A Clinical Study of Antibacterial Medical Textiles Containing Polyhydroxyalkanoate Oligomers for Reduction of Hospital-Acquired Infections.

INTRODUCTION: The prevention and control of hospital-acquired infections remain a significant challenge worldwide, as textiles used in hospital wards are highly involved in transmission processes. Herein, we report a new antibacterial medical fabric used to prepare hospital pillowcases, bottom sheets, and quilt covers for controlling and reducing hospital-acquired infections. METHOD: The medical fabric was composed of blended yarns of staple polyester and degradable poly(3-hydroxybutyrate co-3-hydroxyvalerate)/polylactide fibres, which were then coated with polylactide oligomers, an environmentally friendly and safe antimicrobial agent with excellent thermal stability in high-temperature laundry. A clinical trial was conducted with emphasis on the bacterial species that were closely related to the infection cases in the trial hospital. RESULT: After 7 days of usage, 94% of PET/PHBV/PLA-PLAO fabric could keep less than 20 CFU/100 cm2 of total bacterial amount, meeting hygiene and cleanliness standards. CONCLUSION: This study demonstrates the potential of fabrics containing polyhydroxyalkanoate oligomers as highly effective, safe, and long-lasting antimicrobial medical textiles that can effectively reduce the incidence of hospital-acquired infections.

Green moisture-electric generator based on supramolecular hydrogel with tens of milliamp electricity toward practical applications.

Moisture-electric generators (MEGs) has emerged as promising green technology to achieve carbon neutrality in next-generation energy suppliers, especially combined with ecofriendly materials. Hitherto, challenges remain for MEGs as direct power source in practical applications due to low and intermittent electric output. Here we design a green MEG with high direct-current electricity by introducing polyvinyl alcohol-sodium alginate-based supramolecular hydrogel as active material. A single unit can generate an improved power density of ca. 0.11 mW cm-2, a milliamp-scale short-circuit current density of ca. 1.31 mA cm-2 and an open-circuit voltage of ca. 1.30 V. Such excellent electricity is mainly attributed to enhanced moisture absorption and remained water gradient to initiate ample ions transport within hydrogel by theoretical calculation and experiments. Notably, an enlarged current of ca. 65 mA is achieved by a parallel-integrated MEG bank. The scalable MEGs can directly power many commercial electronics in real-life scenarios, such as charging smart watch, illuminating a household bulb, driving a digital clock for one month. This work provides new insight into constructing green, high-performance and scalable energy source for Internet-of-Things and wearable applications.

A multimodal physiological dataset for driving behaviour analysis.

Physiological signal monitoring and driver behavior analysis have gained increasing attention in both fundamental research and applied research. This study involved the analysis of driving behavior using multimodal physiological data collected from 35 participants. The data included 59-channel EEG, single-channel ECG, 4-channel EMG, single-channel GSR, and eye movement data obtained via a six-degree-of-freedom driving simulator. We categorized driving behavior into five groups: smooth driving, acceleration, deceleration, lane changing, and turning. Through extensive experiments, we confirmed that both physiological and vehicle data met the requirements. Subsequently, we developed classification models, including linear discriminant analysis (LDA), MMPNet, and EEGNet, to demonstrate the correlation between physiological data and driving behaviors. Notably, we propose a multimodal physiological dataset for analyzing driving behavior(MPDB). The MPDB dataset's scale, accuracy, and multimodality provide unprecedented opportunities for researchers in the autonomous driving field and beyond. With this dataset, we will contribute to the field of traffic psychology and behavior.

TBEEG: A Two-Branch Manifold Domain Enhanced Transformer Algorithm for Learning EEG Decoding.

