Mesoporous organosilica nanoparticles: Degradation strategies and application in tumor therapy

Stimulus-Responsive Nano-Prodrug Strategies for Cancer Therapy: A Focus on Camptothecin Delivery

Camptothecin (CPT) is a highly cytotoxic molecule with excellent antitumor activity against various cancers. However, its clinical application is severely limited by poor water solubility, easy inactivation, and severe toxicity. Structural modifications and nanoformulations represent two crucial avenues for camptothecin's development. However, the potential for further structural modifications is limited, and camptothecin nanoparticles fabricated via physical loading have the drawbacks of low drug loading and leakage. Prodrug-based CPT nanoformulations have shown unique advantages, including increased drug loading, reduced burst release, improved bioavailability, and minimal toxic side effects. Stimulus-responsive CPT nano-prodrugs that respond to various endogenous or exogenous stimuli by introducing various activatable linkers to achieve spatiotemporally responsive drug release at the tumor site. This review comprehensively summarizes the latest research advances in stimulus-responsive CPT nano-prodrugs, including preparation strategies, responsive release mechanisms, and their applications in cancer therapy. Special focus is placed on the release mechanisms and characteristics of various stimulus-responsive CPT nano-prodrugs and their application in cancer treatment. Furthermore, clinical applications of CPT prodrugs are discussed. Finally, challenges and future research directions for CPT nano-prodrugs are discussed. This review to be valuable to readers engaged in prodrug research is expected.

Spatially Confined Nanoreactors Designed for Biological Applications

The applications of nanoreactors in biology are becoming increasingly significant and prominent. Specifically, nanoreactors with spatially confined, due to their exquisite design that effectively limits the spatial range of biomolecules, attracted widespread attention. The main advantage of this structure is designed to improve reaction selectivity and efficiency by accumulating reactants and catalysts within the chambers, thus increasing the frequency of collisions between reactants. Herein, the recent progress in the synthesis of spatially confined nanoreactors and their biological applications is summarized, covering various kinds of nanoreactors, including porous inorganic materials, porous crystalline materials with organic components and self-assembled polymers to construct nanoreactors. These design principles underscore how precise reaction control could be achieved by adjusting the structure and composition of the nanoreactors to create spatial confined. Furthermore, various applications of spatially confined nanoreactors are demonstrated in the biological fields, such as biocatalysis, molecular detection, drug delivery, and cancer therapy. These applications showcase the potential prospects of spatially confined nanoreactors, offering robust guidance for future research and innovation.

A Distinctive Insight into Inorganic Sonosensitizers: Design Principles and Application Domains

Sonodynamic therapy (SDT) as a promising non-invasive anti-tumor means features the preferable penetration depth, which nevertheless, usually can't work without sonosensitizers. Sonosensitizers produce reactive oxygen species (ROS) in the presence of ultrasound to directly kill tumor cells, and concurrently activate anti-tumor immunity especially after integration with tumor microenvironment (TME)-engineered nanobiotechnologies and combined therapy. Current sonosensitizers are classified into organic and inorganic ones, and current most reviews only cover organic sonosensitizers and highlighted their anti-tumor applications. However, there have few specific reviews that focus on inorganic sonosensitizers including their design principles, microenvironment regulation, etc. In this review, inorganic sonosensitizers are first classified according to their design rationales rather than composition, and the action rationales and underlying chemistry features are highlighted. Afterward, what and how TME is regulated based on the inorganic sonosensitizers-based SDT nanoplatform with an emphasis on the TME targets-engineered nanobiotechnologies are elucidated. Additionally, the combined therapy and their applications in non-cancer diseases are also outlined. Finally, the setbacks and challenges, and proposed the potential solutions and future directions is pointed out. This review provides a comprehensive and detailed horizon on inorganic sonosensitizers, and will arouse more attentions on SDT.

