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1.
Artigo em Inglês | MEDLINE | ID: mdl-38862695

RESUMO

OPINION STATEMENT: Anaplastic thyroid cancer presents formidable challenges, particularly in cases of recurrence or metastasis. Timely BRAF V600E testing is imperative at diagnosis, initially through immunohistochemistry, followed by comprehensive genomic profiling encompassing genes such as NTRK, RET, ALK, and assessment of tumor mutation burden (TMB). FDA-approved treatment options include dabrafenib and trametinib for patients with BRAF mutations, while those exhibiting high TMB may benefit from pembrolizumab. Further therapeutic decisions hinge upon mutational profile, urgency of response required, airway integrity, and access to targeted therapies There is growing use of immunotherapy for ATC based on published reports of activity, but currently there is no FDA approved agent for ATC. The off-label utilization of "precision medicine" combinations imposes a considerable financial strain, underscoring the necessity for further clinical trials to elucidate promising therapeutic avenues for this orphan disease. There is a pressing need for the development and support of clinical trials investigating genomically driven and immune-based therapies for anaplastic thyroid cancer.

2.
Nano Lett ; 23(17): 7767-7774, 2023 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-37487140

RESUMO

The deep space's coldness (∼4 K) provides a ubiquitous and inexhaustible thermodynamic resource to suppress the cooling energy consumption. However, it is nontrivial to achieve subambient radiative cooling during daytime under strong direct sunlight, which requires rational and delicate photonic design for simultaneous high solar reflectivity (>94%) and thermal emissivity. A great challenge arises when trying to meet such strict photonic microstructure requirements while maintaining manufacturing scalability. Herein, we demonstrate a rapid, low-cost, template-free roll-to-roll method to fabricate spike microstructured photonic nanocomposite coatings with Al2O3 and TiO2 nanoparticles embedded that possess 96.0% of solar reflectivity and 97.0% of thermal emissivity. When facing direct sunlight in the spring of Chicago (average 699 W/m2 solar intensity), the coatings show a radiative cooling power of 39.1 W/m2. Combined with the coatings' superhydrophobic and contamination resistance merits, the potential 14.4% cooling energy-saving capability is numerically demonstrated across the United States.

3.
Lancet Oncol ; 24(2): 175-186, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36681089

RESUMO

BACKGROUND: Anaplastic thyroid cancer is a rare and aggressive cancer with no standard radiotherapy-based local treatment. Based on data suggesting synergy between pazopanib and paclitaxel in anaplastic thyroid cancer, NRG Oncology did a double-blind, placebo-controlled, randomised phase 2 clinical trial comparing concurrent paclitaxel and intensity-modulated radiotherapy (IMRT) with the addition of pazopanib or placebo with the aim of improving overall survival in this patient population. METHODS: Eligible patients were aged 18 years or older with a pathological diagnosis of anaplastic thyroid cancer, any TNM stage, Zubrod performance status of 0-2, no recent haemoptysis or bleeding, and no brain metastases. Patients were enrolled from 34 centres in the USA. Initially, a run-in was done to establish safety. In the randomised phase 2 trial, patients in the experimental group (pazopanib) received 2-3 weeks of weekly paclitaxel (80 mg/m2) intravenously and daily pazopanib suspension 400 mg orally followed by concurrent weekly paclitaxel (50 mg/m2), daily pazopanib (300 mg), and IMRT 66 Gy given in 33 daily fractions (2 Gy fractions). In the control group (placebo), pazopanib was replaced by matching placebo. Patients were randomly assigned (1:1) to the two treatment groups by permuted block randomisation by NRG Oncology with stratification by metastatic disease. All investigators, patients, and funders of the study were masked to group allocation. The primary endpoint was overall survival in the intention-to-treat population. Safety was assessed in all patients who received at least one dose of study treatment. This trial is registered with Clinicaltrials.gov, NCT01236547, and is complete. FINDINGS: The safety run-showed the final dosing regimen to be safe based on two out of nine participants having adverse events of predefined concern. Between June 23, 2014, and Dec 30, 2016, 89 patients were enrolled to the phase 2 trial, of whom 71 were eligible (36 in the pazopanib group and 35 in the placebo group; 34 [48%] males and 37 [52%] females). At the final analysis (data cutoff March 9, 2020), with a median follow-up of 2·9 years (IQR 0·002-4·0), 61 patients had died. Overall survival was not significantly improved with pazopanib versus placebo, with a median overall survival of 5·7 months (95% CI 4·0-12·8) in the pazopanib group versus 7·3 months (4·3-10·6) in the placebo group (hazard ratio 0·86, 95% CI 0·52-1·43; one-sided log-rank p=0·28). 1-year overall survival was 37·1% (95% CI 21·1-53·2) in the pazopanib group and 29·0% (13·2-44·8) in the placebo group. The incidence of grade 3-5 adverse events did not differ significantly between the treatment groups (pazopanib 88·9% [32 of 36 patients] and placebo 85·3% [29 of 34 patients]; p=0·73). The most common clinically significant grade 3-4 adverse events in the 70 eligible treated patients (36 in the pazopanib group and 34 in the placebo group) were dysphagia (13 [36%] vs 10 [29%]), radiation dermatitis (8 [22%] vs 13 [38%]), increased alanine aminotransferase (12 [33%] vs none), increased aspartate aminotransferase (eight [22%] vs none), and oral mucositis (five [14%] vs eight [24%]). Treatment-related serious adverse events were reported for 16 (44%) patients on pazopanib and 12 (35%) patients on placebo. The most common serious adverse events were dehydration and thromboembolic event (three [8%] each) in patients on pazopanib and oral mucositis (three [8%]) in those on placebo. There was one treatment-related death in each group (sepsis in the pazopanib group and pneumonitis in the placebo group). INTERPRETATION: To our knowledge, this study is the largest randomised anaplastic thyroid cancer study that has completed accrual showing feasibility in a multicenter NCI National Clinical Trials Network setting. Although no significant improvement in overall survival was recorded in the pazopanib group, the treatment combination was shown to be feasible and safe, and hypothesis-generating data that might warrant further investigation were generated. FUNDING: National Cancer Institute and Novartis.


