Nanoparticles as phytochemical carriers for cancer treatment: News of the last decade

Delivery of natural products via polysaccharide-based nanocarriers for cancer therapy: A review on recent advances and future challenges

Cancer, caused by uncontrolled proliferation of abnormal cells, has long been a global public health issue. For decades, natural products have been proven to be an essential source for novel anticancer drug discovery. But their instability, low solubility and bioavailability, poor targeting impede therapeutic efficacy. With the development of nanotechnology, nanomedicine delivery systems have emerged as promising strategies to improve bioavailability and enhance the therapeutic efficacy of drugs. However, constructing suitable nanocarrier is still a major challenge. Polysaccharides are extensively employed as carrier materials in nanomedicine delivery systems, owing to their unique physicochemical properties, biocompatibility and low immunogenicity. Polysaccharide-based nanomedicine delivery systems show high drug delivery efficiency, controlled drug release, and precise tumor targeting. This paper reviews influencing factors in the construction of polysaccharide-based nanocarriers and the application of polysaccharide-based nanocarriers for the delivery of natural products in treating various cancers. It focuses on their in vitro and in vivo anticancer efficacy and mechanisms. Furthermore, the review contrasts the capabilities and limitations of polysaccharide-based nanocarriers with traditional delivery methods, underlining their potential to enable targeted, reduced toxicity and excellent cancer treatment modalities. Finally, we discuss the current research limitations and future prospects in this emerging field.

Targeting anticancer immunity in melanoma tumour microenvironment: unleashing the potential of adjuvants, drugs, and phytochemicals

Melanoma poses a challenge in oncology because of its aggressive nature and limited treatment modalities. The tumour microenvironment (TME) in melanoma contains unique properties such as an immunosuppressive and high-density environment, unusual vasculature, and a high number of stromal and immunosuppressive cells. In recent years, numerous experiments have focused on boosting the immune system to effectively remove malignant cells. Adjuvants, consisting of phytochemicals, toll-like receptor (TLR) agonists, and cytokines, have shown encouraging results in triggering antitumor immunity and augmenting the therapeutic effectiveness of anticancer therapy. These adjuvants can stimulate the maturation of dendritic cells (DCs) and infiltration of cytotoxic CD8+ T lymphocytes (CTLs). Furthermore, nanocarriers can help to deliver immunomodulators and antigens directly to the tumour stroma, thereby improving their efficacy against malignant cells. The remodelling of melanoma TME utilising phytochemicals, agonists, and other adjuvants can be combined with current modalities for improving therapy outcomes. This review article explores the potential of adjuvants, drugs, and their nanoformulations in enhancing the anticancer potency of macrophages, CTLs, and natural killer (NK) cells. Additionally, the capacity of these agents to repress the function of immunosuppressive components of melanoma TME, such as immunosuppressive subsets of macrophages, stromal and myeloid cells will be discussed.

Coprisin/Compound K Conjugated Gold Nanoparticles Induced Cell Death through Apoptosis and Ferroptosis Pathway in Adenocarcinoma Gastric Cells

Ferroptosis and apoptosis are programmed cell death pathways with distinct characteristics. Sometimes, cancer cells are aided by the induction of a different pathway, such as ferroptosis, when they develop chemoresistance and avoid apoptosis. Identifying the nanomedicine that targets dual pathways is considered as one of the best strategies for diverse cancer types. In our previous work, we synthesized gold nanoparticles (GNP) utilizing Gluconacetobacter liquefaciens in conjunction with compound K (CK) and coprisin (CopA3), yielding GNP-CK-CopA3. Here, we assessed the inhibitory effect of GNP-CK-CopA3 on AGS cells and the induction of apoptosis using Hoechst and PI, Annexin V-FITC/PI, and qRT-PCR. Subsequently, we conducted downstream proteomic analysis and molecular dynamic stimulation to identify the underlying molecular mechanisms. Our investigation of cultured AGS cells treated with varying concentrations of GNP-CK-CopA3 demonstrated the anticancer properties of these nanoparticles. Penetration of GNP-CK-CopA3 into AGS cells was visualized using an enhanced dark field microscope. Apoptosis induction was initially confirmed by treating AGS cells with GNP-CK-CopA3, as evidenced by staining with dyes such as Hoechst and PI. Additionally, mitochondrial disruption and cellular localization induced by GNP-CK-CopA3 were validated through Mito-tracker staining and transmission electron microscopy images. Annexin V-FITC/PI staining was used to distinguish early and late-stage apoptosis or necrosis based on fluorescence patterns. The gene expression of apoptotic markers indicated the initiation of cellular apoptosis. Further, proteomic analysis suggested that the treatment of GNP-CK-CopA3 to AGS cells led to the suppression of 439 proteins and the stimulation of 832 proteins. Among these, ferroptosis emerged as a significant interconnected pathway where glutathione peroxidase 4 (GPX4) and glutathione synthetase (GSS) were significant interacting proteins. Molecular docking and dynamic simulation studies confirmed the binding affinity and stability between CopA3 and CK with GSS and GPX4 proteins, suggesting the role of GNP-CK-CopA3 in ferroptosis induction. Overall, our study showed GNP-CK-CopA3 could play a dual role by inducing apoptosis and ferroptosis to induce AGS cell death.

