Tri-stimuli-responsive biodegradable theranostics for mild hyperthermia enhanced chemotherapy

Surface Engineering of Metal-Organic Framework as pH-/NIR-Responsive Nanocarrier for Imaging-Guided Chemo-Photothermal Therapy

BACKGROUND

Metal-organic frameworks (MOFs) have attracted intensive research interest in the biomedical field because of their unique properties. However, in order to realize the high loading capacity and therapeutic efficacy, it is still urgent to develop a multifunctional MOFs-based nanoplatform.

MATERIALS AND METHODS

Herein, a pH/near-infrared (NIR) dual-responsive drug delivery system based on zeolitic imidazolate framework-8 (ZIF-8) is constructed for synergistic chemo-photothermal therapy and dual-modal magnetic resonance (MR)/photoacoustic (PA) imaging. The doxorubicin hydrochloride (DOX) is embedded into ZIF-8 through one-pot method, and the resultant ZIF-8/DOX is then successively modified with polydopamine, Mn ions and poly(ethylene glycol). The obtained ZIF-8/DMPP is systematically characterized, and both its in vitro and in vivo biological effects are evaluated in detail.

RESULTS

The ZIF-8/DMPP possesses a high drug-loading content of 18.9% and displays appropriate size and morphology. The pH-dependent degradation and drug release behavior of prepared ZIF-8/DMPP are confirmed. Importantly, the results demonstrate that the photothermal effect of ZIF-8/DMPP under NIR laser irradiation can significantly accelerate its drug releasing rate, further improving the intracellular drug concentrations. Thereafter, the augmented chemotherapeutic efficiency by photothermal effect against cancer cells is verified both in vitro and in vivo. Besides, the favorable MR and PA imaging capacity of ZIF-8/DMPP is also evidenced on the tumor model.

CONCLUSION

Taken together, the surface engineering of ZIF-8-based nanocarrier in this work offers a promising strategy for the multifunctional MOFs-based drug delivery system.

Biodegradable Periodic Mesoporous Organosilica (BPMO) Loaded with Daunorubicin: A Promising Nanoparticle-Based Anticancer Drug

Biodegradable periodic mesoporous organosilica (BPMO) nanoparticles have emerged as a promising type of nanocarrier for drug delivery, given the biodegradable feature is advantageous for clinical translation. In this paper, we report synthesis and characterization of daunorubicin (DNR) loaded BPMO. DNR was loaded onto rhodamine B-labeled BPMO that contain tetrasulfide bonds. Tumor spheroids and chicken egg tumor models were used to characterize the activity in biological settings. In the first experiment we examined the uptake of BPMO into tumor spheroids prepared from ovarian cancer cells. BPMO were efficiently taken up into tumor spheroids and inhibited their growth. In the chicken egg tumor model, intravenous injection of DNR-loaded BPMO led to the elimination of ovarian tumor. Lack of adverse effect on organs such as lung appears to be due to excellent tumor accumulation of BPMO. Thus, DNR-loaded BPMO represents a promising nanodrug compared with free DNR currently used in cancer therapy. OK.

Overview of stimuli-responsive mesoporous organosilica nanocarriers for drug delivery

The application of nanomaterials is regarded nowadays as a highly promising approach for overcoming the limitations of the currently available cancer treatments, contributing for the creation of more effective, precise, and safer therapies. In the last years, organosilica nanoparticles arisen as alternatives to the most common mesoporous silica nanoparticles. The organosilica nanoparticles combine the advantages of the mesoporous silica, such as structural stability and mesoporous structure, with the increased biocompatibility and biodegradability of organic materials. Therefore, the variety of organic bridges that can be incorporated into the silica matrix allowed the development of new and exciting compositions, properties, and functions for improving the therapeutic effectiveness of the anticancer nanomedicines. In this review, the strategies that have been explored to create stimuli-responsive organosilica-based drug delivery systems are highlighted, describing the practical approaches and mechanisms controlling the drug release. Additionally, the organosilica nanoparticles surface modifications aimed for increasing the blood circulation time and the tumor targeting are also described.

Albumin-bioinspired iridium oxide nanoplatform with high photothermal conversion efficiency for synergistic chemo-photothermal of osteosarcoma

Protein-based nanocarriers with inherent biocompatibility have been widely served as building blocks to construct versatile therapeutic nanoplatforms. Herein, bovine serum albumin-iridium oxide nanoparticles (denoted BSA-IrO₂ NPs) are successfully synthesized via one-step biomineralization approach. The BSA-IrO₂ NPs exhibits uniform size (40 nm), superb biocompatibility and high drug loading capacity for doxorubicin (27.4 wt%). Under near-infrared (NIR) laser irradiation, the as-prepared BSA-IrO₂ NPs exhibited high photothermal conversion ability (54.3%) and good photostability. The in vitro drug release experiments displayed pH and NIR laser -triggered DOX release profiles, which could enhance the therapeutic anticancer effect. By utilizing this DOX loaded nanoplatform, effective synergistic chemo-photothermal therapy against human osteosarcoma can be realized, which has been systematically verified both in vitro and in vivo. Notably, in vivo pharmacokinetics studies showed that BSA-IrO₂@DOX had prolonged blood circulation time due to the BSA component can improve the stealthiness of the nanoparticles during the blood circulation. Meanwhile, in vitro and in vivo toxicity studies demonstrated that the BSA-IrO₂ NPs can act as biocompatible agents for drug delivery and cancer therapy. Therefore, this work presents a biomineralized iridium-based NPs with remarkable features and be used as a very potential therapeutic nanoplatform for cancer treatment.

Responsive agarose hydrogel incorporated with natural humic acid and MnO2nanoparticles for effective relief of tumor hypoxia and enhanced photo-induced tumor therapy

In spite of widespread applications of nano-photosensitizers, poor tumor penetration and severe hypoxia in the tumor microenvironment (TME) always result in an undesirable therapeutic outcome of photodynamic therapy (PDT).

