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1.
JAMA Netw Open ; 7(7): e2421717, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-39042410

RESUMEN

Importance: Understanding gender differences in electronic health record (EHR) use among surgeons is crucial for addressing potential disparities in workload, compensation, and physician well-being. Objective: To investigate gender differences in EHR usage patterns. Design, Setting, and Participants: This cross-sectional study examined data from an EHR system (Epic Signal) at a single academic hospital from January to December 2022. Participants included 224 attending surgeons with patient encounters in the outpatient setting. Statistical analysis was performed from May 2023 to April 2024. Exposures: Surgeon's gender. Main Outcomes and Measures: The primary outcome variables were progress note length, documentation length, time spent in medical records, and time spent documenting patient encounters. Continuous variables were summarized with median and IQR and assessed via the Kruskal-Wallis test. Categorical variables were summarized using proportion and frequency and compared using the χ2 test. Multivariate linear regression was used with primary EHR usage variables as dependent variables and surgeon characteristics as independent variables. Results: This study included 222 529 patient encounters by 224 attending surgeons, of whom 68 (30%) were female and 156 (70%) were male. The median (IQR) time in practice was 14.0 (7.8-24.3) years. Male surgeons had more median (IQR) appointments per month (78.3 [39.2-130.6] vs 57.8 [25.7-89.8]; P = .005) and completed more medical records per month compared with female surgeons (43.0 [21.8-103.9] vs 29.1 [15.9-48.1]; P = .006). While there was no difference in median (IQR) time spent in the EHR system per month (664.1 [301.0-1299.1] vs 635.0 [315.6-1192.0] minutes; P = .89), female surgeons spent more time logged into the system both outside of 7am to 7pm (36.4 [7.8-67.6] vs 14.1 [5.4-52.2] min/mo; P = .05) and outside of scheduled clinic hours (134.8 [58.9-310.1] vs 105.2 [40.8-214.3] min/mo; P = .05). Female surgeons spent more median (IQR) time per note (4.8 [2.6-7.1] vs 2.5 [0.9-4.2] minutes; P < .001) compared with male surgeons. Male surgeons had a higher number of median (IQR) days logged in per month (17.7 [13.8-21.3] vs 15.7 [10.7-19.7] days; P = .03). Female surgeons wrote longer median (IQR) inpatient progress notes (6025.1 [3692.1-7786.7] vs 4307.7 [2808.9-5868.4] characters/note; P = .001) and had increased outpatient document length (6321.1 [4079.9-7825.0] vs 4445.3 [2934.7-6176.7] characters/note; P < .001). Additionally, female surgeons wrote a higher fraction of the notes manually (17% vs 12%; P = .006). After using multivariable linear regression models, male gender was associated with reduced character length for both documentations (regression coefficient, -1106.9 [95% CI, -1981.5 to -232.3]; P = .01) and progress notes (regression coefficient, -1119.0 [95% CI, -1974.1 to -263.9]; P = .01). Male gender was positively associated with total hospital medical records completed (regression coefficient, 47.3 [95% CI, 28.3-66.3]; P < .001). There was no difference associated with gender for time spent in each note, time spent outside of 7 am to 7 pm, or time spent outside scheduled clinic hours. Conclusions and Relevance: This cross-sectional study of EHR data found that female surgeons spent more time documenting patient encounters, wrote longer notes, and spent more time in the EHR system compared with male surgeons. These findings have important implications for understanding the differential burdens faced by female surgeons, including potential contributions to burnout and payment disparities.


