Elimination Pathways of Nanoparticles

Glucocorticoid pre-administration improves LNP-mRNA mediated protein replacement and genome editing therapies

Lipid nanoparticles (LNPs) are among the most promising non-viral mRNA delivery systems for gene therapeutic applications. However, the in vivo delivery of LNP-mRNA remains challenging due to multiple intrinsic barriers that hinder LNPs from reaching their target cells. In this study, we sought to enhance LNP delivery by manipulating intrinsic regulatory mechanisms involved in their metabolism. We demonstrated that activation of the glucocorticoid pathway significantly increased the systemic delivery of LNP-mRNA in both mice and monkeys, achieving up to a fourfold improvement. This enhancement was primarily attributed to the glucocorticoid-mediated inhibition of macrophage phagocytosis in circulation and the liver, which resulted in higher LNP accumulation in hepatocytes. Consequently, glucocorticoid activation improved the therapeutic efficacy of LNP-based protein replacement and CRISPR/Cas9 genome editing therapies. Together, these findings establish a practical strategy to enhance the systemic delivery of RNA-based protein replacement and genome editing therapeutics, highlighting the potential of manipulating endogenous mechanisms to optimize exogenous gene delivery.

Lipid Nanoparticles and PEG: Time Frame of Immune Checkpoint Blockade Can Be Controlled by Adjusting the Rate of Cellular Uptake of Nanoparticles

The engineerability of lipid nanoparticles (LNPs) and their ability to deliver nucleic acids make LNPs attractive tools for cancer immunotherapy. LNP-based gene delivery can be employed for various approaches in cancer immunotherapy, including encoding tumor-associated antigens and silencing of negative immune checkpoint proteins. For example, LNPs carrying small interfering RNAs can offer several advantages, including sustained and durable inhibition of an immune checkpoint protein. Due to their tunable design, modifying the lipid composition of LNPs can regulate the rate of their uptake by immune cells and the rate of gene silencing. Controlling the kinetics of LNP uptake provides additional flexibility and strategies to generate appropriate immunomodulation in the tumor microenvironment. Here, we evaluated the effects of polyethylene glycol (PEG) content ranging from 0.5 to 6 mol % on the cellular uptake of LNPs by immune cells and gene silencing of PD-L1 after intratumoral administration. We evaluated the cellular uptake and PD-L1 blockade in vitro in cell studies and in vivo using the YUMM1.7 melanoma tumor model. Cell studies showed that the rate of cell uptake was inversely correlated to an increasing mol % of PEG in a linear relationship. In the in vivo studies, 0.5% PEG LNP initiated an immediate effect in the tumor with a significant decrease in the PD-L1 expression of immune cells observed within 24 h. In comparison, the gene silencing effect of 6% PEG LNP was delayed, with a significant decrease of PD-L1 expression in immune cell subsets being observed 72 h after administration. Notably, performance of the 6% PEG LNP at 72 h was comparable to that of the 0.5% PEG LNP at 24 h. Overall, this study suggests that PEG modifications and intratumoral administration of LNPs can be a promising strategy for an effective antitumor immune response.

Ultrasound-mediated nanomaterials for the treatment of inflammatory diseases

Sterile and infection-associated inflammatory diseases are becoming increasingly prevalent worldwide. Conventional drug therapies often entail significant drawbacks, such as the risk of drug overdose, the development of drug resistance in pathogens, and systemic adverse reactions, all of which can undermine the effectiveness of treatments for these conditions. Nanomaterials (NMs) have emerged as a promising tool in the treatment of inflammatory diseases due to their precise targeting capabilities, tunable characteristics, and responsiveness to external stimuli. Ultrasound (US), a non-invasive and effective treatment method, has been explored in combination with NMs to achieve enhanced therapeutic outcomes. This review provides a comprehensive overview of the recent advances in the use of US-mediated NMs for treating inflammatory diseases. A comprehensive introduction to the application and classification of US was first presented, emphasizing the advantages of US-mediated NMs and the mechanisms through which US and NMs interact to enhance anti-inflammatory therapy. Subsequently, specific applications of US-mediated NMs in sterile and infection-associated inflammation were summarized. Finally, the challenges and prospects of US-mediated NMs in clinical translation were discussed, along with an outline of future research directions. This review aims to provide insights to guide the development and improvement of US-mediated NMs for more effective therapeutic interventions in inflammatory diseases.

Exacerbated hepatotoxicity in in vivo and in vitro non-alcoholic fatty liver models by biomineralized copper sulfide nanoparticles

Copper sulfide nanoparticles (NPs) synthesized through biomineralization have significant commercial potential as photothermal agents, while the safety evaluation of these NPs, especially for patients with non-alcoholic fatty liver (NAFL), remains insufficient. To explore the differential hepatotoxicity of copper sulfide NPs in NAFL conditions, we synthesized large-sized (LNPs, 15.1 nm) and small-sized (SNPs, 3.5 nm) BSA@Cu2-xS NPs. A NAFL rat model fed with high fat diet (HFD) was successfully established for a 14-day subacute toxicity study by daily repeated administration of BSA@Cu2-xS NPs. Our findings from serum biochemistry and histopathological examinations revealed that copper sulfide at both sizes NPs induced more pronounced liver damage in NAFL rats than rats fed with normal diet. Transcriptome sequencing analysis showed that LNPs activated inflammation and DNA damage repair pathways in the livers of NAFL rats, while SNPs displayed minimal inflammation. A three-dimensional spheroid model of NAFL developed in our in-house cell spheroid culture honeycomb chips demonstrated that LNPs, but not SNPs, triggered a distinct release of inflammatory factors and increased reactive oxygen species through Kupffer cells. These results highlight that NAFL condition exacerbated the hepatotoxicity of BSA@Cu2-xS NPs, with SNPs emerging as safer photothermal agents compared to LNPs, suggesting superior potential for clinical applications.

Advances in cuproptosis harnessing copper-based nanomaterials for cancer therapy

Cuproptosis, a newly identified programmed cell death form, is characterized by excessive copper accumulation in cells, resulting in mitochondria damage and toxic protein stress, ultimately causing cell death. Given the considerable therapeutic promise of copper toxicity in cancer treatment, copper-based nanomaterials that induce copper death have attracted interest as a promising approach for tumor therapy. This review comprehensively introduces the mechanisms of cuproptosis and the associated regulatory genes, including both positive and negative regulatory regulators, and systematically summarizes the application of various nanoparticles in inducing cuproptosis, ranging from inorganic copper compounds to delivery systems. These nanoparticles offer significant advantages, such as improving copper absorption, extending the duration of effectiveness, enhancing the precision of copper release, increasing biocompatibility, and serving as enhancers in combination therapy. In conclusion, the authors present a detailed overview and insights into the current research directions of nanoplatforms that facilitate copper-induced cancer treatment, establishing a foundation for the future development of effective nanomedicines that induce cuproptosis and offering new possibilities and treatment strategies for tumor therapy.

Macrophage Membrane-Encapsulated Carbon Dots for Precise Targeting Diagnosis and Treatment of Bacterial Infections

How to accurately diagnose and treat bacterial infections in vivo remains a huge challenge. Therefore, we have developed a targeted delivery nanosystem by coextruding the pretreated macrophage membrane of S. aureus with carbon dots (M@CD). The M@CD nanosystem demonstrates potent antibacterial effects both in vivo and in vitro through the generation of reactive oxygen species (ROS). Furthermore, M@CD exhibits enhanced targeting ability and stable fluorescence properties, addressing issues such as poor targeting efficiency and high immunogenicity in vivo. This innovative approach enables infection site specific aggregation and elimination of bacterial infections, thereby providing a promising strategy for the integrated diagnosis, treatment, and monitoring of bacterial infections.