Organic-inorganic composite hydrogels: compositions, properties, and applications in regenerative medicine

Hydrogels, formed from crosslinked hydrophilic macromolecules, provide a three-dimensional microenvironment that mimics the extracellular matrix. They served as scaffold materials in regenerative medicine with an ever-growing demand. However, hydrogels composed of only organic components may not fully meet the performance and functionalization requirements for various tissue defects. Composite hydrogels, containing inorganic components, have attracted tremendous attention due to their unique compositions and properties. Rigid inorganic particles, rods, fibers, etc., can form organic-inorganic composite hydrogels through physical interaction and chemical bonding with polymer chains, which can not only adjust strength and modulus, but also act as carriers of bioactive components, enhancing the properties and biological functions of the composite hydrogels. Notably, incorporating environmental or stimulus-responsive inorganic particles imparts smartness to hydrogels, hence providing a flexible diagnostic platform for in vitro cell culture and in vivo tissue regeneration. In this review, we discuss and compare a set of materials currently used for developing organic-inorganic composite hydrogels, including the modification strategies for organic and inorganic components and their unique contributions to regenerative medicine. Specific emphasis is placed on the interactions between the organic or inorganic components and the biological functions introduced by the inorganic components. The advantages of these composite hydrogels indicate their potential to offer adaptable and intelligent therapeutic solutions for diverse tissue repair demands within the realm of regenerative medicine.

Silicon-containing nanomedicine and biomaterials: materials chemistry, multi-dimensional design, and biomedical application

The invention of silica-based bioactive glass in the late 1960s has sparked significant interest in exploring a wide range of silicon-containing biomaterials from the macroscale to the nanoscale. Over the past few decades, these biomaterials have been extensively explored for their potential in diverse biomedical applications, considering their remarkable bioactivity, excellent biocompatibility, facile surface functionalization, controllable synthesis, etc. However, to expedite the clinical translation and the unexpected utilization of silicon-composed nanomedicine and biomaterials, it is highly desirable to achieve a thorough comprehension of their characteristics and biological effects from an overall perspective. In this review, we provide a comprehensive discussion on the state-of-the-art progress of silicon-composed biomaterials, including their classification, characteristics, fabrication methods, and versatile biomedical applications. Additionally, we highlight the multi-dimensional design of both pure and hybrid silicon-composed nanomedicine and biomaterials and their intrinsic biological effects and interactions with biological systems. Their extensive biomedical applications span from drug delivery and bioimaging to therapeutic interventions and regenerative medicine, showcasing the significance of their rational design and fabrication to meet specific requirements and optimize their theranostic performance. Additionally, we offer insights into the future prospects and potential challenges regarding silicon-composed nanomedicine and biomaterials. By shedding light on these exciting research advances, we aspire to foster further progress in the biomedical field and drive the development of innovative silicon-composed nanomedicine and biomaterials with transformative applications in biomedicine.

Single-cell disulfidptosis regulator patterns guide intercellular communication of tumor microenvironment that contribute to kidney renal clear cell carcinoma progression and immunotherapy

Background

Disulfidptosis, an emerging type of programmed cell death, plays a pivotal role in various cancer types, notably impacting the progression of kidney renal clear cell carcinoma (KIRC) through the tumor microenvironment (TME). However, the specific involvement of disulfidptosis within the TME remains elusive.

Methods

Analyzing 41,784 single cells obtained from seven samples of KIRC through single-cell RNA sequencing (scRNA-seq), this study employed nonnegative matrix factorization (NMF) to assess 24 disulfidptosis regulators. Pseudotime analysis, intercellular communication mapping, determination of transcription factor activities (TFs), and metabolic profiling of the TME subgroup in KIRC were conducted using Monocle, CellChat, SCENIC, and scMetabolism. Additionally, public cohorts were utilized to predict prognosis and immune responses within the TME subgroup of KIRC.

Results

Through NMF clustering and differential expression marker genes, fibroblasts, macrophages, monocytes, T cells, and B cells were categorized into four to six distinct subgroups. Furthermore, this investigation revealed the correlation between disulfidptosis regulatory factors and the biological traits, as well as the pseudotime trajectories of TME subgroups. Notably, disulfidptosis-mediated TME subgroups (DSTN+CD4T-C1 and FLNA+CD4T-C2) demonstrated significant prognostic value and immune responses in patients with KIRC. Multiple immunohistochemistry (mIHC) assays identified marker expression within both cell clusters. Moreover, CellChat analysis unveiled diverse and extensive interactions between disulfidptosis-mediated TME subgroups and tumor epithelial cells, highlighting the TNFSF12-TNFRSF12A ligand-receptor pair as mediators between DSTN+CD4T-C1, FLNA+CD4T-C2, and epithelial cells.

