The use of monocyte/macrophage (Ma) cells as a biomimetic drug delivery system can be attributed to their involvement in innate immunity and active tumor targeting, by chemotactic factors, to hypoxic regions where conventional therapies such as chemotherapy and radiation are least effective. Furthermore, their ability to readily bypass a partially compromised blood-brain barrier has influenced the utilization of Ma as delivery vectors for brain tumor therapies that can leave other tissues relatively unaffected. Previous studies have confirmed that Ma can efficiently deliver therapeutically meaningful chemotherapeutic concentrations to in-vitro glioma models with limited carrier cytotoxicity. The effectiveness of photochemical internalization (PCI), a light-based approach, by Ma-based vectorization of drug for tumors was investigated in this study.
Utilizing glioma and macrophage cell lines, in-vitro studies were conducted to demonstrate the increased efficacy of Ma-delivered chemotherapeutics. Preliminary data show that macrophages are resistant to chemotherapeutics while significant toxicity is observed for tumor cells exposed to the same drug. Further, co-incubation of tumor and Ma cells show significant tumor cell toxicity, suggestive of drug release by Ma. Treatment by PCI utilizing macrophage-mediated drug delivery was shown to enhance chemotherapeutic biological activity in comparison to drug treatment alone.
|