Precision Cancer Theranostic Platform by In Situ Polymerization in Perylene Diimide-Hybridized Hollow Mesoporous Organosilica Nanoparticles

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.

Photoactivated Formation of an Extravascular Dynamic Hydrogel as an Intelligent Blood Flow Regulator to Reprogram the Immunogenic Landscape

Long-term tumor starvation may be a potential strategy to elevate the antitumor immune response by depriving nutrients. However, combining long-term starvation therapy with immunotherapy often yields limited efficacy due to the blockage of immune cell migration pathways. Herein, an intelligent blood flow regulator (BFR) is first established through photoactivated in situ formation of the extravascular dynamic hydrogel to compress blood vessels, which can induce long-term tumor starvation to elicit metabolic stress in tumor cells without affecting immune cell migration pathways. By leveraging methacrylate-modified nanophotosensitizers (HMMAN) and biodegradable gelatin methacrylate (GelMA), the developed extravascular hydrogel dynamically regulates blood flow via enzymatic degradation. Additionally, aPD-L1 loaded into HMMAN continuously blocks immune checkpoints. Systematic in vivo experiments demonstrate that the combination of immune checkpoint blockade (ICB) and BFR-induced metabolic stress (BIMS) significantly delays the progression of Lewis lung and breast cancers by reshaping the tumor immunogenic landscape and enhancing antitumor immune responses.

Toward Type I/II ROS Generation Photoimmunotherapy by Molecular Engineering of Semiconducting Perylene Diimide

As prospective phototheranostic agents for cancer imaging and therapy, semiconducting organic molecule-based nanomedicines are developed. However, near-infrared (NIR) emission, and tunable type I (O2 • -) and type II (1O2) photoinduced reactive oxygen species (ROS) generation to boost cancer photoimmunotherapy remains a big challenge. Herein, a series of D-π-A structures, NIR absorbing perylene diimides (PDIs) with heavy atom bromide modification at the bay position of PDIs are prepared for investigating the optimal photoinduced type I/II ROS generation. The heavy atom effect has demonstrated a reduction of molecular ∆EST and promotion of the intersystem crossing processes of PDIs, enhancing the photodynamic therapy (PDT) efficacy. The modification of three bromides and one pyrrolidine at the bay position of PDI (TBDT) has demonstrated the best type I/II PDT performance by batch experiments and theoretical calculations. TBDT based nanoplatforms (TBDT NPs) enable type I/II PDT in the hypoxic tumor microenvironment as a strong immunogenic cell death (ICD) inducer. Moreover, TBDT NPs showing NIR emission allow in vivo bioimaging guided phototherapy of tumor. This work uses novel PDIs with adjustable type I/II ROS production to promote antitumor immune response and accomplish effective tumor eradication, consequently offering molecular guidelines for building high-efficiency ICD inducers.

Photoactivation Inducing Multifunctional Coupling of Fluorophore for Efficient Tumor Therapy In Situ

Photoactivatable molecules, with high-precision spatialtemporal control, have largely promoted bioimaging and phototherapy applications of fluorescent dyes. Here, the first photoactivatable sensor (BI) is described that can be triggered by broad excitation light (405-660 nm), which further undergoes intersystem crossing and H-atom transfer processes to forming superoxide anion radicals (O2 -• ) and carbon radicals. Particularly, the photoinduced gain of carbon-centered radicals (BI•) allows for radical-radical coupling to afford the combined crosslink product (BI─BI), which would be oxidized in the presence of O2 -• to produce an extended conjugate system with near infrared emission (820 nm). Besides, the photochemically generated product (Cy─BI) possesses ultra-high photothermal conversion efficiency up to 90.9%, which optimized phototherapy potential. What's more, Western Blot assay reveals that both BI and the photoproduct Cy─BI can efficiently inhibit the expression of CHK1, and the irradiation of BI and Cy─BI further induces apoptosis and ultimately enhances the phototherapeutic effects. Thus, the combination of cell cycle block inducing apoptosis, photodynamic therapy and photothermal therapy treatments significantly suppress solid tumor in vivo antitumor efficacy explorations. This is a novel finding in developing photoactivatable molecules, as well as the broad applicability of photoimaging and phototherapy in tumor-related areas.

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.

Reshaping Intratumoral Mononuclear Phagocytes with Antibody-Opsonized Immunometabolic Nanoparticles

Mononuclear phagocytes (MPs) are vital components of host immune defenses against cancer. However, tumor-infiltrating MPs often present tolerogenic and pro-tumorigenic phenotypes via metabolic switching triggered by excessive lipid accumulation in solid tumors. Inspired by viral infection-mediated MP modulation, here enveloped immunometabolic nanoparticles (immeNPs) are designed to co-deliver a viral RNA analog and a fatty acid oxidation regulator for synergistic reshaping of intratumoral MPs. These immeNPs are camouflaged with cancer cell membranes for tumor homing and opsonized with anti-CD163 antibodies for specific MP recognition and uptake. It is found that internalized immeNPs coordinate lipid metabolic reprogramming with innate immune stimulation, inducing M2-to-M1 macrophage repolarization and tolerogenic-to-immunogenic dendritic cell differentiation for cytotoxic T cell infiltration. The authors further demonstrate that the use of immeNPs confers susceptibility to anti-PD-1 therapy in immune checkpoint blockade-resistant breast and ovarian tumors, and thereby provide a promising strategy to expand the potential of conventional immunotherapy.