The electroencephalogram-based (EEG) brain-computer interface (BCI) has garnered significant attention in recent research. However, the practicality of EEG remains constrained by the lack of efficient EEG decoding technology. The challenge lies in effectively translating intricate EEG into meaningful, generalizable information. EEG signal decoding primarily relies on either time domain or frequency domain information. There lacks a method capable of simultaneously and effectively extracting both time and frequency domain features, as well as efficiently fuse these features. Addressing these limitations, a two-branch Manifold Domain enhanced transformer algorithm is designed to holistically capture EEG's spatio-temporal information. Our method projects the time-domain information of EEG signals into the Riemannian spaces to fully decode the time dependence of EEG signals. Using wavelet transform, the time domain information is converted into frequency domain information, and the spatial information contained in the frequency domain information of EEG signal is mined through the spectrogram. The effectiveness of the proposed TBEEG algorithm is validated on BCIC-IV-2a dataset and MAMEM-SSVEP-II datasets.

A randomized controlled trial of standard vs customized graduated elastic compression stockings in patients with chronic venous disease.

OBJECTIVE: This study aimed to compare the efficacy of customized graduated elastic compression stockings (c-GECSs) based on lower leg parameter models with standard GECSs (s-GECSs) in patients with chronic venous disease (CVD). METHODS: In this randomized, single-blind, controlled trial, 79 patients with stage C2 or C3 CVD were assigned to one of two groups: c-GECSs or s-GECSs. The primary outcome was change to Venous Insufficiency Epidemiological and Economic Study Quality of Life (VEINES-QOL) scores at months 1, 3, and 6 as compared with baseline. Secondary outcomes included compliance with wearing ECSs, interface pressure at the smallest circumference of the ankle (point B) and the largest circumference of the calf (point C), and calf volume (CV). RESULTS: There were 13 pairs of s-GECS and 2 pairs of c-GECS that showed pressure values higher than the standard at either point B or C. The c-GECSs were significantly superior to s-GECSs in terms of score improvement at all three time points (month 1, 8.47 [95% confidence interval (CI), 7.47-9.45] vs 5.89 [95% CI, 5.00-6.78]; month 3, 9.60 [95% CI, 8.47-10.72] vs 6.72 [95% CI, 5.62-7.83]; month 6, 7.09 [95% CI, 5.93-8.24] vs 3.92 [95% CI, 2.67-5.18]; P < .0001). Besides, at month 1, the mean daily use time of the c-GECS and s-GECS groups was 10.7 and 9.5 hours, respectively (P < .05). Correlation analysis indicated a negative relationship between local high pressure and daily duration in the s-GECS group (rpb = -0.388; n = 38; P < .05). Variances in pressure were greater in the s-GECSs group. The c-GECSs showed advantage in maintaining pressure. Both c-GECSs and s-GECSs effectively reduced CV (mL), with no significant differences between groups (month 1, 90.0 [95% CI, 71.4-108.5] vs 85.0 [95% CI, 65.6-104.2]; month 3, 93.8 [95% CI, 69.7-117.8] vs 85.9 [95% CI, 65.5-106.2]; month 6, 70.8 [95% CI, 46.5-95.2]) vs 60.8 [95% CI, 44.1-77.5]). CONCLUSIONS: The c-GECSs based on individual leg parameter models significantly improved VEINES-QOL scores and provided stable and enduring pressure as compared with s-GECSs for patients with stage C2 or C3 CVD. Although both c-GECSs and s-GECSs effectively reduced CV, the superior fit and comfort of c-GECSs improved patient compliance. Hence, c-GECSs are a viable alternative for patients who have difficulty tolerating s-GECSs.

The value of ultrasensitive C-reactive protein and homocysteine levels in predicting the diagnosis and functional prognostic assessment of cerebral infarction in the elderly.

