An injectable signal-amplifying device elicits a specific immune response against malignant glioblastoma

Targeting the glioblastoma resection margin with locoregional nanotechnologies

Surgical resection is the first stage of treatment for patients diagnosed with resectable glioblastoma and is followed by a combination of adjuvant radiotherapy and systemic single-agent chemotherapy, which is typically commenced 4-6 weeks after surgery. This delay creates an interval during which residual tumour cells residing in the resection margin can undergo uninhibited proliferation and further invasion, even immediately after surgery, thus limiting the effectiveness of adjuvant therapies. Recognition of the postsurgical resection margin and peri-marginal zones as important anatomical clinical targets and the need to rethink current strategies can galvanize opportunities for local, intraoperative approaches, while also generating a new landscape of innovative treatment modalities. In this Perspective, we discuss opportunities and challenges for developing locoregional therapeutic strategies to target the glioblastoma resection margin as well as emerging opportunities offered by nanotechnology in this clinically transformative setting. We also discuss how persistent barriers to clinical translation can be overcome to offer a potential path forward towards broader acceptability of such advanced technologies.

Tumor signal amplification and immune decoy strategy using bacterial membrane-coated nanoparticles for immunotherapy

In cancer therapy, tumor cells can diminish their signals through mechanisms such as immune escape, thereby evading recognition and elimination by the immune system. Providing tumor signals to enhance the recognition of tumor sites is considered a crucial approach in cancer treatment. Inspired by the decoy-induced directed feeding of fish, we propose a biomimetic nanoparticle system for tumor signal amplification. This biomimetic system comprises magnetically responsive nanoparticles and immune-inducing bacterial membranes. These designs work together to create a baiting effect at the tumor site, attracting and activating immune cells to attack. It has been demonstrated that the generated nanoparticles have the potential to be targeted and delivered to the tumor site under the influence of an external magnetic field, as demonstrated in preliminary in vitro and in vivo studies. Moreover, the nanoparticles utilize the bacterial membrane and cell membrane-translocated calreticulin to induce an immune response, simulating a decoy mechanism to recruit immune cells. The nanoparticles were proved to be effective in recruiting macrophages and neutrophils and reducing tumor size in animal experiments. These features make the nanoparticles an ideal candidate for treating tumors.

Glioblastoma Therapy: Past, Present and Future

Glioblastoma (GB) stands out as the most prevalent and lethal form of brain cancer. Although great efforts have been made by clinicians and researchers, no significant improvement in survival has been achieved since the Stupp protocol became the standard of care (SOC) in 2005. Despite multimodality treatments, recurrence is almost universal with survival rates under 2 years after diagnosis. Here, we discuss the recent progress in our understanding of GB pathophysiology, in particular, the importance of glioma stem cells (GSCs), the tumor microenvironment conditions, and epigenetic mechanisms involved in GB growth, aggressiveness and recurrence. The discussion on therapeutic strategies first covers the SOC treatment and targeted therapies that have been shown to interfere with different signaling pathways (pRB/CDK4/RB1/P16ink4, TP53/MDM2/P14arf, PI3k/Akt-PTEN, RAS/RAF/MEK, PARP) involved in GB tumorigenesis, pathophysiology, and treatment resistance acquisition. Below, we analyze several immunotherapeutic approaches (i.e., checkpoint inhibitors, vaccines, CAR-modified NK or T cells, oncolytic virotherapy) that have been used in an attempt to enhance the immune response against GB, and thereby avoid recidivism or increase survival of GB patients. Finally, we present treatment attempts made using nanotherapies (nanometric structures having active anti-GB agents such as antibodies, chemotherapeutic/anti-angiogenic drugs or sensitizers, radionuclides, and molecules that target GB cellular receptors or open the blood-brain barrier) and non-ionizing energies (laser interstitial thermal therapy, high/low intensity focused ultrasounds, photodynamic/sonodynamic therapies and electroporation). The aim of this review is to discuss the advances and limitations of the current therapies and to present novel approaches that are under development or following clinical trials.