Asunto(s)
Registros Electrónicos de Salud , Cirujanos , Humanos , Masculino , Femenino , Registros Electrónicos de Salud/estadística & datos numéricos , Estudios Transversales , Cirujanos/estadística & datos numéricos , Factores Sexuales , Persona de Mediana Edad , Adulto , Carga de Trabajo/estadística & datos numéricos
2.
World Neurosurg X ; 23: 100382, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38756754

RESUMEN

Background: Studies report patient race, income, and education influence spinal fusion outcomes; fewer studies, however, examine the influence of provider factors such as exposure to diversity or cultural sensitivity. Objective: To examine how providers' experience with diverse patient populations affects spinal fusion outcomes. Methods: Retrospective review of 39,680 patients undergoing lumbar and cervical fusions, 2003-2021, in Clinformatics® Data Mart national database. We used the provider patient racial diversity index (pRDI)-a published metric of physician exposure to diverse patients-to divide patients into groups based their provider's category (I, II, III) where patients treated by category III providers had surgeons with the most diverse patient populations. Multivariate regression models on propensity score-matched cohorts examined the association between patient SES and provider category on post-operative outcomes. Results: Black patients had decreased discharge home (OR 0.67; 95% CI 0.54-0.83) compared to white patients. Patients treated by category III providers had increased length of stay (Coeff. 0.62; 95% CI 0.43-0.81), charge (Coeff. 36800; 95% CI 29,200-44,400), and decreased discharge home (OR 0.90; 95% CI 0.83-0.97) compared to patients treated by category I providers. Asian patients treated by category II providers had decreased readmission (OR 0.38; 95% CI 0.14-0.96), and Black patients treated by category III providers had increased discharge home (OR 1.41; 95% CI 1.1-1.9) compared to those treated by category I providers. Conclusion: While our study found two specific instances of improved spine surgery outcomes for minority patients treated by providers serving diverse patient populations, we present mixed findings overall. This study serves as the foundation for future research to better understand how provider pRDI affects outcomes in patients undergoing lumbar and cervical spine surgery.

3.
N Am Spine Soc J ; 18: 100321, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38741936

RESUMEN

Background: The COVID-19 pandemic disrupted healthcare access and utilization throughout the US, with variable impact on patients of different socioeconomic status (SES) and race. We characterize pre-pandemic and pandemic demographic and SES trends of lumbar fusion patients in the US. Methods: Adults undergoing first-time lumbar fusion 1/1/2004-3/31/2021 were assessed in Clinformatics® Data Mart for patient age, geographical location, gender, race, education level, net worth, and Charlson Comorbidity Index (CCI). Multivariable regression models were used to evaluate the significance of trends over time, with a focus on pandemic trends 2020-2021 versus previous trends 2004-2019. Results: The total 217,204 patients underwent lumbar fusions, 1/1/2004-3/31/2021. The numbers and per capita rates of lumbar fusions increased 2004-2019 and decreased in 2020 (first year of COVID-19 pandemic), with large variation in geographic distribution. There was overall a significant decrease in proportion of White patients undergoing lumbar fusion over time (OR=0.997, p<.001), though they were more likely to undergo surgery during the pandemic (OR=1.016, p<.001). From 2004-2021, patients were more likely to be educated beyond high school. Additionally, patients in the highest (>$500k) and lowest (<$25k) net worth categories had significantly more fusions over time (p<.001). During the pandemic (2020-2021), patients in higher net worth groups were more likely to undergo lumbar fusions ($150k-249k & $250k-499k: p<.001) whereas patients in the lowest net worth group had decreased rate of surgeries (p<.001). Lastly, patients' CCI increased significantly from 2004 to 2021 (coefficient=0.124, p<.001), and this trend held true during the pandemic (coefficient=0.179, p<.001). Conclusions: To the best of our knowledge, our work represents the most comprehensive and recent characterization of SES variables in lumbar fusion rates. Unsurprisingly, lumbar fusions decreased overall with the onset of the COVID-19 pandemic. Importantly, disparities in fusion patients across patient race and wealth widened during the pandemic, reversing years of progress, a lesson we can learn for future public health emergencies.