Green nanotech paradigm for enhancing sesquiterpene lactone therapeutics in cancer

In the field of cancer therapy, sesquiterpene lactones (SLs) derived from diverse Dicoma species demonstrate noteworthy bioactivity. However, the translation of their full therapeutic potential into clinical applications encounters significant challenges, primarily related to solubility, bioavailability, and precise drug targeting. Despite these obstacles, our comprehensive review introduces an innovative paradigm shift that integrates the inherent therapeutic properties of SLs with the principles of green nanotechnology. To overcome issues of solubility, bioavailability, and targeted drug delivery, eco-friendly strategies are proposed for synthesizing nanocarriers. Green nanotechnology has emerged as a focal point in addressing environmental and health concerns linked to conventional treatments. This progressive approach of green nanotechnology holds promise for the development of safe and sustainable nanomaterials, particularly in the field of drug delivery. This groundbreaking methodology signifies a pioneering advancement in the creation of novel and effective anticancer therapeutics. It holds substantial potential for transforming cancer treatment and advancing the landscape of natural product research.

Chitosan nanoparticles loaded with Foeniculum vulgare extract regulate retrieval of sensory and motor functions in mice

In this study, chitosan nanoparticles (CSNPs) encapsulating Foeniculum vulgare (FV) seed extract (SE) were prepared for the controlled delivery of bioactive phytoconstituents. The prepared CSNPs encapsulating FVSE as sustain-releasing nanoconjugate (CSNPs-FVSE) was used as a potent source of functional metabolites including kaempferol and quercetin for accelerated reclamation of sensory and motor functions following peripheral nerve injury (PNI). The nanoconjugate exhibited in vitro a biphasic diffusion-controlled sustained release of quercetin and kaempferol ensuring prolonged therapeutic effects. The CSNPs-FVSE was administered through gavaging to albino mice daily at a dose rate of 25 mg/kg body weight from the day of induced PNI till the end of the experiment. The conjugate-treatment induced a significant acceleration in the regain of motor functioning, evaluated from the sciatic function index (SFI) and muscle grip strength studies. Further, the hotplate test confirmed a significantly faster recuperation of sensory functions in conjugate-treated group compared to control. An array of underlying biochemical pathways regulates the regeneration under well-optimized glucose and oxidant levels. Therefore, oxidant status (TOS), blood glycemic level and total antioxidant capacity (TAC) were evaluated in the conjugate-treated group and compared with the controls. The treated subjects exhibited controlled oxidative stress and regulated blood sugars compared to the non-treated control. Thus, the nanoconjugate enriched with polyphenolics significantly accelerated the regeneration and recovery of functions after nerve lesions. The biocompatible nanocarriers encapsulating the nontoxic natural bioactive constitutents have great medicinal and economic value.

