Despite the increasing global prevalence of neurological disorders, the development of nanoparticle (NP) technologies for brain-targeted therapies confronts considerable challenges. One of the key obstacles in treating brain diseases is the blood-brain barrier (BBB), which restricts the penetration of NP-based therapies into the brain. To address this issue, NPs can be installed with specific ligands or bioengineered to boost their precision and efficacy in targeting brain-diseased cells by navigating across the BBB, ultimately improving patient treatment outcomes. At the outset of this review, we highlighted the critical role of ligand-functionalized or bioengineered NPs in treating brain diseases from a clinical perspective. We then identified the key obstacles and challenges NPs encounter during brain delivery, including immune clearance, capture by the reticuloendothelial system (RES), the BBB, and the complex post-BBB microenvironment. Following this, we overviewed the recent progress in NPs engineering, focusing on ligand-functionalization or bionic designs to enable active BBB transcytosis and targeted delivery to brain-diseased cells. Lastly, we summarized the critical challenges hindering clinical translation, including scalability issues and off-target effects, while outlining future opportunities for designing cutting-edge brain delivery technologies.

Targeted systemic mRNA delivery to extrahepatic tissues remains a formidable challenge, especially in the absence of targeting ligands on lipid nanoparticles. In this study, we introduce a series of dimethylamino-based ionizable lipidoids (DMA-Lipidoids) engineered for selective mRNA delivery to the spleen. Using a combinatorial approach, we synthesized 48 chemically distinct lipidoids by pairing four DMA-containing amine heads with 12 newly designed hyperbranched tails. Remarkably, lipidoids with tails H228, H226x, H246x, and H446x demonstrated exceptional spleen-targeting efficiency. To refine the lipidoid design, we constructed and screened a secondary library of 36 lipidoids containing DMA analogues. Through this two-round screening process, we identified lipidoids with both high potency and spleen selectivity. The lead candidate, DMA4-H228, achieved precise delivery of ovalbumin mRNA to antigen-presenting cells (APCs), driving interferon-α (IFN α) production and APC activation. This robust immune response effectively inhibited tumor growth. Overall, these innovative DMA-lipidoids demonstrate strong spleen-targeting capabilities, offering a transformative platform for mRNA vaccine development.

Lysosomes present a major barrier to efficient mRNA delivery. Existing strategies primarily depend on lysosomal disruption, which is inefficient and carries a risk of cytolysis. We propose an Autonomic Lysosomal Escape (ALE) strategy, in which sialic acid (SA) modification enables over 90 % of LNPs to successfully escape from lysosomes by inducing cells to spontaneously reduce lysosome generation. The SA modification enhances the transfection efficiency of LNPs administered via intravenous injection, intramuscular injection, and inhalation, demonstrating the broad applicability. The structure of cleavable PEG-lipids was optimized using a newly developed method, termed Systematic Evaluation of LNPs' Efficiency by Cumulative Tests (SELECT). The results showed that polyethylene glycol 2000-cholesterol hemisuccinate (Ps) is the optimal candidate for co-modification with SA. The resulting LNPs co-modified with SA and Ps (SAPs@LNPs) completely eradicated TC-1 tumors and induced humoral immune memory. Combining SA-modified doxorubicin liposomes (DOX-SL) further accelerates tumor elimination, while licensed PEGylated liposomal doxorubicin (Caelyx) impairs the efficacy of mRNA vaccines. This difference stems from DOX-SL's selective depletion of tumor-associated immune cells (TAICs) and the nonspecific cytotoxicity of Caelyx. These findings suggest that combining Caelyx with mRNA vaccines should be approached with caution. Our study also highlights the key roles of humoral immune memory and natural killer cell-driven antibody-dependent cellular cytotoxicity (ADCC) in tumor eradication, and incorporating them into the cancer immune cycle further refines this theory.

Liver macrophages capture circulating nanoparticles and reduce their delivery to target organs. Serum proteins adsorb to the nanoparticle surface after administration. However, the adsorbed serum proteins and their cognate cell receptors for removing nanoparticles from the bloodstream have not been linked. Here we use a multi-omics strategy to identify the adsorbed serum proteins binding to specific liver macrophage receptors. We discovered six absorbed serum proteins that bind to two liver macrophage receptors. Nanoparticle physicochemical properties can affect the degree of the six serum proteins adsorbing to the surface, the probability of binding to cell receptors and whether the liver removes the nanoparticle from circulation. Identifying the six adsorbed proteins allowed us to engineer decoy nanoparticles that prime the liver to take up fewer therapeutic nanoparticles, enabling more nanoparticles for targeting extrahepatic tissues. Elucidating the molecular interactions governing the nanoparticle journey in vivo will enable us to control nanoparticle delivery to diseased tissues.

Lipid-based nanoparticles, including liposomes and lipid nanoparticles (LNPs), make up an important class of drug delivery systems. Their modularity enables encapsulation of a wide range of therapeutic cargoes, their ease of functionalization allows for incorporation of targeting motifs and anti-fouling coatings, and their scalability facilitates rapid translation to the clinic. While the discovery and early understanding of lipid-based nanoparticles is heavily rooted in biology, formulation development has largely focused on materials properties, such as how liposome and lipid nanoparticle composition can be altered to maximize drug loading, stability and circulation. To achieve targeted delivery and enable improved accumulation of therapeutics at target tissues or disease sites, emphasis is typically placed on the use of external modifications, such as peptide, protein, and polymer motifs. However, these approaches can increase the complexity of the nanocarrier and complicate scale up. In this review, we focus on how our understanding of lipid structure and function in biological contexts can be used to design intrinsically functional and targeted nanocarriers. We highlight formulation-based strategies, such as the incorporation of bioactive lipids, that have been used to modulate liposome and lipid nanoparticle properties and improve their functionality while retaining simple nanocarrier designs. We also highlight classes of naturally occurring lipids, their functions, and how they have been incorporated into lipid-based nanoparticles. We will additionally position these approaches into the historical context of both liposome and LNP development.

