Endometrial Pipelle Biopsy Computer-Aided Diagnosis: A Feasibility Study.

Endometrial biopsies are important in the diagnostic workup of women who present with abnormal uterine bleeding or hereditary risk of endometrial cancer. In general, approximately 10% of all endometrial biopsies demonstrate endometrial (pre)malignancy that requires specific treatment. As the diagnostic evaluation of mostly benign cases results in a substantial workload for pathologists, artificial intelligence (AI)-assisted preselection of biopsies could optimize the workflow. This study aimed to assess the feasibility of AI-assisted diagnosis for endometrial biopsies (endometrial Pipelle biopsy computer-aided diagnosis), trained on daily-practice whole-slide images instead of highly selected images. Endometrial biopsies were classified into 6 clinically relevant categories defined as follows: nonrepresentative, normal, nonneoplastic, hyperplasia without atypia, hyperplasia with atypia, and malignant. The agreement among 15 pathologists, within these classifications, was evaluated in 91 endometrial biopsies. Next, an algorithm (trained on a total of 2819 endometrial biopsies) rated the same 91 cases, and we compared its performance using the pathologist's classification as the reference standard. The interrater reliability among pathologists was moderate with a mean Cohen's kappa of 0.51, whereas for a binary classification into benign vs (pre)malignant, the agreement was substantial with a mean Cohen's kappa of 0.66. The AI algorithm performed slightly worse for the 6 categories with a moderate Cohen's kappa of 0.43 but was comparable for the binary classification with a substantial Cohen's kappa of 0.65. AI-assisted diagnosis of endometrial biopsies was demonstrated to be feasible in discriminating between benign and (pre)malignant endometrial tissues, even when trained on unselected cases. Endometrial premalignancies remain challenging for both pathologists and AI algorithms. Future steps to improve reliability of the diagnosis are needed to achieve a more refined AI-assisted diagnostic solution for endometrial biopsies that covers both premalignant and malignant diagnoses.

How deep is too deep? Assessing myometrial invasion as a predictor of distant recurrence in stage I endometrioid endometrial cancer.

OBJECTIVES: The goal of this study was to evaluate the depth of myometrial invasion as a predictor of distant recurrence in patients with node-negative stage IB endometrioid endometrial cancer. METHODS: A retrospective multicenter study, including surgically staged endometrial cancer patients at Mayo Clinic, Rochester (MN, USA) between January 1999 and December 2017, and Fondazione Policlinico Universitario A. Gemelli (Rome, Italy) between March 2002 and March 2017, was conducted. Patients without lymph node assessment were excluded. The follow-up was restricted to the first 5 years following surgery. Recurrence-free survival was estimated using the Kaplan-Meier method. Cox proportional hazards models were fit to evaluate the association of clinical and pathologic characteristics with the risk of recurrence. RESULTS: Of 386 patients, the mean (SD) depth of myometrial invasion was 70.4 (13.2)%. We identified 51 recurrences (14 isolated vaginal, 37 non-vaginal); the median follow-up of the remaining patients was 4.5 (IQR 2.3-7.0) years. At univariate analysis, the risk of non-vaginal recurrence increased by 64% (95% CI 1.28 to 2.12) for every 10-unit increase in the depth of myometrial invasion. International Federation of Gynecology and Obstetrics (FIGO) grade and myometrial invasion were independent predictors of non-vaginal recurrence. The 5-year non-vaginal recurrence-free survival was 95.2% (95% CI 92.0% to 98.6%), 84.0% (95% CI 76.6% to 92.1%), and 67.1% (95% CI 54.2% to 83.0%) for subsets of patients with myometrial invasion <71% (n=207), myometrial invasion ≥71% and grade 1-2 (n=132), and myometrial invasion ≥71% and grade 3 (n=47), respectively. A total of 256 (66.3%) patients received either vaginal brachytherapy only or no adjuvant therapy. Patients who received adjuvant chemotherapy, regardless of receipt of external beam radiotherapy or vaginal brachytherapy, had an approximately 70% lower risk of any recurrence (HR adjusted for age, grade, myometrial invasion 0.31, 95% CI 0.12 to 0.85) and of non-vaginal recurrence (adjusted HR 0.32, 95% CI 0.10 to 0.99). CONCLUSION: The invasion of the outer third of the myometrium and histologic grade were found to be independent predictors of distant recurrence among patients with endometrioid, node-negative stage IB endometrial cancer. Future studies should investigate if systemic adjuvant therapy for patients with myometrial invasion of the outer third would improve outcomes.

