Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
1.
J Med Econ ; 26(1): 1108-1121, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37632452

RESUMO

OBJECTIVE: Nivolumab plus ipilimumab (NIVO + IPI) and pembrolizumab plus axitinib (PEM + AXI) have demonstrated significant clinical benefits as first-line (1 L) treatments for intermediate/poor-risk advanced renal cell carcinoma (aRCC) patients. This study aimed to assess the cost-effectiveness of NIVO + IPI versus PEM + AXI from a Brazilian private healthcare system perspective, utilizing a novel approach to estimate comparative efficacy between the treatments. METHODS: A three-state partitioned survival model (progression-free, progressed, and death) was developed to estimate costs, life-years (LYs), quality-adjusted LYs (QALYs), and the incremental cost-utility ratio (ICUR) over a 40-year time horizon. In the absence of head-to-head comparisons between NIVO + IPI and PEM + AXI, clinical data for NIVO + IPI was obtained from CheckMate 214 (NCT02231749) and for PEM + AXI from KEYNOTE-426 (NCT02853331). A matching-adjusted indirect comparison was conducted to account for the imbalance of treatment effect modifiers between the trials. Patient characteristics, resource use, health state utilities, and costs were based on Brazilian-specific sources. Costs and health outcomes were both discounted by 5% annually in line with Brazilian guidelines. The robustness of the results was evaluated through extensive sensitivity analysis and scenario analyses. RESULTS: When comparing the matched versus unmatched OS, PFS, and TTD curves there was no noteworthy difference. NIVO + IPI was associated with cost savings (R$ 350,232), higher LYs (5.54 vs. 4.61), and QALYs (4.74 vs. 3.76) versus PEM + AXI, resulting in NIVO + IPI dominating PEM + AXI. Key model drivers were the treatment duration for PEM, NIVO, and AXI. NIVO + IPI remained dominant in all scenario analyses, which indicated that model results were robust to alternative modelling inputs or assumptions. CONCLUSIONS: This analysis shows that NIVO + IPI is estimated to be a life-extending and potentially cost-saving 1 L treatment option when compared with PEM + AXI for intermediate/poor-risk a RCC patients in the Brazilian private healthcare system.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Humanos , Nivolumabe/uso terapêutico , Ipilimumab/uso terapêutico , Carcinoma de Células Renais/tratamento farmacológico , Carcinoma de Células Renais/patologia , Axitinibe/uso terapêutico , Prognóstico , Análise Custo-Benefício , Brasil , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Atenção à Saúde , Neoplasias Renais/tratamento farmacológico , Neoplasias Renais/patologia
2.
J Comp Eff Res ; 12(8): e230004, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37431849

RESUMO

Aim: Network meta-analyses (NMAs) increasingly feature time-varying hazards to account for non-proportional hazards between different drug classes. This paper outlines an algorithm for selecting clinically plausible fractional polynomial NMA models. Methods: The NMA of four immune checkpoint inhibitors (ICIs) + tyrosine kinase inhibitors (TKIs) and one TKI therapy for renal cell carcinoma (RCC) served as case study. Overall survival (OS) and progression free survival (PFS) data were reconstructed from the literature, 46 models were fitted. The algorithm entailed a-priori face validity criteria for survival and hazards, based on clinical expert input, and predictive accuracy against trial data. Selected models were compared with statistically best-fitting models. Results: Three valid PFS and two OS models were identified. All models overestimated PFS, the OS model featured crossing ICI + TKI versus TKI curves as per expert opinion. Conventionally selected models showed implausible survival. Conclusion: The selection algorithm considering face validity, predictive accuracy, and expert opinion improved the clinical plausibility of first-line RCC survival models.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Humanos , Carcinoma de Células Renais/tratamento farmacológico , Inibidores de Checkpoint Imunológico/uso terapêutico , Metanálise em Rede , Inibidores de Proteínas Quinases/uso terapêutico , Neoplasias Renais/tratamento farmacológico
3.
Pharmacoecon Open ; 7(2): 273-284, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36897427