4.
World Neurosurg ; 182: e107-e125, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38000672

RESUMEN

BACKGROUND: Cervical fusion rates increased in the U.S. exponentially 1990-2014, but trends leading up to/during the COVID-19 pandemic have not been fully evaluated by patient socioeconomic status (SES). Here, we provide the most recent, comprehensive characterization of demographic and SES trends in cervical fusions, including during the pandemic. METHODS: We collected the following variables on adults undergoing cervical fusions, 1/1/2004-3/31/2021, in Optum's Clinformatics Data Mart: age, Charlson Comorbidity Index, provider's practicing state, gender, race, education, and net worth. We performed multivariate linear and logistic regression to evaluate associations of cervical fusion rates with SES variables. RESULTS: Cervical fusion rates increased 2004-2016, then decreased 2016-2020. Proportions of Asian, Black, and Hispanic patients undergoing cervical fusions increased (OR = 1.001,1.001,1.004, P < 0.01), with a corresponding decrease in White patients (OR = 0.996, P < 0.001) over time. There were increases in cervical fusions in higher education groups (OR = 1.006, 1.002, P < 0.001) and lowest net worth group (OR = 1.012, P < 0.001). During the pandemic, proportions of White (OR = 1.015, P < 0.01) and wealthier patients (OR ≥ 1.015, P < 0.01) undergoing cervical fusions increased. CONCLUSIONS: We present the first documented decrease in annual cervical surgery rates in the U.S. Our data reveal a bimodal distribution for cervical fusion patients, with racial-minority, lower-net-worth, and highly-educated patients receiving increasing proportions of surgical interventions. White and wealthier patients were more likely to undergo cervical fusions during the COVID-19 pandemic, which has been reported in other areas of medicine but not yet in spine surgery. There is still considerable work needed to improve equitable access to spine care for the entire U.S.


Asunto(s)
COVID-19 , Enfermedades de la Columna Vertebral , Fusión Vertebral , Adulto , Humanos , Pandemias , COVID-19/epidemiología , Enfermedades de la Columna Vertebral/cirugía , Factores Socioeconómicos , Demografía , Estudios Retrospectivos
5.
Neuron ; 112(3): 500-514.e5, 2024 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-38016471

RESUMEN

Striatal dopamine (DA) release has long been linked to reward processing, but it remains controversial whether DA release reflects costs or benefits and how these signals vary with motivation. Here, we measure DA release in the nucleus accumbens (NAc) and dorsolateral striatum (DLS) while independently varying costs and benefits and apply behavioral economic principles to determine a mouse's level of motivation. We reveal that DA release in both structures incorporates both reward magnitude and sunk cost. Surprisingly, motivation was inversely correlated with reward-evoked DA release. Furthermore, optogenetically evoked DA release was also heavily dependent on sunk cost. Our results reconcile previous disparate findings by demonstrating that striatal DA release simultaneously encodes cost, benefit, and motivation but in distinct manners over different timescales. Future work will be necessary to determine whether the reduction in phasic DA release in highly motivated animals is due to changes in tonic DA levels.


Asunto(s)
Dopamina , Motivación , Ratones , Animales , Dopamina/fisiología , Cuerpo Estriado/fisiología , Neostriado , Núcleo Accumbens/fisiología , Recompensa
6.
Clin Spine Surg ; 37(2): E65-E72, 2024 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-37691156

