Clearance properties of nano-sized particles and molecules as imaging agents: considerations and caveats

Drug delivery in leptomeningeal disease: Navigating barriers and beyond

Leptomeningeal disease (LMD) refers to the infiltration of cancer cells into the leptomeningeal compartment. Leptomeninges are the two membranous layers, called the arachnoid membrane and pia mater. The diffuse nature of LMD poses a challenge to its effective diagnosis and successful management. Furthermore, the predominant phenotype; solid masses or freely floating cells, has altering implications on the effectiveness of drug delivery systems. The standard of care is the intrathecal delivery of chemotherapy drugs but it is associated with increased instances of treatment-related complications, low patient compliance, and suboptimal drug distribution. An alternative involves administering the drugs systemically, after which they must traverse fluid barriers to arrive at their destination within the leptomeningeal space. However, this route is known to cause off-target effects as well as produce subtherapeutic drug concentrations at the target site within the central nervous system. The development of new drug delivery systems such as liposomal cytarabine has improved drug delivery in leptomeningeal metastatic disease, but much still needs to be done to effectively target this challenging condition. In this review, we discuss about the anatomy of leptomeninges relevant for drug penetration, the conventional and advanced drug delivery methods for LMD. We also discuss the future directions being set by different clinical trials.

Bornite (Cu5FeS4) nanocrystals as an ultrasmall biocompatible NIR-II contrast agent for photoacoustic imaging

In this study, we demonstrate the potential of the bornite crystal structure (Cu5FeS4) of copper iron sulfide as a second near infrared (NIR-II) photoacoustic (PA) contrast agent. Bornite exhibits comparable dose-dependent biocompatibility to copper sulfide nanoparticles in a cell viability study with HepG2 cells, while exhibiting a 10-fold increase in PA amplitude. In comparison to other benchmark contrast agents at similar mass concentrations, bornite demonstrated a 10× increase in PA amplitude compared to indocyanine green (ICG) and a 5× increase compared to gold nanorods (AuNRs). PA signal was detectable with a light pathlength greater than 5 cm in porcine tissue phantoms at bornite concentrations where in vitro cell viability was maintained. In vivo imaging of mice vasculature resulted in a 2× increase in PA amplitude compared to AuNRs. In summary, bornite is a promising NIR-II contrast agent for deep tissue PA imaging.

Recent advances of copper-based metal phenolic networks in biomedical applications

Metal-phenolic Networks (MPNs) are a novel class of nanomaterial developed gradually in recent years which are self-assembled by metal ions and polyphenolic ligands. Due to their environmental protection, good adhesion, and biocompatibility with green phenolic ligands, MPNs can be used as a new type of nanomaterial. They show excellent properties such as anti-inflammatory, antioxidant, antibacterial, and anticancer, and have been widely studied in the biomedical field. As one of the most common subclasses of the MPNs family, copper-based MPNs have been widely studied for drug delivery, Photodynamic Therapy (PDT), Chemo dynamic Therapy (CDT), antibacterial and anti-inflammatory, bone tissue regeneration, skin regeneration wound repair, and metal ion imaging. In this paper, the preparation strategies of different types of copper-based MPNs are reviewed. Then, the application status of copper-based MPNs in the biomedical field under different polyphenol ligands is introduced in detail. Finally, the existing problems and challenges of copper-based MPNs are discussed, as well as their future application prospects in the biomedical field.

Microfluidic technologies for lipid vesicle generation

Encapsulating biological and non-biological materials in lipid vesicles presents significant potential in both industrial and academic settings. When smaller than 100 nm, lipid vesicles and lipid nanoparticles are ideal vehicles for drug delivery, facilitating the delivery of payloads, improving pharmacokinetics, and reducing the off-target effects of therapeutics. When larger than 1 μm, vesicles are useful as model membranes for biophysical studies, as synthetic cell chassis, as bio-inspired supramolecular devices, and as the basis of protocells to explore the origin of life. As applications of lipid vesicles gain prominence in the fields of nanomedicine, biotechnology, and synthetic biology, there is a demand for advanced technologies for their controlled construction, with microfluidic methods at the forefront of these developments. Compared to conventional bulk methods, emerging microfluidic methods offer advantages such as precise size control, increased production throughput, high encapsulation efficiency, user-defined membrane properties (i.e., lipid composition, vesicular architecture, compartmentalisation, membrane asymmetry, etc.), and potential integration with lab-on-chip manipulation and analysis modules. We provide a review of microfluidic lipid vesicle generation technologies, focusing on recent advances and state-of-the-art techniques. Principal technologies are described, and key research milestones are highlighted. The advantages and limitations of each approach are evaluated, and challenges and opportunities for microfluidic engineering of lipid vesicles to underpin a new generation of therapeutics, vaccines, sensors, and bio-inspired technologies are presented.

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.

Hybrid Nanoparticles of Extracellular Vesicles and Gemcitabine Prodrug-Loaded Liposomes with Enhanced Targeting Ability for Effective PDAC Treatment

Liposomes are applied to various anticancer treatments as representative drug delivery carriers. However, liposomes do not have their own targeting properties; therefore, there are limitations in drug delivery to specific tissues or cells. High targetability in drug delivery is an important factor in improving bioavailability and drug efficacy and reducing side effects; recent research has been actively investigated to modify the surface of liposomes to give them specific functions. In this study, we studied a drug delivery system for anticancer treatment that enhances targeting ability through fusion with exosomes on the surface of liposomes. We designed exosome-liposome hybrid nanoparticles loaded with a gemcitabine prodrug as a treatment for pancreatic ductal adenocarcinoma (PDAC). Membrane fusion with exosomes shows excellent targeting ability to pancreatic cancer cells due to intrinsic targeting ability and expansion of the macropinocytosis pathway.

Sodium lanthanide tungstate-based nanoparticles as bimodal contrast agents for in vivo high-field MRI and CT imaging

Research on high-field magnetic resonance imaging (HF-MRI) has been increased in recent years, aiming to improve diagnosis accuracy by increasing the signal-to-noise ratio and hence image quality. Conventional contrast agents (CAs) have important limitations for HF-MRI, with the consequent need for the development of new CAs. Among them, the most promising alternatives are those based on Dy3+ or Ho3+ compounds. Notably, the high atomic number of lanthanide cations would bestow a high capability for X-ray attenuation to such Dy or Ho-based compounds, which would also allow them to be employed as CAs for X-ray computed tomography (CT). In this work, we have prepared uniform NaDy(WO4)2 and NaHo(WO4)2 nanoparticles (NPs), which were dispersible under conditions that mimic the physiological media and were nontoxic for cells, meeting the main requirements for their use in vivo. Both NPs exhibited satisfactory magnetic relaxivities at 9.4 T, thus making them a promising alternative to clinical CAs for HF-MRI. Furthermore, after their intravenous administration in tumor-bearing mice, both NPs exhibited significant accumulation inside the tumor at 24 h, attributable to passive targeting by the enhanced permeability and retention (EPR) effect. Therefore, our NPs are suitable for the detection of tumors through HF-MRI. Finally, NaDy(WO4)2 NPs showed a superior X-ray attenuation capability than iohexol (commercial CT CA), which, along with their high r2 value, makes them suitable as the dual-probe for both HF-MRI and CT imaging, as demonstrated by in vivo experiments conducted using healthy mice.

