Degradability and Clearance of Silicon, Organosilica, Silsesquioxane, Silica Mixed Oxide, and Mesoporous Silica Nanoparticles

Controlled release of antimicrobial peptides from nanocellulose wound dressings for treatment of wound infections

Wounds are highly prone to infection, which can delay healing and lead to severe complications such as gangrene and sepsis. Non-healing wounds significantly impact patients' physical and mental well-being and place a substantial financial burden on healthcare systems. Timely and effective treatment of wound infections is critical, but the rise of antibiotic-resistant pathogens complicates this process. In this study, we investigate a potent protease resistant antimicrobial peptide (AMP), PLNC8 αβ, for the treatment of wound infections and present a strategy for localized AMP delivery using functionalized advanced nanocellulose (NC) wound dressings. Two types of NC dressings were explored: bacterial cellulose (BC) and TEMPO-oxidized nanocellulose derived from wood powder (TC). In a porcine wound infection model, PLNC8 αβ exhibited high antimicrobial activity, successfully eradicating the infection while promoting wound re-epithelialization. To achieve controlled release of PLNC8 αβ from the NC dressings, the peptides were either physisorbed directly onto the nanofibrils or encapsulated within mesoporous silica nanoparticles (MSNs) that were incorporated into the dressings. The PLNC8 αβ functionalized dressings demonstrated low cytotoxicity toward human primary fibroblasts and keratinocytes. Both BC and TC dressings showed efficient contact inhibition of bacteria but were less effective in inhibiting bacteria in suspension. In contrast, MSN-functionalized dressings, displayed significantly enhanced peptide-loading and sustained release capacities, resulting in improved antimicrobial efficacy. These findings highlight the potential of PLNC8 αβ and PLNC8 αβ-functionalized nanocellulose wound dressings for the treatment of infected wounds, offering an effective alternative to conventional antibiotic therapies.

Thermo-responsive and biodegradable MoS2-based nanoplatform for tumor therapy and postoperative wound management

Inorganic nanoparticles serve as versatile nanoplatforms for efficient cancer diagnosis and therapy. However, their limited in vivo degradability and excretion rates may lead to various adverse effects. Furthermore, the cascade-controlled release of drugs remains a challenge. In this study, we developed a free-radical triggered degradable MoS2-AIPH@LA nanoplatform for tumor photothermal and oxygen-independent thermodynamic therapy. This was achieved by loading the free radical initiator (2,2'-azobis[2-(2-imidazolin-2-yl) propane] dihydrochloride (AIPH)) onto MoS2 nanoparticles and encapsulating them with thermo-responsive lauric acid (LA). Upon laser irradiation, the hyperthermia generated by MoS2 induces cancer cell death and releases AIPH, an oxygen-independent and thermal-responsive radical initiator capable of producing toxic alkyl free radicals for tumor therapy and inhibiting bacterial growth. Importantly, these free radicals promote the degradation rate of MoS2-AIPH@LA, further facilitating a rapid AIPH release and improving the biocompatibility of the MoS2-AIPH@LA nanoplatform. In particular, the thermo-responsive nature of LA in this formulation effectively regulates the release of AIPH, thus reducing potential AIPH leakage into the bloodstream and minimizing safety risks. With its free-radical-triggered degradation and cascade-controlled release capabilities, MoS2-AIPH@LA shows significant promise for inhibiting tumor proliferation and managing postoperative bacterial infection.

Supramolecular Porous Materials for Biomedical Applications

Supramolecular porous materials have been used to tackle some major challenges in modern biomedical science, including disease therapy and diagnosis. Their inherent dynamicity, stimuli-responsiveness, and tunable architectures enable precise control over molecular recognition, cargo encapsulation, and release kinetics. This perspective explores their potential in diagnostics and therapeutics, highlighting adaptability to physiological stimuli and precise control over structure via bottom-up assembly. A visionary framework is proposed for programmable self-assembly, where supramolecular building blocks form porous architectures with customized channels and responsive behavior, facilitating applications in tissue engineering, biosensing, soft robotics, and cargo recognition. Addressing challenges related to building block design, assembly conditions, and scalability will be crucial for translating these materials from bench to bedside. This perspective underscores the transformative potential of supramolecular porous materials in advancing personalized medicine and smart diagnostics.

Magnetic mesoporous silica nanoparticles as advanced polymeric scaffolds for efficient cancer chemotherapy: recent progress and challenges

Magnetic mesoporous silica nanoparticles (MMS NPs) stand out as excellent options for targeted chemotherapy owing to their remarkable features, such as extensive surface area, substantial pore volume, adjustable and uniform pore size, facile scalability, and versatile surface chemistry. This review comprehensively explores the latest developments in MMS NPs, emphasizing their design, functionalization, and application in cancer therapy. Initially, we discuss the critical need for targeted and controlled drug delivery (DD) in oncology, highlighting the role of magnetic and MMs in addressing some challenges. Subsequently, the key features of MMS NPs, such as their high surface area, pore structure, and functionalization strategies, are examined for their impact on their DD performance for efficient cancer chemotherapy. The integration of chemotherapy methods such as photothermal therapy and photodynamic therapy with MMS NPs is also explored, showcasing multifunctional platforms that combine imaging and therapeutic capabilities. Finally, we identify the current challenges and provide future perspectives for the development and clinical translation of MMS NPs, underscoring their potential to reshape CT paradigms.

Nanotechnology-Enhanced siRNA Delivery: Revolutionizing Cancer Therapy

RNA interference (RNAi) has emerged as a transformative approach for cancer therapy, enabling precise gene silencing through small interfering RNA (siRNA). However, the clinical application of siRNA-based treatments faces challenges such as rapid degradation, inefficient cellular uptake, and immune system clearance. Nanotechnology-enhanced siRNA delivery has revolutionized cancer therapy by addressing these limitations, improving siRNA stability, tumor-specific targeting, and therapeutic efficacy. Recent advancements in nanocarrier engineering have introduced innovative strategies to enhance the safety and precision of siRNA-based therapies, offering new opportunities for personalized medicine. This review highlights three key innovations in nanotechnology-enhanced siRNA delivery: artificial intelligence (AI)-driven nanocarrier design, multifunctional nanoparticles for combined therapeutic strategies, and biomimetic nanocarriers for enhanced biocompatibility. AI-driven nanocarriers utilize machine learning algorithms to optimize nanoparticle properties, improving drug release profiles and minimizing off-target effects. Multifunctional nanoparticles integrate siRNA with chemotherapy, immunotherapy, or photothermal therapy, enabling synergistic treatment approaches that enhance therapeutic outcomes and reduce drug resistance. Biomimetic nanocarriers, including exosome-mimicking systems and cell-membrane-coated nanoparticles, improve circulation time, immune evasion, and targeted tumor delivery. These innovations collectively enhance the precision, efficiency, and safety of siRNA-based cancer therapies. The scope and novelty of these advancements lie in their ability to overcome the primary barriers of siRNA delivery while paving the way for clinically viable solutions. This review provides a comprehensive analysis of the latest developments in nanocarrier fabrication, preclinical and clinical studies, and safety assessments. By integrating AI-driven design, multifunctionality, and biomimicry, nanotechnology-enhanced siRNA delivery holds immense potential for the future of precision cancer therapy.

The Toxicological Profile of Active Pharmaceutical Ingredients-Containing Nanoparticles: Classification, Mechanistic Pathways, and Health Implications

Nanotechnology is the manipulation of matter on an atomic and molecular scale, producing a lot of new substances with properties that are not necessarily easily expected based on present knowledge. Nanotechnology produces substances with unique properties that can be beneficial or harmful depending on their biocompatibility and distribution. Understanding nanomaterial toxicity is essential to ensure their safe application in biological and environmental applications. This review aims to provide a comprehensive overview of nanoparticle toxicity, focusing on their physicochemical properties, mechanisms of cellular uptake, and potential health risks. Key factors influencing toxicity include particle size, shape, concentration, aspect ratio, crystallinity, surface charge, dissolution, and agglomeration. Nanoparticles can induce oxidative stress and inflammation, contributing to adverse effects when inhaled, ingested, or applied to the skin. However, their toxicity may not be limited to just these pathways, as they can also exhibit other toxic properties, such as activation of the apoptotic pathway and mitochondrial damage. By summarizing the current knowledge on these aspects, this article intends to support the development of nanoparticles in a safer way for future applications.

