Biomimetic Multiscale Oriented PVA/NRL Hydrogel Enabled Multistimulus Responsive and Smart Shape Memory Actuator.

Shape memory hydrogels provide a worldwide scope for functional soft materials. However, most shape memory hydrogels exhibit poor mechanical properties, leading to low actuation strength, which severely limits their applications in smart biomimetic devices. Herein, a strategy for muscle-inspired shape memory-oriented polyvinyl alcohol (PVA)-natural rubber latex (NRL) hydrogel (OPNH) with multiscale oriented structure is demonstrated. The shape memory function comes from the stretch-induced crystallization of natural rubber (NR), while PVA forms strong hydrogen bonding interactions with proteins and phospholipids on the surface of NRL particles. Meanwhile, the reconfigurable interactions of PVA and NR produce a multiscale-oriented structure during stretch-drying, improving the mechanical and shape memory properties. The resultant OPNH shows excellent interfacial compatibility, exhibiting outstanding mechanical performance (3.2 MPa), high shape fixity (≈80%) and shape recovery ratio (≈92%), high actuation strength (206 kPa), working capacity (105 kJ m- 3), extremely short response time (≈2 s), low response temperature (28 °C) and smart thermal responsiveness. It can even maintain muscle-like working capacity when lifting a load equivalent to 372 times its weight, providing a new class shape memory material for the application in smart biomimetic muscles and multistimulus responsive devices.

[Investigation of the Biosafety of Commercially Available Natural Rubber Latex and Synthetic Polyurethane Condom Materials]. / å¸‚å”®å¤©ç„¶æ©¡èƒ¶èƒ¶ä¹³å’Œäººå·¥åˆæˆèšæ°¨é ¯æè´¨é¿å­•å¥—çš„ç”Ÿç‰©å®‰å ¨æ€§ç ”ç©¶.

Objective: To investigate the biological safety of commercially available natural rubber latex and synthetic polyurethane condoms. Methods: Natural rubber latex condom brands of A1 and A2 and polyurethane condom brands of B1 and B2 were purchased from large chain pharmacies in Chengdu, with three packages randomly selected for each brand. The study assessed the toxic effects of condom extracts on L-929 mouse fibroblasts according to GB/T standards. Gross observation and histopathological evaluation were conducted to assess the irritation reactions of condoms on the vagina and penis of rabbits (3 rabbits were used for each brand), as well as their sensitization effects on guinea pig skin. Additionally, the impact of continuous perfusion of condom extracts of the vaginas of SD rats for 30 days on their reproductive systems was evaluated, following GB/T standards (5 rats were used for each brand). Results: Extracts from natural rubber latex condom brands A1 and A2, at concentrations of 100% and 50%, exhibited significant cytotoxicity, with optical density (OD) values being significantly lower than those of the blank control group and the polyurethane condom brands B1 and B2 (P<0.01). There was no significant difference in cell morphology and OD values between the extracts of B1 and B2 and the blank control group (P>0.05). Vaginal congestion was found in 3 rabbits from A1 group and 1 rabbit from the A2 group, while no obvious congestion was noted in rabbits from the B1 and the B2 groups. Histopathological examination showed scattered inflammatory cell infiltration in the vaginal tissue of 3 rabbits from the A1 group and 2 rabbits from the A2 group, and slight congestion in the blood vessels of the lamina propria. No obvious pathological changes were observed in the vaginal tissue of polyurethane brand rabbits. Two rabbits from the A1 group and 1 rabbit from the A2 group showed transient and mild erythema on the penis during the experiment. Histopathological examination showed that 1 rabbit from A1 group had small foci of pericapillary lymphocytes in the dermis of the penis, while no significant pathological changes were observed in the penile tissue of A2, B1, and B2 groups. After 30 days of continuous vaginal perfusion with condom extract, 3 rats in A1 group and 2 rats in the A2 group had uterine congestion, with the degree of congestion being lower in the A2 group. No significant congestion or pathological changes were observed in the vaginal and penile tissues of rabbits, or in the uterine tissues of rats from the polyurethane groups. None of the 4 groups of guinea pigs showed significant skin allergic reactions to the condom extracts. Conclusion: Significant differences in biosafety exist among condoms of various materials and brands. To ensure product safety, it is crucial to strengthen quality control and regulatory oversight after condoms become commercially available.

Rod-like Cellulose Regenerated by Bottom-Up Assembly in Natural Rubber Latex and Its Reinforcement.

