Gold nanoparticle platforms as drug and biomacromolecule delivery systems

Preadsorbed Chymotrypsin Modulated the Composition of Protein Corona and Immunological Response

It is well-known that proteins after administration into biological environments adsorb on the surface of nanoparticles (NPs). The biological identity could be determined by protein corona, but whether and how the preadsorbed molecules impact the composition of the corona and immunological response have rarely been reported. Here, the effects of preadsorbed chymotrypsin (Chy) on forming protein corona and subsequent immunological response are reported. We find that preadsorbed Chy on the surface of AuNPs results in a protein corona with enriched immunoglobulins and reduced human serum albumin protein, which further affect the polarization of macrophages into specific phenotypes. Our study suggests that the protein surrounding the nanoparticles could affect the protein corona and immunological response, which may direct the preparation of multifunctional nanomedicine for future studies.

A review on gold nanoparticles as an innovative therapeutic cue in bone tissue engineering: Prospects and future clinical applications

Bone damage is a complex orthopedic problem primarily caused by trauma, cancer, or bacterial infection of bone tissue. Clinical care management for bone damage remains a significant clinical challenge and there is a growing need for more advanced bone therapy options. Nanotechnology has been widely explored in the field of orthopedic therapy for the treatment of a severe bone disease. Among nanomaterials, gold nanoparticles (GNPs) along with other biomaterials are emerging as a new paradigm for treatment with excellent potential for bone tissue engineering and regenerative medicine applications. In recent years, a great deal of research has focused on demonstrating the potential for GNPs to provide for enhancement of osteogenesis, reduction of osteoclastogenesis/osteomyelitis, and treatment of bone cancer. This review details the latest understandings in regards to GNPs based therapeutic systems, mechanisms, and the applications of GNPs against various bone disorders. The present review aims to summarize i) the mechanisms of GNPs in bone tissue remodeling, ii) preparation methods of GNPs, and iii) functionalization of GNPs and its decoration on biomaterials as a delivery vehicle in a specific bone tissue engineering for future clinical application.

Nanoformulation of dasatinib cannot overcome therapy resistance of pancreatic cancer cells with low LYN kinase expression

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is one of the most difficult to treat tumors. The Src (sarcoma) inhibitor dasatinib (DASA) has shown promising efficacy in preclinical studies of PDAC. However, clinical confirmation could not be achieved. Overall, our aim was to deliver arguments for the possible reinitiating clinical testing of this compound in a biomarker-stratifying therapy trial for PDAC patients. We tested if the nanofunctionalization of DASA can increase the drug efficacy and whether certain Src members can function as clinical predictive biomarkers.

METHODS

Methods include manufacturing of poly(vinyl alcohol) stabilized gold nanoparticles and their drug loading, dynamic light scattering, transmission electron microscopy, thermogravimetric analysis, Zeta potential measurement, sterile human cell culture, cell growth quantification, accessing and evaluating transcriptome and clinical data from molecular tumor dataset TCGA, as well as various statistical analyses.

RESULTS

We generated homo-dispersed nanofunctionalized DASA as an AuNP@PVA-DASA conjugate. The composite did not enhance the anti-growth effect of DASA on PDAC cell lines. The cell model with high LYN expression showed the strongest response to the therapy. We confirm deregulated Src kinetome activity as a prevalent feature of PDAC by revealing mRNA levels associated with higher malignancy grade of tumors. BLK (B lymphocyte kinase) expression predicts shorter overall survival of diabetic PDAC patients.

CONCLUSIONS

Nanofunctionalization of DASA needs further improvement to overcome the therapy resistance of PDAC. LYN mRNA is augmented in tumors with higher malignancy and can serve as a predictive biomarker for the therapy resistance of PDAC cells against DASA. Studying the biological roles of BLK might help to identify underlying molecular mechanisms associated with PDAC in diabetic patients.

Biomaterial-Based CRISPR/Cas9 Delivery Systems for Tumor Treatment

CRISPR/Cas9 gene editing technology is characterized by high specificity and efficiency, and has been applied to the treatment of human diseases, especially tumors involving multiple genetic modifications. However, the clinical application of CRISPR/Cas9 still faces some major challenges, the most urgent of which is the development of optimized delivery vectors. Biomaterials are currently the best choice for use in CRISPR/Cas9 delivery vectors owing to their tunability, biocompatibility, and efficiency. As research on biomaterial vectors continues to progress, hope for the application of the CRISPR/Cas9 system for clinical oncology therapy builds. In this review, we first detail the CRISPR/Cas9 system and its potential applications in tumor therapy. Then, we introduce the different delivery forms and compare the physical, viral, and non-viral vectors. In addition, we analyze the characteristics of different types of biomaterial vectors. We further review recent research progress in the use of biomaterials as vectors for CRISPR/Cas9 delivery to treat specific tumors. Finally, we summarize the shortcomings and prospects of biomaterial-based CRISPR/Cas9 delivery systems.

Near-infrared responsive gold nanorods for highly sensitive colorimetric and photothermal lateral flow immuno-detection of SARS-CoV-2

The highly infectious characteristics of coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), highlight the necessity of sensitive and rapid nucleocapsid (N) protein-based antigen testing for early triage and epidemic management. In this study, a colorimetric and photothermal dual-mode lateral flow immunoassay (LFIA) platform for the rapid and sensitive detection of the SARS-CoV-2 N protein was developed based on gold nanorods (GNRs), which possessed tunable local surface plasma resonance (LSPR) absorption peaks from UV-visible to near-infrared (NIR). The LSPR peak was adjusted to match the NIR emission laser 808 nm by controlling the length-to-diameter ratio, which could maximize the photothermal conversion efficiency and achieve photothermal detection signal amplification. Qualitative detection of SARS-CoV-2 N protein was achieved by observing the strip color, and the limit of detection was 2 ng mL-1, while that for photothermal detection was 0.096 ng mL-1. Artificial saliva samples spiked with the N protein were analyzed with the recoveries ranging from 84.38% to 107.72%. The intra-assay and inter-assay coefficients of variation were 6.76% and 10.39%, respectively. We further evaluated the reliability of this platform by detecting 40 clinical samples collected from nasal swabs, and the results matched well with that of nucleic acid detection (87.5%). This method shows great promise in early disease diagnosis and screening.

The role of radiolabeling in BNCT tracers for enhanced dosimetry and treatment planning

Positron emission tomography (PET) and single photon emission computed tomography (SPECT) are potent technologies for non-invasive imaging of pharmacological and biochemical processes in both preclinical and advanced clinical research settings. In the field of radiation therapy, boron neutron capture therapy (BNCT) stands out because it harnesses biological mechanisms to precisely target tumor cells while preserving the neighboring healthy tissues. To achieve the most favorable therapeutic outcomes, the delivery of boron-enriched tracers to tumors must be selective and efficient, with a substantial concentration of boron atoms meticulously arranged in and around the tumor cells. Although several BNCT tracers have been developed to facilitate the targeted and efficient delivery of boron to tumors, only a few have been labeled with PET or SPECT radionuclides. Such radiolabeling enables comprehensive in vivo examination, encompassing crucial aspects such as pharmacodynamics, pharmacokinetics, tumor selectivity, and accumulation and retention of the tracer within the tumor. This review provides a comprehensive summary of the essential aspects of BNCT tracers, focusing on their radiolabeling with PET or SPECT radioisotopes. This leads to more effective and targeted treatment approaches which ultimately enhance the quality of patient care with respect to cancer treatment.

