Paclitaxel-loaded hybrid exosome for targeted chemotherapy of triple-negative breast cancer

Abstract

Background: Triple-negative breast cancer (TNBC) is a highly invasive malignant tumor with bleak prognosis.Paclitaxel (PTX) is the first-line chemotherapeutic drug for TNBC management. It is of great significance to develop carriers for targeted delivery of PTX to enhance the anti-tumor efficacy and reduce the side effects for TNBC management. Exosomes are small extracellular vesicles and emerging competent nanocarriers for targeted drug delivery. However, the application of exosomes has been challenged by the production, drug loading and quality control. The introduction of synthetic nanomaterials may help to overcome the limitations of exosomes and generate alternatives. Herein, we performed a biohybrid approach to fuse exosomeswith liposomes to produce hybrid exosome (HE) with improved PTX loading capacity and enhanced tumor-targeting ability for TNBC chemotherapy. Methods:HE and PTX-loaded HE (PTX-HE) were prepared by co-extrusion of exosomes with liposome (lipo) or PTX-loaded liposome (PTX-lipo) respectively. The size distribution of HE was measured by nanoparticle tracking analysis (NTA) and dynamic laser-light scattering (DLS). The morphology was observed by transmission electron microscopy (TEM). The protein profile of HE was determined by western blot and Coomassie Blue staining. Drug loading capacity and encapsulation efficiency were measured by high-performance liquid chromatography (HPLC). Cellular uptake, tumor cell killing effect and anti-migration ability of PTX-HE were evaluated in vitro. Biodistribution, anti-tumor therapeutic efficacy and safety of PTX-HE were evaluated in orthotopic TNBC mice models. Results:The characterization results manifested HE was spherical structure with uniform size distribution (157.28 nm). HE had improved loading capacity (6.20 ± 0.79%) and higher encapsulation efficiency (86.79 ± 11.07%) of PTX than lipo. More importantly, PTX-HE possessed higher cellular uptake efficiency, lower IC50 (4.32 ± 0.48 μg/mL) and stronger anti-migration ability (cell mobility: 16%) as compared with PTX-lipo. In TNBC-bearing mice, PTX-HE accumulated at tumor sites and suppressed tumor growth (tumor inhibition rate: 60%) with minimal systemic toxicity. Conclusions: HE exhibits improved drug loading capacity, targeting ability and cancer cell-killing effect. Overall, HE developed by fusing exosomes with liposomes provides a promising strategy for the large-scale generation of exosome alternatives as drug carriers for targeted chemotherapy.

Imaging of Light-Enhanced Extracellular Vesicle-Mediated Delivery of Oxaliplatin to Colorectal Cancer Cells via Laser Ablation, Inductively Coupled Plasma Mass Spectrometry

“…The approach here does not have a resolution to discriminate this, but further work to assess this is necessary in combination with work to establish the uptake, delivery and EV release mechanism. Drug loading efficiencies, assessed using either fluorometric assays or ICP-MS, were observed to be around 20% for doxorubicin, oxaliplatin and porphyrins, which is consistent with the range of loading efficiencies described by other groups [ 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 ]. Interestingly, because we used porphyrin molecules, which are fluorescent in part of this study, we were able to use single-particle nano-flow cytometry to further characterize this, observing that the loading efficiency was a function of loading concentration but that this was linked to the number of particles loaded, rather than as may be expected, the amount of drug loading into each EV.…”

“…The delivery of both oxaliplatin assessed using LA-ICP-MSI, C5SHU porphyrin assessed via fluorescence microscopy, alongside brightfield microscopy and overlaying ICP-MS signal with the physiological signal Mg 24 showed that drugs were detectable intracellularly within 3 h, and that by 24 h, uptake was generally saturated. Further, delivery using EVs delivered this payload more effectively within the 3 h time frame, consistent with previous work on platinum drugs, porphyrins and other drugs [ 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 ]. The ability of EVs to deliver drugs applied at similar concentrations to conventional delivery methods with greater, more rapid efficiency means they have great potential for clinical application.…”

“…The choice of “passive” methods (such as co-incubation) compared to “active” methods, including sonication and electroporation, needs to be a consideration depending on the polarity and size of the drug and will likely influence whether the cargo is internalised, incorporated or adsorbed onto the EV surface. Assessing loading and subsequent delivery requires analytical tools capable of the sensitive detection of the analyte under investigation, and fluorescent agents such as doxorubicin are readily detectable using fluorometry and fluorescence microscopy [ 24 , 25 , 26 , 27 , 28 , 29 ], but detecting non-fluorescent agents such as platinum-based drugs and analysis in tissues requires analytical equipment such as chromatography or mass spectrometry-based instrumentation [ 30 , 31 , 32 , 33 , 34 , 35 , 36 ].…”

Extracellular Vesicles in Breast Cancer: From Biology and Function to Clinical Diagnosis and Therapeutic Management

“…It holds the same for PTX, SEVs being more efficient than free PTX and liposomal PTX in inhibiting cancer cell growth [ 566 ]. However, developing SEV fusion with liposomes to produce a hybrid exosome (HE) with improved PTX loading capacity and enhanced tumor-targeting ability seems promising for triple-negative TNBC chemotherapy [ 567 ]. Loaded SEVs can overcome drug efflux transporter adverse effects, decreasing tumor metastasis compared to controls [ 568 ].…”