOM were observed in the remaining 5 MP suspensions under UV irradiation and in almost all MP suspensions (except PA) under darkness. These suggest that the photooxidation of some buoyant plastics may influence the carbon cycling of nature waters. Among 9 MP-derived leachates, PET leachates had the highest chromophoric DOM concentration and aromaticity, probably owing to the special benzene rings and carbonyl groups in PET structures and its fast degradation rate. Protein-like substances were the primary fluorescent DOM in MP suspensions (except PS), especially in darkness no other fluorescent substances were found. Considering the bio-labile properties of proteins together, MPs regardless of floating or suspended in an aquatic environment may have prevalent long-term effects on microbial activities. Besides, from monomers to hexamers with newly formed chemical bonds were identified in UV-irradiated MP suspensions. These results will contribute to a deep insight into the potential ecological effects related to MP degradation.

Settling Velocities of Small Microplastic Fragments and Fibers.

There is only sparse empirical data on the settling velocity of small, nonbuoyant microplastics thus far, although it is an important parameter governing their vertical transport within aquatic environments. This study reports the settling velocities of 4031 exemplary microplastic particles. Focusing on the environmentally most prevalent particle shapes, irregular microplastic fragments of four different polymer types (9-289 µm) and five discrete length fractions (50-600 µm) of common nylon and polyester fibers are investigated, respectively. All settling experiments are carried out in quiescent water by using a specialized optical imaging setup. The method has been previously validated in order to minimize disruptive factors, e.g., thermal convection or particle interactions, and thus enable the precise measurements of the velocities of individual microplastic particles (0.003-9.094 mm/s). Based on the obtained data, ten existing models for predicting a particle's terminal settling velocity are assessed. It is concluded that models, which were specifically deduced from empirical data on larger microplastics, fail to provide accurate predictions for small microplastics. Instead, a different approach is highlighted as a viable option for computing settling velocities across the microplastics continuum in terms of size, density, and shape.

Development and Characterization of Transdermal Patches Using Novel Thymoquinone-L-Arginine-Based Polyamide Nanocapsules for Potential Use in the Management of Psoriasis.

Thymoquinone (TQ) is a phytochemical compound present in Nigella sativa and has potential benefits for treating dermatological conditions such as psoriasis. However, its clinical use is limited due to its restricted bioavailability, caused mainly by its low solubility and permeability. To overcome this, a new transdermal drug delivery system is required. Nanoparticles are known to enhance material solubility and permeability, and hence, this study aimed to synthesize TQ-loaded L-arginine-based polyamide (TQ/Arg PA) nanocapsules incorporated into transdermal patches for prolonged delivery of TQ. To achieve this, Eudragit E polymer, plasticizers, and aloe vera as penetration enhancer were used to develop the transdermal patch. Furthermore, novel TQ/Arg-PA was synthesized via interfacial polymerization, and the resultant nanocapsules (NCs) were incorporated into the matrix transdermal patch. The Arg-PA NCs' structure was confirmed via NMR and FTIR, and optimal TQ/Arg-PA NCs containing formulation showed high entrapment efficiency of TQ (99.60%). Molecular and thermal profiling of TQ/Arg-PA and the transdermal patch revealed the effective development of spherical NCs with an average particle size of 129.23 ± 18.22 nm. Using Franz diffusion cells and synthetic membrane (STRAT M®), the in vitro permeation profile of the prepared patches demonstrated an extended release of TQ over 24 h, with enhanced permeation by 42.64% when aloe vera was employed. In conclusion, the produced formulation has a potential substitute for corticosteroids and other drugs commonly used to treat psoriasis due to its effectiveness, safety, and lack of the side effects typically associated with other drugs.

Enhanced water treatment performance of ceramic-based forward osmosis membranes via MOF interlayer.

Forward osmosis (FO) membrane processes could operate without hydraulic pressures, enabling the efficient treatment of wastewaters with mitigated membrane fouling and enhanced efficiency. Designing a high-performance polyamide (PA) layer on ceramic substrates remains a challenge for FO desalination applications. Herein, we report the enhanced water treatment performance of thin-film nanocomposite ceramic-based FO membranes via an in situ grown Zr-MOF (UiO-66-NH2) interlayer. With the Zr-MOF interlayer, the ceramic-based FO membranes exhibit lower thickness, higher cross-linking degree, and increased surface roughness, leading to higher water flux of 27.38 L m-2 h-1 and lower reverse salt flux of 3.45 g m-2 h-1. The ceramic-based FO membranes with Zr-MOF interlayer not only have an application potential in harsh environments such as acidic solution (pH 3) and alkaline solution (pH 11), but also exhibit promising water and reverse salt transport properties, which are better than most MOF-incorporated PA membranes. Furthermore, the membranes could reject major species (ions, oil and organics) with rejections ＞94 % and water flux of 22.62-14.35 L m-2 h-1 in the treatment of actual alkaline industrial wastewater (pH 8.6). This rational design proposed in this study is not only applicable for the development of a high-quality ceramic-based FO membrane with enhanced performance but also can be potentially extended to more challenging water treatment applications.

Mass quantification of nanoplastics at wastewater treatment plants by pyrolysis-gas chromatography-mass spectrometry.

