Surface and size effects on cell interaction of gold nanoparticles with both phagocytic and nonphagocytic cells

Effects of nanoparticle size, shape, and zeta potential on drug delivery

Nanotechnology has brought about a significant revolution in drug delivery, and research in this domain is increasingly focusing on understanding the role of nanoparticle (NP) characteristics in drug delivery efficiency. First and foremost, we center our attention on the size of nanoparticles. Studies have indicated that NP size significantly influences factors such as circulation time, targeting capabilities, and cellular uptake. Secondly, we examine the significance of nanoparticle shape. Various studies suggest that NPs of different shapes affect cellular uptake mechanisms and offer potential advantages in directing drug delivery. For instance, cylindrical or needle-like NPs may facilitate better cellular uptake compared to spherical NPs. Lastly, we address the importance of nanoparticle charge. Zeta potential can impact the targeting and cellular uptake of NPs. Positively charged NPs may be better absorbed by negatively charged cells, whereas negatively charged NPs might perform more effectively in positively charged cells. This review provides essential insights into understanding the role of nanoparticles in drug delivery. The properties of nanoparticles, including size, shape, and charge, should be taken into consideration in the rational design of drug delivery systems, as optimizing these characteristics can contribute to more efficient targeting of drugs to the desired tissues. Thus, research into nanoparticle properties will continue to play a crucial role in the future of drug delivery.

Unveiling the theranostic potential of SPIONs in Alzheimer's disease management

Alzheimer's disease (AD) is a devastating kind of dementia that is becoming more common worldwide. Toxic amyloid-beta (Aβ) aggregates are the primary cause of AD onset and development. Superparamagnetic iron oxide nanoparticles (SPIONs) have received a lot of interest in AD therapy over the last decade because of their ability to redirect the Aβ fibrillation process and improve associated brain dysfunction. The potential diagnostic application of SPIONs in AD has dramatically increased this interest. Furthermore, surface-modified engineered SPIONs function as drug carriers to improve the efficacy of current therapies. Various preclinical and clinical studies on the role of SPIONs in AD pathology have produced encouraging results. However, due to their physicochemical properties (e.g., size, surface charge, and particle concentration) in the biological milieu, SPIONs may play the role of a preventive or accelerative agent in AD. Even though SPIONs are potential therapeutic and diagnostic options in AD, significant efforts are still needed to overcome the inconsistencies and safety concerns. This review evaluated the current understanding of how various SPIONs interact with AD models and explored the discrepancies in their efficacy and safety.

pH-responsive chitosan copolymer synthesized via click chemistry for design of polymeric nanoparticles for targeted drug delivery

The polymeric nanoparticles (PNPs) loaded with prednisolone were developed to exhibit pH-responsive properties owing to the attachment of a hydrazone linkage between the copolymer chitosan and mPEG. In the diseased cellular environment, the hydrazone bond tends to break due to reduced pH, leading to the release of the drug from the PNPs at the required site of action. The fabricated PNPs exhibit spherical morphology, optimum size (∼200 nm), negative surface charge, and monodispersed particle size distribution. The encapsulation efficiency of the PNPs was determined to be 71.1 ± 0.79 % and two experiments (polymer weight loss and drug release) confirmed the pH-responsive properties of the PNPs. The cellular study cytotoxicity assay showed biocompatibility of PNPs and drug molecule-mediated toxicity to A549 cells. The ligand atrial natriuretic peptide-attached PNPs internalized into A549 cells via natriuretic peptide receptor-A to achieve target specificity. The PNPs cytotoxicity and pH-response medicated inflammation reduction functionality was studied in inflammation-induced RAW264.7 cell lines. The study observed the PNPs effectively reduced the inflammatory mediators NO and ROS levels in RAW264.7. The results showed that pH-responsive properties of PNPs and this novel fabricated delivery system effectively treat inflammatory and cancer diseases.

Advanced protein-embedded bimetallic nanocomposite optimized for in vivo fluorescence and magnetic resonance bimodal imaging

HYPOTHESIS

The development of bimodal imaging probes represents a hot topic of current research. Herein, we deal with developing an innovative bimodal contrast agent enabling fluorescence imaging (FI)/magnetic resonance imaging (MRI) and, simultaneously, consisting of biocompatible nanostructures. Optimized synthesis of advanced protein-embedded bimetallic (APEBM) nanocomposite containing luminescent gold nanoclusters (AuNC) and superparamagnetic iron oxide nanoparticles (SPION), suitable for in vivo dual-modal FI/MR imaging is reported.

EXPERIMENTS

The APEBM nanocomposite was prepared by a specific sequential one-pot green synthetic approach that is optimized to increase metals (Au, Fe) content and, consequently, the imaging ability of the resulting nanostructures. The protein matrix, represented by serum albumin, was intentionally chosen, and used since it creates an efficient protein corona for both types of optically/magnetically-susceptible nanostructures (AuNC, SPION) and ensures biocompatibility of the resulting APEBM nanocomposite although it contains elevated metal concentrations (approx. 1 mg·mL-1 of Au, around 0.3 mg·mL-1 of Fe). In vitro and in vivo imaging was performed.

FINDINGS

Successful in vivo FI and MRI recorded in healthy mice corroborated the applicability of the APEBM nanocomposite and, simultaneously, served as a proof of concept concerning the potential future exploitation of this new FI/MRI bimodal contrast agent in preclinical and clinical practice.

Receptor Targeting Using Copolymer-Modified Gold Nanoparticles for pCMV-Luc Gene Delivery to Liver Cancer Cells In Vitro

The formulation of novel delivery protocols for the targeted delivery of genes into hepatocytes by receptor mediation is important for the treatment of liver-specific disorders, including cancer. Non-viral delivery methods have been extensively studied for gene therapy. Gold nanoparticles (AuNPs) have gained attention in nanomedicine due to their biocompatibility. In this study, AuNPs were synthesized and coated with polymers: chitosan (CS), and polyethylene glycol (PEG). The targeting moiety, lactobionic acid (LA), was added for hepatocyte-specific delivery. Physicochemical characterization revealed that all nano-formulations were spherical and monodispersed, with hydrodynamic sizes between 70 and 250 nm. Nanocomplexes with pCMV-Luc DNA (pDNA) confirmed that the NPs could bind, compact, and protect the pDNA from nuclease degradation. Cytotoxicity studies revealed that the AuNPs were well tolerated (cell viabilities > 70%) in human hepatocellular carcinoma (HepG2), embryonic kidney (HEK293), and colorectal adenocarcinoma (Caco-2) cells, with enhanced transgene activity in all cells. The inclusion of LA in the NP formulation was notable in the HepG2 cells, which overexpress the asialoglycoprotein receptor on their cell surface. A five-fold increase in luciferase gene expression was evident for the LA-targeted AuNPs compared to the non-targeted AuNPs. These AuNPs have shown potential as safe and suitable targeted delivery vehicles for liver-directed gene therapy.

Gallic Acid-Modified Polyethylenimine-Polypropylene Carbonate-Polyethylenimine Nanoparticles: Synthesis, Characterization, and Anti-Periodontitis Evaluation

The aim of the research was to develop novel gallic acid (GA)-modified amphiphilic nanoparticles of polyethylenimine (PEI)-polypropylene carbonate (PPC)-PEI (PEPE) and comprehensively assess its properties as an antiperiodontitis nanoparticle targeting the Toll-like receptor (TLR). The first step is to evaluate the binding potential of GA to the core trigger receptors TLR2 and TLR4/MD2 for periodontitis using molecular docking techniques. Following this, we conducted NMR, transmission electron microscopy, and dynamic light scattering analyses on the synthesized PEPE nanoparticles. As the final step, we investigated the synthetic results and in vitro antiperiodontitis properties of GA-PEPE nanoparticles. The investigation revealed that GA exhibits potential for targeted binding to TLR2 and the TLR4/MD2 complex. Furthermore, we successfully developed 91.19 nm positively charged PEPE nanoparticles. Spectroscopic analysis indicated the successful synthesis of GA-modified PEPE. Additionally, CCK8 results demonstrated that GA modification significantly reduced the biotoxicity of PEPE. The in vitro antiperiodontitis properties assessment illustrated that 6.25 μM of GA-PEPE nanoparticles significantly reduced the expression of pro-inflammatory factors TNF-α, IL-1β, and IL-6. The GA-PEPE nanoparticles, with their targeted TLR binding capabilities, were found to possess excellent biocompatibility and antiperiodontitis properties. GA-PEPE nanoparticles will provide highly innovative input into the development of anti- periodontitis nanoparticles.

