CpG loaded MoS2 nanosheets as multifunctional agents for photothermal enhanced cancer immunotherapy

Folin-Ciocalteu Assay Inspired Polyoxometalate Nanoclusters as a Renal Clearable Agent for Non-Inflammatory Photothermal Cancer Therapy

Similar to translated thermal ablative techniques in clinic, the occurrence of cellular necrosis during tumor photothermal therapy (PTT) would induce inflammatory responses that are detrimental to therapeutic outcomes. Inspired by the well-known colorimetric Folin-Ciocalteu assay, monodispersed and renal-clearable tungsten (W)-based polyoxometalate nanoclusters (W-POM NCs, average diameter of around 2.0 nm) were successfully obtained here through a facile redox reaction with natural gallic acid in alkaline aqueous solution. Apart from excellent stability in the form of freeze-dried powder, the as-prepared W-POM NCs occupied considerable biocompatibility toward normal cells/tissues both in vitro and in vivo, since no obvious toxicities were observed by treating female Balb/c mice with concentrated W-POM NCs during the 30 day post-treatment period. More importantly, W-POM NCs exhibited not only considerable near-infrared (NIR) light absorption (coloration effect originated from the existence of electron-trapped W⁵⁺) for efficient PTT but also impressive anti-inflammatory ability (eliminating inflammation-related reactive oxygen species by the oxidation of W⁵⁺ into W⁶⁺ state) to achieve better therapeutic outcomes. Thus, our study pioneers the application of POMs for non-inflammatory PTT with expected safety and efficiency.

A trustworthy CpG nanoplatform for highly safe and efficient cancer photothermal combined immunotherapy

Palladium nanosheets (Pd NSs) have recently attracted increasing research interest in the biomedical field due to their excellent near-infrared absorption, photothermal conversion capability and biocompatibility. However, the application of Pd NSs in immunotherapy has not been reported. Here, Pd NSs were used as the carriers of immunoadjuvant CpG ODNs for not only efficient delivery of CpG but also for enhancing the immunotherapeutic effects of CpG by the Pd NS-based photothermal therapy (PTT). Pd NSs had no influence on the immune system, and the prepared Pd-CpG nanocomposites, especially Pd(5)-CpG(PS), could significantly increase the uptake of CpG by immune cells and enhance the immunostimulatory activity of CpG in vitro and in vivo. With the combination of Pd(5)-CpG(PS) mediated PTT and immunotherapy, highly efficient tumor inhibition was achieved and the survival rate of the tumor-bearing mice was greatly increased depending on Pd(5)-CpG(PS) with safe near-infrared (NIR) irradiation (808 nm laser, 0.15 W cm^-2). Importantly, the combination therapy induced tumor cell death and released tumor-associated antigens, which could be effectively taken up and presented by antigen presenting cells with the assistance of CpG, leading to increased TNF-α and IL-6 production and enhanced cytotoxic T lymphocyte (CTL) activity. This work provides a new paradigm of utilizing photothermal nanomaterials for safe and highly efficient cancer photothermal combined immunotherapy.

Modulation of tumor microenvironment for immunotherapy: focus on nanomaterial-based strategies

Recent advances in the field of immunotherapy have profoundly opened up the potential for improved cancer therapy and reduced side effects. However, the tumor microenvironment (TME) is highly immunosuppressive, therefore, clinical outcomes of currently available cancer immunotherapy are still poor. Recently, nanomaterial-based strategies have been developed to modulate the TME for robust immunotherapeutic responses. In this review, the immunoregulatory cell types (cells relating to the regulation of immune responses) inside the TME in terms of stimulatory and suppressive roles are described, and the technologies used to identify and quantify these cells are provided. In addition, recent examples of nanomaterial-based cancer immunotherapy are discussed, with particular emphasis on those designed to overcome barriers caused by the complexity and diversity of TME.

Adoptive cellular immunotherapy of tumors via effective CpG delivery to dendritic cells using dendrimer-entrapped gold nanoparticles as a gene vector

PEGylated Au DENPs ({(Au⁰)₂₅-G5·NH₂-mPEG₂₀}) are synthesized and used as a novel nonviral vector to deliver CpG to mature BMDCs for the subsequent activation of T cells for adoptive tumor immunotherapy.

