Aparajita Bhattacharya

Protein‐based nanocarriers bear highly desirable properties such as biodegradability and the ability to facilitate passage through biological barriers such as the blood–brain‐barrier. Using modular protein engineering, we develop a strategy for iteratively improving the delivery efficacy of hydrophobic small molecules for the treatment of glioblastoma multiforme (GBM). By increasing the multiplicity m of the coiled‐coil and RGD peptide targeting regions from 1 to 2, we can increase both the hydrodynamic micellar size and drug loading capacity of the targeted multidomain protein assembly (TMPA) relative to its predecessor thermoresponsive assembled protein (TRAP). An upper limit of m is likely determined by steric interactions. TMPA shows a 1.7‐fold increase in doxorubicin (Dox) encapsulation compared to TRAP and demonstrates a 1.3‐fold improvement in uptake by U87 human GBM cells. Near‐infrared (NIR) dye‐labelled TMPA (NIR‐TMPA) is intravenously administered to mice orthotopically implanted with GBM cells and to control mice. Pharmacokinetic analysis using a 2‐compartment pharmacokinetic model reveals a significantly prolonged distribution‐phase (short‐phase) half‐life in tumor‐bearing mice compared to control, while the elimination‐phase (slow‐phase) half‐life remains comparable between groups. This suggests altered early‐phase kinetics likely due to tumor‐associated sequestration or retention. The resulting increased area under the concentration‐time curve (AUC) in tumor‐bearing mice supports enhanced accumulation or slower clearance. Ex vivo fluorescence imaging of organs and 3D reconstructions of whole mouse heads further corroboratesa preferential localization of NIR‐TMPA in tumor regions. These findings highlight the potential of TMPA and its future derivatives for targeted GBM therapy.

Protein‐based nanocarriers bear highly desirable properties such as biodegradability and the ability to facilitate passage through biological barriers such as the blood–brain‐barrier. Using modular protein engineering, we develop a strategy for iteratively improving the delivery efficacy of hydrophobic small molecules for the treatment of glioblastoma multiforme (GBM). By increasing the multiplicity m of the coiled‐coil and RGD peptide targeting regions from 1 to 2, we can increase both the hydrodynamic micellar size and drug loading capacity of the targeted multidomain protein assembly (TMPA) relative to its predecessor thermoresponsive assembled protein (TRAP). An upper limit of m is likely determined by steric interactions. TMPA shows a 1.7‐fold increase in doxorubicin (Dox) encapsulation compared to TRAP and demonstrates a 1.3‐fold improvement in uptake by U87 human GBM cells. Near‐infrared (NIR) dye‐labelled TMPA (NIR‐TMPA) is intravenously administered to mice orthotopically implanted with GBM cells and to control mice. Pharmacokinetic analysis using a 2‐compartment pharmacokinetic model reveals a significantly prolonged distribution‐phase (short‐phase) half‐life in tumor‐bearing mice compared to control, while the elimination‐phase (slow‐phase) half‐life remains comparable between groups. This suggests altered early‐phase kinetics likely due to tumor‐associated sequestration or retention. The resulting increased area under the concentration‐time curve (AUC) in tumor‐bearing mice supports enhanced accumulation or slower clearance. Ex vivo fluorescence imaging of organs and 3D reconstructions of whole mouse heads further corroboratesa preferential localization of NIR‐TMPA in tumor regions. These findings highlight the potential of TMPA and its future derivatives for targeted GBM therapy.