An insight into synthesis and antitumor activity of citrate and gallate stabilizing gold nanospheres

Targeted synthesis of gold nanorods and characterization of their tailored surface properties using optical and X-ray spectroscopy

In recent years, nanophotonics have had a transformative impact on harnessing energy, directing chemical reactions, and enabling novel molecular dynamics for thermodynamically intensive applications. Plasmonic nanoparticles have emerged as a tool for confining light on nanometer-length scales where regions of intense electromagnetic fields can be precisely tuned for controlled surface chemistry. We demonstrate a precision pH-driven synthesis of gold nanorods with optical resonance properties widely tunable across the near-infrared spectrum. Through controlled electrostatic interactions, we can perform selective adsorbate molecule attachment and monitor the surface transitions through spectroscopic techniques that include ground-state absorption spectrophotometry, two-dimensional X-ray absorption near-edge spectroscopy, Fourier-transform infrared spectroscopy, and surface-enhanced Raman spectroscopy. We elucidate the electronic, structural, and chemical factors that contribute to plasmon-molecule dynamics at the nanoscale with broad implications for the fields of energy, photonics, and bio-inspired materials.

Tau- and α-synuclein-targeted gold nanoparticles: applications, opportunities, and future outlooks in the diagnosis and therapy of neurodegenerative diseases

The use of nanomaterials in medicine offers multiple opportunities to address neurodegenerative disorders such as Alzheimer's and Parkinson's disease. These diseases are a significant burden for society and the health system, affecting millions of people worldwide without sensitive and selective diagnostic methodologies or effective treatments to stop their progression. In this sense, the use of gold nanoparticles is a promising tool due to their unique properties at the nanometric level. They can be functionalized with specific molecules to selectively target pathological proteins such as Tau and α-synuclein for Alzheimer's and Parkinson's disease, respectively. Additionally, these proteins are used as diagnostic biomarkers, wherein gold nanoparticles play a key role in enhancing their signal, even at the low concentrations present in biological samples such as blood or cerebrospinal fluid, thus enabling an early and accurate diagnosis. On the other hand, gold nanoparticles act as drug delivery platforms, bringing therapeutic agents directly into the brain, improving treatment efficiency and precision, and reducing side effects in healthy tissues. However, despite the exciting potential of gold nanoparticles, it is crucial to address the challenges and issues associated with their use in the medical field before they can be widely applied in clinical settings. It is critical to ensure the safety and biocompatibility of these nanomaterials in the context of the central nervous system. Therefore, rigorous preclinical and clinical studies are needed to assess the efficacy and feasibility of these strategies in patients. Since there is scarce and sometimes contradictory literature about their use in this context, the main aim of this review is to discuss and analyze the current state-of-the-art of gold nanoparticles in relation to delivery, diagnosis, and therapy for Alzheimer's and Parkinson's disease, as well as recent research about their use in preclinical, clinical, and emerging research areas.

Cervical cancer: Novel treatment strategies offer renewed optimism

Cervical cancer poses a significant global public health issue, primarily affecting women, and stands as one of the four most prevalent cancers affecting woman globally, which includes breast cancer, colorectal cancer, lung cancer and cervical cancer. Almost every instance of cervical cancer is associated with infections caused by the human papillomavirus (HPV). Prevention of this disease hinges on screening and immunization of the patients, yet disparities in cervical cancer occurrence exist between developed and developing nations. Multiple factors contribute to cervical cancer, including sexually transmitted diseases (STDs), reproductive and hormonal influences, genetics, and host-related factors. Preventive programs, lifestyle improvements, smoking cessation, and prompt precancerous lesion treatment can reduce the occurrence of cervical cancer. The persistency and recurrence of the cases are inherited even after the innovative treatments available for cervical cancer. For patient's ineligible for curative surgery or radiotherapy, palliative chemotherapy remains the standard treatment. Novel treatment strategies are emerging to combat the limited effectiveness of chemotherapy. Nanocarriers offer the promise of concurrent chemotherapeutic drug delivery as a beacon of hope in cervical cancer research. The primary aim of this review study is to contribute to a thorough understanding of cervical cancer, fostering awareness and informed decision-making and exploring novel treatment methods such as nanocarriers for the treatment of cervical cancer. This manuscript delves into cutting-edge approaches, exploring the potential of nanocarriers and other innovative treatments. Our study underscores the critical need for global awareness, early intervention, and enhanced treatment options. Novel strategies, such as nanocarriers, offer renewed optimism in the battle against cervical cancer. This research provides compelling evidence for the investigation of these novel therapeutic approaches within the medical field. Cervical cancer remains a formidable adversary, but with ongoing advancements and unwavering commitment, we move closer to a future where it is a preventable and treatable disease, even in the most underserved regions.