Recent Research Advances in Nano-Based Drug Delivery Systems for Local Anesthetics

From a clinical perspective, local anesthetics have rather widespread application in regional blockade for surgery, postoperative analgesia, acute/chronic pain control, and even cancer treatments. However, a number of disadvantages are associated with traditional local anesthetic agents as well as routine drug delivery administration ways, such as neurotoxicity, short half-time, and non-sustained release, thereby limiting their application in clinical practice. Successful characterization of drug delivery systems (DDSs) for individual local anesthetic agents can support to achieve more efficient drug release and prolonged duration of action with reduced systemic toxicity. Different types of DDSs involving various carriers have been examined, including micromaterials, nanomaterials, and cyclodextrin. Among them, nanotechnology-based delivery approaches have significantly developed in the last decade due to the low systemic toxicity and the greater efficacy of non-conventional local anesthetics. Multiple nanosized materials, including polymeric, lipid (solid lipid nanoparticles, nanostructured lipid carriers, and nanoemulsions), metallic, inorganic non-metallic, and hybrid nanoparticles, offer a safe, localized, and long-acting solution for pain management and tumor therapy. This review provides a brief synopsis of different nano-based DDSs for local anesthetics with variable sizes and structural morphology, such as nanocapsules and nanospheres. Recent original research utilizing nanotechnology-based delivery systems is particularly discussed, and the progress and strengths of these DDSs are highlighted. A specific focus of this review is the comparison of various nano-based DDSs for local anesthetics, which can offer additional indications for their further improvement. All in all, nano-based DDSs with unique advantages provide a novel direction for the development of safer and more effective local anesthetic formulations.

Fluorescent-Nanoparticle-Impregnated Nanocomposite Polymeric Gels for Biosensing and Drug Delivery Applications

Nanocomposite polymeric gels infused with fluorescent nanoparticles have surfaced as a propitious category of substances for biomedical purposes owing to their exceptional characteristics. The aforementioned materials possess a blend of desirable characteristics, including biocompatibility, biodegradability, drug encapsulation, controlled release capabilities, and optical properties that are conducive to imaging and tracking. This paper presents a comprehensive analysis of the synthesis and characterization of fluorescent-nanoparticle-impregnated nanocomposite polymeric gels, as well as their biomedical applications, such as drug delivery, imaging, and tissue engineering. In this discourse, we deliberate upon the merits and obstacles linked to these substances, encompassing biocompatibility, drug encapsulation, optical characteristics, and scalability. The present study aims to provide an overall evaluation of the potential of fluorescent-nanoparticle-impregnated nanocomposite polymeric gels for biomedical applications. Additionally, emerging trends and future directions for research in this area are highlighted.

Near-Infrared-Activatable PROTAC Nanocages for Controllable Target Protein Degradation and On-Demand Antitumor Therapy

As a novel protein knockdown tool, proteolysis targeting chimeras (PROTACs) can induce potent degradation of target proteins by hijacking E3 ubiquitin ligases. However, the uncontrollable protein disruption of PROTACs is prone to cause "off-target" toxicity after systemic administration. Herein, we designed a photocaged-PROTAC (phoBET1) and loaded it in UCNPs-based mesoporous silica nanoparticles (UMSNs) to construct a NIR light-activatable PROTAC nanocage (UMSNs@phoBET1) for controllable target protein degradation. Upon NIR light (980 nm) irradiation, UMSNs@phoBET1 nanocages could be activated to release active PROTAC via a controlled pattern for degrading bromodomain-containing protein 4 (BRD4) and inducing MV-4-11 cancer cell apoptosis. In vivo experiments demonstrated that UMSNs@phoBET1 nanocages were capable of responding to NIR light in tumor tissues to achieve BRD4 degradation and effectively suppress tumor growth. This NIR light-activatable PROTAC nanoplatform compensates for the current shortcomings of short-wavelength light-controlled PROTACs and presents a paradigm for the precise regulation of PROTACs in living tissues.

Thiol-Disulfide Exchange Coordinates the Release of Nitric Oxide and Dexamethasone for Synergistic Regulation of Intestinal Microenvironment in Colitis

The cell-specific functions of nitric oxide (NO) in the intestinal microenvironment orchestrate its therapeutic effects in ulcerative colitis. While most biomaterials show promise by eliciting the characteristics of NO, the insufficient storage, burst release, and pro-inflammatory side effects of NO remain as challenges. Herein, we report the development of thiol-disulfide hybrid mesoporous organosilica nanoparticles (MONs) that improve the storage and sustained release of NO, broadening the therapeutic window of NO-based therapy against colitis. The tailored NO-storing nanomaterials coordinated the release of NO and the immunoregulator dexamethasone (Dex) in the intestinal microenvironment, specifically integrating the alleviation of oxidative stress in enterocytes and the reversal of NO-exacerbated macrophage activation. Mechanistically, such a synchronous operation was achieved by a self-motivated process wherein the thiyl radicals produced by NO release cleaved the disulfide bonds to degrade the matrix and release Dex via thiol-disulfide exchange. Specifically, the MON-mediated combination of NO and Dex greatly ameliorated intractable colitis compared with 5-aminosalicylic acid, even after delayed treatment. Together, our results reveal a key contribution of synergistic modulation of the intestinal microenvironment in NO-based colitis therapy and introduce thiol-disulfide hybrid nanotherapeutics for the management of inflammatory diseases and cancer.

Recent Advances in Applications of Fluorescent Perylenediimide and Perylenemonoimide Dyes in Bioimaging, Photothermal and Photodynamic Therapy

The emblematic perylenediimide (PDI) motif which was initially used as a simple dye has undergone incredible development in recent decades. The increasing power of synthetic organic chemistry has allowed it to decorate PDIs to achieve highly functional dyes. As these PDI derivatives combine thermal, chemical and photostability, with an additional high absorption coefficient and near-unity fluorescence quantum yield, they have been widely studied for applications in materials science, particularly in photovoltaics. Although PDIs have always been in the spotlight, their asymmetric counterparts, perylenemonoimide (PMI) analogues, are now experiencing a resurgence of interest with new efforts to create architectures with equally exciting properties. Namely, their exceptional fluorescence properties have recently been used to develop novel systems for applications in bioimaging, biosensing and photodynamic therapy. This review covers the state of the art in the synthesis, photophysical characterizations and recently reported applications demonstrating the versatility of these two sister PDI and PMI compounds. The objective is to show that after well-known applications in materials science, the emerging trends in the use of PDI- and PMI-based derivatives concern very specific biomedicinal applications including drug delivery, diagnostics and theranostics.