Nanoparticle (NP) uptake by macrophages and their accumulation in undesired organs such as the liver and spleen constitute a major barrier to the effective delivery of NPs to targeted tissues for bioimaging and therapeutics. Surface functionalization with polyethylene glycol (PEG) has been demonstrated to be a promising strategy to limit NP sequestration, although its longitudinal stability under physiological conditions and impact on the NP biodistribution have not been investigated with an in vivo quantitative approach. X-ray fluorescence (XRF) imaging has been employed to noninvasively map the in vivo biodistribution of purposely designed molybdenum-based contrast agents, leading to submillimeter resolution, elemental specificity, and high penetration depth. In the present work, we design a stepwise layering approach for NP synthesis to investigate the role of chemisorbed and physisorbed PEG on silica-coated molybdenum-based contrast agents in affecting their in vivo biodistribution, using whole-body XRF imaging. Comparative quantitative in vivo studies indicated that physisorbed PEG (1.5 kDa) did not substantially affect the biodistribution, while the chemisorption route with mPEG-Si (6-9 PEG units) led to significant macroscopic variations in the biodistribution, leading to a reduction in NP uptake by the liver. Furthermore, the results highlighted the major role of the spleen in compensating for the limited sequestration by the liver, microscopically validated with a multiscale imaging approach with fluorophore doping of the silica shell. These findings demonstrated the promising role of XRF imaging for the rapid assessment of surface-functionalized contrast agents with whole-body in vivo quantitative pharmacokinetic studies, establishing the groundwork for developing strategies to identify and bypass undesired NP uptake.

The active transport and retention principle is an alternative mechanism to the enhanced permeability and retention effect for explaining nanoparticle tumour delivery. It postulates that nanoparticles actively transport across tumour endothelial cells instead of passively moving through gaps between these cells. How nanoparticles transport across tumour endothelial cells remains unknown. Here we show that nanoparticles cross tumour endothelial cells predominantly using the non-receptor-based macropinocytosis pathway. We discovered that tumour endothelial cell membrane ruffles capture circulating nanoparticles, internalize them in intracellular vesicles and release them into the tumour interstitium. Tumour endothelial cells have a higher membrane ruffle density than healthy endothelium, which may partially explain the elevated nanoparticle tumour accumulation. Receptor-based endocytosis pathways such as clathrin-mediated endocytosis contribute to nanoparticle transport to a lesser extent. Nanoparticle size determines the degree of contribution for each pathway. Elucidating the nanoparticle transport mechanism is crucial for developing strategies to control nanoparticle tumour delivery.

Contrast agents (CAs) are essential in biomedical imaging to aid in the diagnosis and therapy monitoring of disease. However, they are typically restricted to one imaging modality and have fixed properties such as size, shape, toxicity profile, or photophysical characteristics, which hampers a comprehensive view of biological processes. Herein, rationally designed dye assemblies are introduced as a unique CA platform for simultaneous multimodal and multiscale biomedical imaging. To this end, a series of amphiphilic aza-BODIPY dyes are synthesized with varying hydrophobic domains (C1, C8, C12, and C16) that self-assemble in aqueous media into nanostructures of tunable size (50 nm-1 µm) and photophysical properties. While C1 exhibits oblique-type exciton coupling and negligible emission, C8-C16 bearing longer alkyl chains undergo J-type aggregation with NIR absorption and emission and excellent photoacoustic properties. Given these advantageous features, aza-BODIPY specific, semi-quantitative fluorescence reflectance and photoacoustic imaging both in vitro and in vivo are established. Additionally, in vitro cell viability as well as murine in vivo biodistribution analysis with ex vivo validation showed excellent biocompatibility and a size-dependent biodistribution of nanostructures to different organ beds. These results broaden the scope of aqueous self-assembly to multimodal imaging and highlight its great potential for rationalizing numerous biomedical questions.