Delivery of gold nanoparticle-conjugated M2e influenza vaccine in mice using coated microneedles

As a prospective influenza vaccination platform, a microneedle patch offers advantages such as self-administration and reduction of needle-phobia-associated vaccination avoidance. In an effort to design a broadly protective influenza vaccine we have previously developed a vaccine formulation containing the highly conserved ectodomain sequence of the M2 influenza protein (M2e) attached to the surface of gold nanoparticles (AuNPs) with CpG as a soluble adjuvant (AuNP-M2e + sCpG). Our previous studies have used the intranasal route for vaccination and demonstrated broad protection from this vaccine. Here we asked the question whether the same formulation can be effective when administered to mice using microneedles. We demonstrate that the microneedles can be coated with AuNP-M2e + sCpG formulation, and the AuNPs from the coating can be readily resuspended without aggregation. The AuNPs were delivered with high efficiency into murine skin, and the AuNPs cleared the skin within 12 h of microneedle treatment. After vaccination, strong M2e-specific humoral and cellular responses were stimulated, and the vaccinated mice were 100% protected following a lethal challenge with influenza A/PR/8/34 (H1N1).

Exploring the potential of approved drugs for triple-negative breast cancer treatment by targeting casein kinase 2: Insights from computational studies

Triple-negative breast cancer (TNBC) is an aggressive malignancy that requires effective targeted drug therapy. In this study, we employed in silico methods to evaluate the efficacy of seven approved drugs against human ck2 alpha kinase, a significant modulator of TNBC metastasis and invasiveness. Molecular docking revealed that the co-crystallized reference inhibitor 108600 achieved a docking score of (-7.390 kcal/mol). Notably, among the seven approved drugs tested, sunitinib, bazedoxifene, and etravirine exhibited superior docking scores compared to the reference inhibitor. Specifically, their respective docking scores were -10.401, -7.937, and -7.743 kcal/mol. Further analysis using MM/GBSA demonstrated that these three top-ranked drugs possessed better binding energies than the reference ligand. Subsequent molecular dynamics simulations identified etravirine, an FDA-approved antiviral drug, as the only repurposed drug that demonstrated a stable and reliable binding mode with the human ck2 alpha protein, based on various analysis measures including RMSD, RMSF, and radius of gyration. Principal component analysis indicated that etravirine exhibited comparable stability of motion as a complex with human ck2 alpha protein, similar to the co-crystallized inhibitor. Additionally, Density functional theory (DFT) calculations were performed on a complex of etravirine and a representative gold atom positioned at different sites relative to the heteroatoms of etravirine. The results of the DFT calculations revealed low-energy complexes that could potentially serve as guides for experimental trials involving gold nanocarriers of etravirine, enhancing its delivery to malignant cells and introducing a new drug delivery route. Based on the results obtained in this research study, etravirine shows promise as a potential antitumor agent targeting TNBC, warranting further investigation through experimental and clinical assessments.

CRISPR-Mediated Base Editing: Promises and Challenges for a Viable Oncotherapy Strategy

Base editing technology, developed from the CRISPR/Cas9 system, is able to efficiently implement single-base substitutions at specific DNA or RNA sites without generating double-strand breaks with precision and efficiency. Point mutations account for 58% of disease-causing genetic mutations in humans, and single nucleotide variants are an important cause of tumorigenesis, and the advent of base editors offers new hope for the study or treatment of such diseases. Although it has some limitations, base editors have been continuously improved in terms of editing efficiency, specificity, and product purity since their development. In this review, we examine the main base editing technologies and discuss their applications and prospects in tumor research and therapy, as well as elaborate on their mode of delivery.

Nuclear Delivery of Nanoparticle-Based Drug Delivery Systems by Nuclear Localization Signals

Nanomedicine 2.0 refers to the next generation of nanotechnology-based medical therapies and diagnostic tools. This field focuses on the development of more sophisticated and precise nanoparticles (NPs) for targeted drug delivery, imaging, and sensing. It has been established that the nuclear delivery of NP-loaded drugs can increase their therapeutic efficacy. To effectively direct the NPs to the nucleus, the attachment of nuclear localization signals (NLSs) to NPs has been employed in many applications. In this review, we will provide an overview of the structure of nuclear pore complexes (NPCs) and the classic nuclear import mechanism. Additionally, we will explore various nanoparticles, including their synthesis, functionalization, drug loading and release mechanisms, nuclear targeting strategies, and potential applications. Finally, we will highlight the challenges associated with developing nucleus-targeted nanoparticle-based drug delivery systems (NDDSs) and provide insights into the future of NDDSs.

Enhanced resonance energy transfer in gold nanoparticles bifunctionalized by tryptophan and riboflavin and its application in fluorescence bioimaging

Gold nanoparticles were functionalized by amino acid tryptophan and vitamin riboflavin - a resonance energy transfer (RET) pair of biomolecules. The presence of the gold nanoparticles resulted in 65% increase in RET efficiency. Because of enhanced RET efficiency, the photobleaching dynamics of the fluorescent molecules at the surface of the nanoparticles is different from that of molecules in solution. The observed effect was used for detection of the functionalized nanoparticles within biological material rich with autofluorescent species. Synchrotron radiation deep-ultraviolet fluorescence microscopy is used to study the photobleaching dynamics of the fluorescence centers within human hepatocellular carcinoma Huh7.5.1 cells incubated with the nanoparticles. The fluorescent centers were classified according to their photobleaching dynamics, which enabled the discrimination of the cell areas where the accumulation of the nanoparticles takes place, even though the particles were smaller than the spatial resolution of the images.

Design of Novel Letrozole Analogues Targeting Aromatase for Breast Cancer: Molecular Docking, Molecular Dynamics, and Theoretical Studies on Gold Nanoparticles

The use of aromatase inhibitors is an established therapy for estrogen-dependent breast cancer in postmenopausal women. However, the only commercially available aromatase inhibitor, letrozole, is not highly selective; in addition to aromatase, it has an affinity for binding to desmolase, an enzyme involved in steroidogenesis, which explains the main side effects. Therefore, we designed new compounds based on the structure of letrozole. More than five thousand compounds were constructed based on the letrozole structure. Then, these compounds were screened for their binding ability toward the target protein, aromatase. Quantum docking, Glide docking, and ADME studies showed 14 new molecules with docking scores of ≤-7 kcal/mol, compared to the docking score of -4.109 kcal/mol of the reference, letrozole. Moreover, molecular dynamics (MD) and post-MD MM-GBSA calculations were calculated for the top three compounds, and the results supported in their interaction's stability. Finally, the density-functional theory (DFT) study applied to the top compound to study the interaction with gold nanoparticles revealed the most stable position for the interaction with the gold nanoparticles. The results of this study confirmed that these newly designed compounds could be useful starting points for lead optimization. Further in vitro and in vivo studies are recommended for these compounds to verify these promising results experimentally.