Nanotechnology-Based Drug Delivery Systems for Treating Acute Kidney Injury

Acute kidney injury (AKI) is a disease that is characterized by a rapid decline in renal function and has a relatively high incidence in hospitalized patients. Sepsis, renal hypoperfusion, and nephrotoxic drug exposure are the main causes of AKI. The major therapy measures currently include supportive treatment, symptomatic treatment, and kidney transplantation. These methods are supportive treatments, and their results are not satisfactory. Fortunately, many new treatments that markedly improve the AKI therapy efficiency are emerging. These include antioxidant therapy, ferroptosis therapy, anti-inflammatory therapy, autophagy therapy, and antiapoptotic therapy. In addition, the development of nanotechnology has further promoted therapeutic effects on AKI. In this review, we highlight recent advances in the development of nanocarriers for AKI drug delivery. Emphasis has been placed on the latest developments in nanocarrier modification and design. We also summarize the applications of different nanocarriers in AKI treatment. Finally, the advantages and challenges of nanocarrier applications in AKI are summarized, and several nanomedicines that have been approved for clinical trials to treat diverse kidney diseases are listed.

Brain Nucleic Acid Delivery and Genome Editing via Focused Ultrasound-Mediated Blood-Brain Barrier Opening and Long-Circulating Nanoparticles

We introduce a two-pronged strategy comprising focused ultrasound (FUS)-mediated blood-brain barrier (BBB) opening and long-circulating biodegradable nanoparticles (NPs) for systemic delivery of nucleic acids to the brain. Biodegradable poly(β-amino ester) polymer-based NPs were engineered to stably package various types of nucleic acid payloads and enable prolonged systemic circulation while retaining excellent serum stability. FUS was applied to a predetermined coordinate within the brain to transiently open the BBB, thereby allowing the systemically administered long-circulating NPs to traverse the BBB and accumulate in the FUS-treated brain region, where plasmid DNA or mRNA payloads produced reporter proteins in astrocytes and neurons. In contrast, poorly circulating and/or serum-unstable NPs, including the lipid NP analogous to a platform used in clinic, were unable to provide efficient nucleic acid delivery to the brain regardless of the BBB-opening FUS. The marriage of FUS-mediated BBB opening and the long-circulating NPs engineered to copackage mRNA encoding CRISPR-associated protein 9 and single-guide RNA resulted in genome editing in astrocytes and neurons precisely in the FUS-treated brain region. The combined delivery strategy provides a versatile means to achieve efficient and site-specific therapeutic nucleic acid delivery to and genome editing in the brain via a systemic route.

Catalytic Nanoparticles in Biomedical Applications: Exploiting Advanced Nanozymes for Therapeutics and Diagnostics

Catalytic nanoparticles (CNPs) as heterogeneous catalyst reveals superior activity due to their physio-chemical features, such as high surface-to-volume ratio and unique optical, electric, and magnetic properties. The CNPs, based on their physio-chemical nature, can either increase the reactive oxygen species (ROS) level for tumor and antibacterial therapy or eliminate the ROS for cytoprotection, anti-inflammation, and anti-aging. In addition, the catalytic activity of nanozymes can specifically trigger a specific reaction accompanied by the optical feature change, presenting the feasibility of biosensor and bioimaging applications. Undoubtedly, CNPs play a pivotal role in pushing the evolution of technologies in medical and clinical fields, and advanced strategies and nanomaterials rely on the input of chemical experts to develop. Herein, a systematic and comprehensive review of the challenges and recent development of CNPs for biomedical applications is presented from the viewpoint of advanced nanomaterial with unique catalytic activity and additional functions. Furthermore, the biosafety issue of applying biodegradable and non-biodegradable nanozymes and future perspectives are critically discussed to guide a promising direction in developing span-new nanozymes and more intelligent strategies for overcoming the current clinical limitations.

Light-responsive functional nanomaterials as pioneering therapeutics: a paradigm shift to combat age-related disorders

Aging, marked by dysregulated cellular systems, gives rise to a spectrum of age-related disorders, including neurodegeneration, atherosclerosis, immunosenescence, and musculoskeletal issues. These conditions contribute significantly to the global disease burden, posing challenges to health span and economic resources. Current therapeutic approaches, although diverse in mechanism, often fall short in targeting the underlying cellular pathologies. They fail to address the issues compounded by altered pharmacokinetics in the elderly. Nanotechnology emerges as a transformative solution, offering tissue-specific targeted therapies through nanoparticles. Functional nanomaterials (FNMs) respond to internal or external stimuli, with light-responsive nanomaterials gaining prominence. Harnessing the benefits of deep tissue penetration and ease of manipulation particularly in the near-infrared spectrum, light-responsive FNMs present innovative strategies for age-related comorbidities. This review comprehensively summarizes the potential of light-responsive FNM-based approaches for targeting cellular environments in age-related disorders, and also emphasizes the advantages over traditional treatment modalities. Specifically, it focuses on the development of various classes of light-responsive functional nanomaterials including plasmonic nanomaterials, nanomaterials as carriers, upconversion nanomaterials, 2D nanomaterials, transition metal oxide and dichalcogenide nanomaterials and carbon-based nanomaterials against age related diseases. We foresee that such advanced developments in the field of nanotechnology could provide a new hope for clinical diagnosis and treatment of age-related disorders.

Nanomaterials in Immunology: Bridging Innovative Approaches in Immune Modulation, Diagnostics, and Therapy

The intersection of immunology and nanotechnology has provided significant advancements in biomedical research and clinical applications over the years. Immunology aims to understand the immune system's defense mechanisms against pathogens. Nanotechnology has demonstrated its potential to manipulate immune responses, as nanomaterials' properties can be modified for the desired application. Research has shown that nanomaterials can be applied in diagnostics, therapy, and vaccine development. In diagnostics, nanomaterials can be used for biosensor development, accurately detecting biomarkers even at very low concentrations. Therapeutically, nanomaterials can act as efficient carriers for delivering drugs, antigens, or genetic material directly to targeted cells or tissues. This targeted delivery improves therapeutic efficacy and reduces the adverse effects on healthy cells and tissues. In vaccine development, nanoparticles can improve vaccine durability and extend immune responses by effectively delivering adjuvants and antigens to immune cells. Despite these advancements, challenges regarding the safety, biocompatibility, and scalability of nanomaterials for clinical applications are still present. This review will cover the fundamental interactions between nanomaterials and the immune system, their potential applications in immunology, and their safety and biocompatibility concerns.

Influence of Physicochemical Properties of Iron Oxide Nanoparticles on Their Antibacterial Activity

The increasing occurrence of infectious diseases caused by antimicrobial resistance organisms urged the necessity to develop more potent, selective, and safe antimicrobial agents. The unique magnetic and tunable properties of iron oxide nanoparticles (IONPs) make them a promising candidate for different theragnostic applications, including antimicrobial agents. Though IONPs act as a nonspecific antimicrobial agent, their antimicrobial activities are directly or indirectly linked with their synthesis methods, synthesizing precursors, size, shapes, concentration, and surface modifications. Alteration of these parameters could accelerate or decelerate the production of reactive oxygen species (ROS). An increase in ROS role production disrupts bacterial cell walls, cell membranes, alters major biomolecules (e.g., lipids, proteins, nucleic acids), and affects metabolic processes (e.g., Krebs cycle, fatty acid synthesis, ATP synthesis, glycolysis, and mitophagy). In this review, we will investigate the antibacterial activity of bare and surface-modified IONPs and the influence of physiochemical parameters on their antibacterial activity. Additionally, we will report the potential mechanism of IONPs' action in driving this antimicrobial activity.

