Gold nanoparticles functionalized with therapeutic and targeted peptides for cancer treatment

Role of Functionalized Peptides in Nanomedicine for Effective Cancer Therapy

Peptide-functionalized nanomedicine, which addresses the challenges of specificity and efficacy in drug delivery, is emerging as a pivotal approach for cancer therapy. Globally, cancer remains a leading cause of mortality, and conventional treatments, such as chemotherapy, often lack precision and cause adverse effects. The integration of peptides into nanomedicine offers a promising solution for enhancing the targeting and delivery of therapeutic agents. This review focuses on the three primary applications of peptides: cancer cell-targeting ligands, building blocks for self-assembling nanostructures, and elements of stimuli-responsive systems. Nanoparticles modified with peptides improved targeting of cancer cells, minimized damage to healthy tissues, and optimized drug delivery. The versatility of self-assembled peptide structures makes them an innovative vehicle for drug delivery by leveraging their biocompatibility and diverse nanoarchitectures. In particular, the mechanism of cell death induced by self-assembled structures offers a novel approach to cancer therapy. In addition, peptides in stimuli-responsive systems enable precise drug release in response to specific conditions in the tumor microenvironment. The use of peptides in nanomedicine not only augments the efficacy and safety of cancer treatments but also suggests new research directions. In this review, we introduce systems and functionalization methods using peptides or peptide-modified nanoparticles to overcome challenges in the treatment of specific cancers, including breast cancer, lung cancer, colon cancer, prostate cancer, pancreatic cancer, liver cancer, skin cancer, glioma, osteosarcoma, and cervical cancer.

An application of carbohydrate polymers-based surface-modified gold nanoparticles for improved target delivery to liver cancer therapy - A systemic review

Gold nanoparticles have been broadly investigated as cancer diagnostic and therapeutic agents. Gold nanoparticles are a favorable drug delivery vehicle with their unique subcellular size and good biocompatibility. Chitosan, agarose, fucoidan, porphyran, carrageenan, ulvan and alginate are all examples of biologically active macromolecules. Since they are biocompatible, biodegradable, and irritant-free, they find extensive application in biomedical and macromolecules. The versatility of these compounds is enhanced because they are amenable to modification by functional groups like sulfation, acetylation, and carboxylation. In an eco-friendly preparation process, the biocompatibility and targeting of GNPs can be improved by functionalizing them with polysaccharides. This article provides an update on using carbohydrate-based GNPs in liver cancer treatment, imaging, and drug administration. Selective surface modification of several carbohydrate types and further biological uses of GNPs are focused on.

Gold Nanoparticle-Based Colorimetric Biosensing for Foodborne Pathogen Detection

Ensuring safe high-quality food is an ongoing priority, yet consumers face heightened risk from foodborne pathogens due to extended supply chains and climate change in the food industry. Nanomaterial-based assays are popular and have recently been developed to ensure food safety and high quality. This review discusses strategies for utilizing gold nanoparticles in colorimetric biosensors. The visible-signal biosensor proves to be a potent sensing technique for directly measuring targets related to foodborne pathogens in the field of food analysis. Among visible-signal biosensors, the localized surface plasmon resonance (LSPR) biosensor has garnered increasing attention and experienced rapid development in recent years. This review succinctly introduces the origin of LSPR theory, providing detailed insights into its fundamental principles. Additionally, this review delves into the application of nanotechnology for the implementation of the LSPR biosensor, exploring methods for utilizing gold nanoparticles and elucidating the factors that influence the generation of visible signals. Several emerging technologies aimed at simple and rapid immunoassays for onsite applications have been introduced in the food industry. In the foreseeable future, field-friendly colorimetric biosensors could be adopted in food monitoring systems. The onsite and real-time detection of possible contaminants and biological substances in food and water is essential to ensure human health and safety.

Design and Characterization of pMyc/pMax Peptide-Coupled Gold Nanosystems for Targeting Myc in Prostate Cancer Cell Lines

Myc and Max are essential proteins in the development of prostate cancer. They act by dimerizing and binding to E-box sequences. Disrupting the Myc:Max heterodimer interaction or its binding to E-box sequences to interrupt gene transcription represent promising strategies for treating cancer. We designed novel pMyc and pMax peptides from reference sequences, and we evaluated their ability to bind specifically to E-box sequences using an electrophoretic mobility shift assay (EMSA). Then, we assembled nanosystems (NSs) by coupling pMyc and pMax peptides to AuNPs, and determined peptide conjugation using UV-Vis spectroscopy. After that, we characterized the NS to obtain the nanoparticle's size, hydrodynamic diameter, and zeta potential. Finally, we evaluated hemocompatibility and cytotoxic effects in three different prostate adenocarcinoma cell lines (LNCaP, PC-3, and DU145) and a non-cancerous cell line (Vero CCL-81). EMSA results suggests peptide-nucleic acid interactions between the pMyc:pMax dimer and the E-box. The hemolysis test showed little hemolytic activity for the NS at the concentrations (5, 0.5, and 0.05 ng/µL) we evaluated. Cell viability assays showed NS cytotoxicity. Overall, results suggest that the NS with pMyc and pMax peptides might be suitable for further research regarding Myc-driven prostate adenocarcinomas.

Chemical Modification of Tiopronin for Dual Management of Cystinuria and Associated Bacterial Infections

Cystinuria is an inherited autosomal recessive disease of the kidneys of recurring nature that contributes to frequent urinary tract infections due to bacterial growth and biofilm formation surrounding the stone microenvironment. In the past, commonly used strategies for managing cystinuria involved the use of (a) cystine crystal growth inhibitors such as l-cystine dimethyl ester and lipoic acid, and (b) thiol-based small molecules such as N-(2-mercaptopropionyl) glycine, commonly known as tiopronin, that reduce the formation of cystine crystals by reacting with excess cystine and generating more soluble disulfide compounds. However, there is a dearth of simplistic chemical approaches that have focused on the dual treatment of cystinuria and the associated microbial infections. This work strategically exploited a single chemical approach to develop a nitric oxide (NO)-releasing therapeutic compound, S-nitroso-2-mercaptopropionyl glycine (tiopronin-NO), for the dual management of cystine stone formation and the related bacterial infections. The results successfully demonstrated that (a) the antibacterial activity of NO rendered tiopronin-NO effective against the stone microenvironment inhabitants, Escherichia coli and Pseudomonas aeruginosa, and (b) tiopronin-NO retained the ability to undergo disulfide exchange with cystine while being reported to be safe against canine kidney and mouse fibroblast cells. Thus, the synthesis of such a facile molecule aimed at the dual management of cystinuria and related infections is unprecedented in the literature.

