The ligand exchange of citrates to thioabiraterone on gold nanoparticles for prostate cancer therapy

Harnessing the power of gold: advancements in anticancer gold complexes and their functionalized nanoparticles

Cancer poses a formidable challenge, necessitating improved treatment strategies. Metal-based drugs and nanotechnology offer new hope in this battle. Versatile gold complexes and functionalized gold nanoparticles exhibit unique properties like biologically inert behaviour, outstanding light absorption, and heat-conversion abilities. These nanoparticles can be finely tuned for drug delivery, enabling precise and targeted cancer therapy. Their exceptional drug-loading capacity and low toxicity, stemming from excellent stability, biocompatibility, and customizable shapes, make them a promising option for enhancing cancer treatment outcomes and improving diagnostic imaging. Leveraging these attributes, researchers can design more effective and targeted cancer therapeutics. The potential of functionalized gold nanoparticles to advance cancer treatment and diagnostics holds a promising avenue for further exploration and development in the fight against cancer. This review article delves into the finely tuned attributes of functionalized gold nanoparticles, unveiling their potential for application in drug delivery for precise and targeted cancer therapy.

Bovine Serum Albumin - Hydroxyapatite Nanoflowers as Potential Local Drug Delivery System of Ciprofloxacin

Introduction

Hybrid nanoflowers are structures consisting of organic (enzymes, proteins, nucleic acids) and inorganic components (mostly metal phosphates) with a flower-like hierarchical structure. Novel hybrid nanoflowers based on bovine serum albumin (BSA) and hydroxyapatite (HA) were obtained and characterized. Study on BSA-HA nanoflowers as potential drug delivery system is reported for the first time.

Methods

Embedding ciprofloxacin in the structure of hybrid nanoflowers was confirmed by ATR-FTIR and thermogravimetric analysis. The inorganic phase of the nanoflowers was determined by X-ray diffraction. UV‒Vis spectroscopy was used to evaluate the release profiles of ciprofloxacin from nanoflowers in buffer solutions at pH 7.4 and 5. The agar disk diffusion method was used to study the antibacterial activity of the synthesized nanoflowers against Staphylococcus aureus and Pseudomonas aeruginosa.

Results

Bovine serum albumin - hydroxyapatite nanoflowers were obtained with diameters of ca. 1-2 µm. The kinetics of ciprofloxacin release from nanoflowers were described by the Korsmeyer-Peppas model. The antibacterial activity of the synthesized nanoflowers was demonstrated against S. aureus and P. aeruginosa, two main pathogens found in osteomyelitis.

Conclusion

The formulated nanoflowers may act as an efficient local antibiotic delivery system. Due to the use of nonhazardous, biodegradable components and benign synthesis, hybrid nanoflowers are very promising drug delivery systems that could be applied in the treatment of skeletal system infections.

Computational Modeling of Gold Nanoparticle Interacting with Molecules of Pharmaceutical Interest in Water

We derived a theory of biomolecule binding to the surface of Aun clusters and of the Au plane based on the hard soft acid base (HSAB) principle and the free electron metallic surface model. With the use of quantum mechanical calculations, the chemical potential (μ) and the chemical hardness (η) of the biomolecules are estimated. The effect of the gold is introduced via the empirical value of the gold chemical potential (-5.77 eV) as well as by using the expression (modified here) for the chemical hardness (η). The effect of an aqueous environment is introduced by means of the ligand molecular geometry influenced by the PCM field. This theory allows for a fast and low-cost estimation of binding biomolecules to the AuNPs surface. The predicted binding of thiolated genistein and abiraterone to the gold surface is about 20 kcal/mol. The model of the exchange reaction between these biomolecules and citrates on the Au surface corresponds well with the experimental observations for thiolated abiraterone. Moreover, using a model of the place exchange of linear mercaptohydrocarbons on 12-mercaptododecane acid methyl ester bound to the Au surface, the present results reflect the known relation between exchange energy and the size of the reagents.

Current applications of nanomaterials in urinary system tumors

The development of nanotechnology and nanomaterials has provided insights into the treatment of urinary system tumors. Nanoparticles can be used as sensitizers or carriers to transport drugs. Some nanoparticles have intrinsic therapeutic effects on tumor cells. Poor patient prognosis and highly drug-resistant malignant urinary tumors are worrisome to clinicians. The application of nanomaterials and the associated technology against urinary system tumors offers the possibility of improving treatment. At present, many achievements have been made in the application of nanomaterials against urinary system tumors. This review summarizes the latest research on nanomaterials in the diagnosis and treatment of urinary system tumors and provides novel ideas for future research on nanotechnologies in this field.

The Applications of Gold Nanoparticles in the Diagnosis and Treatment of Gastrointestinal Cancer

In recent years, the morbidity and mortality of gastrointestinal cancer have remained high in China. Due to the deep location of the gastrointestinal organs, such as gastric cancer, the early symptoms of cancer are not obvious. It is generally discovered at an advanced stage with distant metastasis and lymph node infiltration, making it difficult to cure. Therefore, there is a significant need for novel technologies that can effectively diagnose and treat gastrointestinal cancer, ultimately reducing its mortality. Gold nanoparticles (GNPs), a type of nanocarrier with unique optical properties and remarkable biocompatibility, have the potential to influence the fate of cancer by delivering drugs, nucleic acids to cancer cells and tissues. As a safe and reliable visualization agent, GNPs can track drugs and accurately indicate the location and boundaries of cancer, opening up new possibilities for cancer treatment. In addition, GNPs have been used in photodynamic therapy to deliver photosensitizers, as well as in combination with photothermal therapy. Therefore, GNPs can be used as a safe and effective nanomaterial in the treatment and diagnosis of gastrointestinal cancer.