Synergistic photothermal/photodynamic suppression of prostatic carcinoma by targeted biodegradable MnO2 nanosheets

The biodegradability and clearance of metal-based nanomaterials have been questioned worldwide, which have greatly limited their clinical translation. Herein, ultrathin manganese dioxide (MnO2) nanosheets with broad near-infrared (NIR) absorption and pH-dependent degradation properties were prepared. After being modified with polyethylene glycol-cyclic arginine-glycineaspartic acid tripeptide (PEG-cRGD), the MnO2 nanosheets were then used as photothermal agent and nanocarrier to encapsulate chlorin e6 (Ce6) for targeted photothermal (PTT) and photodynamic (PDT) of cancer. As expected, the MnO2-PEG-cRGD nanosheets show high Ce6 loading capacity (351 mg/g), superb photothermal conversion performance (37.2%) and excellent colloidal stability. These nanosheets also exhibit pH-dependent and NIR-induced Ce6 release. Furthermore, the MnO2 nanosheets can be degraded by reacting with hydrogen peroxide in the acidic microenvironment, which are able to elevate the oxygen concentration in situ and thus reverses the tumor hypoxia. Thanks to these favorable properties and the cRGD-mediated tumor-targeted ability, the fabricated MnO2-PEG-cRGD/Ce6 nanocomposites can be effectively up taken by alpha-v beta-3 (αvβ3) integrin over-expressed prostatic carcinoma PC3 cells and achieve favorable therapeutic outcomes under a single 660 nm NIR laser, which is also verified by in vitro studies. The biodegradable MnO2-PEG-cRGD/Ce6 nanosheets developed in this work can be a promising nanoplatform for synergetic PTT/PDT cancer therapy.

A multifunctional nanoplatform based on MoS2-nanosheets for targeted drug delivery and chemo-photothermal therapy

Synergistic tumor treatment has recently attracted more and more attention due to its remarkable therapeutic effect. Herein, a multifunctional drug delivery system based on hyaluronic acid (HA) targeted dual stimulation responsive MoS₂ nanosheets (HA-PEI-LA-MoS₂-PEG, HPMP) for active interaction with CD44 receptor positive MCF-7 cells is reported. Melanin (Mel), a new type of photothermal agent and doxorubicin (DOX) are both loaded onto the HPMP nanocomposite and can be released by mild acid or hyperthermia. The prepared HPMP nanocomposite has a uniform hydrodynamic diameter (104 nm), a high drug loading (944.3 mg.g^-1 HPMP), a remarkable photothermal effect (photothermal conversion efficiency: 55.3%) and excellent biocompatibility. The DOX release from HPMP@(DOX/Mel) can be precisely controlled by the dual stimuli of utilizing the acidic environment in the tumor cells and external laser irradiation. Meanwhile, loading of Mel onto the surface can enhance the photothermal effect of the MoS₂ nanosheets. In vitro experiments showed that the HPMP@(DOX/Mel) nanoplatform could efficiently deliver DOX into MCF-7 cells and demonstrated enhanced cytotoxicity compared to that of the non-targeted nanoplatform. In vivo experiments in a breast cancer model of nude mice further confirmed that the HPMP@(DOX/Mel) significantly inhibited tumor growth under near infrared (NIR) laser irradiation, which is superior to any single therapy. In summary, this flexible nanoplatform, based on multi-faceted loaded MoS₂ nanosheets, exhibits considerable potential for efficient pH/NIR-responsive targeted drug delivery and chemo-photothermal synergistic tumor therapy.

A near-infrared light-controlled smart nanocarrier with reversible polypeptide-engineered valve for targeted fluorescence-photoacoustic bimodal imaging-guided chemo-photothermal therapy

Despite burgeoning development of nanoplatform made in the past few years, it remains a challenge to produce drug nanocarrier that enables requested on/off drug release. Thus, this study aimed to develop an ideal near-infrared light-triggered smart nanocarrier for targeted imaging-guided treatment of cancer that tactfully integrated photothermal therapy with chemotherapy to accurately control drug release time and dosage. Methods: This delivery system was composed of Ag₂S QD coating with dendritic mesoporous silica (DMSN), which acted as nanocarrier of doxorubicin localized inside pores. To provide the nanocarrier with controlled release capability, a polypeptide-engineered that structure was reversible to photothermal effect of Ag₂S QD, was covalently grafted to the external surface of drug-loaded DMSN. Results: This nanocarrier with the size of 40~60 nm had satisfactory biocompatibility and photothermal conversion efficiency up to 28.35%. Due to acidity-triggered charge reversal of polypeptide, which significantly extended circulation time and improved targeting ability, fluorescence and photoacoustic signals were still obvious at tumor site post-24 h by tail vein injection and chemo-photothermal synergistic therapy obviously enhanced antitumor efficacy. Mild PTT with multiple short-term exposures not only reduced the side effect of overdose drug but also avoided skin damage caused by long-term irradiation. Conclusion: By adjusting irradiation time and on/off cycle, multiple small amount local drug release reduced the side effect of overdose drug and skin damage. This novel approach provided an ideal near-infrared light-triggered nanocarrier with accurate control of area, time, and especially dosage.

Hyaluronic Acid-Modified Porous Carbon-Coated Fe3O4 Nanoparticles for Magnetic Resonance Imaging-Guided Photothermal/Chemotherapy of Tumors

Chemotherapy is an effective method for treating cancer, clinically. However, side effects of drug and multidrug resistance restrict its application. In recent years, the combined treatment of chemotherapy and photothermal therapy (PTT) is becoming a promising method for treating cancer. PTT utilizes nanomaterials absorbing near-infrared light and producing heat to acquire advanced hyperthermia strategy for cancer treatment. Carbon nanomaterials with good biocompatibility, high surface area, and excellent photothermal properties are an excellent nanoplatform for drug delivery and PTT. Herein, porous carbon-coated magnetite nanoparticles (PCCMNs) were successfully synthesized by a one-pot solvothermal method. Magnetite, a contrast agent, can be used for magnetic resonance imaging. Hyaluronic acid was used to modify the PCCMNs to achieve targeted therapy. The obtained nanohybrid with a good photothermal effect can realize combined PTT/chemotherapy and will be a promising nanoplatform for high efficacy theranostics.

Biodegradable nanotheranostics with hyperthermia-induced bubble ability for ultrasound imaging-guided chemo-photothermal therapy

Background

Theranostics, elaborately integrating both therapeutic and diagnostic functions into a nanoplatform holds great potential for precision cancer medicine.

Methods

Herein, a biodegradable theranostic nanoplatform with hyperthermia-induced bubble ability for highly efficient ultrasound (US) imaging-guided chemo-photothermal therapy of breast tumors was developed. The prepared nanoparticles consisted of polydopamine (PDA)-modified hollow mesoporous organosilica nanoparticles (HMONs) with approximately 75 nm in diameter for doxorubicin (DOX) loading and perfluoropentane (PFP) filling. In addition, the pH-sensitive PDA coating served as both gatekeeper controlling DOX release and photothermal agent for inducing hyperthermia.

Results

Such nanoplatform (PDA@HMONs-DOX/PFP, PHDP) provides efficient loading (328 mg/g) and controllable stimuli-responsive release of DOX for chemotherapy. The incorporated disulfide bonds in the framework of HMONs endowed nanoparticles with intrinsic glutathione-responsive biodegradability and improved biocompatibility. Benefiting from the hyperthermia upon an 808-nm laser irradiation of PDA, the liquid-gas phase transition of the loaded PFP was induced, resulting in the generation of the nanobubbles, followed by the coalescence into microbubbles. This conversation could enhance the tumor cell uptake of nanoparticles, as well as intensify the US imaging signals. In addition, a synergistic therapeutic effect of our fabricated nanoplatform on cells/tumor growth effect has been systematically evaluated both in vitro and in vivo.