OBJECTIVE: To evaluate the diagnostic value of ultrasensitive C-reactive protein (hs-CRP) and homocysteine (Hcy) for cerebral infarction. METHODS: 260 elderly patients with cerebral infarction were recruited and assigned to the stroke group, and 60 healthy elderly were identified as controls and included in the normal group. Serum samples of all subjects were collected at the time of admission for the determination of hs-CRP and Hcy levels. RESULTS: Patients with cerebral infarction exhibited significantly higher hs-CRP and Hcy levels than healthy controls. the patients were then categorized into mild-moderate and moderate-severe groups according to the National Institutes of Health Stroke Scale (NIHSS) score. No significant association was identified between Hcy levels and infarction severity, while more severe infarction was potentially related to higher hs-CRP levels, as evidenced by the higher hs-CRP levels observed in patients with moderate-severe infarction versus a milder severity. Patients with disease recurrence within 2 years were also included in a recurrence group, while those without recurrence were in a non-recurrence group. Results showed that patients with or without disease recurrence had similar hs-CRP and Hcy levels. CONCLUSION: In elderly patients with cerebral infarction, serum hs-CRP, and Hcy levels are potentially promising markers for the diagnosis of stroke, assessment of stroke severity, and prediction of functional recovery. hs-CRP provides more benefits in diagnosing cerebral infarction, and Hcy is more conducive to the assessment of stroke severity and prediction of functional recovery. Combined detection of the two indices did not offer additional benefits in diagnostic and predictive efficacy.

Gigantic and Continuous Output Power in Ionic Thermo-Electrochemical Cells by Using Electrodes with Redox Couples.

The main obstacle of ionic thermo-electrochemical cells (TECs) in continuous power supply lies in a low heat-to-electricity energy conversion efficiency because most TECs work in thermodiffusion mode in which the ions are confined in a liquid/electrolyte media. The introduction of the redox couple onto the electrode surface may overcome the obstacle by resolving the low mass transport rate of ions caused by the redox process occurring near but not on the electrode surface. Herein, the authors demonstrate enhancement of TECs by integrating the redox couple directly onto the electrode surface to maximize the mass transport efficiency. A discontinuous interfacial modification strategy is developed by using a carbon cloth/iron (II/III) phytate as the symmetric electrodes. The gelled electrolyte consisting of a polyacrylamide matrix and phytic acid is shown to promote selective ion diffusion. A synergistic combination consisting of the thermodiffusion effect and redox reactions on the electrode is established in a pre-treated layout. Such TEC affords a high output voltage of 0.4 V, an excellent instantaneous output power density (20.26 mW m-2 K-2 ) and a record-high 2 h output energy density (2451 J m-2 ) under TH = 30 °C with TC = 15 °C, with an ultrahigh Carnot-relative efficiency of 1.12%.

Asymmetric strategy for enhanced performance of flexible electroadhesive clutch.

Flexible electroadhesive clutches with high shear stress and fast response working at low voltage are much desired in wearable electronics and robotic systems. Dielectric materials with opposite charge characteristics could maximize the clutch performance by taking advantages of the boosted electroadhesion between the two contact pads in an asymmetrically structured clutch. In this paper, asymmetrically structured electroadhesive clutches are proposed and reported for the first time. The asymmetric structured clutch exhibits a two-fold increment in the shear force but similar response time by simply reversing the electrode polarity. This work provides a new dimension to realize high-performance electroadhesive clutches based on an asymmetric strategy.

Silencing FOXP2 reverses vemurafenib resistance in BRAFV600E mutant papillary thyroid cancer and melanoma cells.

BACKGROUND: Vemurafenib (VEM) is a commonly used inhibitor of papillary thyroid cancer (PTC) and melanoma with the BRAFV600E mutation; however, acquired resistance is unavoidable. The present study aimed to identify a potential target to reverse resistance. MATERIALS AND METHODS: A VEM-resistant PTC cell line (B-CPAP/VR) was established by gradually increasing the drug concentration, and a VEM-resistant BRAFV600E melanoma cell line (A375/VR) was also established. RNA sequencing and bioinformatics analyses were conducted to identify dysregulated genes and construct a transcription factor (TF) network. The role of a potential TF, forkhead box P2 (FOXP2), verified by qRT-PCR, was selected for further confirmation. RESULTS: The two resistant cell lines were tolerant of VEM and displayed higher migration and colony formation abilities (p < 0.05). RNA sequencing identified 9177 dysregulated genes in the resistant cell lines, and a TF network consisting of 13 TFs and 44 target genes was constructed. Alterations in FOXP2 expression were determined to be consistent between the two VEM-resistant cell lines. Finally, silencing FOXP2 resulted in an increase in drug sensitivity and significant suppression of the migration and colony formation abilities of the two resistant cell lines (p < 0.05). CONCLUSIONS: The present study successfully established two VEM-resistant cell lines and identified a potential target for VEM-resistant PTC or melanoma.