Fluorescent Probes Based on AIEgen-Mediated Polyelectrolyte Assemblies for Manipulating Intramolecular Motion and Magnetic Relaxivity

Uniting photothermal therapy (PTT) with magnetic resonance imaging (MRI) holds great potential in nanotheranostics. However, the extensively utilized hydrophobicity-driven assembling strategy not only restricts the intramolecular motion-induced PTT, but also blocks the interactions between MR agents and water. Herein, we report an aggregation-induced emission luminogen (AIEgen)-mediated polyelectrolyte nanoassemblies (APN) strategy, which bestows a unique "soft" inner microenvironment with good water permeability. Femtosecond transient spectra verify that APN well activates intramolecular motion from the twisted intramolecular charge transfer process. This de novo APN strategy uniting synergistically three factors (rotational motion, local motion, and hydration number) brings out high MR relaxivity. For the first time, APN strategy has successfully modulated both intramolecular motion and magnetic relaxivity, achieving fluorescence lifetime imaging of tumor spheroids and spatio-temporal MRI-guided high-efficient PTT.

Perylene-Based Reactive Oxygen Species Supergenerator for Immunogenic Photochemotherapy against Hypoxic Tumors

Reactive oxygen species (ROS) can act as cytotoxic radicals to directly kill tumor cells and concurrently trigger immunogenic cell death (ICD) to efficiently achieve tumor therapy. Thus motivated, we herein present one perylene monoamide-based ROS supergenerator (PMIC-NC) that not only induces hypoxia-enhanced Type-I ROS burst aided by proton transients but also triggers Type-I/II ROS production by electron or energy transfer under near-infrared (NIR) light irradiation and also elicits a strong ICD effect. More interesting, the mitochondria- and lung-specific distribution of PMIC-NC also boosts the tumor therapeutic efficiency. As a result, PMIC-NC was employed for NIR-triggered photodynamic therapy, hypoxia-enhanced chemotherapy and also displayed robust immunogenicity for systemic tumor eradication. This work thus contributes one proof-of-concept demonstration of perylene as an integrated therapeutic platform for efficient immunogenic photochemotherapy against hypoxic tumors.

Biocompatible Polymer Nano-Constructs: A Potent Platform for Cancer Theranostics

Nano-constructs of biocompatible polymers have drawn wide attention owing to their potential as theranostics for simultaneous therapy and detection of cancer. The present mini review summarizes various nano-architectures of polymers that have been developed as theranostic agents for the simultaneous treatment and diagnosis of cancer in a single platform. Additionally, research prospects of polymeric cancer theranostics for the future have been highlighted.

Image-guided drug delivery in nanosystem-based cancer therapies

The past decades have shown significant advancements in the development of solid tumor treatment. For instance, implementation of nanosystems for drug delivery has led to a reduction in side effects and improved delivery to the tumor region. However, clinical translation has faced challenges, as tumor drug levels are still considered to be inadequate. Interdisciplinary research has resulted in the development of more advanced drug delivery systems. These are coined "smart" due to the ability to be followed and actively manipulated in order to have better control over local drug release. Therefore, image-guided drug delivery can be a powerful strategy to improve drug activity at the target site. Being able to visualize the inflow of the administered smart nanosystem within the tumor gives the potential to determine the right moment to apply the facilitator to initiate drug release. Here we provide an overview of available nanosystems, imaging moieties, and imaging techniques. We discuss preclinical application of these smart drug delivery systems, the strength of image-guided drug delivery, and the future of personalized treatment.

Perylene-Mediated Electron Leakage in Respiratory Chain to Trigger Endogenous ROS Burst for Hypoxic Cancer Chemo-Immunotherapy

Perylene derivatives can be stimulated by the hypoxic tumor microenvironment to generate radical anion that is proposed to arouse electron exchange with oxidizing substance, and in turn, realize reactive oxygen species (ROS) burst. Here, three perylene therapeutic agents, PDI-NI, PDIB-NI, and PDIC-NI, are developed and it is found that the minimum lowest unoccupied molecular orbital (LUMO) energy level makes PDIC-NI most easily accept electrons from the oxidative respiratory chain to form lots of anions, and the resultant maximum ROS generation, establishing an unambiguous mechanism for the formation of perylene radical anions in the cell, presents solid evidence for LUMO energy level determining endogenous ROS burst. Stirringly, PDIC-NI-induced ROS generation arouses enhanced mitochondrial oxidative stress and concurrently activates immunogenic cell death (ICD), which not only efficiently kills lung tumor cells but also reprograms immunosuppressive tumor microenvironment, including the cytokine secretion, dendritic cell maturation, as well as cytotoxic T lymphocytes activation, to inhibit the growth of xenografted and metastasis tumor, presenting a proof-of-concept demonstration of perylene that acts as an integrated therapeutic agent to well realize hypoxia-activated chemotherapy with ICD-induced immunotherapy on lung cancer.

