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Targeting Glioblastoma using Combinatorial Therapeutic Nanovaccine

Periodic Reporting for period 1 - GLIOMA (Targeting Glioblastoma using Combinatorial Therapeutic Nanovaccine)

Período documentado: 2017-10-02 hasta 2019-10-01

Glioblastoma (GBM) is one of the major malignant brain tumors seen. Patients with GBM and brain metastasis currently have less treatment options available. Existing therapies have many difficulties in the complete killing of GBM cells as they possess a mixed grade of cells. Certain cells within these highly malignant tumors may respond to primary therapies while others do not. GBMs are aggressive in nature with a near sure recurrence despite aggressive surgical resection and combinatorial chemoradiation. Increasing evidence suggests that these tumours harbour a brain tumour-initiating cell population that is resistant to radiation and current standard chemotherapy. Interestingly, this highly malignant population can be identified by specific cell markers. In this project a combinatorial strategy that represses tumour immune-evasion, and specifically targets the cancer cells which potentially could hinder recurrence and provide clinical benefit to glioma treatment was studied. The combination of immunotherapy with chemotherapy could enhance the antitumor efficacy by activating multilevel cancer killing mechanisms.
The main objectives of the project objectives were: i) development of a multipotent theragnostic nanovaccine (TNVax) for targeting GBM using hollow gold nanocages; ii) assessment of the anticancer potential of TNVax nanoparticles, and iii) assessment of the drug delivery and therapeutic efficiency of TNVax.
Combinatorial nanotherapeutics, implemented in project, is a novel idea for introducing targeted therapies to cancer killing. The project Glioma has foreseen the future of therapeutics and has conceptualized and executed a novel strategy in the field of nanodrug delivery. By combining chemo and immuno parameters in the same system, TNVax has shown the future of combination therapeutics. The TNVax prototype based on the gold nanocages has shown an ideal prototype feature for the formation of multi-functionalised nanoformulation possible for the targeted cancer therapy. The results have suggested the successful killing of glioma cells under invitro conditions with enormous characterisation techniques performed. The future prospects will be to enhance the release mechanism of drug from the complex followed by studying its efficacy and immunomodulation studies in real systems.
This project offers a strategic combinatorial therapeutic approach to target glioblastoma multiforme (GBM) through nanodrug delivery of a chemotherapeutic agent and monoclonal antibodies. The project design focuses on a pentavalent therapeutic nanovaccine formulation that can specifically target GBM using hollow gold nanoparticles (AuNPs). The main aim of this project is to develop a multipotent theragnostic nanovaccine (TNVax) for targeting malignant GBM cells. The TNVax was designed as follows: the hollow gold nanocages (AuNcgs) passivated with a extremophilic sulfated polysaccharide, Mauran (MR) that was chemically bound with 5-fluorouracil (5FU). This nano-complex was functionalised with anti-CD133 antibody and anti-PD- L1 antibody for specific targeting of CD133 antigen and inhibiting the immune suppression induced by PD-L1 expression in GBM, respectively. The proposed schematic representation of the synthesis demonstrating the step by step fabrication of nanoformulations is depicted in the attached figure.
Hollow AuNcgs coated with muran- 5-Fluorouracil complex were prepared and characterised. These nanocomplex (TNVax nanoparticles) were functionalised with anti-CD133 and anti-PD-L1 antibodies for targeting and functional properties. A detailed characterization of these nanoparticles were performed using various physical, chemical and biological methods. TNVax nanoparticles were tested for anticancer activities against GBM and specificity on targeting were tested. Apart from that the immunomodulation occurring at GBM microenvironment on TNVax treatment was also aimed. The activity of TNVax in tumour directed immune response and suppression of PD-L1 signalling was also aimed to determine. In vitro cell toxicity analysis of TNVax showed promising anticancer effect against GBM cells. However, the release of free drug, 5FU was observed less compared to its release as a small-molecule complex from the polysaccharide prodrug complex. The reason for this was well demonstrated using chemical characterisations using XPS. Targeting of GBM with TNVax was shown using microscopy and the pharmacokinetic (PK) model for TNVax release was also set-up and demonstrated. GBM tumour model was developed and growth kinetics of GL261 cells to form tumour was studied using C57BL6 mice. However, in vivo efficacy and immunostimulation needs to be completed as the formulation requires certain chemical alterations in the synthetic process. The results achieved were disseminated through conferences, seminars, workshops, social media and web pages.
Combination therapy is the most modern approach in the novel therapeutics. Introduction of immuno and chemo parameters in the same formulation is a novel approach for cancer therapy. Application of nanotechnology platform for the delivery of combination formulation to a targeted cancer site has increased the chances of attacking the cancer cells precisely. Application of gold nanoparticles has increased the possibility of crossing a blood brain barrier as well. Existing therapies have many difficulties in completely killing GBM cells, as they possess a mixed grade of cells. Certain cells within these highly malignant tumours may respond to primary therapies while others will not. These difficulties can only be countered through combinatorial therapies with powerful chemotherapeutic agents and immunogens that kill cancer cells and leave durable immunological memory to prevent its recurrence, respectively. The development of TNVax formulation has widened the future of nanotechnology based combinatorial formulations. This prototype therapeutic formulation is a model for future vaccine types against cancer. Results obtained from the project Glioma is interesting and encouraging for further studies related to TNVax therapeutic formulation towards vaccine development. By employing nanotechnology science has proved that the nanoparticles below 100nm can pass the blood brain barrier. This has enabled us to think about gold nanoparticles to target the brain tumors and delivery drugs across BBB. Such formulation will be having a greater socio-economic impact as the cancer therapy will be revolutionised with such modern strategic approach that enabled both chemo and immunotherapeutic platforms. The project has future prospect in revolutionising the cancer therapy by introducing various things into single combination form like natural adjuvant polymers, poorly bioavailable drugs, antibodies, and nanocarrier vehicle. The multidisciplinary project Glioma has set goals and demonstrated strategic implications that will have a huge impact over the biomedicine and immunotherapy of cancers and vaccine development.
Schematic representation of the synthesis of the TNVax nanoparticles using microwave heating method,