ID #1088 Nanoparticles with iRGD-DSPE-PEG for CNS drug delivery and anti-glioma therapy
Qiang Fu, Jiatong Dai, Jiajie Chen, Jianan Li, Jingyi Huang, Xiaoyu Lin, Shiyao Song, Hao Xiong, Yanlai TangAbstract
Objective
This study aimed to construct an arsenic trioxide (ATO)-loaded nanodrug delivery system, termed iRGD-PEG-ATO, using DSPE as the carrier modified with polyethylene glycol (PEG) and conjugated with the tumor-targeting peptide iRGD. The system was designed to overcome the limitations of free ATO, including poor blood-brain barrier (BBB) penetration, rapid systemic clearance, narrow therapeutic window, and lack of tumor-specific distribution, thereby providing a novel strategy for glioma therapy.
Methods
The targeted nanocarrier iRGD-PEG-ATO was synthesized based on iRGD-DSPE-PEG and the αvβ3 integrin-targeting ligand. The nanoparticles were characterized using XPS, TEM,FTIR. In vitro drug release was evaluated via the dialysis bag method. Cytotoxicity and antitumor efficacy were assessed using MTT and live/dead assays. Flow cytometry was employed to analyze effects on cell apoptosis and cell cycle. An in vitro BBB model co-cultured with U87 glioma cells was established to study the tumor-suppressive effects of different ATO formulations after crossing the BBB. An orthotopic U87-LUC glioma model in nude mice was constructed to evaluate the tumor inhibition and survival benefits of iRGD-PEG-ATO. Ki67 and TUNEL immunohistochemistry were performed to assess its effects on tumor cell proliferation and apoptosis in vivo. Transcriptome sequencing was conducted on cells treated with the nanomaterial. Western blot and IHC were used to examine TGFBR2 protein expression in glioma cells and to investigate the impact on the MAPK pathway following treatment with iRGD-PEG-ATO alone or in combination with temozolomide.
Results
In vitro release studies showed that iRGD-PEG-ATO released more ATO at pH 5.6 (42.7% within 24 hours) compared to pH 7.4. In the in vitro BBB model, iRGD-PEG modification enhanced the cytotoxicity of the DSPE-loaded ATO, attributable to increased uptake by U87 cells. Live/dead and apoptosis assays demonstrated that iRGD-PEG-ATO increased apoptosis by approximately 60% compared to free ATO. Furthermore, iRGD-PEG-ATO extended the plasma half-life by about 1-fold and significantly improved antitumor efficacy compared to free ATO. Treatment with iRGD-PEG-ATO prolonged the survival of tumor-bearing mice by approximately 2-fold relative to free ATO. Transcriptome sequencing indicated downregulation of the TGFBR2 gene in the nanomaterial-treated group, suggesting involvement of the MAPK pathway. Additionally, temozolomide was found to enhance the efficacy of the nanomaterial, which was corroborated by WB and IHC analyses.
Conclusion
The developed iRGD-PEG-ATO nanocarrier effectively crosses the BBB, accumulates within glioma cells, and releases its drug payload. This study demonstrates that iRGD-PEG-ATO enhances the antitumor efficacy of ATO against glioma, offering a promising targeted therapeutic strategy.