Nanomaterial-mediated macrophage immune response plays a crucial role in bone regeneration microenvironment. Mesoporous silica nanoparticles are widely used as nano-drug carriers, imaging agents, and bioactivity regulators for potential tissue regeneration. It is known that surface topography features of nanomaterials play an important regulatory role in the immune response. In this study, it was found that the pollen-like surface morphology of mesoporous silica nanoparticles (PMSNs) inhibited the expression of pro-inflammatory markers at gene and protein levels in macrophages (RAW 264.7 cells) compared to the smooth surface morphology of mesoporous silica nanoparticles (MSNs). Scanning electron microscopy images showed distinct macrophage membrane surface binding patterns of MSNs and PMSNs. MSNs were more evenly dispersed across the macrophage cell membrane, while PMSNs were aggregated on the membrane and prevented the M1 polarization of macrophages. PMSNs-induced macrophage anti-inflammatory responses were associated with up-regulation of the cell surface receptor CD28 and inhibition of ERK phosphorylation. TEM images showed that macrophages phagocytosed both MSNs and PMSNs while inhibiting nanoparticle phagocytosis did not affect the expression of anti-inflammatory genes and proteins. Moreover, PMSNs-induced conditioned medium from macrophages promoted osteogenic differentiation of mouse bone marrow-derived stromal cells (mBMSCs), evidenced by increased mineralization and osteogenic marker BMP2 expression via Alizarin Red S and LSCM assays compared to MSNs-induced conditioned medium. Moreover, a lipopolysaccharide (LPS)-induced osteolysis model in mouse cranial bone further demonstrated that PMSNs prevent bone resorption by mitigating LPS-induced inflammation. Our results revealed that PMSNs-mediated macrophage immunomodulation promotes bone regeneration via surface topology-related physical contact cues. STATEMENT OF SIGNIFICANCE: Nanomaterials have been widely used in bone regeneration. The immune response of macrophages induced by nanomaterials, plays a crucial role in bone regeneration. However, most nanomaterial immunomodulatory research focus on macrophage internalization or phagocytosis. The early contact between the cell membrane and nanomaterials is often easily overlooked. To clarify how early contact between nanomaterial-cell membrane regulates macrophage immune response. We developed MSN particles with special pollen-like surface morphology and studied the impact of nanoparticle morphology on the early contact between materials and macrophage cell membranes, as well as the subsequent impact on macrophage immune response and bone regeneration and related regulatory mechanisms. The results can provide new guidance for the design and development of osteoimmunomodulatory nanomaterials.

Understanding nanoparticle interactions with cells is fundamental to designing them for medical applications. Nanoparticles must interface with the cell surface to be bound and taken up. The glycocalyx is a carbohydrate layer coating the cell surface, rendering it negatively charged. Many researchers have noted that the glycocalyx affects nanoparticle uptake, but the mechanism remains unknown, Here, we investigate the interaction between the glycocalyx and nanoparticles at the cell surface in different cell types. The glycocalyx reduced the interactions between the nanoparticles and cells, thereby reducing cellular access, binding, and uptake. The magnitude of the effect is dependent on the nanoparticle charge. Fine-tuning the charge of nanoparticles can enhance the specificity of nanoparticle targeting. Understanding the role of the glycocalyx in nano-bio interactions will allow researchers to control the interactions of nanoparticles with the cell surface.

Nanoparticles (NPs) have been extensively researched for targeted diagnostic imaging and drug delivery, yet their clinical translation remains limited, with only a few achieving Food and Drug Administration approval. This limited success is primarily due to challenges in achieving precise organ- or tissue-specific targeting, which arise from off-target tissue accumulation and suboptimal clearance profiles. Herein we examine the critical role of physicochemical properties, including size, surface charge, shape, elasticity, hardness, and density, in governing the biodistribution, targetability, and clearance of NPs. We highlight recent advancements in engineering NPs for targeted imaging and drug delivery, showcasing both significant progress and the remaining challenges in the field of nanomedicine. Additionally, we discuss emerging tools and technologies that are being developed to address these challenges. Based on recent insights from materials science, biomedical engineering, computational biology, and clinical research, we propose key design considerations for next-generation nanomedicines with enhanced organ selectivity.

Acute liver failure (ALF) is a life-threatening disease featuring comprehensive inflammatory response and metabolic disorders in which macrophages exert central roles. A glucose metabolism mediator of macrophages, itaconate, has demonstrated potent anti-inflammatory efficacy in various diseases, implying that itaconate could work in treating ALF. However, systemic administration of itaconate may lead to immune disorder, making targeting the delivery of itaconate to the liver lesion area highly important. Herein, a liposomal nanodrug incorporating itaconate is developed, and its potential in treating acute liver failure in an ALF murine model established by LPS/D-GalN administration is tested. The nanodrug shows preferential liver accumulation to effectively alleviate LPS/D-GalN-induced hepatic histopathological injury by decreasing oxidative stress. Moreover, it reprograms the glucose metabolism of macrophages, resulting in macrophage repolarization toward the anti-inflammatory phenotype. Furthermore, western-blot and immunohistochemical assays verifies that the nanodrug may inhibit aerobic glycolysis of macrophages in an NRF2 and STING-dependent manner. These results underline the promise of the nanodrug for ALF treatment by reprogramming glucose metabolism.

Due to limited light penetration and dependence on oxygen, photodynamic therapy (PDT) is typically restricted to treating shallow tissues. Developing strategies to overcome these limitations and effectively using PDT for tumor treatment is a significant yet unresolved challenge. In this study, we present a smart approach combining a wireless-charged LED (wLED) with a type I aggregation-induced emission photosensitizer, MeOTTMN, to address both light penetration and tumor hypoxia issues simultaneously. MeOTTMN, characterized by twisted molecular architecture and strong intramolecular electron donor-acceptor interaction, produces high levels of hydroxyl and superoxide radicals and emits near-infrared light in its aggregated state, thus facilitating fluorescence imaging-guided PDT once formulated into nanoparticles. The inhibition of breast cancer xenografts provides compelling evidence of the treatment efficacy of type I PDT irradiated through an implantable wLED. This strategy provides a conceptual and practical paradigm to overcome key clinical limitations of PDT, expanding possibilities for clinical translation.