Assuntos
Quimiorradioterapia , Carcinoma Anaplásico da Tireoide , Neoplasias da Glândula Tireoide , Feminino , Humanos , Masculino , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Método Duplo-Cego , Paclitaxel/efeitos adversos , Carcinoma Anaplásico da Tireoide/tratamento farmacológico , Carcinoma Anaplásico da Tireoide/terapia , Neoplasias da Glândula Tireoide/tratamento farmacológico , Neoplasias da Glândula Tireoide/radioterapia
4.
Surg Innov ; 30(4): 529-532, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36416642

RESUMO

Background/need. Office-based sedation has become increasingly commonplace in dental offices in recent years, allowing for practitioners to provide broader scope of care for their patients. Maintaining high standards of safety is of utmost importance when sedation is utilized in the office-based setting, especially for patients deemed at a higher-risk for intraoperative airway obstruction. This demographic includes but is not limited to individuals with a medical history significant for obstructive sleep apnea, chronic obstructive pulmonary disease, and morbid obesity. Presently, a wide variety of airway devices exist for use in the event of airway obstruction. However, in the context of oral and maxillofacial surgery, placement of these devices can encroach upon the surgical field, extending the perioperative period and putting the patient at greater long-term risk for maintaining adequate oxygenation. Methodology. The authors describe a preliminary technique trialed in our offices which utilizes a size 5.0 endotracheal tube (5OET) as an adjunct supraglottic airway to help mitigate the issue of oxygen saturation maintenance, as well as unimpeded access to the oral cavity. Implementation of the device requires identifying appropriate candidates during preoperative screening and placing the device through the nare and securing it above the glottis. Device Description. The 'tube kit' is comprised of a standard size straight 5.0 cuffed oral ETT, a 5-mL syringe for inflation of the cuff post insertion, lubricant, flex extension tubing, end tidal sampling line for capnography, tape for securement of the 5OET, and an anesthesia breathing circuit. Optional equipment pieces include an elbow connecter and a foam piece for comfort. Results/Current Status. Preliminary results have demonstrated oxygen saturations maintained above 98% when the 5OET is placed preoperatively. Continued use of the trial device will inform the development of a tube by our clinicians, and its efficacy will be studied in our offices. The next steps will be to start developing a pilot cuff that will be submitted for patent approval after its use in IRB-approved clinical studies.


