Work

A Scalable Method for Squalenoylation and Assembly of Multifunctional 64Cu-Labeled Squalenoylated Gemcitabine Nanoparticles

Year: 2018

Type: article

Abstract: Squalenoylation of gemcitabine, a front-line therapy for pancreatic cancer, allows for improved cellular-level and system-wide drug delivery.The established methods to conjugate squalene to gemcitabine and to form nanoparticles (NPs) with the squalenoylated gemcitabine (SqGem) conjugate are cumbersome, time-consuming and can be difficult to reliably replicate.Further, the creation of multi-functional SqGem-based NP theranostics would facilitate characterization of in vivo pharmacokinetics and efficacy.Methods: Squalenoylation conjugation chemistry was enhanced to improve reliability and scalability using tert-butyldimethylsilyl (TBDMS) protecting groups.We then optimized a scalable microfluidic mixing platform to produce SqGem-based NPs and evaluated the stability and morphology of select NP formulations using dynamic light scattering (DLS) and transmission electron microscopy (TEM).Cytotoxicity was evaluated in both PANC-1 and KPC (Kras LSL-G12D/+ ; Trp53 LSL-R172H/+ ; Pdx-Cre) pancreatic cancer cell lines.A 64 Cu chelator (2-S-(4-aminobenzyl)-1,4,7-triazacyclononane-1,4,7triacetic acid, NOTA) was squalenoylated and used with positron emission tomography (PET) imaging to monitor the in vivo fate of SqGem-based NPs.Results: Squalenoylation yields of gemcitabine increased from 15% to 63%.Cholesterol-PEG-2k inclusion was required to form SqGem-based NPs using our technique, and additional cholesterol inclusion increased particle stability at room temperature; after 1 week the PDI of SqGem NPs with cholesterol was ~ 0.2 while the PDI of SqGem NPs lacking cholesterol was ~ 0.5.Similar or superior cytotoxicity was achieved for SqGem-based NPs compared to gemcitabine or Abraxane® when evaluated at a concentration of 10 µM.Squalenoylation of NOTA enabled in vivo monitoring of SqGem-based NP pharmacokinetics and biodistribution.Conclusion: We present a scalable technique for fabricating efficacious squalenoylatedgemcitabine nanoparticles and confirm their pharmacokinetic profile using a novel multifunctional 64 Cu-SqNOTA-SqGem NP.

Source: Nanotheranostics

DOI: 10.7150/ntno.26969