Nanoparticles (NPs) are beneficial for delivery of drugs in a variety of settings, serving to protect their cargo and allow for sustained release. Polymeric NPs offer several advantages as therapeutics carriers due to their tunable characteristics like size and shape, ease of manufacturing, and biocompatibility. Despite this, there are no polymeric NPs that are approved for treatment of liver diseases. This is surprising since─when administered intravenously─the majority of NPs accumulate in cells in the liver. NP characteristics like size and surface charge can be altered to affect distribution to the liver, and even cellular distribution, but the conjugation of targeting ligands onto the NP surface for specific receptors on the cells is an important approach for enhancing cell specific delivery. Enhancing cell-specific targeting of conjugated NPs in the liver has two major hurdles: 1) avoiding accumulation of NPs in the liver resident macrophages known as Kupffer cells, which are optimized to phagocytose particulates, and 2) overcoming the transport barriers associated with architectural changes of the diseased liver. To identify the structures and mechanisms most important in NP design, NP administration during ex vivo perfusion (EVP)─achieved by anatomically isolating an organ by perfusing it outside the body─may be the most important and efficient approach. However, EVP is currently underutilized in the NP field, with limited research published on NPs delivered during liver EVP, and therefore representing an opportunity for future investigations.

Improvements in tumor therapy require a combination of strategies where targeted treatment is critical. We developed a new versatile nanoplatform, MA@E, that generates high levels of reactive oxygen species (ROS) with effective photothermal conversions in the removal of tumors. Enhanced stability liposomes were employed as carriers to facilitate the uniform distribution and stable storage of encapsulated gold nanorods (AuNRs) and Mn-MIL-100 metal-organic frameworks, with efficient delivery of MA@E to the cytoplasm. In the targeted phagocytosis of tumor cells, MA@E can effectively deplete the reduced glutathione (GSH) with increased hydroxyl radicals that combine with Mn2+ released from Mn-MIL-100 to trigger Fenton-like reactions, generating ROS that induces cell apoptosis. Exposure to near-infrared (NIR-II) irradiation results in a AuNRs-induced thermogenic effect that expedites the release of Mn2+ and promotes Fenton-like reactions, achieving increased production of •OH. In the murine tumor model, MA@E effectively removed the implanted tumor tissue within 2 days without any obvious toxic effects. This response is attributed to a synergism involving the photothermal capability of AuNRs and ROS chemodynamic treatment. The proposed MA@E provides a new approach to utilizing unstable nanomaterials in effective tumor therapy.

Gold nanomaterials have garnered significant attention in biomedicine owing to their tunable size and morphology, facile surface modification capabilities, and distinctive optical properties. The surface functionalization of these nanoparticles can enhance their safety and efficacy in nanomedical applications. In this study, we examined the biological effects of gold nanoparticles (GNPs) with three distinct surface modifications (polyethylene glycol, chitosan, and polyethylenimine) in murine models, elucidating their mechanisms of action on hepatic tissue at both the transcriptomic and metabolomic levels. Our findings revealed that PEG-modified GNPs did not significantly alter any major metabolic pathway. In contrast, CS-GNPs markedly affected the metabolic pathways of retinol, arachidonic acid, linoleic acid, and glycerophospholipids (FDR < 0.05). Similarly, PEI-GNPs significantly influenced the metabolic pathways of retinol, arachidonic acid, linoleic acid, and sphingolipids (FDR < 0.05). Through a comprehensive analysis of the regulatory information within these pathways, we identified phosphatidylcholine compounds as potential biomarkers that may underlie the differential biological effects of the three functionalized GNPs. These findings provide valuable experimental data for evaluating the biological safety of functionalized GNPs.

Various biological barriers hinder the effective use of administered nanoparticles, with the mononuclear phagocyte system (MPS) being a major obstacle to their in vivo efficacy. Glucose metabolism is an important factor for macrophages to perform MPS clearance in vivo. In this study, energy metabolism-blocking nanoparticles PEG-S-S-PLA@RGD @Dox@BAY876 (RPDB NPs) were developed to change drug distribution in the body, improving the efficacy of chemotherapy. First, BAY876 showed an excellent inhibition effects on macrophage energy metabolism in vitro. This inhibitory behavior of energy metabolism reduced the aggregation of nanoparticles in macrophages. Similarly, the migration capacity of macrophages was also limited by reduced energy metabolism. Second, the fluorescence distribution in the mice also showed that the fluorescence intensity of RPDB NPs in the liver was about 40% of that of RPD NPs, suggesting that reducing energy metabolism helps to downregulate the uptake of mononuclear phagocytic cell (MPS), and change the distribution of the drug in vivo. Furthermore, anti-tumor effects of RPDB NPs were evaluated both in vivo and in vitro. In vivo, RPDB nanomicelles inhibited breast cancer by up to 68.3%, higher than other administration groups. Moreover, the pathological section of tumor exhibited a significantly greater increase in cell apoptosis in RPDB NPs group. Hence, inhibition of macrophage energy metabolism is a promising approach to eliminate MPS effects, while also opening up a new window for the effective inhibition of tumors development and metastasis.