Conclusion

Therefore, such "all-in-one" PHDP nanoparticles with satisfactory biocompatibility and biodegradability, hyperthermia-induced bubble ability and simultaneous US imaging performance hold great potential for cancer nanotheranostics.

Mesoporous Organosilica Hollow Nanoparticles: Synthesis and Applications

Hollow periodic mesoporous organosilicas (PMOs) with molecularly homogeneous organic functional groups in the inorganic pore walls are attracting more and more attention due to the high surface areas, tunable pore sizes, low densities, large cavities in the center, permeable thin shells, and versatile organic-inorganic hybrid frameworks, which make them promising in a variety of applications including adsorption, catalysis, drug delivery, and nanotheranostics. Herein, recent advances in the synthesis of hollow PMO nanoparticles with various organic moieties are summarized, and the mechanism and new insights of synthesis approaches, including hard-core templating methods, liquid-interface assembly methods, and the interfacial reassembly and transformation strategy are discussed in-depth. Meanwhile, the design principles, properties, and synthetic strategies for some smart hollow architectures such as multishelled hollow PMOs, yolk-shell structured PMOs, and nonspherical hollow PMOs are discussed. Moreover, the typical applications of hollow PMO nanomaterials as nanoreactors for chemical transformations and nanoplatforms for biomedicine are summarized. Finally, the challenges and prospects for the future development of hollow PMOs are described.

A Multifunctional Biodegradable Nanocomposite for Cancer Theranostics

Theranostic formulations, integrating both diagnostic and therapeutic functions into a single platform, hold great potential for precision medicines. In this work, a biodegradable theranostic based on hollow mesoporous organosilica nanoparticles (HMONs) is reported and explored for ultrasound/photoacoustic dual-modality imaging guided chemo-photothermal therapy of cancer. The HMONs prepared are endowed with glutathione-responsive biodegradation behavior by incorporating disulfide bonds into their framework. The nanoparticles are loaded with indocyanine green (ICG) and perfluoropentane (PFP). The former acts as a photothermal agent and the latter can generate bubbles for ultrasound imaging. A paclitaxel prodrug is developed to both serve as a redox-sensitive gatekeeper controlling ICG release from the HMON pores and a chemotherapeutic. ICG generates mild hyperthermia upon exposure to an 808 nm laser, and this in turn leads to a liquid-gas phase transition of PFP, resulting in the generation of bubbles which can be used for ultrasound imaging. The platform is found to have excellent properties for both ultrasound and photoacoustic imaging. In addition, both in vitro and in vivo results show that the nanoparticles provide potent synergistic chemo-photothermal therapy. The material developed in this work thus has great potential for exploitation in advanced cancer therapies.

Recent Advances in Small Copper Sulfide Nanoparticles for Molecular Imaging and Tumor Therapy

Small copper sulfide nanoparticles (s-Cu_2-xS NPs, 0 < x < 1) with a core size of less than 5.5 nm have unique physicochemical characteristics and pharmacokinetic properties and have attracted substantial attention from researchers in the field of biomedicine in recent years. After exposure to near-infrared (NIR) light, s-Cu_2-xS NPs can rapidly convert light energy into heat for photoacoustic imaging (PAI) and photothermal therapy (PTT). In addition, the potential for magnetic resonance imaging (MRI) and positron emission tomography (PET) imaging, along with the low toxicity and low cost, makes s-Cu_2-xS NPs a promising multifunctional diagnostic reagent. This Review outlines recent advances in s-Cu_2-xS NPs for molecular imaging and tumor therapy and discusses the challenges associated with successful clinical translation.

Inorganic nanomaterials for chemo/photothermal therapy: a promising horizon on effective cancer treatment

During the last few decades, nanotechnology has established many essential applications in the biomedical field and in particular for cancer therapy. Not only can nanodelivery systems address the shortcomings of conventional chemotherapy such as limited stability, non-specific biodistribution and targeting, poor water solubility, low therapeutic indices, and severe toxic side effects, but some of them can also provide simultaneous combination of therapies and diagnostics. Among the various therapies, the combination of chemo- and photothermal therapy (CT-PTT) has demonstrated synergistic therapeutic efficacies with minimal side effects in several preclinical studies. In this regard, inorganic nanostructures have been of special interest for CT-PTT, owing to their high thermal conversion efficiency, application in bio-imaging, versatility, and ease of synthesis and surface modification. In addition to being used as the first type of CT-PTT agents, they also include the most novel CT-PTT systems as the potentials of new inorganic nanomaterials are being more and more discovered. Considering the variety of inorganic nanostructures introduced for CT-PTT applications, enormous effort is needed to perform translational research on the most promising nanomaterials and to comprehensively evaluate the potentials of newly introduced ones in preclinical studies. This review provides an overview of most novel strategies used to employ inorganic nanostructures for cancer CT-PTT as well as cancer imaging and discusses current challenges and future perspectives in this area.

Rapid and Highly Effective Noninvasive Disinfection by Hybrid Ag/CS@MnO2 Nanosheets Using Near-Infrared Light

A bacterial infection on the surface of medical apparatus and instruments as well as artificial implants is threatening human health greatly. Antibiotics and traditional bacterial-killing agents, even silver nanoparticles, can induce bacterial resistance during long-term interaction with bacteria. Hence, rapid surface sterilization and prevention of bacterial infection in the long term are urgent for biomedical devices, especially for artificial implant materials. Herein, a hybridized chitosan (CS), silver nanoparticles (AgNPs), and MnO₂ nanosheets coating was designed on the surface of titanium plates, which can ensure the implants a rapid and highly effective antibacterial efficacy of 99.00% against Staphylococcus aureus ( S. aureus) and 99.25% against Escherichia coli ( E. coli) within 20 min of 808 nm near-infrared light (NIR) irradiation. The exogenous NIR irradiation can trigger the MnO₂ nanosheets to produce enough hyperthermia within 10 min, which can combine with a low concentration of prereleased Ag⁺ from the coating to achieve superior antimicrobial efficacy through synergistic effects. In contrast, either prereleased Ag ions or a photothermal effect alone can achieve much lower antibacterial efficiency under the same concentration, i.e., 24.00% and 30.01% for the former and 30.00% and 42.54% for the later toward S. aureus and E. coli, respectively. The possible cytotoxicity of coatings could be eliminated owing to the low concentration of AgNPs and chitosan encapsulation. Thus, the novel bifunctional coating Ag/CS@MnO₂ can exhibit great potential in deep site disinfection of Ti implants through the synergy of prereleased Ag ions and a photothermal effect within a short time.

