Soft Mesoporous Organosilica Nanoplatforms Improve Blood Circulation, Tumor Accumulation/Penetration, and Photodynamic Efficacy

Nucleation-Inhibited Emulsion Interfacial Assembled Polydopamine Microvesicles as Artificial Antigen-Presenting Cells

Albeit microemulsion systems have emerged as efficient platforms for fabricating tunable nano/microstructures, lack of understanding on the emulsion-interfacial assembly hindered the control of fabrication. Herein, a nucleation-inhibited microemulsion interfacial assembly method is proposed, which deviates from conventional interfacial nucleation approaches, for the synthesis of polydopamine microvesicles (PDA MVs). These PDA MVs exhibit an approximate diameter of 1 µm, showcasing a pliable structure reminiscent of cellular morphology. Through modifications of antibodies on the surface of PDA MVs, their capacity as artificial antigen presentation cells is evaluated. In comparison to solid nanoparticles, PDA MVs with cell-like structures show enhanced T-cell activation, resulting in a 1.5-fold increase in CD25 expression after 1 day and a threefold surge in PD-1 positivity after 7 days. In summary, the research elucidates the influence of nucleation and interfacial assembly in microemulsion polymerization systems, providing a direct synthesis method for MVs and substantiating their effectiveness as artificial antigen-presenting cells.

Manganese-induced Photothermal-Ferroptosis for Synergistic Tumor Therapy

Ferroptosis-related tumor therapy based on nanomedicines has recently gained significant attention. However, the therapeutic performance is still hindered by the tumor's physical barriers such as the fibrotic tumor matrix and elevated interstitial fluid pressure, as well as chemical barriers like glutathione (GSH) overabundance. These physicochemical barriers impede the bioavailability of nanomedicines and compromise the therapeutic efficacy of lipid reactive oxygen species (ROS). Thus, this study pioneers a manganese-mediated overcoming of physicochemical barriers in the tumor microenvironment using organosilica-based nanomedicine (MMONs), which bolsters the synergy of photothermal-ferroptosis treatment. The MMONs display commendable proficiency in overcoming tumor physical barriers, due to their MnO2-mediated shape-morphing and softness-transformation ability, which facilitates augmented cellular internalization, enhanced tumor accumulation, and superior drug penetration. Also, the MMONs possess excellent capability in chemical barrier overcoming, including MnO2-mediated dual GSH clearance and enhanced ROS generation, which facilitates ferroptosis and heat shock protein inhibition. Notably, the resulting integration of physical and chemical barrier overcoming leads to amplified photothermal-ferroptosis synergistic tumor therapy both in vitro and in vivo. Accordingly, the comparative proteomic analysis has identified promoted ferroptosis with a transient inhibitory response observed in the mitochondria. This research aims to improve treatment strategies to better fight the complex defenses of tumors.

Cascade Nanoreactor Employs Mitochondrial-Directed Chemodynamic and δ-ALA-Mediated Photodynamic Synergy for Deep-Seated Oral Cancer Therapy

The management of oral squamous cell carcinoma (OSCC) poses significant challenges, leading to organ impairment and ineffective treatment of deep-seated tumors, adversely affecting patient prognosis. A cascade nanoreactor that integrates photodynamic therapy (PDT) and chemodynamic therapy (CDT) for comprehensive multimodal OSCC treatment is introduced. Utilizing iron oxide and mesoporous silica, the FMMSH drug delivery system, encapsulating the photosensitizer prodrug δ-aminolevulinic acid (δ-ALA), is developed. Triphenylphosphine (TPP) modification facilitates mitochondrial targeting, while tumor cell membrane (TCM) coating provides homotypic targeting. The dual-targeting δ-ALA@FMMSH-TPP-TCM demonstrate efficacy in eradicating both superficial and deep tumors through synergistic PDT/CDT. Esterase overexpression in OSCC cells triggers δ-ALA release, and excessive hydrogen peroxide in tumor mitochondria undergoes Fenton chemistry for CDT. The synergistic interaction of PDT and CDT increases cytotoxic ROS levels, intensifying oxidative stress and enhancing apoptotic mechanisms, ultimately leading to tumor cell death. PDT/CDT-induced apoptosis generates δ-ALA-containing apoptotic bodies, enhancing antitumor efficacy in deep tumor cells. The anatomical accessibility of oral cancer emphasizes the potential of intratumoral injection for precise and localized treatment delivery, ensuring focused therapeutic agent delivery to maximize efficacy while minimizing side effects. Thus, δ-ALA@FMMSH-TPP-TCM, tailored for intratumoral injection, emerges as a transformative modality in OSCC treatment.