Assessing the Efficacy of Pyrolysis-Gas Chromatography-Mass Spectrometry for Nanoplastic and Microplastic Analysis in Human Blood

Humans are constantly exposed to micro- and nanosized plastics (MNPs); however, there is still limited understanding of their fate within the body, partially due to limitations with current analytical techniques. The current study assessed the appropriateness of pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) analysis for the quantification of a range of polymers in human blood. An extraction protocol that reduced matrix interferences (false positives) of polyethylene (PE) and polyvinyl chloride (PVC) was developed and validated. Extraction recoveries ranged 7-109%, although surface-modified polystyrene (carboxylated) increased nanoparticle recoveries from 17 to 52%. Realistic detection limits were calculated for each polymer, accounting for matrix suppression and extraction recovery. These were up to 20 times higher than nominal detection limits calculated with Milli-Q water. Finally, the method was tested with a pilot study of the Australian population. PE interferences were reduced but still present, and no other polymers were above detection limits. It was concluded that Py-GC-MS is currently not a suitable analysis method for PE and PVC in biological matrices due to the presence of interferences and nonspecific pyrolysis products. Furthermore, while it is plausible to detect some polymers in blood, the estimated exposure concentrations needed are approaching the detection limits of the technique.

Macrophage Responses to Multicore Encapsulated Iron Oxide Nanoparticles for Cancer Therapy

Macrophages are the primary cells responsible for nanoparticle processing and mediating host immunological biological outcomes. Their cellular response to nanoparticles is a vital constituent in the safety assessment of new designs for clinical application. An approach for the treatment of solid tumors was developed, based on magnetic hyperthermia, consisting of iron oxide multicore encapsulated nanoparticles named Sarah nanoparticles (SaNPs), and alternating magnetic field irradiation. SaNPs are intravenously injected, accumulate in the liver, spleen and in tumor tissue, where they are passively targeted to malignant cells via the Enhanced Permeability and Retention (EPR) effect and undergo selective heating. SaNP-induced responses after cellular uptake were investigated in murine RAW264.7 macrophages using a wide imaging approach. When activated, macrophages form different phenotypic populations with unique immune functions, however the mechanism/s by which these activated macrophages respond to nanoparticles is unclear. Unraveling these responses is important for the understanding of nanoparticle uptake, potential degradation, and clearance to address both toxicity and regulatory concerns, which was the aim of this study. The results demonstrated that SaNPs undergo internalization, localize within the lysosomal compartment while keeping their integrity, without intracellular toxic degradation, and are cleared with time. The production of tumor necrosis factor alpha (TNF-α) and reactive oxygen species (ROS), superoxide dismutase (SOD) activation, and cytokine secretion in macrophage conditioned medium (CM) were also evaluated. SaNPs effects were both time- and dose- dependent. High SaNP concentrations resulted in reduced RAW264.7 cell viability which correlated with SOD activation and was associated with ROS generation. Lower SaNP concentrations stimulated the time-dependent production of TNF-α. The expression of additional cytokines was also induced, potentially affecting cancer cell growth by CM from SaNP-activated macrophages supporting a potential antitumor effect. These results will help understand the fate of nanoparticles in vivo.

Zwitterionic Poly(ethylene glycol) Nanoparticles Minimize Protein Adsorption and Immunogenicity for Improved Biological Fate

We report the assembly of poly(ethylene glycol) nanoparticles (PEG NPs) and optimize their surface chemistry to minimize the formation of protein coronas and immunogenicity for improved biodistribution. PEG NPs cross-linked with disulfide bonds are synthesized utilizing zeolitic imidazolate framework-8 NPs as the templates, which are subsequently modified with PEG molecules with different end groups (carboxyl, methoxy, or amino) to vary the surface chemistry. Among the modifications, the amino and residual carboxyl groups form a pair of zwitterionic structures on the surface of PEG NPs, which minimize the adsorption of proteins (e.g., immunoglobulin, complement proteins) and maximize the blood circulation time. The influence of preexisting PEG antibodies in mice on the pharmacokinetics of zwitterionic PEG NPs is negligible, which demonstrates the resistance of anti-PEG antibodies and inhibition of the accelerated blood clearance phenomenon. This research highlights the importance of the surface chemistry of PEGylated NPs in the design of delivery systems and reveals their translational potential for cancer therapy.

Multifunctional Nanomedicine for Targeted Atherosclerosis Therapy: Activating Plaque Clearance Cascade and Suppressing Inflammation

Atherosclerosis (AS) is a prevalent inflammatory vascular disease characterized by plaque formation, primarily composed of foam cells laden with lipids. Despite lipid-lowering therapies, effective plaque clearance remains challenging due to the overexpression of the CD47 molecule on apoptotic foam cells, inhibiting macrophage-mediated cellular efferocytosis and plaque resolution. Moreover, AS lesions are often associated with severe inflammation and oxidative stress, exacerbating disease progression. Herein, we introduce a multifunctional nanomedicine (CEZP) targeting AS pathogenesis via a "cell efferocytosis-lipid degradation-cholesterol efflux" paradigm, with additional anti-inflammatory properties. CEZP comprises poly(lactic-co-glycolic acid) nanoparticles encapsulated within a metal-organic framework shell coordinated with zinc ions (Zn2+) and epigallocatechin gallate (EGCG), enabling CpG encapsulation. Upon intravenous administration, CEZP accumulates at AS plaque sites, facilitating macrophage uptake and orchestrating AS treatment through synergistic mechanisms. CpG enhances cellular efferocytosis, Zn2+ promotes intracellular lipid degradation, and EGCG upregulates adenosine 5'-triphosphate-binding cassette transporters for cholesterol efflux while also exhibiting antioxidant and anti-inflammatory effects. In vivo validation confirms CEZP's ability to stabilize plaques, reduce lipid burden, and modulate the macrophage phenotype. Moreover, CEZP is excreted from the body without safety concerns, offering a low-toxicity nonsurgical strategy for AS plaque eradication.

In Situ and In Vivo Evaluation of Multiplex Protein-Specific Glycosylation of Tumors with a Dual-SERS Encoding Strategy

A dual-SERS encoding strategy was designed for in situ and in vivo evaluation of multiplex protein-specific glycosylation of tumors. The dual-SERS encoding strategy consisted of two pairs of dual gold nanoprobes with different diameters of 10 and 30 nm, which were encoded with four different and distinguishable Raman signal molecules. The 10 and 30 nm gold nanoprobes (Au10 and Au30 probes, respectively) were further modified with lectins and aptamers to recognize the target glycans and proteins, respectively. After sequential binding to the target glycans and proteins, the adjacent Au10 and Au30 probes could emit strong surface-enhanced Raman scattering (SERS) signals to indicate the multiplex protein-specific glycosylation information on cells and in vivo, which can reveal in situ the distribution differences of different tumor markers in the central and marginal regions of tumors. This strategy has been successfully applied for in situ imaging and evaluation of the MUC1 and EpCAM-specific Sia and Gal/GalNAc information on cell surfaces and tumor xenografted mice, providing a convenient and powerful tool to study protein-specific glycosylation-related physiological and pathological mechanisms.

Optimizing Retinal Imaging: Evaluation of ultrasmall TiO2 nanoparticle- fluorescein conjugates for improved Fundus Fluorescein Angiography

Fundus Fluorescein Angiography (FFA) has been extensively used for the identification, management, and diagnosis of various retinal and choroidal diseases, such as age-related macular degeneration, diabetic retinopathy, retinopathy of prematurity, among others. This exam enables clinicians to evaluate retinal morphology and the pathophysiology of retinal vasculature. However, adverse events, including from mild to severe reactions to sodium fluorescein, have been reported. Titanium dioxide nanoparticles (NPTiO2) have shown significant potential in numerous biological applications. Coating or conjugating these nanoparticles with small molecules can enhance their stability, photochemical properties, and biocompatibility, as well as increase the hydrophilicity of the nanoparticles, making them more suitable for biomedical applications. This work demonstrates the potential use of ultrasmall titanium dioxide nanoparticles conjugated with sodium fluorescein to improve the quality of angiography exams. The strategy of conjugating fluorescein with NPTiO2 successfully enhanced the fluorescence photostability of the contrast agent and increased its retention time in the retina. Preliminary in vivo and in vitro safety tests suggest that these nanoparticles are safe for the intended application demonstrating low tendency to hemolysis, and no significant changes in the retina thickness or in the electroretinography a-wave and b-wave amplitudes. Overall, the conjugation of fluorescein to NPTiO2 has produced a nanomaterial with favorable properties for use as an innovative contrast agent in FFA examinations. By providing a clear description of our methodology of analysis, we also aim to offer better perspectives and reproducible conditions for future research.