Inorganic nanoparticles as scaffolds for bioorthogonal catalysts

Bioorthogonal transition metal catalysts (TMCs) transform therapeutically inactive molecules (pro-drugs) into active drug compounds. Inorganic nanoscaffolds protect and solubilize catalysts while offering a flexible design space for decoration with targeting elements and stimuli-responsive activity. These "drug factories" can activate pro-drugs in situ, localizing treatment to the disease site and minimizing off-target effects. Inorganic nanoscaffolds provide structurally diverse scaffolds for encapsulating TMCs. This ability to define the catalyst environment can be employed to enhance the stability and selectivity of the TMC, providing access to enzyme-like bioorthogonal processes. The use of inorganic nanomaterials as scaffolds TMCs and the use of these bioorthogonal nanozymes in vitro and in vivo applications will be discussed in this review.

Inhibition of Polymicrobial Biofilms of Candida albicans-Staphylococcus aureus/Streptococcus mutans by Fucoidan-Gold Nanoparticles

The polymicrobial proliferation and development of complex biofilm morphologies by bacterial and fungal pathogens in the host are some of the key factors contributing to the failure of antimicrobial treatments. The polymicrobial interaction of Candida albicans and some bacterial species has been extensively studied in both in vitro and in vivo model systems. Alternative strategies for disrupting polymicrobial interaction and biofilm formation are constantly needed. Among several alternative strategies, the use of nanoparticles synthesized using a natural product in the treatment of microbial infection has been considered a promising approach. The current study aimed to synthesize gold nanoparticles (AuNPs) using a natural product, fucoidan, and to test their efficacy against mono and duo combinations of fungal (Candida albicans) and bacterial (Staphylococcus aureus/Streptococcus mutans) biofilms. Several methods were used to characterize and study Fu-AuNPs, including UV-vis absorption spectroscopy, FTIR, FE-TEM, EDS, DLS, zeta potential, and XRD. The concentration-dependent inhibition of early-stage biofilms and the eradication of mature biofilms of single species of C. albicans, S. aureus, and S. mutans have been observed. Early biofilms of a dual-species combination of C. albicans and S. aureus/S. mutans were also suppressed at an increasing concentration of Fu-AuNPs. Furthermore, Fu-AuNPs significantly eradicated the established mature biofilm of mixed species. The treatment method proposed in this study, which involves the use of marine-bioinspired nanoparticles, is a promising and biocompatible agent for preventing the growth of polymicrobial biofilms of bacterial and fungal pathogens.

Optimizing Dacarbazine Therapy: Design of a Laser-Triggered Delivery System Based on β-Cyclodextrin and Plasmonic Gold Nanoparticles

Dacarbazine (DB) is an antineoplastic drug extensively used in cancer therapy. However, present limitations on its performance are related to its low solubility, instability, and non-specificity. To overcome these drawbacks, DB was included in β-cyclodextrin (βCD), which increased its aqueous solubility and stability. This new βCD@DB complex has been associated with plasmonic gold nanoparticles (AuNPs), and polyethylene glycol (PEG) has been added in the process to increase the colloidal stability and biocompatibility. Different techniques revealed that DB allows for a dynamic inclusion into βCD, with an association constant of 80 M^-1 and a degree of solubilization of 0.023, where βCD showed a loading capacity of 16%. The partial exposure of the NH₂ group in the included DB allows its interaction with AuNPs, with a loading efficiency of 99%. The PEG-AuNPs-βCD@DB nanosystem exhibits an optical plasmonic absorption at 525 nm, a surface charge of -29 mV, and an average size of 12 nm. Finally, laser irradiation assays showed that DB can be released from this platform in a controlled manner over time, reaching a concentration of 56 μg/mL (43% of the initially loaded amount), which, added to the previous data, validates its potential for drug delivery applications. Therefore, the novel nanosystem based on βCD, AuNPs, and PEG is a promising candidate as a new nanocarrier for DB.

Nanotherapeutic Intervention in Photodynamic Therapy for Cancer

The clinical need for photodynamic therapy (PDT) has been growing for several decades. Notably, PDT is often used in oncology to treat a variety of tumors since it is a low-risk therapy with excellent selectivity, does not conflict with other therapies, and may be repeated as necessary. The mechanism of action of PDT is the photoactivation of a particular photosensitizer (PS) in a tumor microenvironment in the presence of oxygen. During PDT, cancer cells produce singlet oxygen (¹O₂) and reactive oxygen species (ROS) upon activation of PSs by irradiation, which efficiently kills the tumor. However, PDT's effectiveness in curing a deep-seated malignancy is constrained by three key reasons: a tumor's inadequate PS accumulation in tumor tissues, a hypoxic core with low oxygen content in solid tumors, and limited depth of light penetration. PDTs are therefore restricted to the management of thin and superficial cancers. With the development of nanotechnology, PDT's ability to penetrate deep tumor tissues and exert desired therapeutic effects has become a reality. However, further advancement in this field of research is necessary to address the challenges with PDT and ameliorate the therapeutic outcome. This review presents an overview of PSs, the mechanism of loading of PSs, nanomedicine-based solutions for enhancing PDT, and their biological applications including chemodynamic therapy, chemo-photodynamic therapy, PDT-electroporation, photodynamic-photothermal (PDT-PTT) therapy, and PDT-immunotherapy. Furthermore, the review discusses the mechanism of ROS generation in PDT advantages and challenges of PSs in PDT.

Hydrophilic gold nanospheres: influence of alendronate, memantine, and tobramycin on morphostructural features

Turkevich gold nanospheres are the original nanospheres that have been modified over time. Its combination with targeting medications such as alendronate, memantine, and tobramycin will provide additional benefits in targeting specific areas in the bone, brain, and microorganisms, respectively. Hence, The reactivity and stability of nanospheres with various drug concentrations (milli-,micro-, and nano-levels) have been studied. With alendronate, the absorbance spectra of nanospheres at [Formula: see text] 520 nm were always stable and no redshifts occurred. In contrast, the spectra with memantine and tobramycin were stable at the nano-level and redshifts occurred at the milli- and micro-levels. HRTEM and DLS revealed that the core diameter was relatively stable in all cases, whereas the hydrodynamic diameter and zeta potential varied with varying drug concentrations. Increasing concentration increased hydrodynamic diameter slightly with memantine (from 64.99 to 98.41 nm), dramatically with tobramycin (from 135.3 to 332.16 nm), and almost negligibly with alendronate (from 52.08 to 58.94 nm ). Zeta Potential, conversely, is reduced as concentration increases. Memantine had the greatest reduction in negativity, followed by tobramycin, but alendronate had a slight increase in negativity. Benefits from this research would be in targeted drug delivery, where stability and reactivity of gold nanospheres are critical.

Peptide-based assembled nanostructures that can direct cellular responses

Natural originated materials have been well-studied over the past several decades owing to their higher biocompatibility compared to the traditional polymers. Peptides, consisting of amino acids, are among the most popular programable building blocks, which is becoming a growing interest in nanobiotechnology. Structures assembled using those biomimetic peptides allow the exploration of chemical sequences beyond those been routinely used in biology. In this Review, we discussed the most recent experimental discoveries on the peptide-based assembled nanostructures and their potential application at the cellular level such as drug delivery. In particular, we explored the fundamental principles of peptide self-assembly and the most recent development in improving their interactions with biological systems. We believe that as the fundamental knowledge of the peptide assemblies evolves, the more sophisticated and versatile nanostructures can be built, with promising biomedical applications.