New insights towards mesoporous silica nanoparticles as a technological platform for chemotherapeutic drugs delivery

Mesoporous silica nanoparticles (MSNs) displays interesting properties for biomedical applications such as high chemical stability, large surface area and tunable pores diameters and volumes, allowing the incorporation of large amounts of drugs, protecting them from deactivation and degradation processes acting as an excellent nanoplatform for drug delivery. However, the functional MSNs do not present the ability to transport the therapeutics without any leakage until reach the targeted cells causing side effects. On the other hand, the hydroxyls groups available on MSNs surface allows the conjugation of specific molecules which can binds to the overexpressed Enhanced Growth Factor Receptor (EGFR) in many tumors, representing a potential strategy for the cancer treatment. Beyond that, the targeting molecules conjugate onto mesoporous surface increase its cell internalization and act as gatekeepers blocking the mesopores controlling the drug release. In this context, multifunctional MSNs emerge as stimuli-responsive controlled drug delivery systems (CDDS) to overcome drawbacks as low internalization, premature release before to reach the region of interest, several side effects and low effectiveness of the current treatments. This review presents an overview of MSNs fabrication methods and its properties that affects drug delivery as well as stimuli-responsive CDDS for cancer treatment.

Photothermal therapy and photoacoustic imaging via nanotheranostics in fighting cancer

The nonradiative conversion of light energy into heat (photothermal therapy, PTT) or sound energy (photoacoustic imaging, PAI) has been intensively investigated for the treatment and diagnosis of cancer, respectively. By taking advantage of nanocarriers, both imaging and therapeutic functions together with enhanced tumour accumulation have been thoroughly studied to improve the pre-clinical efficiency of PAI and PTT. In this review, we first summarize the development of inorganic and organic nano photothermal transduction agents (PTAs) and strategies for improving the PTT outcomes, including applying appropriate laser dosage, guiding the treatment via imaging techniques, developing PTAs with absorption in the second NIR window, increasing photothermal conversion efficiency (PCE), and also increasing the accumulation of PTAs in tumours. Second, we introduce the advantages of combining PTT with other therapies in cancer treatment. Third, the emerging applications of PAI in cancer-related research are exemplified. Finally, the perspectives and challenges of PTT and PAI for combating cancer, especially regarding their clinical translation, are discussed. We believe that PTT and PAI having noteworthy features would become promising next-generation non-invasive cancer theranostic techniques and improve our ability to combat cancers.

Copper sulfide: An emerging adaptable nanoplatform in cancer theranostics

Copper sulfide nanoparticles (CuS NPs), emerging nanoplatforms with dual diagnostic and therapeutic applications, are being actively investigated in this era of "war on cancer" owing to their versatility and adaptability. This article discusses the pros and cons of using CuS NPs in diagnostics, therapeutics, and theranostics. The first section introduces CuS NPs and discusses the features that render them more advantageous than other established nanoplatforms in cancer management. Subsequent sections include specific in vitro and in vivo results of different studies showing the potential of CuS NPs as nanoplatforms. Methods used for visualization (photoacoustic imaging and magnetic resonance imaging) of CuS NPs and treatment (phototherapy and combinatorial therapy) have also been discussed. Furthermore, the challenges and opportunities associated with using CuS NPs have been elucidated. Further investigations on CuS NPs are required to translate it for clinical applications.

Merging metal organic framework with hollow organosilica nanoparticles as a versatile nanoplatform for cancer theranostics

With great potential in nanomedicine, the integration of a metal organic framework (MOF) with a nanocarrier for smart and versatile cancer theranostics still seeks to expand. In this study, MOF was successfully merged with hollow mesoporous organosilica nanoparticles (HMONs) with a polydopamine (PDA) interlayer to form molecularly organic/inorganic hybridized nanocomposites (HMONs-PMOF). The well-defined nanostructure and favorable biocompatibility of HMONs-PMOF were demonstrated first. Doxorubicin hydrochloride (DOX) and indocyanine green (ICG) were separately loaded into the interior cavity of HMONs and the outer porous shell of MOF with high loading efficacy, respectively. The obtained dual drug-loaded nanocomposites (DI@HMONs-PMOF) displayed favorable photothermal properties and pH/NIR-triggered DOX release manner. Furthermore, in vitro cell experiments validated that HMONs-PMOF can efficiently deliver DOX into cancer cells. Upon entry into cancer cells, the photothermal effect of DI@HMONs-PMOF can induce the lysosome rupture, thereby facilitating the "lysosome escape" process and accelerating the DOX diffusion in the cytoplasm. Benefiting from the iron ion coordinated on PDA and ICG confined in MOF, magnetic resonance (MR) and photoacoustic (PA) dual-modality imaging were performed to verify the effective accumulation of DI@HMONs-PMOF at the tumor site. Interestingly, the results also suggested that the existence of ICG can cooperatively enhance the MR imaging capability of prepared nanocomposites. In addition, the significantly improved synergistic therapeutic efficacy was confirmed both in vitro and in vivo. Thus, our results indicated that the merged nanostructure of HMONs and MOF is promising for versatile cancer theranostics. STATEMENT OF SIGNIFICANCE: Metal organic framework (MOF) has recently emerged as a class of fascinating nanocarriers. The integration of MOF with other nanostructures can endow the new nanoformulation with collective functionality and synergistic performance that are not accessed from single-component nanostructure. Herein, we reported the successful merging of MOF and hollow mesoporous organosilica nanoparticles (HMONs) to form a hollow nanocontainer with a well-defined nanostructure. The large cavity of HMONs and highly porous network of MOF enable high drug loading efficacy. Moreover, the dual-modality magnetic resonance and photoacoustic imaging can be realized, which is also benefited from the merged nanostructure. Overall, we expected this paradigm could pave way for integrating MOF with other nanocarriers to achieve more diverse applications.

Melanin-like nanoparticles decorated with an autophagy-inducing peptide for efficient targeted photothermal therapy

Photothermal therapy efficiently ablates tumors via hyperthermia but inevitably induces serious side effects including thermal damage to normal tissues, inflammations and enhanced risk of tumor metastasis. In this study, we fabricated a dual peptide decorated melanin-like nanoparticle for tumor-targeted and autophagy-promoted photothermal therapy in pursuit of improved cancer treatment. The multifunctional nanoparticle was composed of dual peptide RGD- and beclin 1-modified and PEGylated melanin-like polydopamine nanoparticles. Beclin 1-derived peptide modified on the nanoparticle up-regulated autophagy in cancer cells and further sensitized the tumors to photothermal ablation. RGD decorated on the particle surface enhanced the selectivity and cellular uptake of polydopamine nanoparticles by breast cancer cells. In vivo therapeutic experiments revealed that the tumor-targeted and autophagy promotion-associated photothermal therapy efficiently regressed tumors at a low temperature around 43 °C. The study provides a novel and efficient strategy to improve the efficiency of photothermal therapy via the up-regulation of autophagy in tumor cells.

