Localized synergistic co-delivery to glioblastoma by in-situ GelMA containing ibrutinib-PLGA-PEG-folate nanoparticle and octreotide microsphere

Glioblastoma (GBM), a grade IV astrocytoma, is defined by its rapid proliferation, strong infiltrative nature, resistance to chemotherapy, and tendency to recur quickly, even after surgery and standard treatments. We hypothesize that the localized delivery of ibrutinib loaded in PLGA-PEG-folate nanoparticles (IBT-PPF-NPs) and Octreotide PLGA microparticles (OCT-PLGA-MPs) loaded GelMA hydrogel into GBM tumors represents a promising approach, as it can achieve a high local drug concentration in the tumor site and increase the efficacy of treatment. The OCT-PLGA-MPs were prepared and incorporated with IBT-PPF-NPs in GelMA-alginate hydrogel. The in-situ hydrogel was developed using GelMA combined with different alginate concentrations, and its swelling behavior, degradation rate, and mechanical and morphological characteristics were investigated. The efficiency of Octreotide entrapment in PLGA microparticle was 55.0% ± 0.7 with 5.0% ± 0.03 drug loading. The particle size of the OCT-PLGA-MPs was 103 µm ± 5.6. Octreotide exhibited a gradual release profile from the microparticles (MPs), with approximately 5.2% released within the first 24 hours and up to 71% released over 84 days. The embedding of OCT-PLGA-MPs within the hydrogel and IBT-PPF-NPs effectively controls the initial burst release typically observed with NPs and MPs. The structure of the GelMA was verified through H NMR analysis. The selected hydrogel demonstrated an elastic modulus of 18.45 kPa, consistent with the mechanical properties of brain tissue. MTT assay results revealed that IBT-PPF-NPs inhibit the growth of glioma cells in a dose-dependent manner, while Octreotide alone exhibited no cytotoxic effect on glioma cells. The MTT results also indicate an additive effect between the combination of the two treatments. An in vivo study was performed to evaluate the effectiveness of intratumoral injection of hydrogel in inhibiting tumor growth by MRI imaging. Then the collected brain tumors were evaluated by H&E and IHC staining analysis. The hydrogel containing IBT-PPF-NPs and OCT-PLGA-MPs effectively suppressed tumor growth in the in vivo study. The IHC results revealed a significant increase in caspase-3 levels and a decrease in the Ki-67 marker in glioma tumor cells by ibrutinib. On the other hand, Octreotide notably reduced CD31 expression, inhibiting angiogenesis and effectively suppressing both tumor growth and glioma cell proliferation in the in vivo study. It holds potential as a valuable approach for post-resection management of GBM, preceding standard chemo-radiation therapy.