Carbon dot incorporated mesoporous silica nanoparticles for targeted cancer therapy and fluorescence imaging†

A new and efficient theranostic nanoplatform was developed via a green approach for targeted cancer therapy and fluorescence imaging, without the use of any anticancer chemotherapeutic drugs. Toward this aim, monodisperse and spherical mesoporous silica nanoparticles (MSNs) of approximately 50 nm diameter were first synthesized using the sol–gel method and loaded with hydrothermally synthesized anticancer carbon dots (CDs). The resulting MSNs-CDs were then functionalized with chitosan and targeted by an anti-MUC1 aptamer, using the glutaraldehyde cross-linker, and fully characterized by TEM, FE-SEM, EDS, FTIR, TGA, XRD, and BET analysis. Potent and selective anticancer activity was obtained against MCF-7 and MDA-MB-231 cancer cells with the maximum cell mortalities of 66.2 ± 1.97 and 71.8 ± 3%, respectively, after 48 h exposure with 100 μg mL⁻¹ of the functionalized MSNs-CDs. The maximum mortality of 40.66 ± 1.3% of normal HUVEC cells was obtained under the same conditions. Based on the results of flowcytometry analysis, the apoptotic mediated cell death was recognized as the main anticancer mechanism of the MSNs-CDs. The fluorescence imaging of MCF-7 cancer cells was also studied after exposure with MSNs-CDs. The overall results indicated the high potential of the developed nanoplatform for targeted cancer theranostics.

Efficient cancer therapy and fluorescence imaging was obtained by aptamer targeted mesoporous silica nanoparticles incorporating carbon dots.

Bifunctional tetrazole-carboxylate ligand based Zn(ii) complexes: synthesis and their excellent potential anticancer properties

Transition metal coordination complexes have provided cancer treatment with new insights to overcome the limitations of current chemotherapeutic agents. Utilization of bifunctional tetrazole-carboxylate ligands with Zn(ii) obtained two self-assembled complexes [Zn(HL¹)(bipy)_3/2(H₂O)]·CH₃OH·4(H₂O) (1) (H₃L¹ = 1,3,5-tri(2-carboxymethyltetrazol-5-yl) benzene) and [Zn(L²)₂(H₂O)₂]₂·2H₂O (2) (HL² = (5-pyridin-3-yl-tetrazol-2-yl)-acetic acid). The X-ray diffraction results showed that the two complexes displayed a two-dimensional (2D) layer structure and a one-dimensional (1D) layer structure. Nanocoprecipitation with DSPE-PEG-2000 resulted in the formation of complex nanoparticles (NPS) with excellent water dispersion. In vitro CCK-8 assay indicated the two NPs exert high cytotoxicity and sensitivity and a low half-maximum inhibitory concentration (IC₅₀) towards HeLa than HepG2 cells. In addition, the cytotoxicity was also confirmed by live/dead co-stained experiments. The presented experimental results showed the 1 and 2 NPs were capable of inhibiting cell proliferation in vitro and may help design coordination complex-based anticancer candidates for cancer cells.

Two copper(II) compounds derived from tetrazole carboxylates for chemodynamic therapy against hepatocellular carcinoma cells

Two Cu(II) compounds based on tetrazole-carboxylate ligands, [Cu(phtza)2(H2O)2]∙3H2O (1) and [Cu(atzipa)2]∙2H2O (2) (phtza = 2,2'-(5,5'-(1,3-phenylene)bis(2H-tetrazole-5,2-diyl))diacetate, atzipa = 3-(5-amino-1H-tetrazol-1-yl)isopropanoic anion), were designed and synthesized by hydrothermal reactions. The X-ray diffraction results show that the two compounds show two-dimensional (2D) layer structures. Nanoprecipitation with 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000] (DSPE-PEG-2000) contributes to the formation of the nanoparticles (NPs) with excellent water dispersity. In vitro study indicates that the two NPs exert considerable cytotoxicity toward human hepatocellular carcinoma cells (HepG2 and Huh7) with low half-maximal inhibitory concentration (IC50). However, the cytotoxicity of such NPs is negligible in normal cells (HL-7702). The cytotoxicity of these NPs was also investigated by the flow cytometry and Calcein-AM/PI (live/dead) co-stained experiments. The results promise the great potential of these NPs for chemodynamic therapy against cancer cells.

"One Stone, Four Birds" Ion Engineering to Fabricate Versatile Core-Shell Organosilica Nanoparticles for Intelligent Nanotheranostics

Developing effective intelligent nanotheranostics is highly desirable for cancer treatment but remains challenging. In this study, an acidic tumor microenvironment-activated organosilica nanosystem, namely AD-Cu-DOX-HA, is straightforwardly constructed, which is composed of aggregation-induced emission (AIE)-active photosensitizer, copper ion-engineered aminosilica, direct coordination polymer of doxorubicin (DOX), and targeting component hyaluronic acid (HA). AD-Cu-DOX-HA is able to accurately distinguish cancer cells over normal cells; meanwhile, it simultaneously exhibits selective accumulation and copper ion-mediated rapid disassembly and turn-on fluorescence in tumor tissue, consequently achieving efficient tumor diagnosis and tumor-growth inhibition through fluorescence imaging-navigated synergetic photodynamic therapy, copper ion-mediated chemodynamic therapy, and DOX-enabled chemotherapy. This work thus brings fresh insight into the exploration of versatile theranostics and presents a momentous advance for potential clinical cancer treatment.