A Critical View on the Biocompatibility of Silica Nanoparticles and Liposomes as Drug Delivery Systems

Silica-based materials and liposomes are widely employed in drug delivery systems, particularly as the most frequently evaluated platforms for intravenous drug administration. Their exceptional biocompatibility, versatile surface modification capabilities, and efficient encapsulation of a broad spectrum of therapeutic agents make them ideal for targeted and controlled drug delivery. Both nanodelivery systems interact with endothelial cells and various blood components, including erythrocytes (red blood cells) and white blood cells (lymphocytes, monocytes, and macrophages), potentially leading to cytotoxic effects. However, the detrimental impacts of silica nanoparticles (MSNs) and liposomes on healthy cells remain insufficiently investigated. The cytotoxicity of these carriers is strongly influenced by their physicochemical properties, such as size, surface charge, and functionalization, as well as the specific type of cells they encounter. This review aims to explore the molecular and cellular dysfunctions induced by MSNs and liposomes, which elicit various biological responses, including proinflammatory signaling, oxidative stress, and autophagy. Considering the toxicity associated with nanosilica and liposomes, strategies such as surface modifications and morphological adjustments may serve as effective approaches to mitigate these adverse effects. Implementing such modifications holds the potential to develop nanomaterials with lower toxicological profiles, thereby enhancing their safety and efficacy in clinical applications. By addressing these challenges, the advancement of silica-based materials and liposomes can be optimized for safer and more effective intravenous drug delivery systems.

Dual stimuli-responsive prodrug co-delivery nanosystem of salicylic acid and bioavailable silicon for long-term immunity in plant

Plant-induced resistance plays a crucial role in the plant defense system by activating intrinsic immune mechanisms. In this study, a novel amidase- and redox-responsive codelivery nanosystem was developed by covalently linking salicylic acid (SA) to functionalized disulfide-doped mesoporous silica nanoparticles (MSNs-ss-NH2) for the efficient delivery of SA and bioavailable silicon concurrently. Physicochemical characterization confirmed the successful preparation of MSNs-ss-SA, demonstrating its structural integrity and glutathione and amidase responsive degradation mechanism. With a particle size of approximately 90 nm, MSNs-ss-SA could penetrate the stomata of rice leaves, facilitating the efficient intracellular transport of SA and bioavailable silicon. Biological activity assays revealed that MSNs-ss-SA exhibited superior efficacy in inducing resistance to rice sheath blight compared to conventional SA, which was primarily due to its ability to enhance physical barrier formation, strengthen antioxidant defense systems, upregulate the expression of key defense-related genes, and increase chitinase synthesis, collectively triggering both systemic acquired resistance and induced systemic resistance. Most importantly, biological safety assessments confirmed its excellent compatibility with rice plants, aquatic organisms, soil ecosystems, and human cell models. Therefore, the prodrug system of SA and bioavailable silicon shows a significant potential for sustainable agricultural plant disease management.

Core-Shell Codelivery Nanocarrier Synergistically Regulates Cartilaginous Immune Microenvironment for Total Meniscus Replacement

Cartilage tissue engineering has made significant strides in clinical regenerative treatment. The success of cartilage regeneration critically depends on a favorable regenerative microenvironment by means of ideal bioactive scaffolds. However, total meniscus replacement frequently entails a harsh microenvironment of accompanying chronic inflammation and oxidative stress conditions after a massive injury, which extremely hinders tissue regenerative repair. Herein, a "core-shell" codelivery nanocarrier is developed to synergistically regulate the cartilaginous immune microenvironment (CIME) for total meniscus replacement. In this study, mesoporous silica nanoparticles are used to encapsulate an antioxidant and anti-inflammatory drug, Emodin, in the core and meanwhile modify a growth differentiation factor (GDF) by reversible disulfide bonds on the shell, together constructing a codelivery nanocarrier system (Em@MSN-GDF). The synergistic dual-drug release effectively reverses inflammation and oxidative microenvironment and is followed by successful promotion of fibrocartilage regeneration in vivo. Subsequently, Em@MSN-GDF-loaded cartilage-specific matrix hydrogels are combined with a meniscus-shaped polycaprolactone framework to construct a mechanically reinforced living meniscus substitute. As a result, rabbit experiments demonstrate that the codelivery nanocarrier system synergistically regulates the cartilaginous immune microenvironment, thereby achieving successful total meniscus replacement and fibrocartilage regeneration. The current study, therefore, offers a regenerative nanotreatment strategy to reverse the harsh microenvironment for total meniscus replacement.

Optimizing SiO2 Nanoparticle Structures to Enhance Drought Resistance in Tomato (Solanum lycopersicum L.): Insights into Nanoparticle Dissolution and Plant Stress Response

Drought stress significantly limits crop productivity and poses a critical threat to global food security. Silica nanoparticles (SiO2NPs) have shown a potential to mitigate drought stress, but the role of the nanostructure on overall efficacy remains unclear. This study evaluated solid (SSiO2NPs), porous (PSiO2NPs), and hollow (HSiO2NPs) SiO2NPs for their effects on drought-stressed tomatoes (Solanum lycopersicum L.). Silicic acid release rates followed the order: HSiO2NPs > PSiO2NPs > SSiO2NPs > Bulk-SiO2. Compared to untreated controls, foliar application of PSiO2NPs and HSiO2NPs under drought stress significantly improved shoot Si concentrations and plants' dry weight. These treatments also enhanced antioxidant enzyme activities (catalase, peroxidase, and superoxide dismutase) and phytohormone-targeted metabolome levels (jasmonic acid, salicylic acid, and auxin), contributing to greater drought tolerance. Conversely, SSiO2NPs, silicic acid, and Bulk-SiO2 had minimal impact on plant dry weight or physiological responses. These results highlight the importance of nanoparticles architecture in alleviating drought stress and promoting sustainable agriculture.

Variable pore size of mesoporous silica in improving physical stability and oral bioavailability of insoluble drugs

Mesoporous silica carriers are known to improve the solubility and bioavailability of poorly soluble Class II drugs. However, most mesoporous silica carriers available in the market have relatively low drug loading capacities. Therefore, it is essential to select the appropriate mesoporous silica carrier to control the particle size and form of poorly soluble drugs, as well as ensure efficient drug loading, particularly for drugs with large clinical dosages. In this study, three types of dendritic mesoporous silica nanoparticles (MSNs) with similar particle sizes but different pore sizes (25 nm, 15 nm, and 5 nm) were prepared, which could be degraded by 80 % in simulated intestinal fluid at pH 6.8 over 7 days. Fenofibrate (Fen) was loaded into MSNs, commercial mesoporous silica excipients, and a traditional solid dispersion excipient (PVP K-30) using the solvent evaporation method. MSNs showed a higher drug loading efficiency (about 33 %) compared to commercial excipients. The drug-loaded systems increased drug release rate and improved the hydrophilicity by reducing the contact angle. After loading, the specific surface area, pore volume, and pore size decreased. Under accelerated test condition, the rigid structure of MSNs prevented drug crystallization, avoiding the aging issues seen with traditional solid dispersions like PVP K-30, and improved the drug's long-term stability. Pharmacokinetic studies in rats showed that the bioavailability of self-made Fen capsules was 1.31 times higher than that of commercial capsules (Lipanthyl®). In summary, these results highlighted the potential of MSNs to improve the stability and oral absorption of poorly soluble drugs.

In Situ Slow-Release Hydrogen Sulfide Therapeutics for Advanced Disease Treatments

Hydrogen sulfide (H2S) gas therapygarners significant attention for its potential to improve outcomes in various disease treatments. The quantitative control of H2S release is crucial for effective the rapeutic interventions; however, traditional researchon H2S therapy frequently utilizes static release models and neglects the dynamic nature of blood flow. In this study, we propose a novel slow-release in-situ H2S release model that leverages the dynamic hydrolysis of H2S donorswithin the bloodstream. Calcium sulfide nanoparticles (CaS NPs) withmicrosolubility characteristics exhibit continuous H2S release, surpassing 24 h at normal blood flow velocities. The extended-release profile demonstrates superior potential in aligning with the bell-shapedpharmacological effect of H2S, compared to NaHS. Moreover, we synthesisedrare earth-doped CaS NPs (CaS: Eu2+, Sm3+ NPs) tha texhibit persistent luminescence, enabling visualisation of the continuous H2S release in trials. Our results demonstrate that lowdose CaS: Eu2+, Sm3+ NPs significantly reduces seizureduration to 1.2 ± 0.7 minutes, while high dose effectively suppresses colontumor growth with a tumor inhibition rate of 54%. Remarkably, these findings closely resemble endogenous H2S levels in treating epilepsy and tumors. This innovative slow-release, in-situ H2S the rapeutic approach via hydrolysis rejuvenates the development of H2S-basedtherapeutics.