Recent Advances in NIR or X-ray Excited Persistent Luminescent Materials for Deep Bioimaging

Due to their persistent luminescence, persistent luminescent (PersL) materials have attracted great interest. In the biomedical field, the use of persistent luminescent nanoparticles (PLNPs) eliminates the need for continuous in situ excitation, thereby avoiding interference from tissue autofluorescence and significantly improving the signal-to-noise ratio (SNR). Although persistent luminescence materials can emit light continuously, the luminescence intensity of small-sized nanoparticles in vivo decays quickly. Early persistent luminescent nanoparticles were mostly excited by ultraviolet (UV) or visible light and were administered for imaging purposes through ex vivo charging followed by injection into the body. Limited by the low in vivo penetration depth, UV light cannot secondary charge PLNPs that have decayed in vivo, and visible light does not penetrate deep enough to reach deep tissues, which greatly limits the imaging time of persistent luminescent materials. In order to address this issue, the development of PLNPs that can be activated by light sources with superior tissue penetration capabilities is essential. Near-infrared (NIR) light and X-rays are widely recognized as ideal excitation sources, making persistent luminescent materials stimulated by these two sources a prominent area of research in recent years. This review describes NIR and X-ray excitable persistent luminescence materials and their recent advances in bioimaging.

Ultrasound nanodroplets loaded with Siglec-G siRNA and Fe3O4 activate macrophages and enhance phagocytosis for immunotherapy of triple-negative breast cancer

BACKGROUND

The progression of triple-negative breast cancer is shaped by both tumor cells and the surrounding tumor microenvironment (TME). Within the TME, tumor-associated macrophages (TAMs) represent a significant cell population and have emerged as a primary target for cancer therapy. As antigen-presenting cells within the innate immune system, macrophages are pivotal in tumor immunotherapy through their phagocytic functions. Due to the highly dynamic and heterogeneous nature of TAMs, re-polarizing them to the anti-tumor M1 phenotype can amplify anti-tumor effects and help mitigate the immunosuppressive TME.

RESULTS

In this study, we designed and constructed an ultrasound-responsive targeted nanodrug delivery system to deliver Siglec-G siRNA and Fe3O4, with perfluorohexane (PFH) at the core and mannose modified on the surface (referred to as MPFS@NDs). Siglec-G siRNA blocks the CD24/Siglec-G mediated "don't eat me" phagocytosis inhibition pathway, activating macrophages, enhancing their phagocytic function, and improving antigen presentation, subsequently triggering anti-tumor immune responses. Fe3O4 repolarizes M2-TAMs to the anti-tumor M1 phenotype. Together, these components synergistically alleviate the immunosuppressive TME, and promote T cell activation, proliferation, and recruitment to tumor tissues, effectively inhibiting the growth of primary tumors and lung metastasis.

CONCLUSION

This work suggests that activating macrophages and enhancing phagocytosis to remodel the TME could be an effective strategy for macrophage-based triple-negative breast cancer immunotherapy.

Shedding light on vascular imaging: the revolutionary role of nanotechnology

Vascular dysfunction, characterized by changes in anatomy, hemodynamics, and molecular expressions of vasculatures, is closely linked to the onset and development of diseases, emphasizing the importance of its detection. In clinical practice, medical imaging has been utilized as a significant tool in the assessment of vascular dysfunction, however, traditional imaging techniques still lack sufficient resolution for visualizing the complex microvascular systems. Over the past decade, with the rapid advancement of nanotechnology and the emergence of corresponding detection facilities, engineered nanomaterials offer new alternatives to traditional contrast agents. Compared with conventional small molecule counterparts, nanomaterials possess numerous advantages for vascular imaging, holding the potential to significantly advance related technologies. In this review, the latest developments in nanotechnology-assisted vascular imaging research across different imaging modalities, including contrast-enhanced magnetic resonance (MR) angiography, susceptibility-weighted imaging (SWI), and fluorescence imaging in the second near-infrared window (NIR-II) are summarized. Additionally, the advancements of preclinical and clinical studies related to these nanotechnology-enhanced vascular imaging approaches are outlined, with subsequent discussion on the current challenges and future prospects in both basic research and clinical translation.

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.

Investigation of pharmacokinetics and immunogenicity of magnetosomes

Magnetosomes are iron oxide or iron sulphide nano-sized particles surrounded by a lipid bilayer synthesised by a group of bacteria known as magnetotactic bacteria (MTB). Magnetosomes have become a promising candidate for biomedical applications and could be potentially used as a drug-carrier. However, pharmacokinetics and immunogenicity of the magnetosomes have not been understood yet which preclude its clinical applications. Herein, we investigated the pharmacokinetics of magnetosomes including Absorption, Distribution, Metabolism, and Elimination (ADME) along with its immunogenicity in vitro and in vivo. The magnetosomes were conjugated with fluorescein isothiocyanate (Mag-FITC) and their conjugation was confirmed through fluorescence microscopy and its absorption in HeLa cell lines was evaluated using flow cytometry analysis. The results revealed a maximum cell uptake of 97% at 200 µg/mL concentration. Further, the biodistribution of Mag-FITC was investigated in vivo by a bioimaging system using BALB/c mice as a subject at different time intervals. The Mag-FITC neither induced death nor physical distress and the same was eliminated post 36 h of injection with meagre intensities left behind. The metabolism and elimination analysis were assessed to detect the iron overload which revealed that magnetosomes were entirely metabolised within 48-h interval. Furthermore, the histopathology and serum analysis reveal no histological damage with the absence of any abnormal biochemical parameters. The results support our study that magnetosomes were completely removed from the blood circulation within 48-h time interval. Moreover, the immunogenicity analysis has shown that magnetosomes do not induce any inflammation as indicated by reduced peaks of immune markers such as IL 1β, IL 2, IL 6, IL8, IFN γ, and TNF α estimated through Indirect ELISA. The normal behaviour of animals with the absence of acute or chronic toxicities in any organs declares that magnetosomes are safe to be injected. This shows that magnetosomes are benign for biological systems enrouting towards beneficial biomedical applications. Therefore, this study will advance the understanding and application of magnetosomes for clinical purposes.

Navigating the intricate in-vivo journey of lipid nanoparticles tailored for the targeted delivery of RNA therapeutics: a quality-by-design approach

RNA therapeutics, such as mRNA, siRNA, and CRISPR-Cas9, present exciting avenues for treating diverse diseases. However, their potential is commonly hindered by vulnerability to degradation and poor cellular uptake, requiring effective delivery systems. Lipid nanoparticles (LNPs) have emerged as a leading choice for in vivo RNA delivery, offering protection against degradation, enhanced cellular uptake, and facilitation of endosomal escape. However, LNPs encounter numerous challenges for targeted RNA delivery in vivo, demanding advanced particle engineering, surface functionalization with targeting ligands, and a profound comprehension of the biological milieu in which they function. This review explores the structural and physicochemical characteristics of LNPs, in-vivo fate, and customization for RNA therapeutics. We highlight the quality-by-design (QbD) approach for targeted delivery beyond the liver, focusing on biodistribution, immunogenicity, and toxicity. In addition, we explored the current challenges and strategies associated with LNPs for in-vivo RNA delivery, such as ensuring repeated-dose efficacy, safety, and tissue-specific gene delivery. Furthermore, we provide insights into the current clinical applications in various classes of diseases and finally prospects of LNPs in RNA therapeutics.

Pharmacokinetics and fate of free and encapsulated IRD800CW-labelled human BChE intravenously administered in mice

Human butyrylcholinesterase (BChE) is an efficient bioscavenger of toxicants. Highly purified BChE was labelled with the near infrared fluorescent IRDye800CW. The goal was to determine the pharmacokinetics and fate of enzyme in mice. BChE-IRDye800CW was encapsulated in polyethylene glycol-polypropylene sulfide-based spherical polymersome nanoreactors with the following characteristics: 140 nm diameter, ξ = -6 mV, PDI ≤ 0.2, 1 year stability. Encapsulation did not alter the functional properties of BChE. Free and encapsulated enzyme were injected intravenously to CD-1 mice (single dose of enzyme 1.5 mg/kg and PEG-PPS polymersomes 25 mg/kg) and were analyzed for 8 days using an in vivo imaging system. Results showed that the pharmacokinetic distribution α-phase of encapsulated BChE (t1/2 = 17.6 h) was longer than for free enzyme (t1/2 = 6.6 h). The mean half-time for elimination β-phase was 2-time longer for encapsulated enzyme than for free enzyme (150 vs 72 h). Transient changes in infrared fluorescence in organs showed that BChE is eliminated from liver. However, free and encapsulated enzymes were cleared via different pathways. This first study of pharmacokinetics and fate of BChE encapsulated in polymersomes initiates research of new formulations of bioscavengers aimed at increasing the residence time of enzymes in the blood stream.

