A pH-Induced Reversible Assembly System with Resveratrol-Controllable Loading and Release for Enhanced Tumor-Targeting Chemotherapy

ULK1 Mediated Autophagy-Promoting Effects of Rutin-Loaded Chitosan Nanoparticles Contribute to the Activation of NF-κB Signaling Besides Inhibiting EMT in Hep3B Hepatoma Cells

Background

Liver cancer remains to be one of the leading causes of cancer worldwide. The treatment options face several challenges and nanomaterials have proven to improve the bioavailability of several drug candidates and their applications in nanomedicine. Specifically, chitosan nanoparticles (CNPs) are extremely biodegradable, pose enhanced biocompatibility and are considered safe for use in medicine.

Methods

CNPs were synthesized by ionic gelation, loaded with rutin (rCNPs) and characterized by ultraviolet-visible spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy (FTIR), dynamic light scattering (DLS) and transmission electron microscopy (TEM). The rCNPs were tested for their cytotoxic effects on human hepatoma Hep3B cells, and experiments were conducted to determine the mechanism of such effects. Further, the biocompatibility of the rCNPs was tested on L929 fibroblasts, and their hemocompatibility was determined.

Results

Initially, UV-vis and FTIR analyses indicated the possible loading of rutin on rCNPs. Further, the rutin load was quantitatively measured using Ultra-Performance Liquid Chromatography (UPLC) and the concentration was 88 µg/mL for 0.22 micron filtered rCNPs. The drug loading capacity (LC%) of the rCNPs was observed to be 13.29 ± 0.68%, and encapsulation efficiency (EE%) was 19.55 ± 1.01%. The drug release was pH-responsive as 88.58% of the drug was released after 24 hrs at the lysosomal pH 5.5, whereas 91.44% of the drug was released at physiological pH 7.4 after 102 hrs. The cytotoxic effects were prominent in 0.22 micron filtered samples of 5 mg/mL rutin precursor. The particle size for the rCNPs at this concentration was 144.1 nm and the polydispersity index (PDI) was 0.244, which is deemed to be ideal for tumor targeting. A zeta potential (ζ-potential) value of 16.4 mV indicated rCNPs with good stability. The IC50 value for the cytotoxic effects of rCNPs on human hepatoma Hep3B cells was 9.7 ± 0.19 μg/mL of rutin load. In addition, the increased production of reactive oxygen species (ROS) and changes in mitochondrial membrane potential (MMP) were observed. Gene expression studies indicated that the mechanism for cytotoxic effects of rCNPs on Hep3B cells was due to the activation of Unc-51-like autophagy-activating kinase (ULK1) mediated autophagy and nuclear factor kappa B (NF-κB) signaling besides inhibiting the epithelial-mesenchymal Transition (EMT). In addition, the rCNPs were less toxic on NCTC clone 929 (L929) fibroblasts in comparison to the Hep3B cells and possessed excellent hemocompatibility (less than 2% of hemolysis).

Conclusion

The synthesized rCNPs were pH-responsive and possessed the physicochemical properties suitable for tumor targeting. The particles were effectively cytotoxic on Hep3B cells in comparison to normal cells and possessed excellent hemocompatibility. The very low hemolytic profile of rCNPs indicates that the drug could be administered intravenously for cancer therapy.

Emerging natural polymer-based architectured nanotherapeutics for the treatment of cancer

The field of cancer therapy is advancing rapidly, placing a crucial emphasis on innovative drug delivery systems. The increasing global impact of cancer highlights the need for creative therapeutic strategies. Natural polymer-based nanotherapeutics have emerged as a captivating avenue in this pursuit, drawing substantial attention due to their inherent attributes. These attributes include biodegradability, biocompatibility, negligible toxicity, extended circulation time, and a wide range of therapeutic payloads. The unique size, shape, and morphological characteristics of these systems facilitate profound tissue penetration, complementing active and passive targeting strategies. Moreover, these nanotherapeutics exploit specific cellular and subcellular trafficking pathways, providing precise control over drug release kinetics. This comprehensive review emphasizes the utilization of naturally occurring polymers such as polysaccharides (e.g., chitosan, hyaluronic acid, alginates, dextran, and cyclodextrin) and protein-based polymers (e.g., ferritin, gelatin, albumin) as the foundation for nanoparticle development. The paper meticulously examines their in vitro characteristics alongside in vivo efficacy, particularly focusing on their pivotal role in ameliorating diverse types of solid tumors within cancer therapy. The amalgamation of material science ingenuity and biological insight has led to the formulation of these nanoparticles, showcasing their potential to reshape the landscape of cancer treatment.