Conclusion

Our study sheds light on the role of disulfidptosis-mediated intercellular communication in regulating the biological characteristics of the TME. These findings offer valuable insights for patients with KIRC, potentially guiding personalized immunotherapy approaches.

Current Advances on Nanomaterials Interfering with Lactate Metabolism for Tumor Therapy

Increasing numbers of studies have shown that tumor cells prefer fermentative glycolysis over oxidative phosphorylation to provide a vast amount of energy for fast proliferation even under oxygen-sufficient conditions. This metabolic alteration not only favors tumor cell progression and metastasis but also increases lactate accumulation in solid tumors. In addition to serving as a byproduct of glycolytic tumor cells, lactate also plays a central role in the construction of acidic and immunosuppressive tumor microenvironment, resulting in therapeutic tolerance. Recently, targeted drug delivery and inherent therapeutic properties of nanomaterials have attracted great attention, and research on modulating lactate metabolism based on nanomaterials to enhance antitumor therapy has exploded. In this review, the advanced tumor therapy strategies based on nanomaterials that interfere with lactate metabolism are discussed, including inhibiting lactate anabolism, promoting lactate catabolism, and disrupting the "lactate shuttle". Furthermore, recent advances in combining lactate metabolism modulation with other therapies, including chemotherapy, immunotherapy, photothermal therapy, and reactive oxygen species-related therapies, etc., which have achieved cooperatively enhanced therapeutic outcomes, are summarized. Finally, foreseeable challenges and prospective developments are also reviewed for the future development of this field.

Enhancing Cancer Chemo-Immunotherapy: Innovative Approaches for Overcoming Immunosuppression by Functional Nanomaterials

Chemotherapy is a critical modality in cancer therapy to combat malignant cell proliferation by directly attacking cancer cells and inducing immunogenic cell death, serving as a vital component of multi-modal treatment strategies for enhanced therapeutic outcomes. However, chemotherapy may inadvertently contribute to the immunosuppression of the tumor microenvironment (TME), inducing the suppression of antitumor immune responses, which can ultimately affect therapeutic efficacy. Chemo-immunotherapy, combining chemotherapy and immunotherapy in cancer treatment, has emerged as a ground-breaking approach to target and eliminate malignant tumors and revolutionize the treatment landscape, offering promising, durable responses for various malignancies. Notably, functional nanomaterials have substantially contributed to chemo-immunotherapy by co-delivering chemo-immunotherapeutic agents and modulating TME. In this review, recent advancements in chemo-immunotherapy are thus summarized to enhance treatment effectiveness, achieved by reversing the immunosuppressive TME (ITME) through the exploitation of immunotherapeutic drugs, or immunoregulatory nanomaterials. The effects of two-way immunomodulation and the causes of immunoaugmentation and suppression during chemotherapy are illustrated. The current strategies of chemo-immunotherapy to surmount the ITME and the functional materials to target and regulate the ITME are discussed and compared. The perspective on tumor immunosuppression reversal strategy is finally proposed.

Silica nanoparticles: A review of their safety and current strategies to overcome biological barriers

Silica nanoparticles (SNP) have gained tremendous attention in the recent decades. They have been used in many different biomedical fields including diagnosis, biosensing and drug delivery. Medical uses of SNP for anti-cancer, anti-microbial and theranostic applications are especially prominent due to their exceptional performance to deliver many different small molecules and recently biologics (mRNA, siRNA, antigens, antibodies, proteins, and peptides) at targeted sites. The physical and chemical properties of SNP such as large specific surface area, tuneable particle size and porosity, excellent biodegradability and biocompatibility make them an ideal drug delivery and diagnostic platform. Based on the available data and the pre-clinical performance of SNP, recent interest has driven these innovative materials towards clinical application with many of the formulations already in Phase I and Phase II trials. Herein, the progress of SNP in biomedical field is reviewed, and their safety aspects are analysed. Importantly, we critically evaluate the key structural characteristics of SNP to overcome different biological barriers including the blood-brain barrier (BBB), skin, tumour barrier and mucosal barrier. Future directions, potential pathways, and target areas towards rapid clinical translation of SNP are also recommended.