Incidence of sentinel lymph node metastases in apparent early-stage endometrial cancer: a multicenter observational study.

OBJECTIVE: Ultrastaging is accurate in detecting nodal metastases, but increases costs and may not be necessary in certain low-risk subgroups. In this study we examined the risk of nodal involvement detected by sentinel lymph node (SLN) biopsy in a large population of apparent early-stage endometrial cancer and stratified by histopathologic characteristics. Furthermore, we aimed to identify a subgroup in which ultrastaging may be omitted. METHODS: We retrospectively included patients who underwent SLN (with bilateral mapping and no empty nodal packets on final pathology) ± systematic lymphadenectomy for apparent early-stage endometrial cancer at two referral cancer centers. Lymph node status was determined by SLN only, regardless of non-SLN findings. The incidence of macrometastasis, micrometastasis, and isolated tumor cells (ITC) was measured in the overall population and after stratification by histotype (endometrioid vs serous), myometrial invasion (none, <50%, ≥50%), and grade (G1, G2, G3). RESULTS: Bilateral SLN mapping was accomplished in 1570 patients: 1359 endometrioid and 211 non-endometrioid, of which 117 were serous. The incidence of macrometastasis, micrometastasis, and ITC was 3.8%, 3.4%, and 4.8%, respectively. In patients with endometrioid histology (n=1359) there were 2.9% macrometastases, 3.2% micrometastases, and 5.3% ITC. No macro/micrometastases and only one ITC were found in a subset of 274 patients with low-grade (G1-G2) endometrioid endometrial cancer without myometrial invasion (all <1%). The incidence of micro/macrometastasis was higher, 2.8%, in 708 patients with low-grade endometrioid endometrial cancer invading <50% of the myometrium. In patients with serous histology (n=117), the incidence of macrometastases, micrometastasis, and ITC was 11.1%, 6.0%, and 1.7%, respectively. For serous carcinoma without myometrial invasion (n=36), two patients had micrometastases for an incidence of 5.6%. CONCLUSIONS: Ultrastaging may be safely omitted in patients with low-grade endometrioid endometrial cancer without myometrial invasion. No other subgroups with a risk of nodal metastasis of less than 1% have been identified.

Impact of molecular classification on recurrence risk in endometrial cancer patients with lymph node metastasis: multicenter retrospective study.

OBJECTIVE: To assess the distribution of molecular classes and their impact on the risk of recurrence in endometrial cancer patients with lymph node metastasis at the time of primary surgery. METHODS: Endometrial cancer patients with lymph node micrometastasis or macrometastasis (International Federation of Gynecology and Obstetrics (FIGO) 2009 stage IIIC) after surgical staging at five referral centers worldwide from October 2013 to September 2022 who underwent molecular classification were identified. Endometrial cancers were categorized into four molecular classes: POLE mutated, mismatch repair deficient, p53 abnormal, and no specific molecular profile. Survival analyses using Kaplan-Meier and Cox models (univariate and multivariate) were conducted to evaluate the relationship between molecular class and 5-year recurrence free survival. RESULTS: 131 patients were included: 55 (42.0%) no specific molecular profile, 46 (35.1%) mismatch repair deficient, 1 (0.8%) POLE mutated, and 29 (22.1%) p53 abnormal. During a 5 year follow-up period, 50 (38.2%) patients experienced a recurrence with a median time of 1.2 years (interquartile range (IQR) 0.5-1.8). Median follow-up for the remaining 81 patients was 3.1 years (IQR 1.3-4.5). Survival analysis revealed a significant difference in recurrence-free survival between no specific molecular profile, mismatch repair deficient, and p53 abnormal classes (log rank p<0.01). In a model adjusted for type of lymph node metastasis and tumor grade, the molecular class did not retain significance (p=0.13), while in a model adjusted for type of lymph node metastasis and adjuvant therapy, the molecular class retained significance (p<0.01). CONCLUSION: Among patients with stage IIIC endometrial cancer, POLE mutated tumors exhibited an extremely low prevalence, with no specific molecular profile emerging as the largest molecular subgroup. Despite the significant difference in recurrence-free survival between molecular classes, conventional histopathologic parameters retained crucial prognostic value. Our findings highlight the necessity of integrating molecular classes with pathological characteristics, rather than considering them in isolation as crucial prognostic factors in stage IIIC endometrial cancer.