Municipal wastewater treatment plants (WWTPs) play a crucial role in the collection and redistribution of plastic particles from both households and industries, contributing to their presence in the environment. Previous studies investigating the levels of plastics in WWTPs, and their removal rates have primarily focused on polymer type, size, shape, colour, and particle count, while comprehensive understanding of the mass concentration of plastic particles, particularly those <1 µm (nanoplastics), remains unclear and lacking. In this study, pyrolysis gas chromatography-mass spectrometry was used to simultaneously determine the mass concentration of nine selected polymers (i.e., polyethylene (PE), polypropylene (PP), polystyrene (PS), poly(ethylene terephthalate) (PET), nylon 6, nylon 66, polyvinylchloride (PVC), poly(methyl methacrylate) (PMMA) and polycarbonate (PC)) below 1 µm in size across the treatment processes or stages of three WWTPs in Australia. All the targeted nanoplastics were detected at concentrations between 0.04 and 7.3 µg/L. Nylon 66 (0.2-7.3 µg/L), PE (0.1-6.6 µg/L), PP (0.1-4.5 µg/L), Nylon 6 (0.1-3.6 µg/L) and PET (0.1-2.2 µg/L), were the predominant polymers in the samples. The mass concentration of the total nanoplastics decreased from 27.7, 18 and 9.1 µg/L in the influent to 1, 1.4 and 0.8 µg/L in the effluent, with approximate removal rates of 96 %, 92 % and 91 % in plants A, B and C, respectively. Based on annual wastewater effluent discharge, it is estimated that approximately 24, 2 and 0.7 kg of nanoplastics are released into the environment per year for WWTPs A, B and C, respectively. This study investigated the mass concentrations and removal rates of nanoplastics with a size range of 0.01-1 µm in wastewater, providing important insight into the pollution levels and distribution patterns of nanoplastics in Australian WWTPs.

Polyamide Membranes with Tunable Surface Charge Induced by Dipole-Dipole Interaction for Selective Ion Separation.

Nanofiltration (NF) has the potential to achieve precise ion-ion separation at the subnanometer scale, which is necessary for resource recovery and a circular water economy. Fabricating NF membranes for selective ion separation is highly desirable but represents a substantial technical challenge. Dipole-dipole interaction is a mechanism of intermolecular attractions between polar molecules with a dipole moment due to uneven charge distribution, but such an interaction has not been leveraged to tune membrane structure and selectivity. Herein, we propose a novel strategy to achieve tunable surface charge of polyamide membrane by introducing polar solvent with a large dipole moment during interfacial polymerization, in which the dipole-dipole interaction with acyl chloride groups of trimesoyl chloride (TMC) can successfully intervene in the amidation reaction to alter the density of surface carboxyl groups in the polyamide selective layer. As a result, the prepared positively charged (PEI-TMC)-NH2 and negatively charged (PEI-TMC)-COOH composite membranes, which show similarly high water permeance, demonstrate highly selective separations of cations and anions in engineering applications, respectively. Our findings, for the first time, confirm that solvent-induced dipole-dipole interactions are able to alter the charge type and density of polyamide membranes and achieve tunable surface charge for selective and efficient ion separation.

Using synthetic genome readers/regulators to interrogate chromatin processes: A brief review.

Aberrant gene expression underlies numerous human ailments. Hence, developing small molecules to target and remedy dysfunctional gene regulation has been a long-standing goal at the interface of chemistry and medicine. A major challenge for designing small molecule therapeutics aimed at targeting desired genomic loci is the minimization of widescale disruption of genomic functions. To address this challenge, we rationally design polyamide-based multi-functional molecules, i.e., Synthetic Genome Readers/Regulators (SynGRs), which, by design, target distinct sequences in the genome. Herein, we briefly review how SynGRs access chromatin-bound and chromatin-free genomic sites, then highlight the methods for the study of chromatin processes using SynGRs on positioned nucleosomes in vitro or disease-causing repressive genomic loci in vivo.

An evaluation of the usability and durability of 3D printed versus standard suture materials.

The capability to produce suture material using three-dimensional (3D) printing technology may have applications in remote health facilities where rapid restocking of supplies is not an option. This is a feasibility study evaluating the usability of 3D-printed sutures in the repair of a laceration wound when compared with standard suture material. The 3D-printed suture material was manufactured using a fused deposition modelling 3D printer and nylon 3D printing filament. Study participants were tasked with performing laceration repairs on the pigs' feet, first with 3-0 WeGo nylon suture material, followed by the 3D-printed nylon suture material. Twenty-six participants were enrolled in the study. Survey data demonstrated statistical significance with how well the 3D suture material performed with knot tying, 8.9 versus 7.5 (p = 0.0018). Statistical significance was observed in the 3D-printed suture's ultimate tensile strength when compared to the 3-0 Novafil suture (274.8 vs. 199.8 MPa, p = 0.0096). The 3D-printed suture also demonstrated statistical significance in ultimate extension when compared to commercial 3-0 WeGo nylon suture (49% vs. 37%, p = 0.0215). This study was successful in using 3D printing technology to manufacture suture material and provided insight into its usability when compared to standard suture material.