Fast NURBS-based parametric modeling of human calves with high-accuracy for personalized design of graduated compression stockings.

BACKGROUND AND OBJECTIVES: Accurate human body models are increasingly demanded by high-quality human-centered ergonomic applications, especially the design and manufacturing of compressive functional apparels. However, existing parametric models in related works are not capable to accurately describe detailed local shape features of human. METHODS: In this work, a high-accuracy parametric modeling approach for human limb was proposed. 3D Scans of human calves were studied. Key data points of the scanned human calves were identified according to human anatomy, forming a quasi-triangular mesh of feature points. Then, non-uniform rational B-splines (NURBS) method was implemented. Control points were calculated from the key data points, with which the human calf shapes can be reconstructed by the smooth NURBS surface, giving rise to a new parametric model of human calves. Error between the scanned and reconstructed calf shapes were analyzed to verify the effectiveness of this model. RESULTS: Error analysis showed that, this proposed method delivers a high-efficiency and high-accuracy parametric shape modeling approach with averaged error observed as only 0.37% for all the 260 subjects, much less compared to previous relative works (around 5%). For tentative application, customized medical compression stockings were designed based on this model and proved as valid to exert desired gradient compression on the according calf mannequin. CONCLUSIONS: By introducing the non-uniform rational B-splines method, a parametric model capable of characterizing human limbs with high-accuracy was proposed. Using very small amount of data, this model is expected to highly facilitate remote customized design and provide 3D shape references for design of compressive garments. Moreover, the proposed methods can inspire developments of other mixed modeling methods for high-accuracy applications.

Novel oxymagnesite/green rust nanohybrids for selective removal and slow release of phosphate in water.

The new paradigm in wastewater treatment demands to change traditional pollutants removal into resource recovery, especially for non-renewable P resources, effectively recovering phosphate from wastewater and reutilizing it as a nutrient is crucial to P sustainable utilization and P-related pollution control. The nanomaterial-based adsorption technology for P recovery from wastewater is becoming a research hotspot due to its high efficiency and selectivity. Herein, to recover aqueous phosphate, we developed novel oxymagnesite/green rust (OMGR) nanohybrids by a one-pot hydrothermal method. Green rust nanoparticles dispersed on the highly reactive oxymagnesite (MgO2MgCO3) nanosheets could achieve efficient recovery and reuse of P. The volume ratio of water to ethylene glycol played an important role in the preparation of OMGR. The OMGR possessed an excellent selectivity of phosphate removal in the presence of multi-anions and wide pH adaptability in 4.0-10.0. The formation of MgP nanocrystals and the inner-sphere FeOP complexes via ligand exchange contributed to the selective removal of P by OMGR, and the removal capacity reached 141 mg P.g-1. The process of phosphate removal by OMGR was spontaneously endothermic and controlled by the intraparticle and boundary layer diffusion. Most importantly, the high bioavailable P (127 mg.g-1) of P-loaded OMGR had a persistent release behavior regulated by dissolution and diffusion, indicating that the P-loaded OMGR can act as a slow-release P-fertilizer. The findings provide a green and eco-friendly approach to realizing P resource recovery and reuse for phosphate-containing wastewaters.

Gut microbiota is correlated with gastrointestinal adverse events of metformin in patients with type 2 diabetes.