2D nanostructures beyond graphene: preparation, biocompatibility and biodegradation behaviors

The research advances of the preparation, biocompatibility and biodegradation of 2D nanomaterials are introduced. The prospects and challenges of the biomedical applications of 2D nanomaterials are summarized.

Silk Fibroin for CpG Oligodeoxynucleotide Delivery

CpG oligodeoxynucleotides (ODNs) have attracted increasing attention as immunotherapeutic agents. However, efficient transfection of CpG ODNs into the immune cells remains a big challenge. In this study, for the first time, we reported that silk fibroin (SF) could function as an efficient carrier for CpG ODNs. A novel strategy was developed to prepare SF-CpG ODNs nanoparticles (NPs) based on self-assembly of SF. The as-prepared SF-CpG NPs were spherical in shape and were uniformly dispersed. SF-CpG NPs exhibited good stability and biocompatibility. SF-CpG NPs possessed significantly enhanced (7 folds) cellular uptake compared with CpG ODNs. Release of CpG ODNs from SF-CpG NPs was accelerated in environment-mimicking TLR9-localized endo/lysosome. SF-CpG NPs stimulated about four folds higher levels of immune cytokines and nitric oxide compared with CpG ODNs. Our results suggested that SF notably improved the CpG ODNs delivery. SF-CpG NPs have strong potential in immunotherapy.

Functional Layered Double Hydroxide Nanohybrids for Biomedical Imaging

Biomedical investigations using layered double hydroxide (LDH) nanoparticles have attracted tremendous attentions due to their advantages such as biocompatibility, variable-chemical compositions, anion-exchange capacity, host-guest interactions, and crystallization-dissolution characters. Bio-imaging becomes more and more important since it allows theranostics to combine therapy and diagnosis, which is a concept of next-generation medicine. Based on the unique features mentioned above, LDHs create novel opportunities for bio-imaging and simultaneous therapy with LDHs-based nanohybrids. This review aims to explore the recent advances in multifunctional LDH nanohybrids ranging from synthesis to practical applications for various bio-imaging with therapeutic functions. Furthermore, their potential both as diagnostic agents and drug delivery carriers will be discussed with the improvement in noninvasive bio-imaging techniques.

Multifunctional two-dimensional nanocomposites for photothermal-based combined cancer therapy

Two-dimensional (2D) nanocomposites have been widely used in biomedical applications during the past few years due to their extraordinary physicochemical properties, which has proved their importance in the field of nanomedicine. Benefiting from the excellent optical absorption in the near-infrared window and large specific surface area, many efforts have been devoted to fabricating 2D nanomaterial-based multifunctional nanoplatforms to realize photothermal therapy (PTT)-based or chemotherapy-based synergistic treatment, which exhibits obvious anti-tumor effects and significantly enhances the therapeutic efficiency of cancer compared with monotherapy. In particular, 2D nanocomposites are usually fabricated as intelligent nanoplatforms for stimuli-responsive nanocarriers, whose therapeutic effects could be specifically activated by the tumor microenvironment (TME). In addition, different fluorescent probes and functional inorganic nanomaterials could be absorbed on the surface of 2D nanomaterials to fabricate multifunctional hybrid nanomaterials with satisfactory magnetic, optical, or other properties that are widely used for multimodal imaging-guided cancer therapy. In this review, the latest development of multifunctional 2D nanocomposites for combination therapy is systematically summarized, mainly focusing on PTT-based synergistic cancer therapy, and the other forms and potential forms of synergistic cancer therapy are also simply summarized. Furthermore, the design principles of 2D nanocomposites are particularly emphasized, and the current challenges and future prospects of 2D nanocomposites for cancer theranostics are discussed simultaneously.

Prussian blue nanoparticle-based antigenicity and adjuvanticity trigger robust antitumor immune responses against neuroblastoma

