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1.
Clin Lung Cancer ; 25(3): e161-e171, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38195320

RESUMO

BACKGROUND: Immune checkpoint inhibitor (ICI) consolidation following concurrent chemoradiotherapy (CRT) substantially improved progression free survival (PFS) and overall survival (OS) in the PACIFIC trial becoming the standard of care in locally-advanced, unresectable NSCLC. KRAS mutation may influence response to ICI. METHODS: In this single-institution, retrospective analysis, we compared treatment outcomes for patients with unresectable KRAS mutated (KRAS-mt) and wild-type (KRAS-wt) NSCLC treated with CRT between October 2017 and December 2021. Kaplan-Meier analysis was conducted comparing median progression free survival and median overall survival from completion of radiotherapy in all KRAS-mt patients and KRAS-G12C-mutated patients. Outcomes were also compared with and without ICI consolidation. RESULTS: Of 156 patients, 42 (26.9%) were KRAS-mt and 114 (73.1%) were KRAS-wt. Baseline characteristics differed only in histology; KRAS-mt NSCLC more likely to be adenocarcinoma. KRAS-mt patients had worse PFS (median 6.3 vs. 10.7 months, P = .041) but similar OS (median 23.1 vs. 27.3 months, P = .237). KRAS-mt patients were more likely to not receive ICI due to rapid disease progression post-CRT (23.8% vs. 4.4%, P = .007). Among patients who received ICI (n = 114), KRAS-mt was not associated with inferior PFS (8.1 vs. 11.9 months, P = .355) or OS (30.5 vs. 31.7 months, P = .692). KRAS-G12C patients (n = 22) had similar PFS and OS to other KRAS-mt. CONCLUSION: In one of the largest post-CRT KRAS-mt cohort published, KRAS-mt was associated with inferior PFS, largely due to rapid progression prior to ICI consolidation, but did not affect OS. Among those who received ICI consolidation, outcomes were comparable regardless of KRAS-mt status.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Quimiorradioterapia , Neoplasias Pulmonares , Mutação , Proteínas Proto-Oncogênicas p21(ras) , Humanos , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/terapia , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Feminino , Masculino , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/terapia , Neoplasias Pulmonares/mortalidade , Proteínas Proto-Oncogênicas p21(ras)/genética , Pessoa de Meia-Idade , Estudos Retrospectivos , Idoso , Quimiorradioterapia/métodos , Adulto , Anticorpos Monoclonais/uso terapêutico , Idoso de 80 Anos ou mais , Taxa de Sobrevida , Quimioterapia de Consolidação , Inibidores de Checkpoint Imunológico/uso terapêutico , Antineoplásicos Imunológicos/uso terapêutico , Resultado do Tratamento
2.
Eur Urol Oncol ; 2023 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-37926618

RESUMO

BACKGROUND: Guidelines recommend dual-energy x-ray absorptiometry (DXA) screening to assess fracture risk and benefit from antiresorptive therapy in men with metastatic hormone-sensitive prostate cancer (mHSPC) on androgen deprivation therapy (ADT). However, <30% of eligible patients undergo DXA screening. Biomechanical computed tomography (BCT) is a radiomic technique that measures bone mineral density (BMD) and bone strength from computed tomography (CT) scans. OBJECTIVE: To evaluate the (1) correlations between BCT- and DXA-assessed BMD, and (2) associations between BCT-assessed metrics and subsequent fracture. DESIGN, SETTING, AND PARTICIPANTS: A multicenter retrospective cohort study was conducted among patients with mHSPC between 2013 and 2020 who received CT abdomen/pelvis or positron emission tomography/CT within 48 wk before ADT initiation and during follow-up (48-96 wk after ADT initiation). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: We used univariate logistic regression to assess the associations between BCT measurements and the primary outcomes of subsequent pathologic and nonpathologic fractures. RESULTS AND LIMITATIONS: Among 91 eligible patients, the median ([interquartile range) age was 67 yr (62-75), 44 (48.4%) were White, and 41 (45.1%) were Black. During the median follow-up of 82 wk, 17 men (18.6%) developed a pathologic and 15 (16.5%) a nonpathologic fracture. BCT- and DXA-assessed femoral-neck BMD T scores were strongly correlated (R2 = 0.93). On baseline CT, lower BCT-assessed BMD (odds ratio [OR] 1.80, 95% confidence interval or CI [1.10, 3.25], p = 0.03) was associated with an increased risk of a pathologic fracture. Lower femoral strength (OR 1.63, 95% CI [0.99, 2.71], p = 0.06) was marginally associated with an increased risk of a pathologic fracture. Neither BMD (OR 1.52, 95% CI [0.95, 2.63], p = 0.11) nor strength (OR 1.14, 95% CI [0.75, 1.80], p = 0.57) was associated with a nonpathologic fracture. BCT identified nine (9.9%) men eligible for antiresorptive therapy, of whom four (44%) were not treated. Limitations include low fracture numbers resulting in lower power to detect fracture associations. CONCLUSIONS: Among men diagnosed with mHSPC, BCT assessments were strongly correlated with DXA, predicted subsequent pathologic fracture, and identified additional men indicated for antiresorptive therapy. PATIENT SUMMARY: We assess whether biomechanical computer tomography (BCT) from routine computer tomography (CT) scans can identify fracture risk among patients recently diagnosed with metastatic prostate cancer. We find that BCT and dual-energy x-ray absorptiometry-derived bone mineral density are strongly correlated and that BCT accurately identifies the risk for future fracture. BCT may enable broader fracture risk assessment and facilitate timely interventions to reduce fracture risk in metastatic prostate cancer patients.