Nanotechnology in drug and gene delivery

Over the last decade, nanotechnology has widely addressed many nanomaterials in the biomedical area with an opportunity to achieve better-targeted delivery, effective treatment, and an improved safety profile. Nanocarriers have the potential property to protect the active molecule during drug delivery. Depending on the employing nanosystem, the delivery of drugs and genes has enhanced the bioavailability of the molecule at the disease site and exercised an excellent control of the molecule release. Herein, the chapter discusses various advanced nanomaterials designed to develop better nanocarrier systems used to face different diseases such as cancer, heart failure, and malaria. Furthermore, we demonstrate the great attention to the promising role of nanocarriers in ease diagnostic and biodistribution for successful clinical cancer therapy.

Nanoparticle delivery systems for substance use disorder

Innovative breakthroughs in nanotechnology are having a substantial impact in healthcare, especially for brain diseases where effective therapeutic delivery systems are desperately needed. Nanoparticle delivery systems offer an unmatched ability of not only conveying a diverse array of diagnostic and therapeutic agents across complex biological barriers, but also possess the ability to transport payloads to targeted cell types over a sustained period. In substance use disorder (SUD), many therapeutic targets have been identified in preclinical studies, yet few of these findings have been translated to effective clinical treatments. The lack of success is, in part, due to the significant challenge of delivering novel therapies to the brain and specific brain cells. In this review, we evaluate the potential approaches and limitations of nanotherapeutic brain delivery systems. We also highlight the examples of promising strategies and future directions of nanocarrier-based treatments for SUD.

Application and Prospect of CRISPR/Cas9 Technology in Reversing Drug Resistance of Non-Small Cell Lung Cancer

Cancer drug resistance has always been a major factor affecting the treatment of non-small cell lung cancer, which reduces the quality of life of patients. The clustered regularly interspaced short palindromic repeats/CRISPR associated protein 9 (CRISPR/Cas9) technology, as an efficient and convenient new gene-editing technology, has provided a lot of help to the clinic and accelerated the research of cancer and drug resistance. In this review, we introduce the mechanisms of drug resistance in non-small cell lung cancer (NSCLC), discuss how the CRISPR/Cas9 system can reverse multidrug resistance in NSCLC, and focus on drug resistance gene mutations. To improve the prognosis of NSCLC patients and further improve patients' quality of life, it is necessary to utilize the CRISPR/Cas9 system in systematic research on cancer drug resistance.

Multimeric RNAs for efficient RNA-based therapeutics and vaccines

There has been a growing interest in RNA therapeutics globally, and much progress has been made in this area, which has been further accelerated by the clinical applications of RNA-based vaccines against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Following these successful clinical trials, various technologies have been developed to improve the efficacy of RNA-based drugs. Multimerization of RNA therapeutics is one of the most attractive approaches to ensure high stability, high efficacy, and prolonged action of RNA-based drugs. In this review, we offer an overview of the representative approaches for generating repetitive functional RNAs by chemical conjugation, structural self-assembly, enzymatic elongation, and self-amplification. The therapeutic and vaccine applications of engineered multimeric RNAs in various diseases have also been summarized. By outlining the current status of multimeric RNAs, the potential of multimeric RNA as a promising treatment strategy is highlighted.

Tailored Nucleic Acid Architectures at Gold Surfaces for Controlled Therapeutic Release

Nucleic acids are versatile materials capable of forming smart nanocarriers with highly controllable therapeutic delivery. DNA-gated release is a mechanism by which DNA oligonucleotides physically block the release of encapsulated drugs from porous nanoparticles. We extend this mechanism to be used with drugs bound to the surface of DNA-capped gold nanoparticles (AuNPs). We investigated DNA monolayers of different thicknesses and hybridization states to determine how DNA surface architecture can affect the release of a template drug bound to the gold surface. DNA layers are investigated on the planar gold surface via quartz crystal microbalance with dissipation and on AuNPs via dynamic light scattering. The resultant layer architectures were studied for their effect on the release rate of drugs. We observed that varying DNA architectures on AuNPs result in different release rates of the drug. The rate of drug release can be slowed using either folded or randomly coiled DNA sequences, which act as a physical barrier to diffusion. DNA monolayers with upright orientation release drugs more quickly. When the longer single-stranded DNA is used, the drug release is slowed even further. However, even upright DNA layers provide a barrier to drug diffusion at longer sequence lengths. We hypothesize that it is the architecture of the DNA layer, influenced by the folded or upright orientation of individual DNA molecules, that affects the free diffusion of the drug away from the AuNP surface. This mechanism may improve the biological availability of many surface-bound drugs on solid, DNA-capped nanoparticles.

Nanotechnology Driven Cancer Chemoradiation: Exploiting the Full Potential of Radiotherapy with a Unique Combination of Gold Nanoparticles and Bleomycin

One of the major issues in current radiotherapy (RT) is the associated normal tissue toxicity. Enhancement of the RT effect with novel radiosensitizers can address this need. In this study, gold nanoparticles (GNPs) and bleomycin (BLM) were used as a unique combination of radiosensitizers. GNPs offer a two-fold promise as a delivery vehicle for BLM and as a radiosensitizing agent. In this study, GNPs were functionalized and complexed with BLM using a gold-thiol bond (denoted GNP-BLM). Our results show that there was a 40% and 10% decrease in cell growth with GNP-BLM vs. free BLM for the MIA PaCa-2 and PC-3 cell lines, respectively. Testing the GNP-BLM platform with RT showed an 84% and 13% reduction in cell growth in MIA PaCa-2 cells treated with GNP-BLM and GNPs, respectively. Similar results were seen with PC-3 cells. The efficacy of this approach was verified by mapping DNA double-strand breaks (DSBs) as well. Therefore, this proposed incorporation of nanomedicine with RT is promising in achieving a significantly higher therapeutic ratio which is necessary to make a paradigm change to the current clinical approach.

Dynamic Protein Corona of Gold Nanoparticles with an Evolving Morphology

Much has been learned about the protein coronae and their biological implications within the context of nanomedicine and nanotoxicology. However, no data is available about the protein coronae associated with nanoparticles undergoing spontaneous surface-energy minimization, a common phenomenon during the synthesis and shelf life of nanomaterials. Accordingly, here we employed gold nanoparticles (AuNPs) possessing the three initial states of spiky, midspiky, and spherical shapes and determined their acquisition of human plasma protein coronae with label-free mass spectrometry. The AuNPs collected coronal proteins that were different in abundance, physicochemical parameters, and interactive biological network. The size and structure of the coronal proteins matched the morphology of the AuNPs, where small globular proteins and large fibrillar proteins were enriched on spiky AuNPs, while large proteins were abundant on spherical AuNPs. Furthermore, the AuNPs induced endothelial leakiness to different degrees, which was partially negated by their protein coronae as revealed by confocal fluorescence microscopy, in vitro and ex vivo transwell assays, and signaling pathway assays. This study has filled a knowledge void concerning the dynamic protein corona of nanoparticles possessing an evolving morphology and shed light on their implication for future nanomedicine harnessing the paracellular pathway.