A Facile Approach to Producing Liposomal J-Aggregates of Indocyanine Green with Diagnostic and Therapeutic Potential

Liposomal J-Aggregates of Indocyanine Green (L-JA) can serve as a biocompatible and biodegradable nanoparticle for photoacoustic imaging and photothermal therapy. When compared to monomeric IcG, L-JA are characterized by longer circulation, improved photostability, elevated absorption at longer wavelengths, and increased photoacoustic signal generation. However, the documented methods for production of L-JA vary widely. We developed an approach to efficiently form IcG J-aggregates (IcG-JA) directly in liposomes at elevated temperatures. Aggregating within fully formed liposomes ensures particle uniformity and allows for control of J-aggregate size. L-JA have unique properties compared to IcG. L-JA provide significant contrast enhancement in photoacoustic images for up to 24 hours after injection, while IcG and unencapsulated IcG-JA are cleared within an hour. L-JA allow for more accurate photoacoustic-based sO2 estimation and particle tracking compared to IcG. Furthermore, photothermal heating of L-JA with an 852nm laser is demonstrated to be more effective at lower laser powers than conventional 808nm lasers for the first time. The presented technique offers an avenue for formulating a multi-faceted contrast agent for photoacoustic imaging and photothermal therapy that offers significant advantages over other conventional agents.

Polymeric pH-Responsive Metal-Supramolecular Nanoparticles for Synergistic Chemo-Photothermal Therapy

Stimuli-responsive drug delivery carriers, particularly those exhibiting pH sensitivity, have attracted significant scholarly interest due to their promising potential in anticancer therapeutic applications. This phenomenon can primarily be ascribed to the inherently acidic nature of tumor microenvironments. However, pH-responsive carriers frequently require the incorporation of functional groups or materials sensitive to pH changes. Given the pH-sensitive characteristics of metal coordination with natural small-molecule drugs, organometallic supramolecules present a facile and effective strategy for integrating pH-responsive behavior into these systems. Meanwhile, utilizing the natural compound luteolin in conjunction with iron ions (Fe3+) through the advanced engineering technique of flash nanoprecipitation (FNP) results in the synthesis of stable, highly loaded nanoparticles (NPs) exhibiting a supramolecular photothermal effect. Our experimental findings substantiate that the photothermal effect persists over time, even after the pH-responsive release phase has ended. Consequently, these polymeric pH-responsive metallic supramolecular nanoparticles integrate chemotherapy and photothermal therapy, creating a synergistic approach to cancer treatment. This bifunctional platform, which exhibits both pH-responsive and photothermal properties, presents a highly promising avenue for biomedical applications, particularly in the area of tumor therapies. Its dual function offers a potentially efficacious approach to tumor treatment.

Advances in active targeting of ligand-directed polymeric nanomicelles via exploiting overexpressed cellular receptors for precise nanomedicine

Many of the utilized drugs which already exist in the pharmaceutical sector are hydrophobic in nature. These drugs are characterized by being poorly absorbed and difficult to formulate in aqueous environments with low bioavailability, which could result in consuming high and frequent doses in order to fulfil the required therapeutic effect. As a result, there is a decisive demand to find modern alternatives to overcome all these drawbacks. Self-assembling polymeric nanomicelles (PMs) with their unique structure appear to be a fascinating choice as a pharmaceutical carrier system for improving the solubility & bioavailability of many drugs. PMs as drug carriers have many advantages including suitable size, high stability, prolonged circulation time, elevated cargo capacity and controlled therapeutic release. Otherwise, the pathological features of some diseased cells, like cancer, allow PMs with particle size <200 nm to be passively uptaken via enhanced permeability and retention phenomenon (EPR). However, the passive targeting approach was proven to be insufficient in many cases. Consequently, the therapeutic efficiency of these PMs can be further reinforced by enhancing their cellular internalization via incorporating targeting ligands. These targeting ligands can enhance the assemblage of loaded cargos in the intended tissues via receptor-mediated endocytosis through exploiting receptors robustly expressed on the exterior of the intended tissue while minimizing their toxic effects. In this review, the up-to-date approaches of harnessing active targeting ligands to exploit certain overexpressed receptors will be summarized concerning the functionalization of the exterior of PMs for ameliorating their targeting potential in the scope of nanomedicine.

Magnetic-guided nanocarriers for ionizing/non-ionizing radiation synergistic treatment against triple-negative breast cancer

BACKGROUND

Triple-negative breast cancer (TNBC) is a subtype of breast cancer with the worst prognosis. Radiotherapy (RT) is one of the core modalities for the disease; however, the ionizing radiation of RT has severe side effects. The consistent development direction of RT is to achieve better therapeutic effect with lower radiation dose. Studies have demonstrated that synergistic effects can be achieved by combining RT with non-ionizing radiation therapies such as light and magnetic therapy, thereby achieving the goal of dose reduction and efficacy enhancement.

METHODS

In this study, we applied FeCo NPs with magneto thermal function and phototherapeutic agent IR-780 to construct an ionizing and non-ionizing radiation synergistic nanoparticle (INS NPs). INS NPs are first subjected to morphology, size, colloidal stability, loading capacity, and photothermal conversion tests. Subsequently, the cell inhibitory and cellular internalization were evaluated using cell lines in vitro. Following comprehensive assessment of the NPs' in vivo biocompatibility, tumor-bearing mouse model was established to evaluate their distribution, targeted delivery, and anti-tumor effects in vivo.

RESULTS

INS NPs have a saturation magnetization exceeding 72 emu/g, a hydrodynamic particle size of approximately 40 nm, a negatively charged surface, and good colloidal stability and encapsulation properties. INS NPs maintain the spectral characteristics of IR-780 at 808 nm. Under laser irradiation, the maximum temperature was 92 °C, INS NPs also achieved the effective heat temperature in vivo. Both in vivo and in vitro tests have proven that INS NPs have good biocompatibility. INS NPs remained effective for more than a week after one injection in vivo, and can also be guided and accumulated in tumors through permanent magnets. Later, the results exhibited that under low-dose RT and laser irradiation, the combined intervention group showed significant synergetic effects, and the ROS production rate was much higher than that of the RT and phototherapy-treated groups. In the mice model, 60% of the tumors were completely eradicated.

CONCLUSIONS

INS NPs effectively overcome many shortcomings of RT for TNBC and provide experimental basis for the development of novel clinical treatment methods for TNBC.

Ultrasound-Based Micro-/Nanosystems for Biomedical Applications

Due to the intrinsic non-invasive nature, cost-effectiveness, high safety, and real-time capabilities, besides diagnostic imaging, ultrasound as a typical mechanical wave has been extensively developed as a physical tool for versatile biomedical applications. Especially, the prosperity of nanotechnology and nanomedicine invigorates the landscape of ultrasound-based medicine. The unprecedented surge in research enthusiasm and dedicated efforts have led to a mass of multifunctional micro-/nanosystems being applied in ultrasound biomedicine, facilitating precise diagnosis, effective treatment, and personalized theranostics. The effective deployment of versatile ultrasound-based micro-/nanosystems in biomedical applications is rooted in a profound understanding of the relationship among composition, structure, property, bioactivity, application, and performance. In this comprehensive review, we elaborate on the general principles regarding the design, synthesis, functionalization, and optimization of ultrasound-based micro-/nanosystems for abundant biomedical applications. In particular, recent advancements in ultrasound-based micro-/nanosystems for diagnostic imaging are meticulously summarized. Furthermore, we systematically elucidate state-of-the-art studies concerning recent progress in ultrasound-based micro-/nanosystems for therapeutic applications targeting various pathological abnormalities including cancer, bacterial infection, brain diseases, cardiovascular diseases, and metabolic diseases. Finally, we conclude and provide an outlook on this research field with an in-depth discussion of the challenges faced and future developments for further extensive clinical translation and application.