RESUMEN

STUDY DESIGN: A retrospective observational study. OBJECTIVE: The aim of this study was to compare postoperative outcomes following cervical fusion based on socioeconomic status (SES) variables including race, education, net worth, and homeownership status. SUMMARY OF BACKGROUND DATA: Previous studies have demonstrated the effects of patient race and income on outcomes following cervical fusion procedures. However, no study to date has comprehensively examined the impact of multiple SES variables. We hypothesized that race, education, net worth, and homeownership influence important outcomes following cervical fusion. MATERIALS AND METHODS: Optum's de-identified Clinformatics Data Mart (CDM) database was queried for patients undergoing first-time inpatient cervical fusion from 2003 to 2021. Patient demographics, SES variables, and the Charlson comorbidity index were obtained. Primary outcomes were hospital length of stay and 30-day rates of reoperation, readmission, and postoperative complications. Secondary outcomes included postoperative emergency room visits, discharge status, and total hospital charges. RESULTS: A total of 111,914 patients underwent cervical spinal fusion from 2003 to 2021. Multivariate analysis revealed that after controlling for age, sex, and Charlson comorbidity index, Black race was associated with a higher rate of 30-day readmissions [odds ratio (OR): 1.11, 95% CI: 1.03-1.20]. Lower net worth (vs. >$500K) and renting (vs. owning a home) were significantly associated with both higher rates of 30-day readmissions (OR: 1.29, 95% CI: 1.17-1.41; OR: 1.34, 95% CI: 1.22-1.49), and emergency room visits (OR: 1.29, 95% CI: 1.18-1.42; OR: 1.11, 95% CI: 1.00-1.23). Lower net worth (vs. >$500K) was also associated with increased complications (OR: 1.22, 95% CI: 1.14-1.31). CONCLUSION: Socioeconomic variables, including patient race, education, and net worth, influence postoperative metrics in cervical spinal fusion surgery. Future studies should focus on developing and implementing targeted interventions based on patient SES to reduce disparity.


Asunto(s)
Enfermedades de la Columna Vertebral , Fusión Vertebral , Humanos , Fusión Vertebral/métodos , Complicaciones Posoperatorias/etiología , Enfermedades de la Columna Vertebral/complicaciones , Estudios Retrospectivos , Factores Socioeconómicos , Vértebras Cervicales/cirugía
7.
J Endocr Soc ; 7(7): bvad085, 2023 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-37388575

RESUMEN

Purpose: Osteoporosis affects more than 200 million individuals worldwide and predisposes to vertebral compression fractures (VCFs). Given undertreatment of fragility fractures, including VCFs, we investigate current anti-osteoporotic medication prescribing trends. Methods: Patients 50 and older with a diagnosis of primary closed thoracolumbar VCF between 2004 and 2019 were identified from the Clinformatics® Data Mart database. Multivariate analysis was performed for demographic and clinical treatment and outcome variables. Results: Of 143 081 patients with primary VCFs, 16 780 (11.7%) were started on anti-osteoporotic medication within a year; 126 301 (88.3%) patients were not started on medication. The medication cohort was older (75.4 ± 9.3 vs 74.0 ± 12.3 years, P < .001), had higher Elixhauser Comorbidity Index scores (4.7 ± 6.2 vs 4.3 ± 6.7, P < .001), was more likely to be female (81.1% vs 64.4%, P < .001), and was more likely to have a formal osteoporosis diagnosis (47.8% vs 32.9%) than the group that did not receive medication. Alendronate (63.4%) and calcitonin (27.8%) were the most commonly initiated medications. The proportion of individuals receiving anti-osteoporotic medication within the year following VCF peaked in 2008 (15.2%), then declined until 2012 with a modest increase afterward. Conclusions: Osteoporosis remains undertreated after low-energy VCFs. New anti-osteoporotic medication classes have been approved in recent years. Bisphosphonates remain the most prescribed class. Increasing recognition and treatment of osteoporosis is paramount to decreasing the risk of subsequent fractures.