Design of flavonol-loaded cationic gold nanoparticles with enhanced antioxidant and antibacterial activities and their interaction with proteins

In this work, four structurally similar flavonols (galangin, kaempferol, quercetin and myricetin) were coated on the surface of (11-mercaptoundecyl)-N,N,N-trimethylammonium bromide (MUTAB)‑gold nanoparticles (AuNPs) by two-step phase transfer and self-assembly, and the cationic MUTAB- AuNPs coated with flavonols (flavonol-MUTAB-AuNPs) were designed. Free radical scavenging and antibacterial experiments show that flavonol-MUTAB-AuNPs greatly improve the scavenging effect on DPPH, hydroxyl and superoxide anion radicals, and significantly enhance the inhibition effect on Staphylococcus aureus and Escherichia coli compared with flavonols and AuNPs. Then γ-globulin, fibrinogen, trypsin and pepsin were selected as representative proteins and their interaction with flavonol-MUTAB-AuNPs were investigated by various spectroscopic techniques. The fluorescence quenching mechanism of these four proteins by flavonol-MUTAB-AuNPs is static quenching. The binding constants Ka between them are in the range of 103 to 106. The interaction between them is endothermic, entropy-driven spontaneous process, and the main non-covalent force is the hydrophobic interaction. The effect of flavonol-MUTAB-AuNPs on the structure of the four proteins were investigated using UV-vis absorption spectra, synchronous fluorescence spectra and circular dichroism spectra. These results offer important insights into the essence of the interaction between flavonol-MUTAB-AuNPs and γ-globulin/fibrinogen/trypsin/pepsin. They will contribute to the development of safe and effective flavonol-MUTAB-AuNPs in biomedical fields.

How gallic acid regulates molecular signaling: role in cancer drug resistance

Cancer is one of the deadliest and most heterogeneous diseases. Cancers often develop drug resistance, which can lead to treatment failure or recurrence. Accordingly, anticancer compounds are essential for chemotherapy-resistant cancer cells. Phenolic compounds are of interest in the development of cancer drugs due to their medicinal properties and ability to target different molecular pathways. Gallic acid (GA), as one of the main components of phenol, which is abundantly present in plant compounds such as walnut, sumac, grapes, tea leaves, oak bark, and other plant compounds, has antitumor properties. GA can prevent cancer progression, cell invasion, and metastasis by targeting molecular pathways and is an effective complement to chemotherapy drugs and combating multidrug resistance (MDR). In this review, we discuss various mechanisms related to cancer, the therapeutic potential of GA, the antitumor properties of GA in various cancers, and the targeted delivery of GA with nanocarriers.

Simulation of gold nanoparticle movement through normal and cancer cell membranes

Gold nanoparticles (Au-NPs) have been used for a long time to target cancer cells. Different modalities have been suggested to utilize Au-NPs in cancer patients. We construct both normal and cancer cell membranes to simulate the Au-NP entry to understand better how it can penetrate the cancer cell membrane. We use molecular dynamics simulation (MDS) on both normal and cancer cell membrane models for 150 ns. At the same time, we prepared the Au-NP of spherical shape (16 nm radius) capped with citrate using MDS for 100 ns. Finally, we added the Au-NP close to the membranes and moved it using 1000 kJ mol-1 nm-1 force constant during the 7.7 ns MDS run. We analyzed the membranes in the presence and absence of the Au-NP and compared normal and cancer membranes. The results show that normal cell membranes have higher stability than cancer membranes. Additionally, Au-NP forms pore in the membranes that facilitate water and ions entry during the movement inside the lipid bilayer region. These pores are responsible for the enhanced response of Au-NP-loaded chemotherapeutic agents in cancer treatment.