Lung-Specific mRNA Delivery Enabled by Sulfonium Lipid Nanoparticles

Among various mRNA carrier systems, lipid nanoparticles (LNPs) stand out as the most clinically advanced. While current clinical trials of mRNA/LNP therapeutics mainly address liver diseases, the potential of mRNA therapy extends far beyond─yet to be unraveled. To fully unlock the promises of mRNA therapy, there is an urgent need to develop safe and effective LNP systems that can target extrahepatic organs. Here, we report on the development of sulfonium lipid nanoparticles (sLNPs) for systemic mRNA delivery to the lungs. sLNP effectively and specifically delivered mRNA to the lungs following intravenous administration in mice. No evidence of lung and systemic inflammation or toxicity in major organs was induced by sLNP. Our findings demonstrated that the newly developed lung-specific sLNP platform is both safe and efficacious. It holds great promise for advancing the development of new mRNA-based therapies for the treatment of lung-associated diseases and conditions.

Chronic exposure to TiO2 micro- and nano particles: A biochemical and histopathological experimental study

The aim of this work was to analyze the effects of long-term exposure to titanium dioxide (TiO2) micro- (MPs) and nanoparticles (NPs) (six and 12 months) on the biochemical and histopathological response of target organs using a murine model. Male Wistar rats were intraperitoneally injected with a suspension of TiO2 NPs (5 nm; TiO2-NP5 group) or MPs (45 μm; TiO2-NP5 group); the control group was injected with saline solution. Six and 12 months post-injection, titanium (Ti) concentration in plasma and target organs was determined spectrometrically (ICP-MS). Blood smears and organ tissue samples were evaluated by light microscopy. Liver and kidney function was evaluated using serum biochemical parameters. Oxidative metabolism was assessed 6 months post-injection (determination of superoxide anion by nitroblue tetrazolium (NBT) test, superoxide dismutase (SOD) and catalase (CAT), lipid peroxidation, and paraoxonase 1). Titanium (Ti) concentration in target organs and plasma was significantly higher in the TiO2-exposed groups than in the control group. Histological evaluation showed the presence of titanium-based particles in the target organs, which displayed no structural alterations, and in blood monocytes. Oxidative metabolism analysis showed that TiO2 NPs were more reactive over time than MPs (p < .05) and mobilization of antioxidant enzymes and membrane damage varied among the studied organs. Clearance of TiO2 micro and nanoparticles differed among the target organs, and lung clearance was more rapid than clearance from the lungs and kidneys (p < .05). Conversely, Ti concentration in plasma increased with time (p < .05). In conclusion, neither serum biochemical parameters nor oxidative metabolism markers appear to be useful as biomarkers of tissue damage in response to TiO2 micro- and nanoparticle deposits at chronic time points.

Parameter grouping and co-estimation in physiologically based kinetic models using genetic algorithms

Physiologically based kinetic (PBK) models are widely used in pharmacology and toxicology for predicting the internal disposition of substances upon exposure, voluntarily or not. Due to their complexity, a large number of model parameters need to be estimated, either through in silico tools, in vitro experiments, or by fitting the model to in vivo data. In the latter case, fitting complex structural models on in vivo data can result in overparameterization and produce unrealistic parameter estimates. To address these issues, we propose a novel parameter grouping approach, which reduces the parametric space by co-estimating groups of parameters across compartments. Grouping of parameters is performed using genetic algorithms and is fully automated, based on a novel goodness-of-fit metric. To illustrate the practical application of the proposed methodology, two case studies were conducted. The first case study demonstrates the development of a new PBK model, while the second focuses on model refinement. In the first case study, a PBK model was developed to elucidate the biodistribution of titanium dioxide (TiO2) nanoparticles in rats following intravenous injection. A variety of parameter estimation schemes were employed. Comparative analysis based on goodness-of-fit metrics demonstrated that the proposed methodology yields models that outperform standard estimation approaches, while utilizing a reduced number of parameters. In the second case study, an existing PBK model for perfluorooctanoic acid (PFOA) in rats was extended to incorporate additional tissues, providing a more comprehensive portrayal of PFOA biodistribution. Both models were validated through independent in vivo studies to ensure their reliability.

PEGylated Micro/Nanoparticles Based on Biodegradable Poly(Ester Amides): Preparation and Study of the Core-Shell Structure by Synchrotron Radiation-Based FTIR Microspectroscopy and Electron Microscopy

Surface modification of drug-loaded particles with polyethylene glycol (PEG) chains is a powerful tool that promotes better transport of therapeutic agents, provides stability, and avoids their detection by the immune system. In this study, we used a new approach to synthesize a biodegradable poly(ester amide) (PEA) and PEGylating surfactant. These were employed to fabricate micro/nanoparticles with a core-shell structure. Nanoparticle (NP)-protein interactions and self-assembling were subsequently studied by synchrotron radiation-based FTIR microspectroscopy (SR-FTIRM) and transmission electron microscopy (TEM) techniques. The core-shell structure was identified using IR absorption bands of characteristic chemical groups. Specifically, the stretching absorption band of the secondary amino group (3300 cm-1) allowed us to identify the poly(ester amide) core, while the band at 1105 cm-1 (C-O-C vibration) was useful to demonstrate the shell structure based on PEG chains. By integration of absorption bands, a 2D intensity map of the particle was built to show a core-shell structure, which was further supported by TEM images.

Immunofilaments Are Well Tolerated after Local or Systemic Administration in Mice

The invention of nanosized biomaterials has paved the way for novel therapeutics that can manipulate cells on a nanoscale. Nanosized immunofilaments (IFs) are synthetic filamentous polymers consisting out of polyisocyanopeptides, which have been recently established as a powerful platform to activate specific immune cells in vivo such that they raise an antitumor immune response. However, toxicological effects or immunogenicity toward the IFs have not yet been investigated. In this study, we evaluated potential toxic or immunogenic effects in C57BL/6 mice upon intravenous or subcutaneous injection of nonfunctionalized IFs or immunostimulatory IFs over 30 days. We here present a detailed analysis of the gross pathology, hematological parameters, blood biochemistry, histology, and antibody-response against the IF backbone. Our results demonstrate that IFs do not induce severe acute or chronic toxicity in mice. After 30 days, we only found elevated IgG-titers in intravenously injected but not subcutaneously injected mice. In summary, we demonstrate that IFs can be administered into a living organism without adverse side effects, thereby establishing the safety of IFs as a therapeutic intervention.