Tuberculosis is a serious infectious disease commonly treated with rifampicin (RIF), which has low water solubility and high permeability. Polymeric nanoparticles (PNs) are used for controlled drug delivery to improve drug efficacy. However, PNs can be easily expelled via pulmonary administration. Nano-embedded microparticles (NEMs) are designed to bypass pulmonary barriers. Cashew gum, a versatile heteropolysaccharide, was modified into phthalated cashew gum (PCG), which targets alveolar macrophages, to increase hydrophobicity and improve drug encapsulation efficiency. In this study, the PCG was successfully obtained. Polymeric nanoparticle (PN)-PCG-RIF was fabricated, and its performance characteristics were investigated. PN-PCG-RIF exhibits mucoadhesive properties. An in vitro release study showed the release of 66.57 % of RIF after 6 h. An in vitro cytotoxicity study in A549 cells showed that PN-PCG-RIF is cytocompatible. The cellular uptake study demonstrated efficient cellular internalization in J774 macrophages, which was attributed to the PCG composition binding to the galactose-type lectin C receptor (MGL-2/CD301b). NEM-RIF was optimized by the Box Behnken designer with a particle size of 240.80 nm, PdI of 0.185, and redispersion index of 1.63. Scanning electron microscopy revealed NEMs-RIF in the form of spherical agglomerates. Collectively, RIF-NEMs were successfully developed from PN-PCG-RIF, having potential for the treatment of tuberculosis.

The reactive oxygen species (ROS) amplification caused by inevitable plasma albumin encapsulation is still a challenge to circumvent the systemic adverse effects in the photodynamic therapy (PDT) process. Herein, a disulfide bond linked homodimer, Cy1280, which is modulated by albumin to accurately balance the fluorescence and ROS generation and exhibit a weak fluorescence and sealed PDT effect during blood circulation, is exploited. Cy1280 can be specifically internalized and dispersed at the tumor site via Organic Anion Transporter Proteins (OATPs) and thiol-disulfide exchange mediated synergistic uptake and activated after mild sunlight irradiation (100 ± 5 Klx) to sensitize neighboring oxygen in cellular mitochondria to execute direct protein dysfunction effect. The dynamic covalent chemistry (DCC) facilitates prolonged and sustained retention in tumors (>336 h) and demonstrates the efficacy of imaging-guided solid-tumor therapy in tumor-bearing BALB/C mice. This study resolves the inevitable stubborn impotent tumor penetration caused by bulky-sized nanoparticles and high interstitial pressure of tumor with synergistic uptake manner, the long-term circulation and sealed PDT manipulated with albumin also improve the whole body phototoxic symptom. The advantageous feature of Cy1280 provides a promising candidate for overcoming the off-target phototoxicity and inadequate accumulation challenges in clinical translation with photosensitizers (PSs).

Ribonucleic acid (RNA) nanocarriers, specifically lipid nanoparticles and polymeric nanoparticles, enable RNA transfection both in vitro and in vivo; however, only a small percentage of RNA endocytosed by a cell is delivered to the cytosolic machinery, minimizing its effect. RNA nanocarriers face two major obstacles after endocytosis: endosomal escape and RNA release. Overcoming both obstacles simultaneously is challenging because endosomal escape is usually achieved by using high positive charge to disrupt the endosomal membrane. However, this high positive charge typically also inhibits RNA release because anionic RNA is strongly bound to the nanocarrier by electrostatic interactions. Many nanocarriers address one over the other despite a growing body of evidence demonstrating that both are crucial for RNA transfection. In this review, we survey the various strategies that have been employed to accomplish both endosomal escape and RNA release with a focus on polymeric nanomaterials. We first consider the various requirements a nanocarrier must achieve for RNA delivery including protection from degradation, cellular internalization, endosomal escape, and RNA release. We then discuss current polymers used for RNA delivery and examine the strategies for achieving both endosomal escape and RNA release. Finally, we review various stimuli-responsive strategies for RNA release. While RNA release continues to be a challenge in achieving efficient RNA transfection, many new innovations in polymeric materials have elucidated promising strategies.

Triple-negative breast cancer (TNBC) is a highly aggressive subtype of breast cancer characterized by an extremely poor prognosis. Photoimmunotherapy has emerged as a promising strategy for the treatment of TNBC. This approach works by selectively destroying tumor cells, releasing tumor-associated antigens, activating the immune system, and effectively inhibiting tumor proliferation and metastasis. However, the majority of current phototheranostic approaches are hindered by limited tissue penetration in the first near-infrared (NIR-I) and ultraviolet-visible (UV-Vis) regions. Additionally, due to the lack of specific subcellular targets, it may be difficult to effectively treat deep-seated lesions with ambiguous and extensive boundaries caused by TNBC metastases. Consequently, the development of effective, deep-penetrating, organelle-targeted phototheranostics is essential for enhancing treatment outcomes in TNBC. This work proposes a novel molecular design strategy of NIR-II phototheranostics to realize planar rigid conjugation and alkyl chain functionalization. The di-hexaalkyl chains in a vertical configuration on the donor (4H-cyclopenta[2,1-b:3,4-b'] dithiophene) and shielding units (fluorene) are introduced to construct a S-D-A-D-S type NIR-II phototheranostics (IR-FCD). The planar and rigid structure of IR-FCD exhibits a robust intramolecular charge transfer capability, a lower band gap, enhanced photon absorption properties, and significant steric hindrance from vertically arranged alkyl chains to minimize non-radiative energy loss. By incorporating N-(but-3-yn-1-yl)-4-methylbenzenesulfonamide at the terminus of an elongated alkyl chain, followed by self-assembly into DSPE-S-S-PEG2000, NIR-II excitable phototheranostics (IR-FCD-Ts NPs) with endoplasmic reticulum (ER) targeting capability were successfully synthesized for imaging-guided photoimmunotherapy of TNBC. The IR-FCD-Ts NPs demonstrate exceptional optical characteristics, with maximum absorption at 1068 nm (extending to 1300 nm) and emission at 1273 nm (extending to 1700 nm), along with a high molar absorption coefficient of 2.76*104 L/mol·c at 1064 nm in aqueous solution. Under exposure to 1064 nm laser irradiation, IR-FCD-Ts NPs exhibit superior photothermal properties and have the potential for photodynamic therapy. By targeting ER, thereby inducing ER stress and significantly enhancing immunogenic cell death (ICD) in tumor cells, it triggers a strong antitumor immune response and inhibits the proliferation and metastasis of TNBC.