Surface Functionalization of Gold Nanoparticles for Targeting the Tumor Microenvironment to Improve Antitumor Efficiency

Gold nanoparticles (AuNPs) have undergone significant research for their use in the treatment of cancer. Numerous researchers have established their potent antitumor properties, which have greatly impacted the treatment of cancer. AuNPs have been used in four primary anticancer treatment modalities, namely radiation, photothermal therapy, photodynamic therapy, and chemotherapy. However, the ability of AuNPs to destroy cancer is lacking and can even harm healthy cells without the right direction to transport them to the tumor microenvironment. Consequently, a suitable targeting technique is needed. Based on the distinct features of the human tumor microenvironment, this review discusses four different targeting strategies that target the four key features of the tumor microenvironment, including abnormal vasculature, overexpression of specific receptors, an acidic microenvironment, and a hypoxic microenvironment, to direct surface-functionalized AuNPs to the tumor microenvironment and increase antitumor efficacies. In addition, some current completed or ongoing clinical trials of AuNPs will also be discussed below to further reinforce the concept of using AuNPs in anticancer therapy.

Refinement of safety and efficacy of anti-cancer chemotherapeutics by tailoring their site-specific intracellular bioavailability through transporter modulation

Low intracellular bioavailability, off-site toxicities, and multi drug resistance (MDR) are the major constraints involved in cancer chemotherapy. Many anticancer molecules fail to become a good lead in drug discovery because of their poor site-specific bioavailability. Concentration of a molecule at target sites is largely varied because of the wavering expression of transporters. Recent anticancer drug discovery strategies are paying high attention to enhance target site bioavailability by modulating drug transporters. The level of genetic expression of transporters is an important determinant to understand their ability to facilitate drug transport across the cellular membrane. Solid carrier (SLC) transporters are the major influx transporters involved in the transportation of most anti-cancer drugs. In contrast, ATP-binding cassette (ABC) superfamily is the most studied class of efflux transporters concerning cancer and is significantly involved in efflux of chemotherapeutics resulting in MDR. Balancing SLC and ABC transporters is essential to avoid therapeutic failure and minimize MDR in chemotherapy. Unfortunately, comprehensive literature on the possible approaches of tailoring site-specific bioavailability of anticancer drugs through transporter modulation is not available till date. This review critically discussed the role of different specific transporter proteins in deciding the intracellular bioavailability of anticancer molecules. Different strategies for reversal of MDR in chemotherapy by incorporation of chemosensitizers have been proposed in this review. Targeted strategies for administration of the chemotherapeutics to the intracellular site of action through clinically relevant transporters employing newer nanotechnology-based formulation platforms have been explained. The discussion embedded in this review is timely considering the current need of addressing the ambiguity observed in pharmacokinetic and clinical outcomes of the chemotherapeutics in anti-cancer treatment regimens.

Modification of α-Tocopherol Succinate with a Tumor-targeting Peptide Conjugate Enhances the Antitumor Efficacy of a Paclitaxel-loaded Lipid Aggregate

Paclitaxel (PTX) is a widely used chemotherapeutic agent in the clinic. However, its clinical benefit is limited due to its low water solubility, off-target toxicity, and for being a multidrug-resistant (MDR) substrate. To overcome these limitations in this study, a tumor-targeting peptide (CRGDK peptide, a ligand for NRP-1 receptor) conjugate of α-tocopheryl succinate (α-TOS) was synthesized and modified on PTX-loaded lipid aggregate (TL-PTX) to leverage the benefits of α-TOS, which include a) anti-cancer activity, b) increased PTX loading, and c) inhibition of MDR activity. Use of peptide conjugate of α-TOS (α-TOS-CRGDK) in lipid aggregate increased PTX entrapment efficiency by 20%, helped in NRP-1 specific cellular uptake and significantly enhanced apoptotic and cell killing activity (p <0.01) of PTX compared to control formulation (CL-PTX) by inhibiting MDR-activity in melanoma resulting in ∼70% increment in overall survival of melanoma tumor-bearing mice. In conclusion, CRGDK- α-TOS conjugate in association with PTX-loaded liposome provided a unique NRP-1 targeted, drug-resistant reversing anticancer regimen for treating aggressive melanoma.

Ion-Mediated Protein Stabilization on Nanoscopic Surfaces

The emergence of nanoparticles in biomedical applications has made their interactions with proteins inevitable. Nanoparticles conjugated with proteins and peptide-based constructs form an integral part of nanotherapeutics and have recently shown promise in treating a myriad of diseases. The proper functioning of proteins is critical to achieve their biological functions. However, interface issues result in the denaturation of proteins, and the loss of orientation and steric hindrance can adversely affect the function of the conjugate. Furthermore, surface-induced denaturation also triggers protein aggregation, resulting in amyloid-like species. Understanding the mechanistic underpinnings of protein-nanoparticle interactions and controlling their interfacial characteristics are critical and challenging due to the complex nature of the conjugates. In this milieu, we demonstrate that ionic liquids can be suitable candidates for stabilizing protein-nanoparticle interactions by virtue of their excellent protein-preserving properties. We also probe the previously unexplored mechanism of ion-mediated stabilization of the protein molecules on the nanoparticle surface. The protein-nanoparticle conjugates consist of lysozyme and choline-based ionic liquids characterized by optical and electron microscopy techniques combined with surface-sensitive plasmon-enhanced Raman spectroscopy. Furthermore, atomistic molecular dynamics simulations of the conjugates delineate interfacial interactions of the protein molecules and the modulation by the ions, particularly the conformational changes and the dynamic correlation when the protein and specific ionic liquid molecules are adsorbed on the nanoparticle surface. The combined experimental and computational studies showed the synergistic behavior of the ions of the ionic liquids, specifically the orientation and coverage of the anions aided by the cations to control the surface interactions and hence the overall protein stability. These studies pave the way for using ionic liquids, particularly their biocompatible counterparts in nanoparticle-based complexes, as stabilizing agents for biomedical applications.

Nanomaterials in anticancer applications and their mechanism of action - A review

The current challenges in cancer treatment using conventional therapies have made the emergence of nanotechnology with more advancements. The exponential growth of nanoscience has drawn to develop nanomaterials (NMs) with therapeutic activities. NMs have enormous potential in cancer treatment by altering the drug toxicity profile. Nanoparticles (NPs) with enhanced surface characteristics can diffuse more easily inside tumor cells, thus delivering an optimal concentration of drugs at tumor site while reducing the toxicity. Cancer cells can be targeted with greater affinity by utilizing NMs with tumor specific constituents. Furthermore, it bypasses the bottlenecks of indiscriminate biodistribution of the antitumor agent and high administration dosage. Here, we focus on the recent advances on the use of various nanomaterials for cancer treatment, including targeting cancer cell surfaces, tumor microenvironment (TME), organelles, and their mechanism of action. The paradigm shift in cancer management is achieved through the implementation of anticancer drug delivery using nano routes.

SARS-CoV-2 and its new variants: a comprehensive review on nanotechnological application insights into potential approaches

SARS-CoV-2 (COVID-19) spreads and develops quickly worldwide as a new global crisis which has left deep socio-economic damage and massive human mortality. This virus accounts for the ongoing outbreak and forces an urgent need to improve antiviral therapeutics and targeted diagnosing tools. Researchers have been working to find a new drug to combat the virus since the outbreak started in late 2019, but there are currently no successful drugs to control the SARS-CoV-2, which makes the situation riskier. Very recently, new variant of SARS-CoV-2 is identified in many countries which make the situation very critical. No successful treatment has yet been shown although enormous international commitment to combat this pandemic and the start of different clinical trials. Nanomedicine has outstanding potential to solve several specific health issues, like viruses, which are regarded a significant medical issue. In this review, we presented an up-to-date drug design strategy against SARS-CoV-2, including the development of novel drugs and repurposed product potentials were useful, and successful drugs discovery is a constant requirement. The use of nanomaterials in treatment against SARS-CoV-2 and their use as carriers for the transport of the most frequently used antiviral therapeutics are discussed systematically here. We also addressed the possibilities of practical applications of nanoparticles to give the status of COVID-19 antiviral systems.