Inorganic Nanomaterial for Biomedical Imaging of Brain Diseases

In the past few decades, brain diseases have taken a heavy toll on human health and social systems. Magnetic resonance imaging (MRI), photoacoustic imaging (PA), computed tomography (CT), and other imaging modes play important roles in disease prevention and treatment. However, the disadvantages of traditional imaging mode, such as long imaging time and large noise, limit the effective diagnosis of diseases, and reduce the precision treatment of diseases. The ever-growing applications of inorganic nanomaterials in biomedicine provide an exciting way to develop novel imaging systems. Moreover, these nanomaterials with special physicochemical characteristics can be modified by surface modification or combined with functional materials to improve targeting in different diseases of the brain to achieve accurate imaging of disease regions. This article reviews the potential applications of different types of inorganic nanomaterials in vivo imaging and in vitro detection of different brain disease models in recent years. In addition, the future trends, opportunities, and disadvantages of inorganic nanomaterials in the application of brain diseases are also discussed. Additionally, recommendations for improving the sensitivity and accuracy of inorganic nanomaterials in screening/diagnosis of brain diseases.

Gold nanoparticles improve the embryonic developmental competency of artificially activated mouse oocytes

Currently, artificial oocyte activation has attracted wide attention in assisted reproduction due to extensive range of applications, particularly in somatic cell nuclear transfer and deriving pluripotent stem cell lines and it is the unique model to determine the role of paternal genome. Numbers of artificial activating agents have been used extensively to induce the oocytes activation; however, embryos developmental competency of artificially activated oocytes is still very low. In the present study, we determined the functional impact of strontium chloride supplementation with gold nanoparticles (AuNPs) in artificial oocytes activation and subsequent embryonic development. Oocytes were activated artificially in the culture medium containing 250 nM AuNPs with constant concentration of strontium chloride 10.00 mM. We found that adding 250 nM AuNPs with constant concentration of strontium chloride (10.00 mM for 3 hr) in culture medium improves the proportion of embryos reaching to the morula and blastocyst stages from 61.00% and 42.00% (controls) to 75.00% and 58.00% (250 nM AuNPs), respectively. In addition, foster mothers receiving AuNPs-treated embryos showed more implantation percentage and pregnancy rate relative to females received control embryos. Finally, embryos treated with 250 nM AuNPs concentration showed no toxic effect in term of blastocyst development. Collectively, our findings suggest the potential role of AuNPs in early embryonic development for mouse oocytes activated artificially and provide new insights in the field of animal biotechnology and assisted reproduction in humans.

Emerging Application of Magnetic Nanoparticles for Diagnosis and Treatment of Cancer

Cancer is a disease that has resulted in millions of deaths worldwide. The current conventional therapies utilized for the treatment of cancer have detrimental side effects. This led scientific researchers to explore new therapeutic avenues with an improved benefit to risk profile. Researchers have found nanoparticles, particles between the 1 and 100 nm range, to be encouraging tools in the area of cancer. Magnetic nanoparticles are one of many available nanoparticles at present. Magnetic nanoparticles have increasingly been receiving a considerable amount of attention in recent years owing to their unique magnetic properties, among many others. Magnetic nanoparticles can be controlled by an external magnetic field, signifying their ability to be site specific. The most popular approaches for the synthesis of magnetic nanoparticles are co-precipitation, thermal decomposition, hydrothermal, and polyol synthesis. The functionalization of magnetic nanoparticles is essential as it significantly increases their biocompatibility. The most utilized functionalization agents are comprised of polymers. The synthesis and functionalization of magnetic nanoparticles will be further explored in this review. The biomedical applications of magnetic nanoparticles investigated in this review are drug delivery, magnetic hyperthermia, and diagnosis. The diagnosis aspect focuses on the utilization of magnetic nanoparticles as contrast agents in magnetic resonance imaging. Clinical trials and toxicology studies relating to the application of magnetic nanoparticles for the diagnosis and treatment of cancer will also be discussed in this review.

Emerging trends in the application of gold nanoformulations in colon cancer diagnosis and treatment

Colorectal cancer is one of the most aggressive types of cancer with about two million new cases and one million deaths in 2020. The side effects of the available chemotherapies and the possibility of developing resistance against treatment highlight the importance of developing new therapeutic options. The development in the field of nanotechnology have introduced the application of nanoparticles (NPs) as a promising approach in the diagnosis and treatments of colorectal cancer and other types of cancer. Gold nanoparticles (AuNPs) are currently one of the most studied materials as they possess unique tunable properties allowing them to play a role in colorectal cancer bioimaging, diagnosis, and therapy. The high surface-to-volume ratio of AuNPs mediates their utilization in drug delivery as well as functionalization to provide specific targeting. Moreover, depending on their physical properties (size, shape), AuNPs can be modified to fit the intended application. However, there are contradictory results around the pharmacokinetics of AuNPs including their biodistribution, clearance, and toxicity. This variation of opinions is most likely due to the development of different AuNPs that vary in shape, size, and surface chemistry, in addition to the conditions under which each research was carried out. The conflicting data represent a challenge in the clinical use of AuNPs suggesting the need to understand the toxicity, fate, and long-term exposure of AuNPs in vivo. Thus, there is an unmet need for the establishment of a publicly available data base for extensive analysis. In this review, we discuss the recent advances in AuNP applications in the treatment and diagnosis of colorectal cancer, mechanisms of action, and clinical challenges.

Deep eutectic systems: An overview of fundamental aspects, current understanding and drug delivery applications

The deep eutectic system (DES) is a relatively new concept in the field of drug delivery science. DES is a class of eutectic mixtures comprised of two or more components, with a eutectic point far below than the melting temperature of the pure components. The strong hydrogen bonding interactions between DES constituents are responsible for significant lowering of melting point in DES. A significant number of molecules cannot reach from drug discovery phase to drug development phase because of poor biopharmaceutical attributes, such as solubility and permeability. DES can be a novel alternative to overcome these issues. In last few years DESs have been widely used in different pharmaceutical and chemical processes. However, comprehensive information regarding their drug delivery potential is not available. This review deals with fundamental aspects such as types, preparation, thermodynamics, toxicity, biodegradability and their applications in the field of drug delivery. Current challenges, future prospects and translational aspects of DES as drug delivery system have also been discussed.

Application of Gold Nanoparticle-Based Materials in Cancer Therapy and Diagnostics

Several metal nanoparticles have been developed for medical application. While all have their benefits, gold nanoparticles (AuNPs) are ideal in cancer therapy and diagnosis as they are chemically inert and minimally toxic. Several studies have shown the potential of AuNPs in the therapeutic field, as photosensitizing agents in sonochemical and photothermal therapy and as drug delivery, as well as in diagnostics and theranostics. Although there is a significant number of reviews on the application of AuNPs in cancer medicine, there is no comprehensive review on their application both in therapy and diagnostics. Therefore, considering the high number of studies on AuNPs’ applications, this review summarizes data on the application of AuNPs in cancer therapy and diagnostics. In addition, we looked at the influence of AuNPs’ shape and size on their biological properties. We also present the potential use of hybrid materials based on AuNPs in sonochemical and photothermal therapy and the possibility of their use in diagnostics. Despite their potential, the use of AuNPs and derivatives in cancer medicine still has some limitations. In this review, we provide an overview of the biological, physicochemical, and legal constraints on using AuNPs in cancer medicine.

