Engineering a Biodegradable Nanocarrier for Enhancing the Response of T98G Cells to Temozolomide

Polymeric and small molecule-conjugates of temozolomide as improved therapeutic agents for glioblastoma multiforme

Temozolomide (TMZ), an imidazotetrazine, is a second-generation DNA alkylating agent used as a first-line treatment of glioblastoma multiforme (GBM). It was approved by FDA in 2005 and declared a blockbuster drug in 2008. Although TMZ has shown 100% oral bioavailability and crosses the blood-brain barrier effectively, however it suffers from limitations such as a short half-life (∼1.8 h), rapid metabolism, and lesser accumulation in the brain (∼10-20%). Additionally, development of chemoresistance has been associated with its use. Since it is a potential chemotherapeutic agent with an unmet medical need, advanced delivery strategies have been explored to overcome the associated limitations of TMZ. Nanocarriers including liposomes, solid lipid nanoparticles (SLNs), nanostructure lipid carriers (NLCs), and polymeric nanoparticles have demonstrated their ability to improve its circulation time, stability, tissue-specific accumulation, sustained release, and cellular uptake. Because of the appreciable water solubility of TMZ (∼5 mg/mL), the physical loading of TMZ in these nanocarriers is always challenging. Alternatively, the conjugation approach, wherein TMZ has been conjugated to polymers or small molecules, has been explored with improved outcomes in vitro and in vivo. This review emphasized the practical evidence of the conjugation strategy to improve the therapeutic potential of TMZ in the treatment of glioblastoma multiforme.

Hyaluronic Acid-Conjugated Nanoparticles for the Targeted Delivery of Cabazitaxel to CD44-Overexpressing Glioblastoma Cells

In decades, the efficiency of glioma therapy is far from satisfaction due to the inability of most therapeutics to accumulate at the glioblastoma (GBM) site. Therefore, it is urgent to develop novel tumor-targeted delivery systems for more optimized and effective glioma treatment. In this study, hyaluronic acid modified MPEG-PDLLA polymer (HAML) nanoparticles were used to encapsulate the cabazitaxel (Cab), creating Cab loaded HAML nanoparticles (Cab/HAML NPs) for glioma therapy both in vitro and in vivo. MTT assay and apoptotic study indicated Cab/HAML NPs induced a significant cell growth inhibition and more apoptosis of C6 cells than free Cab in vitro. In vivo study showed that Cab/HAML NPs could significantly improve chemotherapeutic effect to C6 tumor-bearing rats compared with free Cab. The median survival rate of Cab/HAML NPs-treated groups (30 days) was remarkably longer than the other groups treated with control (20 days), free Cab (19 days) and Cab/ML NPs (26 days). Immunohistochemical analysis revealed that Cab/HAML NPs improved Cab’s anti-tumor effect via improvement of tumor cell apoptosis, inhibition of tumor cell proliferation and a significant decrease in tumor angiogenesis. Together, our study suggested that Cab/HAML NPs might show promise for application to glioma therapy.

A Review of Mesoporous Silica Nanoparticle Delivery Systems in Chemo-Based Combination Cancer Therapies

Chemotherapy is an important anti-tumor treatment in clinic to date, however, the effectiveness of traditional chemotherapy is limited by its poor selectivity, high systemic toxicity, and multidrug resistance. In recent years, mesoporous silica nanoparticles (MSNs) have become exciting drug delivery systems (DDS) due to their unique advantages, such as easy large-scale production, adjustable uniform pore size, large surface area and pore volumes. While mesoporous silica-based DDS can improve chemotherapy to a certain extent, when used in combination with other cancer therapies MSN based chemotherapy exhibits a synergistic effect, greatly improving therapeutic outcomes. In this review, we discuss the applications of MSN DDS for a diverse range of chemotherapeutic combination anti-tumor therapies, including phototherapy, gene therapy, immunotherapy and other less common modalities. Furthermore, we focus on the characteristics of each nanomaterial and the synergistic advantages of the combination therapies. Lastly, we examine the challenges and future prospects of MSN based chemotherapeutic combination therapies.