As a renewable biomass material, nano-cellulose has been investigated as a reinforcing filler in rubber composites but has seen little success because of its strong inclination towards aggregating. Here, a bottom-up self-assembly approach was proposed by regenerating cellulose crystals from a mixture of cellulose solution and natural rubber (NR) latex. Different co-coagulants of both cellulose solution and natural rubber latex were added to break the dissolution equilibrium and in-situ regenerate cellulose in the NR matrix. The SEM images showed that the sizes and morphologies of regenerated cellulose (RC) varied greatly with the addition of different co-coagulants. Only when a 5 wt% acetic acid aqueous solution was used, the RC particles showed an ideal rod-like structure with small sizes of about 100 nm in diameter and 1.0 µm in length. The tensile test showed that rod-like RC (RRC)-endowed NR vulcanizates with pronounced reinforcement had a drastic upturn in stress after stretching to 200% strain. The results of XRD and the Mullins effect showed that this drastic upturn in stress was mainly attributed to the formation of rigid RRC-RRC networks during stretching instead of the strain-induced crystallization of NR. This bottom-up approach provided a simple way to ensure the effective utilization of cellulosic materials in the rubber industry.

Characteristics of hand eczema in final-year apprentice nurses during the COVID-19 pandemic.

BACKGROUND: Apprentice nurses are considered at high risk to developing occupational skin diseases. OBJECTIVES: This study assessed the frequency and origin of hand eczema, and work-related risk factors in apprentice nurses. METHODS: The study involved 240 final-year apprentice nurses (females 75%, median age 19 years) from vocational schools in Zagreb, Croatia. The study was performed in 2020/2021 and included a questionnaire and clinical examination by means of the Osnabrück Hand Eczema Severity Index (OHSI). Skin prick test (SPT) with natural rubber latex (NRL) allergen, and patch test with the basic series of allergens, and disinfectants, were performed in 42 apprentice nurses with hand eczema that lasted more than 3 months. RESULTS: Clinically observed and self-reported hand eczema were found in 49% and 46% of apprentice nurses, respectively. Those with observed changes were older and reported more days per month spent on practical work than those with healthy skin (P = .001). Median OHSI was 4 (interquartile range 2-6). There were no positive SPTs to latex, and 11 (26%) apprentice nurses had positive patch test reactions to one or more tested allergens, mostly nickel. CONCLUSIONS: Hand eczema was common in final-year apprentice nurses during the COVID-19 pandemic. It was mostly of irritative origin, associated with the duration of practical training, confirming cumulative effect of hazards on skin barrier.

Tailored Sublingual Immunotherapy in a Monosensitized Child with Natural Rubber Latex Allergy.

Adverse reactions to natural rubber latex (NRL) represent a group of clinical manifestations that include non-allergic reactions and immediate-type or delayed-type allergic reactions. NRL sublingual immunotherapy (SLIT) has been demonstrated to be an effective and safe practice for latex clinical manifestations with good patient tolerance. A pediatric case of NRL allergy managed with an effective tailored SLIT is described. This case is compelling because the girl, who did not have an atopic background, suffered from NRL allergy with high reactivity and unique monosensitization. To the best of our knowledge, this is the first case with this characteristic described to date. Moreover, the SLIT follow-up time reported was unusually long, extending from childhood to adulthood. The case described highlights several problems of real-life management, and it demonstrates how the pediatric allergist plays a key role in the management of all these issues in order to succeed in guiding the patient through the immunotherapy process with a personalized approach, in line with the precision medicine principles. However, further long-term clinical studies are needed to better define the natural history of NRL allergy and find new potential biomarkers of response to NRL immunotherapy.

Chitosan and Natural Rubber Latex Biocomposite Prepared by Incorporating Negatively Charged Chitosan Dispersion.

Generally, natural rubber/chitosan (NR/CT) biocomposites could be prepared by either mixing natural rubber latex (NRL) with CT acid solution or mixing dry NR with CT powder on mixing equipment. In the present work, a new mixing method has been proposed and properties of the obtained NR/CT biocomposites are investigated. CT particles were prepared to have a negative charge that could be dispersed in water by using a ball mill before mixing with NRL. The effects of CT loading varied from 0 to 8 phr on latex properties and physical properties of NR/CT biocomposite films were focused. The results showed that the viscosity of NRL increased with increasing CT loading. With increasing CT loading from 0 to 8 phr, 300% modulus of the NR/CT biocomposite film increased, whereas the opposite trend was found for elongation at break. Additionally, the presence of CT in the biocomposite resulted in an increased elastic modulus (E') in conjunction with enhanced antibacterial activity against Staphylococcus aureus (S. aureus).