3.
Clin Lung Cancer ; 24(5): 474-482, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37076396

RESUMO

OBJECTIVES: We sought to determine the proportion of patients with stage III non-small cell lung cancer (NSCLC) who initiate consolidation durvalumab or other immune checkpoint inhibitors (ICIs) after concurrent chemoradiotherapy (cCRT), as well as reasons for nonreceipt and prognostic implications. MATERIALS AND METHODS: We retrospectively identified consecutive patients with unresectable stage III NSCLC treated with definitive cCRT between October 2017 and December 2021 within a large US academic health system. Patients either received consolidation ICIs (ICI group) or did not (no-ICI group). Baseline characteristics and overall survival (OS) of the groups were assessed. Factors predictive of ICI nonreceipt were evaluated using logistic regression. RESULTS: Of 333 patients who completed cCRT, 229 (69%) initiated consolidation ICIs; 104 (31%) did not. Reasons for ICI nonreceipt included progressive disease post-cCRT (N = 31, 9%), comorbidity or intercurrent illness (N = 25, 8%), cCRT toxicity (N = 23, 7%; 19/23 pneumonitis), and EGFR/ALK alteration (N = 14, 4%). The no-ICI group had worse performance status and a higher rate of baseline pulmonary comorbidity. Larger planning target volume was associated with post-cCRT progressive disease, and higher lung radiation dose with cCRT toxicity. Median OS was 16 months in the no-ICI group and 34.4 months in the ICI group. In the no-ICI group, OS was superior among those with EGFR/ALK alterations (median 44.5 months) and worst among those with progressive disease (median 5.9 months, P < 0.001). CONCLUSION: 31% of patients who completed cCRT for stage III NSCLC did not receive consolidation ICIs. Survival amongst these patients is poor, especially for those with progressive disease post-cCRT.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Estudos Retrospectivos , Estadiamento de Neoplasias , Quimiorradioterapia/efeitos adversos , Receptores ErbB/uso terapêutico , Receptores Proteína Tirosina Quinases
4.
JAMA Netw Open ; 5(4): e227852, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-35438754

