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1.
bioRxiv ; 2024 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-39314323

RESUMEN

Cancers coopt stress-response pathways to drive oncogenesis, dodge immune surveillance, and resist cytotoxic therapies. Several of these provide protection from ferroptosis, iron-mediated oxidative cell death. Here, we found dramatic sensitization to ferroptosis upon disruption of cap-dependent translation in diffuse large B-cell lymphoma (DLBCL). Specifically, rocaglate inhibitors of the eIF4A1 RNA helicase synergized with pharmacologic ferroptosis inducers, driven by a collapse of glutathione production that protects polyunsaturated fatty acids from ferroptotic oxidation. These effects occur despite initial up-regulation of specific protective factors. We find lost translation of NRF2, oncogenic master regulator of antioxidant gene-expression, is a key consequence of eIF4A1 inhibition. In vivo, combination of the clinical rocaglate zotatifin with a pharmacologically optimized ferroptosis inducer eradicated DLBCL patient derived xenografts. Moreover, we found zotatifin pre-exposure sensitized DLBCL to CD19-directed chimeric antigen receptor (CAR-19) T cells. Translational disruption therefore provides new opportunities to leverage therapeutic impacts of ferroptosis inducers including cytotoxic immunotherapies.

2.
J Am Chem Soc ; 146(39): 27173-27178, 2024 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-39287969

RESUMEN

Despite their potential relevance as molecular models for industrial and biological catalysis, well-defined mononuclear iron carbide complexes are unknown, in part due to the limited number of appropriate C1 synthons. Here, we show the ability of the cyaphide anion (C≡P-) to serve as a C1 source. The high spin (S = 2) cyaphide complex PhB(tBuIm)3Fe-C≡P (PhB(tBuIm)3- = phenyl(tris(3-tert-butylimidazol-2-ylidene)borate) is readily accessed using the new cyaphide transfer reagent [Mg(DippNacNac)(CP)]2 (DippNacNac = CH{C(CH3)N(Dipp)}2 and Dipp = 2,6-di(iso-propyl)phenyl). Phosphorus atom abstraction is effected by the three-coordinate Mo(III) complex Mo(NtBuAr)3 (Ar = 3,5-Me2C6H3), which produces the known phosphide (tBuArN)3Mo≡P along with a transient iron carbide complex PhB(tBuIm)3Fe≡C. Electronic structure calculations reveal that PhB(tBuIm)3Fe≡C adopts a doublet ground state with nonzero spin density on the carbide ligand. While isolation of this complex is thwarted by rapid dimerization to afford the corresponding diiron ethynediyl complex, the carbide can be intercepted by styrene to provide an iron alkylidene.

3.
J Biol Chem ; 300(10): 107752, 2024 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-39260693

RESUMEN

The ST6GAL1 sialyltransferase is overexpressed in multiple cancers, including pancreatic ductal adenocarcinoma (PDAC). ST6GAL1 adds an α2-6-linked sialic acid to N-glycosylated membrane receptors, which consequently modulates receptor structure and function. While many studies have investigated the effects of ST6GAL1 on cell phenotype, there is a dearth of knowledge regarding mechanisms that regulate ST6GAL1 expression. In the current study, we evaluated the regulation of ST6GAL1 by two pro-inflammatory cytokines, IL-1ß and IL-6, which are abundant within the PDAC tumor microenvironment. Cytokine activity was monitored using the Suit-2 PDAC cell line and two Suit-2-derived metastatic subclones, S2-013 and S2-LM7AA. For all three cell models, treatment with IL-1ß or IL-6 increased the expression of ST6GAL1 protein and mRNA. Specifically, IL-1ß and IL-6 induced expression of the ST6GAL1 YZ mRNA isoform, which is driven by the P3 promoter. The ST6GAL1 H and X isoforms were not detected. Promoter reporter assays confirmed that IL-1ß and IL-6 activated transcription from the P3 promoter. We then examined downstream signaling mechanisms. IL-1ß is known to signal through the NFκB transcription factor, whereas IL-6 signals through the STAT3 transcription factor. CUT&RUN experiments revealed that IL-1ß promoted the binding of NFκB to the ST6GAL1 P3 promoter, and IL-6 induced the binding of STAT3 to the P3 promoter. Finally, we determined that inhibitors of NFκB and STAT3 blocked the upregulation of ST6GAL1 stimulated by IL-1ß and IL-6, respectively. Together, these results highlight a novel molecular pathway by which cytokines within the tumor microenvironment stimulate the upregulation of ST6GAL1 in PDAC cells.