Tumor microenvironment-responsive degradable silica nanoparticles: design principles and precision theranostic applications

Silica nanoparticles have emerged as promising candidates in the field of nanomedicine due to their remarkable versatility and customizable properties. However, concerns about their potential toxicity in healthy tissues and organs have hindered their widespread clinical translation. To address this challenge, significant attention has been directed toward a specific subset of silica nanoparticles, namely degradable silica nanoparticles, primarily because of their excellent biocompatibility and responsive biodegradability. In this review, we provide a comprehensive understanding of degradable silica nanoparticles, categorizing them into two distinct groups: inorganic species-doped and organic moiety-doped silica nanoparticles based on their framework components. Next, the recent progress of tumor microenvironment (TME)-responsive degradable silica nanoparticles for precision theranostic applications is summarized in detail. Finally, current bottlenecks and future opportunities of theranostic nanomedicines based on degradable silica nanoparticles in clinical applications are also outlined and discussed. The aim of this comprehensive review is to shed light on the potential of degradable silica nanoparticles in addressing current challenges in nanomedicine, offering insights into their design, applications in tumor diagnosis and treatment, and paving the way for future advancements in clinical theranostic nanomedicines.

Insights into tumor size-dependent nanoparticle accumulation using deformed organosilica nanoprobes

Deformed organosilica nanoprobes (CDPF) exhibit enhanced accumulation within larger tumors, highlighting the pivotal role of the tumor microenvironment in the optimization of nanoparticle-based therapeutic strategies.

Multimodal Imaging-Guided Photoimmunotherapy of Pancreatic Cancer by Organosilica Nanomedicine

Immune checkpoint blockade (ICB) treatments have contributed to substantial clinical progress. However, challenges persist, including inefficient drug delivery and penetration into deep tumor areas, inadequate response to ICB treatments, and potential risk of inflammation due to over-activation of immune cells and uncontrolled release of cytokines following immunotherapy. In response, this study, for the first time, presents a multimodal imaging-guided organosilica nanomedicine (DCCGP) for photoimmunotherapy of pancreatic cancer. The novel DCCGP nanoplatform integrates fluorescence, magnetic resonance, and real-time infrared photothermal imaging, thereby enhancing diagnostic precision and treatment efficacy for pancreatic cancer. In addition, the incorporated copper sulfide nanoparticles (CuS NPs) lead to improved tumor penetration and provide external regulation of immunotherapy via photothermal stimulation. The synergistic immunotherapy effect is realized through the photothermal behavior of CuS NPs, inducing immunogenic cell death and relieving the immunosuppressive tumor microenvironment. Coupling photothermal stimulation with αPD-L1-induced ICB, the platform amplifies the clearance efficiency of tumor cells, achieving an optimized synergistic photoimmunotherapy effect. This study offers a promising strategy for the clinical application of ICB-based combined immunotherapy and presents valuable insights for applications of organosilica in precise tumor immunotherapy and theranostics.

Nanoparticles with transformable physicochemical properties for overcoming biological barriers

In recent years, tremendous progress has been made in the development of nanomedicines for advanced therapeutics, yet their unsatisfactory targeting ability hinders the further application of nanomedicines. Nanomaterials undergo a series of processes, from intravenous injection to precise delivery at target sites. Each process faces different or even contradictory requirements for nanoparticles to pass through biological barriers. To overcome biological barriers, researchers have been developing nanomedicines with transformable physicochemical properties in recent years. Physicochemical transformability enables nanomedicines to responsively switch their physicochemical properties, including size, shape, surface charge, etc., thus enabling them to cross a series of biological barriers and achieve maximum delivery efficiency. In this review, we summarize recent developments in nanomedicines with transformable physicochemical properties. First, the biological dilemmas faced by nanomedicines are analyzed. Furthermore, the design and synthesis of nanomaterials with transformable physicochemical properties in terms of size, charge, and shape are summarized. Other switchable physicochemical parameters such as mobility, roughness and mechanical properties, which have been sought after most recently, are also discussed. Finally, the prospects and challenges for nanomedicines with transformable physicochemical properties are highlighted.