Affibody-Functionalized Elastin-like Peptide-Drug Conjugate Nanomicelle for Targeted Ovarian Cancer Therapy

Recombinant elastin-like polypeptides (ELPs) have emerged as an attractive nanoplatform for drug delivery due to their tunable genetically encoded sequence, biocompatibility, and stimuli-responsive self-assembly behaviors. Here, we designed and biosynthesized an HER2 (human epidermal growth factor receptor 2)-targeted affibody-ELP fusion protein (Z-ELP), which was subsequently conjugated with monomethyl auristatin E (MMAE) to build a protein-drug conjugate (Z-ELP-M). Due to its thermal response, Z-ELP-M can immediately self-assemble into a nanomicelle at physiological temperature. Benefiting from its active targeting and nanomorphology, Z-ELP-M exhibits enhanced cellular internalization and deep tumor penetration in vitro. Moreover, Z-ELP-M shows excellent tumor targeting and superior antitumor efficacy in HER2-positive ovarian cancer, demonstrating a relative tumor growth inhibition of 104.6%. These findings suggest that an affibody-functionalized elastin-like peptide-drug conjugate nanomicelle is an efficient strategy to improve antitumor efficacy and biosafety in cancer therapy.

Liposome biodistribution mapping with in vivo X-ray fluorescence imaging

Lipid-based nanoparticles are organic nanostructures constituted of phospholipids and cholesterol, displaying high in vivo biocompatibility. They have been demonstrated as effective nanocarriers for drug delivery and targeting. Mapping liposome distribution is crucial as it enables a precise understanding of delivery kinetics, tissue targeting efficiency, and potential off-target effects. Recently, ruthenium-encapsulated liposomes have shown potential for targeted drug delivery, photodynamic therapy, and optical fluorescence imaging. In the present work, we design Ru(bpy)3-encapsulated liposomes (Ru-Lipo) empowering optical and X-ray fluorescence (XRF) properties for dual mode imaging and demonstrate the passivation role of liposomes over the free Ru(bpy)3 compound. We employ whole-body XRF imaging to map the in vivo biodistribution of Ru-Lipo in mice, enabling tumor detection and longitudinal studies with elemental specificity and resolution down to the sub-millimeter scale. Quantitative XRF computed tomography on extracted organs permits targeting efficiency evaluations. These findings highlight the promising role of XRF imaging in pharmacokinetic studies and theranostic applications for the rapid optimization of drug delivery and assessment of targeting efficiency.

Selective Transfection of a Transferrin Receptor-Expressing Cell Line with DNA-Lipid Nanoparticles

Despite considerable progress in using lipid nanoparticle (LNP) vehicles for gene delivery, achieving selective transfection of specific cell types remains a significant challenge, hindering the advancement of new gene or gene-editing therapies. Although LNPs have been equipped with ligands aimed at targeting specific cellular receptors, achieving complete selectivity continues to be elusive. The exact reasons for this limited selectivity are not fully understood, as cell targeting involves a complex interplay of various cellular factors. Assessing how much ligand/receptor binding contributes to selectivity is challenging due to these additional influencing factors. Nonetheless, such data are important for developing new nanocarriers and setting realistic expectations for selectivity. Here, we have quantified the selective, targeted transfection using two uniquely engineered cell lines that eliminate unpredictable and interfering cellular influences. We have compared the targeted transfection of Chinese ovary hamster (CHO) cells engineered to express the human transferrin receptor 1 (hTfR1), CHO-TRVb-hTfR1, with CHO cells that completely lack any transferrin receptor, CHO-TRVb-neo cells (negative control). Thus, the two cell lines differ only in the presence/absence of hTfR1. The transfection was performed with pDNA-encapsulating LNPs equipped with the DT7 peptide ligand that specifically binds to hTfR1 and enables targeted transfection. The LNP's pDNA encoded for the monomeric GreenLantern (mGL) reporter protein, whose fluorescence was used to quantify transfection. We report a novel LNP composition designed to achieve an optimal particle size and ζ-potential, efficient pDNA encapsulation, hTfR1-targeting capability, and sufficient polyethylene glycol sheltering to minimize random cell targeting. The transfection efficiency was quantified in both cell lines separately through flow cytometry based on the expression of the fluorescent gene product. Our results demonstrated an LNP dose-dependent mGL expression, with a 5-fold preference for the CHO-TRVb-hTfR1 when compared to CHO-TRVb-neo. In another experiment, when both cell lines were mixed at a 1:1 ratio, the DT7-decorated LNP achieved a 3-fold higher transfection of the CHO-TRVb-hTfR1 over the CHO-TRVb-neo cells. Based on the low-level transfection of the CHO-TRVb-neo cells in both experiments, our results suggest that 17-25% of the transfection occurred in a nonspecific manner. The observed transfection selectivity for the CHO-TRVb-hTfR1 cells was based entirely on the hTfR1/DT7 interaction. This work showed that the platform of two engineered cell lines which differ only in the hTfR1 can greatly facilitate the development of LNPs with hTfR1-targeting ligands.

Elimination study of intact lipid nanocapsules after intravenous rat administration

Aim: The present study investigated renal elimination after intravenous administration of four different formulations of lipid nanocapsules (LNCs) containing dyes adapted to Förster resonance energy transfer (FRET-LNCs).Materials & methods: FRET-LNCs of 85 or 50 nm with or without a pegylated surface were injected and collected in the blood or urine of rats at different time points. Quantitative analysis was performed to measure intact FRET-LNCs.Results & conclusion: No intact LNCs were found in urine (0 particles/ml) for all formulations. The 50-nm pegylated LNCs were eliminated faster from the blood, whereas 85-nm pegylated LNCS were eliminated slower than nonpegylated LNCs. Elimination of FRET-LNCs was mainly due to liver tissue interaction and not renal elimination.

Ellagic acid-enhanced biocompatibility and bioactivity in multilayer core-shell gold nanoparticles for ameliorating myocardial infarction injury

BACKGROUND

Myocardial infarction (MI) is the main contributor to most cardiovascular diseases (CVDs), and the available post-treatment clinical therapeutic options are limited. The development of nanoscale drug delivery systems carrying natural small molecules provides biotherapies that could potentially offer new treatments for reactive oxygen species (ROS)-induced damage in MI. Considering the stability and reduced toxicity of gold-phenolic core-shell nanoparticles, this study aims to develop ellagic acid-functionalized gold nanoparticles (EA-AuNPs) to overcome these limitations.

RESULTS

We have successfully synthesized EA-AuNPs with enhanced biocompatibility and bioactivity. These core-shell gold nanoparticles exhibit excellent ROS-scavenging activity and high dispersion. The results from a label-free imaging method on optically transparent zebrafish larvae models and micro-CT imaging in mice indicated that EA-AuNPs enable a favorable excretion-based metabolism without overburdening other organs. EA-AuNPs were subsequently applied in cellular oxidative stress models and MI mouse models. We found that they effectively inhibit the expression of apoptosis-related proteins and the elevation of cardiac enzyme activities, thereby ameliorating oxidative stress injuries in MI mice. Further investigations of oxylipin profiles indicated that EA-AuNPs might alleviate myocardial injury by inhibiting ROS-induced oxylipin level alterations, restoring the perturbed anti-inflammatory oxylipins.

CONCLUSIONS

These findings collectively emphasized the protective role of EA-AuNPs in myocardial injury, which contributes to the development of innovative gold-phenolic nanoparticles and further advances their potential medical applications.