6.
J Surg Res ; 302: 200-207, 2024 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-39098118

RESUMEN

INTRODUCTION: Presenting health information at a sixth-grade reading level is advised to accommodate the general public's abilities. Breast cancer (BC) is the second-most common malignancy in women, but the readability of online BC information in English and Spanish, the two most commonly spoken languages in the United States, is uncertain. METHODS: Three search engines were queried using: "how to do a breast examination," "when do I need a mammogram," and "what are the treatment options for breast cancer" in English and Spanish. Sixty websites in each language were studied and classified by source type and origin. Three readability frameworks in each language were applied: Flesch Kincaid Reading Ease, Flesch Kincaid Grade Level, and Simple Measure of Gobbledygook (SMOG) for English, and Fernández-Huerta, Spaulding, and Spanish adaptation of SMOG for Spanish. Median readability scores were calculated, and corresponding grade level determined. The percentage of websites requiring reading abilities >sixth grade level was calculated. RESULTS: English-language websites were predominantly hospital-affiliated (43.3%), while Spanish websites predominantly originated from foundation/advocacy sources (43.3%). Reading difficulty varied across languages: English websites ranged from 5th-12th grade (Flesch Kincaid Grade Level/Flesch Kincaid Reading Ease: 78.3%/98.3% above sixth grade), while Spanish websites spanned 4th-10th grade (Spaulding/Fernández-Huerta: 95%/100% above sixth grade). SMOG/Spanish adaptation of SMOG scores showed lower reading difficulty for Spanish, with few websites exceeding sixth grade (1.7% and 0% for English and Spanish, respectively). CONCLUSIONS: Online BC resources have reading difficulty levels that exceed the recommended sixth grade, although these results vary depending on readability framework. Efforts should be made to establish readability standards that can be translated into Spanish to enhance accessibility for this patient population.

7.
Plast Reconstr Surg Glob Open ; 12(8): e6090, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39188962

RESUMEN

Background: Geographic information systems are powerful tools for characterizing the geospatial factors influencing access to care. As patients with cleft lip and/or palate (CL/P) require long-term care, with numerous operations and therapies, access to timely, quality care is extremely important. This study uses population level analysis and geographic information systems to identify United States counties with limited access to American Cleft Palate Association-approved cleft teams. Methods: Natality data were queried from the National Vital Statistics System. Population and geographic data were obtained from the US Census Bureau. The Social Vulnerability Index (SVI) was utilized to account for social inequality. Total births with CL/P, population estimates, SVI, distance to the nearest center, and total centers within 50 km were used to generate the cleft care demand index (CCDI). Results: Ninety-two counties had CCDIs between 66.7 and 100. The highest scoring county, Hidalgo County, Texas, had 62 births with CL/P, population estimate of 888,367 persons, distance to the nearest cleft center of 368.4 km, and SVI of 0.99. Conclusions: This study demonstrates the power of geographic information systems for identifying areas with limited access to approved cleft teams. The CCDI measures cleft burden, socioeconomic disadvantage, and geographic barriers to quantify the demand for approved cleft care in each county. Utilizing these scores can help direct future interventions, outreach efforts, and cleft care center planning.

9.
Chem Sci ; 15(28): 11108-11121, 2024 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-39027298

RESUMEN

Tracking gene expression in deep tissues requires genetic reporters that can be unambiguously detected using tissue penetrant techniques. Magnetic resonance imaging (MRI) is uniquely suited for this purpose; however, there is a dearth of reporters that can be reliably linked to gene expression with minimal interference from background tissue signals. Here, we present a conceptually new method for generating background-subtracted, drug-gated, multiplex images of gene expression using MRI. Specifically, we engineered chemically erasable reporters consisting of a water channel, aquaporin-1, fused to destabilizing domains, which are stabilized by binding to cell-permeable small-molecule ligands. We showed that this approach allows for highly specific detection of gene expression through differential imaging. In addition, by engineering destabilized aquaporin-1 variants with orthogonal ligand requirements, it is possible to distinguish distinct subpopulations of cells in mixed cultures. Finally, we demonstrated this approach in a mouse tumor model through differential imaging of gene expression with minimal background.