Clinical Trials of Thermosensitive Nanomaterials: An Overview

Currently, we are facing increasing demand to develop efficient systems for the detection and treatment of diseases that can realistically improve distinct aspects of healthcare in our society. Sensitive nanomaterials that respond to environmental stimuli can play an important role in this task. In this manuscript, we review the clinical trials carried out to date on thermosensitive nanomaterials, including all those clinical trials in hybrid nanomaterials that respond to other stimuli (e.g., magnetic, infrared radiation, and ultrasound). Specifically, we discuss their use in diagnosis and treatment of different diseases. At present, none of the existing trials focused on diagnosis take advantage of the thermosensitive characteristics of these nanoparticles. Indeed, almost all clinical trials consulted explore the use of Ferumoxytol as a current imaging test enhancer. However, the thermal property is being further exploited in the field of disease treatment, especially for the delivery of antitumor drugs. In this regard, ThermoDox®, based on lysolipid thermally sensitive liposome technology to encapsulate doxorubicin (DOX), is the flagship drug. In this review, we have evidenced the discrepancy existing between the number of published papers in thermosensitive nanomaterials and their clinical use, which could be due to the relative novelty of this area of research; more time is needed to validate it through clinical trials. We have no doubt that in the coming years there will be an explosion of clinical trials related to thermosensitive nanomaterials that will surely help to improve current treatments and, above all, will impact on patients' quality of life and life expectancy.

External stimulus responsive inorganic nanomaterials for cancer theranostics

Cancer is a highly intelligent system of cells, that works together with the body to thrive and subsequently overwhelm the host in order for its survival. Therefore, treatment regimens should be equally competent to outsmart these cells. Unfortunately, it is not the case with current therapeutic practices, the reason why it is still one of the most deadly adversaries and an imposing challenge to healthcare practitioners and researchers alike. With rapid nanotechnological interventions in the medical arena, the amalgamation of diagnostic and therapeutic functionalities into a single platform, theranostics provides a never before experienced hope of enhancing diagnostic accuracy and therapeutic efficiency. Additionally, the ability of these nanotheranostic agents to perform their actions on-demand, i.e. can be controlled by external stimulus such as light, magnetic field, sound waves and radiation has cemented their position as next generation anti-cancer candidates. Numerous reports exist of such stimuli-responsive theranostic nanomaterials against cancer, but few have broken through to clinical trials, let alone clinical practice. This review sheds light on the pros and cons of a few such theranostic nanomaterials, especially inorganic nanomaterials which do not require any additional chemical moieties to initiate the stimulus. The review will primarily focus on preclinical and clinical trial approved theranostic agents alone, describing their success or failure in the respective stages.

Triple-Modal Imaging-Guided Chemo-Photothermal Synergistic Therapy for Breast Cancer with Magnetically Targeted Phase-Shifted Nanoparticles

Current nanodrug-based cancer therapy is susceptible to the problems of rapid clearance from circulation and limited therapeutic efficacy. Herein, we report a magnetically targeted and photothermal-triggered drug release nanotheranostics system based on superparamagnetic iron oxide (Fe₃O₄), IR780, doxorubicin (DOX), and perfluoropentane (PFP) entrapped poly-lactide- co-glycolide (PLGA) nanoparticles (IR780/Fe₃O₄@PLGA/PFP/DOX NPs) for triple-modal imaging-guided synergistic therapy of breast cancer. In this work, IR780 and Fe₃O₄ convert light into heat, which triggers DOX release from IR780/Fe₃O₄@PLGA/PFP/DOX NPs and a phase-shift thermoelastic expansion of PFP; this procedure further accelerates the DOX release and tissue extrusion deformation. Fe₃O₄ NPs also serve as the target moiety by an external magnet directed to the tumor. Specifically, the IR780/Fe₃O₄@PLGA/PFP/DOX NPs can be used for triple-modal imaging, including near infrared fluorescence, magnetic resonance, and ultrasound. Furthermore, the antitumor therapy studies reveal the extraordinary performance of IR780/Fe₃O₄@PLGA/PFP/DOX NPs in magnetically targeted synergistic chemo-photothermal therapy of cancer. Therefore, the multifunctional IR780/Fe₃O₄@PLGA/PFP/DOX NPs guided by the magnetic field show a great potential for cancer theranostics.

Fabricating polydopamine-coated MoSe2-wrapped hollow mesoporous silica nanoplatform for controlled drug release and chemo-photothermal therapy

BACKGROUND

Integration of several types of therapeutic agents into one nanoplatform to enhance treatment efficacy is being more widely used for cancer therapy.

METHODS

Herein, a biocompatible polydopamine (PDA)-coated MoSe2-wrapped doxorubicin (DOX)-loaded hollow mesoporous silica nanoparticles (HMSNs) nanoplatform (PM@HMSNs-DOX) was fabricated for dual-sensitive drug release and chemo-photothermal therapy for enhancing the therapeutic effects on breast cancer. The HMSNs were obtained by a "structural difference-based selective etching" strategy and served as the drug carrier, exhibiting a high DOX loading capacity of 427 mg/g HMSNs-NH2, and then wrapped with PDA-coated MoSe2 layer to form PM@HMSNs-DOX. Various techniques proved the successful fabrication of the nanocomposites.

RESULTS

The formed PM@HMSNs-DOX nanocomposites exhibited good biocompatibility, good stability, and super-additive photothermal conversion efficiency due to the cooperation of MoSe2 and PDA. Simultaneously, the pH/near-infrared-responsive drug release profile was observed, which could enhance the synergistic therapeutic anticancer effect. The antitumor effects of PM@HMSNs-DOX were evaluated both in vitro and in vivo, demonstrating that the synergistic therapeutic efficacy was significantly superior to any monotherapy. Also, in vivo pharmacokinetics studies showed that PM@HMSNs-DOX had a much longer circulation time than free DOX. In addition, in vitro and in vivo toxicity studies certified that PM@HMSNs are suitable as biocompatible agents.

CONCLUSION

Our nanoplatform loaded with DOX displays pH/near-infrared-induced chemotherapy and excellent photothermal therapy, which hold great potential for cancer treatment.