Multimodal Imaging-Guided Stem Cell Ocular Treatment

Stem cell therapies are gaining traction as promising treatments for a variety of degenerative conditions. Both clinical and preclinical studies of regenerative medicine are hampered by the lack of technologies that can evaluate the migration and behavior of stem cells post-transplantation. This study proposes an innovative method to longitudinally image in vivo human-induced pluripotent stem cells differentiated to retinal pigment epithelium (hiPSC-RPE) cells by multimodal photoacoustic microscopy, optical coherence tomography, and fluorescence imaging powered by ultraminiature chain-like gold nanoparticle cluster (GNC) nanosensors. The GNC exhibits an optical absorption peak in the near-infrared regime, and the 7-8 nm size in diameter after disassembly enables renal excretion and improved safety as well as biocompatibility. In a clinically relevant rabbit model, GNC-labeled hiPSC-RPE cells migrated to RPE degeneration areas and regenerated damaged tissues. The hiPSC-RPE cells' distribution and migration were noninvasively, longitudinally monitored for 6 months with exceptional sensitivity and spatial resolution. This advanced platform for cellular imaging has the potential to enhance regenerative cell-based therapies.

A novel nanoformulation of parthenolide coated with polydopamine shows selective cytotoxicity and induces apoptosis in gastric cancer cells

An anticancer agent derived from a natural product, parthenolide (PN), was studied to formulate PN into poly(lactic-co-glycolic acid) (PLGA). Polydopamine (PDA) was employed to modify the surface of PN-PLGA. Following characterization, the PN-PLGA-PDA was evaluated for its in vitro release, cytotoxicity, and ability to induce apoptosis using flow cytometry and real-time quantitative PCR. According to the present study, PN-PLGA-PDA had a size of 195.5 nm which is acceptable for efficient enhanced permeation and retention (EPR) performance. The SEM results confirmed the size and spherical shape of the nanoparticles. The percentage of encapsulation efficiency was 96.9%. The zeta potential of PN-PLGA-PDA was - 31.8 mV which was suitable for its stability. FTIR spectra of the PN-PLGA-PDA indicated the chemical stability of the PN due to intermolecular hydrogen bonds between polymer and drug. The release of PN from PN-PLGA-PDA in PBS (pH 7.4) was only 20% during the first 48 h and less than 40% during 144 h. PN-PLGA-PDA exhibited anticancer properties in a dose-dependent manner that was more cytotoxic against cancer cells than normal cells. Moreover, real-time qPCR results indicated that the formulation activated apoptosis genes to exert its cytotoxic effect and activate the NF-kB pathway. Based on our findings, PN-PLGA-PDA could serve as a potential treatment for cancer.

Spleen-targeted delivery systems and strategies for spleen-related diseases

The spleen, body's largest secondary lymphoid organ, is also a vital hematopoietic and immunological organ. It is regarded as one of the most significant organs in humans. As more researchers recognize the functions of the spleen, clinical methods for treating splenic diseases and spleen-targeted drug delivery systems to improve the efficacy of spleen-related therapies have gradually developed. Many modification strategies (size, charge, ligand, protein corona) and hitchhiking strategies (erythrocytes, neutrophils) of nanoparticles (NPs) have shown a significant increase in spleen targeting efficiency. However, most of the targeted drug therapy strategies for the spleen are to enhance or inhibit the immune function of the spleen to achieve therapeutic effects, and there are few studies on spleen-related diseases. In this review, we not only provide a detailed summary of the design rules for spleen-targeted drug delivery systems in recent years, but also introduce common spleen diseases (splenic tumors, splenic injuries, and splenomegaly) with the hopes of generating more ideas for future spleen research.

Rational Design of NIR-II Emitting Conjugated Polymer Derived Nanoparticles for Image-Guided Cancer Interventions

Due to the reduced absorption, light scattering, and tissue autofluorescence in the NIR-II (1000-1700 nm) region, significant efforts are underway to explore diverse material platforms for in vivo fluorescence imaging, particularly for cancer diagnostics and image-guided interventions. Of the reported imaging agents, nanoparticles derived from conjugated polymers (CPNs) offer unique advantages to alternative materials including biocompatibility, remarkable absorption cross-sections, exceptional photostability, and tunable emission behavior independent of cell labeling functionalities. Herein, the current state of NIR-II emitting CPNs are summarized and structure-function-property relationships are highlighted that can be used to elevate the performance of next-generation CPNs. Methods for particle processing and incorporating cancer targeting modalities are discussed, as well as detailed characterization methods to improve interlaboratory comparisons of novel materials. Contemporary methods to specifically apply CPNs for cancer diagnostics and therapies are then highlighted. This review not only summarizes the current state of the field, but offers future directions and provides clarity to the advantages of CPNs over other classes of imaging agents.

Hopping the Hurdle: Strategies to Enhance the Molecular Delivery to the Brain through the Blood-Brain Barrier

Modern medicine has allowed for many advances in neurological and neurodegenerative disease (ND). However, the number of patients suffering from brain diseases is ever increasing and the treatment of brain diseases remains an issue, as drug efficacy is dramatically reduced due to the existence of the unique vascular structure, namely the blood-brain barrier (BBB). Several approaches to enhance drug delivery to the brain have been investigated but many have proven to be unsuccessful due to limited transport or damage induced in the BBB. Alternative approaches to enhance molecular delivery to the brain have been revealed in recent studies through the existence of molecular delivery pathways that regulate the passage of peripheral molecules. In this review, we present recent advancements of the basic research for these delivery pathways as well as examples of promising ventures to overcome the molecular hurdles that will enhance therapeutic interventions in the brain and potentially save the lives of millions of patients.

Nanozyme as a rising star for metabolic disease management

Nanozyme, characterized by outstanding and inherent enzyme-mimicking properties, have emerged as highly promising alternatives to natural enzymes owning to their exceptional attributes such as regulation of oxidative stress, convenient storage, adjustable catalytic activities, remarkable stability, and effortless scalability for large-scale production. Given the potent regulatory function of nanozymes on oxidative stress and coupled with the fact that reactive oxygen species (ROS) play a vital role in the occurrence and exacerbation of metabolic diseases, nanozyme offer a unique perspective for therapy through multifunctional activities, achieving essential results in the treatment of metabolic diseases by directly scavenging excess ROS or regulating pathologically related molecules. The rational design strategies, nanozyme-enabled therapeutic mechanisms at the cellular level, and the therapies of nanozyme for several typical metabolic diseases and underlying mechanisms are discussed, mainly including obesity, diabetes, cardiovascular disease, diabetic wound healing, and others. Finally, the pharmacokinetics, safety analysis, challenges, and outlooks for the application of nanozyme are also presented. This review will provide some instructive perspectives on nanozyme and promote the development of enzyme-mimicking strategies in metabolic disease therapy.

Therapeutic induction of antigen-specific immune tolerance

The development of therapeutic approaches for the induction of robust, long-lasting and antigen-specific immune tolerance remains an important unmet clinical need for the management of autoimmunity, allergy, organ transplantation and gene therapy. Recent breakthroughs in our understanding of immune tolerance mechanisms have opened new research avenues and therapeutic opportunities in this area. Here, we review mechanisms of immune tolerance and novel methods for its therapeutic induction.

Implications of environmental nanoparticles on neurodegeneration

The ubiquity of nanoparticles, sourced from both natural environments and human activities, presents critical challenges for public health. While offering significant potential for innovative biomedical applications-especially in enhancing drug transport across the blood-brain barrier-these particles also introduce possible hazards due to inadvertent exposure. This concise review explores the paradoxical nature of nanoparticles, emphasizing their promising applications in healthcare juxtaposed with their potential neurotoxic consequences. Through a detailed examination, we delineate the pathways through which nanoparticles can reach the brain and the subsequent health implications. There is growing evidence of a disturbing association between nanoparticle exposure and the onset of neurodegenerative conditions, highlighting the imperative for comprehensive research and strategic interventions. Gaining a deep understanding of these mechanisms and enacting protective policies are crucial steps toward reducing the health threats of nanoparticles, thereby maximizing their therapeutic advantages.