Aim: Gastrointestinal discomfort is the most common adverse event in metformin treatment for type 2 diabetes. The mechanism of action of metformin is associated with gut microbiota. However, the gut microbial community structure related to metformin-induced gastrointestinal adverse events remains unclear. This study aimed to investigate it. Methods: 50 patients with newly diagnosed diabetes were treated with metformin 1500mg/d for 12 weeks. The patients were divided into two groups according to whether gastrointestinal adverse events occurred (group B) or did not occur (group A) after treatment. The fecal bacterial communities and short-chain fatty acids (SCFAs) were sequenced and compared. 70 diabetes mice were randomly divided into 8 groups and treated with metformin (Met), clindamycin (Clin) and/or SCFA, which were the Met+/Clin+, Met+/Clin-, Met-/Clin+, Met-/Clin-, Met+/SCFA+, Met+/SCFA-, Met-/SCFA+ and Met-/SCFA- group. After 4 weeks of metformin treatment, blood glucose, food intake, fecal SCFAs, gut microbiota and gut hormones were measured. Results: Metformin increased the abundance of Phascolarctobacterium, Intestinimonas and Clostridium III. Functional prediction analysis showed that the propanoate metabolism pathway was significantly up-regulated. The concentrations of acetic acid and propanoic acid in feces were significantly increased. The abundance of Clostridium sensu stricto, Streptococcus and Akkermansia induced by metformin in group B was higher than that in group A. The propanoate metabolism pathway and propanoic acid in feces were significantly up-regulated in group B. In the animal experiments, the food intake decreased and glucose control increased in metformin groups compared with those in the control groups. The total GLP-1 level in the Met+/Clin- group was significantly higher than that in the Met-/Clin- group, while there was no statistical difference between the Met-/Clin- and Met+/Clin+ group. The total GLP-1 level in the Met-/SCFA+ group was significantly higher than that in the Met-/SCFA-group, while the levels of total GLP-1 and active GLP-1 in the Met+/SCFA- group and the Met+/SCFA+ group were significantly higher than those in the Met-/SCFA-group. Conclusions: Our data suggest that metformin promotes the secretion of intestinal hormones such as GLP-1 by increasing the abundance of SCFA-producing bacteria, which not only plays an anti-diabetic role, but also may causes gastrointestinal adverse events.

Confirmation of the Absence of Somogyi Effect in Patients with Type 2 Diabetes by Retrospective Continuous Glucose Monitoring Systems.

Background: The Somogyi effect is defined as fasting hyperglycemia secondary to nocturnal hypoglycemia. In past decades, this effect proved to be rare or absent. However, many endocrinologists still believe in this phenomenon in clinical practice. Does the Somogyi effect truly exist? We aimed to answer this question with a study based on a larger sample size. Methods: We collected retrospective CGMs data from 2,600 patients with type 2 diabetes with stable treatment of insulin. Nocturnal hypoglycemia was defined as a CGMs sensor glucose of less than 3.9 mmol/L for at least 15 min between 24:00 and 06:00. Morning fasting glucose was compared between people with nocturnal hypoglycemia and without nocturnal hypoglycemia. Results: Valid CGMs data were obtained on 4,705 of 5,200 nights. Morning fasting glucose was observed lower after nights with nocturnal hypoglycemia compared with nights without hypoglycemia (P < 0.001). 84 cases presented fasting glucose of more than 7 mmol/L after nocturnal glucose of less than 3.9 mmol/L. Only 27 cases presented fasting glucose of more than 7 mmol/L after nocturnal glucose of less than 3.0 mmol/L. Fasting glucose values below 3.9 mmol/l in the morning were associated with a 100% risk of nocturnal hypoglycemia, while fasting glucose values over 9.6 mmol/l in the morning were associated with no risk of nocturnal hypoglycemia. Correlation analysis showed that the nocturnal glucose nadir was significantly correlated with fasting glucose levels (r = 0.613, P < 0.001). Conclusions: Our data provided no support for the existence of the Somogyi effect. If fasting glucose exceeds 9.6 mmol/L, we do not have to worry about asymptomatic nocturnal hypoglycemia in patients with type 2 diabetes.

