High therapeutic efficacy of 5-Fluorouracil-loaded exosomes against colon cancer cells

Extracellular vesicles in nanomedicine and regenerative medicine: A review over the last decade

Small extracellular vesicles (sEVs) are known to be secreted by a vast majority of cells. These sEVs, specifically exosomes, induce specific cell-to-cell interactions and can activate signaling pathways in recipient cells through fusion or interaction. These nanovesicles possess several desirable properties, making them ideal for regenerative medicine and nanomedicine applications. These properties include exceptional stability, biocompatibility, wide biodistribution, and minimal immunogenicity. However, the practical utilization of sEVs, particularly in clinical settings and at a large scale, is hindered by the expensive procedures required for their isolation, limited circulation lifetime, and suboptimal targeting capacity. Despite these challenges, sEVs have demonstrated a remarkable ability to accommodate various cargoes and have found extensive applications in the biomedical sciences. To overcome the limitations of sEVs and broaden their potential applications, researchers should strive to deepen their understanding of current isolation, loading, and characterization techniques. Additionally, acquiring fundamental knowledge about sEVs origins and employing state-of-the-art methodologies in nanomedicine and regenerative medicine can expand the sEVs research scope. This review provides a comprehensive overview of state-of-the-art exosome-based strategies in diverse nanomedicine domains, encompassing cancer therapy, immunotherapy, and biomarker applications. Furthermore, we emphasize the immense potential of exosomes in regenerative medicine.

Ataxia telangiectasia and Rad3-related (ATR) inhibition by VE-822 potently reversed 5-flourouracil resistance in colorectal cancer cells through targeting DNA damage response

BACKGROUND

VE-822 is a novel inhibitor of ATR, a key kinase involved in the DNA damage response pathway. The role of ATR inhibition in reversing drug resistance in various cancer types has been investigated. Therefore, this study investigated the effects of ATR inhibition by VE-822 on reversing 5-fluorouracil (5-FU) resistance in colorectal cancer cell line (Caco-2).

METHODS

Caco-2 and 5-FU resistance Caco-2 (Caco-2/5-FU) cells were treated with 5-FU and VE-822, alone and in combination. Cell proliferation and viability were assessed by MTT assay and Trypan Blue staining. P-glycoprotein (P-gp) and multidrug resistance-associated protein 1 (MRP1) activities were measured by Rhodamine123 accumulation and uptake assay. The mRNA levels of P-gp, MRP-1, ataxia telangiectasia and Rad3-related (ATR) and checkpoint kinase 1 (CHK1) were measured by qRT-PCR. Western blot was used to measure the protein levels of P-gp, MRP-1, γ-H2AX, ATR and CHK1 in cells. 8-Oxo-2'-deoxyguanosine (8-oxo-dG) levels were determined via ELISA. Apoptosis was evaluated by ELISA death assay, DAPI staining and lactate dehydrogenase (LDH) assay.

RESULTS

The Caco-2/5-FU cells showed lower levels of 5-FU mediated proliferation inhibition in comparison to Caco-2 cells. VE-822 decreased the IC50 value of 5-FU on resistant cells. In addition, the expression levels and activity of P-gp and MRP-1 were significantly decreased in resistant cells treated with VE-822 (P < 0.05). The combination of 5-FU and VE-822 increased apoptosis in Caco-2/5-FU cells by downregulating CHK1 and ATR and upregulating γ-H2AX and 8-oxo-dG.

CONCLUSION

The simultaneous treatment of resistant colorectal cancer cells with 5-FU and ATR inhibitor, VE-822, was demonstrated to be effective in reversing drug resistance and potentiating 5-FU mediated anticancer effects via targeting DNA damage.

Encapsulation and assessment of therapeutic cargo in engineered exosomes: a systematic review

Exosomes are nanoscale extracellular vesicles secreted by cells and enclosed by a lipid bilayer membrane containing various biologically active cargoes such as proteins, lipids, and nucleic acids. Engineered exosomes generated through genetic modification of parent cells show promise as drug delivery vehicles, and they have been demonstrated to have great therapeutic potential for treating cancer, cardiovascular, neurological, and immune diseases, but systematic knowledge is lacking regarding optimization of drug loading and assessment of delivery efficacy. This review summarizes current approaches for engineering exosomes and evaluating their drug delivery effects, and current techniques for assessing exosome drug loading and release kinetics, cell targeting, biodistribution, pharmacokinetics, and therapeutic outcomes are critically examined. Additionally, this review synthesizes the latest applications of exosome engineering and drug delivery in clinical translation. The knowledge compiled in this review provides a framework for the rational design and rigorous assessment of exosomes as therapeutics. Continued advancement of robust characterization methods and reporting standards will accelerate the development of exosome engineering technologies and pave the way for clinical studies.

Engineering Exosomes to Specifically Target the Mitochondria of Brain Cells

Mitochondrial dysfunction is associated with various health conditions, including cardiovascular and neurodegenerative diseases. Mitochondrial-targeting therapy aims to restore or enhance mitochondrial function to treat or alleviate these conditions. Exosomes, small vesicles that cells secrete, containing a variety of biomolecules, are critical in cell-to-cell communication and have been studied as potential therapeutic agents. Exosome-based therapy has the potential to treat both cardiovascular and neurodegenerative diseases. Combining these two approaches involves using exosomes as carriers to transport mitochondrial-targeting agents to dysfunctional or damaged mitochondria within target cells. This article presents a new technique for engineering brain-derived exosomes that target mitochondria and has demonstrated promise in initial tests with primary neuron cells and healthy rats. This promising development represents a significant step forward in treating these debilitating conditions.

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

Extracellular vesicles (EVs) are lipid bilayer structures released by all cells that mediate cell-to-cell communication via the transfer of bioactive cargo. Because of the natural origin of EVs, their efficient uptake by recipient cells, capacity to stabilize and transport biomolecules and their potential for cell/tissue targeting and preferential uptake by cancer cells, they have enormous potential for bioengineering into improved and targeted drug delivery systems. In this work, we investigated the use of laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) as a tool to measure the loading of platinum-based chemotherapeutic agents. The EV loading of oxaliplatin via co-incubation was demonstrated, and LA-ICP-MS imaging showed greater efficiency of delivery to colorectal cancer cells compared to free oxaliplatin, leading to enhanced cytotoxic effect. Further, the impact of EV co-loading with a porphyrin (C5SHU, known as 'C5') photosensitizer on oxaliplatin delivery was assessed. Fluorescence analysis using nano-flow cytometry showed dose-dependent EV loading as well as a trend towards the loading of larger particles. Exposure of OXA-C5-EV-treated colorectal cancer cells to light indicated that delivery was enhanced by both light exposure and porphyrins, with a synergistic effect on cell viability observed between oxaliplatin, EVs and light exposure after the delivery of the co-loaded EVs. In summary, this work demonstrates the utility of LA-ICP-MS and mass spectrometry imaging in assessing the loading efficiency and cellular delivery of platinum-based therapeutics, which would also be suitable for agents containing other elements, confirms that EVs are more efficient at delivery compared to free drugs, and describes the use of light exposure in optimizing delivery and therapeutic effects of EV-mediated drug delivery both in combination and independently of porphyrin-based photosensitizers.