Polysilsesquioxane Open Hollow Spheres for Heavy Metal Ions Adsorption

Hollow microspheres with open windows on the shells have shown significant potential in adsorption, catalysis, and drug delivery fields, owing to their low density, large interior volume, high specific surface area, and abundant availability of adsorption sites. However, creating open hollow spheres with structurally stable and entirely organic-functionalized surfaces remains a challenge. Herein, we fabricated polysilsesquioxane open hollow spheres using trialkoxysilane containing mercaptopropyl groups under vigorous stirring, employing polystyrene microspheres as a template. Various reaction parameters were explored, revealing stirring speed as the key factor influencing the morphology and openness of the microspheres. By examining the morphology of intermediate products at different reaction times, we proposed a step-growth mechanism for microsphere formation. The resulting materials exhibited high adsorption capacity and selectivity towards Hg2+ and Pb2+, attributed to the presence of thiol groups and the open-hollow structure. Our approach provides a robust method for producing open hollow materials with functionalized surfaces, offering potential applications in the adsorption field.

Green synthesized silicon dioxide nanoparticles (SiO2NPs) ameliorated the cadmium toxicity in melon by regulating antioxidant enzymes activity and stress-related genes expression

Green synthesized nanoparticles (NPs) are an eco-friendly and cost-effective approach to reduce heavy metal stress in plants. Among heavy metals, cadmium (Cd) possesses higher toxicity to the crops and ultimately reduces their growth and yield. The current study aims to evaluate the effectiveness of green synthesized SiO2NPs to reduce toxic effects of Cd in melon (Cucumis melo) by regulating physiological parameters, enhancing antioxidant enzyme activity, and modulating stress-related gene expression. The SiO2NPs were synthesized using Artemisia annua plant extract having spherical shape and size within the range of 40-70 nm and characterized using advanced spectroscopic and analytical techniques. The application of SiO2NPs (75 mg/L) significantly improved physiological parameters such as shoot length (SL), root length (RL), leaf fresh weight (LFW), root fresh weight (RFW), leaf dry weight (LDW) and root dry weight (RDW) by 14%, 20%, 15%, 16%, 14%, and 28%, respectively, compared to Cd-stressed plants. Photosynthetic pigments (chlorophyll and carotenoids) showed a notable increase of 15% and 40%, respectively. Furthermore, the activities of antioxidant enzymes such as SOD, POD, CAT, and APX were enhanced by 28.67%, 35.45%, 32.07%, and 42.75%, respectively. In addition, applying SiO2NPs increased the concentration of macronutrients N, P, and K by 33%, 40%, and 37%, respectively, compared to Cd-stressed plants. Moreover, SiO2NPs upregulated the expression of several stress-related genes and reduced Cd accumulation in shoots and roots. This study reveals that green synthesized SiO2NPs effectively reduced the Cd toxicity in melon by improving morphological and physiological parameters, enhancing antioxidant enzyme activity, and regulating the expression of stress-related genes. These findings suggest that green synthesized SiO2NPs could play a crucial role in sustainable agriculture by protecting crops from heavy metal stress.

Smart Mesoporous Silica Nanoparticles in Cancer: Diagnosis, Treatment, Immunogenicity, and Clinical Translation

In cancer research and personalized medicine, mesoporous silica nanoparticles (MSNs) have emerged as a significant breakthrough in both cancer treatment and diagnosis. MSNs offer targeted drug delivery, enhancing therapeutic effectiveness while minimizing adverse effects on healthy cells. Due to their unique characteristics, MSNs provide targeted drug delivery, maximizing therapeutic effectiveness with minimal adverse effects on healthy cells. The review thoroughly investigates the role of MSNs as potent drug carriers, noted for their high drug-loading capacity and controlled release, which significantly improves drug permeability and retention. Additionally, it discusses surface modification techniques that enable MSNs to target cancer cells precisely. The manuscript provides comprehensive insights into various MSN applications, including their role in cancer diagnosis, the design of advanced biosensors, and the development of both conventional and stimuli-responsive drug delivery platforms. Special focus is given to stimuli-triggered MSN systems, responsive to internal stimuli (e.g., pH, redox, enzyme) and external stimuli (e.g., temperature, magnetic field, light, ultrasound), highlighting the cutting-edge progress in MSN technology. Additionally, the review delves into the immunogenicity and biosafety aspects of MSNs, underscoring their potential for clinical translation. Besides summarizing the current state of MSN research in oncology, this review also illuminates the path for future advancements and clinical applications.

CRISPR/RNA Aptamer System Activated by an AND Logic Gate for Biomarker-Driven Theranostics

The development of an engineered RNA device capable of detecting multiple biomarkers to evaluate pathological states and autonomously implement responsive therapies is urgently needed. Here, we report InCasApt, an integrated nano CRISPR Cas13a/RNA aptamer theranostic platform capable of achieving both biomarker detection and biomarker-driven therapy. Within this system, a Cas13a/crRNA complex, a hairpin reporter (HR), a dinitroaniline caged Ce6 photosensitizer (Ce6-DN), and a DN-binding RNA aptamer precursor (DNBApt) are coloaded onto dendritic mesoporous silicon nanoparticles (DMSN) in a controlled manner. While InCasApt remains inert in normal cells, its programmable theranostic capabilities are activated in tumor cells that have elevated expression of carcinogenic miRNA-155 and miRNA-21. These miRNAs act as an AND logic gate, generating fluorescence for disease condition evaluation and ROS for photodynamic therapy. This process also upregulates antioncogene BRG1 and suppresses tumor migration by inhibiting the function of miRNA-155 and miRNA-21. These effects underscore the versatility of InCasApt as an miRNA-targeting strategy for bridging the gap between diagnosis and therapy.

Metabolomic characterization of MC3T3-E1pre-osteoblast differentiation induced by ipriflavone-loaded mesoporous nanospheres

This study reports on the metabolic changes accompanying the differentiation of MC3T3-E1 osteoprogenitor cells induced by mesoporous bioactive glass nanospheres (nMBG) loaded with ipriflavone (nMBG-IP). Ipriflavone (IP) is a synthetic isoflavone known for inhibiting bone resorption, maintaining bone density, and preventing osteoporosis. Delivering IP intracellularly is a promising strategy to modulate bone remodeling at significantly lower doses compared to free drug administration. Our results demonstrate that nMBG are efficiently internalized by pre-osteoblasts and, when loaded with IP, induce their differentiation. This differentiation process is accompanied by pronounced metabolic alterations, as monitored by NMR analysis of medium supernatants and cell extracts (exo- and endo-metabolomics, respectively). The main effects include an early-stage intensification of glycolysis and changes in several metabolic pathways, such as nucleobase metabolism, osmoregulatory and antioxidant pathways, and lipid metabolism. Notably, the metabolic impacts of nMBG-IP and free IP were very similar, whereas nMBG alone induced only mild changes in the intracellular metabolic profile without affecting the cells' consumption/secretion patterns or lipid composition. This finding indicates that the observed effects are primarily related to IP-induced differentiation and that nMBG nanospheres serve as convenient carriers with both efficient internalization and minimal metabolic impact. Furthermore, the observed link between pre-osteoblast differentiation and metabolism underscores the potential of utilizing metabolites and metabolic reprogramming as strategies to modulate the osteogenic process, for instance, in the context of osteoporosis and other bone diseases.