Thermo-Sensitive Nanomaterials: Recent Advance in Synthesis and Biomedical Applications

Progress in nanotechnology has enabled us to open many new fronts in biomedical research by exploiting the peculiar properties of materials at the nanoscale. The thermal sensitivity of certain materials is a highly valuable property because it can be exploited in many promising applications, such as thermo-sensitive drug or gene delivery systems, thermotherapy, thermal biosensors, imaging, and diagnosis. This review focuses on recent advances in thermo-sensitive nanomaterials of interest in biomedical applications. We provide an overview of the different kinds of thermoresponsive nanomaterials, discussing their potential and the physical mechanisms behind their thermal response. We thoroughly review their applications in biomedicine and finally discuss the current challenges and future perspectives of thermal therapies.

In vivo Imaging-Guided Nanoplatform for Tumor Targeting Delivery and Combined Chemo-, Gene- and Photothermal Therapy

Currently, a large number of anti-tumor drug delivery systems have been widely used in cancer therapy. However, due to the molecular complexity and multidrug resistance of tumors, monotherapies remain suboptimal. Thus, this study aimed to develop a multifunctional theranostic nanoplatform for effective cancer therapy.

Methods: Folic acid-modified silver sulfide@mesoporous silica core-shell nanoparticle was first modified with desthiobiotin (db) on the surface, then doxorubicin (DOX) was loaded into pore. Avidin was employed as "gatekeeper" to prevent leakage of DOX via desthiobiotin-avidin interaction. Db-modified survivin antisense oligonucleotide (db-DNA) which could inhibit survivin expression was then grafted on avidin at the outer layer of nanoparticle. DOX release and db-DNA dissociation were simultaneously triggered by overexpressing biotin in cancer cells, then combining PTT from Ag₂S QD to inhibit tumor growth.

Results: This nanoprobe had satisfactory stability and photothermal conversion efficiency up to 33.86% which was suitable for PTT. Due to the good targeting ability and fluorescent anti-bleaching, its signal still existed at the tumor site after tail vein injection of probe into HeLa tumor-bearing nude mice for 48 h. In vitro and in vivo antitumor experiments both demonstrated that drug, gene and photothermal synergistic therapy significantly enhanced antitumor efficacy with minimal systemic toxicity.

Conclusion: Our findings demonstrate that this novel nanoplatform for targeted image-guided treatment of tumor and tactfully integrated chemotherapy, photothermal therapy (PTT) and gene therapy might provide an insight for cancer theranostics.

Targeted Theranostic Nanoparticles for Brain Tumor Treatment

The poor prognosis and rapid recurrence of glioblastoma (GB) are associated to its fast-growing process and invasive nature, which make difficult the complete removal of the cancer infiltrated tissues. Additionally, GB heterogeneity within and between patients demands a patient-focused method of treatment. Thus, the implementation of nanotechnology is an attractive approach considering all anatomic issues of GB, since it will potentially improve brain drug distribution, due to the interaction between the blood⁻brain barrier and nanoparticles (NPs). In recent years, theranostic techniques have also been proposed and regarded as promising. NPs are advantageous for this application, due to their respective size, easy surface modification and versatility to integrate multiple functional components in one system. The design of nanoparticles focused on therapeutic and diagnostic applications has increased exponentially for the treatment of cancer. This dual approach helps to understand the location of the tumor tissue, the biodistribution of nanoparticles, the progress and efficacy of the treatment, and is highly useful for personalized medicine-based therapeutic interventions. To improve theranostic approaches, different active strategies can be used to modulate the surface of the nanotheranostic particle, including surface markers, proteins, drugs or genes, and take advantage of the characteristics of the microenvironment using stimuli responsive triggers. This review focuses on the different strategies to improve the GB treatment, describing some cell surface markers and their ligands, and reports some strategies, and their efficacy, used in the current research.

Graphene quantum dots-gated hollow mesoporous carbon nanoplatform for targeting drug delivery and synergistic chemo-photothermal therapy

BACKGROUND

Carbon-based drug delivery systems have attracted great interest because of their excellent photothermal conversion capability and high specific surface area for drug loading. Herein, we report a multifunctional nanoplatform based on hyaluronic acid (HA)-modified and graphene quantum dot (GQD)-gated hollow mesoporous carbon nanoparticle (HMCN) for anticancer drug encapsulation and targeted chemo-photothermal therapy of CD44 receptor-overexpressed cancer cells.

METHODS

In this design, HMCN was not only used as a nanocarrier with high drug loading content to achieve chemotherapy, but also as a near-infrared absorbing agent to realize photothermal therapy. GQDs could not only prevent premature drug release during blood circulation, but also enhance the chemo-photothermal therapeutic efficacy for complete tumor growth suppression. After being modified with HA, the HA-HMCN(DOX)@GQDs could specifically target cancer cells.

RESULTS

As expected, the as-prepared HMCN exhibited high doxorubicin (DOX)-loading capacity of 410 mg/g and excellent light-to-heat conversion property. The DOX was released from HA-HMCN(DOX)@GQDs in a near-infrared laser and pH stimuli-responsive manner, which could enhance the therapeutic effect. In vitro cell biological experimental results confirmed that the nanoplatform possesses excellent biocompatibility, specifically target CD44 receptor-overexpressing human cervical carcinoma HeLa cells, and has remarkable synergistic chemo-photothermal killing capacity. The in vivo therapeutic studies in HeLa xenografts also showed negligible toxicity of HA-HMCN@GQDs and complete inhibition of tumor growth of HA-HMCN(DOX) @GQDs with near-infrared irradiation.

CONCLUSION

The excellent therapeutic effects demonstrated in vitro and in vivo suggested the HMCN-based nanoplatform holds potential for efficient dual-responsive targeting drug delivery and synergistic chemo-photothermal therapy.

Biodegradable Silica-Based Nanoparticles: Dissolution Kinetics and Selective Bond Cleavage

Silica-based nanomaterials are extensively used in industrial applications and academic biomedical research, thus properly assessing their toxicity and biodegradability is essential for their safe and effective formulation and use. Unfortunately, there is often a lot of confusion in the literature with respect to the toxicity and biodegradability of silica since various studies have yielded contradictory results. In this contribution, we first endeavor to underscore that the simplistic model of silica should be discarded in favor of a more realistic model recognizing that all silicas are not created equal and should thus be considered in the plural as silicas and silica hybrids, which indeed hold various biocompatibility and biodegradability profiles. We then demonstrated that all silicas are-as displayed in Nature-degradable in water by dissolution, as governed by the laws of kinetics. Lastly, we explore the vast potential of tuning the degradability of silica by materials design using various silica hybrids for redox-, pH-, enzymatic-, and biochelation-mediated lysis mechanisms.