Biodegradable magnesium ion-doped silica-based molecularly imprinted nanoparticles for targeting tumor cells to drugs controlled release and recognition mechanism research

Herein, we designed and constructed a novel biodegradable molecularly imprinted nanoparticles (Mg-SMSNs/DOX-Ce6 @MIPs) using a new degradable functional monomer prepared by glycerol and lactide, on magnesium ion-doped stellated mesoporous silica nanoparticles (Mg-SMSNs). These nanoparticles loaded with the anticancer drug doxorubicin (DOX) and chlorin e6 (Ce6) were used to target sialic acid (SA) overexpressed on the surface of tumor cells and release drugs in response to the tumor microenvironment. The molecularly imprinted layer avoided premature drug leakage, meanwhile, the large number of ester bonds contained in the functional monomers in the layer degraded by protonation in the tumor microenvironment to expose the drugs. Mg²⁺ doping in SMSNs enhanced the degradation performance in tumor microenvironment to achieve tumor-responsive drug release. The multifunctional monomers increased the interaction with SA, enhanced the binding force, and accurately targeted recognition was obtained. The recognition mechanism of Mg-SMSNs/DOX-Ce6 @MIPs to SA and drug release were investigated by model analysis. The cytotoxicity and cellular targeting of Mg-SMSNs/DOX-Ce6 @MIPs revealed that Mg-SMSNs/DOX-Ce6 @MIPs could specifically recognize SA to target MCF-7 tumor cells without interference. Under laser irradiation, Ce6 and DOX could achieve synergistic treatment to tumor cells. Mg-SMSNs/DOX-Ce6 @MIPs present good biological abilities in terms of active targeting, pH-responsiveness, antitumor efficiency and biocompatibility.

Radiotherapy Reduces N-Oxides for Prodrug Activation in Tumors

Precisely activating chemotherapeutic prodrugs in a tumor-selective manner is an ideal way to cure cancers without causing systemic toxicities. Although many efforts have been made, developing spatiotemporally controllable activation methods is still an unmet challenge. Here, we report a novel prodrug activation strategy using radiotherapy (X-ray). Due to its precision and deep tissue penetration, X-ray matches the need for altering molecules in tumors through water radiolysis. We first demonstrated that N-oxides can be effectively reduced by hydrated electrons (e^-_aq) generated from radiation both in tubes and living cells. A screening is performed to investigate the structure-reduction relationship and mechanism of the e^-_aq-mediated reductions. We then apply the strategy to activate N-oxide prodrugs. The anticancer drug camptothecin (CPT)-based N-oxide prodrug shows a remarkable anticancer effect upon activation by radiotherapy. This radiation-induced in vivo chemistry may enable versatile designs of radiotherapy-activated prodrugs, which are of remarkable clinical relevance, as over 50% of cancer patients take radiotherapy.

Biodegradable Metal-Organic-Framework-Gated Organosilica for Tumor-Microenvironment-Unlocked Glutathione-Depletion-Enhanced Synergistic Therapy

The clinical employment of cisplatin (cis-diamminedichloroplatinum(II) (CDDP)) is largely constrained due to the non-specific delivery and resultant serious systemic toxicity. Small-sized biocompatible and biodegradable hollow mesoporous organosilica (HMOS) nanoparticles show superior advantages for targeted CDDP delivery but suffer from premature CDDP leakage. Herein, the smart use of a bimetallic Zn²⁺ /Cu²⁺ co-doped metal-organic framework (MOF) is made to block the pores of HMOS for preventing potential leakage of CDDP and remarkably increasing the loading capacity of HMOS. Once reaching the acidic tumor microenvironment (TME), the outer MOF can decompose quickly to release CDDP for chemotherapy against cancer. Besides, the concomitant release of dopant Cu²⁺ can deplete the intracellular glutathione (GSH) for increased toxicity of CDDP as well as catalyzing the decomposition of intratumoral H₂ O₂ into highly toxic •OH for chemodynamic therapy (CDT). Moreover, the substantially reduced GSH can also protect the yielded •OH from scavenging and thus greatly improve the •OH-based CDT effect. In addition to providing a hybrid HMOS@MOF nanocarrier, this study is also expected to establish a new form of TME-unlocked nanoformula for highly efficient tumor-specific GSH-depletion-enhanced synergistic chemotherapy/chemodynamic therapy.

Photoactivatable nanogenerators of reactive species for cancer therapy

In recent years, reactive species-based cancer therapies have attracted tremendous attention due to their simplicity, controllability, and effectiveness. Herein, we overviewed the state-of-art advance for photo-controlled generation of highly reactive radical species with nanomaterials for cancer therapy. First, we summarized the most widely explored reactive species, such as singlet oxygen, superoxide radical anion (O2 ●-), nitric oxide (●NO), carbon monoxide, alkyl radicals, and their corresponding secondary reactive species generated by interaction with other biological molecules. Then, we discussed the generating mechanisms of these highly reactive species stimulated by light irradiation, followed by their anticancer effect, and the synergetic principles with other therapeutic modalities. This review might unveil the advantages of reactive species-based therapeutic methodology and encourage the pre-clinical exploration of reactive species-mediated cancer treatments.

Intelligent Pore Switch of Hollow Mesoporous Organosilica Nanoparticles for High Contrast Magnetic Resonance Imaging and Tumor-Specific Chemotherapy

Hollow mesoporous organosilica nanoparticles (HMONs) are widely considered as a promising drug nanocarrier, but the loaded drugs can easily leak from HMONs, resulting in the considerably decreased drug loading capacity and increased biosafety risk. This study reports the smart use of core/shell Fe₃O₄/Gd₂O₃ (FG) hybrid nanoparticles as a gatekeeper to block the pores of HMONs, which can yield an unreported large loading content (up to 20.4%) of DOX. The conjugation of RGD dimer (R2) onto the DOX-loaded HMON with FG capping (D@HMON@FG@R2) allowed for active tumor-targeted delivery. The aggregated FG in D@HMON@FG@R2 could darken the normal tissue surrounding the tumor due to the high r₂ value (253.7 mM^-1 s^-1) and high r₂/r₁ ratio (19.13), and the intratumorally released FG as a result of reducibility-triggered HMON degradation could brighten the tumor because of the high r₁ value (20.1 mM^-1 s^-1) and low r₂/r₁ ratio (7.01), which contributed to high contrast magnetic resonance imaging (MRI) for guiding highly efficient tumor-specific DOX release and chemotherapy.