Control of polymer-protein interactions by tuning the composition and length of polymer chains

Nanomoduling the 3D shape and chemical functionalities in a synthetic polymer may create recognition cavities for biomacromolecule binding, which serves as an attractive alternative to natural antibodies with much less cost. To obtain fundamental understanding and predict molecular design rules of the polymer antibody, we analyze the complex structure between the biomarker protein epithelial cell adhesion molecule (EpCAM) and a series of polymer ligands via molecular dynamics (MD) simulations. For monomeric ligands, strong enrichment of aromatic residues in protein binding sites is revealed, in line with the reported observations for natural antibodies. Yet, for linear polymers with a growing degree of polymerization, for the first time, a drastic change is revealed on the type of enriched protein residues and the location of protein binding sites, driven by the increasing steric hindrance effect that makes the adsorption of the polymer in the protein exterior feasible. Varying the polymer length and monomeric composition also significantly affects the ligand binding affinity. Here, we have captured three distinct dependences of the ligand binding free energy on the degree of polymerization: for NIPAm based hydrophilic polymers, TBAm dominated hydrophobic polymers and AAc dominated charged polymers. These results can be rationalized by the complex structure and the composition of protein residues at the binding interface. The entire analysis demonstrates unique binding features for polymer ligands and the possibility to modulate their binding sites and affinity by engineering the polymer structure.

Effect of Inlet Air Temperature and Quinoa Starch/Gum Arabic Ratio on Nanoencapsulation of Bioactive Compounds from Andean Potato Cultivars by Spray-Drying

Nanoencapsulation of native potato bioactive compounds by spray-drying improves their stability and bioavailability. The joint effect of the inlet temperature and the ratio of the encapsulant (quinoa starch/gum arabic) on the properties of the nanocapsules is unknown. The purpose of this study was to determine the best conditions for the nanoencapsulation of these compounds. The effects of two inlet temperatures (96 and 116 °C) and two ratios of the encapsulant (15 and 25% w/v) were evaluated using a factorial design during the spray-drying of native potato phenolic extracts. During the study, measurements of phenolic compounds, flavonoids, anthocyanins, antioxidant capacity, and various physical and structural properties were carried out. Higher inlet temperatures increased bioactive compounds and antioxidant capacity. However, a higher concentration of the encapsulant caused the dilution of polyphenols and anthocyanins. Instrumental analyses confirmed the effective encapsulation of the nuclei in the wall materials. Both factors, inlet temperature, and the encapsulant ratio, reduced the nanocapsules' humidity and water activity. Finally, the ideal conditions for the nanoencapsulation of native potato bioactive compounds were determined to be an inlet temperature of 116 °C and an encapsulant ratio of 15% w/v. The nanocapsules obtained show potential for application in the food industry.

Phytochemical-Based Nanomedicine for Targeting Tumor Microenvironment and Inhibiting Cancer Chemoresistance: Recent Advances and Pharmacological Insights

Cancer remains the leading cause of death and rapidly evolving disease worldwide. The understanding of disease pathophysiology has improved through advanced research investigation, and several therapeutic strategies are being used for better cancer treatment. However, the increase in cancer relapse and metastatic-related deaths indicate that available therapies and clinically approved chemotherapy drugs are not sufficient to combat cancer. Further, the constant crosstalk between tumor cells and the tumor microenvironment (TME) is crucial for the development, progression, metastasis, and therapeutic response to tumors. In this regard, phytochemicals with multimodal targeting abilities can be used as an alternative to current cancer therapy by inhibiting cancer survival pathways or modulating TME. However, due to their poor pharmacokinetics and low bioavailability, the success of phytochemicals in clinical trials is limited. Therefore, developing phytochemical-based nanomedicine or phytonanomedicine can improve the pharmacokinetic profile of these phytochemicals. Herein, the molecular characteristics and pharmacological insights of the proposed phytonanomedicine in cancer therapy targeting tumor tissue and altering the characteristics of cancer stem cells, chemoresistance, TME, and cancer immunity are well discussed. Further, we have highlighted the clinical perspective and challenges of phytonanomedicine in filling the gap in potential cancer therapeutics using various nanoplatforms. Overall, we have discussed how clinical success and pharmacological insights could make it more beneficial to boost the concept of nanomedicine in the academic and pharmaceutical fields to counter cancer metastases and drug resistance.