Synthesis, Chemical-Physical Characterization, and Biomedical Applications of Functional Gold Nanoparticles: A Review

Relevant properties of gold nanoparticles, such as stability and biocompatibility, together with their peculiar optical and electronic behavior, make them excellent candidates for medical and biological applications. This review describes the different approaches to the synthesis, surface modification, and characterization of gold nanoparticles (AuNPs) related to increasing their stability and available features useful for employment as drug delivery systems or in hyperthermia and photothermal therapy. The synthetic methods reported span from the well-known Turkevich synthesis, reduction with NaBH4 with or without citrate, seeding growth, ascorbic acid-based, green synthesis, and Brust-Schiffrin methods. Furthermore, the nanosized functionalization of the AuNP surface brought about the formation of self-assembled monolayers through the employment of polymer coatings as capping agents covalently bonded to the nanoparticles. The most common chemical-physical characterization techniques to determine the size, shape and surface coverage of AuNPs are described underlining the structure-activity correlation in the frame of their applications in the biomedical and biotechnology sectors.

Pathways for Oral and Rectal Delivery of Gold Nanoparticles (1.7 nm) and Gold Nanoclusters into the Colon: Enteric-Coated Capsules and Suppositories

Two ways to deliver ultrasmall gold nanoparticles and gold-bovine serum albumin (BSA) nanoclusters to the colon were developed. First, oral administration is possible by incorporation into gelatin capsules that were coated with an enteric polymer. These permit the transfer across the stomach whose acidic environment damages many drugs. The enteric coating dissolves due to the neutral pH of the colon and releases the capsule's cargo. Second, rectal administration is possible by incorporation into hard-fat suppositories that melt in the colon and then release the nanocarriers. The feasibility of the two concepts was demonstrated by in-vitro release studies and cell culture studies that showed the easy redispersibility after dissolution of the respective transport system. This clears a pathway for therapeutic applications of drug-loaded nanoparticles to address colon diseases, such as chronic inflammation and cancer.

Real-Time Temperature Monitoring of Photoinduced Cargo Release inside Living Cells Using Hybrid Capsules Decorated with Gold Nanoparticles and Fluorescent Nanodiamonds

Real-time temperature monitoring within biological objects is a key fundamental issue for understanding the heating process and performing remote-controlled release of bioactive compounds upon laser irradiation. The lack of accurate thermal control significantly limits the translation of optical laser techniques into nanomedicine. Here, we design and develop hybrid (complex) carriers based on multilayered capsules combined with nanodiamonds (NV centers) as nanothermometers and gold nanoparticles (Au NPs) as nanoheaters to estimate an effective laser-induced temperature rise required for capsule rupture and further release of cargo molecules outside and inside cancerous (B16-F10) cells. We integrate both elements (NV centers and Au NPs) in the capsule structure using two strategies: (i) loading inside the capsule's cavity (CORE) and incorporating them inside the capsule's wall (WALL). Theoretically and experimentally, we show the highest and lowest heat release from capsule samples (CORE or WALL) under laser irradiation depending on the Au NP arrangement within the capsule. Applying NV centers, we measure the local temperature of capsule rupture inside and outside the cells, which is determined to be 128 ± 1.12 °C. Finally, the developed hybrid containers can be used to perform the photoinduced release of cargo molecules with simultaneous real-time temperature monitoring inside the cells.

Papain Mediated Synthesized Gold Nanoparticles Encore the Potency of Bioconjugated Flutamide

BACKGROUND

Prostate cancer is the second most common cause of male cancer death after lung cancer in the US. Therefore, there is an urgent need for a highly effective therapeutic drug at substantially low doses.

OBJECTIVE

Anti-androgen drug flutamide was delivered to the prostate cancer cells using Papain Mediated Synthesized Gold Nanoparticles (PGNPs) as the drug delivery system. PGNPs and flutamide worked synergistically against cancer cells.

METHODS

Flutamide was used to bioconjugate with PGNPs to improve its efficacy against prostate cancer. The synthesis and bioconjugation of flutamide with PGNPs (F-PGNPs) were characterized by various characterization techniques such as UV-vis spectroscopy, Transmission Electron Microscopy (TEM), Dynamic Light Scattering (DLS), and zeta potential to ensure the synthesis, size, shape, size distribution, and stability. The drug loading efficiency of flutamide in F-PGNPs was confirmed and validated by UV-vis spectroscopy. Eventually, in vitro studies were performed to determine the potency of F-PGNPs, changes in nuclear morphology, and generation of Reactive Oxygen Species (ROS).

RESULTS

The efficacy of F-PGNPs (IC₅₀ is 46.54 μg/mL) was found to be improved significantly over pure flutamide (IC50 is 64.63 μg/mL) against human prostate cancer PC-3 cell line whereas F-PGNPs did not show any significant toxicity up to a fairly high concentration toward normal mouse macrophage J774A.1 cells. The apoptotic effects and ROS generation of F-PGNPs were analyzed by increased permeability of the cell membrane and condensed chromatin with deep blue and green fluorescent nucleus, respectively.

DISCUSSION

The results clearly showed that F-PGNPs significantly improved the potency of flutamide by delivering it directly into the nucleus of cancer cells through caveolae-dependent endocytosis.

CONCLUSION

Thus, the greater inhibitory effect of F-PGNPs over the pure drug would be of great advantage during prostate cancer treatment.

Nanoparticles: A Hope for the Treatment of Inflammation in CNS

Neuroinflammation, an inflammatory response within the central nervous system (CNS), is a main hallmark of common neurodegenerative diseases, including Alzheimer’s disease (AD), Parkinson’s disease (PD), and amyotrophic lateral sclerosis (ALS), among others. The over-activated microglia release pro-inflammatory cytokines, which induces neuronal death and accelerates neurodegeneration. Therefore, inhibition of microglia over-activation and microglia-mediated neuroinflammation has been a promising strategy for the treatment of neurodegenerative diseases. Many drugs have shown promising therapeutic effects on microglia and inflammation. However, the blood–brain barrier (BBB)—a natural barrier preventing brain tissue from contact with harmful plasma components—seriously hinders drug delivery to the microglial cells in CNS. As an emerging useful therapeutic tool in CNS-related diseases, nanoparticles (NPs) have been widely applied in biomedical fields for use in diagnosis, biosensing and drug delivery. Recently, many NPs have been reported to be useful vehicles for anti-inflammatory drugs across the BBB to inhibit the over-activation of microglia and neuroinflammation. Therefore, NPs with good biodegradability and biocompatibility have the potential to be developed as an effective and minimally invasive carrier to help other drugs cross the BBB or as a therapeutic agent for the treatment of neuroinflammation-mediated neurodegenerative diseases. In this review, we summarized various nanoparticles applied in CNS, and their mechanisms and effects in the modulation of inflammation responses in neurodegenerative diseases, providing insights and suggestions for the use of NPs in the treatment of neuroinflammation-related neurodegenerative diseases.