Resveratrol: Its Path from Isolation to Therapeutic Action in Eye Diseases

Due to the confirmed therapeutic potential of resveratrol (Rv) for eye diseases, namely its powerful anti-angiogenic and antioxidant effects, this molecule must be studied more deeply. Nowadays, the pharmaceutic and pharmacokinetic available studies offer a troubling picture because of its low stability and bioavailability. To overcome this problem, researchers started to design and create different delivery systems that could improve the delivery amount of Rv. Therefore, this review aims to shed light on the proper and efficient techniques to isolate, purify and quantify the Rv molecule, and how this therapeutic molecule can be a part of a delivery system. The Rv great impact on aspects regarding its stability, bioavailability and absorption are also debated here, based on the existent literature on in vitro and in vivo human and animal studies. Moreover, after its absorption the Rv influence at the molecular level in ocular pathologies is described. In addition, the present review summarizes the available literature about Rv, hoping that Rv will gain more attention to investigate its unexplored side.

Functionalized Peptide-Based Nanoparticles for Targeted Cancer Nanotherapeutics: A State-of-the-Art Review

Cancer mortality is increasing at an alarming rate across the globe. Albeit, many therapeutics are available commercially, they are not effective and have no cure up to today. Moreover, the knowledge gap in cancer therapy persists, representing a potential blind spot for the innovation of effective anticancer therapeutics. This review presents an update on current advancements in nanopeptide therapeutics. Herein, a detailed exploration of peptide-functionalized nanoparticles for the development of nanotherapeutics was carried out. Different approaches that include self-assembly nanostructures, solid phase peptide synthesis, ligand exchange, chemical reduction, and conjugation methods for assembling peptides for functionalizing nanodrugs are also highlighted. An outlook on biomedical applications is also reviewed. Additionally, a comprehensive discussion on targeted cancer cell therapy and mechanism of action are provided. The present review reflects the functional novelty of nanodrugs to improve stability, accessibility, bioavailability, and specificity toward cancerous cells. Finally, it summarizes the current challenges and future perspectives on the formulation of these nanodrugs.

Progress on Applying Carbon Dots for Inhibition of RNA Virus Infection

Viral infection is a globally leading health issue. Annually, new lethal RNA viruses unexpectedly emerged and mutated threatening health and safety. Meanwhile, it is urgent to explore novel antiviral agents, which, however, takes years to be clinically available. Nonetheless, the development of carbon dots (CDs) in the past 20 years has exhibited their vast application potentials and revealed their promising capacity as future antiviral agents considering their versatile properties and significant antiviral responses. Thus, CDs have been widely investigated as an alternative of traditional chemotherapy for inhibiting viral infection and replication in vitro. Meanwhile, attempts to apply CDs to in vivo systems are in high demand. In this review, recent developments of CDs-based antiviral therapies are systematically summarized. Furthermore, the role of CDs in photodynamic inactivation to kill viruses or bacteria is briefly discussed.

Bifunctional Calix[4]arene-Coated Gold Nanoparticles for Orthogonal Conjugation

Gold nanoparticles (AuNPs) are currently intensively exploited in the biomedical field as they possess interesting chemical and optical properties. Although their synthesis is well-known, their controlled surface modification with defined densities of ligands such as peptides, DNA, or antibodies remains challenging and has generally to be optimized case by case. This is particularly true for applications like in vivo drug delivery that require AuNPs with multiple ligands, for example a targeting ligand and a drug in well-defined proportions. In this context, we aimed to develop a calixarene-modification strategy that would allow the controlled orthogonal conjugation of AuNPs, respectively, via amide bond formation and copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC). To do this, we synthesized a calix[4]arene-tetradiazonium salt bearing four PEG chains ended by an alkyne group (C1) and, after optimization of its grafting on 20 nm AuNPs, we demonstrated that CuAAC can be used to conjugate an azide containing dye (N₃-cya7.5). It was observed that AuNPs coated with C1 (AuNPs-C1) can be conjugated to approximately 600 N₃-cya7.5 that is much higher than the value obtained for AuNPs decorated with traditional thiolated PEG ligands terminated by an alkyne group. The control over the number of molecules conjugated via CuAAC was even possible by incorporating a non-functional calixarene (C2) into the coating layer. We then combined C1 with a calix[4]arene-tetradiazonium salt bearing four carboxyl groups (C3) that allows conjugation of an amine (NH₂-cya7.5) containing dye. The conjugation potential of these bifunctional AuNPs-C1/C3 was quantified by UV-vis spectroscopy: AuNPs decorated with equal amount of C1 and C3 could be conjugated to approximately 350 NH₂-dyes and 300 N₃-dyes using successively amide bond formation and CuAAC, demonstrating the control over the orthogonal conjugation. Such nanoconstructs could benefit to anyone in the need of a controlled modification of AuNPs with two different molecules via two different chemistries.

Multiparametric cytotoxicity assessment: the effect of gold nanoparticle ligand functionalization on SKOV3 ovarian carcinoma cell death

Gold nanoparticles (AuNP) are promising anti-cancer agents because of their modifiable properties and high biocompatibility. This study used multiple parallel analyses to investigate the cytotoxic properties of 5 nm AuNP conjugated to four different ligands with distinct surface chemistry: polyethylene glycol (PEG), trimethylammonium bromide (TMAB), 4-dimethylaminopyridine (DMAP), and carboxyl (COOH). We used a range of biochemical and high-content microscopy methods to evaluate the metabolic function, oxidative stress, cell health, cell viability, and cell morphology in SKOV3 ovarian cancer cells. Each AuNP displayed a distinct cytotoxicity profile. All AuNP species assessed exhibited signs of dose-dependent cytotoxicity when morphology, clonogenic survival, lysosomal uptake, or cell number were measured as the marker of toxicity. All particles except for AuNP-COOH increased SKOV3 apoptosis. In contrast, AuNP-TMAB was the only particle that did not alter the metabolic function or induce significant signs of oxidative stress. These results demonstrate that AuNP surface chemistry impacts the magnitude and mechanism of SKOV3 cell death. Together, these findings reinforce the important role for multiparametric cytotoxicity characterization when considering the utility of novel particles and surface chemistries.

Monodisperse Gold Nanoparticles: A Review on Synthesis and Their Application in Modern Medicine

Gold nanoparticles (AuNPs) are becoming increasingly popular as drug carriers due to their unique properties such as size tenability, multivalency, low toxicity and biocompatibility. AuNPs have physical features that distinguish them from bulk materials, small molecules and other nanoscale particles. Their unique combination of characteristics is just now being fully realized in various biomedical applications. In this review, we focus on the research accomplishments and new opportunities in this field, and we describe the rising developments in the use of monodisperse AuNPs for diagnostic and therapeutic applications. This study addresses the key principles and the most recent published data, focusing on monodisperse AuNP synthesis, surface modifications, and future theranostic applications. Moving forward, we also consider the possible development of functionalized monodisperse AuNPs for theranostic applications based on these efforts. We anticipate that as research advances, flexible AuNPs will become a crucial platform for medical applications.

