The synthesis and applications of boron nitride nanotubes and hexagonal boron nitrides as nanocarriers and therapeutic agents

In recent years, boron-based nanomaterials, boron nitride nanotubes and hexagonal boron nitrides (BNNTs and hBNs) have gained significant interest for their use in medical and biomedical fields owing to their nanometer size and unique physicochemical properties including biocompatibility, high mechanical strength and chemical stability. These properties make them particularly suitable nanomaterials for their interaction with biomacromolecules and variety of successful biomedical applications. This thesis aims at addressing drug carrying and therapeutic effects of BNNTs and hBNs. Considering their potential applications as drug carriers and therapeutic agents, the route of their interaction with biological environment should be understood at cellular level. Their biocompatibility evaluation revealed that the BNNTs and hBNs are good candidates for medical applications with their non-toxic nature on healthy cells even at relatively high concentrations. In an attempt to use the BNNTs and hBNs as drug carriers, they were modified with doxorubicin (Dox) and folate through nonspecific interactions. Folate was used to increase cellular uptake of BNNT by targeting folate receptors on the cell surface. It was found that the Dox conjugated BNNTs behave as the free Dox molecules while folate conjugation significantly enhanced (2 fold) cancerous cellular uptake. A purer and catalyst free hBNs batch was synthesized to use in the studies. Then, the hBNs were evaluated for their carrier and therapeutic effects. The data obtained from in vitro studies revealed that the level of reactive oxygen species (ROS) in the hBN exposed prostate cancer cells increased 62 per cent, cell death toward apoptosis was 4-fold enhanced and metastasis capacity of cells reduced significantly. These results envision the exploitation of hBNs as therapeutic agents against prostate cancer and pave the way to carry out in vivo studies to disclose their potential as drug carrier and therapeutic agents in cancer treatment.