Stiffness-Transformable Nanoplatforms Responsive to the Tumor Microenvironment for Enhanced Tumor Therapeutic Efficacy

Herein, we report, for the first time, a unique stiffness-transformable manganese oxide hybridized mesoporous organosilica nanoplatform (MMON) for enhancing tumor therapeutic efficacy. The prepared MMONs had a quasi-spherical morphology and were completely transformed into soft bowl-like nanocapsules in the simulated tumor microenvironment through the breakage of Mn-O bonds, which decreased their Young's modulus from 165.7 to 84.5 MPa. Due to their unique stiffness transformation properties, the MMONs had reduced macrophage internalization, improved tumor cell uptake, and enhanced penetration of multicellular spheroids. In addition, in vivo experiments showed that the MMONs displayed a 3.79- and 2.90-fold decrease in non-specific liver distribution and a 2.87- and 1.83-fold increase in tumor accumulation compared to their soft and stiff counterparts, respectively. Furthermore, chlorin e6 (Ce6) modified MMONs had significantly improved photodynamic therapeutic effect.

Elasticity of mesoporous nanocapsules regulates cellular uptake, blood circulation, and intratumoral distribution

The elasticity of nanoparticles plays a critical role in regulating nanoparticle-biosystem interactions. However, the elasticity of traditional organic-based carriers can only be regulated within a narrow range, and the effects of elasticity on in vivo biological processes have not been evaluated until now. Here, we construct hyaluronic acid modified mesoporous organosilica nanoparticles (MONs-HA) with a wide range of elasticity by an interior preferential etching approach and investigate the impact of their elasticity on in vitro cellular uptake, in vivo blood circulation, and tumor accumulation. The Young's moduli of the prepared MONs-HA are 1.64, 0.93, 0.78, 0.4 and 0.29 GPa (denoted as rigid MONs₀-HA, semi-elastic MONs₂₀-HA and MONs₅₀-HA, elastic MONs₁₀₀-HA and MONs₂₀₀-HA), respectively. They all possess a similar hydrodynamic size (245-257 nm), similar surface electronegativity (-27 to -35 mV), and excellent dispersibility. In vitro experiments demonstrate that the elastic MONs₁₀₀-HA and MONs₂₀₀-HA (0.4 and 0.29 GPa) exhibit significantly greater cellular uptake relative to semi-elastic MONs₂₀-HA and MONs₅₀-HA (0.93 and 0.78 GPa) or rigid MONs₀-HA (1.64 GPa). Simultaneously, these elastic MONs₁₀₀-HA and MONs₂₀₀-HA show an efficiently prolonged circulation time. In vivo results revealed that the elastic MONs₁₀₀-HA show enhanced tumor accumulation compared to semi-elastic and rigid MONs-HA after intravenous administration. These desirable features of elasticity can direct the design of nanoplatforms, leading to an enhanced tumor delivery efficiency.

Flexible Hollow Human Serum Albumin-Catalase Nanocapsules with High Accumulation and Uptake Ability for Enhanced Photodynamic Therapy

Introduction

Photodynamic therapy (PDT) has attracted increasing attention for tumor treatment because of its minimal invasiveness and specific spatiotemporal selectivity. However, insufficient tumor accumulation and low cellular uptake of photosensitizers limit its therapeutic efficacy.

Methods

In this study, flexible hollow human serum albumin/catalase nanocapsules (HSA/CATs) were created using a core-assisted protein-coating method and combined with the photosensitizer chlorin e6 (HSA/CAT@Ce6) for PDT.

Results and Discussion

Transmission electron microscopy (TEM) images demonstrate that HSA/CAT nanocapsules are flexible, with a uniform diameter (310 nm) and a well-defined hollow structure. Thanks to their flexibility, HSA/CAT@Ce6 nanocapsules show a higher cellular uptake than rigid nanoparticles. The nanocapsules effectively generate reactive oxygen species (ROS) in 4T1 cells because of their high cellular uptake and catalytic capacity, remarkably enhancing their in vitro PDT efficacy. In addition, the in vivo tumor accumulation of HSA/CAT@Ce6 nanocapsules is significantly larger than that of rigid nanoparticles and Ce6, meaning they are highly effective in tumor cell ablation. This demonstrates that our flexible nanoplatform holds great promise for enhancing PDT of tumor.

miRNA-encapsulated abiotic materials and biovectors for cutaneous and oral wound healing: Biogenesis, mechanisms, and delivery nanocarriers

