Thermosensitive injectable hydrogel based on Pluronic F127-Polysacharide containing Melphalan and Topotecan for Retinoblastoma Treatment
Shaghayegh Fallah1 , Masoud Nasseripour2 , Hamid Sadeghi Abandansari3 , Leila Satarian1 *
- 1. Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran.
- 2. Department of Ophthalmology, Faculty of Medical Science, Iran University, Tehran, Iran.
- 3. Department of Cell Engineering, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran. 4. Department of Cancer Medicine, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Babol, Iran.
Abstract: Chemotherapy is the standard treatment for retinoblastoma, often utilizing a triadic regimen. A novel approach for managing vitreous seeds in this condition is super-selective intra-arterial chemotherapy. For intravitreal injections, the recommended dosage of Melphalan is approximately 20 µg, as higher doses can cause severe toxicity, including cataracts, vitreous hemorrhage and subretinal hemorrhage. Additionally, Topotecan has proven effective for retinoblastoma. Studies suggest that combining intravitreal Topotecan and Melphalan may enhance treatment efficacy and reduce the number of necessary injections, offering promise for better management of vitreous seeds. Moreover, hydrogels are being explored to diminish the side effects of conventional chemotherapy and lesser the frequency of injections.
Methods: In this study a thermosensitive hydrogel was prepared under sterile conditions by mixing Pluronic F127 with polysaccharide at 4°C overnight for complete dissolution. The hydrogel's internal structure was examined using scanning electron microscopy (SEM), while the sol-gel transition was assessed with the inverted tube method. In vitro degradation was evaluated via the gravimetric method. Rheological properties were determined through frequency and temperature sweep tests. For drug loading, Melphalan was incorporated into Pluronic F127 micelles using thin-film hydration. The Melphalan concentration in micelles was measured using UV-Vis spectrophotometry, and drug loading content (DLC) was calculated. The cytotoxic effects of Melphalan and Topotecan, both individually and in combination, were evaluated on Y79 cells using the MTS assay.
Results: The Pluronic F127-Polysaccharide hydrogels were successfully synthesized, demonstrating a consistent sol-to-gel transition at body temperature. Scanning electron microscopy revealed an interconnected, porous microstructure. In vitro degradation showed that hydrogels degraded over six days, suitable for controlled drug delivery. Rheological tests confirmed elastic behavior (G' > G"), indicative of shape retention. The DLC of Melphalan was 9.25%. When combined, Melphalan and Topotecan exhibited synergistic cytotoxic effects, increasing cell death in Y79 retinoblastoma cells compared to individual drug treatments.
Conclusion: These results suggest that Pluronic F127-Polysaccharide hydrogels hold potential for effective and sustained intravitreal drug delivery. Future research will aim to confirm their preclinical significance in improving retinoblastoma treatment.