Cancer Cell Targeting Via Selective Transferrin Receptor Labeling Using Protein-Derived Carbon Dots

Carbon dot (CD) nanoparticles offer tremendous advantages as fluorescent probes in bioimaging and biosensing; however, they lack specific affinity for biomolecules, limiting their practical applications in selective targeting. Nanoparticles with intrinsic affinity for a target have applications in imaging, cytometry, therapeutics, etc. Toward that end, we report the transferrin receptor (CD71) targeting CDs, synthesized for the first time. The formation of these particles is truly groundbreaking, as direct tuning of nanoparticle affinity was achieved by simple and careful precursor selection of a protein, which has the targeting characteristic of interest. We hypothesized that the retention of the original protein's peptides on the nanoparticle surface provides the CDs with some of the function of the precursor protein, enabling selective binding to the protein's receptor. This was confirmed with FTIR (Fourier transform infrared) data and subsequent affinity-based cell assays. These transferrin (Tf)-derived CDs have been shown to possess an affinity for CD71, a cancer biomarker that is ubiquitously expressed in nearly every cancer cell line due to its central role mediating the uptake of cellular iron. The CDs were tested using the human leukemia cell line HL60 and demonstrated the selective targeting of CD71 and specific triggering of transferrin-mediated endocytosis via clathrin-coated pits. The particle characterization results reflect a carbon-based nanoparticle with bright violet fluorescence and 7.9% quantum yield in aqueous solution. These unpresented CDs proved to retain the functional properties of the precursor protein. Indicating that this process can be repeated for other disease biomarkers for applications ranging from biosensing and diagnostic bioimaging to targeted therapeutics.

Intracellular Trafficking of Size-Tuned Nanoparticles for Drug Delivery

Polymeric nanoparticles (NPs) are widely used as drug delivery systems in nanomedicine. Despite their widespread application, a comprehensive understanding of their intracellular trafficking remains elusive. In the present study, we focused on exploring the impact of a 20 nm difference in size on NP performance, including drug delivery capabilities and intracellular trafficking. For that, poly(ethylene glycol) methyl ether-block-poly(lactide-co-glycolide) (PLGA-PEG) NPs with sizes of 50 and 70 nm were precisely tailored. To assess their prowess in encapsulating and releasing therapeutic agents, we have employed doxorubicin (Dox), a well-established anticancer drug widely utilized in clinical settings, as a model drug. Then, the beneficial effect of the developed nanoformulations was evaluated in breast cancer cells. Finally, we performed a semiquantitative analysis of both NPs' uptake and intracellular localization by immunostaining lysosomes, early endosomes, and recycling endosomes. The results show that the smaller NPs (50 nm) were able to reduce the metabolic activity of cancer cells more efficiently than NPs of 70 nm, in a time and concentration-dependent manner. These findings are corroborated by intracellular trafficking studies that reveal an earlier and higher uptake of NPs, with 50 nm compared to the 70 nm ones, by the breast cancer cells. Consequently, this study demonstrates that NP size, even in small increments, has an important impact on their therapeutic effect.

Advancements in Macrophage-Targeted Drug Delivery for Effective Disease Management

Macrophages play a crucial role in tissue homeostasis and the innate immune system. They perform essential functions such as presenting antigens, regulating cytokines, and responding to inflammation. However, in diseases like cancer, cardiovascular disorders, and autoimmune conditions, macrophages undergo aberrant polarization, which disrupts tissue regulation and impairs their normal behavior. To address these challenges, there has been growing interest in developing customized targeted drug delivery systems specifically designed for macrophage-related functions in different anatomical locations. Nanomedicine, utilizing nanoscale drug systems, offers numerous advantages including improved stability, enhanced pharmacokinetics, controlled release kinetics, and precise temporal drug delivery. These advantages hold significant promise in achieving heightened therapeutic efficacy, specificity, and reduced side effects in drug delivery and treatment approaches. This review aims to explore the roles of macrophages in major diseases and present an overview of current strategies employed in targeted drug delivery to macrophages. Additionally, this article critically evaluates the design of macrophage-targeted delivery systems, highlighting limitations and discussing prospects in this rapidly evolving field. By assessing the strengths and weaknesses of existing approaches, we can identify areas for improvement and refinement in macrophage-targeted drug delivery.

Nanovaccines: A game changing approach in the fight against infectious diseases

The field of nanotechnology has revolutionised global attempts to prevent, treat, and eradicate infectious diseases in the foreseen future. Nanovaccines have proven to be a valuable pawn in this novel technology. Nanovaccines are made up of nanoparticles that are associated with or prepared with components that can stimulate the host's immune system. In addition to their delivery capabilities, the nanocarriers have been demonstrated to possess intrinsic adjuvant properties, working as immune cell stimulators. Thus, nanovaccines have the potential to promote rapid as well as long-lasting humoral and cellular immunity. The nanovaccines have several possible benefits, including site-specific antigen delivery, increased antigen bioavailability, and a diminished adverse effect profile. To avail these benefits, several nanoparticle-based vaccines are being developed, including virus-like particles, liposomes, polymeric nanoparticles, nanogels, lipid nanoparticles, emulsion vaccines, exomes, and inorganic nanoparticles. Inspired by their distinctive properties, researchers are working on the development of nanovaccines for a variety of applications, such as cancer immunotherapy and infectious diseases. Although a few challenges still need to be overcome, such as modulation of the nanoparticle pharmacokinetics to avoid rapid elimination from the bloodstream by the reticuloendothelial system, The future prospects of this technology are also assuring, with multiple options such as personalised vaccines, needle-free formulations, and combination nanovaccines with several promising candidates.

Bio-Inspired Nanomaterials for Micro/Nanodevices: A New Era in Biomedical Applications

Exploring bio-inspired nanomaterials (BINMs) and incorporating them into micro/nanodevices represent a significant development in biomedical applications. Nanomaterials, engineered to imitate biological structures and processes, exhibit distinctive attributes such as exceptional biocompatibility, multifunctionality, and unparalleled versatility. The utilization of BINMs demonstrates significant potential in diverse domains of biomedical micro/nanodevices, encompassing biosensors, targeted drug delivery systems, and advanced tissue engineering constructs. This article thoroughly examines the development and distinctive attributes of various BINMs, including those originating from proteins, DNA, and biomimetic polymers. Significant attention is directed toward incorporating these entities into micro/nanodevices and the subsequent biomedical ramifications that arise. This review explores biomimicry's structure-function correlations. Synthesis mosaics include bioprocesses, biomolecules, and natural structures. These nanomaterials' interfaces use biomimetic functionalization and geometric adaptations, transforming drug delivery, nanobiosensing, bio-inspired organ-on-chip systems, cancer-on-chip models, wound healing dressing mats, and antimicrobial surfaces. It provides an in-depth analysis of the existing challenges and proposes prospective strategies to improve the efficiency, performance, and reliability of these devices. Furthermore, this study offers a forward-thinking viewpoint highlighting potential avenues for future exploration and advancement. The objective is to effectively utilize and maximize the application of BINMs in the progression of biomedical micro/nanodevices, thereby propelling this rapidly developing field toward its promising future.