Dynamic light scattering unveils stochastic degradation in large-pore mesoporous silica nanoparticles

Mesoporous Silica Nanoparticles (MSNs) have been increasingly investigated as versatile drug delivery carriers. A particular challenge for the systemic use of MSNs lies in the control of their degradation, which has not been fully understood until now. We implemented standard dynamic light scattering (DLS) experiments and introduced a novel DLS technique in a confocal volume to track the dynamics of large-pore MSN degradation in situ. This unique DLS technique, which involves a small observation volume, was chosen for its ability to count particle by particle during the degradation process, a method that has not been commonly used in nanoparticle research. The experiments were performed in different media compositions at low particle concentrations, below the silica solubility limit. MSNs with large conical pores were prepared and studied as they offer the possibility to incorporate and release large-sized biomolecules. Large-pore MSNs followed a singular degradation mechanism following a stochastic-like behavior, a finding that challenges the common idea that all nanoparticles (NPs) degrade similarly and homogeneously over time. We showed that some NPs are observed intact over a prolonged period while most other NPs have already vanished or been transformed into swollen NPs. Thus, a heterogeneous degradation process occurs, while the total concentration of NPs undergoes an exponential decay. These large conical pores MSNs will be utilized as reliable biomolecule nanocarriers by predicting the factors underlying the NP hydrolytic stability.

Nanomaterial-Mediated Reprogramming of Macrophages to Inhibit Refractory Muscle Fibrosis

Orofacial muscles are particularly prone to refractory fibrosis after injury, leading to a negative effect on the patient's quality of life and limited therapeutic options. Gaining insights into innate inflammatory response-fibrogenesis homeostasis can aid in the development of new therapeutic strategies for muscle fibrosis. In this study, the crucial role of macrophages is identified in the regulation of orofacial muscle fibrogenesis after injury. Hypothesizing that orchestrating macrophage polarization and functions will be beneficial for fibrosis treatment, nanomaterials are engineered with polyethylenimine functionalization to regulate the macrophage phenotype by capturing negatively charged cell-free nucleic acids (cfNAs). This cationic nanomaterial reduces macrophage-related inflammation in vitr and demonstrates excellent efficacy in preventing orofacial muscle fibrosis in vivo. Single-cell RNA sequencing reveals that the cationic nanomaterial reduces the proportion of profibrotic Gal3+ macrophages through the cfNA-mediated TLR7/9-NF-κB signaling pathway, resulting in a shift in profibrotic fibro-adipogenic progenitors (FAPs) from the matrix-producing Fabp4+ subcluster to the matrix-degrading Igf1+ subcluster. The study highlights a strategy to target innate inflammatory response-fibrogenesis homeostasis and suggests that cationic nanomaterials can be exploited for treating refractory fibrosis.

Regenerative medicine: Hydrogels and mesoporous silica nanoparticles

Hydrogels, that are crosslinked polymer networks, can absorb huge quantities of water and/or biological fluids. Their physical properties, such as elasticity and soft tissue, together with their biocompatibility and biodegradability, closely resemble living tissues. The versatility of hydrogels has fuelled their application in various fields, such as agriculture, biomaterials, the food industry, drug delivery, tissue engineering, and regenerative medicine. Their combination with nanoparticles, specifically with Mesoporous Silica Nanoparticles (MSNs), have elevated these composites to the next level, since MSNs could improve the hydrogel mechanical properties, their ability to encapsulate and controlled release great amounts of different therapeutic agents, and their responsiveness to a variety of external and internal stimuli. In this review, the main features of both MSNs and hydrogels are introduced, followed by the discussion of different hydrogels-MSNs structures and an overview of their use in different applications, such as drug delivery technologies and tissue engineering.

Outbreak simulation on the neonatal ward using silica nanoparticles with encapsulated DNA: unmasking of key spread areas

BACKGROUND

Nosocomial infections pose a serious threat. In neonatal intensive care units (NICUs) especially, there are repeated outbreaks caused by micro-organisms without the sources or dynamics being conclusively determined.

AIM

To use amorphous silica nanoparticles with encapsulated DNA (SPED) to simulate outbreak events and to visualize dissemination patterns in a NICU to gain a better understanding of these dynamics.

METHODS

Three types of SPED were strategically placed on the ward to mimic three different dissemination dynamics among real-life conditions and employee activities. SPED DNA, resistant to disinfectants, was sampled at 22 predefined points across the ward for four days and quantitative polymerase chain reaction analysis was conducted.

FINDINGS

Starting from staff areas, a rapid ward-wide SPED dissemination including numerous patient rooms was demonstrated. In contrast, a primary deployment in a patient room only led to the spread in the staff area, with no distribution in the patient area.

CONCLUSION

This study pioneers SPED utilization in simulating outbreak dynamics. By unmasking staff areas as potential key trigger spots for ward-wide dissemination the revealed patterns could contribute to a more comprehensive view of outbreak events leading to rethinking of hygiene measures and training to reduce the rate of nosocomial infections in hospitals.

Optimized Fabrication of Dendritic Mesoporous Silica Nanoparticles as Efficient Delivery System for Cancer Immunotherapy

In the past decade, cancer immunotherapy has revolutionized the field of oncology. Major immunotherapy approaches such as immune checkpoint inhibitors, cancer vaccines, adoptive cell therapy, cytokines, and immunomodulators have shown great promise in preclinical and clinical settings. Among them, immunomodulatory agents including cancer vaccines are particularly appealing; however, they face limitations, notably the absence of efficient and precise targeted delivery of immune-modulatory agents to specific immune cells and the potential for off-target toxicity. Nanomaterials can play a pivotal role in addressing targeting and other challenges in cancer immunotherapy. Dendritic mesoporous silica nanoparticles (DMSNs) can enhance the efficacy of cancer vaccines by enhancing the effective loading of immune modulatory agents owing to their tunable pore sizes. In this work, an emulsion-based method is optimized to customize the pore size of DMSNs and loaded DMSNs with ovalbumin (OVA) and cytosine-phosphate-guanine (CpG) oligodeoxynucleotides (CpG-OVA-DMSNs). The immunotherapeutic effect of DMSNs is achieved through controlled chemical release of OVA and CpG in antigen-presenting cells (APCs). The results demonstrated that CpG-OVA-DMSNs efficiently activated the immune response in APCs and reduced tumor growth in the murine B16-OVA tumor model.

Engineering a Mesoporous Silicon Nanoparticle Cage to Enhance Performance of a Phosphotriesterase Enzyme for Degradation of VX Nerve Agent

The organophosphate (OP)-hydrolyzing enzyme phosphotriesterase (PTE, variant L7ep-3a) immobilized within a partially oxidized mesoporous silicon nanoparticle cage is synthesized and the catalytic performance of the enzyme@nanoparticle construct for hydrolysis of a simulant, dimethyl p-nitrophenyl phosphate (DMNP), and the live nerve agent VX is benchmarked against the free enzyme. In a neutral aqueous buffer, the optimized construct shows a ≈2-fold increase in the rate of DMNP turnover relative to the free enzyme. Enzyme@nanoparticles with more hydrophobic surface chemistry in the interior of the pores show lower catalytic activity, suggesting the importance of hydration of the pore interior on performance. The enzyme@nanoparticle construct is readily separated from the neutralized agent; the nanoparticle is found to retain DMNP hydrolysis activity through seven decontamination/recovery cycles. The nanoparticle cage stabilizes the enzyme against thermal denaturing and enzymatic (trypsin) degradation conditions relative to free enzyme. When incorporated into a topical gel formulation, the PTE-loaded nanoparticles show high activity toward the nerve agent VX in an ex vivo rabbit skin model. In vitro acetylcholinesterase (AChE) assays in human blood show that the enzyme@nanoparticle construct decontaminates VX, preserving the biological function of AChE when exposed to an otherwise incapacitating dose.