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.

Sulfur quantum dots as sustainable materials for biomedical applications: Current trends and future perspectives

Discovered over a decade ago, sulfur quantum dots (SQDs) have rapidly emerged as a sustainable, safe, and inexpensive quantum material. Sustainably synthesizing SQDs using sublimed sulfur powders, typically produced as waste in industrial petrochemical refining processes, has attracted researchers to use these functional quantum materials in various research fields. SQDs quickly found applications in various research fields, such as electronics, environmental sensing, food packaging, and biomedical engineering. Although low production yields, time-consuming and energy-intensive synthetic methods, and low photoluminescence quantum yield (PLQY) have been some problems, researchers have found ways to improve synthetic methods, develop passivating agents, and systematically modify reaction schemes and energy sources to achieve large-scale synthesis of stable SQDs with high PLQY. Nonetheless, SQDs have succeeded tremendously in biomedical and related applications due to their low toxicity, antibacterial and antioxidant properties, biocompatibility, appropriate cellular uptake, and photoluminescent properties. Although the bioimaging applications of SQDs have been extensively studied, their other reported properties indicate their suitability for use as antimicrobial agents, free radical scavengers, and drug carriers in other biomedical applications, such as tissue regeneration, wound healing, and targeted drug delivery.

Nanoassemblies of heptamethine cyanine dye-initiated poly(amino acid) enhance ROS generation for effective antitumour phototherapy

Phototherapy shows great potential for pinpoint tumour treatment. Heptamethine cyanine dyes like IR783 have high potential as agents for antitumour phototherapy due to their inherent tumour targeting ability, though their effectiveness in vivo is unsatisfactory for clinical translation. To overcome this limitation, we present an innovative strategy involving IR783-based polymeric nanoassemblies that improve the dye's performance as an antitumoural photosensitizer. In the formulation, IR783 is modified with cysteamine and used to initiate the ring-opening polymerization (ROP) of the N-carboxyanhydride of benzyl-L-aspartate (BLA), resulting in IR783-installed poly(BLA). Compared to free IR783, the IR783 dye in the polymer adopts a twisted molecular conformation and tuned electron orbital distribution, remarkably enhancing its optical properties. In aqueous environments, the polymers spontaneously assemble into nanostructures with 60 nm diameter, showcasing surface-exposed IR783 dyes that function as ligands for cancer cell and mitochondria targeting. Moreover, the nanoassemblies stabilized the dyes and enhanced the generation of reactive oxygen species (ROS) upon laser irradiation. Thus, in murine tumor models, a single injection of the nanoassemblies with laser irradiation significantly inhibits tumour growth with no detectable off-target toxicity. These findings highlight the potential for improving the performance of heptamethine cyanine dyes in antitumor phototherapy through nano-enabled strategies.

Targeted Thrombolysis with Magnetic Nanotherapeutics: A Translational Assessment

Plasminogen activators, such as recombinant tissue-type plasminogen activators (rtPAs), while effective in treating thromboembolic diseases, often induce hemorrhagic complications due to non-specific enzyme activities in the systemic circulation. This study evaluated the targeting efficiency, efficacy, biodistribution, and potential toxicity of a rtPA covalently attached to chitosan-coated magnetic nanoparticles (chitosan-MNP-rtPA). The thrombolytic activity of a chitosan-MNP-rtPA was preserved by protection from an endogenous plasminogen activator inhibitor-1 (PAI-1) in whole blood and after circulation in vivo, as examined by thromboelastometry. Single-photon emission computed tomography (SPECT) demonstrated real-time retention of a 99mTc-MNP-rtPA induced by magnet application in a rat embolic model; an 80% reduction in rtPA dosage for a chitosan-MNP-rtPA with magnetic guidance was shown to restore blood flow. After treatment, iron deposition was observed in the reticuloendothelial systems, with portal edema and neutrophil infiltration in the liver at a ten-fold higher dose but not the regular dose. Nevertheless, no liver or renal toxicity was observed at this higher dose. In conclusion, the liver may still be the major deposit site of rtPA nanocomposites after targeted delivery; chitosan-coated MNPs are potentially amenable to target therapeutics with parenteral administration.

Functionalization of 68Ga-Radiolabeled Nanodiamonds with Octreotide Does Not Improve Tumor-Targeting Capabilities

Nanodiamonds (NDs) are emerging as a novel nanoparticle class with growing interest in medical applications. The surface coating of NDs can be modified by attaching binding ligands or imaging probes, turning them into multi-modal targeting agents. In this investigation, we assessed the targeting efficacy of octreotide-functionalized 68Ga-radiolabelled NDs for cancer imaging and compared it with the tumor uptake using [68Ga]Ga-DOTA-TOC. In vivo studies in mice bearing AR42J tumors demonstrated the highest accumulation of the radiolabeled functionalized NDs in the liver and spleen, with relatively low tumor uptake compared to [68Ga]Ga-DOTA-TOC. Our findings suggest that, within the scope of this study, functionalization did not enhance the tumor-targeting capabilities of NDs.

Nanodiamonds: Next generation nano-theranostics for cancer therapy

Cancer remains a leading global cause of mortality, demanding early diagnosis and effective treatment. Traditional therapeutic methods often fall short due to their need for more specificity and systemic toxicity. In this challenging landscape, nanodiamonds (ND) emerge as a potential solution, mitigating the limitations of conventional approaches. ND are tiny carbon particles that mimic traditional diamonds chemical stability and hardness and harness nanomaterials' advantages. ND stands out for the unique properties that make them promising nanotheranostics candidates, combining therapeutic and imaging capabilities in one platform. Many of these applications depend on the design of the particle's surface, as the surface's role is crucial in transporting bioactive molecules, preventing aggregation, and building composite materials. This review delves into ND's distinctive features, structural and optical characteristics, and their profound relevance in advancing cancer diagnosis and treatment methods. The report delves into how these exceptional ND properties drive the development of state-of-the-art techniques for precise tumor targeting, boosting the effectiveness of chemotherapy as a chemosensitizer, harnessing immunotherapy strategies, facilitating precision medicine, and creating localized microfilm devices for targeted therapies.

Immunosuppressive enzyme-responsive nanoparticles for enhanced accumulation in liver allograft to overcome acute rejection

Acute rejection is a life-threatening complication after liver transplantation. Immunosuppressants such as tacrolimus are used to inhibit acute rejection of liver grafts in clinic. However, inefficient intragraft accumulation may reduce the therapeutic outcomes of tacrolimus. Here, an enzyme-responsive nanoparticle is developed to selectively enhance the accumulation of tacrolimus in liver allograft through enzyme-induced aggregation to refine immunotherapeutic efficacy of tacrolimus. The nanoparticles are composed of amphiphilic tacrolimus prodrugs synthesized by covalently conjugating tacrolimus and matrix metalloproteinase 9 (MMP9)-cleavable peptide-containing methoxy poly (ethylene glycol) to poly (l-glutamic acid). Upon exposure to MMP9, which is overexpressed in rejected liver allografts, the nanoparticles undergo a morphological transition from spherical micellar nanoparticles to microscale aggregate-like scaffolds. Intravenous administration of MMP9-responsive nanoparticles into a rat model of acute liver graft rejection results in enhanced nanoparticle accumulation in allograft as compared to nonresponsive nanoparticles. Consequently, the MMP9-responsive nanoparticles significantly inhibit intragraft inflammatory cell infiltration and proliferation, maintain intragraft immunosuppressive environment, alleviate graft damage, improve liver allograft function, abate weight loss and prolong recipient survival. This work proves that morphology-switchable enzyme-responsive nanoparticles represent an innovative strategy for selectively enhancing intragraft accumulation of immunosuppressive agents to improve treatment of liver allograft rejection.