Apoptotic vesicles (apoVs) derived from fibroblast-converted hepatocyte-like cells effectively ameliorate liver fibrosis

Liver fibrosis is a serious global health issue for which effective treatment remains elusive. Chemical-induced hepatocyte-like cells (ciHeps) have emerged as an appealing source for cell transplantation therapy, although they present several challenges such as the risk of lung thromboembolism or hemorrhage. Apoptotic vesicles (apoVs), small membrane vesicles generated during the apoptosis process, have gained attention for their role in regulating various physiological and pathological processes. In this study, we generated ciHep-derived apoVs (ciHep-apoVs) and investigated their therapeutic potential in alleviating liver fibrosis. Our findings revealed that ciHep-apoVs induced the transformation of macrophages into an anti-inflammatory phenotype, effectively suppressed the activity of activated hepatic stellate cells (aHSCs), and enhanced the survival of hepatocytes. When intravenously administered to mice with liver fibrosis, ciHep-apoVs were primarily engulfed by macrophages and myofibroblasts, leading to a reduction in liver inflammation and fibrosis. Proteomic and miRNA analyses showed that ciHep-apoVs were enriched in various functional molecules that modulate crucial cellular processes, including metabolism, signaling transduction, and ECM-receptor interactions. ciHep-apoVs effectively suppressed aHSCs activity through the synergistic inhibition of glycolysis, the PI3K/AKT/mTOR pathway, and epithelial-to-mesenchymal transition (EMT) cascades. These findings highlight the potential of ciHep-apoVs as multifunctional nanotherapeutics for liver fibrosis and provide insights into the treatment of other liver diseases and fibrosis in other organs.

Hepatic Biotransformation of Renal Clearable Gold Nanoparticles for Noninvasive Detection of Liver Glutathione Level via Urinalysis

Renal clearable nanoparticles have been drawing much attention as they can avoid prolonged accumulation in the body by efficiently clearing through the kidneys. While much effort has been made to understand their interactions within the kidneys, it remains unclear whether their transport could be influenced by other organs, such as the liver, which plays a crucial role in metabolizing and eliminating both endogenous and exogenous substances through various biotransformation processes. Here, by utilizing renal clearable IRDye800CW conjugated gold nanocluster (800CW4-GS18-Au25) as a model, we found that although 800CW4-GS18-Au25 strongly resisted serum-protein binding and exhibited minimal accumulation in the liver, its surface was still gradually modified by hepatic glutathione-mediated biotransformation when passing through the liver, resulting in the dissociation of IRDye800CW from Au25 and biotransformation-generated fingerprint message of 800CW4-GS18-Au25 in urine, which allowed us to facilely quantify its urinary biotransformation index (UBI) via urine chromatography analysis. Moreover, we observed the linear correlation between UBI and hepatic glutathione concentration, offering us a noninvasive method for quantitative detection of liver glutathione level through a simple urine test. Our discoveries would broaden the fundamental understanding of in vivo transport of nanoparticles and advance the development of urinary probes for noninvasive biodetection.

Use of parvovirus B19-like particles in self-illuminated photodynamic therapy for solid tumors

Bioluminescence resonance energy transfer photodynamic therapy, which uses light generated by bioluminescent proteins to activate photosensitizers and produce reactive oxygen species without the need for external irradiation, has shown promising results in cancer models. However, the characterization of delivery systems that can incorporate the components of this therapy for preferential delivery to the tumor remains necessary. In this work, we have characterized parvovirus B19-like particles (B19V-VLPs) as a platform for a photosensitizer and a bioluminescent protein. By chemical and biorthogonal conjugation, we conjugated rose Bengal photosensitizer and firefly luciferase to B19V-VLPs and a protein for added specificity. The results showed that B19V-VLPs can withstand decoration with all three components without affecting its structure or stability. The conjugated luciferase showed activity and was able to activate rose Bengal to produce singlet oxygen without the need for external light. The photodynamic reaction generated by the functionalized VLPs-B19 can decrease the viability of tumor cells in vitro and affect tumor growth and metastasis in the 4 T1 model. Treatment with functionalized VLPs-B19 also increased the percentage of CD4 and CD8 cell populations in the spleen and in inguinal lymph nodes compared to vehicle-treated mice. Our results support B19V-VLPs as a delivery platform for bioluminescent photodynamic therapy components to solid tumors.

Modifying the Backbone Chemistry of PEG-Based Bottlebrush Block Copolymers for the Formation of Long-Circulating Nanoparticles

Nanoparticle physicochemical properties have received great attention in optimizing the performance of nanoparticles for biomedical applications. For example, surface functionalization with small molecules or linear hydrophilic polymers is commonly used to tune the interaction of nanoparticles with proteins and cells. However, it is challenging to control the location of functional groups within the shell for conventional nanoparticles. Nanoparticle surfaces composed of shape-persistent bottlebrush polymers allow hierarchical control over the nanoparticle shell but the effect of the bottlebrush backbone on biological interactions is still unknown. The synthesis is reported of novel heterobifunctional poly(ethylene glycol) (PEG)-norbornene macromonomers modified with various small molecules to form bottlebrush polymers with different backbone chemistries. It is demonstrated that micellar nanoparticles composed of poly(lactic acid) (PLA)-PEG bottlebrush block copolymer (BBCP) with neutral and cationic backbone modifications exhibit significantly reduced cellular uptake compared to conventional unmodified BBCPs. Furthermore, the nanoparticles display long blood circulation half-lives of ≈22 hours and enhanced tumor accumulation in mice. Overall, this work sheds light on the importance of the bottlebrush polymer backbone and provides a strategy to improve the performance of nanoparticles in biomedical applications.

Lipid Nanoparticles for Nucleic Acid Delivery Beyond the Liver

Lipid nanoparticles (LNPs) are the most clinically advanced drug delivery system for nucleic acid therapeutics, exemplified by the success of the COVID-19 mRNA vaccines. However, their clinical use is currently limited to hepatic diseases and vaccines due to their tendency to accumulate in the liver upon intravenous administration. To fully leverage their potential, it is essential to understand and address their liver tropism, while also developing strategies to enhance delivery to tissues beyond the liver. Ensuring that these therapeutics reach their target cells while avoiding off-target cells is essential for both their efficacy and safety. There are three potential targeting strategies-passive, active, and endogenous-which can be used individually or in combination to target nonhepatic tissues. In this review, we delve into the recent advancements in LNP engineering for delivering nucleic acid beyond the liver.

Targeted SERS Imaging and Intraoperative Real-Time Elimination of Microscopic Tumors for Improved Breast-Conserving Surgery

Breast-conserving surgery is the favorable option for breast cancer patients owing to its advantages of less aggressiveness and better cosmetic outcomes over mastectomy. However, it often suffers from postsurgical lethal recurrence due to the incomplete removal of microscopic tumors. Here, a surface-enhanced Raman scattering (SERS) surgical strategy is reported for precise delineation of tumor margins and intraoperative real-time elimination of microscopic tumor foci, which is capable of complete surgical removal of breast tumors and significantly improve the outcomes of breast-conserving surgery without local tumor recurrence. The technique is chiefly based on the human epidermal growth factor receptor 2 (HER2)-targeting SERS probes with integrated multifunctionalities of ultrahigh sensitive detection, significant HER2 expression suppression, cell proliferation inhibition, and superior photothermal ablation. In a HER2+ breast tumor mouse model, the remarkable capability of the SERS surgical strategy for complete removal of HER2+ breast tumors through SERS-guided surgical resection and intraoperative real-time photothermal elimination is demonstrated. The results show complete eradiation of HER2+ breast tumors without local recurrence, consequently delivering a 100% tumor-free survival. Expectedly, this SERS surgical strategy holds great promise for clinical treatment of HER2+ breast cancer with improved patients' survival.

Tumor Cell-Derived Exosomal Hybrid Nanosystems Loaded with Rhubarbic Acid and Tanshinone IIA for Sepsis Treatment

Background

Sepsis continues to exert a significant impact on morbidity and mortality in clinical settings, with immunosuppression, multi-organ failure, and disruptions in gut microbiota being key features. Although rheinic acid and tanshinone IIA show promise in mitigating macrophage apoptosis in sepsis treatment, their precise targeting of macrophages remains limited. Additionally, the evaluation of intestinal flora changes following treatment, which plays a significant role in subsequent cytokine storms, has been overlooked. Leveraging the innate inflammation chemotaxis of tumor cell-derived exosomes allows for their rapid recognition and uptake by activated macrophages, facilitating phenotypic changes and harnessing anti-inflammatory effects.