We describe the synthesis of CpG oligodeoxynucleotide-coated Prussian blue nanoparticles (CpG-PBNPs) that function as a nanoimmunotherapy for neuroblastoma, a common childhood cancer. These CpG-PBNPs increase the antigenicity and adjuvanticity of the treated tumors, ultimately driving robust antitumor immunity through a multi-pronged mechanism. CpG-PBNPs are synthesized using a facile layer-by-layer coating scheme resulting in nanoparticles that exhibit monodisperse size distributions and multiday stability without cytotoxicity. The strong intrinsic absorption of PBNPs in the CpG-PBNPs enables ablative photothermal therapy (CpG-PBNP-PTT) that triggers tumor cell death, as well as the release of tumor antigens to increase antigenicity. Simultaneously, the CpG coating functions as an exogenous molecular adjuvant that complements the endogenous adjuvants released by the CpG-PBNP-PTT (e.g. ATP, calreticulin, and HMGB1). In cell culture, coating NPs with CpG increases immunogenicity while maintaining the photothermal activity of PBNPs. When administered in a syngeneic, Neuro2a-based, murine model of neuroblastoma, CpG-PBNP-PTT results in complete tumor regression in a significantly higher proportion (70% at 60 days) of treated animals relative to controls. Furthermore, the long-term surviving, CpG-PBNP-PTT-treated animals reject Neuro2a rechallenge, suggesting that this therapy generates immunological memory. Our findings point to the importance of simultaneous cytotoxicity, antigenicity, and adjuvanticity to generate robust and persistent antitumor immune responses against neuroblastoma.

Nanoparticle-Mediated Immunogenic Cell Death Enables and Potentiates Cancer Immunotherapy

Cancer immunotherapies that train or stimulate the inherent immunological systems to recognize, attack, and eradicate tumor cells with minimal damage to healthy cells have demonstrated promising clinical responses in recent years. However, most of these immunotherapeutic strategies only benefit a small subset of patients and cause systemic autoimmune side effects in some patients. Immunogenic cell death (ICD)-inducing modalities not only directly kill cancer cells but also induce antitumor immune responses against a broad spectrum of solid tumors. Such strategies for generating vaccine-like functions could be used to stimulate a "cold" tumor microenvironment to become an immunogenic, "hot" tumor microenvironment, working in synergy with immunotherapies to increase patient response rates and lead to successful treatment outcomes. This Minireview will focus on nanoparticle-based treatment modalities that can induce and enhance ICD to potentiate cancer immunotherapy.

2D MoS2 -Based Nanomaterials for Therapeutic, Bioimaging, and Biosensing Applications

Molybdenum disulfide (MoS₂ ), a typical layered 2D transition metal dichalcogenide, has received colossal interest in the past few years due to its unique structural, physicochemical, optical, and biological properties. While MoS₂ is mostly applied in traditional industries such as dry lubricants, intercalation agents, and negative electrode material in lithium-ion batteries, its 2D and 0D forms have led to diverse applications in sensing, catalysis, therapy, and imaging. Herein, a systematic overview of the progress that is made in the field of MoS₂ research with an emphasis on its different biomedical applications is presented. This article provides a general discussion on the basic structure and property of MoS₂ and gives a detailed description of its different morphologies that are synthesized so far, namely, nanosheets, nanotubes, and quantum dots along with synthesis strategies. The biomedical applications of MoS₂ -based nanocomposites are also described in detail and categorically, such as in varied therapeutic and diagnostic modalities like drug delivery, gene delivery, phototherapy, combined therapy, bioimaging, theranostics, and biosensing. Finally, a brief commentary on the current challenges and limitations being faced is provided, along with a discussion of some future perspectives for the overall improvement of MoS₂ -based nanocomposites as a potential nanomedicine.

Recent advances in nanomaterial-based synergistic combination cancer immunotherapy

This review aims to summarize various synergistic combination cancer immunotherapy strategies based on nanomaterials.

Local biomaterials-assisted cancer immunotherapy to trigger systemic antitumor responses

Cancer immunotherapy by educating or stimulating patients’ own immune systems to attack cancer cells has demonstrated promising therapeutic responses in the clinic.

An "all-in-one" antitumor and anti-recurrence/metastasis nanomedicine with multi-drug co-loading and burst drug release for multi-modality therapy

Drug-loading often suffers from tedious procedures, limited loading efficiency, slow release, and therefore a low curative effect. Cancer easily recurs and metastasizes even after a solid tumor is removed. Herein, we report a simple strategy with multi-drug co-loading and burst drug release for a high curative effect and anti-recurrence/metastasis. CuS nanoparticles, protoporphyrin IX, and doxorubicin were added to the precursors of ZIF-8 with one-pot co-loading during the formation of ZIF-8 for chemo-, photothermal-, and photodynamic-therapy to eliminate solid tumors. Negative CpG, as a kind of immune adjuvant, was adsorbed on the positive surface of ZIF-8 to inhibit the recurrence and metastasis of tumors with its long-term immune response. Precision treatment with one-pot multi-drug co-loading, controllable drug delivery, and multi-modality therapy may be anticipated by this versatile strategy.