Investigation of a broad diversity of nanoparticles, including their processes, as well as toxicity testing in diverse organs and systems

Nanotechnology arising in wide-ranging areas, covers extensively different ranges of approaches attained from fields such as biology, chemistry, physics, and medicine engineering. Nanoparticles are a necessary part of nanotechnology effectually applied in the cure of a number of diseases. Nanoparticles have gained significant importance due to their unique properties, which differ from their bulk counterparts. These distinct properties of nanoparticles are primarily influenced by their morphology, size, and size distribution. At the nanoscale, nanoparticles exhibit behaviours that can enhance therapeutic efficacy and reduce drug toxicity. Their small size and large surface area make them promising candidates for applications such as targeted drug delivery, where they can improve treatment outcomes while minimizing adverse effects. The harmful effects of nanoparticles on the environment were critically investigated to obtain appropriate results and reduce the risk by incorporating the materials. Nanoparticles tend to penetrate the human body, clear the biological barriers to reach sensitive organs and are easily incorporated into human tissue, as well as dispersing to the hepatic tissues, heart tissues, encephalum, and GI tract. This study aims to examine a wide variety of nanoparticles, focusing on their manufacturing methods, functional characteristics, and interactions within biological systems. Particular attention will be directed towards assessing the toxicity of nanoparticles in different organs and physiological systems, yielding a thorough comprehension of their potential health hazards and the processes that drive nanoparticle-induced toxicity. This analysis will also emphasize recent developments in nanoparticle applications and safety assessment methodologies.

A Review of Current Developments in Functionalized Mesoporous Silica Nanoparticles: From Synthesis to Biosensing Applications

Functionalized mesoporous silica nanoparticles (MSNs) have been widely investigated in the fields of nanotechnology and material science, owing to their high surface area, diverse structure, controllable cavity, high biocompatibility, and ease of surface modification. In the past few years, great efforts have been devoted to preparing functionalized MSNs for biosensing applications with satisfactory performance. The functional structure and composition in the synthesis of MSNs play important roles in high biosensing performance. With the development of material science, diverse functional units have been rationally incorporated into mesoporous structures, which endow MSNs with design flexibility and multifunctionality. Here, an overview of the recent developments of MSNs as nanocarriers is provided, including the methodologies for the preparation of MSNs and the nanostructures and physicochemical properties of MSNs, as well as the latest trends of MSNs and their use in biosensing. Finally, the prospects and challenges of MSNs are presented.

Turn Hood into Good: Recycling Silicon from Mesoporous Silica Nanoparticles through Magnesium Modification to Lower Toxicity and Promote Tissue Regeneration

Mesoporous silica nanoparticles (MSNs) have gained wide application as excellent carrier materials; however, their limited degradation in the biological system and potential chronic toxicity pose challenges to their clinical applications. Previous studies have focused on optimizing the elimination performance of MSNs; interestingly, silicon has been well-documented as an essential body component. Therefore, converting MSNs into a form readily utilizable by the organism is a way to turn waste into a valuable resource. However, the recycling and utilization of MSNs are associated with significant hurdles. This study proposes an approach to impede the formation of siloxane, the crucial core in MSNs, by introducing a gradient concentration of Mg2+. The invasion of Mg2+ significantly reduces the stability of Si-O-Si bonds by substituting silicon ions while preserving the functional three-dimensional structure. Recycling the increased release of Mg and Si ions enhances cellular antioxidant capacity, reduces oxidative stress reactions, improves mitochondrial function, and regulates macrophage inflammatory states. The proposed approach to converting MSN materials shows significant advantages for tissue regeneration in the periodontal defect model. This study opens an insight for applying MSNs in clinical applications in regenerative medicine.

Recent Advances in Silica-Based Nanomaterials for Enhanced Tumor Imaging and Therapy

Cancer remains a formidable challenge, inflicting profound physical, psychological, and financial burdens on patients. In this context, silica-based nanomaterials have garnered significant attention for their potential in tumor imaging and therapy owing to their exceptional properties, such as biocompatibility, customizable porosity, and versatile functionalization capabilities. This review meticulously examines the latest advancements in the application of silica-based nanomaterials for tumor imaging and therapy. It underscores their potential in enhancing various cancer imaging modalities, including fluorescence imaging, magnetic resonance imaging, computed tomography, positron emission tomography, ultrasound imaging, and multimodal imaging approaches. Moreover, the review delves into their therapeutic efficacy in chemotherapy, radiotherapy, phototherapy, immunotherapy, gas therapy, sonodynamic therapy, chemodynamic therapy, starvation therapy, and gene therapy. Critical evaluations of the biosafety profiles and degradation pathways of these nanomaterials within biological environments are also presented. By discussing the current challenges and prospects, this review aims to provide a nuanced perspective on the clinical translation of silica-based nanomaterials, thereby highlighting their promise in revolutionizing cancer diagnostics, enabling real-time monitoring of therapeutic responses, and advancing personalized medicine.

Review and Future Perspectives of Stimuli-Responsive Bridged Polysilsesquioxanes in Controlled Release Applications

Bridged polysilsesquioxanes (BPSs) are emerging biomaterials composed of synergistic inorganic and organic components. These materials have been investigated as ideal carriers for therapeutic and diagnostic systems for their favorable properties, including excellent biocompatibility, physiological inertia, tunable size and morphology, and their extensive design flexibility of functional organic groups to satisfy diverse application requirements. Stimuli-responsive BPSs can be activated by both endogenous and exogenous stimuli, offering a precise, safe, and effective platform for the controlled release of various targeted therapeutics. This review aims to provide a comprehensive overview of stimuli-responsive BPSs, focusing on their synthetic strategies, biocompatibility, and biodegradability, while critically assessing their capabilities for controlled release in response to specific stimuli. Furthermore, practical suggestions and future perspectives for the design and development of BPSs are presented. This review highlights the significant role of stimuli-responsive BPSs in advancing biomedical research.

Hybrid Silica Cage-Type Nanostructures Made from Triply Hydrophilic Block Copolymers Single Micelles

Controlling the structure and functionality of porous silica nanoparticles has been a continuous source of innovation with important potential for advanced biomedical applications. Their synthesis, however, usually involves passive surfactants or amphiphilic copolymers that do not add value to the material after synthesis. In contrast, polyion complex (PIC) micelles based on hydrophilic block copolymers allow for the direct synthesis of intrinsically functional hybrid materials. While most previous studies have focused on bulk materials made from double-hydrophilic block copolymers (DHBC), in this work we have synthesized a triple-hydrophilic block copolymer (THBC) and demonstrated both its PIC micellization and its potential for hybrid mesoporous silica nanomaterials. Introducing this THBC has allowed to direct the transition from bulk three-dimensional (3D) materials to zero-dimensional (0D) nanomaterials with cage-type structures. The stabilization and isolation of these nanostructures formed around discrete individual micelles has been made possible by the careful design of the three different blocks that each play a key role. These nanostructures could also be synthesized from hybrid PIC micelles based on THBC-multivalent metal ions complexes, offering a direct route to metal/silica composite nanoparticles. This class of THBC polymers therefore creates significant opportunities for the synthesis of nanostructures with complex and functional architectures.

In situ modified mesoporous silica nanoparticles: synthesis, properties and theranostic applications

Over the last 20 years, mesoporous silica nanoparticles (MSNs) have drawn considerable attention in the biomedical field due to their large surface area, porous network, biocompatibility, and abundant modification possibilities. In situ MSN modification refers to the incorporation of materials such as alkoxysilanes, ions and nanoparticles (NPs) in the silica matrix during synthesis. Matrix modification is a popular approach for endowing MSNs with additional functionalities such as imaging properties, bioactivity, and degradability, while leaving the mesopores free for drug loading. As such, in situ modified MSNs are considered promising theranostic agents. This review provides an extensive overview of different materials and modification strategies that have been used and their effect on MSN properties. We also highlight how in situ modified MSNs have been applied in theranostic applications, oncology and regenerative medicine. We conclude with perspectives on the future outlooks and current challenges for the widespread clinical use of in situ modified MSNs.

A Mesoporous Silica-Loaded Multi-Functional Hydrogel Enhanced Tendon Healing via Immunomodulatory and Pro-Regenerative Effects

Tendon injuries are pervasive orthopedic injuries encountered by the general population. Nonetheless, recovery after severe injuries, such as Achilles tendon injury, is limited. Consequently, there is a pressing need to devise interventions, including biomaterials, that foster tendon healing. Regrettably, tissue engineering treatments have faced obstacles in crafting appropriate tissue scaffolds and efficacious nanomedical approaches. To surmount these hurdles, an innovative injectable hydrogel (CP@SiO2), comprising puerarin and chitosan through in situ self-assembly, is pioneered while concurrently delivering mesoporous silica nanoparticles for tendon healing. In this research, CP@SiO2 hydrogel is employed for the treatment of Achilles tendon injuries, conducting extensive in vivo and in vitro experiments to evaluate its efficacy. This reults demonstrates that CP@SiO2 hydrogel enhances the proliferation and differentiation of tendon-derived stem cells, and mitigates inflammation through the modulation of macrophage polarization. Furthermore, using histological and behavioral analyses, it is found that CP@SiO2 hydrogel can improve the histological and biomechanical properties of injured tendons. This findings indicate that this multifaceted injectable CP@SiO2 hydrogel constitutes a suitable bioactive material for tendon repair and presents a promising new strategy for the clinical management of tendon injuries.