Lipid nanoparticles (LNP) are a safe and effective messenger RNA (mRNA) delivery system for vaccine applications, as shown by the COVID-19 mRNA vaccines. One of the main challenges faced during the development of these vaccines is the production of new and versatile LNP formulations capable of efficient encapsulation and delivery to cells in vivo. This study aimed to develop a new mRNA vaccine formulation that could potentially be used against existing diseases as well as those caused by pathogens that emerge every year.

Using firefly luciferase (Luc) as a reporter mRNA, we evaluated the physical-chemical properties, stability, and biodistribution of an LNP-mRNA formulation produced using a novel lipid composition and a microfluidic organic-aqueous precipitation method. Using mRNAs encoding a dengue virus or a Leishmania infantum antigen, we evaluated the immunogenicity of LNP-mRNA formulations and compared them with the immunization with the corresponding recombinant protein or plasmid-encoded antigens. For all tested LNP-mRNAs, mRNA encapsulation efficiency was higher than 85%, their diameter was around 100 nm, and their polydispersity index was less than 0.3. Following an intramuscular injection of 10 µg of the LNP-Luc formulation in mice, we detected luciferase activity in the injection site, as well as in the liver and spleen, as early as 6 h post-administration. LNPs containing mRNA encoding virus and parasite antigens were highly immunogenic, as shown by levels of antigen-specific IgG antibody as well as IFN-γ production by splenocytes of immunized animals that were similar to the levels that resulted from immunization with the corresponding recombinant protein or plasmid DNA.

Altogether, these results indicate that these novel LNP-mRNA formulations are highly immunogenic and may be used as novel vaccine candidates for different infectious diseases.

Non-alcoholic fatty liver disease (NAFLD) is a prevalent metabolic liver disorder worldwide, and effective therapeutic strategies for its treatment remains limited. In this article, we introduced Glipo-siRubi, a hepatocytes-targeting RNA interference (RNAi) nanoliposome for suppression of Rubicon expression, aiming to achieve precise regulation of autophagy in NAFLD. Autophagy activation induced by Rubicon suppression resulted in reduced endoplasmic reticulum stress and intracellular lipid accumulation in vitro. Moreover, Glipo-siRubi administration exhibited remarkable therapeutic efficacy, characterized by decreased liver lipid accumulation, ameliorated histopathology and improved insulin sensitivity in mice with western diet, indicating its notable potential against NAFLD. By inducing autophagy activation, the hepatocytes-targeting Glipo-siRubi provided a promising method for NAFLD treatment, addressing the limitations of current approaches. Our study highlighted the significance of Rubicon-specific suppression in NAFLD treatment, offering a specific, safe, and efficient approach to mitigate NAFLD.

Melanoma poses a significant threat to human health due to the lack of effective treatment options. Previous studies have demonstrated that the combination of photothermal therapy (PTT) and photodynamic therapy (PDT) can enhance therapeutic efficacy. However, conventional PTT/PDT combination strategies face various challenges, including complex preparation processes, potential damage to healthy tissues, and insufficient generation of reactive oxygen species (ROS). This study aims to design a rational and efficient PTT/PDT therapeutic strategy for melanoma and to explore its underlying mechanisms.

We first synthesized two target materials, indocyanine green-targeted liposomes (ICG-Lips) and magnetic microbubbles (MMBs), using the thin-film hydration method, followed by characterization and performance evaluation of both materials. Subsequently, we evaluated the synergistic therapeutic effects and underlying mechanisms of ICG-Lips combined with MMBs in melanoma treatment through in vitro experiments using cellular models and in vivo experiments using animal models.

Herein, we developed a multifunctional system comprising ICG-Lips and MMBs. ICG-Lips enhance targeted delivery through specific binding to the S100B protein on melanoma cells, while MMBs, via ultrasound (US)-induced cavitation effects, shorten the uptake time of ICG-Lips by melanoma cells and improve uptake efficiency. Furthermore, the combination of ICG-Lips and MMBs induces significant reactive oxygen species (ROS) generation. Under 808 nm laser irradiation, the accumulation of ICG-Lips in melanoma cells achieves mild photothermal therapy (mPTT) and PDT effects. The elevated temperature and excessive ROS generated during these processes result in glutathione (GSH) depletion, ultimately triggering ferroptosis. The occurrence of ferroptosis further amplifies PDT efficacy, creating a synergistic effect that effectively suppresses melanoma growth. Additionally, the combined therapeutic strategy of ICG-Lips and MMBs demonstrates excellent biosafety.

In summary, this study presents a novel and straightforward strategy that integrates mPTT, PDT, and ferroptosis synergistically to combat melanoma, thereby laying a solid foundation for improving melanoma treatment outcomes.