Immune response to COVID-19 vaccines among people living with human T-cell lymphotropic virus type 1 infection: a retrospective cohort study from Iran.

The effectiveness of COVID-19 vaccination is still unclear in individuals with underlying diseases such as HTLV-1 infection. This retrospective cohort study aimed to evaluate the humoral response of COVID-19 vaccines among people living with HTLV-1 (PLHTLV) in northeastern Iran. From December 2021 to October 2022, eighty-six HTLV-1+ subjects (50 males and 36 females; 47.7 ± 11.2 years) and 90 HTLV-1 seronegative individuals (age- and sex-matched convenient samples) were enrolled. The humoral immune response was evaluated by measuring different COVID-19 Abs in serum samples at least 28 days after receiving 2nd or 3rd doses of COVID-19 vaccines. Throughout all three rounds of immunization, Sinopharm was the most commonly used COVID-19 vaccine across all three immunization rounds. Compared to the HTLV-1- group, a significantly lower frequency of all four Abs activity was observed among PLHTLV:anti-nucleocapsid (66.3% vs 86.7%, p = 0·001), anti-spike (91.9% vs 98.9%, p = 0·027), RBD (90.7% vs 97.8%, p = 0·043), and neutralizing Abs (75.6% vs 95.5%, p < 0·001). Also, the frequency of all Abs in 28 patients with HAM/TSP was higher than that of 58 asymptomatic carriers, although this difference was statistically significant only in the case of anti-spike Abs (p = 0.002). Notably, PLHTLV-vaccinated against COVID-19 demonstrated significantly lower antibody activities, indicating a reduced humoral immune response to COVID-19 vaccines.

Mesonephric Adenomyofibroma: A Biphasic Vaginal Mass of Mesonephric Type With Molecular Analysis: A Case Report of a Rare Entity.

Mesonephric neoplasms of the lower female genital tract are rare. To date, there are scarce reports of benign biphasic vaginal mesonephric lesions, and none have included immunohistochemical and/or molecular analysis. A biphasic neoplasm of mesonephric-type was incidentally identified in the vaginal submucosal tissue of a 55-yr-old woman who underwent a right salpingo-oophorectomy for an ovarian cyst. The well-circumscribed, 5 mm nodule exhibited white-tan, firm homogenous cut surfaces. Microscopic examination showed a lobular arrangement of glands with columnar to the cuboidal epithelium and intraluminal eosinophilic secretions, embedded within a myofibromatous stroma. Cytologic atypia and mitotic activity were absent. Immunohistochemical staining for PAX8 and GATA3 demonstrated diffuse expression in the glandular epithelium, CD10 exhibited a patchy luminal expression pattern, while TTF1, ER, PR, p16, and NKX3.1 were negative. Desmin highlighted a subset of the stromal cells, but myogenin was negative. Whole exome sequencing demonstrated variants of unknown significance in multiple genes including PIK3R1 and NFIA . The morphologic and immunohistochemical profiles are consistent with a benign mesonephric neoplasm. This is the first report describing the immunohistochemical and whole exome sequencing results for a benign biphasic vaginal mesonephric neoplasm. To the best of our knowledge, benign mesonephric adenomyofibroma has not been previously reported in this anatomic location.