10.
Ann Surg Oncol ; 31(11): 7445-7458, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39012456

RESUMEN

BACKGROUND: Palpable nodes were exclusionary in American College of Surgeons Oncology Group (ACOSOG) Z0011, while SINODAR-ONE excluded those with positive axillary nodes by palpation and ultrasound. To determine whether clinical nodal status should be exclusionary in those fulfilling pathologic criteria for ACOSOG Z0011 and similar trials, this study analyzed the accuracy and implications of clinical nodal positivity. METHODS: Patients ≥ 18 years old with cT1-T2, cN0-cN1, M0 breast cancer were identified in the National Cancer Database between 2004 and 2019. Subset characteristics of cN1 and cN0 were compared with respect to final pathologic nodal status and overall survival (OS). RESULTS: Of 57,823 patients identified, 77.0% were cT1 and 23.0% were cT2. Of the 93.9% of patients who were staged as cN0, 16.7% were pN1; of the remaining 6.1% staged as cN1, 9.6% were found to be pN0. Among cN1/pN0 patients, 14.9% underwent axillary dissection without sentinel node biopsy. There was no difference in adjusted OS for patients staged as cN0 versus cN1 who were found to be pN1 (HR 1.13, 95% CI 0.93-1.37, p = 0.22), a finding that persisted on subset analysis in those with two positive nodes (HR 0.91, 95% CI 0.62-1.33, p = 0.63). CONCLUSIONS: Clinical nodal stage does not affect OS in pN1 patients. Clinical nodal assessment can both overstage patients and result in unnecessary axillary surgery. These data suggest that cN1 patients who are otherwise candidates for a Z0011-like paradigm should still be considered eligible. Their final candidacy should be determined by surgical lymph node pathology and not preoperative clinical status.


Asunto(s)
Neoplasias de la Mama , Escisión del Ganglio Linfático , Ganglios Linfáticos , Humanos , Femenino , Persona de Mediana Edad , Ganglios Linfáticos/patología , Ganglios Linfáticos/cirugía , Neoplasias de la Mama/patología , Neoplasias de la Mama/cirugía , Anciano , Tasa de Supervivencia , Estudios de Seguimiento , Palpación , Axila , Metástasis Linfática , Pronóstico , Biopsia del Ganglio Linfático Centinela , Adulto , Estadificación de Neoplasias , Ensayos Clínicos como Asunto , Estudios Retrospectivos
11.
Ann Surg Oncol ; 31(11): 7498-7507, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-38976159

RESUMEN

BACKGROUND: Routine sentinel lymphadenectomy (SLNB) for early-stage HR+/HER2- breast cancer in women ≥70 is discouraged by Choosing Wisely, but whether SLNB can be routinely omitted in women ≥70 with DCIS undergoing mastectomy is unclear. This study aims to evaluate rates of axillary surgery and nodal positivity (pN+) in this population to determine the impact of axillary surgery on treatment decisions. METHODS: Females ≥70 with DCIS undergoing mastectomy were identified from the National Cancer Database (2012-2020). The rate of upstaging to invasive cancer (≥pT1) or pN+ was assessed. Subset analyses were conducted for ER+ patients. Adjuvant therapies were evaluated among ≥pT1 patients after stratifying by nodal status. RESULTS: Of 9,030 patients, 1,896 (21%) upstaged to ≥pT1. Axillary surgery was performed in 86% of patients, predominantly sentinel lymphadenectomy (SLNB, 65%). Post hoc application of Choosing Wisely criteria demonstrated that 93% of the entire cohort and 97% of ER+ DCIS patients could have avoided axillary surgery. Nodal positivity was 0.3% among those who didn't upstage, and 12% among those upstaging to ≥pT1, with <2% having pN2-3 disease, irrespective of receptor subtype. Node-positive patients had higher adjuvant therapy usage, but there was no recommendation for adjuvant chemotherapy or radiation for 71% and 66% of pN+ patients, respectively. CONCLUSIONS: Axillary surgery can be omitted for most patients ≥70 undergoing mastectomy for ER+ DCIS, aligning with recommendations for invasive cancer, and omission can be considered in those with ER- disease. Future guidelines incorporating preoperative imaging, as in the SOUND trial, may aid in identifying patients benefiting from axillary surgery.