Targeting Cancer Stem Cells: Therapeutic and diagnostic strategies by the virtue of nanoparticles

Cancer stem cells (CSCs) are the subpopulation of cells present within a tumor with the properties of self-renewing, differentiating, and proliferating. Owing to the presence of ATP-binding cassette drug pumps and increased expression of anti-apoptotic proteins, the conventional chemotherapeutic agents have failed to eliminate CSCs resulting in relapse and resistance of cancer. Therefore, to obtain long-lasting clinical responses and avoid the recurrence of cancer, it is crucial to develop an efficient strategy targeting CSCs by either employing a differentiation therapy or specifically delivering drugs to CSCs. Several intracellular and extracellular cancer specific biomarkers are overexpressed by CSCs and are utilized as targets for the development of new approaches in the diagnosis and treatment of CSCs. Moreover, several nanostructured particles, alone or in combination with current treatment approaches, have been used to improve the detection, imaging, and targeting of CSCs, thus addressing the limitations of cancer therapies. Targeting CSC surface markers, stemness-related signaling pathways, and tumor microenvironmental signals has improved the detection and eradication of CSCs and, therefore, tumor diagnosis and treatment. This review summarizes a variety of promising nanoparticles targeting the surface biomarkers of CSCs for the detection and eradication of tumor-initiating stem cells, used in combination with other treatment regimens.

Green synthesis and antibacterial applications of gold and silver nanoparticles from Ligustrum vulgare berries

Increasing demand for green or biological nanoparticles has led to various green technologies and resources, which play a critical role in forming biocompatible or green nanoparticles. So far, numerous medicinal plants have been explored for this purpose, assuming that medicinal components from the plant's material will contribute to corona formation around nanoparticles and enhance their efficacy. Research is also extended to other green and waste resources to be utilized for this purpose. In the current study, we explored Ligustrum vulgare berries, also known as privet berries, to reduce gold and silver salts into nanoparticles. L. vulgare berries showed great potential to form these nanoparticles, as gold nanoparticles (LV-AuNPs) formed within 5 min at room temperature, and silver nanoparticles (LV-AgNPs) formed in 15 min at 90 °C. LV-AuNPs and LV-AgNPs were characterized by various analytical methods, including UV–Vis, SEM, EDX, TEM, DLS, sp-ICP-MS, TGA, FT-IR, and MALDI-TOF. The results demonstrate that the LV-AuNPs are polydisperse in appearance with a size range 50–200 nm. LV-AuNPs exhibit various shapes, including spherical, triangular, hexagonal, rod, cuboid, etc. In contrast, LV-AgNPs are quite monodisperse, 20–70 nm, and most of the population was spherical. The nanoparticles remain stable over long periods and exhibit high negative zeta potential values. The antimicrobial investigation of LV-AgNPs demonstrated that the nanoparticles exhibit antibacterial ability with an MBC value of 150 g/mL against P. aeruginosa and 100 g/mL against E. coli, as determined by plate assay, live and dead staining, and SEM cell morphology analysis.

Mitochondria-Targeted, Nanoparticle-Based Drug-Delivery Systems: Therapeutics for Mitochondrial Disorders

Apart from ATP generation, mitochondria are involved in a wide range of functions, making them one of the most prominent organelles of the human cell. Mitochondrial dysfunction is involved in the pathophysiology of several diseases, such as cancer, neurodegenerative diseases, cardiovascular diseases, and metabolic disorders. This makes it a target for a variety of therapeutics for the diagnosis and treatment of these diseases. The use of nanoparticles to target mitochondria has significant importance in modern times because they provide promising ways to deliver drug payloads to the mitochondria by overcoming challenges, such as low solubility and poor bioavailability, and also resolve the issues of the poor biodistribution of drugs and pharmacokinetics with increased specificity. This review assesses nanoparticle-based drug-delivery systems, such as liposomes, DQAsome, MITO-Porters, micelles, polymeric and metal nanocarriers, as well as quantum dots, as mitochondria-targeted strategies and discusses them as a treatment for mitochondrial disorders.

In vivo bio-distribution and acute toxicity evaluation of greenly synthesized ultra-small gold nanoparticles with different biological activities

Ultra-small gold nanoparticles (Au-NPs) “≤ 10 nm diameters” have potent biomedical applications. Hence, the present study aimed to greenly synthesize ultra-small gold nanoparticles using Egyptian propolis extract. Different biological activities, in vivo bio-distribution and acute toxicity study were assessed. Results revealed that, Egyptian propolis extract can successfully synthesize the highly pure and stable ultra-small Au-NPs with average diameter 7.8 nm. In vitro antimicrobial and antimycobacterial activities revealed the powerful effect of the prepared Au-NPs. Moreover, the cytotoxic effect on human cancer cell lines revealed the potent inhibition of the cancer cells’ proliferation with high reactive oxygen species-mediated apoptosis induction. In vivo bio-distribution and acute toxicity studies were performed (10 and 100 mg/kg doses) in male albino rats. The ultra-small Au-NPs showed low or no toxicity upon using the Au-NPs low dose. The mean area accumulation (%) of the Au-NPs was higher in the liver, kidney, and brain tissues (4.41, 2.96, and 0.3 times, respectively) treated with high Au-NPs dosage compared to those treated with the low dose. Surprisingly, Au-NP accumulation in brain tissue was observed in the glial cells only. Accordingly, the low dose (10 mg/kg) of Au-NPs can be used safely in a variety of biomedical applications.

Emerging 2D materials for antimicrobial applications in the pre- and post-pandemic era

Infectious diseases caused by viral or bacterial pathogens are one of the most serious threats to humanity. Moreover, they may lead to pandemics, as we have witnessed severely with the coronavirus disease 2019 (COVID-19). Nanotechnology, including technological developments of nano-sized materials, has brought great opportunities to control the spreading of such diseases. In the family of nano-sized materials, two-dimensional (2D) materials with intrinsic physicochemical properties can efficiently favor antimicrobial activity and maintain a safer environment to protect people against pathogens. For this purpose, they can be used alone or combined for the disinfection process of microbes, antiviral or antibacterial surface coatings, air filtering of medical equipment like face masks, or antimicrobial drug delivery systems. At the same time, they are promising candidates to deal with the issues of conventional antimicrobial approaches such as low efficacy and high cost. This review covers the antiviral or antibacterial activities of 2D materials and highlights their current and possible future applications. Considering their intrinsic properties, 2D materials will become part of the leading antimicrobial technologies for combating future pandemics anytime soon.