Prognostic value of isolated tumor cells in sentinel lymph nodes in low risk endometrial cancer: results from an international multi-institutional study.

OBJECTIVE: The prognostic significance of isolated tumor cells (≤0.2 mm) in sentinel lymph nodes (SLNs) of endometrial cancer patients is still unclear. Our aim was to assess the prognostic value of isolated tumor cells in patients with low risk endometrial cancer who underwent SLN biopsy and did not receive adjuvant therapy. Outcomes were compared with node negative patients. METHODS: Patients with SLNs-isolated tumor cells between 2013 and 2019 were identified from 15 centers worldwide, while SLN negative patients were identified from Mayo Clinic, Rochester, between 2013 and 2018. Only low risk patients (stage IA, endometrioid histology, grade 1 or 2) who did not receive any adjuvant therapy were included. Primary outcomes were recurrence free, non-vaginal recurrence free, and overall survival, evaluated with Kaplan-Meier methods. RESULTS: 494 patients (42 isolated tumor cells and 452 node negative) were included. There were 21 (4.3%) recurrences (5 SLNs-isolated tumor cells, 16 node negative); recurrence was vaginal in six patients (1 isolated tumor cells, 5 node negative), and non-vaginal in 15 (4 isolated tumor cells, 11 node negative). Median follow-up among those without recurrence was 2.3 years (interquartile range (IQR) 1.1-3.0) and 2.6 years (IQR 0.6-4.2) in the SLN-isolated tumor cell and node negative patients, respectively. The presence of SLNs-isolated tumor cells, lymphovascular space invasion, and International Federation of Obstetrics and Gynecology (FIGO) grade 2 were significant risk factors for recurrence on univariate analysis. SLN-isolated tumor cell patients had worse recurrence free survival (p<0.01) and non-vaginal recurrence free survival (p<0.01) compared with node negative patients. Similar results were observed in the subgroup of patients without lymphovascular space invasion (n=480). There was no difference in overall survival between the two cohorts in the full sample and the subset excluding patients with lymphovascular space invasion. CONCLUSIONS: Patients with SLNs-isolated tumor cells and low risk profile, without adjuvant therapy, had a significantly worse recurrence free survival compared with node negative patients with similar risk factors, after adjusting for grade and excluding patients with lymphovascular space invasion. However, the presence of SLNs-isolated tumor cells was not associated with worse overall survival.

Exact location of sensorimotor cortex injury after photochemical modulation; evidence of stroke based on stereological and morphometric studies in mice.

The integrity of the structural cerebral cortex is disrupted after stroke either at the macroscopic or microscopic levels. Therefore, many attempts have been gathered to circumvent stroke-associated problems in the brain tissue. The current study was aimed to design an animal model of photochemical stroke using rose bengal (RB) plus laser irradiation (L) after 10, 15, and 20 min (´) and evaluate its effect on the cerebral tissue using unbiased stereological quantitative methods and morphometric histological analysis. Photochemical stroke was induced by intraperitoneal injection of RB dye and further activation through the exposure of the right sensorimotor cortex with the green laser radiation (100 mW; 532 nm). Mice were randomly allocated into 4 groups (each in 15) as follows: control (10 µg/gbw RB), RB + 10'L, RB + 15'L, and RB + 20'L. Target irradiation site was adjusted to 2 mm lateral to the bregma. Vernier caliper morphometric evaluation, cresyl violet staining, and unbiased stereological assays including Cavalier's principle and point counting techniques were used to monitor the pathological changes and lesion volume on days 1, 3, and 7 after the ischemia induction. Our data showed that the mean diameter of the lesion site and lesion infarct volume in the group RB + 20'L) was significantly increased relative to the other groups (P < 0.05). Notably, the lesion volume and diameter in the group RB + 15'L was larger compared with the group RB + 10'L and control mice (P < 0.05). Data showed an increased acute inflammatory response such as hyperemia and edema 3 days after ischemic induction while the intensity of acute changes and lesion volume were reduced and replaced with necrotic and chronic pathological changes including astrogliosis on day 7. It is concluded that the laser irradiation of RB-injected mice at a distinct time period could induce the magnificent degenerative effects on the cerebral cortex which is similar to the stroke condition.