Nanoengineered Polymeric RNA Nanoparticles for Controlled Biodistribution and Efficient Targeted Cancer Therapy

RNA nanotechnology, including rolling circle transcription (RCT), has gained increasing interest as a fascinating siRNA delivery nanoplatform for biostable and tumor-targetable RNA-based therapies. However, due to the lack of fine-tuning technologies for RNA nanostructures, the relationship between physicochemical properties and siRNA efficacy of polymeric siRNA nanoparticles (PRNs) with different sizes has not yet been fully elucidated. Herein, we scrutinized the effects of size/surface chemistry-tuned PRNs on the biological and physiological interactions with tumors. PRNs with adjusted size and surface properties were prepared using sequential engineering processes: RCT, condensation, and nanolayer deposition of functional biopolymers. Through the RCT process, nanoparticles of three sizes with a diameter of 50-200 nm were fabricated and terminated with three types of biopolymers: poly-l-lysine (PLL), poly-l-glutamate (PLG), and hyaluronic acid (HA) for different surface properties. Among the PRNs, HA-layered nanoparticles with a diameter of ∼200 nm exhibited the most effective systemic delivery, resulting in superior anticancer effects in an orthotopic breast tumor model due to the CD44 receptor targeting and optimized nanosized structure. Depending on the type of PRNs, the in vivo siRNA delivery with protein expression inhibition differed by up to approximately 20-fold. These findings indicate that the types of layered biopolymers and the PRNs size mediate efficient polymeric siRNA delivery to the targeted tumors, resulting in high RNAi-induced therapeutic efficacy. This RNA-nanotechnology-based size/surface editing can overcome the limitations of siRNA therapeutics and represents a potent built-in module method to design RNA therapeutics tailored for targeted cancer therapy.

Strategies to address key challenges of metallacycle/metallacage-based supramolecular coordination complexes in biomedical applications

Owing to their capacity for dynamically linking two or more functional molecules, supramolecular coordination complexes (SCCs), exemplified by two-dimensional (2D) metallacycles and three-dimensional (3D) metallacages, have gained increasing significance in biomedical applications. However, their inherent hydrophobicity and self-assembly driven by heavy metal ions present common challenges in their applications. These challenges can be overcome by enhancing the aqueous solubility and in vivo circulation stability of SCCs, alongside minimizing their side effects during treatment. Addressing these challenges is crucial for advancing the fundamental research of SCCs and their subsequent clinical translation. In this review, drawing on extensive contemporary research, we offer a thorough and systematic analysis of the strategies employed by SCCs to surmount these prevalent yet pivotal obstacles. Additionally, we explore further potential challenges and prospects for the broader application of SCCs in the biomedical field.

Unlocking the potential of tumor-derived DNA in urine for cancer detection: methodological challenges and opportunities

High cancer mortality rates and the rising cancer burden worldwide drive the development of innovative methods in order to advance cancer diagnostics. Urine contains a viable source of tumor material and allows for self-collection from home. Biomarker testing in this liquid biopsy represents a novel approach that is convenient for patients and can be effective in detecting cancer at a curable stage. Here, we set out to provide a detailed overview of the rationale behind urine-based cancer detection, with a focus on non-urological cancers, and its potential for cancer diagnostics. Moreover, evolving methodological challenges and untapped opportunities for urine biomarker testing are discussed, particularly emphasizing DNA methylation of tumor-derived cell-free DNA. We also provide future recommendations for technical advancements in urine-based cancer detection and elaborate on potential mechanisms involved in the transrenal transport of cell-free DNA.

Pharmacokinetics and Biodistribution of Phages and their Current Applications in Antimicrobial Therapy

Antimicrobial resistance remains a critical global health concern, necessitating the investigation of alternative therapeutic approaches. With the diminished efficacy of conventional small molecule drugs due to the emergence of highly resilient bacterial strains, there is growing interest in the potential for alternative therapeutic modalities. As naturally occurring viruses of bacteria, bacteriophage (or phage) are being re-envisioned as a platform to engineer properties that can be tailored to target specific bacterial strains and employ diverse antibacterial mechanisms. However, limited understanding of key pharmacological properties of phage is a major challenge to translating its use from preclinical to clinical settings. Here, we review modern advancements in phage-based antimicrobial therapy and discuss the in vivo pharmacokinetics and biodistribution of phage, addressing critical challenges in their application that must be overcome for successful clinical implementation.

Anti-stromal nanotherapeutics for hepatocellular carcinoma

Hepatocellular carcinoma (HCC), the most commonly diagnosed primary liver cancer, has become a leading cause of cancer-related death worldwide. Accumulating evidence confirms that the stromal constituents within the tumor microenvironment (TME) exacerbate HCC malignancy and set the barriers to current anti-HCC treatments. Recent developments of nano drug delivery system (NDDS) have facilitated the application of stroma-targeting therapeutics, disrupting the stromal TME in HCC. This review discusses the stromal activities in HCC development and therapy resistance. In addition, it addresses the delivery challenges of NDDS for stroma-targeting therapeutics (termed anti-stromal nanotherapeutics in this review), and provides recent advances in anti-stromal nanotherapeutics for safe, effective, and specific HCC therapy.

Designing Gold Nanoparticles for Precise Glioma Treatment: Challenges and Alternatives

Glioblastoma multiforme (GBM) is a glioma and the most aggressive type of brain tumor with a dismal average survival time, despite the standard of care. One promising alternative therapy is boron neutron capture therapy (BNCT), which is a noninvasive therapy for treating locally invasive malignant tumors, such as glioma. BNCT involves boron-10 isotope capturing neutrons to form boron-11, which then releases radiation directly into tumor cells with minimal damage to healthy tissues. This therapy lacks clinically approved targeted blood-brain-barrier-permeating delivery vehicles for the central nervous system (CNS) entry of therapeutic boron-10. Gold nanoparticles (GNPs) are selective and effective drug-delivery vehicles because of their desirable properties, facile synthesis, and biocompatibility. This review discusses biomedical/therapeutic applications of GNPs as a drug delivery vehicle, with an emphasis on their potential for carrying therapeutic drugs, imaging agents, and GBM-targeting antibodies/peptides for treating glioma. The constraints of GNP therapeutic efficacy and biosafety are discussed.

Nanodiamond-Enhanced Magnetic Resonance Imaging

Nanodiamonds (ND) hold great potential for diverse applications due to their biocompatibility, non-toxicity, and versatile functionalization. Direct visualization of ND by means of non-invasive imaging techniques will open new venues for labeling and tracking, offering unprecedented and unambiguous detection of labeled cells or nanodiamond-based drug carrier systems. The structural defects in diamonds, such as vacancies, can have paramagnetic properties and potentially act as contrast agents in magnetic resonance imaging (MRI). The smallest nanoscale diamond particles, detonation ND, are reported to effectively reduce longitudinal relaxation time T1 and provide signal enhancement in MRI. Using in vivo, chicken embryos, direct visualization of ND is demonstrated as a bright signal with high contrast to noise ratio. At 24 h following intravascular application marked signal enhancement is noticed in the liver and the kidneys, suggesting uptake by the phagocytic cells of the reticuloendothelial system (RES), and in vivo labeling of these cells. This is confirmed by visualization of nanodiamond-labeled macrophages as positive (bright) signal, in vitro. Macrophage cell labeling is not associated with significant increase in pro-inflammatory cytokines or marked cytotoxicity. These results indicate nanodiamond as a novel gadolinium-free contrast-enhancing agent with potential for cell labeling and tracking and over periods of time.