ROS-responsive charge reversal mesoporous silica nanoparticles as promising drug delivery system for neovascular retinal diseases

Intravitreal injection of biodegradable implant drug carriers shows promise in reducing the injection frequency for neovascular retinal diseases. However, current intravitreal ocular devices have limitations in adjusting drug release rates for individual patients, thereby affecting treatment effectiveness. Accordingly, we developed mesoporous silica nanoparticles (MSNs) featuring a surface that reverse its charge in response to reactive oxygen species (ROS) for efficient delivery of humanin peptide (HN) to retinal epithelial cells (ARPE-19). The MSN core, designed with a pore size of 2.8 nm, ensures a high HN loading capacity 64.4% (w/w). We fine-tuned the external surface of the MSNs by incorporating 20% Acetyl-L-arginine (Ar) to create a partial positive charge, while 80% conjugated thioketal (TK) methoxy polyethylene glycol (mPEG) act as ROS gatekeeper. Ex vivo experiments using bovine eyes revealed the immobilization of Ar-MSNs-TK-PEG (mean zeta potential: 2 mV) in the negatively charged vitreous. However, oxidative stress reversed the surface charge to -25 mV by mPEG loss, facilitating the diffusion of the nanoparticles impeded with HN. In vitro studies showed that ARPE-19 cells effectively internalize HN-loaded Ar-MSNs-TK, subsequently releasing the peptide, which offered protection against oxidative stress-induced apoptosis, as evidenced by reduced TUNEL and caspase3 activation. The inhibition of retinal neovascularization was further validated in an in vivo oxygen-induced retinopathy (OIR) mouse model.

pH/glutathione-responsive theranostic nanoprobes for chemoimmunotherapy and magnetic resonance imaging of ovarian cancer cells

The integration of immunotherapy and standard chemotherapy holds great promise for enhanced anticancer effects. In this study, we prepared a pH- and glutathione (GSH)-sensitive manganese-doped mesoporous silicon (MMSNs) based drug delivery system by integrating paclitaxel (PTX) and anti-programmed cell death-ligand 1 antibody (aPD-L1), and encapsulating with polydopamine (PDA) for chemoimmunosynergic treatment of ovarian cancer cells. The nanosystem was degraded in response to the tumor weakly acidic and reductive microenvironment. The Mn2+ produced by degradation can be used as a contrast agent for magnetic resonance (MR) imaging to provide visual exposure to tumor tissue. The released PTX can not only kill tumor cells directly, but also induce immunogenic death (ICD) of tumor cells, which can play a synergistic therapeutic effect with aPD-L1. Therefore, our study is expected to provide a promising strategy for improving the efficacy of cancer immunotherapy and the detection rate of cancer.

Immunological properties of silica nanoparticles: a structure-activity relationship study

Silica nanoparticles are increasingly considered for drug delivery applications. These applications require an understanding of their biocompatibility, including their interactions with the immune system. However, systematic studies for silica nanoparticle immunological safety profiles are lacking. To fill this gap, we conducted an in vitro study investigating various aspects of silica nanoparticles' interactions with blood and immune cells. Four types of silica nanoparticles with variations in size and porosity were studied. These included nonporous Stöber silica nanoparticles with average diameters of approximately 50 and 100 nm (SNP50 and SNP100), mesoporous silica nanoparticles of approximately 100 nm (Meso100), and hollow mesoporous silica nanoparticles of approximately 100 nm (HMSNP100) in diameter, respectively. The hematological compatibility was assessed using hemolysis, complement activation, platelet aggregation, and plasma coagulation assays. The effects of nanoparticles on immune cell function were studied using in vitro phagocytosis, chemotaxis, natural killer cell cytotoxicity, leukocyte proliferation, human lymphocyte activation, colony-forming unit granulocyte-macrophage, and leukocyte procoagulant activity assays. The in vitro findings suggest that at high concentrations, corresponding to the in vivo human dose of 40 mg/kg, silica nanoparticles demonstrated an array of immunotoxic effects that depended on their physicochemical properties. However, all types of silica nanoparticles studied were not immunotoxic at concentrations corresponding to lower doses (≤ 8 mg/kg) comparable to that of nanocarriers in other nanomedicines currently used in the clinic. These findings are promising for using silica nanoparticles for the systemic delivery of bioactive and imaging agents.

Facile One Pot Synthesis of Hybrid Core-Shell Silica-Based Sensors for Live Imaging of Dissolved Oxygen and Hypoxia Mapping in 3D Cell Models

Fluorescence imaging allows for noninvasively visualizing and measuring key physiological parameters like pH and dissolved oxygen. In our work, we created two ratiometric fluorescent microsensors designed for accurately tracking dissolved oxygen levels in 3D cell cultures. We developed a simple and cost-effective method to produce hybrid core-shell silica microparticles that are biocompatible and versatile. These sensors incorporate oxygen-sensitive probes (Ru(dpp) or PtOEP) and reference dyes (RBITC or A647 NHS-Ester). SEM analysis confirmed the efficient loading and distribution of the sensing dye on the outer shell. Fluorimetric and CLSM tests demonstrated the sensors' reversibility and high sensitivity to oxygen, even when integrated into 3D scaffolds. Aging and bleaching experiments validated the stability of our hybrid core-shell silica microsensors for 3D monitoring. The Ru(dpp)-RBITC microparticles showed the most promising performance, especially in a pancreatic cancer model using alginate microgels. By employing computational segmentation, we generated 3D oxygen maps during live cell imaging, revealing oxygen gradients in the extracellular matrix and indicating a significant decrease in oxygen level characteristics of solid tumors. Notably, after 12 h, the oxygen concentration dropped to a hypoxic level of PO2 2.7 ± 0.1%.

Tailoring the pore structure of iron oxide core@stellate mesoporous silica shell nanocomposites: effects on MRI and magnetic hyperthermia properties and applicability to anti-cancer therapies

Core-shell nanocomposites made of iron oxide core (IO NPs) coated with mesoporous silica (MS) shells are promising theranostic agents. While the core is being used as an efficient heating nanoagent under alternating magnetic field (AMF) and near infra-red (NIR) light and as a suitable contrast agent for magnetic resonance imaging (MRI), the MS shell is particularly relevant to ensure colloidal stability in a biological buffer and to transport a variety of therapeutics. However, a major challenge with such inorganic nanostructures is the design of adjustable silica structures, especially with tunable large pores which would be useful, for instance, for the delivery of large therapeutic biomolecule loading and further sustained release. Furthermore, the effect of tailoring a porous silica structure on the magneto- or photothermal dissipation still remains poorly investigated. In this work, we undertake an in-depth investigation of the growth of stellate mesoporous silica (STMS) shells around IO NPs cores and of their micro/mesoporous features respectively through time-lapse and in situ liquid phase transmission electron microscopy (LPTEM) and detailed nitrogen isotherm adsorption studies. We found here that the STMS shell features (thickness, pore size, surface area) can be finely tuned by simply controlling the sol-gel reaction time, affording a novel range of IO@STMS core@shell NPs. Finally, regarding the responses under alternating magnetic fields and NIR light which are evaluated as a function of the silica structure, IO@STMS NPs having a tunable silica shell structure are shown to be efficient as T2-weighted MRI agents and as heating agents for magneto- and photoinduced hyperthermia. Furthermore, such IO@STMS are found to display anti-cancer effects in pancreatic cancer cells under magnetic fields (both alternating and rotating).