Assuntos
Obstrução das Vias Respiratórias , Anestesia , Apneia Obstrutiva do Sono , Cirurgia Bucal , Humanos , Intubação Intratraqueal , Apneia Obstrutiva do Sono/cirurgia
5.
Invest New Drugs ; 40(4): 782-788, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35435625

RESUMO

BACKGROUND: Tarloxotinib, a hypoxia-activated prodrug of an irreversible pan-ErbB tyrosine kinase inhibitor, represents a novel therapeutic which exploits the tumor-specific hypoxic environment as a mechanism for tumor-specific targeting. This study evaluated the safety and activity of tarloxotinib in recurrent or metastatic (R/M) cutaneous (CSCC) or head and neck squamous cell carcinoma (HNSCC). METHODS: This was a phase II two-stage multi-centre study for patients with R/M HNSCC or CSCC. All patients received tarloxotinib 150 mg/m2 on days 1,8,15 and 22 in a 28-day cycle. Stage 1 enrolled patients in three cohorts: p16-negative HNSCC, p16-positive oropharyngeal SCC, and CSCC. In order for a cohort to proceed to stage 2 a minimum response rate of 5% was required. RESULTS: 30 patients were enrolled: 23% were female with median age of 63.3 years. The median duration of follow-up was 20 weeks. The median progression-free survival was 2.0 months (95%CI 1.8-3.4) and median overall survival 5.7 months (95%CI 3.6-8.0). Treatment was well tolerated. The objective response rate was 3% with one patient with CSCC having a partial response. CONCLUSIONS: Hypoxia-activated prodrugs represent a novel approach to cancer treatment, however, no clinically meaningful benefit for tarloxotinib in R/M HNSCC or CSCC was identified in this study. TRIAL REGISTRATION NUMBER: NCT02449681 (May 20, 2015).


Assuntos
Carcinoma de Células Escamosas , Neoplasias de Cabeça e Pescoço , Pró-Fármacos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma de Células Escamosas/patologia , Feminino , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Humanos , Hipóxia/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/patologia , Pró-Fármacos/efeitos adversos , Inibidores de Proteínas Quinases/efeitos adversos , Carcinoma de Células Escamosas de Cabeça e Pescoço/tratamento farmacológico
6.
Biomacromolecules ; 23(11): 4696-4708, 2022 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-36198084

RESUMO

Injectable collagen-based hydrogels offer great promise for tissue engineering and regeneration, but their use is limited by poor mechanical strength. Herein, we incorporate tannic acid (TA) to tailor the rheology of the corresponding hydrogels while simultaneously adding the therapeutic benefits inherent to this polyphenolic component. TA in the solution form and needle-shaped TA microparticles are combined with collagen and the respective systems studied for their time-dependent sol-gel transitions (from storage to body temperatures, 4-37 °C) as a function of TA concentration. Compared to systems incorporating TA microparticles, those with dissolved TA, applied at a similar concentration, generate a less significant enhancement of the elastic modulus. Premature gelation at a low temperature and associated colloidal arrest of the system are proposed as a main factor explaining this limited performance. A higher yield stress (elastic stress method) is determined for systems loaded with TA microparticles compared to the system with dissolved TA. These results are interpreted in terms of the underlying interactions of TA with collagen, as probed by spectroscopy and isothermal titration calorimetry. Importantly, hydrogels containing TA microparticles show high cell viability (human dermal fibroblasts) and comparative cellular activity relative to the collagen-only hydrogel. Overall, composite hydrogels incorporating TA microparticles demonstrate a new, simple, and better-performance alternative to cell culturing and difficult implantation scenarios.


Assuntos
Hidrogéis , Taninos , Humanos , Hidrogéis/química , Colágeno/química , Módulo de Elasticidade , Reologia
7.
Langmuir ; 37(38): 11242-11250, 2021 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-34520662

RESUMO

The development of new materials emphasizes greater use of sustainable and eco-friendly resources, including those that take advantage of the unique properties of nanopolysaccharides. Advances in this area, however, necessarily require a thorough understanding of interactions with water. Our contribution to this important topic pertains to the swelling behavior of partially deacetylated nanochitin (NCh), which has been studied here by quartz crystal microgravimetry. Ultrathin films of NCh supported on gold-coated resonators have been equilibrated in aqueous electrolyte solutions (containing NaF, NaCl, NaBr, NaNO3, Na2SO4, Na2SO3, or Na3PO4) at different ionic strengths. As anticipated, NCh displays contrasting swelling/deswelling responses, depending on the ionic affinities and valences of the counterions. The extent of water uptake induced by halide anions, for instance, follows a modified Hofmeister series with F- producing the highest swelling. In marked contrast, Cl- induces film dehydration. We conclude that larger anions promote deswelling such that water losses increase with increasing anion valence. Results such as the ones reported here are critical to ongoing efforts designed to dry chitin nanomaterials and develop bio-based and sustainable materials, including particles, films, coatings, and other nanostructured assemblies, for various devices and applications.