2D MoS2 Nanosheets Induce Ferroptosis by Promoting NCOA4-Dependent Ferritinophagy and Inhibiting Ferroportin

The exposure of MoS₂ nanosheets can cause cytotoxicity, which causes health risks and affects its medical applications. However, knowledge of the underlying molecular mechanisms remains limited. This study reports that MoS₂ nanosheets induces ferroptosis in vivo and in vitro, which is caused by the nanosheet themselves rather than by the dissolved ions. MoS₂ nanosheets induce ferroptosis in epithelial (BEAS-2B) and macrophage (RAW264.7) cells due to nuclear receptor coactivator 4 (NCOA4)-dependent excusive ferritinophagy and the inhibition of ferroportin-1 (FPN). In this process, most of the MoS₂ nanosheets enter the cells via macropinocytosis and are localized to the lysosome, contributing to an increase in the lysosomal membrane permeability. At the same time, NCOA4-dependent ferritinophagy is activated, and ferritin is degraded in the lysosome, which generates Fe²⁺ .Fe²⁺ leaks into the cytoplasm, leading to ferroptosis. Furthermore, the inhibition of FPN further aggravates the overload of Fe²⁺ in the cell. It has also been observed that ferroptosis is increased in lung tissue in mouse models exposed to MoS₂ nanosheets. This work highlights a novel mechanism by which MoS₂ nanosheets induce ferroptosis by promoting NCOA4-dependent ferritinophagy and inhibiting FPN, which could be of importance to elucidate the toxicity and identify the medical applications of 2D nanoparticles.

Exploiting endocytosis for transfection of mRNA for cytoplasmatic delivery using cationic gold nanoparticles

Introduction

Gene therapy holds promise to cure various diseases at the fundamental level. For that, efficient carriers are needed for successful gene delivery. Synthetic 'non-viral' vectors, as cationic polymers, are quickly gaining popularity as efficient vectors for transmitting genes. However, they suffer from high toxicity associated with the permeation and poration of the cell membrane. This toxic aspect can be eliminated by nanoconjugation. Still, results suggest that optimising the oligonucleotide complexation, ultimately determined by the size and charge of the nanovector, is not the only barrier to efficient gene delivery.

Methods

We herein develop a comprehensive nanovector catalogue comprising different sizes of Au NPs functionalized with two different cationic molecules and further loaded with mRNA for its delivery inside the cell.

Results and Discussion

Tested nanovectors showed safe and sustained transfection efficiencies over 7 days, where 50 nm Au NPs displayed the highest transfection rates. Remarkably, protein expression was increased when nanovector transfection was performed combined with chloroquine. Cytotoxicity and risk assessment demonstrated that nanovectors are safe, ascribed to lesser cellular damage due to their internalization and delivery via endocytosis. Obtained results may pave the way to design advanced and efficient gene therapies for safely transferring oligonucleotides.

Novel Developments to Enable Treatment of CNS Diseases with Targeted Drug Delivery

The blood-brain barrier (BBB) is a major hurdle for the development of systemically delivered drugs against diseases of the central nervous system (CNS). Because of this barrier there is still a huge unmet need for the treatment of these diseases, despite years of research efforts across the pharmaceutical industry. Novel therapeutic entities, such as gene therapy and degradomers, have become increasingly popular in recent years, but have not been the focus for CNS indications so far. To unfold their full potential for the treatment of CNS diseases, these therapeutic entities will most likely have to rely on innovative delivery technologies. Here we will describe and assess approaches, both invasive and non-invasive, that can enable, or at least increase, the probability of a successful drug development of such novel therapeutics for CNS indications.

Endocytosis-mediated redistribution of antibiotics targets intracellular bacteria

The increasing emergence and dissemination of antibiotic resistance pose a severe threat to overwhelming healthcare practices worldwide. The lack of new antibacterial drugs urgently calls for alternative therapeutic strategies to combat multidrug-resistant (MDR) bacterial pathogens, especially those that survive and replicate in host cells, causing relapse and recurrence of infections. Intracellular drug delivery is a direct efficient strategy to combat invasive pathogens by increasing the accumulation of antibiotics. However, the increased accumulation of antibiotics in the infected host cells does not mean high efficacy. The difficulty of treatment lies in the efficient intracellular delivery of antibiotics to the pathogen-containing compartments. Here, we first briefly review the survival mechanisms of intracellular bacteria to facilitate the exploration of potential antibacterial targets for precise delivery. Furthermore, we provide an overview of endocytosis-mediated drug delivery systems, including the biomedical and physicochemical properties modulating the endocytosis and intracellular redistribution of antibiotics. Lastly, we summarize the targets and payloads of recently described intracellular delivery systems and their modes of action against diverse pathogenic bacteria-associated infections. This overview of endocytosis-mediated redistribution of antibiotics sheds light on the development of novel delivery platforms and alternative strategies to combat intracellular bacterial pathogens.

On the size-dependent internalization of sub-hundred polymeric nanoparticles

The understanding of the interaction between nanoparticles (NPs) and cells is crucial to design nanocarriers with high therapeutic relevance. In this study, we exploited a microfluidics device to synthesize homogeneous suspensions of NPs with ≈ 30, 50, and 70 nm of size. Afterward, we investigated their level and mechanism of internalization when exposed to different types of cells (endothelial cells, macrophages, and fibroblasts). Our results show that all NPs were cytocompatible and internalized by the different cell types. However, NPs uptake was size-dependent, being the maximum uptake efficiency observed for the 30 nm NPs. Moreover, we demonstrate that size can lead to distinct interactions with different cells. For instance, 30 nm NPs were internalized with an increasing trend over time by endothelial cells, while a steady and a decreasing trend were observed when incubated with LPS-stimulated macrophages and fibroblasts, respectively. Finally, the use of different chemical inhibitors (chlorpromazine, cytochalasin-D, and nystatin), and low temperature (4 °C) indicated that phagocytosis/micropinocytosis are the main internalization mechanism for all NPs sizes. However, different endocytic pathways were initiated in the presence of particular NP sizes. In endothelial cells, for example, caveolin-mediated endocytosis occurs primarily in the presence of 50 nm NPs, whereas clathrin-mediated endocytosis substantially promotes the internalization of 70 nm NPs. This evidence demonstrates the importance of size in the NPs design for mediating interaction with specific cell types.

RGD-decorated PLGA nanoparticles improved effectiveness and safety of cisplatin for lung cancer therapy

Upon extensive pharmaceutical and biomedical research to treat lung cancer indicates that lung cancer remains one of the deadliest diseases and the leading cause of death in men and women worldwide. Lung cancer remains untreated and has a high mortality rate due to the limited potential for effective treatment with existing therapies. This highlights the urgent need to develop an effective, precise and sustainable solutions to treat lung cancer. In this study, we developed RGD receptor-targeted PLGA nanoparticles for the controlled and targeted co-delivery of cisplatin (CDDP) and upconversion nanoparticles (UCNP) in lung cancer therapy. Pluronic F127-RGD conjugate was synthesized by carbodiimide chemistry method and the conjugation was confirmed by FTIR and ¹HNMR spectroscopy techniques. PLGA nanoparticles were developed by the double emulsification method, then the surface of the prepared nanoparticles was decorated with Pluronic F127-RGD conjugate. The prepared formulations were characterized for their particle size, polydispersity index, zeta potential, surface morphology, drug encapsulation efficiency, and in vitro drug release and haemolysis studies. Pharmacokinetic studies and safety parameters in BAL fluid were assessed in rats. Histopathology of rat lung tissue was performed. The obtained results of particle sizes of the nanoparticle formulations were found 100-200 nm, indicating the homogeneity of dispersed colloidal nanoparticles formulations. Transmission Electron Microscopy (TEM) revealed the spherical shape of the prepared nanoparticles. The drug encapsulation efficiency of PLGA nanoparticles was found to range from 60% to 80% with different nanoparticles counterparts. RGD receptor-targeted PLGA nanoparticles showed controlled drug release for up to 72 h. Further, RGD receptor-targeted PLGA nanoparticles achieved higher cytotoxicity in compared to CFT, CFT, and Ciszest-50 (marketed CDDP injection). The pharmacokinetic study revealed that RGD receptor-targeted PLGA nanoparticles were 4.6-fold more effective than Ciszest-50. Furthermore, RGD receptor-targeted PLGA nanoparticles exhibited negligible damage to lung tissue, low systemic toxicity, and high biocompatible and safety in lung tissue. The results of RGD receptor-targeted PLGA nanoparticles indicated that it is a promising anticancer system that could further exploited as a potent therapeutic approach for lung cancer.