Temperature stability and enhanced transport properties by surface modifications of silica nanoparticle tracers for geo-reservoir exploration

Tracer tests are an important tool for characterizing and monitoring subsurface reservoir properties. However, they are limited both because of the tracer molecules constraining factors such as irreversible adsorption, retention, and degradations, i.e. interaction processes of fluorophore molecule with surrounding media resulting in a large variation in transport properties. Elaborate tests utilizing more than one tracer to distinguish time or location of injection are complex and interpretation is ambiguous because each tracer interacts differently. In this study, we present an approach to increase tracer stability and enhance the transport uniformity of different tracers, thus making tests utilizing multiple tracers simpler and more feasible. We present this concept of tracer multiplicity by encapsulating an anionic, cationic or amphoteric fluorophore inside mesoporous silica nanoparticle carriers coated with a protective titania layer. Upon encapsulation, increased thermal resistance and drastically lowered sorption affinity towards quartz sand was detected in batch and flow-through experiments. An additional advantage of the presented nanoparticle tracers over molecular tracers is their modularity, which is demonstrated by surface modifications and application of additives that greatly reduce sorption and increase recovery rates in the flow experiments. With the here presented concept of tracer multiplicity, we introduce a new approach for colloidal tracer design that has the potential to expand and enhance measurable parameters, measurement accuracy and simplicity of analysis.

Advancements in Nanoporous Materials for Biomedical Imaging and Diagnostics

This review explores the latest advancements in nanoporous materials and their applications in biomedical imaging and diagnostics. Nanoporous materials possess unique structural features, including high surface area, tunable pore size, and versatile surface chemistry, making them highly promising platforms for a range of biomedical applications. This review begins by providing an overview of the various types of nanoporous materials, including mesoporous silica nanoparticles, metal-organic frameworks, carbon-based materials, and nanoporous gold. The synthesis method for each material, their current research trends, and prospects are discussed in detail. Furthermore, this review delves into the functionalization and surface modification techniques employed to tailor nanoporous materials for specific biomedical imaging applications. This section covers chemical functionalization, bioconjugation strategies, and surface coating and encapsulation methods. Additionally, this review examines the diverse biomedical imaging techniques enabled by nanoporous materials, such as fluorescence imaging, magnetic resonance imaging (MRI), computed tomography (CT) imaging, ultrasound imaging, and multimodal imaging. The mechanisms underlying these imaging techniques, their diagnostic applications, and their efficacy in clinical settings are thoroughly explored. Through an extensive analysis of recent research findings and emerging trends, this review underscores the transformative potential of nanoporous materials in advancing biomedical imaging and diagnostics. The integration of interdisciplinary approaches, innovative synthesis techniques, and functionalization strategies offers promising avenues for the development of next-generation imaging agents and diagnostic tools with enhanced sensitivity, specificity, and biocompatibility.

Mesoporous Silica Nanoparticles as an Ideal Platform for Cancer Immunotherapy: Recent Advances and Future Directions

Cancer immunotherapy recently transforms the traditional approaches against various cancer malignancies. Immunotherapy includes systemic and local treatments to enhance immune responses against cancer and involves strategies such as immune checkpoints, cancer vaccines, immune modulatory agents, mimetic antigen-presenting cells, and adoptive cell therapy. Despite promising results, these approaches still suffer from several limitations including lack of precise delivery of immune-modulatory agents to the target cells and off-target toxicity, among others, that can be overcome using nanotechnology. Mesoporous silica nanoparticles (MSNs) are investigated to improve various aspects of cancer immunotherapy attributed to the advantageous structural features of this nanomaterial. MSNs can be engineered to alter their properties such as size, shape, porosity, surface functionality, and adjuvanticity. This review explores the immunological properties of MSNs and the use of MSNs as delivery vehicles for immune-adjuvants, vaccines, and mimetic antigen-presenting cells (APCs). The review also details the current strategies to remodel the tumor microenvironment to positively reciprocate toward the anti-tumor immune cells and the use of MSNs for immunotherapy in combination with other anti-tumor therapies including photodynamic/thermal therapies to enhance the therapeutic effect against cancer. Last, the present demands and future scenarios for the use of MSNs for cancer immunotherapy are discussed.

Custom-Design of Multi-Stimuli-Responsive Degradable Silica Nanoparticles for Advanced Cancer-Specific Chemotherapy

Chemotherapy is crucial in oncology for combating malignant tumors but often encounters obatacles such as severe adverse effects, drug resistance, and biocompatibility issues. The advantages of degradable silica nanoparticles in tumor diagnosis and treatment lie in their ability to target drug delivery, minimizing toxicity to normal tissues while enhancing therapeutic efficacy. Moreover, their responsiveness to both endogenous and exogenous stimuli opens up new possibilities for integrating multiple treatment modalities. This review scrutinizes the burgeoning utility of degradable silica nanoparticles in combination with chemotherapy and other treatment modalities. Commencing the elucidation of degradable silica synthesis and degradation mechanisms, emphasis is placed on the responsiveness of these materials to endogenous (e.g., pH, redox reactions, hypoxia, and enzymes) and exogenous stimuli (e.g., light and high-intensity focused ultrasound). Moreover, this exploration delves into strategies harnessing degradable silica nanoparticles in chemotherapy alone, coupled with radiotherapy, photothermal therapy, photodynamic therapy, gas therapy, immunotherapy, starvation therapy, and chemodynamic therapy, elucidating multimodal synergies. Concluding with an assessment of advances, challenges, and constraints in oncology, despite hurdles, future investigations are anticipated to augment the role of degradable silica in cancer therapy. These insights can serve as a compass for devising more efficacious combined tumor treatment strategies.

Polymeric functionalization of mesoporous silica nanoparticles: Biomedical insights

Mesoporous silica nanoparticles (MSNs) endowed with polymer coatings present a versatile platform, offering notable advantages such as targeted, pH-controlled, and stimuli-responsive drug delivery. Surface functionalization, particularly through amine and carboxyl modification, enhances their suitability for polymerization, thereby augmenting their versatility and applicability. This review delves into the diverse therapeutic realms benefiting from polymer-coated MSNs, including photodynamic therapy (PDT), photothermal therapy (PTT), chemotherapy, RNA delivery, wound healing, tissue engineering, food packaging, and neurodegenerative disorder treatment. The multifaceted potential of polymer-coated MSNs underscores their significance as a focal point for future research endeavors and clinical applications. A comprehensive analysis of various polymers and biopolymers, such as polydopamine, chitosan, polyethylene glycol, polycaprolactone, alginate, gelatin, albumin, and others, is conducted to elucidate their advantages, benefits, and utilization across biomedical disciplines. Furthermore, this review extends its scope beyond polymerization and biomedical applications to encompass topics such as surface functionalization, chemical modification of MSNs, recent patents in the MSN domain, and the toxicity associated with MSN polymerization. Additionally, a brief discourse on green polymers is also included in review, highlighting their potential for fostering a sustainable future.

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.

Porous silicon-based sensing and delivery platforms for wound management applications

Wound management remains a great challenge for clinicians due to the complex physiological process of wound healing. Porous silicon (PSi) with controlled pore morphology, abundant surface chemistry, unique photonic properties, good biocompatibility, easy biodegradation and potential bioactivity represent an exciting class of materials for various biomedical applications. In this review, we focus on the recent progress of PSi in the design of advanced sensing and delivery systems for wound management applications. Firstly, we comprehensively introduce the common type, normal healing process, delaying factors and therapeutic drugs of wound healing. Subsequently, the typical fabrication, functionalization and key characteristics of PSi have been summarized because they provide the basis for further use as biosensing and delivery materials in wound management. Depending on these properties, the rise of PSi materials is evidenced by the examples in literature in recent years, which has emphasized the robust potential of PSi for wound monitoring, treatment and theranostics. Finally, challenges and opportunities for the future development of PSi-based sensors and delivery systems for wound management applications are proposed and summarized. We hope that this review will help readers to better understand current achievements and future prospects on PSi-based sensing and delivery systems for advanced wound management.