RESUMO

OBJECTIVE: To evaluate the economic value of nivolumab versus docetaxel for advanced non-small cell lung cancer (aNSCLC) treatment after platinum-based chemotherapy in adults without epidermal growth factor receptor/anaplastic lymphoma kinase aberrations in China. METHODS: Partitioned survival models evaluated lifetime costs and benefits of nivolumab versus docetaxel by squamous and non-squamous histologies from a Chinese healthcare payer perspective. Progression-free disease, progressed disease, and death health states were considered over a 20-year time horizon. Clinical data were derived from the CheckMate pivotal Phase III trials (ClinicalTrials.gov identifiers: NCT01642004, NCT01673867, NCT02613507); patient-level survival data were extrapolated using parametric functions. China-specific health state utilities, healthcare resource utilisation, and unit costs were applied. Sensitivity analyses explored uncertainty. RESULTS: Nivolumab resulted in extended survival (1.489 and 1.228 life-years [1.226 and 0.995 discounted]) and quality-adjusted survival benefits (1.034 and 0.833 quality-adjusted life-years) at additional costs of ¥214,353 (US$31,829) and ¥158,993 (US$23,608) versus docetaxel in squamous and non-squamous aNSCLC, respectively. Nivolumab was associated with higher acquisition costs, lower subsequent treatment costs, and lower adverse event management costs than docetaxel in both histologies. Drug acquisition costs, discount rate for outcomes, and average body weight were key model drivers. Stochastic results aligned with the deterministic results. CONCLUSIONS: Nivolumab yielded survival and quality-adjusted survival benefits at incremental cost versus docetaxel in aNSCLC. As a traditional healthcare payer perspective was applied, the true economic benefit of nivolumab may be underestimated as not all treatment benefits and costs of relevance to society were considered.

4.
Pharmacoecon Open ; 7(4): 567-577, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36757568

RESUMO

OBJECTIVE: This study assessed the cost-effectiveness of nivolumab plus ipilimumab versus both sunitinib and pazopanib for the treatment of first-line unresectable advanced renal cell carcinoma (aRCC) from a healthcare system perspective in Switzerland. METHODS: A three-state partitioned survival model, consisting of progression-free, progressed disease, and death, was constructed. Efficacy estimates were based on data from the CheckMate 214 trial (NCT02231749) with a minimum follow-up of 42 months. Two Swiss oncologists were consulted to determine disease management resource use. Costs were derived from the Swiss tariff lists for outpatient (TARMED Online Browser 1.09) and inpatient (2020 data from Swiss diagnosis-related groups) treatments. Drug acquisition costs (ex-factory prices) were obtained from the March 2020 price list published by the Swiss Federal Office of Public Health. Treatment-specific EQ-5D-3L-based utilities were derived from CheckMate 214 using a French value set as a proxy for Switzerland. The model utilized a 1-week cycle length and a 40-year time horizon, with costs and effects discounted by 3.0% per annum. One-way sensitivity analyses, probabilistic analysis, and scenario analyses assessed the robustness of the results. RESULTS: Nivolumab plus ipilimumab yielded incremental 1.43 life-years and 1.36 lifetime discounted quality-adjusted life-years (QALYs) relative to sunitinib and pazopanib at an additional cost of 147,453 Swiss Francs (CHF) and CHF145,643, respectively. With an incremental cost-utility ratio of CHF108,326 per QALY gained versus sunitinib, and CHF106,996 per QALY gained versus pazopanib, the nivolumab plus ipilimumab combination can be considered a cost-effective option for the treatment of patients with aRCC in Switzerland, with a willingness-to-pay threshold of CHF200,000. Sensitivity and scenario analyses confirmed the robustness of the deterministic results. CONCLUSIONS: This study showed that nivolumab plus ipilimumab, which represents one of the standard-of-care first-line treatments for intermediate- or poor-risk aRCC patients, is a life-extending and cost-effective treatment option for patients in Switzerland.