Drug Delivery Systems in Regenerative Medicine: An Updated Review

Modern drug discovery methods led to evolving new agents with significant therapeutic potential. However, their properties, such as solubility and administration-related challenges, may hinder their benefits. Moreover, advances in biotechnology resulted in the development of a new generation of molecules with a short half-life that necessitates frequent administration. In this context, controlled release systems are required to enhance treatment efficacy and improve patient compliance. Innovative drug delivery systems are promising tools that protect therapeutic proteins and peptides against proteolytic degradation where controlled delivery is achievable. The present review provides an overview of different approaches used for drug delivery.

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

Both gallic and citrate are well-established antioxidants that show promise as new selective anti-cancer drugs. Gold nanoparticles (AuNPs) as well can be developed as flexible and nontoxic nano-carriers for anti-cancer drugs. This article evaluating the efficiency and biocompatibility of gallic acid and citrate capping gold nanoparticles to be used as anti-cancer drug. The biosafety and therapeutic efficiency of prepared nano-formulations were tested on Hela and normal BHK cell line. Gold nanospheres coated with citrate and gallate were synthesized via wet chemical reduction method. The prepared nano-formulations, citrate and gallate coated gold nanospheres (Cit-AuNPs and Ga-AuNPs), were characterized with respect to their morphology, FTIR spectra, and physical properties. In addition, to assess their cytotoxicity, cell cycle arrest and flow cytometry to measure biological response were performed. Cit-Au NPs and Ga-Au NPs were shown to significantly reduce the viability of Hela cancer cells. Both G0/G cell cycle arrest and comet assay results showed that genotoxic effect was induced in Hela cells by Cit-Au NPs and Ga-Au NPs. The results of this study showed that Cit-Au NPs and Ga-AuNPs inhibit the growth of metastatic cervical cancer cells, which could have therapeutic implications.

Astatine-211-Labeled Gold Nanoparticles for Targeted Alpha-Particle Therapy via Intravenous Injection

Alpha-particle radiotherapy has gained considerable attention owing to its potent anti-cancer effect. ²¹¹At, with a relatively short half-life of 7.2 h, emits an alpha particle within a few cell diameters with high kinetic energy, which damages cancer cells with high biological effectiveness. In this study, we investigated the intravenous injection of ²¹¹At-labeled gold nanoparticles (AuNPs) for targeted alpha-particle therapy (TAT). Different kinds of surface-modified gold nanoparticles can be labeled with ²¹¹At in high radiochemical yield in 5 min, and no purification is necessary. The in vivo biodistribution results showed the accumulation of 5 nm ²¹¹At-AuNPs@mPEG at 2.25% injection dose per gram (% ID/g) in tumors within 3 h via the enhanced permeability and retention (EPR) effect. Additionally, we observed a long retention time in tumor tissues within 24 h. This is the first study to demonstrate the anti-tumor efficacy of 5 nm ²¹¹At-AuNPs@mPEG that can significantly suppress tumor growth in a pancreatic cancer model via intravenous administration. AuNPs are satisfactory carriers for ²¹¹At delivery, due to simple and efficient synthesis processes and high stability. The intravenous administration of 5 nm ²¹¹At-AuNPs@mPEG has a significant anti-tumor effect. This study provides a new framework for designing nanoparticles suitable for targeted alpha-particle therapy via intravenous injection.

PEGylated Gold Nanoparticles Target Age-Associated B Cells In Vivo

Engineered gold nanoparticles (GNPs) have become a useful tool in various therapeutic and diagnostic applications. Uncertainty remains regarding the possible impact of GNPs on the immune system. In this regard, we investigated the interactions of polymer-coated GNPs with B cells and their functions in mice. Surprisingly, we observed that polymer-coated GNPs mainly interact with the recently identified subpopulation of B lymphocytes named age-associated B cells (ABCs). Importantly, we also showed that GNPs did not affect cell viability or the percentages of other B cell populations in different organs. Furthermore, GNPs did not activate B cell innate-like immune responses in any of the tested conditions, nor did they impair adaptive B cell responses in immunized mice. Together, these data provide an important contribution to the otherwise limited knowledge about GNP interference with B cell immune function, and demonstrate that GNPs represent a safe tool to target ABCs in vivo for potential clinical applications.

A Nanomedicine Structure-Activity Framework for Research, Development, and Regulation of Future Cancer Therapies

Despite their clinical success in drug delivery applications, the potential of theranostic nanomedicines is hampered by mechanistic uncertainty and a lack of science-informed regulatory guidance. Both the therapeutic efficacy and the toxicity of nanoformulations are tightly controlled by the complex interplay of the nanoparticle's physicochemical properties and the individual patient/tumor biology; however, it can be difficult to correlate such information with observed outcomes. Additionally, as nanomedicine research attempts to gradually move away from large-scale animal testing, the need for computer-assisted solutions for evaluation will increase. Such models will depend on a clear understanding of structure-activity relationships. This review provides a comprehensive overview of the field of cancer nanomedicine and provides a knowledge framework and foundational interaction maps that can facilitate future research, assessments, and regulation. By forming three complementary maps profiling nanobio interactions and pathways at different levels of biological complexity, a clear picture of a nanoparticle's journey through the body and the therapeutic and adverse consequences of each potential interaction are presented.

Preparation of Triptolide Nano Drug Delivery System and Its Antitumor Activity In-Vitro

Triptolide (as an effective antitumor drug) is limited in clinical application because of its poor solubility and absorption in-vivo. Herein, we prepared folic acid modified polymer micelles to encapsulate triptolide and enhance its biologicalavailability coupled with antitumor effect. We prepared nano-micelles of triptolide through thin lipid film hydrational method. Physical properties and in vitro release characterization of Fol-Plla-cl-Peg-Plla-cl-Tmicelles were evaluated, while bioavailability of the formulation in rats was investigated. Tumor targeting potential of micelles was determined by observing the uptake of A549 cells. In-Vitro antitumor activity of micelles and free triptolide (API) was investigated with MTT assay. The prepared polymer material exhibited no cytotoxicity. The particle size distribution of Fol-Plla-cl-Peg-Plla-cl-T micelles was uniform and small, with good stability and high efficiency of entrapment. Triptolide In-Vitro release from micelles demonstrated slow and continuous released for 24 h. Compared with API, the half-life of micelles was prolonged, whilst its bioavailability in-vivo was increased by about 6.35 times. More importantly, Fol-Plla-cl-Peg-Plla-cl-T micelles significantly improved the antitumor activity of triptolide and showed good tumor targeting potential. Fol-Plla-cl-Peg-Plla-cl-T micelles could improve the bioavailability and antitumor activity of triptolide, amid demonstration of good tumor targeting and high safety.