Assuntos
Quartzo , Água , Ânions , Íons , Pressão Osmótica
8.
Oncologist ; 25(11): 954-962, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32812320

RESUMO

BACKGROUND: Matrix metalloproteinase 9 (MMP9) expression in the tumor microenvironment is implicated in multiple protumorigenic processes. Andecaliximab (GS-5745), a monoclonal antibody targeting MMP9 with high affinity and selectivity, was evaluated in combination with gemcitabine and nab-paclitaxel in patients with advanced pancreatic adenocarcinoma. PATIENTS AND METHODS: This phase I study was completed in two parts: part A was a dose-finding, monotherapy phase that enrolled patients with advanced solid tumors, and part B examined andecaliximab in combination with chemotherapy in specific patient cohorts. In the cohort of patients with pancreatic adenocarcinoma (n = 36), andecaliximab 800 mg every 2 weeks was administered in combination with gemcitabine and nab-paclitaxel. Patients were treated until unacceptable toxicity, withdrawal of consent, disease progression, or death. Efficacy, safety, and biomarker assessments were performed. RESULTS: Andecaliximab combined with gemcitabine and nab-paclitaxel appeared to be well tolerated and did not demonstrate any unusual toxicities in patients with pancreatic adenocarcinoma. The most common treatment-emergent adverse events were fatigue (75.0%), alopecia (55.6%), peripheral edema (55.6%), and nausea (50.0%). Median progression-free survival was 7.8 months (90% confidence interval, 6.9-11.0) with an objective response rate of 44.4% and median duration of response of 7.6 months. Maximal andecaliximab target binding, defined as undetectable, andecaliximab-free MMP9 in plasma, was observed. CONCLUSION: Andecaliximab in combination with gemcitabine and nab-paclitaxel demonstrates a favorable safety profile and clinical activity in patients with advanced pancreatic adenocarcinoma. IMPLICATIONS FOR PRACTICE: The combination of andecaliximab, a novel, first-in-class inhibitor of matrix metalloproteinase 9, with gemcitabine and nab-paclitaxel in patients with advanced pancreatic adenocarcinoma provided a median progression-free survival of 7.8 months and objective response rate of 44.4%. The majority of systemic biomarkers related to matrix metalloproteinase 9 activity and immune suppression increased at 2 months, whereas biomarkers related to tumor burden decreased. Although this study demonstrates promising results with andecaliximab plus chemotherapy in patients with advanced pancreatic adenocarcinoma, andecaliximab was not associated with a survival benefit in a phase III study in patients with advanced gastric/gastroesophageal junction carcinoma.


Assuntos
Adenocarcinoma , Neoplasias Pancreáticas , Adenocarcinoma/tratamento farmacológico , Albuminas , Anticorpos Monoclonais Humanizados , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Desoxicitidina/análogos & derivados , Humanos , Paclitaxel/uso terapêutico , Neoplasias Pancreáticas/tratamento farmacológico , Resultado do Tratamento , Microambiente Tumoral , Gencitabina
9.
Oncologist ; 25(8): e1242-e1245, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32400023

RESUMO

Immune-related adverse events induced by immune checkpoint inhibitor (ICI) therapy may affect diverse organ systems, including skeletal and cardiac muscle. ICI-associated myositis may result in substantial morbidity and occasional mortality. We present a case of a patient with advanced non-small cell lung cancer who developed grade 4 myositis with concurrent myocarditis early after initiation of anti-programmed death ligand 1 therapy (durvalumab). Autoantibody analysis revealed marked increases in anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase antibody levels that preceded clinical toxicity, and further increased during toxicity. Notably, the patient had a history of intolerable statin myopathy, which had resolved clinically after statin discontinuation and prior to ICI initiation. This case demonstrates a potential association between statin exposure, autoantibodies, and ICI-associated myositis.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Inibidores de Hidroximetilglutaril-CoA Redutases , Neoplasias Pulmonares , Miosite , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/efeitos adversos , Inibidores de Checkpoint Imunológico , Miosite/induzido quimicamente , Miosite/tratamento farmacológico
10.
Oncologist ; 25(5): e753-e757, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32167195