Sm/Co-Doped Silica-Based Nanozymes Reprogram Tumor Microenvironment for ATP-Inhibited Tumor Therapy

Current applications of multifunctional nanozymes for reprogramming the redox homeostasis of the tumor microenvironment (TME) have been severely confronted with low catalytic activity and the ambiguity of active sites of nanozymes, as well as the stress resistance from the rigorous physical environment of tumor cells. Herein, the Sm/Co-doped mesoporous silica with 3PO-loaded nanozymes (denoted as mSC-3PO) are rationally constructed for simultaneously inhibiting energy production by adenosine triphosphate (ATP) inhibitor 3PO and reprogramming TME by multiactivities of nanozymes with photothermal effect assist, i.e., enhanced peroxidase-like, catalase-like activity, and glutathione peroxidase-like activities, facilitating reactive oxygen species (ROS) generation, promoting oxygen content, and restraining the over-expressed glutathione. Through the optimal regulation of nanometric size and doping ratio, the fabricated superparamagnetic mSC-3PO enables the excellent exposure of active sites and avoids agglomeration owing to the large specific surface and mesoporous structure, thus providing adequate Sm/Co-doped active sites and enough spatial distribution. The constructed Sm/Co centers both participate in the simulated biological enzyme reactions and carry out the double-center catalytic process (Sm3+ and Co3+ /Co2+ ). Significantly, as the inhibitor of glycolysis, 3PO can reduce the ATP flow by cutting down the energy transform, thereby inhibiting tumor angiogenesis and assisting ROS to promote the early withering of tumor cells. In addition, the considerable near-infrared (NIR) light absorption of mSC-3PO can adapt to NIR excitable photothermal treatment therapy and photoexcitation-promoted enzymatic reactions. Taken together, this work presents a typical therapeutic paradigm of multifunctional nanozymes that simultaneously reprograms TME and promotes tumor cell apoptosis with photothermal assistance.

Dendritic Mesoporous Organosilica Nanoparticles with Photosensitizers for Cell Imaging, siRNA Delivery and Protein Loading

Dendritic mesoporous organosilica nanoparticles (DMON) are a new class of biodegradable nanoparticles suitable for biomolecule delivery. We studied the photochemical internalization (PCI) and photodynamic therapy (PDT) of DMON to investigate new ways for DMON to escape from the endosomes-lysosomes and deliver biomolecules into the cytoplasm of cells. We added photosensitizers in the framework of DMON and found that DMON were loaded with siRNA or FVIII factor protein. We made four formulations with four different photosensitizers. The photosensitizers allowed us to perform imaging of DMON in cancer cells, but the presence of the tetrasulfide bond in the framework of DMON quenched the formation of singlet oxygen. Fortunately, one formulation allowed us to efficiently deliver proapoptotic siRNA in MCF-7 cancer cells leading to 31% of cancer cell death, without irradiation. As for FVIII protein, it was loaded in two formulations with drug-loading capacities (DLC) up to 25%. In conclusion, DMON are versatile nanoparticles capable of loading siRNA and delivering it into cancer cells, and also loading FVIII protein with good DLC. Due to the presence of tetrasulfide, it was not possible to perform PDT or PCI.

Periodic Mesoporous Ionosilica Nanoparticles for BODIPY Delivery and Photochemical Internalization of siRNA

Periodic Mesoporous Ionosilica Nanoparticles (PMINPs) made via co-condensation reactions starting from an ionosilica precursor and a porphyrin derivative were used for simultaneous BODIPY/siRNA delivery in cancer cells. We observed high BODIPY loading capacities and efficiencies of the PMINPs that are triggered by anion exchange. siRNA adsorption took place on the surface of the nanoparticles, whereas BODIPY was encapsulated within the core of the nanoparticles. BODIPY release was found to be pH-dependent. Our results indicate 94 % BODIPY release after 16 h at pH 4, whereas only 2 % were released at pH 7.4. Furthermore, complexation with siRNA against luciferase gene was observed at the surface of PMINPs and gene silencing through its delivery via photochemical internalization (PCI) mechanism was efficient in MDA-MB-231 breast cancer cells expressing stable luciferase.