RESUMO

Importance: SARS-CoV-2 entry requires the TMPRSS2 cell surface protease. Antiandrogen therapies reduce expression of TMPRSS2. Objective: To determine if temporary androgen suppression induced by degarelix improves clinical outcomes of inpatients hospitalized with COVID-19. Design, Setting, and Participants: The Hormonal Intervention for the Treatment in Veterans With COVID-19 Requiring Hospitalization (HITCH) phase 2, placebo-controlled, double-blind, randomized clinical trial compared efficacy of degarelix plus standard care vs placebo plus standard care on clinical outcomes in men hospitalized with COVID-19 but not requiring invasive mechanical ventilation. Inpatients were enrolled at 14 Department of Veterans Affairs hospitals from July 22, 2020, to April 8, 2021. Data were analyzed from August 9 to October 15, 2021. Interventions: Patients stratified by age, history of hypertension, and disease severity were centrally randomized 2:1 to degarelix, (1-time subcutaneous dose of 240 mg) or a saline placebo. Standard care included but was not limited to supplemental oxygen, antibiotics, vasopressor support, peritoneal dialysis or hemodialysis, intravenous fluids, remdesivir, convalescent plasma, and dexamethasone. Main Outcomes and Measures: The composite primary end point was mortality, ongoing need for hospitalization, or requirement for mechanical ventilation at day 15 after randomization. Secondary end points were time to clinical improvement, inpatient mortality, length of hospitalization, duration of mechanical ventilation, time to achieve a temperature within reference range, maximum severity of COVID-19, and the composite end point at 30 days. Results: The trial was stopped for futility after the planned interim analysis, at which time there were 96 evaluable patients, including 62 patients randomized to the degarelix group and 34 patients in the placebo group, out of 198 initially planned. The median (range) age was 70.5 (48-85) years. Common comorbidities included chronic obstructive pulmonary disorder (15 patients [15.6%]), hypertension (75 patients [78.1%]), cardiovascular disease (27 patients [28.1%]), asthma (12 patients [12.5%]), diabetes (49 patients [51.0%]), and chronic respiratory failure requiring supplemental oxygen at baseline prior to COVID-19 (9 patients [9.4%]). For the primary end point, there was no significant difference between the degarelix and placebo groups (19 patients [30.6%] vs 9 patients [26.5%]; P = .67). Similarly, no differences were observed between degarelix and placebo groups in any secondary end points, including inpatient mortality (11 patients [17.7%] vs 6 patients [17.6%]) or all-cause mortality (11 patients [17.7%] vs 7 patents [20.6%]). There were no differences between degarelix and placebo groups in the overall rates of adverse events (13 patients [21.0%] vs 8 patients [23.5%) and serious adverse events (19 patients [30.6%] vs 13 patients [32.4%]), nor unexpected safety concerns. Conclusions and Relevance: In this randomized clinical trial of androgen suppression vs placebo and usual care for men hospitalized with COVID-19, degarelix did not result in amelioration of COVID-19 severity. Trial Registration: ClinicalTrials.gov Identifier: NCT04397718.


Assuntos
Tratamento Farmacológico da COVID-19 , COVID-19 , Hipertensão , Idoso , Idoso de 80 Anos ou mais , Androgênios , COVID-19/terapia , Hospitalização , Humanos , Imunização Passiva , Masculino , Oxigênio , SARS-CoV-2 , Resultado do Tratamento , Estados Unidos , Soroterapia para COVID-19
6.
Cancer ; 127(18): 3476-3485, 2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34061986

RESUMO

BACKGROUND: Depression is common after a diagnosis of prostate cancer and may contribute to poor outcomes, particularly among African Americans. The authors assessed the incidence and management of depression and its impact on overall mortality among African American and White veterans with localized prostate cancer. METHODS: The authors used the Veterans Health Administration Corporate Data Warehouse to identify 40,412 African American and non-Hispanic White men diagnosed with localized prostate cancer from 2001 to 2013. Patients were followed through 2019. Multivariable logistic regression was used to measure associations between race and incident depression, which were ascertained from administrative and depression screening data. Cox proportional hazards models were used to measure associations between incident depression and all-cause mortality, with race-by-depression interactions used to assess disparities. RESULTS: Overall, 10,013 veterans (24.5%) were diagnosed with depression after a diagnosis of prostate cancer. Incident depression was associated with higher all-cause mortality (adjusted hazard ratio [aHR], 1.27; 95% confidence interval [CI], 1.23-1.32). African American veterans were more likely than White veterans to be diagnosed with depression (29.3% vs 23.2%; adjusted odds ratio [aOR], 1.15; 95% CI, 1.09-1.21). Among those with depression, African Americans were less likely to be prescribed an antidepressant (30.4% vs 31.7%; aOR, 0.85; 95% CI, 0.77-0.93). The hazard of all-cause mortality associated with depression was greater for African American veterans than White veterans (aHR, 1.32 [95% CI, 1.26-1.38] vs 1.15 [95% CI, 1.07-1.24]; race-by-depression interaction P < .001). CONCLUSIONS: Incident depression is common among prostate cancer survivors and is associated with higher mortality, particularly among African American men. Patient-centered strategies to manage incident depression may be critical to reducing disparities in prostate cancer outcomes.