5.
Eur Urol Oncol ; 6(3): 339-348, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36842942

RESUMO

BACKGROUND: The comparative efficacy and health-related quality of life (HRQoL) outcomes of nivolumab plus cabozantinib versus pembrolizumab plus axitinib as first-line treatments for advanced renal cell carcinoma (aRCC) have not been assessed in head-to-head trials. OBJECTIVE: To assess the efficacy and HRQoL outcomes of nivolumab plus cabozantinib versus pembrolizumab plus axitinib. DESIGN, SETTING, AND PARTICIPANTS: Patient-level data for nivolumab plus cabozantinib from the CheckMate 9ER trial and published data for pembrolizumab plus axitinib from the KEYNOTE-426 trial were used. CheckMate 9ER data were reweighted to match the key baseline characteristics as reported in KEYNOTE-426. INTERVENTION: Nivolumab (240 mg every 2 wk) plus cabozantinib (40 mg once daily) and pembrolizumab (200 mg every 3 wk) plus axitinib (5 mg twice daily, initially). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Hazard ratios (HRs) for progression-free survival (PFS), duration of response, overall survival (OS), and deterioration in HRQoL were assessed using weighted Cox proportional-hazard models, with sunitinib as a common anchor. Objective response rates (ORRs) and changes in HRQoL scores from baseline were assessed as difference-in-differences for the two treatments relative to sunitinib. RESULTS AND LIMITATIONS: After balancing patient characteristics between the trials, nivolumab plus cabozantinib was associated with significantly improved PFS (HR [95% confidence interval {CI}] 0.70 [0.53-0.93]; p = 0.01) and a significantly decreased risk of confirmed deterioration in HRQoL (Functional Assessment of Cancer Therapy-Kidney Symptom Index-Disease-related Symptoms: HR [95% CI] 0.48 [0.34-0.69]) versus pembrolizumab plus axitinib. OS was similar between treatments (HR [95% CI] 0.99 [0.67-1.44]; p = 0.94). Nivolumab plus cabozantinib was associated with numerically greater ORRs (difference-in-difference [95% CI] 8.4% [-1.7 to 18.4]; p = 0.10) and longer duration of response (HR [95% CI] 0.79 [0.47-1.31]; p = 0.36) than pembrolizumab plus axitinib. Comparative studies using data with a longer duration of follow-up are warranted. CONCLUSIONS: Nivolumab plus cabozantinib significantly improved PFS and HRQoL compared with pembrolizumab plus axitinib as first-line treatment for aRCC. PATIENT SUMMARY: This study was conducted to indirectly compare the results of two immunotherapy-based combinations-nivolumab plus cabozantinib versus pembrolizumab plus axitinib-for patients who have not received any treatment for advanced renal cell carcinoma. Patients who received nivolumab plus cabozantinib had a significant improvement in the length of time without worsening of their disease and in their perceived physical and mental health compared with pembrolizumab plus axitinib; patients remained alive for a similar length of time from the start of either treatment. This analysis further adds to our current knowledge of the relative benefits of these two treatment regimens and will help with physician and patient treatment decisions.


Assuntos
Antineoplásicos , Carcinoma de Células Renais , Neoplasias Renais , Humanos , Carcinoma de Células Renais/patologia , Nivolumabe/uso terapêutico , Axitinibe/uso terapêutico , Axitinibe/efeitos adversos , Sunitinibe/efeitos adversos , Antineoplásicos/uso terapêutico , Neoplasias Renais/patologia , Qualidade de Vida
6.
Value Health ; 26(4): 465-476, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36503035

RESUMO

OBJECTIVES: Network meta-analysis (NMA) of time-to-event outcomes based on constant hazard ratios can result in biased findings when the proportional hazards (PHs) assumption does not hold in a subset of trials. We aimed to summarize the published non-PH NMA methods for time-to-event outcomes, demonstrate their application, and compare their results. METHODS: The following non-PH NMA methods were compared through an illustrative case study in oncology of 4 randomized controlled trials in terms of progression-free survival and overall survival: (1) 1-step or (2) 2-step multivariate NMAs based on traditional survival distributions or fractional polynomials, (3) NMAs with restricted cubic splines for baseline hazard, and (4) restricted mean survival NMA. RESULTS: For progression-free survival, the PH assumption did not hold across trials and non-PH NMA methods better reflected the relative treatment effects over time. The most flexible models (fractional polynomials and restricted cubic splines) fit better to the data than the other approaches. Estimated hazard ratios obtained with different non-PH NMA methods were similar at 5 years of follow-up but differed thereafter in the extrapolations. Although there was no strong evidence of PH violation for overall survival, non-PH NMA methods captured this uncertainty in the relative treatment effects over time. CONCLUSIONS: When the PH assumption is questionable in a subset of the randomized controlled trials, we recommend assessing alternative non-PH NMA methods to estimate relative treatment effects for time-to-event outcomes. We propose a transparent and explicit stepwise model selection process considering model fit, external constraints, and clinical validity. Given inherent uncertainty, sensitivity analyses are suggested.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Humanos , Carcinoma de Células Renais/terapia , Metanálise em Rede , Neoplasias Renais/terapia , Modelos de Riscos Proporcionais
7.
Artigo em Inglês | LILACS, ECOS | ID: biblio-1353168

