Enhanced BBB and BBTB penetration and improved anti-glioma behavior of Bortezomib through dual-targeting nanostructured lipid carriers

The effective treatment of glioma through conventional chemotherapy is proved to be a great challenge in clinics. The main reason is due to the existence of two physiological and pathological barriers respectively including the blood-brain barrier (BBB) and blood-brain tumor barrier (BBTB) that prevent most of the chemotherapeutics from efficient delivery to the brain tumors. To address this challenge, an ideal drug delivery system would efficiently traverse the BBB and BBTB and deliver the therapeutics into the glioma cells with high selectivity. Herein, a targeted delivery system was developed based on nanostructured lipid carriers (NLCs) modified with two proteolytically stable D-peptides, D8 and RI-VAP (Dual NLCs). D8 possesses high affinity towards nicotine acetylcholine receptors (nAChRs), overexpressed on brain capillary endothelial cells (BCECs), and can penetrate through BBB with high efficiency. RI-VAP is a specific ligand of cell surface GRP78 (csGRP78), a specific angiogenesis and cancer cell-surface marker, capable of circumventing the BBTB with superior glioma-homing property. Dual NLCs could internalize into BCECs, tumor neovascular endothelial cells, and glioma cells with high specificity and could penetrate through in vitro BBB and BBTB models with excellent efficiency compared to non-targeted or mono-targeted NLCs. In vivo whole-animal imaging and ex vivo imaging further confirmed the superior targeting capability of Dual NLCs towards intracranial glioma. When loaded with Bortezomib (BTZ), Dual NLCs attained the highest therapeutic efficiency by means of in vitro cytotoxicity and apoptosis and prolonged survival rate and anti-glioma behavior in intracranial glioma bearing mice. Collectively, the designed targeting platform in this study could overcome multiple barriers and effectively deliver BTZ to glioma cells, which represent its potential for advanced brain cancer treatment with promising therapeutic outcomes.

Filamentous Bacteriophage-A Powerful Carrier for Glioma Therapy

Glioma is a life-threatening malignant tumor. Resistance to traditional treatments and tumor recurrence present major challenges in treating and managing this disease, consequently, new therapeutic strategies must be developed. Crossing the blood-brain barrier (BBB) is another challenge for most drug vectors and therapy medications. Filamentous bacteriophage can enter the brain across the BBB. Compared to traditional drug vectors, phage-based drugs offer thermodynamic stability, biocompatibility, homogeneity, high carrying capacity, self-assembly, scalability, and low toxicity. Tumor-targeting peptides from phage library and phages displaying targeting peptides are ideal drug delivery agents. This review summarized recent studies on phage-based glioma therapy and shed light on the developing therapeutics phage in the personalized treatment of glioma.

Targeted delivery of miRNA based therapeuticals in the clinical management of Glioblastoma Multiforme

Glioblastoma multiforme (GBM) is the most aggressive (WHO grade IV) form of diffuse glioma endowed with tremendous invasive capacity. The availability of narrow therapeutic choices for GBM management adds to the irony, even the post-treatment median survival time is roughly around 14-16 months. Gene mutations seem to be cardinal to GBM formation, owing to involvement of amplified and mutated receptor tyrosine kinase (RTK)-encoding genes, leading to dysregulation of growth factor signaling pathways. Of-late, the role of different microRNAs (miRNAs) in progression and proliferation of GBM was realized, which lead to their burgeon potential applications for diagnostic and therapeutic purposes. miRNA signatures are intricately linked with onset and progression of GBM. Although, progression of GBM causes significant changes in the BBB to form BBTB, but still efficient passage of cancer therapeutics, including antibodies and miRNAs are prevented, leading to low bioavailability. Recent developments in the nanomedicine field provide novel approaches to manage GBM via efficient and brain targeted delivery of miRNAs either alone or as part of cytotoxic pharmaceutical composition, thereby modulating cell signaling in well predicted manner to promise positive therapeutic outcomes.

Liposomes and lipid disks traverse the BBB and BBTB as intact forms as revealed by two-step Förster resonance energy transfer imaging

The blood-brain barrier (BBB) and the blood-brain tumor barrier (BBTB) prevent drug and nano-drug delivery systems from entering the brain. However, ligand-mediated nano-drug delivery systems have significantly enhanced the therapeutic treatment of glioma. In this study we investigated the mechanism especially the integrity of liposomes and lipid disks while traversing the BBB and BBTB both in vitro and in vivo. Fluorophores (DiO, DiI and DiD) were loaded into liposomes and lipid disks to form Förster resonance energy transfer (FRET) nano-drug delivery systems. Using brain capillary endothelial cells as a BBB model, we show that liposomes and disks are present in the cytoplasm as their intact forms and traverse the BBB with a ratio of 0.68‰ and 1.67‰, respectively. Using human umbilical vein endothelial cells as BBTB model, liposomes and disks remained intact and traversed the BBTB with a ratio of 2.31‰ and 8.32‰ at 3 h. Ex vivo imaging and immunohistochemical results revealed that liposomes and disks could traverse the BBB and BBTB in vivo as intact forms. In conclusion, these observations explain in part the mechanism by which nano-drug delivery systems increase the therapeutic treatment of glioma.