Design principles of bioinspired interfaces for biomedical applications in therapeutics and imaging

In the past two decades, we have witnessed rapid developments in nanotechnology, especially in biomedical applications such as drug delivery, biosensing, and bioimaging. The most commonly used nanomaterials in biomedical applications are nanoparticles, which serve as carriers for various therapeutic and contrast reagents. Since nanomaterials are in direct contact with biological samples, biocompatibility is one of the most important issues for the fabrication and synthesis of nanomaterials for biomedical applications. To achieve specific recognition of biomolecules for targeted delivery and biomolecular sensing, it is common practice to engineer the surfaces of nanomaterials with recognition moieties. This mini-review summarizes different approaches for engineering the interfaces of nanomaterials to improve their biocompatibility and specific recognition properties. We also focus on design strategies that mimic biological systems such as cell membranes of red blood cells, leukocytes, platelets, cancer cells, and bacteria.

The effect of Gd-DOTA locations within PLGA-b-PEG micelle encapsulated IR-1061 on bimodal over-1000 nm near-infrared fluorescence and magnetic resonance imaging

Multimodal imaging is attractive in biomedical research because it can provide multidimensional information about objects that individual techniques cannot accomplish. In particular, combining over one-thousand-nanometer near-infrared (OTN-NIR) fluorescence and magnetic resonance (MR) imaging is promising for detecting lesions with high sensitivity and structural information. Herein, we describe the development of a bimodal OTN-NIR/MRI probe from gadolinium-tetraazacyclododecanetetraacetic acid (Gd-DOTA) conjugated poly(lactic-co-glycolic acid)-block-poly(ethylene glycol) copolymer (PLGA-b-PEG) micelle encapsulated IR-1061 at two different locations. One configuration contains Gd-DOTA at the end of the PEG of the hydrophilic shell and the other contains Gd-DOTA at the border of PLGA/PEG. The two structures show remarkable differences in fluorescence and R₁ relaxation rates in biological environments; the structure with Gd-DOTA at the border of PLGA/PEG exhibits stable fluorescence and T₁ signal distribution in live mice. The introduction ratio of Gd-DOTA to PEG is significant for controlling the properties of both structures; a higher Gd-DOTA ratio is preferable for the contrast enhancement effect. We found that Gd-DOTA ratios higher than 10% degraded the fluorescence intensity when Gd-DOTA was bound to the end of PEG. In contrast, the introduction of 70% Gd-DOTA at the border of PLGA/PEG did not exhibit a degraded signal, and the structural stability was enhanced with higher ratios of Gd-DOTA. In conclusion, we confirmed that the location of Gd-DOTA is a crucial factor in designing high-performance probes. The overall properties improve when Gd-DOTA is set on the border of PLGA/PEG. These improvements in the properties by controlling the probe structures are promising for future biomedical applications.

Long-Circulation and Brain Targeted Isoliquiritigenin Micelle Nanoparticles: Formation, Characterization, Tissue Distribution, Pharmacokinetics and Effects for Ischemic Stroke

Purpose

We designed a novel isoliquiritigenin (ISL) loaded micelle prepared with DSPE-PEG2000 as the drug carrier modified with the brain-targeting polypeptide angiopep-2 to improve the poor water solubility and low bioavailability of ISL for the treatment of acute ischemic stroke.

Methods

Thin film evaporation was used to synthesize the ISL micelles (ISL-M) modified with angiopep-2 as the brain targeted ligands. The morphology of the micelles was observed by the TEM. The particle size and zeta potential were measured via the nanometer particle size analyzer. The drug loading, encapsulation and in vitro release rates of micelles were detected by the HPLC. The UPLC-ESI-MS/MS methods were used to measure the ISL concentrations of ISL in plasma and main tissues after intravenous administration, and compared the pharmacokinetics and tissue distributions between ISL and ISL-M. In the MCAO mice model, the protective effects of ISL and ISL-M were confirmed via the behavioral and molecular biology experiments.

Results

The results showed that the drug loading of ISL-M was 7.63 ± 2.62%, the encapsulation efficiency was 68.17 ± 6.23%, the particle size was 40.87 ± 4.82 nm, and the zeta potential was -34.23 ± 3.35 mV. The in vitro release experiments showed that ISL-M had good sustained-release effect and pH sensitivity. Compared with ISL monomers, the ISL-M could significantly prolong the in vivo circulation time of ISL and enhance the accumulation in the brain tissues. The ISL-M could ameliorate the brain injury induced by the MCAO mice via inhibition of cellular autophagy and neuronal apoptosis. There were no the cellular structural damages and other adverse effects for ISL-M on the main tissues and organs.

Conclusion

The ISL-M could serve as a promising and ideal drug candidate for the clinical application of ISL in the treatment of acute ischemic stroke.

Ultrasmall-in-Nano: Why Size Matters

Gold nanoparticles (AuNPs) are continuing to gain popularity in the field of nanotechnology. New methods are continuously being developed to tune the particles' physicochemical properties, resulting in control over their biological fate and applicability to in vivo diagnostics and therapy. This review focuses on the effects of varying particle size on optical properties, opsonization, cellular internalization, renal clearance, biodistribution, tumor accumulation, and toxicity. We review the common methods of synthesizing ultrasmall AuNPs, as well as the emerging constructs termed ultrasmall-in-nano-an approach which promises to provide the desirable properties from both ends of the AuNP size range. We review the various applications and outcomes of ultrasmall-in-nano constructs in vitro and in vivo.

Macrophage-Targeted Nanomedicines for ARDS/ALI: Promise and Potential

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are characterized by progressive lung impairment typically triggered by inflammatory processes. The mortality toll for ARDS/ALI yet remains high because of the poor prognosis, lack of disease-specific inflammation management therapies, and prolonged hospitalizations. The urgency for the development of new effective therapeutic strategies has become acutely evident for patients with coronavirus disease 2019 (COVID-19) who are highly susceptible to ARDS/ALI. We propose that the lack of target specificity in ARDS/ALI of current treatments is one of the reasons for poor patient outcomes. Unlike traditional therapeutics, nanomedicine offers precise drug targeting to inflamed tissues, the capacity to surmount pulmonary barriers, enhanced interactions with lung epithelium, and the potential to reduce off-target and systemic adverse effects. In this article, we focus on the key cellular drivers of inflammation in ARDS/ALI: macrophages. We propose that as macrophages are involved in the etiology of ARDS/ALI and regulate inflammatory cascades, they are a promising target for new therapeutic development. In this review, we offer a survey of multiple nanomedicines that are currently being investigated with promising macrophage targeting potential and strategies for pulmonary delivery. Specifically, we will focus on nanomedicines that have shown engagement with proinflammatory macrophage targets and have the potential to reduce inflammation and reverse tissue damage in ARDS/ALI.

Lung cancer targeting efficiency of Silibinin loaded Poly Caprolactone /Pluronic F68 Inhalable nanoparticles: In vitro and In vivo study

Silibinin (SB) is shown to have an anticancer properties. However, its clinical therapeutic effects have been restricted due to its low water solubility and poor absorption after oral administration. The aim of this study was to develop SB-loaded PCL/Pluronic F68 nanoparticles for pulmonary delivery in the treatment of lung cancer. A modified solvent displacement process was used to make nanoparticles, which were then lyophilized to make inhalation powder, Nanoparticles were characterized with DSC, FTIR,SEM and In vitro release study. Further, a validated HPLC method was developed to investigate the Biodistribution study, pharmacokinetic parameters. Poly Caprolactone PCL / Pluronic F68 NPs showed the sustained release effect up to 48 h with an emitted (Mass median Aerodynamic diameter)MMAD and (Geometric size distribution)GSD were found to be 4.235 ±0.124 and 1.958±1.23 respectively. More specifically, the SB Loaded PCL/Pluronic F 68 NPs demonstrated long circulation and successful lung tumor-targeting potential due to their cancer-targeting capabilities. SB Loaded PCL/Pluronic F68 NPs significantly inhibited tumour growth in lung cancer-induced rats after inhalable administration. In a pharmacokinetics study, PCL/ Pluronic F68 NPs substantially improved SB bioavailability, with a more than 4-fold rise in AUC when compared to IV administration. These findings indicate that SB-loaded PCL/PluronicF68 nanoparticles may be a successful lung cancer therapy delivery system.