New Supramolecular Drug Carriers: The Study of Organogel Conjugated Gold Nanoparticles

An aqueous solution of sodium citrate stabilized gold nanoparticles (AuNP) in the presence of N-lauroyl-L-alanine (C12ALA) forms a stable gel. The structure of the gel and the distribution profile of AuNP in it were analyzed. Will nanoparticles separated from each other with sodium citrate behave in the same way in solution and trapped in the gel matrix? Will the spatial limitation of solvent molecules aggregate nanoparticles and destroy their homogeneity? These questions are very important from the point of view of the use of gold nanoparticles, trapped in the gel structure as carriers of drugs in the slow-release process. The lack of homogeneity of this distribution will have a major impact on the rate of release of the appropriate amount of therapeutic drug from the matrix. In this work, we attempt to answer these questions. The performed biological assays revealed that both C12ALA and C12ALA-AuNP show an excellent level of biological neutrality. They might be used as a transporting medium for a drug delivery without affecting the drug's activity.

Dual anticancer drug-loaded self-assembled nanomaterials delivery system for the treatment of prostate cancer

This study explains the engineering of polylactide-polyethylene succinate glycol nanomaterials (NMs), to achieve superior anticancer effectiveness in prostate cancer therapy as a carriers of crizotinib (CZT) and marizomib (MAR). We have shown that the block polymers and hydrophobic drugs can be self-assembled to construct a highly stable nanocarrier with highly adaptable to support the use of cancer medicines. The Drug Release analysis revealed that the interference in the hydrophobic cores of micelles was a continuous release series. In both PC3pip and LNCAP prostate cancer cells, CZT@MAR NMs demonstrated noticeable cytotoxic effects in a dose-responsive method. In addition, morphology analysis and the AO-EB and nuclear staining assay showed a higher effectiveness in prostate cancer for nanomaterials. The polymeric nanomaterials displayed a prominent existence in the cytoplasmic cell regions, which shows a characteristic cell uptake by endocytosis. A significant apoptosis, compared to free CZT@MAR apoptosis, was found in the FITC-Annexin V/PI staining-based apoptosis analysis. In this juncture, the alternative drug delivery mechanism for the improvement of CZT@MAR chemotherapeutic effectiveness in prostate cancer chemotherapy modification PLA nanoparticles.

Factors Influencing the Surface Functionalization of Citrate Stabilized Gold Nanoparticles with Cysteamine, 3-Mercaptopropionic Acid or l-Selenocystine for Sensor Applications

Thiols and selenides bind to the surface of gold nanoparticles (AuNPs) and thus provide suitable platforms for the fabrication of sensors. However, the co-existence of adsorbed citrate on the surface of the nanoparticles can influence their functionalization behavior and potentially their sensing performance measured by the extent of particle aggregation. In this study, the functionalization of purchased (7.3 ± 1.2 nm) and in-house prepared AuNPs (13.8 ± 1.2 nm), under the same experimental conditions with either cysteamine (Cys), 3-mercaptopropionic acid (3-MPA), or l-selenocystine (SeCyst) was investigated. 1H-NMR measurements showed distinct citrate signatures on the in-house synthesized citrate-stabilized AuNPs, while no citrate signals were detected on the purchased AuNPs other than evidence of the presence of α-ketoglutaric acid. Carboxylate-containing species attributed to either citrate or α-ketoglutaric acid were identified in all functionalized AuNPs. ATR-FTIR spectroscopy confirmed the functionalization of AuNPs with Cys and 3-MPA, and energy dispersive X-ray (EDX) spectroscopy measurements suggested the formation of SeCyst functionalized AuNPs. Co-adsorption rather than displacement by the functionalizing agents and carboxylate-containing molecules was indicated, which for Cys and SeCyst functionalized AuNPs was also the aggregation limiting factor. In contrast, the behavior of 3-MPA functionalized AuNPs could be attributed to electrostatic repulsions between the functionalized groups.

Synthesis of Thiol Derivatives of Biological Active Compounds for Nanotechnology Application

An efficient method of thiol group introduction to the structure of common natural products and synthetic active compounds with recognized biological efficacy such genistein (1), 5,11-dimethyl-5H-indolo[2,3-b]quinolin (2), capecitabine (3), diosgenin (4), tigogenin (5), flumethasone (6), fluticasone propionate (7), ursolic acid methyl ester (8), and β-sitosterol (9) was developed. In most cases, the desired compounds were obtained easily via two-step processes involving esterification reaction employing S-trityl protected thioacetic acid and the corresponding hydoxy-derivative, followed by removal of the trityl-protecting group to obtain the final compounds. The results of our preliminary experiments forced us to change the strategy in the case of genistein (1), and the derivatization of diosgenin (4), tigogenin (5), and capecitabine (3) resulted in obtaining different compounds from those designed. Nevertheless, in all above cases we were able to obtain thiol-containing derivatives of selected biological active compounds. Moreover, a modelling study for the two-step thiolation of genistein and some of its derivatives was accomplished using the density functional theory (B3LP). A hypothesis on a possible reason for the unsuccessful deprotection of the thiolated genistein is also presented based on the semiempirical (PM7) calculations. The developed methodology gives access to new sulphur derivatives, which might find a potential therapeutic benefit.