Titania-mediated stabilization of fluorescent dye encapsulation in mesoporous silica nanoparticles

Mesoporous silica nanoparticles hosting guest molecules are a versatile tool with applications in various fields such as life and environmental sciences. Current commonly applied pore blocking strategies are not universally applicable and are often not robust enough to withstand harsh ambient conditions (e.g. geothermal). In this work, a titania layer is utilized as a robust pore blocker, with a test-case where it is used for the encapsulation of fluorescent dyes. The layer is formed by a hydrolysis process of a titania precursor in an adapted microemulsion system and demonstrates effective protection of both the dye payload and the silica core from disintegration under otherwise damaging external conditions. The produced dye-MSN@TiO2 particles are characterized by means of electron microscopy, elemental mapping, ζ-potential, X-ray diffraction (XRD), nitrogen adsorption, Thermogravimetric analysis (TGA), fluorescence and absorbance spectroscopy and Fourier Transform Infrared Spectroscopy - Total Attenuated Reflectance (FT-IR ATR). Finally, the performance of the titania-encapsulated MSNs is demonstrated in long-term aqueous stability and in flow-through experiments, where owing to improved dispersion encapsulated dye results in improved flow properties compared to free dye properties. This behavior exemplifies the potential advantage of carrier-borne marker molecules over free dye molecules in applications where accessibility or targeting are a factor, thus this encapsulation method increases the variety of fields of application.

Promotion of Th17 Polarized Immunity via Co-Delivery of Mincle Agonist and Tuberculosis Antigen Using Silica Nanoparticles

Adjuvants and immunomodulators that effectively drive a Th17-skewed immune response are not part of the standard vaccine toolkit. Vaccine adjuvants and delivery technologies that can induce Th17 or Th1/17 immunity and protection against bacterial pathogens, such as tuberculosis (TB), are urgently needed. Th17-polarized immune response can be induced using agonists that bind and activate C-type lectin receptors (CLRs) such as macrophage inducible C-type lectin (Mincle). A simple but effective strategy was developed for codelivering Mincle agonists with the recombinant Mycobacterium tuberculosis fusion antigen, M72, using tunable silica nanoparticles (SNP). Anionic bare SNP, hydrophobic phenyl-functionalized SNP (P-SNP), and cationic amine-functionalized SNP (A-SNP) of different sizes were coated with three synthetic Mincle agonists, UM-1024, UM-1052, and UM-1098, and evaluated for adjuvant activity in vitro and in vivo. The antigen and adjuvant were coadsorbed onto SNP via electrostatic and hydrophobic interactions, facilitating multivalent display and delivery to antigen presenting cells. The cationic A-SNP showed the highest coloading efficiency for the antigen and adjuvant. In addition, the UM-1098-adsorbed A-SNP formulation demonstrated slow-release kinetics in vitro, excellent stability over 12 months of storage, and strong IL-6 induction from human peripheral blood mononuclear cells. Co-adsorption of UM-1098 and M72 on A-SNP significantly improved antigen-specific humoral and Th17-polarized immune responses in vivo in BALB/c mice relative to the controls. Taken together, A-SNP is a promising platform for codelivery and proper presentation of adjuvants and antigens and provides the basis for their further development as a vaccine delivery platform for immunization against TB or other diseases for which Th17 immunity contributes to protection.

Strategies to Regulate the Degradation and Clearance of Mesoporous Silica Nanoparticles: A Review

Mesoporous silica nanoparticles (MSNs) have attracted extensive attention as drug delivery systems because of their unique meso-structural features (high specific surface area, large pore volume, and tunable pore structure), easily modified surface, high drug-loading capacity, and sustained-release profiles. However, the enduring and non-specific enrichment of MSNs in healthy tissues may lead to toxicity due to their slow degradability and hinder their clinical application. The emergence of degradable MSNs provided a solution to this problem. The understanding of strategies to regulate degradation and clearance of these MSNs for promoting clinical trials and expanding their biological applications is essential. Here, a diverse variety of degradable MSNs regarding considerations of physiochemical properties and doping strategies of degradation, the biodistribution of MSNs in vivo, internal clearance mechanism, and adjusting physical parameters of clearance are highlighted. Finally, an overview of these degradable and clearable MSNs strategies for biosafety is provided along with an outlook of the encountered challenges.

Upconverting Nanoparticles Coated with Light-Breakable Mesoporous Silica for NIR-Triggered Release of Hydrophobic Molecules

Upconverting nanoparticles (UCNPs) doped with Yb3+ and Tm3+ are near-infrared (NIR) to ultraviolet (UV) transducers that can be used for NIR-controlled drug delivery. However, due to the low quantum yield of upconversion, high laser powers and long irradiation times are required to trigger this drug release. In this work, we report the one-step synthesis of a nanocomposite consisting of a LiYbF4:Tm3+@LiYF4 UCNP coated with mesoporous UV-breakable organosilica shells of various thicknesses. We demonstrate that a thin shell accelerates the breakage of the shell at 1 W/cm2 NIR light exposure, a laser power up to 9 times lower than that of conventional systems. When the mesopores are loaded with hydrophobic vitamin D3 precursor 7-dehydrocholesterol (7-DH), shell breakage results in subsequent cargo release. Its minimal toxicity in HeLa cells and successful internalization into the cell cytoplasm demonstrate its biocompatibility and potential application in biological systems. The tunability of this system due to its simple, one-step synthesis process and its ability to operate at low laser powers opens up avenues in UCNP-powered NIR-triggered drug delivery toward a more scalable, flexible, and ultimately translational option.

Magnetically modified-mitoxantrone mesoporous organosilica drugs: an emergent multimodal nanochemotherapy for breast cancer

BACKGROUND

Chemotherapy, the mainstay treatment for metastatic cancer, presents serious side effects due to off-target exposure. In addition to the negative impact on patients' quality of life, side effects limit the dose that can be administered and thus the efficacy of the drug. Encapsulation of chemotherapeutic drugs in nanocarriers is a promising strategy to mitigate these issues. However, avoiding premature drug release from the nanocarriers and selectively targeting the tumour remains a challenge.

RESULTS

In this study, we present a pioneering method for drug integration into nanoparticles known as mesoporous organosilica drugs (MODs), a distinctive variant of periodic mesoporous organosilica nanoparticles (PMOs) in which the drug is an inherent component of the silica nanoparticle structure. This groundbreaking approach involves the chemical modification of drugs to produce bis-organosilane prodrugs, which act as silica precursors for MOD synthesis. Mitoxantrone (MTO), a drug used to treat metastatic breast cancer, was selected for the development of MTO@MOD nanomedicines, which demonstrated a significant reduction in breast cancer cell viability. Several MODs with different amounts of MTO were synthesised and found to be efficient nanoplatforms for the sustained delivery of MTO after biodegradation. In addition, Fe3O4 NPs were incorporated into the MODs to generate magnetic MODs to actively target the tumour and further enhance drug efficacy. Importantly, magnetic MTO@MODs underwent a Fenton reaction, which increased cancer cell death twofold compared to non-magnetic MODs.

CONCLUSIONS

A new PMO-based material, MOD nanomedicines, was synthesised using the chemotherapeutic drug MTO as a silica precursor. MTO@MOD nanomedicines demonstrated their efficacy in significantly reducing the viability of breast cancer cells. In addition, we incorporated Fe3O4 into MODs to generate magnetic MODs for active tumour targeting and enhanced drug efficacy by ROS generation. These findings pave the way for the designing of silica-based multitherapeutic nanomedicines for cancer treatment with improved drug delivery, reduced side effects and enhanced efficacy.

Customized Lanthanide Nanobiohybrids for Noninvasive Precise Phototheranostics of Pulmonary Biofilm Infection

A noninvasive strategy for in situ diagnosis and precise treatment of bacterial biofilm infections is highly anticipated but still a great challenge. Currently, no in vivo biofilm-targeted theranostic agent is available. Herein, we fabricated intelligent theranostic alginate lyase (Aly)-NaNdF4 nanohybrids with a 220 nm sunflower-like structure (NaNdF4@DMS-Aly) through an enrichment-encapsulating strategy, which exhibited excellent photothermal conversion efficiency and the second near-infrared (NIR-II) luminescence. Benefiting from the site-specific targeting and biofilm-responsive Aly release from NaNdF4@DMS-Aly, we not only enabled noninvasive diagnosis but also realized Aly-photothermal synergistic therapy and real-time evaluation of therapeutic effect in mice models with Pseudomonas aeruginosa biofilm-induced pulmonary infection. Furthermore, such nanobiohybrids with a sheddable siliceous shell are capable of delaying the NaNdF4 dissolution and biodegradation upon accomplishing the therapy, which is highly beneficial for the biosafety of theranostic agents.