The influence of Gd-DOTA ratios conjugating PLGA-PEG micelles encapsulated IR-1061 in bimodal over–1000 nm near–infrared fluorescence and magnetic resonance imaging

Multimodal imaging can provide multidimensional information for understanding concealed microstructures or bioprocesses in biological objects. The combination of over–1000 nm near–infrared (OTN–NIR) fluorescence imaging and magnetic resonance (MR) imaging is...

Mixed-charge modification as a robust method to realize the antiviral ability of gold nanoparticles in a high protein environment

Pandemics caused by viruses have resulted in incalculable losses to human beings, which are exacerbated due to the lack of antiviral drugs. Sulfonic group modified nanomedicine has been proved to possess a broad-spectrum antiviral ability. However, it is very challenging to maintain the antiviral activity in a high protein environment in vivo. To improve the tolerance to the complex biological environment, sulfonic mixed-charge modified gold nanoparticles (MC_AuNPs) were prepared in this research by introducing positively charged ligands into sulfonic ligand modified gold nanoparticles. The MC_AuNPs showed excellent non-fouling ability while retaining comparable antiviral ability to single sulfonic ligand modified gold nanoparticles (MDS_AuNPs). The MC_AuNPs maintained their antiviral ability in 10 mg mL^-1 protein solutions, but the MDS_AuNPs completely lost their antiviral capability in 1 mg mL^-1 protein medium. The mixed-charge modification strategy provides a practical avenue to maintain the antiviral capability of HSPG mimicking nanoparticles in high protein environments.

Microfluidicmixing system for precise PLGA-PEG nanoparticles size control

In this study, a microfluidic device was employed to produce polymeric nanoparticles (NPs) with well-controlled sizes. The influence of several parameters in the synthesis process, namely, polymer concentration, flow rate and flow rate ratio between the aqueous and organic solutions was investigated. To evaluate the NPs size effect, three diameters were selected (30, 50 and 70nm). Their cytocompatibility was demonstrated on endothelial cells and macrophages. Additionally, their efficacy to act as drug carriers was assessed in an in vitro inflammatory scenario. NPs loaded and released diclofenac (DCF) in a size-dependent profile (smaller sizes presented lower DCF content and higher release rate). Moreover, 30nm NPs were the most effective in reducing prostaglandin E₂ concentration. Therefore, this study demonstrates that microfluidics can generate stable NPs with controlled sizes, high monodispersity and enhanced batch-to-batch reproducibility. Indeed, NPs size is a crucial parameter for drug encapsulation, release and overall biological efficacy.

Bioinspired drug delivery strategies for repurposing conventional antibiotics against intracellular infections

Bacteria have developed a wealth of strategies to avoid and resist the action of antibiotics, one of which involves pathogens invading and forming reservoirs within host cells. Due to the poor cell membrane permeability, stability and retention of conventional antibiotics, this renders current treatments largely ineffective, since achieving a therapeutically relevant antibiotic concentration at the site of intracellular infection is not possible. To overcome such challenges, current antibiotics are 'repurposed' via reformulation using micro- or nano-carrier systems that effectively encapsulate and deliver therapeutics across cellular membranes of infected cells. Bioinspired materials that imitate the uptake of biological particulates and release antibiotics in response to natural stimuli are recently explored to improve the targeting and specificity of this 'nanoantibiotic' approach. In this review, the mechanisms of internalization and survival of intracellular bacteria are elucidated, effectively accentuating the current treatment challenges for intracellular infections and the implications for repurposing conventional antibiotics. Key case studies of nanoantibiotics that have drawn inspiration from natural biological particles and cellular uptake pathways to effectively eradicate intracellular pathogens are detailed, clearly highlighting the rational for harnessing bioinspired drug delivery strategies.

Surface charge-dependent mitochondrial response to similar intracellular nanoparticle contents at sublethal dosages

Background

Considering the inevitability for humans to be frequently exposed to nanoparticles (NPs), understanding the biosafety of NPs is important for rational usage. As an important part of the innate immune system, macrophages are widely distributed in vital tissues and are also a dominant cell type that engulfs particles. Mitochondria are one of the most sensitive organelles when macrophages are exposed to NPs. However, previous studies have mainly reported the mitochondrial response upon high-dose NP treatment. Herein, with gold nanoparticles (AuNPs) as a model, we investigated the mitochondrial alterations induced by NPs at a sublethal concentration.

Results

At a similar internal exposure dose, different AuNPs showed distinct degrees of effects on mitochondrial alterations, including reduced tubular mitochondria, damaged mitochondria, increased reactive oxygen species, and decreased adenosine triphosphate. Cluster analysis, two-way ANOVA, and multiple linear regression suggested that the surface properties of AuNPs were the dominant determinants of the mitochondrial response. Based on the correlation analysis, the mitochondrial response was increased with the change in zeta potential from negative to positive. The alterations in mitochondrial respiratory chain proteins indicated that complex V was an indicator of the mitochondrial response to low-dose NPs.

Conclusion

Our current study suggests potential hazards of modified AuNPs on mitochondria even under sublethal dose, indicates the possibility of surface modification in biocompatibility improvement, and provides a new way to better evaluation of nanomaterials biosafety.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12989-021-00429-8.

Engineering of stealth (maghemite/PLGA)/chitosan (core/shell)/shell nanocomposites with potential applications for combined MRI and hyperthermia against cancer

(Maghemite/poly(d,l-lactide-co-glycolide))/chitosan (core/shell)/shell nanoparticles have been prepared reproducibly by nanoprecipitation solvent evaporation plus coacervation (production performance ≈ 45%, average size ≈ 325 nm). Transmission electron microscopy, energy dispersive X-ray spectroscopy, electrophoretic determinations, and X-ray diffraction patterns demonstrated the satisfactory embedment of iron oxide nanocores within the solid polymer matrix and the formation of an external shell of chitosan in the nanostructure. The adequate magnetic responsiveness of the nanocomposites was characterized in vitro by hysteresis cycle determinations and by visualization of the nanosystem under the influence of a 0.4 T permanent magnet. Safety and biocompatibility of the (core/shell)/shell particles were based on in vitro haemocompatibility studies and cytotoxicity tests against HFF-1 human foreskin fibroblasts and on ex vivo toxicity assessments on tissue samples from Balb/c mice. Transversal relaxivities, determined in vitro at a low magnetic field of 1.44 T, demonstrated their capability as T2 contrast agents for magnetic resonance imaging, being comparable to that of some iron oxide-based contrast agents. Heating properties were evaluated in a high frequency alternating electromagnetic gradient: a constant maximum temperature of ≈46 °C was generated within ≈50 min, while antitumour hyperthermia tests on T-84 colonic adenocarcinoma cells proved the relevant decrease in cell viability (to ≈ 39%) when treated with the nanosystem under the influence of that electromagnetic field. Finally, in vivo magnetic resonance imaging studies and ex vivo histology determinations of iron deposits postulated the efficacy of chitosan to provide long-circulating capabilities to the nanocomposites, retarding nanoparticle recognition by the mononuclear phagocyte system. To our knowledge, this is the first study describing such a type of biocompatible and long-circulating nanoplatform with promising theranostic applications (biomedical imaging and hyperthermia) against cancer.