Perylene diimide-based treatment and diagnosis of diseases

Integrated treatment using imaging technology to monitor biological processes for the precise treatment and diagnosis of diseases to improve treatment outcomes is becoming a hot topic. Accordingly, perylene diimide (PDI) has excellent photothermal conversion and photostability, which can be used as a good material for disease treatment and diagnosis. Herein, we review the latest research progress on the real-time diagnosis of related diseases based on perylene diimide probes in the aspects of bioimaging, detection of biomarkers and determination of the pH in living cells. Furthermore, perylene diimide-based multifunctional nano-delivery systems are particularly emphasized, showing great therapeutic potential in the field of image-guided combination therapy in tumor therapy. Finally, the great opportunities and challenges still faced by perylene diimide before entering the clinic are comprehensively analyzed.

Theranostic Heterodimeric Prodrug with Dual-Channel Fluorescence Turn-On and Dual-Prodrug Activation for Synergistic Cancer Therapy

Theranostic prodrugs that can precisely monitor drug activation with synergistic therapeutic effects are highly desirable for personalized medicine. In this study, a theranostic heterodimeric prodrug, CyNH-SS-DOX, with synchronous and independent dual-channel fluorescence turn-on and dual-prodrug activation for synergistic cancer therapy is developed. A hemicyanine fluorescent drug, CyNH₂ , with good therapeutic effects found in this work, is conjugated to doxorubicin (DOX) through a disulfide linker to form CyNH-SS-DOX. Before activation, both the fluorescence of DOX and CyNH₂ are in the off state and the toxicity is low. In the presence of intracellular glutathione, both the fluorescence of DOX and CyNH₂ at different channels are turned on. Meanwhile, DOX and CyNH₂ are activated in a synergistic anticancer effect. It is believed that CyNH-SS-DOX is promising for monitoring prodrug activation in dual-fluorescence channels and for enhancing therapeutic efficacy with few side effects.

Self-assembled semiconducting polymer based hybrid nanoagents for synergistic tumor treatment

There is an impending need for the development of carrier-free nanosystems for single laser triggered activation of phototherapy, as such approach can overcome the drawbacks associated with irradiation by two distinct laser sources for avoiding prolonged treatment time and complex treatment protocols. Herein, we developed a self-assembled nanosystem (SCP-CS) consisting of a new semiconducting polymer (SCP) and encapsulated ultrasmall CuS (CS) nanoparticles. The SCP component displays remarkable near infrared (NIR) induced photothermal ability, enhanced reactive oxygen species (ROS) generation, and incredible photoacoustic (PA) signals upon activation by 808 nm laser for phototherapy mediated cancer ablation. The CuS component improves the PA imaging ability of SCP-CS, and also enhances photo-induced chemodynamic efficacy. Attributed to promoted single laser-triggered hyperthermia and enhanced ROS generation, the SCP-CS nanosystem shows effective intracellular uptake and intratumoral accumulation, enhanced tumor suppression with reduced treatment time, and devoid of any noticeable toxicity.

Preparation of cellulose-based electrospun fluorescent nanofibres doped with perylene encapsulated in silica nanoparticles for potential flexible electronics

Novel fluorescent nanofibres were developed via the electrospinning of chromophore-doped cellulose. Two different perylene-doped cellulose fluorescent fibres were fabricated using cellulose as a host material and perylene dye derivatives as active dopants. Fluorescent cellulose nanofibres were prepared via the electrospinning technique using two different perylene dyes, including perylene diimide and perylene mono-imide sodium/potassium salts. The generated fluorescent silica nanoparticles exhibited diameters varying in the range 80-180 nm. The generated electrospun fluorescent nanofibrous structures displayed smooth surfaces with average diameters of 200-300 nm for cellulose comprising perylene diimide and sodium/potassium salts of perylene mono-imide dyes, respectively, dispersed uniformly in the cellulose matrix. The generated fluorescent nanoparticles and nanofibres were characterized by different standard methods, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), fluorescent optical microscope (FOM) and Fourier-transform infrared spectra (FT-IR). The fluorescence properties of the fabricated cellulose nanofibres were explored. Those fluorescent nanofibres pave the way for the development of promising textile fluorescence materials, such as flexible displays, photonics, and optical devices.

An Update on Mesoporous Silica Nanoparticle Applications in Nanomedicine

The efficient and safe delivery of therapeutic drugs, proteins, and nucleic acids are essential for meaningful therapeutic benefits. The field of nanomedicine shows promising implications in the development of therapeutics by delivering diagnostic and therapeutic compounds. Nanomedicine development has led to significant advances in the design and engineering of nanocarrier systems with supra-molecular structures. Smart mesoporous silica nanoparticles (MSNs), with excellent biocompatibility, tunable physicochemical properties, and site-specific functionalization, offer efficient and high loading capacity as well as robust and targeted delivery of a variety of payloads in a controlled fashion. Such unique nanocarriers should have great potential for challenging biomedical applications, such as tissue engineering, bioimaging techniques, stem cell research, and cancer therapies. However, in vivo applications of these nanocarriers should be further validated before clinical translation. To this end, this review begins with a brief introduction of MSNs properties, targeted drug delivery, and controlled release with a particular emphasis on their most recent diagnostic and therapeutic applications.

Coordination and Redox Dual-Responsive Mesoporous Organosilica Nanoparticles Amplify Immunogenic Cell Death for Cancer Chemoimmunotherapy

Amplifying the chemotherapy-driven immunogenic cell death (ICD) for efficient and safe cancer chemoimmunotherapy remains a challenge. Here, a potential ICD nanoamplifier containing diselenide-bridged mesoporous organosilica nanoparticles (MONs) and chemotherapeutic ruthenium compound (KP1339) to achieve cancer chemoimmunotherapy is tailored. KP1339-loaded MONs show controlled drug release profiles via glutathione (GSH)-responsive competitive coordination and matrix degradation. High concentration of MONs selectively evoked reactive oxygen species production, GSH depletion, and endoplasmic reticulum stress in cancer cells, thus amplifying the ICD of KP1339 and boosting robust antitumor immunological responses. After the combination of PD-L1 checkpoint blockade, cancer cell membrane-cloaked KP1339-loaded MONs not only regress primary tumor growth with low systemic toxicity, but also inhibit distant tumor growth and pulmonary metastasis of breast cancer. The results have shown the potential of coordination and redox dual-responsive MONs boosting amplified ICD for cancer chemoimmunotherapy.