8.
Neurosurgery ; 92(5): 905-914, 2023 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-36606803

RESUMEN

BACKGROUND: Recent studies suggest that socioeconomic status (SES) influences outcomes after spinal fusion. The influence of SES on postoperative outcomes is increasingly relevant as rates of lumbar fusion rise. OBJECTIVE: To determine the influence of SES variables including race, education, net worth, and homeownership on postoperative outcomes. METHODS: Optum's deidentified Clinformatics Data Mart Database was used to conduct a retrospective review of SES variables for patients undergoing first-time, inpatient lumbar fusion from 2003 to 2021. Primary outcomes included hospital length of stay (LOS) and 30-day reoperation, readmission, and postoperative complication rates. Secondary outcomes included postoperative emergency room visits, discharge status, and total hospital charges. RESULTS: In total, 217 204 patients were identified. On multivariate analysis, Asian, Black, and Hispanic races were associated with increased LOS (Coeff. [coefficient] 0.92, 95% CI 0.68-1.15; Coeff. 0.61, 95% CI 0.51-0.71; Coeff. 0.43, 95% CI 0.32-0.55). Less than 12th grade education (vs greater than a bachelor's degree) was associated with increased odds of reoperation (OR [odds ratio] 1.88, 95% CI 1.03-3.42). Decreased net worth was associated with increased odds of readmission (OR 1.32, 95% CI 1.25-1.40) and complication (OR 1.14, 95% CI 1.10-1.20). Renting a home (vs homeownership) was associated with increased LOS, readmissions, and total charges (Coeff. 0.30, 95% CI 0.17-0.43; OR 1.19, 95% CI 1.11-1.30; Coeff. 13 200, 95% CI 9000-17 000). CONCLUSION: Black race, less than 12th grade education, <$25K net worth, and lack of homeownership were associated with poorer postoperative outcomes and increased costs. Increasing perioperative support for patients with these sociodemographic risk factors may improve postoperative outcomes.


Asunto(s)
Vértebras Lumbares , Fusión Vertebral , Humanos , Vértebras Lumbares/cirugía , Tiempo de Internación , Reoperación , Complicaciones Posoperatorias/etiología , Fusión Vertebral/efectos adversos , Estudios Retrospectivos , Factores Socioeconómicos , Readmisión del Paciente
9.
Surg Open Sci ; 10: 116-134, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36132940

RESUMEN

Background: Laparoscopic cholecystectomy is frequently performed for acute cholecystitis and symptomatic cholelithiasis. Considerable variation in the execution of key steps of the operation remains. We conducted a systematic review of evidence regarding best practices for critical intraoperative steps for laparoscopic cholecystectomy. Methods: We identified 5 main intraoperative decision points in laparoscopic cholecystectomy: (1) number and position of laparoscopic ports; (2) identification of cystic artery and duct; (3) division of cystic artery and duct; (4) indications for subtotal cholecystectomy; and (5) retrieval of the gallbladder. PubMed, EMBASE, and Web of Science were queried for relevant studies. Randomized controlled trials and systematic reviews were included for analysis, and evidence quality was assessed using the Grading of Recommendations, Assessment, Development, and Evaluation framework. Results: Fifty-two articles were included. Although all port configurations were comparable from a safety standpoint, fewer ports sometimes resulted in improved cosmesis or decreased pain but longer operative times. The critical view of safety should be obtained for identification of the cystic duct and artery but may be obtained through fundus-first dissection and augmented with cholangiography or ultrasound. Insufficient evidence exists to compare harmonic-shear, clipless ligation against clip ligation of the cystic duct and artery. Stump closure during subtotal cholecystectomy may reduce rates of bile leak and reoperation. Use of retrieval bag for gallbladder extraction results in minimal benefit. Most studies were underpowered to detect differences in incidence of rare complications. Conclusion: Key operative steps of laparoscopic cholecystectomy should be informed by both compiled data and surgeon preference/patient considerations.