Evaluation of the Effect of Hyaluronic Acid-Based Biomaterial Enriched With Tenascin-C on the Behavior of the Neural Stem Cells.

One of the most important natural extracellular constituents is hyaluronic acid (HA) with the potential to develop a highly organized microenvironment. In the present study, we enriched HA hydrogel with tenascin-C (TN-C) and examined the viability and survival of mouse neural stem cells (NSCs) using different biological assays. Following NSCs isolation and expansion, their phenotype was identified using flow cytometry analysis. Cell survival was measured using MTT assay and DAPI staining after exposure to various concentrations of 50, 100, 200, and 400 nM TN-C. Using acridine orange/ethidium bromide staining, we measured the number of live and necrotic cells after exposure to the combination of HA and TN-C. MTT assay revealed the highest NSCs viability rate in the group exposed to 100 nM TN-C compared to other groups, and a combination of 1% HA + 100 nM TN-C increased the viability of NSCs compared to the HA group after 24 hours. Electron scanning microscopy revealed the higher attachment of these cells to the HA + 100 nM TN-C substrate relative to the HA substrate. Epifluorescence imaging and DAPI staining of loaded cells on HA + 100 nM TN-C substrate significantly increased the number of NSCs per field over 72 hours compared to the HA group (P < 0.05). Live and dead assay revealed that the number of live NSCs significantly increased in the HA + 100 TN-C group compared to HA and control groups. The enrichment of HA substrate with TN-C promoted viability and survival of NSCs and could be applied in neural tissue engineering approaches and regenerative medicine.

Human epidermal growth factor 2 (HER2) in early stage uterine serous carcinoma: A multi-institutional cohort study.

BACKGROUND: Human epidermal growth factor receptor 2 (HER2) has emerged as an important prognostic and therapeutic target in advanced stage and recurrent uterine serous carcinoma (USC). The significance of tumoral HER2 expression in early-stage disease has not been established. METHODS: This multi-center cohort study included women with stage I USC treated from 2000 to 2019. Demographic, treatment, recurrence, and survival data were collected. Immunohistochemistry (IHC) was performed for HER2 and scored 0-3+. Equivocal IHC results (2+) were further tested with fluorescence in-situ hybridization (FISH). HER2 positivity was defined as 3+ IHC or FISH positive. RESULTS: One hundred sixty-nine patients with stage I USC were tested for HER2; 26% were HER2-positive. There were no significant differences in age, race, stage, adjuvant therapy, or follow-up duration between the HER2-positive and negative cohorts. Presence of lymph-vascular space invasion was correlated with HER2-positive tumors (p = .003). After a median follow-up of 50 months, there were 43 (25.4%) recurrences. There were significantly more recurrences in the HER2-positive cohort (50.0% vs 16.8%, p < .001). HER2 positive tumors were associated with worse progression-free (PFS) and overall survival (OS) (p < .001 and p = .024). On multivariate analysis, HER2 positive tumors were associated with inferior PFS (aHR 3.50, 95%CI 1.84-6.67; p < .001) and OS (aHR 2.00, 95%CI 1.04-3.88; p = .039) compared to HER2-negative tumors. CONCLUSIONS: Given its significant association with worse recurrence and survival outcomes, HER2 positivity appears to be a prognostic biomarker in women with stage I uterine serous carcinoma. These data provide support for clinical trials with anti-HER2-directed therapy in early-stage disease.

Osteoconduction of Unrestricted Somatic Stem Cells on an Electrospun Polylactic-Co-Glycolic Acid Scaffold Coated with Nanohydroxyapatite.