Assuntos
Sobreviventes de Câncer , Depressão , Mortalidade , Neoplasias da Próstata , Negro ou Afro-Americano/psicologia , Negro ou Afro-Americano/estatística & dados numéricos , Sobreviventes de Câncer/psicologia , Sobreviventes de Câncer/estatística & dados numéricos , Depressão/etnologia , Humanos , Incidência , Masculino , Mortalidade/etnologia , Neoplasias da Próstata/etnologia , Neoplasias da Próstata/psicologia , População Branca/psicologia , População Branca/estatística & dados numéricos
7.
JAMA Netw Open ; 4(2): e210070, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-33625512

RESUMO

Importance: Cardiovascular disease is a leading cause of mortality in patients with prostate cancer, and androgen deprivation therapy (ADT) may worsen cardiovascular risk. Adherence to guideline-recommended assessment and management of cardiovascular risk factors (CVRFs) in patients initiating ADT is unknown. Objective: To describe CVRF assessment and management in men with prostate cancer initiating ADT and overall. Design, Setting, and Participants: A cross-sectional analysis of 90 494 men treated within the US Veterans Health Administration diagnosed with prostate cancer between January 1, 2010, and December 31, 2017, was conducted. Participants included men with a history of atherosclerotic cardiovascular disease (ASCVD), and treatment with ADT within 1 year of diagnosis. Data analysis was conducted from September 10, 2019, to July 1, 2020. Main Outcomes and Measures: Rates of comprehensive CVRF assessment, uncontrolled CVRFs, and untreated CVRFs. Comprehensive CVRF assessment was defined as recorded measures for blood pressure, cholesterol, and glucose levels; CVRF control as blood pressure lower than 140/90 mm Hg, low-density lipoprotein cholesterol 130 mg/dL, and hemoglobin A1c less than 7%; and CVRF treatment as receipt of cardiac risk-reducing medications. Multivariable risk difference regression assessed the association between ASCVD and initiation of ADT and these outcomes. Results: Of 90 494 veterans, median age was 66 years (interquartile range, 62-70 years); and 22 700 men (25.1%) received ADT. Overall, 68.1% (95% CI, 67.8%-68.3%) of the men received comprehensive CVRF assessment; 54.1% (95% CI. 53.7%-54.4%) of those assessed had uncontrolled CVRFs, and 29.6% (95% CI, 29.2%-30.0%) of those with uncontrolled CVRFs were not receiving corresponding cardiac risk-reducing medication. Compared with the reference group of patients without ASCVD not receiving ADT, patients with ASCVD not receiving ADT had a 10.4% (95% CI, 9.5%-11.3%) higher probability of comprehensive CVRF assessment, 4.0% (95% CI, 2.9%-5.1%) lower risk of uncontrolled CVRFs, and 22.2% (95% CI, 21.1%-23.3%) lower risk of untreated CVRFs. Similar differences were observed in patients with ASCVD receiving ADT. In contrast, patients without ASCVD receiving ADT had only a 3.0% (95% CI, 2.1%-3.9%) higher probability of comprehensive CVRF assessment, 2.6% (95% CI, 1.6%-3.5%) higher risk of uncontrolled CVRFs, and 5.4% (95% CI, 4.2%-6.6%) lower risk of untreated CVRFs. Conclusions and Relevance: These findings suggest that veterans with prostate cancer had a high rate of underassessed and undertreated CVRFs, and ADT initiation was not associated with substantial improvements in CVRF assessment or management. These findings highlight gaps in care and the need for interventions to improve CVRF mitigation in this population.


Assuntos
Antagonistas de Androgênios/uso terapêutico , Anticolesterolemiantes/uso terapêutico , Anti-Hipertensivos/uso terapêutico , Diabetes Mellitus/tratamento farmacológico , Hipercolesterolemia/tratamento farmacológico , Hipertensão/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Neoplasias da Próstata/tratamento farmacológico , Idoso , Glicemia/metabolismo , Estudos Transversais , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/epidemiologia , Diabetes Mellitus/metabolismo , Hemoglobinas Glicadas/metabolismo , Fatores de Risco de Doenças Cardíacas , Humanos , Hipercolesterolemia/diagnóstico , Hipercolesterolemia/epidemiologia , Hipercolesterolemia/metabolismo , Hipertensão/diagnóstico , Hipertensão/epidemiologia , Masculino , Pessoa de Meia-Idade , Neoplasias da Próstata/epidemiologia , Medição de Risco , Estados Unidos , Veteranos
8.
JAMA Netw Open ; 3(9): e2018318, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32986109