Asunto(s)
Axila , Neoplasias de la Mama , Carcinoma Intraductal no Infiltrante , Escisión del Ganglio Linfático , Mastectomía , Biopsia del Ganglio Linfático Centinela , Humanos , Femenino , Neoplasias de la Mama/cirugía , Neoplasias de la Mama/patología , Carcinoma Intraductal no Infiltrante/cirugía , Carcinoma Intraductal no Infiltrante/patología , Anciano , Anciano de 80 o más Años , Estudios de Seguimiento , Pronóstico , Carcinoma Ductal de Mama/cirugía , Carcinoma Ductal de Mama/patología , Metástasis Linfática , Ganglios Linfáticos/patología , Ganglios Linfáticos/cirugía
12.
Ann Surg Oncol ; 31(11): 7303-7311, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39031257

RESUMEN

INTRODUCTION: Medicare significantly influences reimbursement rates, setting a standard that impacts private insurance policies. Despite declining rates in various specialties, the magnitude of these trends has not been examined in breast surgery. This study examines Medicare reimbursement trends for breast surgery operations. METHODS: Data for 10 breast operations from 2003 to 2023 were collected from the Medicare Physician Fee Look-Up Tool and yearly reimbursement was computed using the conversion factor. The year-to-year percentage change in reimbursement was calculated, and the overall median change was compared with the consumer price index (CPI) for inflation evaluation. All data were adjusted to 2023 United States dollars. The compound annual growth rate (CAGR) was calculated using inflation-adjusted data. RESULTS: Over the study period, reimbursement for the 10 breast operations had a mean unadjusted percentage increase of + 25.17%, while the CPI increased by 69.15% (p < 0.001). However, after adjustment, overall reimbursement decreased by - 20.70%. Only two operations (lumpectomy and simple mastectomy) saw increased inflation-adjusted Medicare reimbursement (+ 0.37% and + 3.58%, respectively). The CAGR was - 1.54% overall but remained positive for the same two operations (+ 0.02% and + 0.18%, respectively). Based on these findings, breast surgeons were estimated to be reimbursed $107,605,444 less in 2023 than if rates had kept pace with inflation over the past decade. CONCLUSION: Inflation-adjusted Medicare reimbursement rates for breast surgeries have declined from 2003 to 2023. This downward trend may strain resources, potentially leading to compromises in care quality. Surgeons, administrators, and policymakers must take proactive measures to address these issues and ensure the ongoing accessibility and quality of breast surgery.


Asunto(s)
Neoplasias de la Mama , Mastectomía , Medicare , Humanos , Estados Unidos , Medicare/economía , Femenino , Neoplasias de la Mama/cirugía , Neoplasias de la Mama/economía , Mastectomía/economía , Mecanismo de Reembolso/economía , Reembolso de Seguro de Salud/economía , Pronóstico , Estudios de Seguimiento
14.
Transl Vis Sci Technol ; 13(6): 11, 2024 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-38888288

RESUMEN

Purpose: To report on cases of unilateral perimacular atrophy after treatment with voretigene neparvovec-rzyl, in the setting of previous contralateral eye treatment with a different viral vector. Design: Single-center, retrospective chart review. Methods: In this case series, four patients between the ages of six and 11 years old with RPE65-related retinopathy were treated unilaterally with rAAV2-CB-hRPE65 as part of a gene augmentation clinical trial (NCT00749957). Six to 10 years later the contralateral eyes were treated with the Food and Drug Administration-approved drug, voretigene neparvovec-rzyl. Best-corrected visual acuity (BCVA), fundus photos, ocular coherence tomography, two-color dark-adapted perimetry, full field stimulus threshold testing (FST), and location of subretinal bleb and chorioretinal atrophy were evaluated. Results: Three out of four patients showed unilateral perimacular atrophy after treatment with voretigene, ranging from five to 22 months after treatment. Areas of robust visual field improvement were followed by areas of chorioretinal atrophy. Despite perimacular changes, BCVA, FST, and subjective improvements in vision and nyctalopia were maintained. Perimacular atrophy was not observed in the first eye treated with the previous viral vector. Conclusions: We observed areas of robust visual field improvement followed by perimacular atrophy in voretigene treated eyes, as compared to the initially treated contralateral eyes. Translational Relevance: Caution is advised when using two different viral vectors between eyes in gene therapy. This may become an important issue in the future with increasing gene therapy clinical trials for inherited retinal dystrophies.