Fast Generation of Machine Learning-Based Force Fields for Adsorption Energies

Adsorption and desorption of molecules are key processes in extraction and purification of biomolecules, engineering of drug carriers, and designing of surface-specific coatings. To understand the adsorption process on the atomic scale, state-of-the-art quantum mechanical and classical simulation methodologies are widely used. However, studying adsorption using a full quantum mechanical treatment is limited to picoseconds simulation timescales, while classical molecular dynamics simulations are limited by the accuracy of the existing force fields. To overcome these challenges, we propose a systematic way to generate flexible, application-specific highly accurate force fields by training artificial neural networks. As a proof of concept, we study the adsorption of the amino acid alanine on graphene and gold (111) surfaces and demonstrate the force field generation methodology in detail. We find that a molecule-specific force field with Lennard-Jones type two-body terms incorporating the 3rd and 7th power of the inverse distances between the atoms of the adsorbent and the surfaces yields optimal results, which is surprisingly different from typical Lennard-Jones potentials used in traditional force fields. Furthermore, we present an efficient and easy-to-train machine learning model that incorporates system-specific three-body (or higher order) interactions that are required, for example, for gold surfaces. Our final machine learning-based force field yields a mean absolute error of less than 4.2 kJ/mol at a speed-up of ∼10⁵ times compared to quantum mechanical calculation, which will have a significant impact on the study of adsorption in different research areas.

Polymeric Materials as Potential Inhibitors Against SARS-CoV-2

Recently discovered SARS-CoV-2 caused a pandemic that triggered researchers worldwide to focus their research on all aspects of this new peril to humanity. However, in the absence of specific therapeutic intervention, some preventive strategies and supportive treatment minimize the viral transmission as studied by some factors such as basic reproduction number, case fatality rate, and incubation period in the epidemiology of viral diseases. This review briefly discusses coronaviruses' life cycle of SARS-CoV-2 in a human host cell and preventive strategies at some selected source of infection. The antiviral activities of synthetic and natural polymers such as chitosan, hydrophobically modified chitosan, galactosylated chitosan, amine-based dendrimers, cyclodextrin, carrageenans, polyethyleneimine, nanoparticles are highlighted in this article. Mechanism of virus inhibition, detection and diagnosis are also presented. It also suggests that polymeric materials and nanoparticles can be effective as potential inhibitors and immunization against coronaviruses which would further develop new technologies in the field of polymer and nanoscience.

Urokinase Plasminogen Activator Receptor-Mediated Targeting of a Stable Nanocomplex Coupled with Specific Peptides for Imaging of Cancer

Targeting peptides are a promising tool for early diagnosis and therapy of cancer. Overexpression of urokinase plasminogen activator receptor (uPAR) leads to the progression of tumors including prostate, colorectal, ovarian, and breast cancers. To improve the diagnosis and imaging efficiency, herein we report a stable nanocomplex comprising methoxy-PEG-hydrazide (mPEG-H-M)-modified gold nanoparticles (AuNPs) conjugated to uPAR (urokinase plasminogen activator receptor)-targeting peptides GFD (growth factor domain-G) and SMB (somatomedian B-S) for efficient imaging of uPAR-overexpressing cancer cells. Fluorescently labeled targeting peptides were covalently linked to mPEG-H coated AuNPs, characterized, and analyzed by UV-vis spectroscopy, diffraction light scattering (DLS), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), and fluorescence spectroscopy. In vitro evaluation was assessed with a fluorescence-activated cell sorter (FACS), cell adhesion, and fluorescence microscopy. The peptide-functionalized nanocomplex showed a higher uptake of AuNPs@MGS in comparison with AuNPs@G or AuNPs@S alone in uPAR-overexpressing cells and exhibits no toxicity when analyzed with MTT assay. Our results demonstrated that the developed nanocomplex can be used as a platform for imaging and diagnosis of metastatic tumors.

EGFRvIII peptide nanocapsules and bevacizumab nanocapsules: a nose-to-brain multitarget approach against glioblastoma

Aim: To evaluate the antitumor efficacy of bevacizumab-functionalized nanocapsules in a rat glioblastoma model after the pretreatment with nanocapsules functionalized with a peptide-specific to the epidermal growth factor receptor variant III. Materials & methods: Nanocapsules were prepared, physicochemical characterized and intranasally administered to rats. Parameters such as tumor size, histopathological characteristics and infiltration of CD8⁺ T lymphocytes were evaluated. Results: The strategy of treatment resulted in a reduction of 87% in the tumor size compared with the control group and a higher infiltration of CD8⁺ T lymphocytes in tumoral tissue. Conclusion: The block of two different molecular targets using nose-to-brain delivery represents a new and promising approach against glioblastoma.

Modification of Metal-Organic Framework Nanoparticles Using Dental Pulp Mesenchymal Stem Cell Membranes to Target Oral Squamous Cell Carcinoma

Engineering a targetable nanoparticle to tumor cell is a challenge issue for clinical application. Our results demonstrated that the chemokine CXCL8 secreted by oral squamous cell carcinoma (OSCC) could act as a chemoattractant to attract dental pulp mesenchymal stem cell (DPSC), which expressed the CXCL8 binding receptor, CXCR2, to the OSCC. Therefore, to create OSCC targetable nanoparticles, we used DPSC membranes to modify nanoparticles of metal-organic framework nanoparticles (MOFs) resulting in a novel MOF@DPSCM nanoparticle. Interestingly, results from in vitro and in vivo experiments illustrated that MOF@DPSCM possessed specificity for the OSCC, and the MOF@DPSCM carried DOX (doxorubicin), MOF-DOX@DPSCM could induce CAL27 cell death in vitro and block CAL27 tumor growth in vivo. Our data suggest that this novel MOF-DOX@DPSCM nanoparticle is a potential targetable drug delivery system for the OSCC in the future clinical application.

Chitosan-Based Nanoparticles Against Viral Infections

Viral infections, in addition to damaging host cells, can compromise the host immune system, leading to frequent relapse or long-term persistence. Viruses have the capacity to destroy the host cell while liberating their own RNA or DNA in order to replicate within additional host cells. The viral life cycle makes it challenging to develop anti-viral drugs. Nanotechnology-based approaches have been suggested to deal effectively with viral diseases, and overcome some limitations of anti-viral drugs. Nanotechnology has enabled scientists to overcome the challenges of solubility and toxicity of anti-viral drugs, and can enhance their selectivity towards viruses and virally infected cells, while preserving healthy host cells. Chitosan is a naturally occurring polymer that has been used to construct nanoparticles (NPs), which are biocompatible, biodegradable, less toxic, easy to prepare, and can function as effective drug delivery systems (DDSs). Furthermore, chitosan is Generally Recognized as Safe (GRAS) by the US Food and Drug Administration (U.S. FDA). Chitosan NPs have been used in drug delivery by the oral, ocular, pulmonary, nasal, mucosal, buccal, or vaginal routes. They have also been studied for gene delivery, vaccine delivery, and advanced cancer therapy. Multiple lines of evidence suggest that chitosan NPs could be used as new therapeutic tools against viral infections. In this review we summarize reports concerning the therapeutic potential of chitosan NPs against various viral infections.