Multifunctional melanin-like nanoparticles for bone-targeted chemo-photothermal therapy of malignant bone tumors and osteolysis

Malignant bone tumors associated with aggressive osteolysis are currently hard to be cured by the clinical strategies. Nevertheless, nanomedicine might provide a promising therapeutic opportunity. Here, we developed a multifunctional melanin-like nanoparticle for bone-targeted chemo-photothermal treatment of malignant bone tumors. The particle was originally fabricated from alendronate-conjugated polydopamine nanoparticle (PDA-ALN) that exhibited excellent photothermal effect and high affinity to hydroxyapatite. PDA/Fe-ALN significantly enhanced the magnetic resonance contrast of the bone tumors in vivo, suggesting that more PDA-ALN accumulated at the osteolytic bone lesions in the tumors compared with the non-targeting PDA. Chemodrug SN38 was efficiently loaded on PDA-ALN, and the drug release could be triggered by near-infrared irradiation and acidic stimulus. Finally, the combined chemo-photothermal therapy efficiently suppressed the growth of bone tumors and reduced the osteolytic damage of bones at a mild temperature around 43 °C. This study provides an efficient and robust nanotherapeutics for the treatment of malignant bone tumors.

Fabrication of multifunctional triple-responsive platform based on CuS-capped periodic mesoporous organosilica nanoparticles for chemo-photothermal therapy

INTRODUCTION

For an ideal drug delivery system, the outstanding drug-loading capacity and specific control of the release of therapeutics at the desired lesions are crucial. In this work, we developed a triple-responsive nanoplatform based on copper sulfide (CuS)-capped yolk-shell-structured periodic mesoporous organosilica nanoparticles (YSPMOs) for synergetic chemo-photothermal therapy.

METHODS

Herein, the YSPMOs were employed as a drug carrier, which exhibited a high doxorubicin (DOX) loading capacity of 386 mg/g. In this controlled-release drug delivery system, CuS serves as a gatekeeper to modify YSPMOs with reduction-cleavable disulfide bond (YSPMOs@CuS). CuS could not only avoid premature leakage in the delivery process, but also endowed the excellent photothermal therapy (PTT) ability.

RESULTS

Upon entering into cancer cells, the CuS gatekeeper was opened with the breaking of disulfide bonds and the DOX release from YSPMOs(DOX)@CuS in response to the intracellular acidic environment and external laser irradiation. Such a precise control over drug release, combined with the photothermal effect of CuS nanoparticles, is possessed by synergistic chemo-photothermal therapy for cancer treatment. Both in vitro and in vivo experimental data indicated that the synergistic effect of YSPMOs(DOX)@CuS showed efficient antitumor effect. In addition, low systemic toxicity was observed in the pathologic examinations of liver, spleen, lungs, and kidneys.

CONCLUSION

This versatile nanoplatform combination of PTT, chemotherapeutics, and gating components shows general potential for designing multifunctional drug delivery systems.

Hollow Mesoporous Silica@Zeolitic Imidazolate Framework Capsules and Their Applications for Gentamicin Delivery

We have synthesized hollow mesoporous silica (HMS) at a zeolitic imidazolate framework (ZIF) capsule that can be used as a drug delivery system for gentamicin (GM). The GM is first loaded into HMS. Then, the outer surface of the GM/HMS is coated with uniformed ZIF nanoparticles (denoted as GM/HMS@ZIF). The GM/HMS@ZIF has been successfully prepared and acts as a capsule for GM. The GM/HMS@ZIF shows a good biocompatibility and a good cellular uptake in House Ear Institute-Organ of Corti 1 (HEI-OC1) cells. The GM is released slowly within 10 h under acidic conditions, which is used to simulate the pH of the endosome and lysosome compartments. The in vivo assay shows that the signal from fluorescein isothiocyanate (FITC) can be observed after 15 days, when the mice were injected with FITC/HMS@ZIF. This opens new opportunities to construct a delivery system for GM via one controlled low dose and sustained release for the therapy of Ménière's disease.

Clavanin A-bioconjugated Fe3O4/Silane core-shell nanoparticles for thermal ablation of bacterial biofilms

The use of central venous catheters (CVC) is highly associated with nosocomial blood infections and its use largely requires a systematic assessment of benefits and risks. Bacterial contamination of these tubes is frequent and may result in development of microbial consortia also known as biofilm. The woven nature of biofilm provides a practical defense against antimicrobial agents, facilitating bacterial dissemination through the patient's body and development of antimicrobial resistance. In this work, the authors describe the modification of CVC tubing by immobilizing Fe₃O₄-aminosilane core-shell nanoparticles functionalized with antimicrobial peptide clavanin A (clavA) as an antimicrobial prophylactic towards Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae. Its anti-biofilm-attachment characteristic relies in clavA natural activity to disrupt the bacterial lipidic membrane. The aminosilane shell prevents iron leaching, which is an important nutrient for bacterial growth. Fe₃O₄-clavA-modified CVCs showed to decrease Gram-negative bacteria attachment up to 90% when compared to control clean CVC. Additionally, when hyperthermal treatment is triggered for 5 min at 80 °C in a tubing that already presents bacterial biofilm (CVC-BF), the viability of attached bacteria reduces up to 88%, providing an efficient solution to avoid changing catheter.

Fabrication of ultrasmall WS2 quantum dots-coated periodic mesoporous organosilica nanoparticles for intracellular drug delivery and synergistic chemo-photothermal therapy

Introduction

The consolidation of different therapies into a single nanoplatform has shown great promise for synergistic tumor treatment. In this study, a multifunctional platform by WS₂ quantum dots (WQDs)-coated doxorubicin (DOX)-loaded periodic mesoporous organosilicas (PMOs-DOX@WQDs) nanoparticles were fabricated for the first time, and which exhibits good potential for synergistic chemo-photothermal therapy.

Materials and methods

The structure, light-mediated drug release behavior, photothermal effect, and synergistic therapeutic efficiency of PMOs-DOX@WQDs to HCT-116 colon cancer cells were investigated. The thioether-bridged PMOs exhibit a high DOX loading capacity of 66.7 μg mg⁻¹. The gating of the PMOs not only improve the drug loading capacity but also introduce the dual-stimuli-responsive performance. Furthermore, the as-synthesized PMOs-DOX@WQDs nanoparticles can efficiently generate heat to the hyperthermia temperature with near infrared laser irradiation.

Results

It was confirmed that PMOs-DOX@WQDs exhibit remarkable photothermal effect and light-triggered faster release of DOX. More importantly, it was reasonable to attribute the efficient anti-tumor efficiency of PMOs-DOX@WQDs.

Conclusion

The in vitro experimental results confirm that the fabricated nanocarrier exhibits a significant synergistic effect, resulting in a higher efficacy to kill cancer cells. Therefore, the WQD-coated PMOs present promising applications in cancer therapy.

