Biocompatible gum arabic-gold nanorod composite as an effective therapy for mistreated melanomas

Recent advances in improved efficacies of gold nano-formulations in treatment of skin cancer: a systematic review

Skin cancer is the commonest malignancy for the population. Conventional skin cancer treatments include chemotherapy and surgery, but a large number of the chemotherapeutic drugs applied currently have undesirable possessions. The aim of this study is to provide a complete and acute assessment of the antitumor capability of gold nano-formulations in skin cancer as a new and more effectual delivery system for targeted therapy. In this systematic review, we conducted our first search in December 2021. In order to find related studies, 3 databases PubMed, Scopus and ScienceDirect. In order to maintain comprehensiveness in the search, no time limit was considered in the search process and finally the information obtained from the search was transferred to the information management software (EndNote). In order to maximize the number of articles that were related to our topic, a list of references identified in relevant articles was also manually searched and reviewed. Our final search was updated in late December 2021. There was evidence for a correlation between anticancer activities and treatment with gold nano-formulations. Additionally, studies shown that specific functionalization of the gold nanoparticles (Au NPs) which increase targetability to specific populations of cells could increase the application of Au NPs to the effective delivery of drugs to tumor cells. Our study demonstrated that gold nano-formulations are possible candidates for skin cancer treatment and might provide additional support for the clinical use of these anticancer agents in the future.

Brachytherapy at the nanoscale with protein functionalized and intrinsically radiolabeled [169Yb]Yb2O3 nanoseeds

PURPOSE

Classical brachytherapy of solid malignant tumors is an invasive procedure which often results in an uneven dose distribution, while requiring surgical removal of sealed radioactive seed sources after a certain period of time. To circumvent these issues, we report the synthesis of intrinsically radiolabeled and gum Arabic glycoprotein functionalized [169Yb]Yb2O3 nanoseeds as a novel nanoscale brachytherapy agent, which could directly be administered via intratumoral injection for tumor therapy.

METHODS

169Yb (T½ = 32 days) was produced by neutron irradiation of enriched (15.2% in 168Yb) Yb2O3 target in a nuclear reactor, radiochemically converted to [169Yb]YbCl3 and used for nanoparticle (NP) synthesis. Intrinsically radiolabeled NP were synthesized by controlled hydrolysis of Yb3+ ions in gum Arabic glycoprotein medium. In vivo SPECT/CT imaging, autoradiography, and biodistribution studies were performed after intratumoral injection of radiolabeled NP in B16F10 tumor bearing C57BL/6 mice. Systematic tumor regression studies and histopathological analyses were performed to demonstrate therapeutic efficacy in the same mice model.

RESULTS

The nanoformulation was a clear solution having high colloidal and radiochemical stability. Uniform distribution and retention of the radiolabeled nanoformulation in the tumor mass were observed via SPECT/CT imaging and autoradiography studies. In a tumor regression study, tumor growth was significantly arrested with different doses of radiolabeled NP compared to the control and the best treatment effect was observed with ~ 27.8 MBq dose. In histopathological analysis, loss of mitotic cells was apparent in tumor tissue of treated groups, whereas no significant damage in kidney, lungs, and liver tissue morphology was observed.

CONCLUSIONS

These results hold promise for nanoscale brachytherapy to become a clinically practical treatment modality for unresectable solid cancers.

Nanocarriers in topical photodynamic therapy

INTRODUCTION

Photodynamic therapy (PDT) has gained significant attention due to its superiority over conventional treatments. In the context of skin cancers and nonmalignant skin diseases, topical application of photosensitizer formulations onto affected skin, followed by illumination, offers distinct advantages. Topical PDT simplifies therapy by providing easy access to the skin, increasing drug concentration within the target area, and confining residual photosensitivity to the treated skin. However, the effectiveness of topical PDT is often hindered by challenges such as limited skin penetration or photosensitizer instability. Additionally, the hypoxic tumor environment poses further limitations. Nanocarriers present a promising solution to address these challenges.

AREAS COVERED

The objective of this review is to comprehensively explore and highlight the role of various nanocarriers in advancing topical PDT for the treatment of skin diseases. The primary focus is to address the challenges associated with conventional topical PDT approaches and demonstrate how nanotechnology-based strategies can overcome these challenges, thereby improving the overall efficiency and efficacy of PDT.

EXPERT OPINION

Nanotechnology has revolutionized the field of PDT, offering innovative tools to combat the unfavorable features of photosensitizers and hurdles in PDT. Nanocarriers enhance skin penetration and stability of photosensitizers, provide controlled drug release, reduce needed dose, increase production of reactive oxygen species, while reducing side effects, thereby improving PDT effectiveness.