Methods

We extracted exosomes from H1299 cells using a precipitation method. Then we developed a tumor cell-derived exosomal hybrid nanosystem loaded with rhubarbic acid and tanshinone IIA (R+T/Lipo/EXO) for sepsis treatment. In vitro studies, we verify the anti-inflammatory effect and the mechanism of inhibiting cell apoptosis of nano drug delivery system. The anti-inflammatory effects, safety, and modulation of intestinal microbiota by the nanoformulations were further validated in the in vivo study.

Results

Nanoformulation demonstrated enhanced macrophage internalization, reduced TNF-α expression, inhibited apoptosis, modulated intestinal flora, and alleviated immunosuppression.

Conclusion

R+T/Lipo/EXO presents a promising approach using exosomal hybrid nanosystems for treating sepsis.

Kupffer cells determine intrahepatic traffic of PEGylated liposomal doxorubicin

Intrahepatic accumulation dominates organ distribution for most nanomedicines. However, obscure intrahepatic fate largely hampers regulation on their in vivo performance. Herein, PEGylated liposomal doxorubicin is exploited to clarify the intrahepatic fate of both liposomes and the payload in male mice. Kupffer cells initiate and dominate intrahepatic capture of liposomal doxorubicin, following to deliver released doxorubicin to hepatocytes with zonated distribution along the lobule porto-central axis. Increasing Kupffer cells capture promotes doxorubicin accumulation in hepatocytes, revealing the Kupffer cells capture-payload release-hepatocytes accumulation scheme. In contrast, free doxorubicin is overlooked by Kupffer cells, instead quickly distributing into hepatocytes by directly crossing fenestrated liver sinusoid endothelium. Compared to free doxorubicin, liposomal doxorubicin exhibits sustained metabolism/excretion due to the extra capture-release process. This work unveils the pivotal role of Kupffer cells in intrahepatic traffic of PEGylated liposomal therapeutics, and quantitively describes the intrahepatic transport/distribution/elimination process, providing crucial information for guiding further development of nanomedicines.

Suborgan Level Quantitation of Proteins in Tissues Delivered by Polymeric Nanocarriers

Amidst the rapid growth of protein therapeutics as a drug class, there is an increased focus on designing systems to effectively deliver proteins to target organs. Quantitative monitoring of protein distributions in tissues is essential for optimal development of delivery systems; however, existing strategies can have limited accuracy, making it difficult to assess suborgan dosing. Here, we describe a quantitative imaging approach that utilizes metal-coded mass tags and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to quantify the suborgan distributions of proteins in tissues that have been delivered by polymeric nanocarriers. Using this approach, we measure nanomole per gram levels of proteins as delivered by guanidinium-functionalized poly(oxanorborneneimide) (PONI) polymers to various tissues, including the alveolar region of the lung. Due to the multiplexing capability of the LA-ICP-MS imaging, we are also able to simultaneously quantify protein and polymer distributions, obtaining valuable information about the relative excretion pathways of the protein cargo and carrier. This imaging approach will facilitate quantitative correlations between nanocarrier properties and protein cargo biodistributions.

Truly Tiny Acoustic Biomolecules for Ultrasound Imaging and Therapy

Nanotechnology offers significant advantages for medical imaging and therapy, including enhanced contrast and precision targeting. However, integrating these benefits into ultrasonography is challenging due to the size and stability constraints of conventional bubble-based agents. Here bicones, truly tiny acoustic contrast agents based on gas vesicles (GVs), a unique class of air-filled protein nanostructures naturally produced in buoyant microbes, are described. It is shown that these sub-80 nm particles can be effectively detected both in vitro and in vivo, infiltrate tumors via leaky vasculature, deliver potent mechanical effects through ultrasound-induced inertial cavitation, and are easily engineered for molecular targeting, prolonged circulation time, and payload conjugation.

In vivo biodistribution and tumor uptake of [64Cu]-FAU nanozeolite via positron emission tomography Imaging

Nanoparticles have emerged as promising theranostic tools for biomedical applications, notably in the treatment of cancers. However, to fully exploit their potential, a thorough understanding of their biodistribution is imperative. In this context, we prepared radioactive [64Cu]-exchanged faujasite nanosized zeolite ([64Cu]-FAU) to conduct positron emission tomography (PET) imaging tracking in preclinical glioblastoma models. In vivo results revealed a rapid and gradual accumulation over time of intravenously injected [64Cu]-FAU zeolite nanocrystals within the brain tumor, while no uptake in the healthy brain was observed. Although a specific tumor targeting was observed in the brain, the kinetics of uptake into tumor tissue was found to be dependent on the glioblastoma model. Indeed, our results showed a rapid uptake in U87-MG model while in U251-MG glioblastoma model tumor uptake was gradual over the time. Interestingly, a [64Cu] activity, decreasing over time, was also observed in organs of elimination such as kidney and liver without showing a difference in activity between both glioblastoma models. Ex vivo analyses confirmed the presence of zeolite nanocrystals in brain tumor with detection of both Si and Al elements originated from them. This radiolabelling strategy, performed for the first time using nanozeolites, enables precise tracking through PET imaging and confirms their accumulation within the glioblastoma. These findings further bolster the potential use of zeolite nanocrystals as valuable theranostic tools.

Mitochondrial Targeted Cerium Oxide Nanoclusters for Radiation Protection and Promoting Hematopoiesis

Purpose

Mitochondrial oxidative stress is an important factor in cell apoptosis. Cerium oxide nanomaterials show great potential for scavenging free radicals and simulating superoxide dismutase (SOD) and catalase (CAT) activities. To solve the problem of poor targeting of cerium oxide nanomaterials, we designed albumin-cerium oxide nanoclusters (TPP-PCNLs) that target the modification of mitochondria with triphenyl phosphate (TPP). TPP-PCNLs are expected to simulate the activity of superoxide dismutase, continuously remove reactive oxygen species, and play a lasting role in radiation protection.

Methods

First, cerium dioxide nanoclusters (CNLs), polyethylene glycol cerium dioxide nanoclusters (PCNLs), and TPP-PCNLs were characterized in terms of their morphology and size, ultraviolet spectrum, dispersion stability and cellular uptake, and colocalization Subsequently, the anti-radiation effects of TPP-PCNLs were investigated using in vitro and in vivo experiments including cell viability, apoptosis, comet assays, histopathology, and dose reduction factor (DRF).

Results

TPP-PCNLs exhibited good stability and biocompatibility. In vitro experiments indicated that TPP-PCNLs could not only target mitochondria excellently but also regulate reactive oxygen species (ROS)levels in whole cells. More importantly, TPP-PCNLs improved the integrity and functionality of mitochondria in irradiated L-02 cells, thereby indirectly eliminating the continuous damage to nuclear DNA caused by mitochondrial oxidative stress. TPP-PCNLs are mainly targeted to the liver, spleen, and other extramedullary hematopoietic organs with a radiation dose reduction factor of 1.30. In vivo experiments showed that TPP-PCNLs effectively improved the survival rate, weight change, hematopoietic function of irradiated animals. Western blot experiments have confirmed that TPP-PCNLs play a role in radiation protection by regulating the mitochondrial apoptotic pathway.

Conclusion

TPP-PCNLs play a radiologically protective role by targeting extramedullary hematopoietic organ-liver cells and mitochondria to continuously clear ROS.

Unveiling Nanoparticles: Recent Approaches in Studying the Internalization Pattern of Iron Oxide Nanoparticles in Mono- and Multicellular Biological Structures

Nanoparticle (NP)-based solutions for oncotherapy promise an improved efficiency of the anticancer response, as well as higher comfort for the patient. The current advancements in cancer treatment based on nanotechnology exploit the ability of these systems to pass biological barriers to target the tumor cell, as well as tumor cell organelles. In particular, iron oxide NPs are being clinically employed in oncological management due to this ability. When designing an efficient anti-cancer therapy based on NPs, it is important to know and to modulate the phenomena which take place during the interaction of the NPs with the tumor cells, as well as the normal tissues. In this regard, our review is focused on highlighting different approaches to studying the internalization patterns of iron oxide NPs in simple and complex 2D and 3D in vitro cell models, as well as in living tissues, in order to investigate the functionality of an NP-based treatment.