Considering the switch to a latex-free glove policy to safeguard staff and patients.

While it is difficult to imagine that before the late 1800s, surgeons in the theatre environment operated on patients without gloves, gloves are now a clinical necessity. Their use has risen exponentially over the last 30 years, along with concerns over staff and patient allergy and sensitivity to the natural rubber latex proteins used in their manufacture. Having used latex gloves for the better part of 35 years, the author recently evaluated a latex-free alternative. In this article, which presents a rationale for the introduction of a latex-free glove policy across NHS departments and trusts, particularly in theatre settings, the author presents his experience, together with cases from four other surgeons, as well as evidence from the literature regarding potential clinical outcomes, quality of life and cost-effectiveness associated with latex-free gloves.

Profile Shift in Latex Sensitization over the Last 20 Years.

BACKGROUND: Natural rubber latex (NRL) allergy is commonly diagnosed according to medical history, skin allergy tests, and serological analyses. However, skin tests are increasingly being abandoned because of (i) their time-consuming nature, (ii) latex preparations for skin tests being not commercially available, and (iii) the use of in-house prepared test solutions is becoming ever more difficult due to increasing regulatory hurdles. In this light, we have evaluated differences in the profiles of current and former patients with suspected latex allergy. METHODS: Sera of skin test-positive patients from a historic cohort (1995-2001, n = 149 patients) and currently (2014-2015, n = 48 patients) were simultaneously analyzed for specific IgE to latex by ImmunoCAP. If the serological screening was positive (≥0.35 kU/L), component-resolved diagnostics including profilins and cross-reactive carbohydrate determinants (CCDs) were performed. RESULTS: In contrast to 88% (131/149) of the skin test-positive patients from the 1990s, only 51.1% (24/47) of the current cohort were found positive for specific IgE to latex. While 48.3% (72/149) of the patients had a convincing positive history in the 1990s, current skin test-positive patients rarely reported a relevant medical history (8.5%, 4/47). Specific IgE levels to latex were significantly higher in former patients with suspected latex allergy (p < 0.001) than in former sensitized individuals without allergy. However, this significant difference was lost in current allergic and sensitized patients with positive skin tests. CONCLUSION: Sensitization profiles in patients with latex allergy have changed significantly over the last 2 decades. Discrimination between NRL sensitization and clinical allergy remains a diagnostic challenge. Our data highlight the need for a combination of all 3 criteria, i.e., patient history, skin test, and analysis of specific IgE, for a correct diagnosis of latex allergy.

Novel polymeric dressing to the treatment of infected chronic wound.

Natural rubber latex (NRL) is a natural polymer which has arisen large interest in the biomedical field, mostly, due to its ability to facilitate angiogenesis and therefore, tissue repair. Moxifloxacin (MXF) is a broad-spectrum antibiotic orally administrated. Considering the biological properties of the NRL and its ability to deliver a wide range of compounds, the present study aimed to develop a novel device for infected chronic wound treatment. MXF-loaded NRL was obtained by a casting method. The results demonstrated that the incorporation of MXF in NRL did not promote any molecular interaction, preserving the integrity of the compounds. The mechanical properties of the biomaterial did not show any significant change, indicating enough elasticity for dermal application. The microbiological assays confirmed the ability of the polymer to deliver the drug without influencing its pharmacological properties. Moreover, it has expressed activity against major bacterial strains presented in wound infections. Finally, the biomaterial shown biocompatibility from the in vitro study. Thus, the present work has shown that MXF-loaded NRL membrane is a promising biomaterial to infected wound treatment.

Evaluation of peptides release using a natural rubber latex biomembrane as a carrier.

The biomembrane natural (NRL-Natural Rubber Latex), manipulated from the latex obtained from the rubber tree Hevea brasiliensis, has shown great potential for application in biomedicine and biomaterials. Reflecting the biocompatibility and low bounce rate of this material, NRL has been used as a physical barrier to infectious agents and for the controlled release of drugs and extracts. The aim of the present study was to evaluate the incorporation and release of peptides using a latex biomembrane carrier. After incorporation, the release of material from the membrane was observed using spectrophotometry. Analyses using HPLC and mass spectroscopy did not confirm the release of the antimicrobial peptide [W6]Hylin a1 after 24 h. In addition, analysis of the release solution showed new compounds, indicating the degradation of the peptide by enzymes contained in the latex. Additionally, the release of a peptide with a shorter sequence (Ac-WAAAA) was evaluated, and degradation was not observed. These results showed that the use of NRL as solid matrices as delivery systems of peptide are sequence dependent and could to be evaluated for each sequence.

