Publicação
Local treatment of glioblastoma with a hydrogel designed to recruit and efficiently damage cancer cells
| Resumo: | Glioblastoma (GB) is the most lethal and common malignant primary brain tumor in adults. The standard treatment consists in a surgery aiming for maximum tumor resection, followed by radiotherapy and oral administration of temozolomide. Unfortunately, this combination therapy is not able to prevent tumor recurrence and patients have a median survival of 12-15 months after diagnosis. Considering the current serious limitations in GB therapy, there is an urgent need to develop an efficient treatment. This work describes the development of an innovative hydrogel to be administered immediately after tumor resection and to readily interact with the surrounding tissue. The hydrogel is based on hyaluronic acid (HA) functionalized with the peptide Arg-Gly-Asp-Ser (RGDS) and physically crosslinked with liposomes of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) encapsulating doxorubicin (DOX). HA is one of the main components of the brain extracellular matrix, while RGDS is a fibronectin inhibitory peptide that was used to enhance cells adhesive properties of HA and disrupt the interaction between integrins of GB cells and this protein. Liposomes present in the hydrogel matrix will allow the sustained release of DOX to efficiently damage GB cells. Moreover, the interaction of liposomes with cancer cell membranes can result in a favorable decrease of their fluidity, due to the presence of saturated phospholipids. Large unilamellar liposomes (LUVs) were prepared by the thin film hydration method, followed by extrusion. The homogeneous suspension of LUVs encapsulating DOX (polydispersity index ≈0.164) presented a size of ≈121.7 nm and a slightly negative surface charge (≈-2.43 mV). The concentration of DOX encapsulated in LUVs was relevant (≈68.2 μM for a phospholipid concentration of 1 mM) considering the IC50 results (≈3.82 μM for 24 h). The final hydrogel presented rheological properties similar to those of the brain tissue and was able to sustain the release of DOX along the experimental period considered (10 days). In vitro assays demonstrated the efficiency of non-functionalized HA hydrogels with liposomes encapsulating DOX to damage GB cells. Conversely, RGDS-functionalized HA hydrogels presented high cytotoxicity even without the incorporation of DOX. It was demonstrated that a metalloproteinase (MMP), namely MMP-2 expressed by GB cells, can break the bond between the peptide and HA. Nonetheless, the maximum peptide concentration present in the hydrogel was not cytotoxic for GB cells in 2D-culture, when in solution. Therefore, we hypothesized that a different scenario can be obtained if the peptide is released from the hydrogel where cells are adhered to. Notably, the RGDS-functionalized HA hydrogel incorporating liposomes with DOX was efficient in damaging GB cells without affecting the metabolism and viability of astrocytes, proving its safety. Overall, the results demonstrate the potential of this hydrogel as a future efficient GB treatment to dramatically improve the efficacy of the currently available treatments. |
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| Autores principais: | Ribeiro, Maria Leonor Rodrigues Castro |
| Assunto: | Doxorubicin Glioblastoma Hyaluronic acid hydrogel Liposomes RGDS peptide Doxorrubicina Glioblastoma Hidrogel de ácido hialurónico Lipossomas Péptido RGDS Engenharia e Tecnologia::Engenharia Médica |
| Ano: | 2021 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade do Minho |
| Idioma: | inglês |
| Origem: | RepositóriUM - Universidade do Minho |
| Resumo: | Glioblastoma (GB) is the most lethal and common malignant primary brain tumor in adults. The standard treatment consists in a surgery aiming for maximum tumor resection, followed by radiotherapy and oral administration of temozolomide. Unfortunately, this combination therapy is not able to prevent tumor recurrence and patients have a median survival of 12-15 months after diagnosis. Considering the current serious limitations in GB therapy, there is an urgent need to develop an efficient treatment. This work describes the development of an innovative hydrogel to be administered immediately after tumor resection and to readily interact with the surrounding tissue. The hydrogel is based on hyaluronic acid (HA) functionalized with the peptide Arg-Gly-Asp-Ser (RGDS) and physically crosslinked with liposomes of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) encapsulating doxorubicin (DOX). HA is one of the main components of the brain extracellular matrix, while RGDS is a fibronectin inhibitory peptide that was used to enhance cells adhesive properties of HA and disrupt the interaction between integrins of GB cells and this protein. Liposomes present in the hydrogel matrix will allow the sustained release of DOX to efficiently damage GB cells. Moreover, the interaction of liposomes with cancer cell membranes can result in a favorable decrease of their fluidity, due to the presence of saturated phospholipids. Large unilamellar liposomes (LUVs) were prepared by the thin film hydration method, followed by extrusion. The homogeneous suspension of LUVs encapsulating DOX (polydispersity index ≈0.164) presented a size of ≈121.7 nm and a slightly negative surface charge (≈-2.43 mV). The concentration of DOX encapsulated in LUVs was relevant (≈68.2 μM for a phospholipid concentration of 1 mM) considering the IC50 results (≈3.82 μM for 24 h). The final hydrogel presented rheological properties similar to those of the brain tissue and was able to sustain the release of DOX along the experimental period considered (10 days). In vitro assays demonstrated the efficiency of non-functionalized HA hydrogels with liposomes encapsulating DOX to damage GB cells. Conversely, RGDS-functionalized HA hydrogels presented high cytotoxicity even without the incorporation of DOX. It was demonstrated that a metalloproteinase (MMP), namely MMP-2 expressed by GB cells, can break the bond between the peptide and HA. Nonetheless, the maximum peptide concentration present in the hydrogel was not cytotoxic for GB cells in 2D-culture, when in solution. Therefore, we hypothesized that a different scenario can be obtained if the peptide is released from the hydrogel where cells are adhered to. Notably, the RGDS-functionalized HA hydrogel incorporating liposomes with DOX was efficient in damaging GB cells without affecting the metabolism and viability of astrocytes, proving its safety. Overall, the results demonstrate the potential of this hydrogel as a future efficient GB treatment to dramatically improve the efficacy of the currently available treatments. |
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