Microneedle-Assisted Transdermal Delivery of 2D Bimetallic Metal-Organic Framework Nanosheet-Based Cascade Biocatalysts for Enhanced Catalytic Therapy of Melanoma

Current conventional treatments for malignant melanoma still face limitations, especially low therapeutic efficacy and serious side effects, and more effective strategies are urgently needed to develop them. Delivering biocatalysts into tumors to efficiently trigger in situ cascade reactions has shown huge potential in producing more therapeutic species or generating stronger tumoricidal effects for augmented tumor therapy. Recently, ultrathin 2D metal-organic framework (MOF) nanosheets have acquired great interest in biocatalysis owing to their large surface areas and abundant accessible active catalytic sites. Herein, an enhanced catalytic therapeutic strategy against melanoma is developed by biocompatible microneedle (MN)-assisted transdermal delivery of a 2D bimetallic MOF nanosheet-based cascade biocatalyst (Cu-TCPP(Fe)@GOD). Profiting from the constructed dissolving MN system, the loaded Cu-TCPP(Fe)@GOD hybrid nanosheets can be accurately delivered into the melanoma sites through skin barriers, and subsequently, trigger the specific cascade catalytic reactions in response to the acidic tumor microenvironment to effectively generate highly toxic hydroxyl radical (^• OH) and deplete glucose nutrient for inducing the death of melanoma cells. The ultimate results prove the high melanoma inhibition effect and biosafety of such therapeutic modality, exhibiting a new and promising strategy to conquer malignant melanoma.

Modulation of hypoxia and redox in the solid tumor microenvironment with a catalytic nanoplatform to enhance combinational chemodynamic/sonodynamic therapy

The efficacy of reactive oxygen species-mediated therapy is generally limited by hypoxia and overexpressed glutathione (GSH) in the tumor microenvironment (TME). To address these issues, herein, a smart Mn₃O₄/OCN-PpIX@BSA nanoplatform is rationally developed to enhance the combinational therapeutic efficacy of chemodynamic therapy (CDT) and sonodynamic therapy (SDT) through TME modulation. For constructing the catalytic nanoplatform (Mn₃O₄/OCN-PpIX@BSA), Mn₃O₄ nanoparticles were grown in situ on oxidized g-C₃N₄ (OCN) nanosheets, and the as-prepared Mn₃O₄/OCN nano-hybrids were then successively loaded with protoporphyrin (PpIX) and coated with bovine serum albumin (BSA). The catalase-like Mn₃O₄ nanoparticles are able to effectively catalyze the overexpressed endogenous H₂O₂ to produce O₂, which could relieve hypoxia and improve the therapeutic effect of combinational CDT/SDT. The decomposition of Mn₃O₄ by GSH enables the release of Mn²⁺ ions, which not only facilitates good T₁/T₂ dual-modal magnetic resonance imaging for tumor localization but also results in the depletion of GSH and the Mn²⁺-driven Fenton-like reaction, thus further amplifying the oxidative stress and achieving improved therapeutic efficacy. It is worth noting that the Mn₃O₄/OCN-PpIX@BSA nanocomposites exhibit minimal toxicity to normal tissues at therapeutic doses. These positive findings provide a new strategy for the convenient construction of TME-regulating smart theranostic nanoagents to improve the therapeutic outcomes towards malignant tumors effectively.

Two-Dimensional FePS3 Nanosheets as an Integrative Sonosensitizer/Nanocatalyst for Efficient Nanodynamic Tumor Therapy

As the emerging modalities for tumor therapy, sonodynamic therapy (SDT) and chemodynamic therapy (CDT) can generate reactive oxygen species (ROS), typically inducing tumor cell apoptosis. However, the construction of more efficient sonosensitizers integrated with excellent Fenton/Fenton-like catalytic activity to improve the synergistic therapeutic effect of SDT and CDT is still highly challenging. In this study, 2D semiconductor FePS₃ nanosheets (NSs), as one of the metal phosphorus trichalcogenides for both sonosensitizer and Fenton catalyst, are successfully synthesized via an ultrasonic-assisted liquid phase exfoliation method from bulk FePS₃ and further modified with lipoic acid-polyethylene glycol (LA-PEG) to obtain FePS₃ -PEG NSs with desirable biocompatibility. The in vitro and in vivo results demonstrate that the engineered FePS₃ -PEG NSs induce the combinatorial SDT/CDT effect attributing to the enhanced ROS generation and significant glutathione depletion, which can conduct highly efficient and safe tumor inhibition and prolong the life span of tumor-bearing mice. This work provides the paradigm of semiconductor FePS₃ NSs as the integrative sonosensitizer/Fenton nanocatalyst for dual nanodynamic tumor therapy, paving the new way for exploring other 2D metal phosphorus trichalcogenides in biomedicine.