Addressing Molecular Diagnosis of Occupational Allergies.

PURPOSE OF REVIEW: Numerous clinically relevant allergenic molecules enhance the performance of specific (s) IgE tests and improve the specificity of allergy diagnosis. This review aimed to summarize our current knowledge of the high-molecular-weight allergens involved in the development of occupational asthma and rhinitis and to critically analyze the contribution of component-resolved diagnosis in the management of these conditions. RECENT FINDINGS: There is a lack of standardization and validation for most available extracts of occupational agents, and assessment of sIgE reactivity to occupational allergen components has been poorly investigated, with the notable exception of natural rubber latex (NRL) and wheat flour. In the case of NRL, the application of recombinant single allergens and amplification of natural extracts with stable recombinant allergens improved the test sensitivity. IgE-sensitization profile in patients with baker's asthma showed great interindividual variation, and extract-based diagnostic is still recommended. For other occupational allergens, it remains necessary to evaluate the relevance of single allergen molecules for the sensitization induced by occupational exposure. Progress has been made to characterize occupational allergens especially NRL and wheat, although there is still an unmet need to increase the knowledge of occupational allergens, to include standardized tools into routine diagnostic, and to evaluate their usefulness in clinical practice.

Occupational contact urticaria and protein contact dermatitis: causes and concomitant airway diseases.

BACKGROUND: Contact urticaria (CU) and protein contact dermatitis (PCD) are mainly induced by an immediate, IgE-mediated immunological mechanism. Immediate sensitization is also linked to asthma and/or allergic rhinitis. OBJECTIVES: To report causes of work-induced CU and PCD, and to evaluate the occurrence of concomitant airway diseases. METHODS: We retrospectively reviewed the patient files of cases diagnosed with CU or PCD at the Finnish Institute of Occupational Health during 1995-2011. We obtained data on occupation, exposures, clinical and immunological test results, and diagnosed occupational skin and respiratory diseases. RESULTS: Altogether, 291 cases of occupational CU or PCD were diagnosed during the study period. The most common causes were flour, cow dander, natural rubber latex and acid anhydrides. Concomitant occupational asthma caused by the same agent as the skin disease was detected in 60 patients (21%), and occupational rhinitis was detected in 111 patients (38%). CONCLUSIONS: Almost half of the patients (46%) with occupational CU and PCD had concomitant occupational airway disease. Patients with CU/PCD should always be asked about respiratory symptoms, and preventive measures at the workplace should include protection of both the skin and the airways.

Protection efficacy of gloves against components of the solvent in a sprayed isocyanate coating utilizing a reciprocating permeation panel.

OBJECTIVES: Determine protection effectiveness of 5-mil natural rubber latex (0.13-mm), 5-mil nitrile rubber (0.13-mm), and 13-mil butyl rubber (0.33-mm) glove materials against solvents present in a commonly used automotive clear coat formulation using a novel permeation panel. The latex and nitrile gloves were the type commonly used by local autobody spray painters. METHODS: Glove materials were tested by spraying an automotive clear coat onto an automated reciprocating permeation panel (permeation panel II). Temperature, relative humidity, and spray conditions were controlled to optimize clear coat loading homogeneity as evaluated by gravimetric analysis. Solvent permeation was measured using charcoal cloth analyzed by the National Institute for Occupational Safety and Health 1501 method. RESULTS: Natural rubber latex allowed 3-5 times the permeation of solvents relative to nitrile rubber for all 10 solvents evaluated: ethyl benzene, 2-heptanone, 1-methoxy-2-propyl acetate, o-xylene, m-xylene, p-xylene, n-butyl acetate, methyl isobutyl ketone, petroleum distillates, and toluene. There is a distinct behavior in solvent permeation before and after the coating dry time. Solvent permeation increased steadily before coating dry time and remained fairly constant after coating dry time. Butyl was not permeated by any of the solvents under the conditions tested. CONCLUSIONS: Commonly used 5-mil thick (0.13-mm) latex and nitrile gloves were ineffective barriers to solvents found in a commonly used clear coat formulation. Conversely, 13-mil (0.33-mm) butyl gloves were found to be protective against all solvents in the clear coat formulation.

Decrease in the rate of sensitization and clinical allergy to natural rubber latex.