Ferritin nanocage based delivery vehicles: From single-, co- to compartmentalized- encapsulation of bioactive or nutraceutical compounds

Bioactive or nutraceutical ingredients have been widely used in pursuit of health and well-being. However, the environmental instability, poor solubility and bioavailability, and unspecific delivery highly limited their practical values. By virtue of the unique shell-like structure, definite disassembly/reassembly behavior, and excellent safety profile of ferritin protein, it stands out among of various nano-materials and is emerging as one of the most promising vehicles for the encapsulation and delivery of bioactive ingredients or drugs. In this review, we present a systematic overview of recent advances of ferritin-based delivery systems from single-encapsulation, co-encapsulation, to compartmentalized-encapsulation of bioactive ingredients or drugs. Different encapsulation strategies for cargo loading as well as their advantages and drawbacks have been critically reviewed. This study emphasized the importance of the construction of compartmentalized delivery systems through the usage of ferritin nanocages, which exhibit great potential for facilitating the synergistic functionality of different types of cargos. Lastly, the applications of ferritin nanocages for physicochemical improvements and functionality achievements of loaded cargos are summarized. In conclusion, ferritin protein nanocages not only are excellent nanocarriers, but also can act as"multi-seated" vehicles for co-encapsulation and compartmentalized encapsulation of different cargos simultaneously.

Protein-Based Nanoparticles for the Imaging and Treatment of Solid Tumors: The Case of Ferritin Nanocages, a Narrative Review

Protein nanocages have been studied extensively, due to their unique architecture, exceptional biocompatibility and highly customization capabilities. In particular, ferritin nanocages (FNs) have been employed for the delivery of a vast array of molecules, ranging from chemotherapeutics to imaging agents, among others. One of the main favorable characteristics of FNs is their intrinsic targeting efficiency toward the Transferrin Receptor 1, which is overexpressed in many tumors. Furthermore, genetic manipulation can be employed to introduce novel variants that are able to improve the loading capacity, targeting capabilities and bio-availability of this versatile drug delivery system. In this review, we discuss the main characteristics of FN and the most recent applications of this promising nanotechnology in the field of oncology with a particular emphasis on the imaging and treatment of solid tumors.

Bioengineered Ferritin Nanocarriers for Cancer Therapy

Ferritin naturally exists in most organisms and can specifically recognize the transferrin 1 receptor (TfR1), which is generally highly expressed on various types of tumor cells. The pH dependent reversible assembling and disassembling property of ferritin renders it as a suitable candidate for encapsulating a variety of anticancer drugs and imaging probes. Ferritins external surface is chemically and genetically modifiable which can serve as attachment site for tumor specific targeting peptides or moieties. Moreover, the biological origin of these protein cages makes it a biocompatible nanocarrier that stabilizes and protects the enclosed particles from the external environment without provoking any toxic or immunogenic responses. Recent studies, further establish ferritin as a multifunctional nanocarrier for targeted cancer chemotherapy and phototherapy. In this review, we introduce the favorable characteristics of ferritin drug carriers, the specific targeted surface modification and a multifunctional nanocarriers combined chemotherapy with phototherapy for tumor treatment. Taken together, ferritin is a potential ideal base of engineered nanoparticles for tumor therapy and still needs to explore more on its way.

Opportunities for Persistent Luminescent Nanoparticles in Luminescence Imaging of Biological Systems and Photodynamic Therapy

The use of luminescence in biological systems allows us to diagnose diseases and understand cellular processes. Persistent luminescent materials have emerged as an attractive system for application in luminescence imaging of biological systems; the afterglow emission grants background-free luminescence imaging, there is no need for continuous excitation to avoid tissue and cell damage due to the continuous light exposure, and they also circumvent the depth penetration issue caused by excitation in the UV-Vis. This review aims to provide a background in luminescence imaging of biological systems, persistent luminescence, and synthetic methods for obtaining persistent luminescent materials, and discuss selected examples of recent literature on the applications of persistent luminescent materials in luminescence imaging of biological systems and photodynamic therapy. Finally, the challenges and future directions, pointing to the development of compounds capable of executing multiple functions and light in regions where tissues and cells have low absorption, will be discussed.

Curcumin-Loaded Nanoparticles with Low-Intensity Focused Ultrasound-Induced Phase Transformation as Tumor-Targeted and pH-Sensitive Theranostic Nanoplatform of Ovarian Cancer