Gold Nanoparticles- Boon in Cancer Theranostics

BACKGROUND

Cancer is the world's second-largest cause of death, with an estimated 9.6 million fatalities in 2018. Malignant tumour (cancer) is caused by a mixture of genetic modifications due to the environmental variables that tend to activate or inactivate different genes, ultimately resulting in neoplastic transformations. Cancer is a multi-stage process that results from the conversion of the ordinary cells to tumour cells and progresses from a pre-cancer lesion to abnormal growth.

METHODS

Chemotherapy inhibits the ability of the cells to divide rapidly in an abnormal manner, but this treatment simultaneously affects the entire cellular network in the human body leading to cytotoxic effects. In this review article, the same issue has been addressed by discussing various aspects of the newer class of drugs in cancer therapeutics, i.e., Gold Nanoparticles (AuNPs) from metal nanoparticle (NP) class.

RESULTS

Metal NPs are advantageous over conventional chemotherapy as the adverse drug reactions are lesser. Additionally, ease of drug delivery, targeting and gene silencing are salient features of this treatment. Functionalized ligand-targeting metal NPs provide better energy deposition control in tumour. AuNPs are promising agents in the field of cancer treatment and are comprehensively studied as contrast agents, carriers of medicinal products, radiosensitizers and photothermal agents. For the targeted delivery of chemotherapeutic agents, AuNPs are used and also tend to enhance tumour imaging in vivo for a variety of cancer types and diseased organs.

CONCLUSION

The first part of the review focuses on various nano-carriers that are used for cancer therapy and deals with the progression of metal NPs in cancer therapy. The second part emphasizes the use of nanotechnology by considering the latest studies for diagnostic and therapeutic properties of AuNPs. AuNPs present the latest studies in the field of nanotechnology, which leads to the development of early-stage clinical trials. The next part of the review discusses the major features of five principal types of AuNPs: gold nanorods, gold nanoshells, gold nanospheres, gold nanocages, and gold nanostars that have their application in photothermal therapy (PTT).

β-Cyclodextrin-Based Nanosponges Functionalized with Drugs and Gold Nanoparticles

Drugs are widely used as therapeutic agents; however, they may present some limitations. To overcome some of the therapeutic disadvantages of drugs, the use of β-cyclodextrin-based nanosponges (βCDNS) constitutes a promising strategy. βCDNS are matrices that contain multiple hydrophobic cavities, increasing the loading capacity, association, and stability of the included drugs. On the other hand, gold nanoparticles (AuNPs) are also used as therapeutic and diagnostic agents due to their unique properties and high chemical reactivity. In this work, we developed a new nanomaterial based on βCDNS and two therapeutic agents, drugs and AuNPs. First, the drugs phenylethylamine (PhEA) and 2-amino-4-(4-chlorophenyl)-thiazole (AT) were loaded on βCDNS. Later, the βCDNS-drug supramolecular complexes were functionalized with AuNPs, forming the βCDNS-PhEA-AuNP and βCDNS-AT-AuNP systems. The success of the formation of βCDNS and the loading of PhEA, AT, and AuNPs was demonstrated using different characterization techniques. The loading capacities of PhEA and AT in βCDNS were 90% and 150%, respectively, which is eight times higher than that with native βCD. The functional groups SH and NH2 of the drugs remained exposed and allowed the stabilization of the AuNPs, 85% of which were immobilized. These unique systems can be versatile materials with an efficient loading capacity for potential applications in the transport of therapeutic agents.

Potential anticancer activity of a new pro-apoptotic peptide-thioctic acid gold nanoparticle platform

Targeted nanoparticle platforms designed to induce cell death by apoptosis can bypass the resistance mechanisms of cancer cells. With this in mind we have constructed a new cancer-targeting peptide-functionalized nanoparticle using gold nanoparticles (AuNPs) and a thioctic acid-DMPGTVLP peptide (TA-peptide) conjugate. Morphological analysis of the nanoparticles by transmission electron microscopy showed average diameters of about 3.52 nm and 26.2 nm for the AuNP core and shell, respectively. Strong affinity toward the nucleolin receptors of breast cancer cell lines MCF-7 and T47D was observed for the TA-peptide gold nanoparticles (TAP@AuNPs) based on IC₅₀ values. Furthermore, the nanoparticles showed excellent hemocompatibility. Quantitative results of atomic absorption showed improved uptake of TAP@AuNPs. Treatment of the cells with TAP@AuNPS resulted in greater release of cytochrome c following caspase-3/7 activation compared with free TA-peptide. The cytosolic level of adenosine triphosphate for TAP@AuNPs was higher than in controls. Higher anti-tumor efficiency was observed for TAP@AuNPs than TA-peptide compared with phosphate-buffered saline after intratumoral injection in tumor-bearing mice. It can be concluded that the design and development of a receptor-specific peptide-AuNP platform will be valuable for theranostic applications in cancer nanomedicine.

The Interplay of Ligand Properties and Core Size Dictates the Hydrophobicity of Monolayer-Protected Gold Nanoparticles

The hydrophobicity of monolayer-protected gold nanoparticles is a crucial design parameter that influences self-assembly, preferential binding to proteins and membranes, and other nano-bio interactions. Predicting the effects of monolayer components on nanoparticle hydrophobicity is challenging due to the nonadditive, cooperative perturbations to interfacial water structure that dictate hydrophobicity at the nanoscale. In this work, we quantify nanoparticle hydrophobicity by using atomistic molecular dynamics simulations to calculate local hydration free energies at the nanoparticle-water interface. The simulations reveal that the hydrophobicity of large gold nanoparticles is determined primarily by ligand end group chemistry, as expected. However, for small gold nanoparticles, long alkanethiol ligands interact to form anisotropic bundles that lead to substantial spatial variations in hydrophobicity even for homogeneous monolayer compositions. We further show that nanoparticle hydrophobicity is modulated by changing the ligand structure, ligand chemistry, and gold core size, emphasizing that single-ligand properties alone are insufficient to characterize hydrophobicity. Finally, we illustrate that hydration free energy measurements correlate with the preferential binding of propane as a representative hydrophobic probe molecule. Together, these results show that both physical and chemical properties influence the hydrophobicity of small nanoparticles and must be considered together when predicting gold nanoparticle interactions with biomolecules.

Synthesis and bioconjugation of alkanethiol-stabilized gold bipyramid nanoparticles

Gold bipyramid (GBP) nanoparticles are promising for a range of biomedical applications, including biosensing and surface-enhanced Raman spectroscopy, due to their favorable optical properties and ease of chemical functionalization. Here we report improved synthesis methods, including preparation of gold seed particles with an increased shelf life of ∼1 month, and preparation of GBPs with significantly shortened synthesis time (< 1 h). We also report methods for the functionalization and bioconjugation of the GBPs, including functionalization with alkanethiol self-assembled monolayers (SAMs) and bioconjugation with proteins via carbodiimide cross-linking. Binding of specific antibodies to the nanoparticle-bound proteins was subsequently observed via localized surface plasmon resonance sensing. Rabbit IgG and goat anti-Rabbit IgG antibodies were used as a model system for antibody-antigen interactions. As-synthesized, SAM-functionalized, and bioconjugated bipyramids were characterized using scanning electron microscopy, UV-vis spectroscopy, zeta potential, and dynamic light scattering.