10.
JAMA Surg ; 157(2): 129-135, 2022 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-34817552

RESUMEN

Importance: Critical burn management decisions rely on accurate percent total body surface area (%TBSA) burn estimation. Existing %TBSA burn estimation models (eg, Lund-Browder chart and rule of nines) were derived from a linear formula and a limited number of individuals a century ago and do not reflect the range of body habitus of the modern population. Objective: To develop a practical %TBSA burn estimation tool that accounts for exact burn injury pattern, sex, and body habitus. Design, Setting, and Participants: This population-based cohort study evaluated the efficacy of a computer vision algorithm application in processing an adult laser body scan data set. High-resolution surface anthropometry laser body scans of 3047 North American and European adults aged 18 to 65 years from the Civilian American and European Surface Anthropometry Resource data set (1998-2001) were included. Of these, 1517 participants (49.8%) were male. Race and ethnicity data were not available for analysis. Analyses were conducted in 2020. Main Outcomes and Measures: The contributory %TBSA for 18 body regions in each individual. Mobile application for real-time %TBSA burn computation based on sex, habitus, and exact burn injury pattern. Results: Of the 3047 individuals aged 18 to 65 years for whom body scans were available, 1517 (49.8%) were male. Wide individual variability was found in the extent to which major body regions contributed to %TBSA, especially in the torso and legs. Anterior torso %TBSA increased with increasing body habitus (mean [SD], 15.1 [0.9] to 19.1 [2.0] for male individuals; 15.1 [0.8] to 18.0 [1.7] for female individuals). This increase was attributable to increase in abdomen %TBSA (mean [SD], 5.3 [0.7] to 8.7 [1.8]) among male individuals and increase in abdomen (mean [SD], 4.6 [0.6] to 6.8 [1.7]) and pelvis (mean [SD], 1.5 [0.2] to 2.9 [0.9]) %TBSAs among female individuals. For most body regions, Lund-Browder chart and rule of nines estimates fell outside the population's measured interquartile ranges. The mobile application tested in this study, Burn Area, facilitated accurate %TBSA burn computation based on exact burn injury pattern for 10 sex and body habitus-specific models. Conclusions and Relevance: Computer vision algorithm application to a large laser body scan data set may provide a practical tool that facilitates accurate %TBSA burn computation in the modern era.


Asunto(s)
Superficie Corporal , Quemaduras/patología , Imagenología Tridimensional/métodos , Rayos Láser , Aplicaciones Móviles , Adolescente , Adulto , Anciano , Algoritmos , Femenino , Humanos , Masculino , Persona de Mediana Edad
11.
Surgery ; 170(4): 1260-1267, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-33888318

RESUMEN

BACKGROUND: Traumatic hemothorax is a common injury that invites diagnostic and management strategy debates. Evidence-based management has been associated with improved care efficiency. However, the literature abounds with long-debated, re-emerging, and new questions. We aimed to consolidate up-to-date evidence on traumatic hemothoraces, focusing on clinical conundra debated in literature. METHODS: We conducted a scoping review of 21 clinical conundra in traumatic hemothorax diagnosis and management according to PRISMA-ScR guidelines. Experimental and observational studies evaluating patients (aged ≥18 years) with traumatic hemothoraces were identified through database searches (PubMed, EMBASE, Web of Science, Cochrane Library; database inception to Sep, 26 2020) and bibliography reviews of selected articles. Three reviewers screened and selected articles using standardized forms. RESULTS: We screened 1,440 articles for eligibility, of which 71 met criteria for synthesis. The review comprises 6 sections: (1) Presumptive antibiotics before tube thoracostomy; (2) Initial diagnostic and intervention decisions; (3) Chest tubes; (4) Retained hemothoraces; (5) Delayed hemothoraces; and (6) Chest tube removal). The 21 conundra across these sections follow the format of a question, our recommendation based on interpretation of available evidence, and succinct rationale. Rationale sections detail knowledge gaps and opportunities for future research. CONCLUSION: Even practices engrained into surgical dogma, such as obtaining chest x-rays after inserting or removing chest tubes and mandating operation for patients who develop chest tube output above a certain threshold, deserve re-evaluation. Some knowledge gaps require rigorous future investigation; sound clinical judgment can likely supplement others.