RESUMO

Immune checkpoint inhibitor (ICI)-induced immune-related adverse events (irAEs) may affect almost any organ system and occur at any point during therapy. Autoantibody analysis may provide insight into the mechanism, nature, and timing of these events. We report a case of ICI-induced late-onset Raynaud's-like phenomenon in a patient receiving combination immunotherapy. A 53-year-old woman with advanced non-small lung cancer received combination anti-cytotoxic T-lymphocyte antigen 4 and anti-programmed death 1 ICI therapy. She developed early (hypophysitis at 4 months) and late (Raynaud's at >20 months) irAEs. Longitudinal assessment of 124 autoantibodies was correlated with toxicity. Although autoantibody levels were generally stable for the first 18 months of therapy, shortly before the development of Raynaud's, a marked increase in multiple autoantibodies was observed. This case highlights the potential for delayed autoimmune toxicities and provides potential biologic insights into the dynamic nature of these events. KEY POINTS: A patient treated with dual anti-PD1 and anti-CTLA4 therapy developed Raynaud's-like signs and symptoms more than 18 months after starting therapy. In this case, autoantibody changes became apparent shortly before onset of clinical toxicity. This case highlights the potential for late-onset immune-related adverse events checkpoint inhibitors, requiring continuous clinical vigilance. The optimal duration of checkpoint inhibitor therapy in patients with profound and prolonged responses remains unclear.


Assuntos
Imunoterapia , Neoplasias Pulmonares , Autoanticorpos , Feminino , Humanos , Fatores Imunológicos , Imunoterapia/efeitos adversos , Pessoa de Meia-Idade
11.
Curr Opin Colloid Interface Sci ; 48: 121-136, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33013179

RESUMO

Climate changes, emerging species of plant pests, and deficits of clean water and arable land have made availability of food to the ever-increasing global population a challenge. Excessive use of synthetic pesticides to meet ever-increasing production needs has resulted in development of resistance in pest populations, as well as significant ecotoxicity, which has directly and indirectly impacted all life-forms on earth. To meet the goal of providing safe, sufficient, and high-quality food globally with minimal environmental impact, one strategy is to focus on targeted delivery of pesticides using eco-friendly and biodegradable carriers that are derived from naturally available materials. Herein, we discuss some of the recent approaches to use biodegradable matrices in crop protection, while exploring their design and efficiency. We summarize by discussing associated challenges with the existing approaches and future trends that can lead the world to more sustainable agricultural practices.

12.
Oncology ; 98(3): 179-185, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31846962

RESUMO

BACKGROUND: HPV-positive head and neck squamous cell carcinoma (HPV+ HNSCC) demonstrates favorable outcomes compared to HPV-negative SCC, but distant metastases (DM) still occur. The pattern of DM in HPV+ HNSCC is unclear. METHODS: 1,494 HNSCC patients were treated from 2006 to 2012. Recurrence time and metastatic sites in HPV+ HNSCC (Group 1) were compared to patients with HPV-negative/unknown cancers arising in the hypopharynx, larynx, or glottis (Group 2) as well as to patients with HPV-negative/unknown cancers in theoral cavity, oropharynx, hard palate, or tonsil (Group 3). RESULTS: 7/109 (6.4%) patients with HPV+ HNSCC developed DM. The median time to metastases was 11 months. At a median follow-up of 18-25 months, there was no difference in the overall rate of DM for the HPV+ HNSCC group compared to Group 2 (HPV-/unknown) (p = 0.21) and Group 3 (HPV-/unknown) (p = 0.13). There was a significant difference in the rate of DM to the lung in the HPV+ HNSCC group compared to Group 2 (HPV-/unknown) (p = 0.012) and Group 3 (HPV-/unknown) (p = 0.002). CONCLUSIONS: There was no observed difference in the time to development of DM between the HPV-/unknown and HPV+ HNSCC groups. However, the HPV+ HNSCC group showed a higher rate of DM to the lung compared to the HPV-/unknown -HNSCC group (p = 0.002).