The limitation of traditional bone grafts could be overcome by applying engineered bone constructs, which are mainly produced by seeding suitable stem cells on appropriate scaffolds. So far, bone marrow-derived stromal cells have been the most applied cells in bone tissue engineering, but current data show that unrestricted somatic stem cells (USSCs) from human cord blood might actually be a better stem cell source due to the accessibility and noninvasive procedure of collection. In this study, we cultured USSCs on a plasma-treated electrospun polylactic-co-glycolic acid (PLGA) scaffold coated with nanohydroxyapatite (nHA). Adhesion and proliferation of USSCs on PLGA/nHA were assessed by scanning electron microscopy and MTT assay. Osteogenic differentiation of USSCs into osteoblast lineage cells was evaluated via alkaline phosphatase (ALP) activity and real-time polymerase chain reaction. Our observation showed that USSCs attached and proliferated on PLGA/nHA. Osteogenic differentiation was confirmed by increased ALP activity and OSTEONECTIN expression in USSCs on PLGA/nHA after the 1st week of the osteogenic period. Therefore, using USSCs on electrospun PLGA/nHA is a promising approach in bone tissue engineering.

An unusual case of metastatic trophoblastic neoplasm presenting with diffuse cystic lung disease and pulmonary artery pseudoaneurysms in a teenager.

Diffuse cystic lung diseases (DCLDs) are a diverse group of lung disorders characterized by the presence of multiple air filled cysts within the lung tissue. These cysts are thin walled and surrounded by normal lung tissue. In adults, DCLD can be associated with various conditions such as lymphangioleiomyomatosis (LAM), Langerhans cell histiocytosis, cancers, and more. In children, DCLD is often linked to lung developmental abnormalities, with bronchopulmonary dysplasia being a common cause. Patients with pulmonary cysts are typically asymptomatic, but some may experience mild symptoms or pneumothorax. While DCLD in children is rarely due to malignancy, metastatic lung disease can be a cause. It is important for clinicians to be aware of the possibility of metastatic lung disease when encountering DCLD.

Uterine Leiomyosarcoma Associated With Perivascular Epithelioid Cell Tumor: A Phenomenon of Differentiation/Dedifferentiation and Evidence Suggesting Cell-of-Origin.

Perivascular epithelioid cell tumor (PEComa) is a mesenchymal tumor thought to originate from perivascular epithelioid cells (PECs). The normal counterpart to PEC, however, has not been identified in any human organ, and the debate as to whether PEComa is related to smooth muscle tumors has persisted for many years. The current series characterizes 4 cases of uterine leiomyosarcoma (LMS) coexisting with PEComas. All cases exhibited an abrupt transition from the LMS to PEComa components. The LMS component displayed typical spindled morphology and fascicular growth pattern and was diffusely positive for desmin and smooth muscle myosin heavy chain, completely negative for HMB-45 and Melan A, and either negative or had focal/weak expression of cathepsin K and GPNMB. In contrast, the PEComa tumor cells in case 1 contained glycogen or lipid-distended cytoplasm with a foamy appearance (low grade), and in cases 2, 3, and 4, they displayed a similar morphology characterized by epithelioid cells with eosinophilic and granular cytoplasm and high-grade nuclear atypia. Different from the LMS component, the epithelioid PEComa cells in all cases were focally positive for HMB-45, and diffusely immunoreactive for cathepsin K and GPNMB. Melan A was focally positive in cases 1 and 3. Loss of fumarate hydratase expression (case 1) and RB1 expression (cases 2, 3, 4) was identified in both LMS and PEComa components, indicating that they are clonally related. In addition, both components showed an identical TP53 p.R196* somatic mutation and complete loss of p53 and ATRX expression in case 2 and complete loss of p53 expression in case 3. We hypothesize that LMSs containing smooth muscle progenitor cells may give rise to divergent, lineage-specific PEComatous lesions through differentiation or dedifferentiation. While we do not dispute the recognition of PEComas as a distinct entity, we advocate the hypothesis that modified smooth muscle cells represent the origin of a subset of PEComas, and our case series provides evidence to suggest this theory.

Ovarian non-gestational placental site trophoblastic tumor with lung metastasis: further evidence for a distinct category of trophoblastic neoplasm.