RESUMO

Objective: To perform an analysis over time of the number needed to treat (NNT) and the cost of preventing an event (COPE) for nivolumab + ipilimumab (NIVO+IPI) and pembrolizumab + axitinib (PEMBRO+AXI) as first-line treatments for advanced renal cell carcinoma patients with intermediate or poor-risk, under the Brazilian private healthcare system perspective. Methods: The NNT for overall survival (OS) and progression-free survival (PFS) from 12-month to maximum available follow-up from CheckMate 214 and KEYNOTE-426 studies were used to estimate the COPE. Treatment costs were estimated considering the labeled dosing and median PFS as a proxy for treatment duration. Results: The OS NNT for NIVO+IPI decreased from 12 to 8 and for PEMBRO+AXI increased slightly from 7 to 8 at 12 and 42 months, respectively. For PFS, NNT for NIVO+IPI decreased from 15 to 6, and for PEMBRO+AXI increased from 7 to 10 at 12 and 30 months. The estimated treatment cost is R$ 638,620 for an estimated median of 11.2 months of NIVO+IPI treatment and R$ 966,818 for 13.8 months of PEMBRO+AXI treatment. COPE for OS at 12 and 42 months was R$ 7,663,440 and R$ 5,108,960 with NIVO+IPI and R$ 6,047,417 and R$ 7,734,547 with PEMBRO+AXI. For PFS, COPE at 12 and 30 months was R$ 9,579,300 and R$ 3,831,720 with NIVO+IPI and R$ 6,047,417 and R$ 9,668,184 with PEMBRO+AXI. Conclusions: Treatment with NIVO+IPI results in lower COPE than PEMBRO+AXI from month 18 onwards, driven by lower treatment costs and improved NNT over time with NIVO+IPI


Objetivo: Analisar ao longo do tempo o número necessário a tratar (NNT) e o custo para prevenir um evento (COPE) para nivolumabe + ipilimumabe (NIVO+IPI) e pembrolizumabe + axitinibe (PEMBRO+AXI) na primeira linha de tratamento do carcinoma de células renais avançado com risco intermediário ou alto na perspectiva do sistema suplementar de saúde brasileiro. Métodos: O NNT para sobrevida global (SG) e sobrevida livre de progressão (SLP) para 12 meses até o máximo de tempo de seguimento disponível dos estudos CheckMate 214 e KEYNOTE-426 foi usado para estimar o COPE. Custos de tratamento foram estimados considerando a dosagem em bula e a mediana de SLP como aproximação para duração de tratamento. Resultados: O NNT de SG para NIVO+IPI reduziu de 12 para 8 e para PEMBRO+AXI subiu de 7 para 8 em 12 e 42 meses, respectivamente. Para SLP, NIVO+IPI teve redução de 15 para 6 e para PEMBRO+AXI aumentou de 7 para 10 em 12 e 30 meses. O custo estimado é de R$ 638.620 para mediana de 11,2 meses de tratamento com NIVO+IPI e de R$ 966.818 para 13,8 meses com PEMBRO+AXI. O COPE para SG foi de R$ 7.663.440 e R$ 5.108.960 com NIVO+IPI e de R$ 6.047.417 e R$ 7.734.547 com PEMBRO+AXI para 12 e 42 meses. Para SLP, foi de R$ 9.579.300 e R$ 3.831.720 com NIVO+IPI e de R$ 6.047.417 e R$ 9.668.184 com PEMBRO+AXI em 12 e 30 meses. Conclusões: O tratamento com NIVO+IPI resulta em menor COPE, em comparação com PEMBRO+AXI, a partir de 18 meses de seguimento, justificado por menor custo de tratamento e melhora do NNT ao longo do tempo com NIVO+IPI


Assuntos
Carcinoma de Células Renais , Custos de Cuidados de Saúde , Custos e Análise de Custo , Nivolumabe , Axitinibe
8.
Curr Med Res Opin ; 34(12): 2143-2150, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30032697