Assuntos
Neoplasias de Cabeça e Pescoço/patologia , Neoplasias de Cabeça e Pescoço/virologia , Infecções por Papillomavirus/virologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/secundário , Carcinoma de Células Escamosas de Cabeça e Pescoço/virologia , Idoso , Progressão da Doença , Feminino , Neoplasias de Cabeça e Pescoço/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Infecções por Papillomavirus/diagnóstico , Infecções por Papillomavirus/terapia , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Carcinoma de Células Escamosas de Cabeça e Pescoço/terapia , Fatores de Tempo , Resultado do Tratamento
13.
Langmuir ; 36(36): 10830-10837, 2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32808787

RESUMO

Aqueous suspensions of cellulose nanocrystals (CNCs) can spontaneously form a chiral nematic mesophase at a critical concentration (c*). Unfortunately, no current analytical technique permits rapid detection of c*. Herein, we introduce a facile and accurate approach to assess c* rapidly (<2 h) from a small sample volume and compare our results with those obtained by conventional methods. Our strategy employs isothermal titration calorimetry (ITC) to measure the heat associated with interactions in the suspension, which can identify the onset of mesophase formation as the heat signature is sensitive to the suspension viscosity and thus capable of detecting small changes in the suspension environment. We measure c* for CNC samples differing in surface charge and aspect ratio, and find that both lower aspect ratios and higher surface charges increase c*. Our ITC results reveal the role of CNC interactions prior to the visual observation of mesophase formation and elucidate mesomorphic effects related to nanocrystals and their suspensions.

14.
Biomacromolecules ; 21(9): 3561-3570, 2020 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-32687338

RESUMO

Cellulosic nanomaterials constitute a topic of growing commercial interest for numerous applications, many of which demand a working knowledge of the rheology of the materials. We demonstrate here that aqueous suspensions of micro/nanofibrillated cellulose (MNFC) exhibit complex shear behavior governed primarily by fibrillar floc dynamics. Regimes corresponding to structure formation, persistence, and breakdown are quantitatively differentiated. We assess the recovery of the network structure as a function of the applied breakdown conditions and identify critical conditions that characterize the floc dynamics as isotropic or anisotropic. A two-step yield behavior generates persistent anisotropic flocs that effectively prohibit recovery of the initial gel structure under certain conditions. Processing within this stress window entails a risk of generating heterogeneous, potentially irreproducible structures and properties. An in-depth understanding of the rheology of aqueous MNFC suspensions and their floc-dominated, rather than fibril-dominated, nature is critical to rationally tailoring properties through judicious selection of processing conditions.


Assuntos
Celulose , Nanoestruturas , Reologia , Suspensões , Água
15.
Soft Matter ; 16(37): 8602-8611, 2020 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-32845269

RESUMO

Nanomaterials are regularly added to crosslinkable polymers to enhance mechanical properties; however, important effects related to gelation behavior and crosslinking kinetics are often overlooked. In this study, we combine cellulose nanocrystals (CNCs) with a photoactive poly(vinyl alcohol) derivative, PVA-SbQ, to form photocrosslinked nanocomposite hydrogels. We investigate the rheology of PVA-SbQ with and without CNCs to decipher the role of each component in final property development and identify a critical CNC concentration (1.5 wt%) above which several changes in rheological behavior are observed. Neat PVA-SbQ solutions exhibit Newtonian flow behavior across all concentrations, while CNC dispersions are shear-thinning <6 wt% and gel at high concentrations. Combining semi-dilute entangled PVA-SbQ (6 wt%) with >1.5 wt% CNCs forms a percolated microstructure. In situ photocrosslinking experiments reveal how CNCs affect both the gelation kinetics and storage modulus (G') of the resulting hydrogels. The modulus crossover time increases after addition of up to 1.5 wt% CNCs, while no modulus crossover is observed >1.5 wt% CNCs. A sharp increase in G' is observed >1.5 wt% CNCs for fully-crosslinked networks due to favorable PVA-SbQ/CNC interactions. A percolation model is fitted to the G' data to confirm that mechanical percolation is maintained after photocrosslinking. A ∼120% increase in G' for 2.5 wt% CNCs (relative to neat PVA-SbQ) confirms that CNCs provide a reinforcing effect through the percolated microstructure formed from PVA-SbQ/CNC interactions. The results are testament to the ability of CNCs to significantly alter the storage moduli of crosslinked polymer gels at low loading fractions through percolation-induced reinforcement.