Autophagy and mitophagy as potential therapeutic targets in diabetic heart condition: Harnessing the power of nanotheranostics

Autophagy and mitophagy pose unresolved challenges in understanding the pathology of diabetic heart condition (DHC), which encompasses a complex range of cardiovascular issues linked to diabetes and associated cardiomyopathies. Despite significant progress in reducing mortality rates from cardiovascular diseases (CVDs), heart failure remains a major cause of increased morbidity among diabetic patients. These cellular processes are essential for maintaining cellular balance and removing damaged or dysfunctional components, and their involvement in the development of diabetic heart disease makes them attractive targets for diagnosis and treatment. While a variety of conventional diagnostic and therapeutic strategies are available, DHC continues to present a significant challenge. Point-of-care diagnostics, supported by nanobiosensing techniques, offer a promising alternative for these complex scenarios. Although conventional medications have been widely used in DHC patients, they raise several concerns regarding various physiological aspects. Modern medicine places great emphasis on the application of nanotechnology to target autophagy and mitophagy in DHC, offering a promising approach to deliver drugs beyond the limitations of traditional therapies. This article aims to explore the potential connections between autophagy, mitophagy and DHC, while also discussing the promise of nanotechnology-based theranostic interventions that specifically target these molecular pathways.

Targeted delivery strategies: The interactions and applications of nanoparticles in liver diseases

In recent years, nanoparticles have been broadly utilized in various drugs delivery formulations. Nanodelivery systems have shown promise in solving problems associated with the distribution of hydrophobic drugs and have promoted the accumulation of nanomedicines in the circulation or in organs. However, the injection dose of nanoparticles (NPs) is much greater than that needed by diseased tissues or organs. In other words, most of the NPs are localized off-target and do not reach the desired tissue or organs. With the rapid development of biodegradable and biosafety nanomaterials, the nanovectors represent assurance of safety. However, the off-target effects also induce concerns about the application of NPs, especially in the delivery of gene editing tools. Therefore, a complete understanding of the biological responses to NPs in the body will clearly guide the design of targeted delivery of NPs. The different properties of various nanodelivery systems may induce diverse interactions between carriers and organs. In this review, we describe the relationship between the liver, the most influenced organ of systemic administration of NPs, and targeted delivery nanoplatforms. Various transport vehicles have adopted multiple delivery strategies for the targeted delivery to the cells in the homeostasis liver and in diseased liver. Additionally, nanodelivery systems provide a novel strategy for treating incurable diseases. The appearance of a targeted delivery has profoundly improved the application of NPs to liver diseases.

Understanding nanoparticle-liver interactions in nanomedicine

INTRODUCTION

Understanding the interactions between administered nanoparticles and the liver is crucial for developing safe and effective nanomedicines. As the liver can sequester up to 99% of these particles due to its major phagocytic role, understanding these interactions is vital for clinical translation.

AREAS COVERED

This review highlights recent studies on nanoparticle-liver interactions, including the influence of nanoparticle physicochemical properties on delivery, strategies to enhance delivery efficiency by modulating liver Kupffer cells, and their potential for treating certain hepatic diseases. Additionally, we discuss how aging impacts the liver's phagocytic functions.

EXPERT OPINION

While liver accumulation can hinder nanomedicine safety and effectiveness, it also presents opportunities for treating certain liver diseases. A thorough understanding of nanoparticle-liver interactions is essential for advancing the clinical application of nanomedicines.

Uniform trehalose nanogels for glucagon stabilization

Glucagon is a peptide hormone that acts via receptor-mediated signaling predominantly in the liver to raise glucose levels by hepatic glycogen breakdown or conversion of noncarbohydrate, 3 carbon precursors to glucose by gluconeogenesis. Glucagon is administered to reverse severe hypoglycemia, a clinical complication associated with type 1 diabetes. However, due to low stability and solubility at neutral pH, there are limitations in the current formulations of glucagon. Trehalose methacrylate-based nanoparticles were utilized as the stabilizing and solubilizing moiety in the system reported herein. Glucagon was site-selectively modified to contain a cysteine at amino acid number 24 to covalently attach to the methacrylate-based polymer containing pyridyl disulfide side chains. PEG2000 dithiol was employed as the crosslinker to form uniform nanoparticles. Glucagon nanogels were monitored in Dulbecco's phosphate-buffered saline (DPBS) pH 7.4 at various temperatures to determine its long-term stability in solution. Glucagon nanogels were stable up to at least 5 months by size uniformity when stored at -20 °C and 4 °C, up to 5 days at 25 °C, and less than 12 hours at 37 °C. When glucagon stability was studied by either HPLC or thioflavin T assays, the glucagon was intact for at least 5 months at -20 °C and 4 °C within the nanoparticles at -20 °C and 4 °C and up to 2 days at 25 °C. Additionally, the glucagon nanogels were studied for toxicity and efficacy using various assays in vitro. The findings indicate that the nanogels were nontoxic to fibroblast cells and nonhemolytic to red blood cells. The glucagon in the nanogels was as active as glucagon alone. These results demonstrate the utility of trehalose nanogels towards a glucagon formulation with improved stability and solubility in aqueous solutions, particularly useful for storage at cold temperatures.

Surface ligand-regulated renal clearance of MRI/SPECT dual-modality nanoprobes for tumor imaging

BACKGROUND

The general sluggish clearance kinetics of functional inorganic nanoparticles tend to raise potential biosafety concerns for in vivo applications. Renal clearance is a possible elimination pathway for functional inorganic nanoparticles delivered through intravenous injection, but largely depending on the surface physical chemical properties of a given particle apart from its size and shape.

RESULTS

In this study, three small-molecule ligands that bear a diphosphonate (DP) group, but different terminal groups on the other side, i.e., anionic, cationic, and zwitterionic groups, were synthesized and used to modify ultrasmall Fe3O4 nanoparticles for evaluating the surface structure-dependent renal clearance behaviors. Systematic studies suggested that the variation of the surface ligands did not significantly increase the hydrodynamic diameter of ultrasmall Fe3O4 nanoparticles, nor influence their magnetic resonance imaging (MRI) contrast enhancement effects. Among the three particle samples, Fe3O4 nanoparticle coated with zwitterionic ligands, i.e., Fe3O4@DMSA, exhibited optimal renal clearance efficiency and reduced reticuloendothelial uptake. Therefore, this sample was further labeled with 99mTc through the DP moieties to achieve a renal-clearable MRI/single-photon emission computed tomography (SPECT) dual-modality imaging nanoprobe. The resulting nanoprobe showed satisfactory imaging capacities in a 4T1 xenograft tumor mouse model. Furthermore, the biocompatibility of Fe3O4@DMSA was evaluated both in vitro and in vivo through safety assessment experiments.

CONCLUSIONS

We believe that the current investigations offer a simple and effective strategy for constructing renal-clearable nanoparticles for precise disease diagnosis.

Toxicity of Large and Small Surface-Engineered Upconverting Nanoparticles for In Vitro and In Vivo Bioapplications

In this study, spherical or hexagonal NaYF4:Yb,Er nanoparticles (UCNPs) with sizes of 25 nm (S-UCNPs) and 120 nm (L-UCNPs) were synthesized by high-temperature coprecipitation and subsequently modified with three kinds of polymers. These included poly(ethylene glycol) (PEG) and poly(N,N-dimethylacrylamide-co-2-aminoethylacrylamide) [P(DMA-AEA)] terminated with an alendronate anchoring group, and poly(methyl vinyl ether-co-maleic acid) (PMVEMA). The internalization of nanoparticles by rat mesenchymal stem cells (rMSCs) and C6 cancer cells (rat glial tumor cell line) was visualized by electron microscopy and the cytotoxicity of the UCNPs and their leaches was measured by the real-time proliferation assay. The comet assay was used to determine the oxidative damage of the UCNPs. An in vivo study on mice determined the elimination route and potential accumulation of UCNPs in the body. The results showed that the L- and S-UCNPs were internalized into cells in the lumen of endosomes. The proliferation assay revealed that the L-UCNPs were less toxic than S-UCNPs. The viability of rMSCs incubated with particles decreased in the order S-UCNP@Ale-(PDMA-AEA) > S-UCNP@Ale-PEG > S-UCNPs > S-UCNP@PMVEMA. Similar results were obtained in C6 cells. The oxidative damage measured by the comet assay showed that neat L-UCNPs caused more oxidative damage to rMSCs than all coated UCNPs while no difference was observed in C6 cells. An in vivo study indicated that L-UCNPs were eliminated from the body via the hepatobiliary route; L-UCNP@Ale-PEG particles were almost eliminated from the liver 96 h after intravenous application. Pilot fluorescence imaging confirmed the limited in vivo detection capabilities of the nanoparticles.