Periodic Mesoporous Ionosilica Nanoparticles for Green Light Photodynamic Therapy and Photochemical Internalization of siRNA

We report periodic mesoporous ionosilica nanoparticles (PMINPs) as versatile nano-objects for imaging, photodynamic therapy (PDT), and efficient adsorption and delivery of small interfering RNA (siRNA) into breast cancer cells. In order to endow these nanoparticles with PDT and siRNA photochemical internalization (PCI) properties, a porphyrin derivative was integrated into the ionosilica framework. For this purpose, we synthesized PMINPs via hydrolysis-cocondensation procedures from oligosilylated ammonium and porphyrin precursors. The formation of these nano-objects was proved by transmission electron microscopy. The formed nanoparticles were then thoroughly characterized via solid-state NMR, nitrogen sorption, dynamic light scattering, and UV-vis and fluorescence spectroscopies. Our results indicate the formation of highly porous nanorods with a length of 108 ± 9 nm and a width of 54 ± 4 nm. A significant PDT effect of type I mechanism (95 ± 2.8% of cell death) was observed upon green light irradiation in nanoparticle-treated breast cancer cells, while the blue light irradiation caused a significant phototoxic effect in non-treated cells. Furthermore, PMINPs formed stable complexes with siRNA (up to 24 h), which were efficiently internalized into the cells after 4 h of incubation mostly with the energy-dependent endocytosis process. The PCI effect was obvious with green light irradiation and successfully led to 83 ± 1.1% silencing of the luciferase gene in luciferase-expressing breast cancer cells, while no gene silencing effect was observed with blue light irradiation. The present work highlights the high potential of porphyrin-doped PMINPs as multifunctional nanocarriers for nucleic acids, such as siRNA, with a triple ability to perform imaging, PDT, and PCI.

Regulating Twisted Skeleton to Construct Organ-Specific Perylene for Intensive Cancer Chemotherapy

The systemic use of pharmaceutical drugs for cancer patients is a compromise between desirable therapy and side effects because of the intrinsic shortage of organ-specific pharmaceutical drug. Design and construction of pharmaceutical drug to achieve the organ-specific delivery is thus desperately desirable. We herein regulate perylene skeleton to effect organ-specificity and present an example of lung-specific distribution on the basis of bay-twisted PDIC-NC. We further demonstrate that PDIC-NC can target into mitochondria to act as cellular respiration inhibitor, inducing insufficient production of adenosine triphosphate, promoting endogenous H₂ O₂ and ^. OH burst, elevating calcium overload, efficiently triggering the synergistic apoptosis, autophagy and endoplasmic reticulum stress of lung cancer cells. The antitumor performance of PDIC-NC is verified on in vivo xenografted, metastasis and orthotopic lung cancer, presenting overwhelming evidences for potentially clinical application. This study contributes a proof-of-concept demonstration of twisted perylene to well attain lung-specific distribution, and meanwhile achieves intensive lung cancer chemotherapy.

Multifunctional theranostic nanoparticles for biomedical cancer treatments - A comprehensive review

Modern-day search for the novel agents (their preparation and consequent implementation) to effectively treat the cancer is mainly fuelled by the historical failure of the conventional treatment modalities. Apart from that, the complexities such as higher rate of cell mutations, variable tumor microenvironment, patient-specific disparities, and the evolving nature of cancers have made this search much stronger in the latest times. As a result of this, in about two decades, the theranostic nanoparticles (TNPs) - i.e., nanoparticles that integrate therapeutic and diagnostic characteristics - have been developed. The examples for TNPs include mesoporous silica nanoparticles, luminescence nanoparticles, carbon-based nanomaterials, metal nanoparticles, and magnetic nanoparticles. These TNPs have emerged as single and powerful cancer-treating multifunctional nanoplatforms, as they widely provide the necessary functionalities to overcome the previous/conventional limitations including lack of the site-specific delivery of anti-cancer drugs, and real-time continuous monitoring of the target cancer sites while performing therapeutic actions. This has been mainly possible due to the association of the as-developed TNPs with the already-available unique diagnostic (e.g., luminescence, photoacoustic, and magnetic resonance imaging) and therapeutic (e.g., photothermal, photodynamic, hyperthermia therapy) modalities in the biomedical field. In this review, we have discussed in detail about the recent developments on the aforementioned important TNPs without/with targeting ability (i.e., attaching them with ligands or tumor-specific antibodies) and also the strategies that are implemented to increase their tumor accumulation and to enhance their theranostic efficacies for effective biomedical cancer treatments.

Photoactivatable metabolic warheads enable precise and safe ablation of target cells in vivo

Photoactivatable molecules enable ablation of malignant cells under the control of light, yet current agents can be ineffective at early stages of disease when target cells are similar to healthy surrounding tissues. In this work, we describe a chemical platform based on amino-substituted benzoselenadiazoles to build photoactivatable probes that mimic native metabolites as indicators of disease onset and progression. Through a series of synthetic derivatives, we have identified the key chemical groups in the benzoselenadiazole scaffold responsible for its photodynamic activity, and subsequently designed photosensitive metabolic warheads to target cells associated with various diseases, including bacterial infections and cancer. We demonstrate that versatile benzoselenadiazole metabolites can selectively kill pathogenic cells - but not healthy cells - with high precision after exposure to non-toxic visible light, reducing any potential side effects in vivo. This chemical platform provides powerful tools to exploit cellular metabolic signatures for safer therapeutic and surgical approaches.