Radiolabeling Silica-Based Nanoparticles via Coordination Chemistry: Basic Principles, Strategies, and Applications

As one of the most biocompatible and well-tolerated inorganic nanomaterials, silica-based nanoparticles (SiNPs) have received extensive attention over the last several decades. Recently, positron emission tomography (PET) imaging of radiolabeled SiNPs has provided a highly sensitive, noninvasive, and quantitative readout of the organ/tissue distribution, pharmacokinetics, and tumor targeting efficiency in vivo, which can greatly expedite the clinical translation of these promising NPs. Encouraged by the successful PET imaging of patients with metastatic melanoma using ¹²⁴I-labeled ultrasmall SiNPs (known as Cornell dots or C dots) and their approval as an Investigational New Drug (IND) by the United States Food and Drug Administration, different radioisotopes (⁶⁴Cu, ⁸⁹Zr, ¹⁸F, ⁶⁸Ga, ¹²⁴I, etc.) have been reported to radiolabel a wide variety of SiNPs-based nanostructures, including dense silica (dSiO₂), mesoporous silica (MSN), biodegradable mesoporous silica (bMSN), and hollow mesoporous silica nanoparticles (HMSN). With in-depth knowledge of coordination chemistry, abundant silanol groups (-Si-O-) on the silica surface or inside mesoporous channels not only can be directly used for chelator-free radiolabeling but also can be readily modified with the right chelators for chelator-based labeling. However, integrating these labeling strategies for constructing stably radiolabeled SiNPs with high efficiency has proven difficult because of the complexity of the involved key parameters, such as the choice of radioisotopes and chelators, nanostructures, and radiolabeling strategy. In this Account, we present an overview of recent progress in the development of radiolabeled SiNPs for cancer theranostics in the hope of speeding up their biomedical applications and potential translation into the clinic. We first introduce the basic principles and mechanisms for radiolabeling SiNPs via coordination chemistry, including general rules of selecting proper radioisotopes, engineering silica nanoplatforms (e.g., dSiO₂, MSN, HMSN) accordingly, and chelation strategies for enhanced labeling efficiency and stability, on which our group has focused over the past decade. Generally, the medical applications guide the choice of specific SiNPs for radiolabeling by considering the inherent functionality of SiNPs. The radioisotopes can then be determined according to the amenability of the particular SiNPs for chelator-based or chelator-free radiolabeling to obtain high labeling stability in vivo, which is a prerequisite for PET to truly reflect the behavior of SiNPs since PET imaging detects the isotopes rather than nanoparticles. Next, we highlight several recent representative biomedical applications of radiolabeled SiNPs including molecular imaging to detect specific lesions, PET-guided drug delivery, SiNP-based theranostic cancer agents, and clinical studies. Finally, the challenges and prospects of radiolabeled SiNPs are briefly discussed toward clinical cancer research. We hope that this Account will clarify the recent progress on the radiolabeling of SiNPs for specific medical applications and generate broad interest in integrating nanotechnology and PET imaging. With several ongoing clinical trials, radiolabeled SiNPs offer great potential for future patient stratification and cancer management in clinical settings.

Biodegradable Hollow Mesoporous Organosilica Nanotheranostics for Mild Hyperthermia-Induced Bubble-Enhanced Oxygen-Sensitized Radiotherapy

Alleviation of tumor hypoxia has been the premise for improving the effectiveness of radiotherapy, which hinges upon the advanced delivery and rapid release of oxygen within the tumor region. Herein, we propose a "bubble-enhanced oxygen diffusion" strategy to achieve whole tumor oxygenation for significant radiation enhancement based on the "bystander effect". Toward this end, sub-50 nm CuS-modified and ⁶⁴Cu-labeled hollow mesoporous organosilica nanoparticles were constructed for tumor-specific delivery of O₂-saturated perfluoropentane (PFP). Through the aid of PFP gasification arising from NIR laser-triggered mild hyperthermia, simultaneous PET/PA/US multimodality imaging and rapid oxygen diffusion across the tumor can be achieved for remarkable hypoxic radiosensitization. Furthermore, the multifunctional oxygen-carrying nanotheranostics also allow for other oxygen-dependent treatments, thus greatly advancing the development of bubble-enhanced synergistic therapy platforms.

Se@SiO2-FA-CuS nanocomposites for targeted delivery of DOX and nano selenium in synergistic combination of chemo-photothermal therapy

In this study, a versatile tumor-targeted and multi-stimuli-responsive drug delivery vehicle (Se particle@porous silica-folic acid-copper sulfide/doxorubicin (Se@SiO₂-FA-CuS/DOX)) was fabricated for combined photothermal therapy with chemotherapy in cancer treatment. Due to excellent targeting ability, the Se@SiO₂-FA-CuS/DOX nanocomposites actively accumulated in tumor tissues and thus provided photothermal therapy under NIR irradiation and chemotherapy through the release of DOX and Se. Owing to the synergistic effect of chemotherapy (Se and DOX) and photothermal therapy, the Se@SiO₂-FA-CuS/DOX nanocomposites could efficiently inhibit cancer cells both in vitro and in vivo and even completely eliminate tumors. Moreover, as the toxicity of DOX could be reduced by Se, the treatment using Se@SiO₂-FA-CuS/DOX nanocomposites exhibited no appreciable adverse reactions. Thus, the Se@SiO₂-FA-CuS/DOX nanocomposites have great potential as a multifunctional nanoplatform in future clinical applications.

Light-Responsive Biodegradable Nanorattles for Cancer Theranostics

Cancer nanotheranostics, integrating both diagnostic and therapeutic functions into nanoscale agents, are advanced solutions for cancer management. Herein, a light-responsive biodegradable nanorattle-based perfluoropentane-(PFP)-filled mesoporous-silica-film-coated gold nanorod (GNR@SiO₂ -PFP) is strategically designed and prepared for enhanced ultrasound (US)/photoacoustic (PA) dual-modality imaging guided photothermal therapy of melanoma. The as-prepared nanorattles are composed of a thin mesoporous silica film as the shell, which endows the nanoplatform with flexible morphology and excellent biodegradability, as well as large cavity for PFP filling. Upon 808 nm laser irradiation, the loaded PFP will undergo a liquid-gas phase transition due to the heat generation from GNRs, thus generating nanobubbles followed by the coalescence into microbubbles. The conversion of nanobubbles to microbubbles can improve the intratumoral permeation and retention in nonmicrovascular tissue, as well as enhance the tumor-targeted US imaging signals. This nanotheranostic platform exhibits excellent biocompatibility and biodegradability, distinct gas bubbling phenomenon, good US/PA imaging contrast, and remarkable photothermal efficiency. The results demonstrate that the GNR@SiO₂ -PFP nanorattles hold great potential for cancer nanotheranostics.