Critical parameters to standardize the size and concentration determination of nanomaterials by nanoparticle tracking analysis

The size and concentration are critical for the diagnostic and therapeutic applications of nanomaterials but the accurate measurement remains challenging. Nanoparticle tracking analysis (NTA) is widely used for size and concentration determination. However, highly repeatable standard operating procedures (SOPs) are absent. We adopted the "search-evaluate-test" strategy to standardize the measurement by searching the critical parameters. The particles per frame are linearly proportional to the sample concentration and the measured results are more accurate and repeatable when the concentration is 108-109 particles/ml. The optimal detection threshold is around 5. The optimal camera level is such that it allows clear observation of particles without diffractive rings and overexposure. The optimal speed is ≤ 50 in AU and ∼ 10 μl/min in flow rate. We then evaluated the protocol using polydisperse polystyrene particles and we found that NTA could discriminate particles in bimodal mixtures with high size resolution but the performance on multimodal mixtures is not as good as that of resistive pulse sensing (RPS). We further analyzed the polystyrene particles, SiO2 particles, and biological samples by NTA following the SOPs. The size and concentration measured by NTA differentially varies to those determined by RPS and transmission electron microscopy.

Long-Term Accumulation, Biological Effects and Toxicity of BSA-Coated Gold Nanoparticles in the Mouse Liver, Spleen, and Kidneys

Introduction

Gold nanoparticles are promising candidates as vehicles for drug delivery systems and could be developed into effective anticancer treatments. However, concerns about their safety need to be identified, addressed, and satisfactorily answered. Although gold nanoparticles are considered biocompatible and nontoxic, most of the toxicology evidence originates from in vitro studies, which may not reflect the responses in complex living organisms.

Methods

We used an animal model to study the long-term effects of 20 nm spherical AuNPs coated with bovine serum albumin. Mice received a 1 mg/kg single intravenous dose of nanoparticles, and the biodistribution and accumulation, as well as the organ changes caused by the nanoparticles, were characterized in the liver, spleen, and kidneys during 120 days.

Results

The amount of nanoparticles in the organs remained high at 120 days compared with day 1, showing a 39% reduction in the liver, a 53% increase in the spleen, and a 150% increase in the kidneys. The biological effects of chronic nanoparticle exposure were associated with early inflammatory and fibrotic responses in the organs and were more pronounced in the kidneys, despite a negligible amount of nanoparticles found in renal tissues.

Conclusion

Our data suggest, that although AuNPs belong to the safest nanomaterial platforms nowadays, due to their slow tissue elimination leading to long-term accumulation in the biological systems, they may induce toxic responses in the vital organs, and so understanding of their long-term biological impact is important to consider their potential therapeutic applications.

Smart Design of ZnFe and ZnFe@Fe Nanoparticles for MRI-Tracked Magnetic Hyperthermia Therapy: Challenging Classical Theories of Nanoparticles Growth and Nanomagnetism

Iron Oxide Nanoparticles (IONPs) hold the potential to exert significant influence on fighting cancer through their theranostics capabilities as contrast agents (CAs) for magnetic resonance imaging (MRI) and as mediators for magnetic hyperthermia (MH). In addition, these capabilities can be improved by doping IONPs with other elements. In this work, the synthesis and characterization of single-core and alloy ZnFe novel magnetic nanoparticles (MNPs), with improved magnetic properties and more efficient magnetic-to-heat conversion, are reported. Remarkably, the results challenge classical nucleation and growth theories, which cannot fully predict the final size/shape of these nanoparticles and, consequently, their magnetic properties, implying the need for further studies to better understand the nanomagnetism phenomenon. On the other hand, leveraging the enhanced properties of these new NPs, successful tumor therapy by MH is achieved following their intravenous administration and tumor accumulation via the enhanced permeability and retention (EPR) effect. Notably, these results are obtained using a single low dose of MNPs and a single exposure to clinically suitable alternating magnetic fields (AMF). Therefore, as far as the authors are aware, for the first time, the successful application of intravenously administered MNPs for MRI-tracked MH tumor therapy in passively targeted tumor xenografts using clinically suitable conditions is demonstrated.

A stable, highly concentrated fluorous nanoemulsion formulation for in vivo cancer imaging via 19F-MRI

Magnetic resonance imaging (MRI) is a routine diagnostic modality in oncology that produces excellent imaging resolution and tumor contrast without the use of ionizing radiation. However, improved contrast agents are still needed to further increase detection sensitivity and avoid toxicity/allergic reactions associated with paramagnetic metal contrast agents, which may be seen in a small percentage of the human population. Fluorine-19 (19F)-MRI is at the forefront of the developing MRI methodologies due to near-zero background signal, high natural abundance of 100%, and unambiguous signal specificity. In this study, we have developed a colloidal nanoemulsion (NE) formulation that can encapsulate high volumes of the fluorous MRI tracer, perfluoro-[15-crown-5]-ether (PFCE) (35% v/v). These nanoparticles exhibit long-term (at least 100 days) stability and high PFCE loading capacity in formulation with our semifluorinated triblock copolymer, M2F8H18. With sizes of approximately 200 nm, these NEs enable in vivo delivery and passive targeting to tumors. Our diagnostic formulation, M2F8H18/PFCE NE, yielded in vivo 19F-MR images with a high signal-to-noise ratio up to 100 in a tumor-bearing mouse model at clinically relevant scan times. M2F8H18/PFCE NE circulated stably in the vasculature, accumulated in high concentration of an estimated 4-9 × 1017 19F spins/voxel at the tumor site, and cleared from most organs over the span of 2 weeks. Uptake by the mononuclear phagocyte system to the liver and spleen was also observed, most likely due to particle size. These promising results suggest that M2F8H18/PFCE NE is a favorable 19F-MR diagnostic tracer for further development in oncological studies and potential clinical translation.

Omega-3 polyunsaturated fatty acid derived lipid mediators: a comprehensive update on their application in anti-cancer drug discovery

INTRODUCTION

ω-3 Polyunsaturated fatty acids (PUFAs) have a range of health benefits, including anticancer activity, and are converted to lipid mediators that could be adapted into pharmacological strategies. However, the stability of these mediators must be improved, and they may require formulation to achieve optimal tissue concentrations.

AREAS COVERED

Herein, the author reviews the literature around chemical stabilization and formulation of ω-3 PUFA mediators and their application in anticancer drug discovery.

EXPERT OPINION

Aryl-urea bioisosteres of ω-3 PUFA epoxides that killed cancer cells targeted the mitochondrion by a novel dual mechanism: as protonophoric uncouplers and as inhibitors of electron transport complex III that activated ER-stress and disrupted mitochondrial integrity. In contrast, aryl-ureas that contain electron-donating substituents prevented cancer cell migration. Thus, aryl-ureas represent a novel class of agents with tunable anticancer properties. Stabilized analogues of other ω-3 PUFA-derived mediators could also be adapted into anticancer strategies. Indeed, a cocktail of agents that simultaneously promote cell killing, inhibit metastasis and angiogenesis, and that attenuate the pro-inflammatory microenvironment is a novel future anticancer strategy. Such regimen may enhance anticancer drug efficacy, minimize the development of anticancer drug resistance and enhance outcomes.

Nanomedomics

Nanomaterials have attractive physicochemical properties. A variety of nanomaterials such as inorganic, lipid, polymers, and protein nanoparticles have been widely developed for nanomedicine via chemical conjugation or physical encapsulation of bioactive molecules. Superior to traditional drugs, nanomedicines offer high biocompatibility, good water solubility, long blood circulation times, and tumor-targeting properties. Capitalizing on this, several nanoformulations have already been clinically approved and many others are currently being studied in clinical trials. Despite their undoubtful success, the molecular mechanism of action of the vast majority of nanomedicines remains poorly understood. To tackle this limitation, herein, this review critically discusses the strategy of applying multiomics analysis to study the mechanism of action of nanomedicines, named nanomedomics, including advantages, applications, and future directions. A comprehensive understanding of the molecular mechanism could provide valuable insight and therefore foster the development and clinical translation of nanomedicines.