Mesoporous Silica Nanoparticles: Properties and Strategies for Enhancing Clinical Effect

Due to the theragnostic potential of mesoporous silica nanoparticles (MSNs), these were extensively investigated as a novel approach to improve clinical outcomes. Boasting an impressive array of formulations and modifications, MSNs demonstrate significant in vivo efficacy when used to identify or treat myriad malignant diseases in preclinical models. As MSNs continue transitioning into clinical trials, a thorough understanding of the characteristics of effective MSNs is necessary. This review highlights recent discoveries and advances in MSN understanding and technology. Specific focus is given to cancer theragnostic approaches using MSNs. Characteristics of MSNs such as size, shape, and surface properties are discussed in relation to effective nanomedicine practice and projected clinical efficacy. Additionally, tumor-targeting options used with MSNs are presented with extensive discussion on active-targeting molecules. Methods for decreasing MSN toxicity, improving site-specific delivery, and controlling release of loaded molecules are further explained. Challenges facing the field and translation to clinical environments are presented alongside potential avenues for continuing investigations.

Engineered non-invasive functionalized dendrimer/dendron-entrapped/complexed gold nanoparticles as a novel class of theranostic (radio)pharmaceuticals in cancer therapy

Nanomedicine represents a very significant contribution in current cancer treatment; in addition to surgical intervention, radiation and chemotherapeutic agents that unfortunately also kill healthy cells, inducing highly deleterious and often life-threatening side effects in the patient. Of the numerous nanoparticles used against cancer, gold nanoparticles had been developed for therapeutic applications. Inter alia, a large variety of dendrimers, i.e. soft artificial macromolecules, have turned up as non-viral functional nanocarriers for entrapping drugs, imaging agents, and targeting molecules. This review will provide insights into the design, synthesis, functionalization, and development in biomedicine of engineered functionalized hybrid dendrimer-tangled gold nanoparticles in the domain of cancer theranostic. Several aspects are highlighted and discussed such as 1) dendrimer-entrapped gold(0) hybrid nanoparticles for the targeted imaging and treatment of cancer cells, 2) dendrimer encapsulating gold(0) nanoparticles (Au DENPs) for the delivery of genes, 3) Au DENPs for drug delivery applications, 4) dendrimer encapsulating gold radioactive nanoparticles for radiotherapy, and 5) dendrimer/dendron-complexed gold(III) nanoparticles as technologies to take down cancer cells.

Molecular engineering to boost the photothermal effect of conjugated oligomer nanoparticles

Photothermal therapy has great potential in the treatment of diseases; however, the photothermal property is a key factor limiting the therapeutic effect of photothermal materials. Most strategies to improve the photothermal performance of photothermal materials focus on increasing their photothermal conversion efficiency (PCE) by promoting the non-radiative transition process. However, a strong ability to absorb light is also a significant factor to enhance the photothermal performance of materials because it determines the amount of acquired energy to transform to heat. Therefore, in this work, we utilized molecular engineering to introduce ethynyl into the molecular structure of conjugated molecules to significantly enhance their ability to absorb light and improve their photothermal performance. The M2-NPs made of the conjugated oligomer named M2 with ethynyl exhibited a two-fold greater mass extinction coefficient (30.26 L g^-1 cm^-1) than that of nanoparticles M1-NPs with a similar structure but no ethynyl (15.34 L g^-1 cm^-1). Furthermore, M2-NPs could kill 97% of bacteria at a concentration of 7.0 μg mL^-1, which is less than that of M1-NPs (13.0 μg mL^-1). In addition, M2-NPs could successfully treat the infected wounds in mice with good biosafety. This provides a new idea for effectively improving the photothermal performance of photothermal materials via molecular design and inspires the further development of novel superior photothermal agents.

Benzene-Bridged Organosilica Modified Mesoporous Silica Nanoparticles via an Acid-Catalysis Approach

Surface functionalization of mesoporous silica nanoparticles is important for their applications but fairly challenging using benzene-bridged organosilane as the precursor through the postsynthesis approach. Herein, we report an acid-catalysis approach for the postmodification of benzene-bridged organosilica onto the surface of large-pore mesoporous silica nanoparticles. By using HCl (∼1 M) as the acid catalyst in a tetrahydrofuran solvent, the self-assembly of the bridged organosilica precursor is avoided, while surface modification of mesoporous silica nanoparticles is promoted with controllable organic contents and retained large pore sizes. This strategy can also be applied to the postmodification of organosilica with end benzene groups. The strategy developed in this study is expected to be applied for the postmodification of other organosilica precursors with various functions.

Hybrid Nanosystems for Biomedical Applications

Inorganic/organic hybrid nanosystems have been increasingly developed for their versatility and efficacy at overcoming obstacles not readily surmounted by nonhybridized counterparts. Currently, hybrid nanosystems are implemented for gene therapy, drug delivery, and phototherapy in addition to tissue regeneration, vaccines, antibacterials, biomolecule detection, imaging probes, and theranostics. Though diverse, these nanosystems can be classified according to foundational inorganic/organic components, accessory moieties, and architecture of hybridization. Within this Review, we begin by providing a historical context for the development of biomedical hybrid nanosystems before describing the properties, synthesis, and characterization of their component building blocks. Afterward, we introduce the architectures of hybridization and highlight recent biomedical nanosystem developments by area of application, emphasizing hybrids of distinctive utility and innovation. Finally, we draw attention to ongoing clinical trials before recapping our discussion of hybrid nanosystems and providing a perspective on the future of the field.