MicroRNAs (miRNAs) as therapeutic agents have attracted increasing interest in the past decade owing to their significant effectiveness in treating a wide array of ailments. These polymerases II-derived noncoding RNAs act through post-transcriptional controlling of different proteins and their allied pathways. Like other areas of medicine, researchers have utilized miRNAs for managing acute and chronic wounds. The increase in the number of patients suffering from either under-healing or over-healing wound demonstrates the limited efficacy of the current wound healing strategies and dictates the demands for simpler approaches with greater efficacy. Various miRNA can be designed to induce pathway beneficial for wound healing. However, the proper design of miRNA and its delivery system for wound healing applications are still challenging due to their limited stability and intracellular delivery. Therefore, new miRNAs are required to be identified and their delivery strategy needs to be optimized. In this review, we discuss the diverse roles of miRNAs in various stages of wound healing and provide an insight on the most recent findings in the nanotechnology and biomaterials field, which might offer opportunities for the development of new strategies for this chronic condition. We also highlight the advances in biomaterials and delivery systems, emphasizing their challenges and resolutions for miRNA-based wound healing. We further review various biovectors (e.g., adenovirus and lentivirus) and abiotic materials such as organic and inorganic nanomaterials, along with dendrimers and scaffolds, as the delivery systems for miRNA-based wound healing. Finally, challenges and opportunities for translation of miRNA-based strategies into clinical applications are discussed.

Elastic Nanovaccine Enhances Dendritic Cell-Mediated Tumor Immunotherapy

Nanovaccine-based immunotherapy (NBI) has the ability to initiate dendritic cell (DC)-mediated tumor-specific immune responses and maintain long-term antitumor immune memory. To date, the mechanism by which the mechanical properties of nanoparticles alter the functions of DCs in NBI remains largely unclear. Here, a soft mesoporous organosilica-based nanovaccine (SMONV) is prepared and the elasticity-dependent effect of the nanovaccine on the underlying DC-mediated immune responses is studied. It is found that the elasticity results in greater internalization of SMONV by DCs, followed by the induction of substantial cytosolic delivery of antigens via endosomal escape, leading to effective DC maturation and antigen cross-presentation. Impressively, elasticity enables SMONV to enhance lymphatic drainage of antigens in vivo, thus stimulating robust humoral and cellular immunity. The results from therapeutic tumor vaccination further reveal that subcutaneously administered SMONV effectively suppresses tumor growth in tumor-bearing mice by evoking antigen-specific CD8⁺ T-cell immune responses, mitigating regulatory T-cell-mediated immunosuppression, and increasing central memory and effector memory T-cell populations. Furthermore, combinatorial immunization with SMONV and anti-PD-L1 blocking antibodies results in an amplified therapeutic effect on tumor-bearing mice. These findings reveal the elastic effect of the nanovaccine on DC-mediated immune responses, and the prepared SMONV represents a facile and powerful strategy for antitumor immunotherapy.

Self-transformation synthesis of hierarchically porous benzene-bridged organosilica nanoparticles for efficient drug delivery

Herein, a feasible outside-in hydrothermal self-transformation strategy is presented to fabricate hierarchically porous benzene-bridged organosilica nanoparticles (HPBONs), and detailed mechanistic investigations were performed to study the formation of hierarchically porous nanostructures. The obtained HPBONs consisted of a mesoporous core (2.3 nm) and a large mesoporous flocculent shell (12.6 nm), which corresponded to an overall diameter of ∼ 200 nm and good water dispersibility, respectively. Owing to the unique hierarchically porous structure and high surface area (877 m²/g), HPBONs showed a high coloading capacity for the hydrophilic drug doxorubicin (DOX) and the hydrophobic photosensitizer chlorin e6 (Ce6) (355 µg/mg, 38 µg/mg, respectively) and acid-responsive DOX drug release (42.62%), leading to precise chemo-photodynamic therapy in vitro, as the cytotoxicity assay revealed 70% killing of breast cancer (MCF-7) cells. This research provides a new method to construct hierarchically porous organosilica-based nanodelivery systems.

Fluorescence resonance energy transfer monitoring of pH-responsive doxorubicin release from carbon dots/aptamer functionalized magnetic mesoporous silica

Aim: To develop a novel theranostic nanoplatform for simultaneous fluorescent monitoring and stimuli-triggered drug delivery. Materials & methods: Different microscopic and spectroscopic techniques were used for the characterization of nanocarriers. MCF-7 and human umbilical vein endothelial cell lines were cultured and treated with different doses of doxorubicin-loaded nanocarriers. The cell viability and drug release were studied using MTT assay and fluorescence microscopy. Results: Biocompatible and mono-disperse nanocarriers represent hollow and mesoporous structures with the calculated surface area of 552.83 m².g^-1, high magnetic activity (12.6 emu.g^-1), appropriate colloidal stability and high drug loading capacity (up to 61%). Conclusion: Taxane-based carbon dots act as the pH-responsive gatekeepers for the controlled release of doxorubicin into cancer cells and provide a fluorescence resonance energy transfer system for real-time monitoring of drug delivery.