Tumor microenvironment enhanced NIR II fluorescence imaging for tumor precise surgery navigation via tetrasulfide mesoporous silica-coated Nd-based rare-earth nanocrystals

In vivo fluorescent imaging by using the new contrast agents emitted at short-wavelength infrared region (NIR II, 1000–1700 ​nm) presents an unprecedent advantages in imaging sensitivity and spatial resolution over traditional near-infrared (NIR) light. Recently, Nd-based rare-earth nanocrystals have attracted considerable attention due to the high quantum yield (∼40%) of their emission at NIR II. However, undesirable capture by reticuloendothelial system to bring strong background signal is unsatisfying for tumor discrimination. Here, GSH-sensitive tetrasulfide bond incorporated mesoporous silica shell has entrusted onto Nd-based down-conversion nanocrystals (DCNPs) surface to totally quench the fluorescence of DCNPs. After RGD conjugation on the silica surface, the NIR II contrast agents could actively target to liver tumors. Then tetrasulfide bonds can be broken during the silica framework decomposing in cytoplasm under high GSH concentration to result in NIR II fluorescence explosive recover. Benefiting from this specific response under tumor microenvironment, the NIR II signal in other organs was markedly reduced, while the signal-to-background ratio is prominently enhanced in tumors. Then, solid liver tumors were successfully resected under the guidance of our GSH responsive NIR II fluorescent imaging with no recurrence after 20-day of surgery. Meanwhile, by combining with the ignorable side effects, the Nd-based nanoprobes vastly improved the imaging resolution of tumor margin, opening a paradigm of NIR II fluorescent imaging-guided surgery.

Dendrimer-Modified Silica Nanoparticles for Efficient Enrichment of Low-Concentration Peptides

Peptide profiling based on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is of particular interest as it can provide physiologically and pathologically related information of the bio-samples. Due to the complexity of real biological samples, MALDI-TOF MS-based peptide mapping methods rely strongly on particular enrichment methods to improve the signal intensity. This paper introduces third-generation dendrimer-modified SBA-15 with the surface functionalization of amino and carboxyl group, respectively (denoted as SBA-15/G3-NH₂ and SBA-15/G3-COOH), for the efficient capture of low-abundance peptides. The enrichment ability of the nanocomposites was evaluated by standard peptides digests and real biological samples. The synthesized nanocomposites incorporated the benefit of dendrimers and mesoporous silica nanomaterial SBA-15, showing enhanced peptide enrichment ability. Therefore, this work may provide a new class of nanomaterials for peptide mapping from biological samples.

An Efficient Carbon-Based Drug Delivery System for Cancer Therapy through the Nucleus Targeting and Mitochondria Mediated Apoptotic Pathway

The emergence of nanocarriers solves the problems of antitumor drugs such as non-targeting, huge side effects, etc., and has been widely used in tumor therapy. Some kinds of antitumor drugs such as doxorubicin (DOX) mainly act on the nucleic acid causing DNA damage, interfering with transcription, and thereby disrupting or blocking the process of cancer cell replication. Herein, a new nanodrug delivery system, the carbon-based nanomaterials (CBNs)-Pluronic F127-DOX (CPD), is designed by using CBNs as a nanocarrier for DOX. As a result, the tumor growth inhibition rate of CPD group is as high as 79.42 ± 2.83%, and greatly reduces the side effects. The targeting rate of the CPD group of DOX in the tumor nucleus is 36.78%, and the %ID/g in tumor tissue is 30.09%. The CPD regulates the expression levels of Caspase-3, p53, and Bcl-2 genes by increasing intracellular reactive oxygen species (ROS) levels and reducing mitochondrial membrane potential, which indicates that mitochondrial-mediated pathways are involved in apoptosis. The CPD nanodrug delivery system increases the effective accumulation of DOX in tumor cell nuclei and tumor tissues, and generates massive ROS, thereby inhibiting tumor growth in vivo, representing a promising agent for anticancer applications.