Promoting collateral formation in type 2 diabetes mellitus using ultra-small nanodots with autophagy activation and ROS scavenging

BACKGROUND

Impaired collateral formation is a major factor contributing to poor prognosis in type 2 diabetes mellitus (T2DM) patients with atherosclerotic cardiovascular disease. However, the current pharmacological treatments for improving collateral formation remain unsatisfactory. The induction of endothelial autophagy and the elimination of reactive oxygen species (ROS) represent potential therapeutic targets for enhancing endothelial angiogenesis and facilitating collateral formation. This study investigates the potential of molybdenum disulfide nanodots (MoS2 NDs) for enhancing collateral formation and improving prognosis.

RESULTS

Our study shows that MoS2 NDs significantly enhance collateral formation in ischemic tissues of diabetic mice, improving effective blood resupply. Additionally, MoS2 NDs boost the proliferation, migration, and tube formation of endothelial cells under high glucose/hypoxia conditions in vitro. Mechanistically, the beneficial effects of MoS2 NDs on collateral formation not only depend on their known scavenging properties of ROS (H2O2, •O2-, and •OH) but also primarily involve a molecular pathway, cAMP/PKA-NR4A2, which promotes autophagy and contributes to mitigating damage in diabetic endothelial cells.

CONCLUSIONS

Overall, this study investigated the specific mechanism by which MoS2 NDs mediated autophagy activation and highlighted the synergy between autophagy activation and antioxidation, thus suggesting that an economic and biocompatible nano-agent with dual therapeutic functions is highly preferable for promoting collateral formation in a diabetic context, thus, highlighting their therapeutic potential.

Advances in screening hyperthermic nanomedicines in 3D tumor models

Hyperthermic nanomedicines are particularly relevant for tackling human cancer, providing a valuable alternative to conventional therapeutics. The early-stage preclinical performance evaluation of such anti-cancer treatments is conventionally performed in flat 2D cell cultures that do not mimic the volumetric heat transfer occurring in human tumors. Recently, improvements in bioengineered 3D in vitro models have unlocked the opportunity to recapitulate major tumor microenvironment hallmarks and generate highly informative readouts that can contribute to accelerating the discovery and validation of efficient hyperthermic treatments. Leveraging on this, herein we aim to showcase the potential of engineered physiomimetic 3D tumor models for evaluating the preclinical efficacy of hyperthermic nanomedicines, featuring the main advantages and design considerations under diverse testing scenarios. The most recent applications of 3D tumor models for screening photo- and/or magnetic nanomedicines will be discussed, either as standalone systems or in combinatorial approaches with other anti-cancer therapeutics. We envision that breakthroughs toward developing multi-functional 3D platforms for hyperthermia onset and follow-up will contribute to a more expedited discovery of top-performing hyperthermic therapies in a preclinical setting before their in vivo screening.

Ultrasmall metal alloy nanozymes mimicking neutrophil enzymatic cascades for tumor catalytic therapy

Developing strategies that emulate the killing mechanism of neutrophils, which involves the enzymatic cascade of superoxide dismutase (SOD) and myeloperoxidase (MPO), shows potential as a viable approach for cancer therapy. Nonetheless, utilizing natural enzymes as therapeutics is hindered by various challenges. While nanozymes have emerged for cancer treatment, developing SOD-MPO cascade in one nanozyme remains a challenge. Here, we develop nanozymes possessing both SOD- and MPO-like activities through alloying Au and Pd, which exhibits the highest cascade activity when the ratio of Au and Pd is 1:3, attributing to the high d-band center and adsorption energy for superoxide anions, as determined through theoretical calculations. The Au1Pd3 alloy nanozymes exhibit excellent tumor therapeutic performance and safety in female tumor-bearing mice, with safety attributed to their tumor-specific killing ability and renal clearance ability caused by ultrasmall size. Together, this work develops ultrasmall AuPd alloy nanozymes that mimic neutrophil enzymatic cascades for catalytic treatment of tumors.

Effects of Drug Conjugation on the Biological Activity of Single-Chain Nanoparticles

The field of single-chain nanoparticles (SCNPs) continues to mature, and an increasing range of reports have emerged that explore the application of these small nanoparticles. A key application for SCNPs is in the field of drug delivery, and recent work suggests that SCNPs can be readily internalized by cells. However, limited attention has been directed to the delivery of small-molecule drugs using SCNPs. Moreover, studies on the physicochemical effects of drug loading on SCNP performance is so far missing, despite the accepted view that such small nanoparticles should be significantly affected by the drug loading content. To address this gap, we prepared a library of SCNPs bearing different amounts of a covalently conjugated therapeutic drug-sulfasalazine (SSZ). We evaluated the impact of the conjugated drug loading on both the synthesis and biological activity of SCNPs on pancreatic cancer cells (AsPC-1). Our results reveal that covalent drug conjugation to the side chains of the SCNP polymer precursor interferes with chain collapse and cross-linking, which demands optimization of reaction conditions to reach high degrees of cross-linking efficiencies. Small-angle neutron scattering and diffusion-ordered spectroscopy nuclear magnetic resonance (DOSY NMR) analyses reveal that SCNPs with a higher drug loading display larger sizes and looser structures, as well as increased hydrophobicity associated with a higher SSZ content. Increased SSZ loading led to reduced cellular uptake when assessed in vitro, whereby SCNP aggregation on the surface of AsPC-1 cells led to reduced toxicity. This work highlights the effects of drug loading on the drug delivery efficiency and biological behavior of SCNPs.

Design of Liquid Formulation Based on F127-Loaded Natural Dimeric Flavonoids as a New Perspective Treatment for Leishmaniasis

Infectious and Parasitic Diseases (IPD) remain a challenge for medicine due to several interconnected reasons, such as antimicrobial resistance (AMR). American tegumentary leishmaniasis (ATL) is an overlooked IPD causing persistent skin ulcers that are challenging to heal, resulting in disfiguring scars. Moreover, it has the potential to extend from the skin to the mucous membranes of the nose, mouth, and throat in both humans and various animals. Given the limited effectiveness and AMR of current drugs, the exploration of new substances has emerged as a promising alternative for ATL treatment. Arrabidaea brachypoda (DC). Bureau is a native Brazilian plant rich in dimeric flavonoids, including Brachydin (BRA), which displays antimicrobial activity, but still little has been explored regarding the development of therapeutic formulations. In this work, we present the design of a low-cost liquid formulation based on the use of Pluronic F127 for encapsulation of high BRA concentration (LF-B500). The characterization techniques revealed that BRA-loaded F127 micelles are well-stabilized in an unusual worm-like form. The in vitro cytotoxicity assay demonstrated that LF-B500 was non-toxic to macrophages but efficient in the inactivation of forms of Leishmania amazonensis promastigotes with IC50 of 16.06 µg/mL. The results demonstrated that LF-B500 opened a new perspective on the use of liquid formulation-based natural products for ATL treatment.