BACKGROUND: In the 1980s, a striking increase in natural rubber latex (NRL) allergy was seen. Since then, many measures have been taken to prevent NRL allergy. OBJECTIVES: To investigate changes in the prevalence of NRL sensitization/clinical NRL allergy over time from 2002 to 2013. METHODS: All patients prick tested for NRL at the Department of Dermatology and Allergy Centre, Odense University Hospital were included in this study (n = 8580). In NRL-sensitized patients, the clinical relevance was evaluated for NRL. Furthermore, concomitant positive prick test results for birch pollen were recorded, together with food-related symptoms and sensitization in a subgroup of patients. RESULTS: The prevalence of NRL sensitization declined from 6.1% in 2002-2005 to 1.9% in 2006-2009, and then to 1.2% in 2010-2013 (p < 0.0001). The prevalence of clinical NRL allergy declined from 1.3% in 2002-2005 to 0.5-0.6% in 2006-2013 (p < 0.004). Among the NRL-sensitized patients, 64% had a concomitant positive prick test reaction to birch pollen, and 52% had a history of reaction to oral intake of related fruits or vegetables. CONCLUSION: Our study showed a statistically significant decline in the number of patients sensitized/clinically allergic to NRL. Many of the NRL-sensitized patients without clinical allergy to NRL had concomitant birch pollen sensitization, and reported food-related symptoms.

Anaphylactic reaction after ongoing exposure to hair glue: a novel case report.

BACKGROUND: Latex allergy is thought to be present in up to 6.5% of the general population, and can be much higher among those with chronic exposure. It is, however, uncommonly associated with severe anaphylactic reactions. Hair-care practices, such as the application of a hair weave, are a potential cause of latex-related anaphylaxis because the adhesives often contain natural rubber latex. CASE REPORT: We report the first case in the emergency medicine literature of successful treatment of a patient with airway compromise secondary to hair glue exposure. This case involved a 29-year-old woman who presented to the emergency department with severe angioedema and airway compromise. The patient had recently had an adhesive substance applied to her scalp for a hair weave placement. The patient did respond initially to antihistamine and alpha-adrenergic medication, however, because the allergen could not be removed, she relapsed, was subsequently intubated, and admitted to the intensive care unit. The latex-containing hair glue was removed over a period of several hours using an oil-based hair-conditioning product. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This unique and potentially lethal situation required innovative management. Successful resolution of this case required a high degree of cultural literacy leading to the correct diagnosis and treatment, and utilization of resources outside of the health care field. Clinicians treating patients in areas where similar hair-care practices are prevalent should be aware of this pathology, and consider similar management strategies.

Transdermal nicotine mixed natural rubber-hydroxypropylmethylcellulose film forming systems for smoking cessation: in vitro evaluations.

Novel film forming polymeric dispersions for transdermal nicotine delivery were prepared from deproteinized natural rubber latex (DNRL) blended with hydroxypropylmethylcellulose (HPMC) and dibutyl phthalate (DBP) or glycerin (GLY) as plasticizer. The preliminary molecular compatibility of ingredients was observed by Fourier transform infrared spectroscopy, differential scanning calorimetry and X-ray diffractometry characterizations. All film forming polymeric dispersions were elegant in appearance and smooth in texture without agglomeration. Their pH was 7-8. In addition, their viscosity and spreadability showed good characteristics depended on HPMC and plasticizers blended. The transparent in situ dry films with good strength and elasticity were also confirmed by peeling-off. The nicotine release from them revealed an initial fast release that was similar to the release from a concentrated nicotine solution, and followed by slow release pattern from the in situ films. GLY blended formulation produced a higher amount of nicotine permeation through the in vitro pig skin than DBP blends. Ethanol mixing also enhanced nicotine permeation, but it affected the integrity of in situ films. The nicotine release and skin permeation kinetics were by a diffusion mechanism that was confirmed by the Higuchi's model. These formulations were safe without producing any severe skin irritation. However, for the stability they needed to be stored at 4 °C in tightly sealed containers.

Testing of glove efficacy against sprayed isocyanate coatings utilizing a reciprocating permeation panel.