In Situ ATR Spectroscopy Study of the Interaction of Acacia senegal Gum with Gold Nanoparticles Films at the Solid-Liquid Interface

The adsorption process of Acacia gum (A. senegal), a complex heteropolysaccharide, was followed by using a spectroscopic method to unravel the relative contribution of the protein moieties and the carbohydrate blocks on the adsorption process. In situ ATR-FTIR was used to investigate the kinetics and conformational changes associated with the adsorption of A. senegal gum on gold nanoparticle films (Au-NPs) at different pHs. The results of this thorough study highlighted the adsorption of A. senegal gum through its protein moieties, in particular, AGPs of low molecular weight and high protein content, close to the Au-NPs surface. Isotherm experiments, by gradually increasing the concentration, showed that the gum adsorption was heterogeneous and followed the Freundlich model for the amide part, while the polysaccharide part followed the Langmuir model. In addition, the hydration and structural organization of the gum layer depended on the gum concentration. A. senegal gum adsorbed irreversibly on Au-NPs whatever the pHs, but the adsorbed layer presented a different behavior depending on pH. A more aggregated and less hydrated structure was observed at acidic pH, while a very hydrated and continuous layer was detected at higher pH. The secondary structure analysis through amide III band revealed a change in the gum secondary structure at high pH with the increase in β-turn while random coil decreased.

Molecular weight-dependent antitumor effects of prunes-derived type I arabinogalactan on human and murine triple wild-type melanomas

The regulation of metastasis-related cellular aspects of two structurally similar AGIs from prunes tea infusion, with different molar masses, was studied in vitro against Triple Wild-Type metastatic melanoma (TWM) from murine and human origin. The higher molar mass AGI (AGI-78KDa) induced TWMs cells death and, in murine cell line, it decreased some metastasis-related cellular processes: invasiveness capacity, cell-extracellular matrix interaction, and colonies sizes. The lower molar mass AGI (AGI-12KDa) did not induce cell death but decreased TWMs proliferation rate and, in murine cell line, it decreased cell adhesion and colonies sizes. Both AGIs alter the clonogenic capacity of human cell line. In spite to understand why we saw so many differences between AGIs effects on murine and human cell lines we performed in silico analysis that demonstrated differential gene expression profiles between them. Complementary network topological predictions suggested that AGIs can modulate multiple pathways in a specie-dependent manner, which explain differential results obtained in vitro between cell lines. Our results pointed to therapeutic potential of AGIs from prunes tea against TWMs and showed that molecular weight of AGIs may influence their antitumor effects.

Novel Gold Nanorods@Thiolated Pectin on the Killing of HeLa Cells by Photothermal Ablation

Gold nanorods (AuNRs) have attracted attention in the field of biomedicine, particularly for their potential as photothermal agents capable of killing tumor cells by photothermic ablation. In this study, the synthesis of novel AuNRs stabilized with thiolated pectin (AuNR@SH-PEC) is reported. To achieve this, thiolated pectin (SH-PEC) was obtained by chemically binding cysteamine motifs to the pectin backbone. The success of the reaction was ascertained using FTIR-ATR. Subsequently, the SH-PEC was used to coat and stabilize the surface of AuNRs (AuNR@SH-PEC). In this context, different concentrations of SH-PEC (0.25, 0.50, 1.0, 2.0, 4.0, and 8.0 mg/mL) were added to 0.50 mL of AuNRs suspended in CTAB, aiming to determine the experimental conditions under which AuNR@SH-PEC maintains stability. The results show that SH-PEC effectively replaced the CTAB adsorbed on the surface of AuNRs, enhancing the stability of AuNRs without affecting their optical properties. Additionally, scanning electron and atomic force microscopy confirmed that SH-PEC is adsorbed into the surface of the AuNRs. Importantly, the dimension size (60 × 15 nm) and the aspect ratio (4:1) remained consistent with those of AuNRs stabilized with CTAB. Then, the photothermal properties of gold nanorods were evaluated by irradiating the aqueous suspension of AuNR@SH-PEC with a CW laser (808 nm, 1 W). These results showed that photothermal conversion efficiency is similar to the photothermal conversion observed for AuNR-CTAB. Lastly, the cell viability assays confirmed that the SH-PEC coating enhanced the biocompatibility of AuNR@SH-PEC. Most important, the viability cell assays subjected to laser irradiation in the presence of AuNR@SH-PEC showed a decrease in the cell viability relative to the non-irradiated cells. These results suggest that AuNRs stabilized with thiolated pectin can potentially be exploited in the implementation of photothermal therapy.

