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Multimodal delivery of irinotecan from microparticles with two distinct compartments.

ABSTRACT: In the last several decades, research in the field of drug delivery has been challenged with the fabrication of carrier systems engineered to deliver therapeutics to the target site with sustained and controlled release kinetics. Herein, we report the fabrication of microparticles composed of two distinct compartments: i) one compartment containing a pH responsive polymer, acetal-modified dextran, and PLGA (polylactide-co-glycolide), and ii) one compartment composed entirely of PLGA. We demonstrate the complete release of dextran from the microparticles during a 10-hour period in an acidic pH environment and the complete degradation of one compartment in less than 24h. This is in congruence with the stability of the same microparticles in neutral pH over the 24-hour period. Such microparticles can be used as pH responsive carrier systems for drug delivery applications where their cargo will only be released when the optimum pH window is reached. The feasibility of the microparticle system for such an application was confirmed by encapsulating a cancer therapeutic, irinotecan, in the compartment containing the acetal-modified dextran polymer and the pH dependent release over a 5-day period was studied. It was found that upon pH change to an acidic environment, over 50% of the drug was first released at a rapid rate for 10h, similar to that observed for the dextran release, before continuing at a more controlled rate for 4 days. As such, these microparticles can play an important role in the fabrication of novel drug delivery systems due to the selective, controlled, and pH responsive release of their encapsulated therapeutics.

SUBMITTER: Rahmani S

PROVIDER: S-EPMC5550899 | biostudies-literature | 2013 Nov

REPOSITORIES: biostudies-literature

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Multimodal delivery of irinotecan from microparticles with two distinct compartments.

Rahmani Sahar S Park Tae-Hong TH Dishman Acacia Frances AF Lahann Joerg J

Journal of controlled release : official journal of the Controlled Release Society 20130823 1

In the last several decades, research in the field of drug delivery has been challenged with the fabrication of carrier systems engineered to deliver therapeutics to the target site with sustained and controlled release kinetics. Herein, we report the fabrication of microparticles composed of two distinct compartments: i) one compartment containing a pH responsive polymer, acetal-modified dextran, and PLGA (polylactide-co-glycolide), and ii) one compartment composed entirely of PLGA. We demonstr ...[more]

PMID: 23973814

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Project description:BackgroundBoth protracted irinotecan and antiangiogenesis therapy have shown promising efficacy against Ewing sarcoma (EWS).MethodsPatients diagnosed with recurrent or refractory EWS were enrolled and further categorized into cohort A (≥16 years) or cohort B (<16 years). In the dose-defining phase Ib portion, anlotinib was given daily at a fixed dose, while a 3+3 design with dose de-escalation was used to determine the dose of irinotecan. The next dose-expanding phase II portion employed a conventional two-stage study design model. The primary endpoint was objective response rate at 12 weeks (ORR12w ).ResultsA total of 41 patients finally received the treatment regimen, including 29 in cohort A and 12 in cohort B. For cohort A, the first five patients were treated at the initial level of 20 mg/m2 /d d × 5 × 2, and two of them subsequently a dose-limiting toxicity (DLT). An additional six patients were then treated at 15 mg/m2 without any DLT, and the RP2D was determined. Notably, 23 out of 24 patients in cohort A were available for response evaluation at 12 weeks. ORR12w was determined to be 62.5%. For cohort B, no DLT was observed in the first six patients at the initial dose level. At last, 12 patients were included in cohort B. The ORR12w was 83.3%. The most frequently observed grade 3/4 adverse events were leukopenia (28.5%), neutropenia (24.4%), anemia (8.7%), and diarrhea (3.7%).ConclusionThe combination of vincristine, irinotecan, and anlotinib demonstrated an acceptable toxicity profile and promising clinical efficacy in patients with advanced EWS.Implications for practiceThis is the first trial to evaluate an irinotecan-based regimen in combination with antiangiogenesis tyrosine kinase inhibitors in Ewing sarcoma (EWS). A 3+3 design with dose de-escalation was used to determine the most appropriate dose of irinotecan in each cohort. The next dose-expanding phase II portion employed a conventional two-stage study design model. The objective response rate was 62.5% for adults and 83.3% for children. Median overall survival was not matured. This study shows that the combination of vincristine, irinotecan, and anlotinib demonstrates an acceptable toxicity profile and promising clinical efficacy in patients with advanced EWS.

Project description:ObjectivesDifferentiation between high-grade glioma (HGG) and post-treatment-related effects (PTRE) is challenging, but advanced imaging techniques were shown to provide benefit. We aim to investigate microstructure characteristics of metabolic compartments identified from amino acid PET and to evaluate the diagnostic potential of this multimodal and integrative O-(2-18F-fluoroethyl)-L-tyrosine-(FET)-PET and fast diffusion kurtosis imaging (DKI) approach for the detection of recurrence and IDH genotyping.MethodsFifty-nine participants with neuropathologically confirmed recurrent HGG (n = 39) or PTRE (n = 20) were investigated using static 18F-FET PET and a fast-DKI variant. PET and advanced diffusion metrics of metabolically defined (80-100% and 60-75% areas of 18F-FET uptake) compartments were assessed. Comparative analysis was performed using Mann-Whitney U tests with Holm-Šídák multiple-comparison test and Wilcoxon signed-rank test. Receiver operating characteristic (ROC) curves, regression, and Spearman's correlation analysis were used for statistical evaluations.ResultsCompared to PTRE, recurrent HGG presented increased 18F-FET uptake and diffusivity (MD60), but lower (relative) mean kurtosis tensor (rMKT60) and fractional anisotropy (FA60) (respectively p < .05). Diffusion metrics determined from the metabolic periphery showed improved diagnostic performance - most pronounced for FA60 (AUC = 0.86, p < .001), which presented similar benefit to 18F-FET PET (AUC = 0.86, p < .001) and was negatively correlated with amino acid uptake (rs = - 0.46, p < .001). When PET and DKI metrics were evaluated in a multimodal biparametric approach, TBRmax + FA60 showed highest diagnostic accuracy (AUC = 0.93, p < .001), which improved the detection of relapse compared to PET alone (difference in AUC = 0.069, p = .04). FA60 and MD60 distinguished the IDH genotype in the post-treatment setting.ConclusionDetection of glioma recurrence benefits from a multimodal and integrative PET/DKI approach, which presented significant diagnostic advantage to the assessment based on PET alone.Clinical relevance statementA multimodal and integrative 18F-FET PET/fast-DKI approach for the non-invasive microstructural characterization of metabolic compartments provided improved diagnostic capability for differentiation between recurrent glioma and post-treatment-related changes, suggesting a role for the diagnostic workup of patients in post-treatment settings.Key points• Multimodal PET/MRI with integrative analysis of 18F-FET PET and fast-DKI presents clinical benefit for the assessment of CNS cancer, particularly for the detection of recurrent high-grade glioma. • Microstructure markers of the metabolic periphery yielded biologically pertinent estimates characterising the tumour microenvironment, and, thereby, presented improved diagnostic accuracy with similar accuracy to amino acid PET. • Combined 18F-FET PET/fast-DKI achieved the best diagnostic performance for detection of high-grade glioma relapse with significant benefit to the assessment based on PET alone.

Dataset Information

Multimodal delivery of irinotecan from microparticles with two distinct compartments.

Publications

Multimodal delivery of irinotecan from microparticles with two distinct compartments.

Similar Datasets

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