OBJECTIVES: Modify a permeation panel to evaluate dermal protective clothing for resistance to sprayed coatings with minimal variability in spray paint loading across the test panel. Determine isocyanate protection effectiveness of natural rubber latex (5 mil or 0.13mm), nitrile rubber (5 mil or 0.13mm), and butyl rubber (13 mil or 0.33mm) glove materials against a commonly used automotive clear coat formulation. The latex and nitrile gloves were the type used by the local autobody spray painters. METHODS: Glove materials were tested by spraying paint onto an automated reciprocating permeation panel (permeation panel II). Temperature, relative humidity, and spray conditions were controlled to optimize paint loading homogeneity as evaluated by gravimetric analysis. Isocyanate permeation was measured using 1-(2-pyridyl)-piperazine-coated fiber-glass filters analyzed by a modified version of the OSHA 42/PV2034 methods. RESULTS: Latex exhibited a higher permeation rate compared with nitrile for isocyanates (1,6-hexamethylene diisocyanate (HDI) and isophorone diisocyanate monomers) and both materials presented permeation at all of the time points suggesting a fast isocyanate breakthrough. Butyl material exhibited no permeation or breakthrough for isocyanates under the tested conditions. The spray application at 69±8°F was optimally homogeneous at 45±0.5mg weight of dry clear coat per 5cm(2). CONCLUSIONS: The permeation panel II is a reliable method to assess dermal protective clothing performance against polymerizing coatings. Commonly used 5-mil (0.13-mm) latex and nitrile gloves were determined to be ineffective barriers against the isocyanates found in a commonly used clear-coat formulation while butyl gloves were protective.

Wormwood-infused porous-CaCO3 for synthesizing antibacterial natural rubber latex.

Wormwood leaf is a traditional Chinese herbal medicine with a high medicinal value and long application history and its essential oil is a high-purity plant oil extracted from Wormwood leaf. Pharmacological research reveals that Wormwood leaf and Wormwood essential oil are a broad-spectrum antibacterial and antiviral drug, which can inhibit and kill many bacteria and viruses. We loaded wormwood extract on porous calcium carbonate (Porous-CaCO3) and introduced it and Wormwood essential oil into Natural rubber latex (NRL), thus synthesizing NRL composites with excellent vitro and in vivo antibacterial effect, cell compatibility and mechanical properties. This NRL material can delay the light aging and thermal oxidation of some mechanical properties, which provides a broader avenue for its commercialization.

Rapid formation of carbon nanotubes-natural rubber films cured with glutaraldehyde for reducing percolation threshold concentration.

Carbon nanotubes (CNTs) filled natural rubber (NR) composites with various CNT contents at 0, 1, 2, 3, 4 and 5 phr were prepared by latex mixing method using glutaraldehyde as curing agent. This work aims to improve the electrical and mechanical properties of CNT filled NR vulcanizates. The CNT dispersion of NR composites was clarified using dispersion grader, optical microscopy and scanning electron microscopy. The electrical properties of NR composites in the existing of CNT networks were studied by following the well-known percolation theory. It was observed that the NR composites exhibited low percolation threshold at 0.98 phr of CNT. Moreover, a three-dimensional network formation of CNT in the NR composites was observed and it is indicated by the t-value of 1.67. The mechanical properties of NR composites in terms of modulus, tensile strength and hardness properties were increased upon the addition of CNT to the optimum mechanical properties at 1 phr of CNT. Therefore, the present work is found the novelty of the study that the conductive rubber latex film can be produced using GA as low-temperature curing agent which enhanced good electrical properties. Moreover, this work is found to be beneficial in case of conductive rubber latex film that requires high modulus at low strain. The additional advantage of this system is the curing process occurs at low-temperature using GA and it can be easily processed.

Highly Stable Flexible Organic Electrochemical Transistors with Natural Rubber Latex Additives.

Organic electrochemical transistors (OECTs) have attracted considerable interest in the context of wearable and implantable biosensors due to their remarkable signal amplification combined with seamless integration into biological systems. These properties underlie OECTs' potential utility across a range of bioelectronic applications. One of the main challenges to their practical applications is the mechanical limitation of PEDOT:PSS, the most typical conductive polymer used as a channel layer, when the OECTs are applied to implantable and stretchable bioelectronics. In this work, we address this critical issue by employing natural rubber latex (NRL) as an additive in PEDOT:PSS to improve flexibility and stretchability of the OECT channels. Although the inclusion of NRL leads to a decrease in transconductance, mainly due to a reduced carrier mobility from 0.3 to 0.1 cm2/V·s, the OECTs maintain satisfactory transconductance, exceeding 5 mS. Furthermore, it is demonstrated that the OECTs exhibit excellent mechanical stability while maintaining their performance even after 100 repetitive bending cycles. This work, therefore, suggests that the NRL/PEDOT:PSS composite film can be deployed for wearable/implantable applications, where high mechanical stability is needed. This finding opens up new avenues for practical use of OECTs in more robust and versatile wearable and implantable biosensors.