Green Synthesis of Mesquite-Gum-Stabilized Gold Nanoparticles for Biomedical Applications: Physicochemical Properties and Biocompatibility Assessment

Using cytotoxic reducing and stabilizing agents in the synthesis of gold nanoparticles (AuNPs) limits their use in biomedical applications. One strategy to overcome this problem is using "green" synthesis methodologies using polysaccharides. In the present study, we propose a green methodology for synthetizing AuNPs with mesquite gum (MG) as a reducing agent and steric stabilizer in Gold(III) chloride trihydrate aqueous solutions to obtain biocompatible nanoparticles that can be used for biomedical applications. Through this method, AuNPs can be produced without using elevated temperatures or pressures. For synthetizing gold nanoparticles coated with mesquite gum (AuNPs@MG), Gold(III) chloride trihydrate was used as a precursor, and mesquite gum was used as a stabilizing and reducing agent. The AuNPs obtained were characterized using UV-Vis spectroscopy, dynamic light scattering, transmission electron microscopy, scanning transmission electron microscopy, and FT-IR spectroscopy. The stability in biological media (phosphate buffer solution), cytotoxicity (MTT assay, hematoxylin, and eosin staining), and hemocompatibility (Hemolysis assay) were measured at different concentrations and exposure times. The results showed the successful synthesis of AuNPs@MG with sizes ranging from 3 to 30 nm and a zeta potential of -31 mV. The AuNPs@MG showed good colloidal stability in PBS (pH 7.4) for up to 24 h. Finally, cytotoxicity assays showed no changes in cell metabolism or cell morphology. These results suggest that these gold nanoparticles have potential biomedical applications because of their low cytotoxicity and hemotoxicity and improved stability at a physiological pH.

Gum Arabic-mediated liquid exfoliation of transition metal dichalcogenides as photothermic anti-breast cancer candidates

Transition metal dichalcogenides (TMDs) have gained considerable attention for a broad range of applications, including cancer therapy. Production of TMD nanosheets using liquid exfoliation provides an inexpensive and facile route to achieve high yields. In this study, we developed TMD nanosheets using gum arabic as an exfoliating and stabilizing agent. Different types of TMDs, including MoS₂, WS₂, MoSe₂, and WSe₂ nanosheets, were produced using gum arabic and were characterized physicochemically. The developed gum arabic TMD nanosheets exhibited a remarkable photothermal absorption capacity in the near-infrared (NIR) region (808 nm and 1 W⋅cm^-2). The drug doxorubicin was loaded on the gum arabic-MoSe₂ nanosheets (Dox-G-MoSe₂), and the anticancer activity was evaluated using MDA-MB-231 cells and a water-soluble tetrazolium salt (WST-1) assay, live and dead cell assays, and flow cytometry. Dox-G-MoSe₂ significantly inhibited MDA-MB-231 cancer cell proliferation under the illumination ofan NIR laser at 808 nm. These results indicate that Dox-G-MoSe₂ is a potentially valuable biomaterial for breast cancer therapy.

Complex mixtures of pesticides and metabolites modulate the malignant phenotype of murine melanoma B16-F1 cells

Pesticides use increased worldwide with a record in Brazil. Although several works addressed the effects of pesticides on living organisms, only a few considered their mixture, and even fewer tried to unravel their role in tumoral progression. Due to the relevance of cancer, in the present study, the effects of the mixture of pesticides widely used in Brazil (Glyphosate, 2,4-dichlorophenoxyacetic acid, Mancozeb, Atrazine, Acephate, and Paraquat) and their main metabolites (Aminomethylphosphonic Acid, 2,4-diclorophenol, Ethylenethiourea, Desethylatrazine, Methamidophos, and Paraquat) were investigated on the malignancy phenotype of murine melanoma B16-F1 cells after acute (24 h) and chronic (15 days) exposures. The tested concentrations were based on the Acceptable Daily Intake (ADI) value established by Brazilian legislation. The set of results showed that these chemicals modulate important parameters of tumor progression, affecting the expression of genes related to tumor aggressiveness (Mmp14 and Cd44) and multidrug resistance (Abcb1, Abcc1, and Abcc4), as well as tissue inhibitors of metalloproteinases (Timp1, Timp2, and Timp3). These findings revealed an absence of cytotoxicity but showed modulation of migration, invasion, and colonization capacity of B16-F1 cells. Together, the results point to some negative ways that exposure to pesticides can affect the progression of melanoma and raise a concern related to the increasing trend in pesticide use in Brazil, as the country is one of the major world food suppliers.