Synthesis of Polylactic Acid Oligomers for Broad-Spectrum Antimicrobials.

Infectious microbial diseases are a major public health hazard, calling for more innovative antimicrobials. Herein, polylactic acid (PLA) oligomers have been explored and reported as a bio-safe and eco-friendly functional antimicrobial agent against pathogens, such as viruses (H1N1, H3N2, and SARS-CoV-2), bacteria (E. coli, S. aureus, K. pneumoniae, MRSA), and fungi (C. albicans). The PLA oligomers were prepared by direct catalyst-free condensation polymerization of l-lactic acid monomers and characterized by FT-IR and 1H-NMR. The antiviral results demonstrate that PLA oligomers possess robust (inhibiting rate > 99%) and rapid (<20 min) antiviral activity against two pandemic ssRNA viruses, including influenza A virus (IAV) and coronavirus (CoV). Furthermore, the PLA oligomers exhibit high antibacterial activities against both Gram negative (G−) and Gram positive (G+) bacteria. The PLA oligomers also perform efficiently in killing a large amount of C. albicans as high as 105 cfu/mL down to zero at the concentration of 10 mg/mL. Thus, the broad-spectrum antimicrobial activity endowed the PLA oligomers with a promising biocidal option, except antibiotics in a wide range of applications, such as medical textiles, food preservation, water disinfection, and personal hygiene, in light of their unique biodegradability and biocompatibility.

Environmentally Tolerant Ionic Hydrogel with High Power Density for Low-Grade Heat Harvesting.

Harvesting low-grade heat by an ionic hydrogel thermoelectric generator (ITEG) into useful electricity is promising to power flexible electronics. However, the poor environmental tolerance of the ionic hydrogel limits its application. Herein, we demonstrate an ITEG with high thermoelectric properties, as well as excellent capabilities of water retention, freezing resistance, and self-regeneration. The obtained ITEG can maintain the original water content at ambient conditions (302 K, 65% relative humidity (RH)) for 7 days and keep unfreezing at a low temperature (253 K). It can even be self-regenerated and recovered to its original state after a water loss in high-temperature conditions. Furthermore, a high ionic Seebeck coefficient of 11.3 mV K-1 and an impressive power density of 167.90 mW m-2 are achieved under a temperature difference of 20 K. A high power density of 60.00 mW m-2 can also be maintained even at 258 K. After drying and regeneration, ITEG-re could even exhibit a higher ionic Seebeck coefficient of 11.8 mV K-1. Successful lighting of light-emitting diodes (LEDs) and charging of capacitors demonstrate the great potential of ITEG to provide continuous energy supply for powering flexible electronics.

A universal biocompatible coating for enhanced lubrication and bacterial inhibition.

Antibacterial coatings that inhibit bacterial adhesion are essential for many implanted medical devices. A variety of antibacterial strategies, such as repelling or killing bacteria, have been developed, but not yet been completely successful. Here, we develop a universal biocompatible coating for enhanced lubrication and bacterial inhibition. The coating is designed based on mussel-inspired surface-attachable dopamine bases and consists of lubricating zwitterionic polymers poly(2-methacryloxyethyl phosphorylcholine) (MPC) and a bacterial membrane destroying anti-bacteria molecule poly(3-hydroxybutyric acid) (PHB). The coating boasts strong adhesion to surfaces of various materials (such as polydimethylsiloxane (PDMS)/ceramic/316L stainless steel (316L SS); it is biocompatible, and cell/platelet/bacteria repelling, significantly inhibiting bacterial growth. We envision that our strategy represents a universal strategy for surface functionalization of a variety of biomedical devices and implants.