16.
Br J Cancer ; 120(1): 63-68, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30377338

RESUMO

BACKGROUND: Up to 40% of cancer patients on immune checkpoint inhibitors develop clinically significant immune-related adverse events (irAEs). The role of host immune status and function in predisposing patients to the development of irAEs remains unknown. METHODS: Sera from 65 patients receiving immune checkpoint inhibitors and 13 healthy controls were evaluated for 40 cytokines at pre-treatment, after 2-3 weeks and after 6 weeks and analysed for correlation with the development of irAEs. RESULTS: Of the 65 cancer patients enrolled, 55% were women; the mean age was 65 years and 98% received anti-PD1/PDL1 therapy. irAEs occurred in 35% of cases. Among healthy controls, cytokine levels were stable over time and lower than those in cancer patients at baseline. Significant increases in CXCL9, CXCL10, CXCL11 and CXCL13 occurred 2 weeks post treatment, and in CXCL9, CXCL10, CXCL11, CXCL13, IL-10 and CCL26 at 6 weeks post treatment. Patients who developed irAEs had lower levels of CXCL9, CXCL10, CXCL11 and CXCL19 at baseline and exhibited greater increases in CXCL9 and CXCL10 levels at post treatment compared to patients without irAEs. CONCLUSIONS: Patients who developed irAEs have lower baseline levels and greater post-treatment increases in multiple cytokine levels, suggesting that underlying immune dysregulation may be associated with heightened risk for irAEs.


Assuntos
Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/imunologia , Imunoterapia/efeitos adversos , Neoplasias/terapia , Idoso , Citocinas/genética , Citocinas/imunologia , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/imunologia , Neoplasias/patologia , Fatores de Risco
17.
Langmuir ; 35(1): 237-247, 2019 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-30525656

RESUMO

Aluminum trihydroxide/polydimethylsiloxane (ATH/PDMS) systems are often used as potting compounds in electronic assemblies to guard the electronics from shock, vibration, corrosive agents, and moisture. In this study, we use dynamic rheology and confocal/optical microscopy to understand the dramatic effects miniscule levels of water have on the microstructure and corresponding rheological behavior of PDMS filled with ATH. In the absence of water, PDMS containing 20 wt % ATH readily flows, exhibiting viscoelastic behavior with some weak particle flocculation. However, the addition of only 0.045 wt % water to the system results in the formation of a sample-spanning, self-supporting physical gel that exhibits an elastic modulus ( G') five orders of magnitude higher than the water-free system. A structure formation mechanism consisting of hydration layer formation followed by interparticle water bridging has been proposed to explain the observed behavior. Recovery of the original viscoelastic fluid is demonstrated by adding molecular sieves (e.g., zeolites) to the fully flocculated system. The recovery can likely be attributed to the adsorption of water by the sieves and the corresponding breakup of water bridges between the ATH particles. On the basis of the proposed mechanism, a variety of other polar and nonpolar solvents have been found to induce physical gelation in ATH/PDMS dispersions with gel modulus being related to the Hildebrand solubility parameter mismatch between the solvent and PDMS fluid.

18.
Chemphyschem ; 19(10): 1197-1204, 2018 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-29316144

RESUMO

Electrochemical monitoring of non-electroactive species requires a biosensor that is stable and selective, with sensitivity to physiological concentrations of targeted analytes. We have combined glucose oxidase-modified carbon-fiber microelectrodes with fast-scan cyclic voltammetry for real-time measurements of glucose fluctuations in brain tissue. Work presented herein quantitatively compares three approaches to enzyme immobilization on the microelectrode surface-physical adsorption, hydrogel entrapment, and entrapment in electrospun nanofibers. The data suggest that each of these methods can be used to create functional microbiosensors. Immobilization of glucose oxidase by physical adsorption generates a biosensor with poor sensitivity to glucose and unstable performance. Entrapment of glucose oxidase in poly(vinyl alcohol) nanofibers generates microbiosensors that are effective for glucose measurements over a large linear range, and that may be particularly useful when targeting glucose concentrations in excess of 3 mm, such as in blood. Hydrogel entrapment is the most effective in terms of sensitivity and stability. These microbiosensors can be used for simultaneous monitoring of glucose and dopamine in real time. The findings outlined herein should be applicable to other oxidase enzymes, and thus they are broadly important for the development of new tools for real-time measurements of fluctuating molecules that are not inherently electroactive.