Biomedical applications of the peptide decorated gold nanoparticles

Currently, peptide-nanoparticle (NP) conjugates have been demonstrated to be efficient and powerful tools for the treatment and the diagnosis of various diseases as well as in the bioimaging application. Several bioconjugation strategies have been adopted to formulate the peptide-NP conjugates. In this review, we discuss the exciting applications of peptide-gold (Au) NP conjugates in the area of drug delivery, targeting, cancer therapy, brain diseases, vaccines, immune modulation, biosensor, colorimetric detection of heavy metals, and bio-labeling in vitro and in vivo models. Within this framework, various approaches such as radiotherapy, photothermal therapy, photodynamic therapy and chemo-photothermal therapy have been demonstrated for the treatment of several diseases. Moreover, we highlight how the morphology, size, density of peptide and the protein corona influence the biological activity, biodistribution and biological fate of peptide-AuNP conjugates. In the end, we discuss the future outlook and the challenges being faced in the clinical translation of the peptide-AuNP conjugates. Overall, this review emphasizes that the peptide-AuNP conjugates might be used as potential theranostic agents for the treatment of life-threatening diseases in an economical fashion in the future.

Pickering emulsions stabilized by some inorganic materials

The paper presents studies of various solid stabilizers of emulsions based on inorganic materials. Inorganic colloidal particles have an advantage for obtaining of stable emulsions due to their safety for use in food, cosmetics, pharmaceutical industry and medicine. Pickering emulsions have a higher biodegradability compared to classical emulsions stabilized with surfactants. An overview of inorganic substances such as silicon dioxide, clay materials, metal and metal oxide nanoparticles, calcium compounds and carbon particles used for stabilizing of Pickering emulsions is considered. A variety of solid inorganic particles as well as modification of their surfaces by surfactants allows to obtain the stable Pickering emulsions of different types for a wide range of applications. It should be noted that despite a large number of studies, this class of disperse systems is still not studied fully; various methods of their preparation and influence of solid particle size on stability and size of emulsions droplets are shown.

Ultrastable PEGylated Calixarene-Coated Gold Nanoparticles with a Tunable Bioconjugation Density for Biosensing Applications

Many in vivo and in vitro applications using gold nanoparticles (AuNPs) require (i) their PEGylation, as it increases their stability and prevents nonspecific protein adsorption, and (ii) their conjugation to biomolecules, that provides them with specific recognition properties. Currently, the functionalization of AuNPs is based on thiol chemistry that suffers from two major drawbacks: (i) the Au-S bond is labile and confers limited chemical robustness to the organic layer, and (ii) control over the bioconjugation density is highly challenging. We report here a novel functionalization strategy based on calix[4]arene-tetradiazonium platforms for the coating of AuNPs with a robust PEG layer and their controlled bioconjugation. AuNPs were first modified with a functional calix[4]arene-diazonium salt bearing three PEG chains ended by a methoxy group and one by a carboxyl group. The resulting particles showed excellent chemical and colloidal stabilities, compared to similar systems obtained via a classical thiol chemistry, and could even be dispersed in human serum without degrading or aggregating. In addition to that, the carboxyl groups protruding from the PEG layer allowed their conjugation via amide bond formation with amine-containing biomolecules such as peptides. The control of the bioconjugation was obtained by grafting mixed layers of functional and nonfunctional PEGylated calix[4]arenes, that allowed varying the number of functional groups carried by the AuNPs and subsequently their bioconjugation capacity while preserving their dense protective PEG shell. Finally, we used these nanomaterials, modified with peptide aptamers, for the in vitro biosensing of a cancer biomarker, Mdm2.

Recent Strategies and Applications for l-Asparaginase Confinement

l-asparaginase (ASNase, EC 3.5.1.1) is an aminohydrolase enzyme with important uses in the therapeutic/pharmaceutical and food industries. Its main applications are as an anticancer drug, mostly for acute lymphoblastic leukaemia (ALL) treatment, and in acrylamide reduction when starch-rich foods are cooked at temperatures above 100 °C. Its use as a biosensor for asparagine in both industries has also been reported. However, there are certain challenges associated with ASNase applications. Depending on the ASNase source, the major challenges of its pharmaceutical application are the hypersensitivity reactions that it causes in ALL patients and its short half-life and fast plasma clearance in the blood system by native proteases. In addition, ASNase is generally unstable and it is a thermolabile enzyme, which also hinders its application in the food sector. These drawbacks have been overcome by the ASNase confinement in different (nano)materials through distinct techniques, such as physical adsorption, covalent attachment and entrapment. Overall, this review describes the most recent strategies reported for ASNase confinement in numerous (nano)materials, highlighting its improved properties, especially specificity, half-life enhancement and thermal and operational stability improvement, allowing its reuse, increased proteolysis resistance and immunogenicity elimination. The most recent applications of confined ASNase in nanomaterials are reviewed for the first time, simultaneously providing prospects in the described fields of application.

Photo-irradiation coupled biosynthesis of magnesium oxide nanoparticles for antibacterial application

In recent times, magnesium oxide (MgO) nanoparticles are proven to be an excellent antibacterial agent which inhibits the growth of bacteria by generating reactive oxygen species (ROS). Release of ROS by nanoparticles will damage the cell membrane of bacteria and leads to the leakage of bacterial internal components and cell death. However, chemically synthesized MgO nanoparticles may possess toxic functional groups which may inhibit healthy human cells along with bacterial cells. Thus, the aim of the present study is to synthesize MgO nanoparticles using leaf extracts of Amaranthus tricolor and photo-irradiation of visible light as a catalyst, without addition of any chemicals. Optimization was performed using Box-Behnken design (BBD) to obtain the optimum condition required to synthesize smallest nanoparticles. The parameters such as time of reaction, the concentration of precursor, and light intensity have been identified to affect the size of biosynthesized nanoparticles and was optimized. The experiment performed with optimized conditions such as 0.001 M concentration of magnesium acetate as precursor, 5 cm distance of light (intensity), and 15 min of reaction time (light exposure) has led to the formation of 74.6 nm sized MgO nanoparticles. The antibacterial activities of MgO nanoparticles formed via photo-irradiation and conventional biosynthesis approach were investigated and compared. The lethal dosage of E. coli for photo-irradiated and conventional biosynthesis MgO nanoparticles was 0.6 ml and 0.4 ml, respectively. Likewise, the lethal dosage of S. aureus for both biosynthesis approaches was found to be 0.4 ml. The results revealed that the antibacterial activity of MgO nanoparticles from both biosynthesis approaches was similar. Thus, photo-irradiated MgO nanoparticles were beneficial over heat-mediated conventional method due to the reduced synthesis duration.