Impact of macroporous silica nanoparticles at sub-50nm on bio-behaviors and biosafety in drug-resistant cancer models

The in vivo bio-behaviors and biosafety of nanoparticles were demonstrated to be closely correlated with particle sizes, which illustrated whether they could be used as the effective drug delivery carriers. Though tumor penetration capabilities of the small pore sized-mesoporous silica nanoparticles (MSNs) were reported to be in a particle size-dependent manner, the size effects of large pore sized-MSNs on the safe and effective cancer resistance treatment, especially at sub-50 nm, were not explicitly evaluated. In this study, we fabricate the 20 nm and 50 nm MSNs, and aim at investigating their difference in tumor accumulation, penetration, retention and toxicity both in vitro and in vivo. Our results showed that these two particle sized-MSNs possessed the excellent tumor penetration capabilities both in resistant human hepatocellular carcinoma cells-cultured spheroids and in the corresponding xenograft mice models, but the 50 nm MSNs seemed to have the better tumor accumulation and retention effects than the 20 nm MSNs. Moreover, the 50 nm MSNs displayed the lower toxicities than the 20 nm MSNs whatever on resistant cancer cell lines or on zebrafish embryos, indicating the greater systematic biosafety. In a word, our data provide the evidence that selection of the large pore-sized MSNs at the appropriate particle size (not the smaller the better) as bio-macromolecule nanocarriers will play a key role in the safe and effective treatment against cancer resistance.

The Effect of Chemical Structure of OEG Ligand Shells with Quaternary Ammonium Moiety on the Colloidal Stabilization, Cellular Uptake and Photothermal Stability of Gold Nanorods

PURPOSE

Plasmonic photothermal cancer therapy by gold nanorods (GNRs) emerges as a promising tool for cancer treatment. The goal of this study was to design cationic oligoethylene glycol (OEG) compounds varying in hydrophobicity and molecular electrostatic potential as ligand shells of GNRs. Three series of ligands with different length of OEG chain (ethylene glycol units = 3, 4, 5) and variants of quaternary ammonium salts (QAS) as terminal functional group were synthesized and compared to a prototypical quaternary ammonium ligand with alkyl chain - (16-mercaptohexadecyl)trimethylammonium bromide (MTAB).

METHODS

Step-by-step research approach starting with the preparation of compounds characterized by NMR and HRMS spectra, GNRs ligand exchange evaluation through characterization of cytotoxicity and GNRs cellular uptake was used. A method quantifying the reshaping of GNRs was applied to determine the effect of ligand structure on the heat transport from GNRs under fs-laser irradiation.

RESULTS

Fourteen out of 18 synthesized OEG compounds successfully stabilized GNRs in the water. The colloidal stability of prepared GNRs in the cell culture medium decreased with the number of OEG units. In contrast, the cellular uptake of OEG+GNRs by HeLa cells increased with the length of OEG chain while the structure of the QAS group showed a minor role. Compared to MTAB, more hydrophilic OEG compounds exhibited nearly two order of magnitude lower cytotoxicity in free state and provided efficient cellular uptake of GNRs close to the level of MTAB. Regarding photothermal properties, OEG compounds evoked the photothermal reshaping of GNRs at lower peak fluence (14.8 mJ/cm2) of femtosecond laser irradiation than the alkanethiol MTAB.

CONCLUSION

OEG+GNRs appear to be optimal for clinical applications with systemic administration of NPs not-requiring irradiation at high laser intensity such as drug delivery and photothermal therapy inducing apoptosis.

Physicochemical Variation in Nanogold-Based Ayurved Medicine Suvarna Bhasma Produced by Various Manufacturers Lead to Different In Vivo Bioaccumulation Profiles

Suvarna Bhasma (SB) is a gold particle-based medicine that is used in Ayurved to treat tuberculosis, arthritis and nervous diseases. Traditionally, the Ayurved preparation processes of SB do exist, but they are all long, tedious and involve several steps. Due to this, there is a possibility of bypassing the necessary Ayurved processes or non-adherence to all steps or use of synthetic gold particles. Our aim is to characterize 5 commercial SB preparations from 5 different manufacturers. A comparative physicochemical, pharmacokinetic (PK) and bioaccumulation study was carried out on all the 5 SB preparations. The general appearance such as color and texture of these 5 samples were different from each other. The size, shape and gold concentration (from 32-98 wt%) varied among all the 5 SBs. The accumulation of ionic gold in zebrafish and gold concentration profiles in rat blood were found to be significantly different for all the 5 SBs. Non-compartmental PK model obtained from the concentration-time profile showed significant differences in various PK parameters such as peak concentration (C_max), half-life (t_1/2) and terminal elimination slope (λ_z) for all the 5 SB preparations. SB-B showed the highest C_max (8.55 μg/L), whereas SB-D showed the lowest C_max (4.66 μg/L). The dissolution of ionic gold from SBs in zebrafish tissue after the oral dose had a 5.5-fold difference between the highest and lowest ionic gold concentrations. All the 5 samples showed distinct physicochemical and biological properties. Based on characteristic microscopic morphology, it was found that 2 preparations among them were suspected of being manufactured by non-adherence to the mentioned Ayurved references.

Dual effects of fibrinogen decoration on the tuning of silica nanoparticles-induced autophagic response: The implication of sedimentation and internalization

Due to the blooming development of nanotechnology, the further understanding of nanomaterials-induced toxicity has been demanded. Following their introduction into a biological matrix, the surface of nanoparticles (NPs) is covered by protein layer, namely corona, which imparts a new biological identity to NPs. Here, we showed that fibrinogen (Fg), but not albumin (BSA) or hemoglobin (Hb), decoration on the surface of silica nanoparticles (SiO₂ NPs) ameliorate their pro-autophagic activity in non-phagocytic cells. Surprisingly, this effect of Fg was compromised in phagocytic cells. Further mechanistic investigation suggested coronal Fg has dual effects on the tuning of SiO₂ NPs-induced autophagic response. First, Fg decoration blocks SiO₂ NPs sedimentation through stabilize SiO₂ NPs suspension; secondly, Fg coverage inhibits SiO₂ NPs' cellular internalization. These findings provided important insights into the understanding of NPs-corona complexes behaviors and indicate future directions for the investigation of corona-mediated biological activities.

Mixed micelles for enhanced oral bioavailability and hypolipidemic effect of liquiritin: preparation, in vitro and in vivo evaluation

OBJECTIVES

Liquiritin, as one of the main flavonoids in Glycyrrhiza, exhibits extensive pharmacological effects, such as the anti-oxidant, anti-inflammatory, anti-tumor and so on. Herein, the aqueous solubility and oral bioavailability of liquiritin was purposely enhanced via the preparation of the mixed micelles.

METHODS

The liquiritin-loaded micelles (LLM) were fabricated via thin-film dispersion method. The optimal LLM formulation was evaluated through physical properties including particle size (PS), encapsulation efficiency (EE) and drug loading (DL). In vitro accumulate release as well as in vivo pharmacokinetics were also evaluated. Moreover, the hypolipidemic activity of LLM was observed in the hyperlipidemia mice model.

RESULTS

The LLM exhibited a homogenous spherical shape with small mean PS, good stability and high encapsulation efficiency. The accumulate release rates in vitro of the LLM were obviously higher than free liquiritin. The oral bioavailability of the formulation was heightened by 3.98 times in comparison with the free liquiritin. More importantly, LLM increased the hypolipidemic and effect of alleviating lipid metabolism disorder in hepatocytes of liquiritin in hyperlipidemia mice model.

CONCLUSIONS

Collectively, the improved solubility of liquiritin in water coupled with its enhanced oral bioavailability and concomitant hypolipidemic activity could be attributed to the incorporation of the drug into the mixed micelles.