Asunto(s)
Terapia Genética , Vectores Genéticos , Tomografía de Coherencia Óptica , Agudeza Visual , cis-trans-Isomerasas , Humanos , Estudios Retrospectivos , Vectores Genéticos/genética , Terapia Genética/métodos , Masculino , Femenino , Niño , cis-trans-Isomerasas/genética , Dependovirus/genética , Atrofia , Campos Visuales
16.
Semin Plast Surg ; 38(2): 133-144, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38746705

RESUMEN

Despite advancements in pediatric burn care, the profound hypermetabolic response associated with severe burns remains a multifaceted challenge throughout the continuum of care. Understanding the various physiologic disturbances that constitute hypermetabolism is crucial for a thorough evaluation and for implementing appropriate surgical and nonsurgical interventions. In this article, we describe the pathophysiology and treatment of hypermetabolism in pediatric burn patients with a focus on reducing resting energy requirements, minimizing infection, and optimizing nutrition for patients undergoing frequent surgical intervention.

17.
Inorg Chem ; 63(22): 10221-10229, 2024 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-38780069

RESUMEN

The reaction of equimolar trimethylsilyldiazomethyllithium (LiTMSD) with high spin (S = 2) PhB(AdIm)3FeCl (PhB(AdIm)3- = tris(3-adamantylimidazol-2-ylidene)phenylborate) affords the corresponding N-nitrilimido complex PhB(AdIm)3Fe-N═N═C(SiMe3). This complex can be converted to the thermodynamically more favorable C-isocyanoamido isomer PhB(AdIm)3Fe-C═N═N(SiMe3) by reaction with an additional equivalent of LiTMSD. While the iron(II) complexes are four-coordinate, the diazomethane is bound side-on in the iron(I) congener PhB(AdIm)3Fe(N,N'-κ2-N2C(H)Si(CH3)3). The latter complex adopts high spin (S = 3/2) ground state and features an unusually weak C-H bond. Photolysis of the iron(II) complexes induces N═N bond cleavage, with the iron(II) cyanide PhB(AdIm)3Fe-C≡N and iron(IV) nitride PhB(AdIm)3Fe≡N complexes being the major products of the reaction. The same products are obtained when the iron(I) complex is photolyzed or treated with a fluoride source. The trimethylsilyldiazomethane-derived ligand disassembly reactions are contrasted with those observed for related tris(carbene)amine complexes.

18.
J Surg Res ; 300: 93-101, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38805846

RESUMEN

INTRODUCTION: Patients use the internet to learn more about health conditions. Non-English-speaking patients may face additional challenges. The quality of online breast cancer information, the most common cancer in women, is uncertain. This study aims to examine the quality of online breast cancer information for English and non-English-speaking patients. METHODS: Three search engines were queried using the terms: "how to do a breast examination," "when do I need a mammogram," and "what are the treatment options for breast cancer" in English, Spanish, and Chinese. For each language, 60 unique websites were included and classified by type and information source. Two language-fluent reviewers evaluated website quality using the Journal of American Medical Association benchmark criteria (0-4) and the DISCERN tool (1-5), with higher scores representing higher quality. Scores were averaged for each language. Health On the Net code presence was noted. Inter-rater reliability between reviewers was assessed. RESULTS: English and Spanish websites most commonly originated from US sources (92% and 80%, respectively) compared to Chinese websites (33%, P < 0.001). The most common website type was hospital-affiliated for English (43%) and foundation/advocacy for Spanish and Chinese (43% and 45%, respectively). English websites had the highest and Chinese websites the lowest mean the Journal of American Medical Association (2.2 ± 1.4 versus 1.0 ± 0.8, P = 0.002) and DISCERN scores (3.5 ± 0.9 versus 2.3 ± 0.6, P < 0.001). Health On the Net code was present on 16 (8.9%) websites. Inter-rater reliability ranged from moderate to substantial agreement. CONCLUSIONS: The quality of online information on breast cancer across all three languages is poor. Information quality was poorest for Chinese websites. Improvements to enhance the reliability of breast cancer information across languages are needed.