5-Fluorouracil Loaded Biogenic and Albumin Capped Gold Nanoparticles Using Bacterial Enzyme—In Vitro-In Silico Gastroplus® Simulation and Prediction

The study investigated in situ biosynthesis of albumin capped 5-fluorouracil (5-FU) loaded gold nanoparticles (NPs) using bacterial extract for enhanced efficacy against MCF-7 and in silico prediction using a GastroPlus® software. The optimized formulations were characterized for morphology, size, zeta potential, drug loading (%DL) and entrapment (%EE), compatibility, in vitro drug release, in vitro hemolysis, cellular toxicity and apoptosis studies. The results exhibited highly dispersed albumin capped mono-metallic stable NPs. Spherical size, negative zeta potential and polydispersity index were in range of 38.25–249.62 nm, 18.18–29.87 mV and 0.11–0.283, respectively. F11, F7 and F3 showed a progressive increase in %DL and %EE with increased concentration of the cellular lysate (100% > 50% > 10%). The drug release was relatively extended over 48 h as compared to drug solution (96.64% release within 5 h). The hemolysis result ensured hemocompatibility (<14%) at the explored concentration. The biogenic F11 was more cytotoxic (81.99% inhibition by F11 and 72.04% by pure 5-FU) to the MCF-7 cell lines as compared to others which may be attributed to the preferential accumulation by the tumor cell and capped albumin as the source of energy to the cancer cells. Finally, GastroPlus® predicted the key factors responsible for improved pharmacokinetics parameters and regional absorption from various segments of human intestine. Thus, the approach can be more efficacious and suitable to control breast cancer when administered transdermally or orally.

Targeting arachidonic acid-related metabolites in COVID-19 patients: potential use of drug-loaded nanoparticles

In March 2020, The World Health Organization (WHO) has declared that the coronavirus disease 2019 (COVID-19) is characterized as a global pandemic. As of September 2020, infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread to 213 countries and territories around the world, affected more than 31.5 million people, and caused more than 970,000 deaths worldwide. Although COVID-19 is a respiratory illness that mainly targets the lungs, it is currently well established that it is a multifactorial disease that affects other extra-pulmonary systems and strongly associated with a detrimental inflammatory response. Evidence has shown that SARS-CoV-2 causes perturbation in the arachidonic acid (AA) metabolic pathways; this disruption could lead to an imbalance between the pro-inflammatory metabolites of AA including mid-chain HETEs and terminal HETE (20-HETE) and the anti-inflammatory metabolites such as EETs and subterminal HETEs. Therefore, we propose novel therapeutic strategies to modulate the level of endogenous anti-inflammatory metabolites of AA and induce the patient's endogenous resolution mechanisms that will ameliorate the virus-associated systemic inflammation and enhance the primary outcomes in COVID-19 patients. Also, we propose that using nanoencapsulation of AA and its associated metabolites will contribute to the development of safer and more efficacious treatments for the management of COVID-19.

Enhanced cytotoxicity of highly water-soluble gold nanoparticle-cyclopeptide conjugates in cancer cells

Conjugation of cytostatic drugs to nanomaterials seeks to improve their low bioavailability and selectivity to overcome the important associated side effects. In this work, we aimed to synthesize water-soluble gold nanoparticles as transporters for synthetic cyclic peptides with a potential anticancer activity but with a limited bioavailability. The highly water-soluble nanoparticles (2.5 nm diameter gold core) are coated with a mixture of polyethylene glycol linkers, one bearing a terminal hydroxyl group for increasing dispersibility in water, and the second bearing a carboxylic acid group for peptide conjugation through amide bond formation. Peptide-functionalized particles have a 9.7 ± 1.8 nm hydrodynamic diameter and are highly water-soluble and stable in solution for at least one year. The morphology of the gold cores as well as their organic coating was studied using Transmission Electron Microscopy, showing that the attachment of a limited number of peptides per nanoparticle leads to a uneven organic coating of two different thicknesses, one of 2.0 ± 0.6 nm formed by polyethylene glycol linkers, and a second of 3.6 ± 0.5 nm which includes the peptide. GNP significantly enhance the internalization of the cyclic peptide BPC734 in cells as compared to peptide in solution, with improved uptake in cancerous HT29 cells. Cytotoxicity studies show that peptide BPC734 in solution is toxic in the micromolar range, whereas peptide-functionalized particles are toxic at nanomolar peptide concentrations and with a significantly higher toxicity for cancerous cells. All these results, besides the stability and expected passive tumor targeting, make these particles a promising option for improving the bioavailability, efficacy, and selectivity in cancer therapy.

Active targeting of gold nanoparticles as cancer therapeutics

Gold nanoparticles (AuNPs) are of increasing interest for their unique properties and their biocompatability, minimal toxicity, multivalency and size tunability make them exciting drug carriers. The functionalisaton of AuNPs with targeting moieties allows for their selective delivery to cancers, with antibodies, proteins, peptides, aptamers, carbohydrates and small molecules all exploited. Here, we review the recent advances in targeted-AuNPs for the treatment of cancer, with a particular focus on these classes of targeting ligands. We highlight the benefits and potential drawbacks of each ligand class and propose directions in which the field could grow.

Tailoring Viruslike Mesoporous FeSe2 Hedgehogs for Controlled Drug Delivery and Synergistic Tumor Suppression

To enhance affinity to their hosts, many organisms have evolved to be spiky. This strategy has been inspiring in many fields, but in drug delivery, the feasibility has not yet been extensively explored due to the lack of suitable nanocarriers. Herein, viruslike mesoporous FeSe₂ hedgehogs with exceptional photothermal and catalytic performances have been tailored and explored for synergistic tumor therapy. The viruslike topology makes these hedgehogs highly prone to be internalized by cells. By uploading doxorubicin (Dox) into the hollow spikes and encapsulating the hedgehogs with photothermal-meltable gelatin, controlled surface morphology transition from quasi-spherical to spiky and accompanied Dox release have been achieved, with the assistance of the strong photothermal effect of FeSe₂ hedgehogs. These integrated features allow specific and controlled drug delivery, leading to synergistic tumor suppression and immunogenic tumor cell death. These results provide new insights into the tailoring of drug carriers relying on their intrinsic physical features.

Stimuli-responsive and cellular targeted nanoplatforms for multimodal therapy of skin cancer

Interdisciplinary applications of nanopharmaceutical sciences have tremendous potential for enhancing pharmacokinetics, efficacy and safety of cancer therapy. The limitations of conventional therapeutic platforms used for skin cancer therapy have been largely overcome by the use of nanoplatforms. This review discusses various nanotechnological approaches experimented for the treatment of skin cancer. The review describes various polymeric, lipidic and inorganic nanoplatforms for efficient therapy of skin cancer. The stimuli-responsive nanoplatforms such as pH-responsive as well as temperature-responsive platforms have also been reviewed. Different strategies for potentiating the nanoparticles application for cancer therapy such as surface engineering, conjugation with drugs, stimulus-responsive and multimodal effect have also been discussed and compared with the available conventional treatments. Although, nanopharmaceuticals face challenges such as toxicity, cost and scale-up, efforts put-in to improve these drawbacks with continuous research would deliver exciting and promising results in coming days.