We have developed a simple and versatile nanoplatform using pH-sensitive ferritin nanocages co-loaded with the anticancer drug curcumin (Cur) and liquid fluorocarbon perfluorohexane (PFH) inside the core and conjugated tumor-targeting molecule FA outside the shell referred to as FA-FCP. The synthesized FA-FCP has an average particle diameter of 47 nm, with stable and favorable physicochemical properties in different media, and high biocompatibility and biosafety in vivo and in vitro. Under the conditions of low-intensity focused ultrasound (LIFU) and at pH = 5.0, FA-FCP released a large amount of drugs (53.2%) in 24 h. After 4 min of LIFU (7 W) treatment, FA-FCP provided contrast-enhanced ultrasound imaging capabilities at pH = 5.0. Due to FA receptor-mediated endocytosis, FA-FCP could efficiently enter the cells and further relocate to lysosomes. Eighteen hours after injection of FA-FCP, the tumor was stimulated by LIFU, resulting in a contrast-enhanced ultrasound image. In vivo and in vitro experiments showed that the combined use of FA-FCP and LIFU had significant tumor treatment effects. Based on the results, it was concluded that FA-FCP combined with the external LIFU and the endogenic acidic environment can have powerful theranostic functions and provide a novel type of non-invasive and integrated tumor theranostic option.

Paclitaxel/IR1061-Co-Loaded Protein Nanoparticle for Tumor-Targeted and pH/NIR-II-Triggered Synergistic Photothermal-Chemotherapy

PURPOSE

The aim of this study was to develop an "all-in-one" nanoplatform that integrates at the second near-infrared (NIR-II) region dye IR1061 and anticancer drug paclitaxel (PTX) into an apoferritin (AFN) nanocage (IR-AFN@PTX). Simultaneously, folic acid (FA), tumor target molecule,  was conjugated onto IR-AFN@PTX to be IR-AFN@PTX-FA for tumor-targeted and pH/NIR-II-triggered synergistic photothermal-chemotherapy.

METHODS

IR1061 was firstly reacted with PEG and then conjugated with AFN to be IR-AFN. Then, FA was conjugated onto the surface of IR-AFN to be IR-AFN-FA. At last, PTX was incorporated into IR-AFN-FA to fabricate a nanoplatform IR-AFN@PTX-FA. The NIR-II photothermal properties and pH/NIR-II triggered drug release were evaluated. The ability of IR-AFN@PTX-FA to target tumors was estimated using optical bioluminescence. In vitro and in vivo synergistic therapeutic effects of pH/NIR-II-triggered and tumor-targeted photothermal-chemotherapy were investigated in 4T1 tumor model.

RESULTS

IR-AFN@PTX-FA showed excellent water solubility and physiological stability, which significantly enhanced the solubility of both IR1061 and PTX. After 5 min of laser irradiation at 1064 nm, IR-AFN@PTX-FA exhibited an effective photothermal effect compared with laser irradiation at 808 nm, even when blocked with 0.6 cm thick chicken breast. Cellular uptake experiments showed IR-AFN@PTX-FA utilized clathrin-mediated and caveolae-mediated endocytosis pathways to enter 4T1 cells, and was then delivered by the endosome to the lysosome. NIR-II laser irradiation and pH could synergistically trigger PTX release, inducing significant tumor inhibition in vitro and in vivo.

CONCLUSION

As a novel "all-in-one" nanoplatform, IR-AFN@PTX-FA was found to selectively target tumors and showed very efficient NIR-II photothermal effects and pH/NIR-II triggered drug release effects, showing a remarkable, synergistic photothermal-chemotherapy effect.

pH- and acoustic-responsive platforms based on perfluoropentane-loaded protein nanoparticles for ovarian tumor-targeted ultrasound imaging and therapy

In this study, we developed a multifunctional ultrasound (US) therapeutic agent that encapsulates perfluoropentane (PFP) into ferritin (FRT) and conjugates the tumor-targeting molecule folic acid (FA) (FA-FRT-PFP). The prepared FA-FRT-PFP had an average particle diameter of 42.8 ± 2.5 nm, a zeta potential of - 41.1 ± 1.7 mV and shows good stability in physiological solution and temperatures. FRT is a pH-sensitive cage protein that, at pH 5.0, disassembles to form pores that can load PFP. The adjustment to neutral pH closes the pores and encapsulates the PFP inside the FRT to form nanoparticles. At pH 5.0, 3 min of low-intensity focused ultrasound (LIFU, 2 W/cm2) significantly enhanced the US signal of FA-FRT-PFP through the acoustic droplet vaporization (ADV) effect. Under identical conditions, 4 min of LIFU irradiation caused the bubbles generated by FA-FRT-PFP to break. FA-FRT-PFP could be efficiently targeted into ovarian cancer cells and significantly enhanced the US contrast of FA-FRT-PFP after 3 min of LIFU irradiation. After 4 min of LIFU irradiation, cell viability significantly decreased due to necrosis, likely due to the FA-FRT-PFP mediated release of PFP in the acidic environment of lysosomes after entering the tumor cells. PFP is then transformed into bubbles that burst under LIFU irradiation, forming physical shock waves that lead to the destruction of the cell structure and necrosis, achieving tumor treatment. Taken together, this demonstrates that FA-FRT-PFP is both a novel and promising US theranostics agent for future clinic application.