Scalable production of ultrafine polyaniline fibres for tactile organic electrochemical transistors.

The development of continuous conducting polymer fibres is essential for applications ranging from advanced fibrous devices to frontier fabric electronics. The use of continuous conducting polymer fibres requires a small diameter to maximize their electroactive surface, microstructural orientation, and mechanical strength. However, regularly used wet spinning techniques have rarely achieved this goal due primarily to the insufficient slenderization of rapidly solidified conducting polymer molecules in poor solvents. Here we report a good solvent exchange strategy to wet spin the ultrafine polyaniline fibres. The slow diffusion between good solvents distinctly decreases the viscosity of protofibers, which undergo an impressive drawing ratio. The continuously collected polyaniline fibres have a previously unattained diameter below 5 µm, high energy and charge storage capacities, and favorable mechanical performance. We demonstrated an ultrathin all-solid organic electrochemical transistor based on ultrafine polyaniline fibres, which operated as a tactile sensor detecting pressure and friction forces at different levels.

Ionic Hydrogel for Efficient and Scalable Moisture-Electric Generation.

The progress of spontaneous energy generation from ubiquitous moisture is hindered the low output current and intermittent operating voltage of the moisture-electric generators. Herein a novel and efficient ionic hydrogel moisture-electric generator (IHMEG) is developed by rational combination of poly(vinyl alcohol), phytic acid, and glycerol-water binary solvent. Thanks to the synergistic effect of notable moisture-absorption capability and fast ion transport capability in the ionic hydrogel network, a single IHMEG unit of 0.25 cm2 can continuously generate direct-current electricity with a constant open-circuit voltage of ≈0.8 V for over 1000 h, a high short-current density of 0.24 mA cm-2 , and power density of up to 35 µW cm-2 . Of great importance is that large-scale integration of IHMEG units can be readily accomplished to offer a device with voltage up to 210 V, capable of directly driving numerous commercial electronics, including electronic ink screen, metal electrodeposition setup, and light-emitting-diode arrays. Such prominent performance is mainly attributed to the enhanced moisture-liberated proton diffusion proved by experimental observation and theoretical analysis. The ionic hydrogel with high cost-efficiency, easy-to-scaleup fabrication, and high power-output opens a brand-new perspective to develop a green, versatile, and efficient power source for Internet-of-Things and wearable electronics.

Accelerated Degradation of Poly(lactide acid)/Poly(hydroxybutyrate) (PLA/PHB) Yarns/Fabrics by UV and O2 Exposure in South China Seawater.

Marine plastic pollution is emerging as a potential hazard to global ecosystems and human health. Micro-fibers derived from synthetic textiles contribute a considerable proportion of plastic debris. Bio-polymers/bio-plastics have been proposed for the application of apparel products, yet their degradability, fate, durability and related environmental parameters are still elusive and need further exploration. Herein, we report the degradation behavior of poly(lactide acid)/poly(hydroxybutyrate) (PLA/PHB) fabrics, made from PLA/PHB multi-filament yarns, in subtropics marine seawater. The degradation experiments were performed under various parallel conditions including static seawater, aerobic seawater in dark box, aerobic seawater under sunlight, static seawater under ultra-violet light and aerobic seawater under ultra-violet light. Continuous mass loss of PLA/PHB fabrics as the immersion time in the seawater increased was confirmed. The hydrolysis rate of PLA/PHB fabrics accelerated in the presence of UV light and dissolved oxygen in the seawater. Moreover, the tensile strength of the PLA/PHB yarns dropped rapidly by 38.54-68.70% in spite of the mass loss percentage being from 9.57% to 14.48% after 2 weeks' immersion. All the PLA/PHB fabrics after two weeks' immersion exhibited similar ATR-IR spectra. Therefore, the degradability of PLA/PHB fabrics, in the marine surface water under the synergistic destructive effect of seawater, UV and dissolved oxygen, provides a pathway for more sustainable textile fibers and apparel products.