Recent advances in the field of transition metal dichalcogenides for biomedical applications

Nanosheets of transition metal dichalcogenide (TMDs), the graphene-like two-dimensional (2D) materials, exhibit a unique combination of properties and have attracted enormous research interest for a wide range of applications including catalysis, functional electronics, solid lubrication, photovoltaics, energy materials and most recently in biomedical applications. Their potential for use in biosensors, drug delivery, multimodal imaging, antimicrobial agents and tissue engineering is being actively studied. However, the commercial translation of exfoliated TMDs has been limited due to the low aqueous solubility, non-uniformity, lack of control over the layer thickness, and the long-term colloidal stability of the exfoliated material. There is wide interest in the synthesis and exfoliation of TMDs resulting in the reporting of increasing numbers of new methods and their biomedical applications. The unique physicochemical characteristics of the TMD nanosheets have been exploited to tether them with biological payload to achieve selective localized delivery in vivo. The large surface-to-volume ratio, good cytocompatibility, ease of surface modification, tunable bandgap, strong spin-orbit coupling, and high optical and thermal conversion efficiency of TMD nanosheets make them favorable over traditional nanomaterials for biomedical research. Moreover, the presence of abundant active edge sites on the 2D TMDs makes them suitable for catalytic activities, while the large surface area and the interspace between layers are particularly conducive to ion or small molecule intercalation, making them useful for energy storage applications with rapid redox reaction capabilities. One of the major limitations of the exfoliated TMDs has been their limited colloidal stability in aqueous media. In this review, we summarize the recent advances in the exfoliation and synthesis of single-layered TMDs, their biomedical efficacy in terms of cytotoxicity, combinatorial therapy and diagnostic imaging, as well as antimicrobial activity. We highlight the current challenges in the field and propose strategies for the future.

Laser Immunotherapy in Combination with Perdurable PD-1 Blocking for the Treatment of Metastatic Tumors

A convenient and feasible therapeutic strategy for malignant and metastatic tumors was constructed here by combining photothermal ablation (PTA)-based laser immunotherapy with perdurable PD-1 blockade immunotherapy. Hollow gold nanoshells (HAuNS, a photothermal agent) and AUNP12 (an anti PD-1 peptide, APP) were co-encapsulated into poly(lactic- co-glycolic) acid (PLGA) nanoparticles. Unlike monoclonal PD-1/PD-L1 antibodies, PD-1 peptide inhibitor shows lower cost and immunotoxicity but needs frequent administration due to its rapid clearance in vivo. Our data here showed that the formed HAuNS- and APP-loaded PLGA nanoparticles (AA@PN) could maintain release periods of up to 40 days for the peptide, and a single intratumoral injection of AA@PN could replace the frequent administration of free APP. After the administration of AA@PN and irradiation with a near-infrared laser at the tumor site, an excellent killing effect on the primary tumor cells was achieved by the PTA. The nanoparticles also played a vaccine-like role under the adjuvant of cytosine-phospho-guanine (CpG) oligodeoxynucleotide and generated a localized antitumor-immune response. Furthermore, sustained APP release with laser-dependent transient triggering could induce the blockage of PD-1/PD-L1 pathway to activate T cells, thus subsequently generating a systemic immune response. Our data demonstrated that the PTA combined with perdurable PD-1 blocking could efficiently eradicate the primary tumors and inhibit the growth of metastatic tumors as well as their formation. The present study provides a promising therapeutic strategy for the treatment of advanced cancer with metastasis and presents a valuable reference for obtaining better outcomes in clinical cancer immunotherapy.

Influences of nanocarrier morphology on therapeutic immunomodulation

Nanomaterials provide numerous advantages for the administration of therapeutics, particularly as carriers of immunomodulatory agents targeting specific immune cell populations during immunotherapy. While the physicochemical characteristics of nanocarriers have long been linked to their therapeutic efficacy and applications, focus has primarily been placed on assessing influences of size and surface chemistry. In addition to these materials properties, the nanostructure morphology, in other words, shape and aspect ratio, has emerged as an equally important feature of nanocarriers that can dictate mechanisms of endocytosis, biodistribution and degree of cytotoxicity. In this review, we will highlight how the morphological features of nanostructures influence the immune responses elicited during therapeutic immunomodulation.

