Periodic Reporting for period 1 - microMESH (Preclinical validation and market analysis of a microMESH implant for brain cancer eradication)
Periodo di rendicontazione: 2022-07-01 al 2024-12-31
Glioblastoma (GBM) is the most aggressive and common malignant brain tumor, with an incidence of about 5 cases per 100,000 people annually. Despite aggressive treatment, including surgery, radiation, and chemotherapy, the median survival remains well below 2 years, with a 5-year survival rate of 5%. Major challenges in treating GBM are the blood-brain barrier (BBB), which limits drug delivery; biological heterogeneity. In this Proof of Concept, engineers, biotechnologists, and technology-transfer experts demonstrated that microMESH, a novel drug delivery implant, can deploy intracranially chemo-immunotherapies to eradicate GBM and reduce its long-term complications. Designed to deliver taxanes and antibodies for immune check points’ inhibition – therapeutic agents that normally cannot cross the blood-brain barrier – microMESH ensures their uniform, deep, and sustained intratumor permeation. This PoC led to a preclinically validated microMESH for treating newly diagnosed and recurrent GBM and is now driving the launch of a biotech startup to advance its development from the lab to the clinic.
microMESH was fabricated through a top-down soft lithography approach. microMESH consists of a hydrophilic PVA microlayer supporting a hydrophobic PLGA micronetwork, which enabled the precise compartmentalization of multiple therapeutic agents, including small molecules, inhibitors, chemotherapeutic drugs, peptides, proteins, antibodies, and nanomedicines. In this proof of concept, microMESH was loaded with anti-CD47 monoclonal antibodies in the PVA microlayer and docetaxel (DTXL) within the PLGA strands, allowing for controlled and uniform drug distribution with high encapsulation efficiencies. The release profile demonstrated that DTXL was gradually delivered over months, while anti-CD47 was released within the first week, preserving its structural integrity and binding affinity. For in vitro therapeutic efficacy, anti-CD47 blocked the ‘do-not-eat-me’ signal on GBM cells, enabling macrophages to recognize and eliminate them. CT2A glioblastoma cells were treated with free or microMESH-loaded anti-CD47, then co-incubated with macrophages, where bioluminescence assays confirmed that higher anti-CD47 doses enhanced macrophage phagocytosis, reducing tumor cell viability. Confocal imaging supported these findings, showing reduced tumor presence at higher anti-CD47 concentrations. The cytotoxic potential of DTXL was assessed in CT2A cells, revealing dose- and time-dependent tumor cell death, and its combination with anti-CD47 in the presence of macrophages further enhanced tumor clearance. After extensive in vitro characterizations, microMESH was tested in vivo in a rigorous preclinical model of a highly aggressive syngeneic GBM model. Tumor growth was monitored via bioluminescence imaging, and nine experimental groups were evaluated, including control, free drug, and low- or high-dose microMESH treatments with DTXL alone, anti-CD47 alone, and their combination. Kaplan-Meier survival analysis showed that free DTXL and anti-CD47 had limited impact, whereas microMESH achieved the longest median survival, confirming the synergy between anti-CD47 and DTXL.
The microMESH platform has demonstrated significant advancements beyond the state of the art, having been successfully loaded with a variety of therapeutic agents, including chemotherapeutic drugs, small anti-inflammatory molecules, small-molecule inhibitors, monoclonal antibodies as well as polymeric nanoparticles. It has been fabricated in multiple geometries, with openings featuring side edge lengths ranging from 5 µm to 100 µm, and manufactured using diverse materials and their combinations. A key distinguishing feature of microMESH is its ability to deform and conform to complex biological surfaces, ensuring the uniform and deep intratumoral distribution of therapeutic agents. In preclinical models, microMESH has achieved complete tumor regression in partially resected glioblastoma models established through intracranial inoculation of cells line and patient-derived glioblastoma cancer stem cells. Furthermore, in unresected glioblastoma models, microMESH has significantly extended survival and, in some cases, led to complete tumor eradication.