RESUMO

Importance: Conservative management (ie, active surveillance or watchful waiting) is a guideline-based strategy for men with low-risk and intermediate-risk prostate cancer. However, use of conservative management is controversial for African American patients, who have worse prostate cancer outcomes compared with White patients. Objective: To examine the association of African American race with the receipt and duration of conservative management in the Veterans Health Administration (VA), a large equal-access health system. Design, Setting, and Participants: This cohort study used data from the VA Corporate Data Warehouse for 51 543 African American and non-Hispanic White veterans diagnosed with low-risk and intermediate-risk localized node-negative prostate cancer between January 1, 2004, and December 31, 2013. Men who did not receive continuous VA care were excluded. Data were analyzed from February 1 to June 30, 2020. Exposures: All patients received either definitive therapy (ie, prostatectomy, radiation, androgen deprivation therapy) or conservative management (ie, active surveillance or watchful waiting). Main Outcomes and Measures: Receipt of conservative management and (for patients receiving conservative management) time from diagnosis to definitive therapy. Results: The median (interquartile range) age of the 51 543 veterans in our cohort was 65 (61-70) years, and 14 830 veterans (28.8%) were African American individuals. Compared with White veterans, African American veterans were more likely to have intermediate-risk disease (18 988 [51.7%] vs 8526 [57.5%]), 3 or more comorbidities (15 438 [42.1%] vs 7614 [51.3%]), and high disability-related or income-related needs (9078 [24.7%] vs 4614 [31.1%]). Overall, 20 606 veterans (40.0%) received conservative management. African American veterans with low-risk disease (adjusted relative risk, 0.95; 95% CI, 0.92-0.98; P < .001) and intermediate-risk disease (adjusted relative risk, 0.92; 95% CI, 0.87-0.97; P = .002) were less likely to receive conservative management than White veterans. Compared with White veterans, African American veterans with low-risk disease (adjusted hazard ratio, 1.71; 95% CI, 1.50-1.95; P < .001) and intermediate-risk disease (adjusted hazard ratio, 1.46; 95% CI, 1.27-1.69; P < .001) who received conservative management were more likely to receive definitive therapy within 5 years of diagnosis (restricted mean survival time [SE] at 5 years, 1679 [5.3] days vs 1740 [2.4] days; P < .001). Conclusions and Relevance: In this study, conservative management was less commonly used and less durable for African American veterans than for White veterans. Prospective trials should assess the comparative effectiveness of conservative management in African American men with prostate cancer.


Assuntos
Negro ou Afro-Americano/estatística & dados numéricos , Tratamento Conservador/estatística & dados numéricos , Neoplasias da Próstata/etnologia , Veteranos/estatística & dados numéricos , População Branca/estatística & dados numéricos , Idoso , Estudos de Coortes , Humanos , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Neoplasias da Próstata/mortalidade , Fatores de Risco , Estados Unidos , United States Department of Veterans Affairs
9.
Curr Oncol Rep ; 15(4): 396-404, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23674236

RESUMO

Lung cancer will be diagnosed in 230,000 patients in the U.S. in 2013. Adenocarcinoma will be the most common histology, and 10 % of lung cancers will be diagnosed in never or former light smokers. These patients will be those most likely to harbor targetable mutations, in particular, mutations in epidermal growth factor (EGFR). Preclinical work beginning in the 1980s led to the development of EGFR-targeted therapy in lung cancer patients. Analysis of the responders to gefitinib and erlotinib led to the discovery of activating mutations underlying sensitivity to EGFR-directed treatment. Although EGFR-mutant patients have higher response rates, better quality of life, and longer progression free survival, all patients eventually develop resistance. Mutations in the tyrosine kinase domain that render tumors resistant to erlotinib and gefitinib are the most common mechanism of resistance. A second generation of EGFR inhibitors are now making their way to the clinic, with hopes of thwarting these resistance mechanisms or providing more durable responses via irreversible inhibition, as well as targeting of additional HER receptors. Here we review the evolution of EGFR as a target in lung cancer, and the second generation of EGFR inhibitors in development.