Composition of Intracellular Protein Corona around Nanoparticles during Internalization

It has been well established that the early-stage interactions of nanoparticles with cells are governed by the extracellular protein corona. However, after entering into the cells, the evolving protein corona is the key to subsequent processing of nanoparticles by cells. To identify the protein corona around intracellular nanoparticles, it is essential to maintain its original compositions during cell treatment. Herein, we develop a paraformaldehyde (PFA) cross-linking strategy to stabilize corona compositions when extracting protein coronas from cells, providing original information on protein coronas around intercellular gold nanoparticles (AuNPs). The stability of the protein corona after PFA cross-linking was carefully investigated with several characterization methods, and the results demonstrate that PFA cross-linking successfully prevents the dissociation and exchange of corona proteins. Then the recovered intracellular protein corona around AuNPs from living HepG2 cells with a PFA cross-linking strategy was subjected to nanoHPLC-MS/MS for proteomic analysis. It was found that the compositions of intracellular protein coronas are dominated by cell-derived proteins and undergo significant variation of protein species and amounts over time during internalization. Time-resolved analysis provides relevant proteins involved in nanoparticle cellular uptake and transportation, indicating that AuNPs are endocytosed mainly by a clathrin-mediated uptake mechanism and directed into an endolysosomal pathway toward their final destination. Such proteomic-based results are verified by pharmacological inhibition and TEM imaging analysis. This work provides a universal strategy to study compositions of protein corona around intercellular nanoparticles and could be a footstone to link the formation of protein corona around nanoparticles to their biological function in cells.

Following cytotoxic nanoconjugates from injection to halting the cell cycle machinery and its therapeutic implications in oral cancer

BACKGROUND

The concept of personalized therapy has been proven to be a promising approach. A popular technique is to utilize gold nanoparticles (AuNPs) as drug delivery vectors for cytotoxic drugs and small molecule inhibitors to target and eradicate oral cancer cells in vitro and in vivo. Both drug and nanocarrier designs play important roles in the treatment efficacy. In our study, we standardized the nanosystem regarding NPs type, size, surface ligands and coverage percentage leaving only the drugs mode of action as the confounding variable. We propose that similarly constructed nanoparticles (NPs) can selectively leverage different conjugated drugs irrelevant to their original mode of action. If proven, AuNPs may have a secondary role beyond bypassing cancer cell membrane and delivering their loaded drugs.

METHODS

We conjugated 5- fluorouracil (5Fu), camptothecin (CPT), and a fibroblast growth factor receptor1-inhibitor (FGFR1i) to gold nanospheres (AuNSs). We followed their trajectories in Syrian hamsters with chemically induced buccal carcinomas.

RESULTS

Flow cytometry and cell cycle data shows that 5Fu- and CPT- induced a similar ratio of S-phase cell cycle arrest as nanoconjugates and in their free forms. On the other hand, FGFR1i-AuNSs induced significant sub-G1 cell population compared with its free form. Despite cell cycle dynamics variability, there was no significant difference in tumor cells' proliferation rate between CPT-, 5Fu- and FGFR1i- AuNSs treated groups. In our in vivo model, FGFR1i-AuNSs induced the highest tumor reduction rates followed by 5Fu- AuNSs. CPT-AuNSs induced significantly lower tumor reduction rates compared with the 5Fu- and FGFR1i- AuNSs despite showing similar proliferative rates in tumor cells.

CONCLUSIONS

Our data indicates that the cellular biological events do not predict the outcome seen in our in vivo model. Furthermore, our results suggest that AuNSs selectively enhance the therapeutic effect of small molecule inhibitors such as FGFR1i than potent anticancer drugs. Future studies are required to better understand the underlying mechanism.

Recent Advances in Bio-Templated Metallic Nanomaterial Synthesis and Electrocatalytic Applications

Developing metallic nanocatalysts with high reaction activity, selectivity and practical durability is a promising and active subfield in electrocatalysis. In the classical "bottom-up" approach to synthesize stable nanomaterials by chemical reduction, stabilizing additives such as polymers or organic surfactants must be present to cap the nanoparticle to prevent material bulk aggregation. In recent years, biological systems have emerged as green alternatives to support the uncoated inorganic components. One key advantage of biological templates is their inherent ability to produce nanostructures with controllable composition, facet, size and morphology under ecologically friendly synthetic conditions, which are difficult to achieve with traditional inorganic synthesis. In addition, through genetic engineering or bioconjugation, bio-templates can provide numerous possibilities for surface functionalization to incorporate specific binding sites for the target metals. Therefore, in bio-templated systems, the electrocatalytic performance of the formed nanocatalyst can be tuned by precisely controlling the material surface chemistry. With controlled improvements in size, morphology, facet exposure, surface area and electron conductivity, bio-inspired nanomaterials often exhibit enhanced catalytic activity towards electrode reactions. In this Review, recent research developments are presented in bio-approaches for metallic nanomaterial synthesis and their applications in electrocatalysis for sustainable energy storage and conversion systems.

The Effects of a Varied Gold Shell Thickness on Iron Oxide Nanoparticle Cores in Magnetic Manipulation, T1 and T2 MRI Contrasting, and Magnetic Hyperthermia

Fe₃O₄–Au core–shell magnetic-plasmonic nanoparticles are expected to combine both magnetic and light responsivity into a single nanosystem, facilitating combined optical and magnetic-based nanotheranostic (therapeutic and diagnostic) applications, for example, photothermal therapy in conjunction with magnetic resonance imaging (MRI) imaging. To date, the effects of a plasmonic gold shell on an iron oxide nanoparticle core in magnetic-based applications remains largely unexplored. For this study, we quantified the efficacy of magnetic iron oxide cores with various gold shell thicknesses in a number of popular magnetic-based nanotheranostic applications; these included magnetic sorting and targeting (quantifying magnetic manipulability and magnetophoresis), MRI contrasting (quantifying benchtop nuclear magnetic resonance (NMR)-based T₁ and T₂ relaxivity), and magnetic hyperthermia therapy (quantifying alternating magnetic-field heating). We observed a general decrease in magnetic response and efficacy with an increase of the gold shell thickness, and herein we discuss possible reasons for this reduction. The magnetophoresis speed of iron oxide nanoparticles coated with the thickest gold shell tested here (ca. 42 nm) was only ca. 1% of the non-coated bare magnetic nanoparticle, demonstrating reduced magnetic manipulability. The T₁ relaxivity, r₁, of the thick gold-shelled magnetic particle was ca. 22% of the purely magnetic counterpart, whereas the T₂ relaxivity, r₂, was 42%, indicating a reduced MRI contrasting. Lastly, the magnetic hyperthermia heating efficiency (intrinsic loss power parameter) was reduced to ca. 14% for the thickest gold shell. For all applications, the efficiency decayed exponentially with increased gold shell thickness; therefore, if the primary application of the nanostructure is magnetic-based, this work suggests that it is preferable to use a thinner gold shell or higher levels of stimuli to compensate for losses associated with the addition of the gold shell. Moreover, as thinner gold shells have better magnetic properties, have previously demonstrated superior optical properties, and are more economical than thick gold shells, it can be said that “less is more”.