Asunto(s)
Tubos Torácicos , Remoción de Dispositivos/métodos , Drenaje/instrumentación , Hemotórax/cirugía , Traumatismos Torácicos/complicaciones , Toracostomía/métodos , Hemotórax/diagnóstico , Hemotórax/etiología , Humanos , Puntaje de Gravedad del Traumatismo , Traumatismos Torácicos/diagnóstico , Traumatismos Torácicos/cirugía , Tomografía Computarizada por Rayos X
12.
J Am Chem Soc ; 142(47): 19956-19968, 2020 11 25.
Artículo en Inglés | MEDLINE | ID: mdl-33170675

RESUMEN

The fabrication of dynamic, transformable biomaterials that respond to environmental cues represents a significant step forward in the development of synthetic materials that rival their highly functional, natural counterparts. Here, we describe the design and synthesis of crystalline supramolecular architectures from charge-complementary heteromeric pairs of collagen-mimetic peptides (CMPs). Under appropriate conditions, CMP pairs spontaneously assemble into either 1D ultraporous (pore diameter >100 nm) tubes or 2D bilayer nanosheets due to the structural asymmetry that arises from heteromeric self-association. Crystalline collagen tubes represent a heretofore unobserved morphology of this common biomaterial. In-depth structural characterization from a suite of biophysical methods, including TEM, AFM, high-resolution cryo-EM, and SAXS/WAXS measurements, reveals that the sheet and tube assemblies possess a similar underlying lattice structure. The experimental evidence suggests that the tubular structures are a consequence of the self-scrolling of incipient 2D layers of collagen triple helices and that the scrolling direction determines the formation of two distinct structural isoforms. Furthermore, we show that nanosheets and tubes can spontaneously interconvert through manipulation of the assembly pH and systematic adjustment of the CMP sequence. Altogether, we establish initial guidelines for the construction of dynamically responsive 1D and 2D assemblies that undergo a structurally programmed morphological transition.


Asunto(s)
Colágeno/química , Nanoestructuras/química , Péptidos/química , Secuencia de Aminoácidos , Microscopía por Crioelectrón , Concentración de Iones de Hidrógeno , Microscopía de Fuerza Atómica , Nanotubos/química , Porosidad
13.
J Am Chem Soc ; 141(51): 20107-20117, 2019 12 26.
Artículo en Inglés | MEDLINE | ID: mdl-31800228

RESUMEN

Engineering free-standing 2D nanomaterials with compositional, spatial, and functional control across size regimes from the nano- to mesoscale represents a significant challenge. Herein, we demonstrate a straightforward strategy for the thermodynamically controlled fabrication of multicomponent sectored nanosheets in which each sector can be chemically and spatially addressed independently and orthogonally. Collagen triple helices, comprising collagen-mimetic peptides (CMPs), are employed as molecularly programmable crystallizable units. Modulating their thermodynamic stability affords the controlled synthesis of 2D core-shell nanostructures via thermally driven heteroepitaxial growth. Structural information, gathered from SAXS and cryo-TEM, reveals that the distinct peptide domains maintain their intrinsic lattice structure and illuminates various mechanisms employed by CMP triple helices to alleviate the elastic strain associated with the interfacial lattice mismatch. Finally, we demonstrate that different sectors of the sheet surface can be selectively functionalized using bioorthogonal conjugation chemistry. Altogether, we establish a robust platform for constructing multifunctional 2D nanoarchitectures in which one can systematically program their compositional, spatial, and functional properties, which is a significant step toward their deployment into functional nanoscale devices.

14.
Angew Chem Int Ed Engl ; 58(38): 13507-13512, 2019 09 16.
Artículo en Inglés | MEDLINE | ID: mdl-31291499

RESUMEN

The successful integration of 2D nanomaterials into functional devices hinges on developing fabrication methods that afford hierarchical control across length scales of the entire assembly. We demonstrate structural control over a class of crystalline 2D nanosheets assembled from collagen triple helices. By lengthening the triple helix unit through sequential additions of Pro-Hyp-Gly triads, we achieved sub-angstrom tuning over the 2D lattice. These subtle changes influence the overall nanosheet size, which can be adjusted across the mesoscale size regime. The internal structure was observed by cryo-TEM with direct electron detection, which provides real-space high-resolution images, in which individual triple helices comprising the lattice can be clearly discerned. These results establish a general strategy for tuning the structural hierarchy of 2D nanomaterials that employ rigid, cylindrical structural units.

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