Impact of Hydrophobic and Electrostatic Forces on the Adsorption of Acacia Gum on Oxide Surfaces Revealed by QCM-D

The adsorption of Acacia gum from two plant exudates, A. senegal and A. seyal, at the solid-liquid interface on oxide surfaces was studied using a quartz crystal microbalance with dissipation monitoring (QCM-D). The impact of the hydrophobic and electrostatic forces on the adsorption capacity was investigated by different surface, hydrophobicity, and charge properties, and by varying the ionic strength or the pH. The results highlight that hydrophobic forces have higher impacts than electrostatic forces on the Acacia gum adsorption on the oxide surface. The Acacia gum adsorption capacity is higher on hydrophobic surfaces compared to hydrophilic ones and presents a higher stability with negatively charged surfaces. The structural configuration and charge of Acacia gum in the first part of the adsorption process are important parameters. Acacia gum displays an extraordinary ability to adapt to surface properties through rearrangements, conformational changes, and/or dehydration processes in order to reach the steadiest state on the solid surface. Rheological analysis from QCM-D data shows that the A. senegal layers present a viscous behavior on the hydrophilic surface and a viscoelastic behavior on more hydrophobic ones. On the contrary, A. seyal layers show elastic behavior on all surfaces according to the Voigt model or a viscous behavior on the hydrophobic surface when considering the power-law model.

Carbohydrate polymer-based nanocomposites for breast cancer treatment

Breast cancer is known as the most common invasive malignancy in women with the highest mortality rate worldwide. This concerning disease may be presented in situ (relatively easier treatment) or be invasive, especially invasive ductal carcinoma which is highly worrisome nowadays. Among several strategies used in breast cancer treatment, nanotechnology-based targeted therapy is currently being investigated, as it depicts advanced technological features able of preventing drugs' side effects on normal cells while effectively acting on tumor cells. In this context, carbohydrate polymer-based nanocomposites have gained particular interest among the biomedical community for breast cancer therapy applications due to their advantage features, including abundance in nature, biocompatibility, straightforward fabrication methods, and good physicochemical properties. In this review, the physicochemical properties and biological activities of carbohydrate polymers and their derivate nanocomposites were discussed. Then, various methods for the fabrication of carbohydrate polymer-based nanocomposites as well as their application in breast cancer therapy and future perspectives were discussed.

Temperature influence on NiFeMo nanoparticles magnetic properties and their viability in biomedical applications

NiFeMo alloy nanoparticles were synthesized by co-precipitation in the presence of organic additives. Nanoparticles thermal evolution shows that there is a significant increase in the average size (from 28 to 60 nm), consolidating a crystalline structure of the same type as the Ni₃ Fe phase but with lattice parameter a = 0.362 nm. Measurements of magnetic properties follow this morphological and structural evolution increasing saturation magnetization (Ms) by 578% and reducing remanence magnetization (Mr) by 29%. Cell viability assays on as-synthesized revealed that nanoparticles (NPs) are not cytotoxic up to a concentration of 0.4 μg/mL for both non-tumorigenic (fibroblasts and macrophages) and tumor cells (melanoma).

Advancements in nanoparticle-based treatment approaches for skin cancer therapy

Skin cancer has emerged as the fifth most commonly reported cancer in the world, causing a burden on global health and the economy. The enormously rising environmental changes, industrialization, and genetic modification have further exacerbated skin cancer statistics. Current treatment modalities such as surgery, radiotherapy, conventional chemotherapy, targeted therapy, and immunotherapy are facing several issues related to cost, toxicity, and bioavailability thereby leading to declined anti-skin cancer therapeutic efficacy and poor patient compliance. In the context of overcoming this limitation, several nanotechnological advancements have been witnessed so far. Among various nanomaterials, nanoparticles have endowed exorbitant advantages by acting as both therapeutic agents and drug carriers for the remarkable treatment of skin cancer. The small size and large surface area to volume ratio of nanoparticles escalate the skin tumor uptake through their leaky vasculature resulting in enhanced therapeutic efficacy. In this context, the present review provides up to date information about different types and pathology of skin cancer, followed by their current treatment modalities and associated drawbacks. Furthermore, it meticulously discusses the role of numerous inorganic, polymer, and lipid-based nanoparticles in skin cancer therapy with subsequent descriptions of their patents and clinical trials.