Role of Free Thiol on Protein Adsorption to Gold Nanoparticles

Protein-gold nanoparticle (AuNP) bioconjugates have many potential applications in nanomedicine. A thorough understanding of the interaction between the protein and the AuNP is critical to engineering these functional bioconjugates with desirable properties. In this work, we investigate the role of free thiols presented by the protein on the stability of the protein-AuNP conjugate. Human serum albumin (HSA) was modified with 2-iminothiolane (Traut's reagent) to introduce additional thiols onto the protein surface, and three variants of HSA were synthesized to present 1, 5, and 20 free thiols by controlling the molar excess of the chemical modifier. Protein exchange studies on AuNPs were conducted using these HSA species and an IgG antibody which exhibited 10 free thiols. Antibody-AuNP conjugates were synthesized, purified, and dispersed in solutions containing each of the HSA species. No protein exchange was detected with the HSA or modified HSA containing 5 thiols; however, 85% of the antibody was displaced on the AuNP surface by the extensively thiolated HSA presenting 20 free thiols. Furthermore, the impact of the protein adsorption sequence was probed in which each of the HSA species were preadsorbed onto the AuNP and dispersed in a solution of antibody. The antibody fully displaced the HSA with a single thiol from the AuNP within 3 h, required 24 h to completely displace the modified HSA containing 5 thiols, and was unable to displace the modified HSA containing 20 thiols. These results indicate that the number of Au-S interactions governs the binding interaction between the protein and the AuNP. This work provides further insight into the protein-AuNP binding mechanism and identifies important design principles for engineered proteins to optimize bioconjugates.

Trastuzumab and folic acid functionalized gold nanoclusters as a dual-targeted radiosensitizer for megavoltage radiation therapy of human breast cancer

In the present study, the effect of functionalized gold nanoclusters (AuNCs) with trastuzumab (Herceptin®) and/or folic acid (FA) as a single and dual-targeted radiosensitizers for the enhancement of megavoltage radiation therapy efficacy was investigated. SK-BR3 breast cancer cells as human epidermal growth factor 2 (HER2) and folate overexpressing cell line and the murine fibroblast (L929) as a control cell line were selected. The cellular uptake was followed using inductively coupled plasma optical emission spectrometry (ICP-OES) that showed AuNCs-FA-HER uptake by SK-BR3 cells was 3 times more than the non-targeted AuNCs after 12 h incubation. MTT and clonogenic assays revealed that the viability and surviving fraction of cancer cells were significantly inhibited by treating with all AuNCs under radiation compared to treating with radiation alone. However, these effects in the dual-targeted AuNCs group (AuNCs-FA-HER) was significantly greater than non-targeted and single-targeted AuNCs groups. Also, apoptosis was evaluated using an Annexin V-FITC/propidium iodide (PI) kit in flow cytometry. All AuNCs, in combination with 4 Gy of photon beam, induced more apoptosis. By fitting the survival fraction data on the linear-quadratic model, the sensitization enhancement factor (SER) of AuNCs, AuNCs-FA, AuNCs-HER, and AuNCs-FA-HER, were obtained 1.17, 1.32, 1.48 and 1.77, respectively. SER for AuNCs-FA-HER was significantly higher than that non-targeted and single-targeted AuNCs (p-value < 0.05) that can be attributed to more internalization in the cancer cells. It was concluded that functionalized AuNCs with both folic acid and Herceptin could represent a promising strategy for increased cellular internalization that improved radiation therapy efficiency in SK-BR3 breast cancer cells.

Anlar G, A. Hussein E, Elzatahry A, C. Yalcin H. Effect of Flow-Induced Shear Stress in Nanomaterial Uptake by Cells: Focus on Targeted Anti-Cancer Therapy

Recently, nanomedicines have gained a great deal of attention in diverse biomedical applications, including anti-cancer therapy. Being different from normal tissue, the biophysical microenvironment of tumor cells and cancer cell mechanics should be considered for the development of nanostructures as anti-cancer agents. Throughout the last decades, many efforts devoted to investigating the distinct cancer environment and understanding the interactions between tumor cells and have been applied bio-nanomaterials. This review highlights the microenvironment of cancer cells and how it is different from that of healthy tissue. We gave special emphasis to the physiological shear stresses existing in the cancerous surroundings, since these stresses have a profound effect on cancer cell/nanoparticle interaction. Finally, this study reviews relevant examples of investigations aimed at clarifying the cellular nanoparticle uptake behavior under both static and dynamic conditions.

Resurrecting a p53 peptide activator - An enabling nanoengineering strategy for peptide therapeutics

Many high-affinity peptide antagonists of MDM2 and MDMX have been reported as activators of the tumor suppressor protein p53 with therapeutic potential. Unfortunately, peptide activators of p53 generally suffer poor proteolytic stability and low membrane permeability, posing a major pharmacological challenge to anticancer peptide drug development. We previously obtained several potent dodecameric peptide antagonists of MDM2 and MDMX termed PMIs, one of which, TSFAEYWALLSP, bound to MDM2 and MDMX at respective affinities of 0.49 and 2.4 nM. Here we report the development of gold nanoparticles (Np) as a membrane-traversing delivery vehicle to carry PMI for anticancer therapy. Np-PMI was substantially more active in vitro than Nutlin-3 in killing tumor cells bearing wild-type p53, and effectively inhibited tumor growth in metastasis in a mouse homograft mode of melanoma and a patient-derived xenograft model of colon cancer with a favorable safety profile. This clinically viable drug delivery strategy can be applied not only to peptide activators of p53 for cancer therapy, but also to peptide therapeutics in general aimed at targeting intracellular protein-protein interactions for disease intervention.

A general-purpose Nanohybrid fabricated by Polymeric Au(I)-peptide precursor to wake the function of Peptide Therapeutics

Peptide-derived nanocomposites have been exhibiting fascinating biological advantages, including but not limited to excellent biocompatibility, biological degradation, high targetability and subsequent potent therapeutic efficacy. While some successes have been achieved in the nanoengineering of peptide-based architectures with defined dimensions and medical functions, enormous challenges remain about clinical nano-pharmaceutics of peptides, especially those modulating intracellular protein-protein interactions (PPIs). Methods: We developed a general method to translate intracellular-PPI-targeted peptides into a bioavailable peptide-auric spheroidal nanohybrid (SNH), for which polymeric peptide-Auric precursors [Au1+-S-peptide]n are in-situ reduced on the surface of gold nanoseeds via a simple and mild reaction. As proofs of concept, three cytomembrane-impenetrable peptides with different physicochemical properties were successfully engineered into stable and tumor-specific SNH respectively. Results: To highlight the advantage of SNH, PMI, a hydrophobic and enzyme-intolerant peptide capable of p53 restoration, was selected to challenge the power of SNH in a colon tumor xenografts model. PMI-Au SNH in vivo suppressed tumor growth potently after three administrations: intravenous injection, intraperitoneal injection and gastric perfusion, and maintained a favorable therapeutic safety. Conclusion: This therapeutically feasible strategy of peptide nanoengineering will allow us to fabricate a series of nanomedicines to modulate carcinogenic PPIs that hide and multiply inside cells, and in all likelihood reinvigorate the development of peptide drug against wide varieties of human diseases.

Delivery of drugs, proteins, and nucleic acids using inorganic nanoparticles

Inorganic nanoparticles provide multipurpose platforms for a broad range of delivery applications. Intrinsic nanoscopic properties provide access to unique magnetic and optical properties. Equally importantly, the structural and functional diversity of gold, silica, iron oxide, and lanthanide-based nanocarriers provide unrivalled control of nanostructural properties for effective transport of therapeutic cargos, overcoming biobarriers on the cellular and organismal level. Taken together, inorganic nanoparticles provide a key addition to the arsenal of delivery vectors for fighting disease and improving human health.