Phytochemical-based nanodrugs going beyond the state-of-the-art in cancer management-Targeting cancer stem cells in the framework of predictive, preventive, personalized medicine

Cancer causes many deaths worldwide each year, especially due to tumor heterogeneity leading to disease progression and treatment failure. Targeted treatment of heterogeneous population of cells - cancer stem cells is still an issue in protecting affected individuals against associated multidrug resistance and disease progression. Nanotherapeutic agents have the potential to go beyond state-of-the-art approaches in overall cancer management. Specially assembled nanoparticles act as carriers for targeted drug delivery. Several nanodrugs have already been approved by the US Food and Drug Administration (FDA) for treating different cancer types. Phytochemicals isolated from plants demonstrate considerable potential for nanomedical applications in oncology thanks to their antioxidant, anti-inflammatory, anti-proliferative, and other health benefits. Phytochemical-based NPs can enhance anticancer therapeutic effects, improve cellular uptake of therapeutic agents, and mitigate the side effects of toxic anticancer treatments. Per evidence, phytochemical-based NPs can specifically target CSCs decreasing risks of tumor relapse and metastatic disease manifestation. Therefore, this review focuses on current outlook of phytochemical-based NPs and their potential targeting CSCs in cancer research studies and their consideration in the framework of predictive, preventive, and personalized medicine (3PM).

Use of gold nanoparticle-silibinin conjugates: A novel approach against lung cancer cells

Lung cancer presents one of the most challenging carcinomas with meager 5-year survival rates (less than 20%), high metastasis and high recurrence due to chemo- and radio- resistance. An alternative or complementation to existing prognosis modalities is the use of phytochemicals such as silibinin, which targets essential cytokines, angiogenic factors and transcription factors for a profound anti-tumor effect. However, the problems of low solubility in an aqueous physiological environment, poor penetration, high metabolism and rapid systemic clearance limit the therapeutic use of silibinin. Conjugation of gold nanoparticles (GNPs) with silibinin may overcome the above challenges along with distinct advantages of biocompatibility, optical properties for monitoring and causation of cytotoxicity in cancer cells. The current study thus aims to develop silibinin conjugated gold nanoparticles (Sb-GNPs) with pH responsive release in the cancer microenvironment, optimizing several parameters for its higher activity and further evaluate the nanoplatform for their efficacy in inducing cell death in vitro against A549 lung cancer cells. GNPs was synthesized using trisodium citrate dihydrate as the reducing agent and further used for the conjugation of silibinin. The synthesized GNPs were found to be monodispersed and spherical in shape. The silibinin was successfully conjugated with gold nanoparticles and long-term stability of GNPs and Sb-GNPs nanoconjugates in suspension phase was confirmed by FTIR and DLS. Anticancer properties of Sb-GNPs were confirmed by different assay using MTT, Trypan blue dye exclusion assay and cell cycle analysis assay. After conjugation of silibinin with GNPs, the efficacy of silibinin increased 4-5 times in killing the cancer cells. This is the first report on using silibinin gold nanoconjugate system for lung cancer therapy with promising future applications.

Sesquiterpenoid lactones as potential anti-cancer agents: an update on molecular mechanisms and recent studies

Plants-based natural compounds are well-identified and recognized chemoprotective agents that can be used for primary and secondary cancer prevention, as they have proven efficacy and fewer side effects. In today's scenario, when cancer cases rapidly increase in developed and developing countries, the anti-cancerous plant-based compounds become highly imperative. Among others, the Asteraceae (Compositae) family's plants are rich in sesquiterpenoid lactones, a subclass of terpenoids with wide structural diversity, and offer unique anti-cancerous effects. These plants are utilized in folk medicine against numerous diseases worldwide. However, these plants are now a part of the modern medical system, with their sesquiterpenoid lactones researched extensively to find more effective and efficient cancer drug regimens. Given the evolving importance of sesquiterpenoid lactones for cancer research, this review comprehensively covers different domains in a spectrum of sesquiterpenoid lactones viz (i) Guaianolides (ii) Pseudoguaianolide (iii) Eudesmanolide (iv) Melampodinin A and (v) Germacrene, from important plants such as Cynara scolymus (globe artichoke), Arnica montana (wolf weeds), Spilanthes acmella, Taraxacum officinale, Melampodium, Solidago spp. The review, therefore, envisages being a helpful resource for the growth of plant-based anti-cancerous drug development.

Novel pterostilbene-loaded pro-phytomicelles: preclinical pharmacokinetics, distribution, and treatment efficacy against acetaminophen-induced liver injury

A novel pro-phytomicelle formulation with small molecule phytochemicals as nanomaterials was developed for the oral delivery of pterostilbene (PTE).