Cellular uptake and toxicity of gold nanoparticles on two distinct hepatic cell models

Gold nanoparticles (AuNPs) have huge potential for various biomedical applications, but their successful use depends on their uptake and possible toxicity in the liver, their main site for accumulation. Therefore, in this work we compared the cytotoxic effects induced by AuNPs with different size (~ 15 nm and 60 nm), shape (nanospheres and nanostars) and capping [citrate- or 11-mercaptoundecanoic acid (MUA)], in human HepaRG cells or primary rat hepatocytes (PRH) cultivated with serum-free or Foetal Bovine Serum (FBS)-supplemented media. The safety assessment of the AuNPs demonstrated that overall they present low toxicity towards hepatic cells. Among all the tested AuNPs, the smaller 15 nm spheres displayed the highest toxicity. The toxicological effect was capping, size and cell-type dependent with citrate-capping more toxic than MUA (PRH with FBS), the 15 nm AuNPs more toxic than 60 nm counterparts and PRH more sensitive, as compared to the HepaRG cells. The incubation with FBS-free media produced aggregation of AuNPs while its presence greatly influenced the toxicity outcomes. The cellular uptake of AuNPs was shape, size and capping dependent in PRH cultivated in FBS-supplemented media, and significantly different between the two types of cells with extensively higher internalization of AuNPs in PRH, as compared to the HepaRG cells. These data show that the physical-chemical properties of AuNPs, including size and shape, as well as the type of cellular model, greatly influence the interaction of the AuNPs with the biological environment and consequently, their toxicological effects.

Improved Oral Bioavailability and Hypolipidemic Effect of Syringic Acid via a Self-microemulsifying Drug Delivery System

This study aimed to develop a self-microemulsifying drug delivery system (SMEDDS) to enhance the solubility, oral bioavailability, and hypolipidemic effects of syringic acid (SA), a bioactive and poorly-soluble polyphenol. Based on the response surface methodology-central composite design (RSM-CCD), an optimum formulation of SA-SMEDDS, consisting of ethyl oleate (oil, 12.30%), Cremophor-EL (surfactant, 66.25%), 1,2-propanediol (cosurfactant, 21.44%), and drug loading (50 mg/g), was obtained. The droplets of SA-SMEDDS were nanosized (16.38 ± 0.12 nm), spherically shaped, and homogeneously distributed (PDI = 0.058 ± 0.013) nanoparticles with high encapsulation efficiency (98.04 ± 1.39%) and stability. In vitro release study demonstrated a prolonged and controlled release of SA from SMEDDS. In vitro cell studies signified that SA-SMEDDS droplets substantially promoted cellular internalization. In comparison with the SA suspension, SA-SMEDDS showed significant prolonged T_max, t_1/2, and MRT after oral administration. Also, SA-SMEDDS exhibited a delayed in vivo elimination, increased bioavailability (2.1-fold), and enhanced liver accumulation. Furthermore, SA-SMEDDS demonstrated significant improvement in alleviating serum lipid profiles and hepatic steatosis in high-fat diet-induced hyperlipidemia in mice. Collectively, SMEDDS demonstrated potential as a nanosystem for the oral delivery of SA with enhanced bioavailability and hypolipidemic effects.

Nanomedicines for Subcellular Targeting: The Mitochondrial Perspective

BACKGROUND

Over the past decade, there has been a surge in the number of mitochondrialactive therapeutics for conditions ranging from cancer to aging. Subcellular targeting interventions can modulate adverse intracellular processes unique to the compartments within the cell. However, there is a dearth of reviews focusing on mitochondrial nano-delivery, and this review seeks to fill this gap with regards to nanotherapeutics of the mitochondria.

METHODS

Besides its potential for a higher therapeutic index than targeting at the tissue and cell levels, subcellular targeting takes into account the limitations of systemic drug administration and significantly improves pharmacokinetics. Hence, an extensive literature review was undertaken and salient information was compiled in this review.

RESULTS

From literature, it was evident that nanoparticles with their tunable physicochemical properties have shown potential for efficient therapeutic delivery, with several nanomedicines already approved by the FDA and others in clinical trials. However, strategies for the development of nanomedicines for subcellular targeting are still emerging, with an increased understanding of dysfunctional molecular processes advancing the development of treatment modules. For optimal delivery, the design of an ideal carrier for subcellular delivery must consider the features of the diseased microenvironment. The functional and structural features of the mitochondria in the diseased state are highlighted and potential nano-delivery interventions for treatment and diagnosis are discussed.

CONCLUSION

This review provides an insight into recent advances in subcellular targeting, with a focus on en route barriers to subcellular targeting. The impact of mitochondrial dysfunction in the aetiology of certain diseases is highlighted, and potential therapeutic sites are identified.

Exploring Diffusion and Cellular Uptake: Charged Gold Nanoparticles in an in Vitro Breast Cancer Model

Gold nanoparticles have emerged as a prominent tool in nanomedicine, particularly for applications in cancer diagnostic and treatment. One of the challenges for the successful implementation of gold nanoparticles in cancer therapy is their delivery to the specific cancer area within the tumor microenvironment. The presence of cancer enables a poorly organized vascularization system, increasing the pressure with the microenvironment, limiting the uptake of particles. The physicochemical properties of the gold nanoparticles (size, shape, and surface charge) also have a significant effect on diffusion to the tumor site and cellular uptake. In this work, we analyzed the transport of 10 nm gold nanoparticles with different surface charges (neutral, negative, and positive) through a hydrogel composite. Three-dimensional in vitro models composed of breast cancer cells loaded in the hydrogel composite were used for the qualitative and quantitative evaluation of cellular uptake of the gold nanoparticles. Surprisingly, an inverse correlation between the diffusion coefficients of the nanoparticles and cellular uptake was demonstrated. Positively charged gold nanoparticles displayed high cellular uptake, although their diffusion coefficient indicated slow transport through the hydrogel matrix. Neutral particles, on the other hand, displayed fast diffusion but the lowest cellular uptake. The results obtained indicate that nanoparticle diffusion and cellular uptake should be studied together in realistic in vitro models for a true evaluation of transport in tumor microenvironments.

Folate-induced nanostructural changes of oligochitosan nanoparticles and their fate of cellular internalization by melanoma

This study examined the effects of folate environment of oligochitosan nanoparticles on their cellular internalization profiles in human melanoma cells. The conjugates and nanoparticles of oligochitosan-folate, oligochitosan-carboxymethyl-5-fluorouracil, and oligochitosan-folate-carboxymethyl-5-fluorouracil were synthesized by carbodiimide chemistry and prepared by nanospray drying technique respectively. The cellular internalization profiles of oligochitosan-folate nanoparticles against the human malignant melanoma cell line (SKMEL-28) were evaluated using confocal scanning electron microscopy technique through fluorescence labelling and endocytic inhibition, as a function of nanoparticulate folate content, size, polydispersity index, zeta potential, shape, surface roughness and folate population density. The cytotoxicity and cell cycle arrest characteristics of oligochitosan-folate-carboxymethyl-5-fluorouracil nanoparticles, prepared with an optimal folate content that promoted cellular internalization, were evaluated against the oligochitosan-folate and oligochitosan-carboxymethyl-5-fluorouracil conjugate nanoparticles. The oligochitosan-folate conjugate nanoparticles were endocytosed by melanoma cells via caveolae- and lipid raft-mediated endocytic pathways following them binding to the cell surface folate receptor. Nanoparticles that were larger and with higher folic acid contents and zeta potentials exhibited a higher degree of cellular internalization. Excessive conjugation of nanoparticles with folate resulted in a high nanoparticulate density of folate which hindered nanoparticles-cell interaction via folate receptor binding and reduced cellular internalization of nanoparticles. Conjugating oligochitosan with 20 %w/w folate was favorable for cellular uptake as supported by in silico models. Conjugating of oligochitosan nanoparticles with carboxymethyl-5-fluorouracil and 20 %w/w of folate promoted nanoparticles-folate receptor binding, cellular internalization and cancer cell death via cell cycle arrest at S phase at a lower drug dose than oligochitosan-carboxymethyl-5-fluorouracil conjugate nanoparticles and neat carboxymethyl-5-fluorouracil.