RESUMO

OBJECTIVES: The combination of a cyclin-dependent kinase 4 and 6 (CDK 4/6) inhibitor with the aromatase inhibitor letrozole is a safe and effective alternative to letrozole monotherapy for first-line hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) breast cancer. This study evaluates the budget impact of using the CDK 4/6 inhibitor ribociclib plus letrozole as a first-line treatment option for postmenopausal women with HR+/HER2- advanced breast cancer, from a United States (US) payer perspective. METHODS: A cohort-based budget impact model was used to calculate the incremental cost of introducing ribociclib plus letrozole over three years for the target population. The analysis compared two scenarios: treatment options excluding or including ribociclib plus letrozole. Market shares were derived from market research and the assumption was the introduction of ribociclib plus letrozole would only displace existing CDK-based therapies. Treatment duration was based on the median time to treatment discontinuation or median progression-free survival for first-line treatment, and on clinical trial data for second- and third-line treatment. Acquisition costs were based on wholesale acquisition costs and considered co-payment. Costs for drug administration and monitoring, subsequent therapy, and relevant adverse events were included. RESULTS: Of 1 million insured members, 263 were eligible for CDK 4/6 inhibitor treatment. Cumulative total savings with ribociclib plus letrozole were $3.01M over three years, corresponding to a cumulative incremental cost saving of $318.11 per member treated per month. CONCLUSIONS: In the US, ribociclib plus letrozole represents a cost-saving first-line treatment option for postmenopausal women with HR+/HER2- advanced breast cancer.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Pós-Menopausa , Aminopiridinas/administração & dosagem , Orçamentos , Feminino , Humanos , Letrozol/administração & dosagem , Purinas/administração & dosagem , Receptor ErbB-2/metabolismo , Receptores de Estrogênio/metabolismo , Estados Unidos
9.
J Manag Care Spec Pharm ; 24(6): 514-523, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29799329

RESUMO

BACKGROUND: U.S. regulatory approvals of the cyclin-dependent kinase 4 and 6 (CDK 4/6) inhibitors ribociclib and palbociclib as add-ons to letrozole greatly enhance the prospects for treating postmenopausal women with hormone receptor-positive (HR+)/human epidermal receptor 2-negative (HER2-) advanced or metastatic breast cancer. Clinical trials have established that the combination of a CDK 4/6 inhibitor with letrozole can significantly improve progression-free survival (PFS) versus letrozole monotherapy and is safe and well tolerated. Cost-effectiveness studies are required to inform payers and clinical decision makers on the money value of combination treatment in clinical practice. OBJECTIVE: To evaluate the cost-effectiveness of ribociclib plus letrozole versus palbociclib plus letrozole and versus letrozole monotherapy in the first-line treatment of postmenopausal women with HR+/HER2- advanced or metastatic breast cancer from a U.S. private third-party payer perspective. METHODS: A partitioned survival model including 3 health states (progression free, with either overall response or stable disease; progressed disease; and death) simulated lifetime costs and outcomes over a 40-year lifetime horizon with a 1-month cycle length. Clinical efficacy data (PFS and overall survival [OS]) were derived from a phase III trial of ribociclib plus letrozole (MONALEESA-2; NCT01958021), a phase II trial of palbociclib plus letrozole (PALOMA-1; NCT00721409), and a Bayesian network meta-analysis. Health care costs included drug acquisition and monitoring, disease management, subsequent therapies, and serious drug-related adverse events. Effectiveness was measured in life-years, derived from survival projections, and in quality-adjusted life-years (QALYs), calculated from time spent in each state combined with health-state utility values. A one-way deterministic sensitivity analysis explored the impact of uncertainty in key model parameters on results, and probabilistic uncertainty was assessed through a Monte Carlo probabilistic sensitivity analysis. RESULTS: Ribociclib plus letrozole was dominant versus palbociclib plus letrozole, with a cost saving of $43,037 and a gain of 0.086 QALYs. Compared with letrozole monotherapy, ribociclib plus letrozole was associated with an incremental cost of $144,915 and an incremental QALY of 0.689, equating to an incremental cost-effectiveness ratio of $210,369 per QALY. Key model drivers included OS HRs for palbociclib plus letrozole versus letrozole and for ribociclib plus letrozole versus letrozole, the PFS HR for palbociclib plus letrozole versus letrozole, PD health-state costs, utility of response, and cost discount rate. The probabilities that ribociclib plus letrozole was cost-effective versus letrozole at thresholds of $50,000, $100,000 and $200,000 per QALY gained were 1.6%, 6.3%, and 50.5%, respectively. CONCLUSIONS: In the United States, ribociclib plus letrozole is a cost-effective alternative to palbociclib plus letrozole for the first-line treatment of postmenopausal women with HR+/HER2- advanced or metastatic breast cancer. Ribociclib plus letrozole is also cost-effective versus letrozole monotherapy at willingness-to-pay thresholds greater than $198,000 per QALY (for probabilistic analysis). DISCLOSURES: Funding for this study was provided by Novartis, which manufactures ribociclib and provided input on the study design and data collection, analysis, and interpretation. Mistry, May, Suri, and Young are employees of PAREXEL. Tang, Mishra, D. Bhattacharyya, and Dalal are employees of Novartis. S. Bhattacharyya was an employee of Novartis during the study period. Tang and Dalal hold stock in Novartis. Brixner, Oderda, and Biskupiak were paid by Millcreek Outcomes Group as consultants for work on this project. Brixner has also consulted for AstraZeneca, UCB, Regeneron, and Abbott.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/economia , Neoplasias da Mama/tratamento farmacológico , Análise Custo-Benefício , Inibidores de Proteínas Quinases/economia , Aminopiridinas/economia , Aminopiridinas/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/economia , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Intervalo Livre de Doença , Feminino , Humanos , Letrozol , Modelos Biológicos , Modelos Econômicos , Nitrilas/economia , Nitrilas/uso terapêutico , Piperazinas/economia , Piperazinas/uso terapêutico , Pós-Menopausa , Inibidores de Proteínas Quinases/uso terapêutico , Purinas/economia , Purinas/uso terapêutico , Piridinas/economia , Piridinas/uso terapêutico , Receptor ErbB-2/metabolismo , Receptores de Estrogênio/metabolismo , Receptores de Progesterona/metabolismo , Análise de Sobrevida , Resultado do Tratamento , Triazóis/economia , Triazóis/uso terapêutico , Estados Unidos/epidemiologia
10.
Adv Healthc Mater ; 1(3): 308-15, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-23184745