Asunto(s)
Neoplasias de la Mama , Internet , Humanos , Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/terapia , Femenino , Multilingüismo , Información de Salud al Consumidor/normas , Información de Salud al Consumidor/estadística & datos numéricos , Lenguaje , Traducción
19.
J Surg Res ; 299: 217-223, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38776577

RESUMEN

INTRODUCTION: DESTINY B04 provided clinical meaning to a new classification of human epidermal growth factor 2 (HER2) expression in breast cancer: HER2-low. Patients with germline breast cancer type 1 gene pathogenic variants (gBRCA1) often develop triple negative breast cancer (TNBC), but the proportion who could be classified as HER2-low and qualify for an additional targeted therapy option is unknown. This study aims to characterize the proportion of gBRCA1 or germline breast cancer type 2 gene pathogenic variants patients for whom these novel targeted therapies may be an option. METHODS: We performed a retrospective chart review of patients with gBRCA1/2 treated at our institution for invasive breast cancer from 2000 to 2021. Synchronous or metachronous contralateral breast cancers were recorded separately. HER2 status was determined by immunohistochemistry and fluorescence in situ hybridization. We excluded patients without complete HER2 data. RESULTS: Among the 95 breast cancers identified in our cohort of 85 gBRCA1/2 patients, 41 (43%) were TNBC, 38 (40%) were hormone receptor positive (HR+)/HER2-negative, and 16 (17%) were HER2-positive based on standard conventions. We found that 82% of the HR+/HER2-cancers and 66% of TNBCs would be reclassified as HER2-low. After stratifying by BRCA gene status, 64% of cancers in patients with gBRCA1 and 58% of cancers in patients with germline breast cancer type 2 gene pathogenic variants were HER2-low. CONCLUSIONS: A significant portion of gBRCA1/2 patients who were previously diagnosed with TNBC or HR+/HER2- breast cancer would now be classified as HER2-low and could be considered for the use of trastuzumab deruxtecan in the metastatic setting. Outcome differences from therapy changes in this cohort should now be assessed.


Asunto(s)
Proteína BRCA1 , Proteína BRCA2 , Terapia Molecular Dirigida , Receptor ErbB-2 , Humanos , Femenino , Estudios Retrospectivos , Receptor ErbB-2/genética , Receptor ErbB-2/metabolismo , Receptor ErbB-2/análisis , Persona de Mediana Edad , Adulto , Proteína BRCA1/genética , Proteína BRCA2/genética , Anciano , Terapia Molecular Dirigida/métodos , Neoplasias de la Mama Triple Negativas/genética , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico , Mutación de Línea Germinal , Neoplasias de la Mama/genética , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología
20.
Bioconjug Chem ; 35(6): 744-749, 2024 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-38809040

RESUMEN

Bioconjugation of polymers to proteins is a method to impart improved stability and pharmacokinetic properties to biologic systems. However, the precise effects of polymer architecture on the resulting bioconjugates are not well understood. Particularly, cyclic polymers are known to possess unique features such as a decreased hydrodynamic radius when compared to their linear counterparts of the same molecular weight, but have not yet been studied. Here, we report the first bioconjugation of a cyclic polymer, poly(ethylene glycol) (PEG), to a model protein, T4 lysozyme, containing a single engineered cysteine residue (V131C). We compare the stability and activity of this conjugate with those of a linear PEG-T4 lysozyme analogue of similar molecular weight. Furthermore, we used molecular dynamics (MD) simulations to determine the behavior of the polymer-protein conjugates in solution. We introduce cyclic polymer-protein conjugates as potential candidates for the improvement of biologic therapeutics.


Asunto(s)
Simulación de Dinámica Molecular , Muramidasa , Polietilenglicoles , Polietilenglicoles/química , Muramidasa/química , Bacteriófago T4/enzimología
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