The vascular-disrupting agent DMXAA (5,6-dimethylxanthone-4-acetic acid) exhibits potent anticancer activity by targeting tumor vasculature and activating immune responses via the cGAS-STING pathway. However, its clinical application is hindered by nonspecific targeting and significant cardiovascular toxicity. This study introduces a novel self-amplified tumor-targeting delivery system(P@NPPD)comprising azide-functionalized poly(ethylene glycol)-b-poly-[(N-2-hydroxyethyl)-aspartamide]-DMXAA (N3-PEG-b-PHEA-DMXAA, NPPD) conjugated to DBCO modified platelets. Among them, NPPD was synthesized by conjugating DMXAA to N3-PEG-b-poly-[(N-2-hydroxyethyl)-aspartamide] through esterification. This system enhances tumor-specific drug delivery while minimizing systemic toxicity. Leveraging the natural tumor-homing properties of platelets and the coagulation cascade, P@NPPD selectively targets exposed collagen at tumor sites, initiating a self-amplifying release of DMXAA. This approach achieved a 2.61-fold improvement in targeting efficiency and an 89.1% tumor suppression rate. In addition to improving drug accumulation at tumor sites, P@NPPD significantly activated local immune responses, enhancing therapeutic efficacy and safety. These findings underscore the potential of P@NPPD as a promising platform for cancer therapy.

In recent years, mRNA vaccine has achieved increasing interest owing to its high potency, safety, ease of production, and low-cost manufacturing. Currently approved mRNA vaccines are administered intramuscularly to transfect local antigen-presenting cells (APCs) to initiate low to moderate immune responses. Spleen, the largest secondary lymphoid organ in the body which contains a large number of APCs close to B and T lymphocytes, could be the ideal site for effective initiation of an enhanced immune response. Here, we provide an overview of the recent advances in the development of synthetic materials for spleen-specific mRNA delivery, and lipid nanoparticle-based approaches will be highlighted. We further discuss the main challenges for spleen-specific mRNA delivery to provide a reference for the development of next-generation synthetic nanomaterials with optimal properties.

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.

Gold nanoparticles (GNPs) have gained significant attention as multifunctional agents in biomedical applications, particularly for enhancing radiotherapy. Their advantages, including low toxicity, high biocompatibility, and excellent conductivity, make them promising candidates for improving treatment outcomes across various radiation sources, such as femtosecond lasers, X-rays, Cs-137, and proton beams. However, a deeper understanding of their precise mechanisms in radiotherapy is essential for maximizing their therapeutic potential. This review explores the role of GNPs in enhancing reactive oxygen species (ROS) generation through plasmon-induced hot electrons or radiation-induced secondary electrons, leading to cellular damage in organelles such as mitochondria and the cytoskeleton. This additional pathway enhances radiotherapy efficacy, offering new therapeutic possibilities. Furthermore, we discuss emerging trends and future perspectives, highlighting innovative strategies for integrating GNPs into radiotherapy. This comprehensive review provides insights into the mechanisms, applications, and potential clinical impact of GNPs in cancer treatment.

Atherosclerosis is a chronic progressive disease which is known to cause acute cardiovascular events as well as cerebrovascular events with high mortality. Unlike many other diseases, atherosclerosis is often diagnosed only after an acute or fatal event. At present, the clinical problems of atherosclerosis mainly involve the difficulty in confirming the plaques or identifying the stability of the plaques in the early phase. In recent years, the development of nanotechnology has come with various advantages including non-invasive imaging enhancement, which can be studied for the imaging of atherosclerosis. For targeted imaging and atherosclerosis treatment, nanoliposomes provide enhanced stability, drug administration, extended circulation, and less toxicity. This review discusses the current advances in the development of tailored liposomal nano-radiopharmaceutical-based techniques and their applications to atherosclerotic plaque diagnosis. This review further highlights liposomal nano-radiopharmaceutical localisation and biodistribution-key processes in the pathophysiology of atherosclerosis. Finally, this review discusses the direction and future of liposomal nano-radiopharmaceuticals as a potential clinical tool for the assessment and diagnosis of atherosclerotic plaque.

DNA nanostructures (DNs) have gained popularity in various biomedical applications due to their unique properties, including structural programmability, ease of synthesis and functionalization, and low cytotoxicity. Effective utilization of DNs in biomedical applications requires a fundamental understanding of their interactions with living cells and the mechanics of cellular uptake. Current knowledge primarily focuses on how the physicochemical properties of DNs, such as mass, shape, size, and surface functionalization, affect uptake efficacy. However, the role of cellular mechanics and morphology in DN uptake remains largely unexplored. In this work, we show that cells subjected to geometric constraints remodel their actin cytoskeleton, resulting in differential mechanical force generation that facilitates DN uptake. The length, number, and orientation of F-actin fibers are influenced by these constraints, leading to distinct mechanophenotypes. Overall, DN uptake is governed by F-actin forces arising from filament reorganisation under geometric constraints. These results underscore the importance of actin dynamics in the cellular uptake of DNs and suggest that leveraging geometric constraints to induce specific cell morphology adaptations could enhance the uptake of therapeutically designed DNs.

Molecular recognition is of crucial importance in several healthcare applications, such as sensing, drug delivery, and therapeutics. Molecularly imprinted polymers (MIPs) present an interesting alternative to biological receptors (e.g., antibodies, enzymes) for this purpose since synthetic receptors overcome the limited robustness, flexibility, high-cost, and potential for inhibition that comes with natural recognition elements. However, off the shelf MIP products remain limited, which is likely due to the lack of a scalable production approach that can manufacture these materials in high yields and narrow and defined size distributions to have full control over their properties. In this Perspective, we will confer how breakthroughs in the automation of MIP design, manufacturing, and evaluation of performance will accelerate the (commercial) implementation of MIPs in healthcare technology. In addition, we will discuss how prediction of the in vivo behavior of MIPs with animal-free technologies (e.g., 3D tissue models) will be critical to assess their clinical potential.