RESUMO

Poly(γ-glutamic acid) (γ-PGA) is a biocompatible, enzymatically-degradable, natural polymer with a higher resistance to hydrolysis than polyesters commonly used for tissue engineering scaffolds such as poly(L-lactide) (PLLA). Notably, γ-PGA's free carboxyl side groups allow for simple chemical functionalization, making it a versatile candidate for producing scaffolds. Here, a series of water-resistant fibrous scaffolds were engineered from ethyl (Et), propyl (Pr) and benzyl (Bn) esterifications of γ-PGA. All scaffolds were non-cytotoxic and γ-PGA-Bn showed an increase in cell adhesion of hMSCs compared to γ-PGA-Et and γ-PGA-Pr. Moreover, cells on γ-PGA-Bn showed three-fold higher viability at day 14 and significantly higher adhesion when compared with PLLA scaffolds, despite having a similar hydrophobicity. Cell attachment decreased by 40% when the polymer was only partially modified with benzyl groups (γ-PGA-Bn-77%), but was restored when integrin-binding RGD peptide was conjugated to the remaining free carboxylic groups, indicating the peptide was accessible and able to bind integrins. The mechanism behind the cell-material interactions on γ-PGA-Bn scaffolds was further investigated through protein adsorption and fibronectin conformation experiments. These results, in addition to the cell-adhesion studies, suggest an inherent effect of the benzyl modification in the mechanism of cell attachment to γ-PGA-Bn scaffolds. Finally, γ-PGA-Bn scaffolds cultured in osteogenic media were also efficient in supporting hMSCs differentiation towards an osteogenic lineage as determined by alkaline phosphatase and Runx2 gene expression. Taken together these data suggest that esterified γ-PGA polymer scaffolds are new and versatile candidates for tissue engineering applications and that, intriguingly, aromatic functionality plays a key role in the cell-scaffold interaction.


Assuntos
Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/fisiologia , Osteoblastos/citologia , Osteoblastos/fisiologia , Ácido Poliglutâmico/análogos & derivados , Engenharia Tecidual/instrumentação , Alicerces Teciduais , Diferenciação Celular , Proliferação de Células , Sobrevivência Celular , Células Cultivadas , Materiais Revestidos Biocompatíveis/química , Desenho de Equipamento , Análise de Falha de Equipamento , Humanos , Teste de Materiais , Osteogênese/fisiologia , Ácido Poliglutâmico/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...