We previously described a series of cases which characterize a distinct group of primary ovarian placental site trophoblastic tumor (PSTT) and epithelioid trophoblastic tumor (ETT) as a non-gestational set consistent with germ cell type/origin. Here we report a new case of ovarian non-gestational PSTT. The patient was a 13 year-old young female admitted for a spontaneous pneumothorax of the left lung. The pathology of lung wedge excision specimen demonstrated metastatic PSTT and ovarian biopsy showed atypical intermediate trophoblastic proliferation which was found to be PSTT in the subsequent salpingo-oophorectomy specimen. In the ovary, the tumor was composed of singly dispersed or small clusters of predominantly mononuclear cells and rare multinucleated cells extensively infiltrating the ovarian parenchyma, tubal mucosa, and paraovarian/paratubal soft tissue. A minor component of mature cystic teratoma (less than 5% of total tumor volume) was present. Immunohistochemically, the neoplastic cells of main tumor were diffusely immunoreactive for hPL, Gata3 and AE1/AE3, and had only rare hCG-positive or p63-positive cells. The morphology and immunohistochemical results support a PSTT. Molecular genotyping revealed an identical genotype pattern between the normal lung tissue and the metastatic PSTT, indicating its non-gestational nature of germ cell type/origin. This case represents the first case of such tumor with distant (lung) metastasis. This case also provides further evidence to support our recommendation that primary ovarian non-gestational intermediate trophoblastic tumors of germ cell type/origin, including PSTT and ETT, should be formally recognized in classification systems.

High-Hole-Mobility Fiber Organic Electrochemical Transistors for Next-Generation Adaptive Neuromorphic Bio-Hybrid Technologies.

The latest developments in fiber design and materials science are paving the way for fibers to evolve from parts in passive components to functional parts in active fabrics. Designing conformable, organic electrochemical transistor (OECT) structures using poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) fibers has excellent potential for low-cost wearable bioelectronics, bio-hybrid devices, and adaptive neuromorphic technologies. However, to achieve high-performance, stable devices from PEDOT:PSS fibers, approaches are required to form electrodes on fibers with small diameters and poor wettability, that leads to irregular coatings. Additionally, PEDOT:PSS-fiber fabrication needs to move away from small batch processing to roll-to-roll or continuous processing. Here, it is shown that synergistic effects from a superior electrode/organic interface, and exceptional fiber alignment from continuous processing, enable PEDOT:PSS fiber-OECTs with stable contacts, high µC* product (1570.5 F cm-1 V-1 s-1 ), and high hole mobility over 45 cm2 V-1 s-1 . Fiber-electrochemical neuromorphic organic devices (fiber-ENODes) are developed to demonstrate that the high mobility fibers are promising building blocks for future bio-hybrid technologies. The fiber-ENODes demonstrate synaptic weight update in response to dopamine, as well as a form factor closely matching the neuronal axon terminal.

The Effect of Organic Semiconductor Electron Affinity on Preventing Parasitic Oxidation Reactions Limiting Performance of n-Type Organic Electrochemical Transistors.

A key challenge in the development of organic mixed ionic-electronic conducting materials (OMIEC) for high performance electrochemical transistors is their stable performance in ambient. When operating in aqueous electrolyte, potential reactions of the electrochemically injected electrons with air and water could hinder their persistence, leading to a reduction in charge transport. Here, the impact of deepening the LUMO energy level of a series of electron-transporting semiconducting polymers is evaluated, and subsequently rendering the most common oxidation processes of electron polarons thermodynamically unfavorable, on organic electrochemical transistors (OECTs) performance. Employing time resolved spectroelectrochemistry with three analogous polymers having varying electron affinities (EA), it is found that an EA below the thermodynamic threshold for oxidation of its electron polarons by oxygen significantly improves electron transport and lifetime in air. A polymer with a sufficiently large EA and subsequent thermodynamically unfavorable oxidation of electron polarons is reported, which is used as the semiconducting layer in an OECT, in its neutral and N-DMBI doped form, resulting in an excellent and air-stable OECT performance. These results show a general design methodology to avoid detrimental parasitic reactions under ambient conditions, and the benefits that arise in electrical performance.