Assuntos
Técnicas Biossensoriais , Carbono/química , Técnicas Eletroquímicas , Glucose Oxidase/metabolismo , Glucose/análise , Animais , Enzimas Imobilizadas , Masculino , Microeletrodos , Ratos , Ratos Sprague-Dawley , Fatores de Tempo
19.
Cancer ; 123(2): 273-282, 2017 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-27649421

RESUMO

BACKGROUND: To the authors' knowledge, the patterns of care for the radiotherapy-based treatment of patients with stage III to IVB oropharyngeal squamous cell carcinoma (OPSCC) are poorly defined. The objective of the current study was to characterize the use and predictors of chemotherapy with radiotherapy for this population using the National Cancer Database. METHODS: Patients in the National Cancer Database with AJCC (American Joint Committee on Cancer) stage III to IV OPSCC who were treated with radiotherapy between 2003 and 2012 were eligible for analysis. Treatment was defined as radiotherapy alone, concurrent chemoradiotherapy, or induction chemotherapy (IC). Multivariable regression with multilevel modeling was used to determine predictors of any chemotherapy use and, among patients receiving chemotherapy, the predictors of IC. RESULTS: The majority (90%) of the 30,875 eligible patients received chemotherapy, the majority of whom (71% of the total) were treated with definitive chemoradiotherapy; a sizeable percentage of patients received IC (19% of total). On multivariable regression, younger age, favorable comorbidity status, and more advanced tumor and lymph node disease were found to be independent predictors of any chemotherapy and IC use. Nonwhite patients (odds ratio [OR], 0.71; P<.0001), women (OR, 0.74; P<.0001), and individuals without private insurance were found to be significantly less likely to receive chemotherapy. Patients treated at higher-volume institutions were significantly less likely to receive IC (OR, 0.69; P = .0006). Human papillomavirus status did not appear to independently influence treatment choice. CONCLUSIONS: The vast majority of patients with stage III to IVB OPSCC who were treated with definitive radiotherapy received chemotherapy, which is consistent with high-level data and national recommendations. However, disparities with regard to race, sex, and insurance status emerged thereby requiring additional investigation. The frequent use of IC despite limited supportive evidence warrants research on physician and patient decision making and presents an opportunity to improve evidence-based treatment delivery. Cancer 2017;123:273-282. © 2016 American Cancer Society.


Assuntos
Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/radioterapia , Neoplasias Orofaríngeas/tratamento farmacológico , Neoplasias Orofaríngeas/radioterapia , Idoso , Carcinoma de Células Escamosas/patologia , Quimiorradioterapia/métodos , Feminino , Humanos , Linfonodos/efeitos dos fármacos , Linfonodos/patologia , Linfonodos/efeitos da radiação , Masculino , Pessoa de Meia-Idade , Terapia Neoadjuvante/métodos , Estadiamento de Neoplasias/métodos , Neoplasias Orofaríngeas/patologia , Papillomaviridae , Infecções por Papillomavirus/patologia , Infecções por Papillomavirus/virologia
20.
Cancer Invest ; 35(1): 23-31, 2017 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-27892728

RESUMO

Nab-paclitaxel might impact efficacy of radiation for head and neck (H&N) cancer. Nab-paclitaxel, cisplatin, cetuximab, and radiation were evaluated in patients with locally advanced head and neck cancer in this phase I/II trial. Median follow-up was 24 months for 34 patients. The maximum tolerated dose of nab-paclitaxel was 20 mg/m2 with 20 mg/m2 cisplatin and 250 mg/m2 cetuximab. The 2-year progression-free survival (PFS) was 60% (95% confidence interval (CI) 0.42, 0.78), local control 71% (95% CI 0.55, 0.87), and overall survival 68% (95% CI 0.50, 0.86). This is the first study evaluating these agents with radiation in humans, with similar 2-year PFS as historic control.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Carcinoma de Células Escamosas/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/radioterapia , Idoso , Albuminas/administração & dosagem , Albuminas/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Cetuximab/administração & dosagem , Cetuximab/uso terapêutico , Cisplatino/administração & dosagem , Cisplatino/uso terapêutico , Terapia Combinada , Feminino , Humanos , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Paclitaxel/administração & dosagem , Paclitaxel/uso terapêutico , Análise de Sobrevida , Resultado do Tratamento
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