Assuntos
Adenocarcinoma/tratamento farmacológico , Antineoplásicos/uso terapêutico , Resistencia a Medicamentos Antineoplásicos , Receptores ErbB/antagonistas & inibidores , Neoplasias Pulmonares/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Humanos , Terapia de Alvo Molecular
10.
Oncologist ; 18(2): 115-22, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23345546

RESUMO

A better understanding of the pathophysiology and evolution of non-small cell lung cancer (NSCLC) has identified a number of molecular targets and spurred development of novel targeted therapeutic agents. The MET receptor tyrosine kinase and its ligand hepatocyte growth factor (HGF) are implicated in tumor cell proliferation, migration, invasion, and angiogenesis in a broad spectrum of human cancers, including NSCLC. Amplification of MET has been reported in approximately 5%-22% of lung tumors with acquired resistance to small-molecule inhibitors of the epidermal growth factor receptor (EGFR). Resistance to EGFR inhibitors is likely mediated through downstream activation of the phosphoinositide 3-kinase /AKT pathway. Simultaneous treatment of resistant tumors with a MET inhibitor plus an EGFR inhibitor can abrogate activation of downstream effectors of cell growth, proliferation, and survival, thereby overcoming acquired resistance to EGFR inhibitors. Development and preclinical testing of multiple agents targeting the HGF-MET pathway, including monoclonal antibodies targeting HGF or the MET receptor and small-molecule inhibitors of the MET tyrosine kinase, have confirmed the crucial role of this pathway in NSCLC. Several agents are now in phase III clinical development for the treatment of NSCLC. This review summarizes the role of MET in the pathophysiology of NSCLC and in acquired resistance to EGFR inhibitors and provides an update on progress in the clinical development of inhibitors of MET for treatment of NSCLC.


Assuntos
Antineoplásicos/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/enzimologia , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/enzimologia , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Proto-Oncogênicas c-met/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-met/metabolismo , Animais , Antineoplásicos/farmacologia , Carcinoma Pulmonar de Células não Pequenas/genética , Humanos , Neoplasias Pulmonares/genética , Terapia de Alvo Molecular , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-met/genética , Transdução de Sinais
11.
J Biomed Mater Res B Appl Biomater ; 70(2): 286-96, 2004 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-15264311

RESUMO

Wound healing is a complex process that often requires treatment with antibiotics. This article reports the initial development of a biodegradable polymeric nanofiber-based antibiotic delivery system. The functions of such a system would be (a) to serve as a biodegradable gauze, and (b) to serve as an antibiotic delivery system. The polymer used in this study was poly(lactide-co-glycolide) (PLAGA), and nanofibers of PLAGA were fabricated with the use of the electrospinning process. The objective of this study was to determine the effect of fabrication parameters: orifice diameter (needle gauge), polymer solution concentration, and voltage per unit length, on the morphology and diameter of electrospun nanofibers. The needle gauges studied were 16 (1.19 mm), 18 (0.84 mm), and 20 (0.58 mm), and the range of polymer solution concentration studied was from 0.10 g/mL to 0.30 g/mL. The effect of voltage was determined by varying the voltage per unit electrospinning distance, and the range studied was from 0.375 kV/cm to 1.5 kV/cm. In addition, the mass per unit area of the electrospun nanofibers as a function of time was determined and the feasibility of antibiotic (cefazolin) loading into the nanofibers was also studied. The results indicate that the diameter of nanofibers decreased with an increase in needle gauge (decrease in orifice diameter), and increased with an increase in the concentration of the polymer solution. The voltage study demonstrated that the average diameter of the nanofibers decreased with an increase in voltage. However, the effect of voltage on fiber diameter was less pronounced as compared to polymer solution concentration. The results of the areal density study indicated that the mass per unit area of the electrospun nanofibers increased linearly with time. Feasibility of drug incorporation into the nanofibers was demonstrated with the use of cefazolin, a broad-spectrum antibiotic. Overall, these studies demonstrated that PLAGA nanofibers can be tailored to desired diameters through modifications in processing parameters, and that antibiotics such as cefazolin can be incorporated into these nanofibers. Therefore, PLAGA nanofibers show potential as antibiotic delivery systems for the treatment of wounds.


Assuntos
Portadores de Fármacos/química , Ácido Láctico/química , Nanoestruturas/química , Ácido Poliglicólico/química , Polímeros/química , Antibacterianos/química , Cefazolina/química , Sistemas de Liberação de Medicamentos , Ácido Láctico/síntese química , Ácido Poliglicólico/síntese química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Polímeros/síntese química , Cicatrização
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