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.

mRNA lipid nanoparticles (LNPs) are a powerful technology that are actively being investigated for their ability to prevent, treat, and study disease. However, a major limitation remains: achieving extrahepatic mRNA expression. The development of new carriers could enable the expression of mRNA in non-liver targets, thus expanding the utility of mRNA-based medicines. In this study, we use a combination of chemoinformatic-guided material synthesis and design of experiment optimization for the development of a spleen-expressing lipid nanoparticle (SE-LNP). We begin with the synthesis of a novel cholesterol derivative followed by SE-LNP formulation and design of experiment-guided optimization to identify three lead SE-LNPs. We then evaluate their in vitro delivery mechanism, in vivo biodistribution, and protein expression in mice, ultimately achieving spleen-preferential expression. The goal of this paper is thus to create LNPs that preferentially express mRNA in the spleen upon intravenous delivery, demonstrating the potential of LNPs to modulate gene expression in extrahepatic tissues for disease treatment.

Filamentous structures exert biological functions mediated by multivalent interactions with their counterparts in sharp contrast with spherical ones. The physicochemical properties and unique behaviors of nanofilaments that are associated with multivalent interaction with protein are poorly understood. Here, peptide-based nanofilaments containing different homotetrapeptidic inserts are reported and their protein adsorption and biological fates are tested. By altering the homotetrapeptides, different peptidic conformations are imposed within the nanofilaments, which result in notable differences in the density of the intermolecular hydrogen bond, determining the amount of adsorbed proteins. The adsorbed proteins can further induce interfilament entanglement of different degrees and patterns, which influences biodistribution and phagocytosis. The nanofilaments with tetrahydroxyproline segment exhibit diminish interfilament entanglement, phagocytosis, and improve circulation, biodistribution, and antitumor efficacy. These findings can deepen the understanding of nanofilament-protein interactions and filament-filament interactions as in the case of amyloid-β plaque, and facilitate the rational design of nanofilaments through peptide conformation control for chemical engineering and anticancer drug delivery.

Delivering protein drugs to the central nervous system (CNS) is challenging due to the blood-brain and blood-spinal cord barrier. Here we show that neutrophils, which naturally migrate through these barriers to inflamed CNS sites and release neutrophil extracellular traps (NETs), can be leveraged for therapeutic delivery. Tannic acid nanoparticles tethered with anti-Ly6G antibody and interferon-β (aLy6G-IFNβ@TLP) are constructed for targeted neutrophil delivery. These nanoparticles protect interferon-β from reactive oxygen species and preferentially accumulate in neutrophils over other immune cells. Upon encountering inflammation, neutrophils release the nanoparticles during NET formation. In the female mouse model of experimental autoimmune encephalomyelitis, intravenous administration of aLy6G-IFNβ@TLP reduce disease progression and restore motor function. Although this study focuses on IFNβ and autoimmune encephalomyelitis, the concept of hitchhiking neutrophils for CNS delivery and employing NET formation for inflamed site-specific nanoparticle release can be further applied for delivery of other protein drugs in the treatment of neurodegenerative diseases.

Extracellular vesicles (EVs) and extruded nanovesicles (ENVs) are promising nanovesicles (NVs) for drug delivery. However, the application of these NVs is strongly hindered by their short half-life in the circulation. Macrophages (Mφs) in the liver and spleen contribute to the rapid depletion of NVs, but the underlying mechanism is unclear.

By collecting the supernatant of PANC-1 cells and squeezing PANC-1 cells, EVs and ENVs derived from PANC-1 cells were prepared via ultracentrifugation. NVs were subsequently identified via western blot, particle size measurement, and electron microscopy. The distribution of NVs in mouse bodies was observed with a live animal imaging system. Liver Mφs were extracted and isolated after NVs were administered, and transcriptome profiling was applied to determine differentially expressed genes (DEGs). siRNAs targeting interested genes were designed and synthesized. In vitro experiments, Mφs were transfected with siRNA or treated with the corresponding inhibitor, after which NV uptake was recorded. Doxorubicin (DOX) was encapsulated in ENVs using an ultrasound method. PANC-1 cell-derived tumors were established in nude mice in vivo, inhibitor pretreatment or no treatment was administered before intravenous injection of ENVs-DOX, and the therapeutic efficacy of ENVs-DOX was evaluated.

NVs derived from PANC-1 cells were first prepared and identified. After intravenous injection, most NVs were engulfed by Mφs in the liver and spleen. Seven genes of interest were selected via transcriptome sequencing and validated via RT‒PCR. These results confirmed that the TLR2 signaling pathway is responsible for phagocytosis. siTLR2 and its inhibitor sparstolonin B (SpB) significantly inhibited the internalization of NVs by Mφs and downregulated the activity of the TLR2 pathway. The accumulation of ENVs-DOX in the liver was inhibited in vivo by pretreatment with SpB 40 min before intravenous injection, ultimately delaying tumor progression.

The TLR2 pathway plays a crucial role in the sequestration of NVs by Mφs. A novel antiphagocytic strategy in which pretreatment of mice with SpB inhibits the clearance of NVs and prolongs their half-life in vivo, thereby improving delivery efficiency, was identified.