BN nanospheres functionalized with mesoporous silica for enhancing CpG oligodeoxynucleotide-mediated cancer immunotherapy

CpG oligodeoxynucleotides (CpG ODNs) possess strong immunostimulatory activity, which hold great promise in cancer immunotherapy. However, their therapeutic efficacy is largely limited due to nuclease degradation and poor cellular internalization. Efficiently delivering CpG ODNs into target cells is crucial to improve their therapeutic efficacy. Boron nitride nanospheres (BNNS) possess advantage as carriers for CpG ODNs. However, their poor aqueous dispersity and low CpG ODN loading capacity became a big obstacle for further applications. Herein, we develop amino group grafted, mesoporous silica (MS)-functionalized BNNS as novel nanovectors for CpG ODN delivery. Modification of BNNS with MS significantly improved the dispersity of BNNS and CpG ODN loading. BNNS@MS-NH2 exhibited no cytotoxicity and enhanced the delivery of CpG ODNs into macrophages. BNNS@MS-NH2/CpG ODN complexes triggered enhanced immunostimulation and induced higher amounts of cytokines. Most importantly, BNNS@MS-NH2/CpG ODN complexes induced bifurcated cytokines, which simultaneously simulated the secretion of IL-6, TNF-α and IFN-α. In contrast, CpG ODN and BNNS/CpG ODN complexes could not. The result of the Transwell plate assay suggested that BNNS@MS-NH2/CpG ODN complexes were more effective in inhibiting cancer cell growth. Taken together, our findings provide a promising strategy for enhancing CpG ODN-mediated cancer immunotherapy.

Near-infrared laser mediated modulation of ice crystallization by two-dimensional nanosheets enables high-survival recovery of biological cells from cryogenic temperatures

Two-dimensional (2D) graphene oxide (GO) and molybdenum disulfide (MoS2) nanosheets (NSs) have been widely used as photothermal agents and as potential carriers of antitumor drugs. Their spatial thermal effects have been extensively explored for use at physiological and hyperthermic temperatures (37 to 46 °C). Furthermore, the modulation of the spatial thermal distributions with these NSs may have even more profound applications in the microstructural control of biomaterials at cryogenic temperatures (-196 to 37 °C). These applications include bioinspired microfabrication via freezing, food and drug freeze-drying, and biomaterial cryopreservation. However, such thermal effects of NSs and their applications at cryogenic temperatures had never been fully explored. Therefore, in this study, we have utilized the near-infrared laser induced photothermal effects of GO and MoS2 NSs to suppress the ice nucleation and ice crystal growth during warming of the biosamples. Using this approach, biological cells subjected to fast cooling to a deeply frozen state (-196 °C) were successfully recovered with high survival rates and full biological functionality. Thus, we provide a NS based effective approach to control the crystallization behaviors of water during warming at cryogenic temperatures, as NSs may have wide applications in both materials science and bioengineering.

Photothermal Therapy Generates a Thermal Window of Immunogenic Cell Death in Neuroblastoma

A thermal "window" of immunogenic cell death (ICD) elicited by nanoparticle-based photothermal therapy (PTT) in an animal model of neuroblastoma is described. In studies using Prussian blue nanoparticles to administer photothermal therapy (PBNP-PTT) to established localized tumors in the neuroblastoma model, it is observed that PBNP-PTT conforms to the "more is better" paradigm, wherein higher doses of PBNP-PTT generates higher cell/local heating and thereby more cell death, and consequently improved animal survival. However, in vitro analysis of the biochemical correlates of ICD (ATP, high-motility group box 1, and calreticulin) elicited by PBNP-PTT demonstrates that PBNP-PTT triggers a thermal window of ICD. ICD markers are highly expressed within an optimal temperature (thermal dose) window of PBNP-PTT (63.3-66.4 °C) as compared with higher (83.0-83.5 °C) and lower PBNP-PTT (50.7-52.7 °C) temperatures, which both yield lower expression. Subsequent vaccination studies in the neuroblastoma model confirm the in vitro findings, wherein PBNP-PTT administered within the optimal temperature window results in long-term survival (33.3% at 100 d) compared with PBNP-PTT administered within the higher (0%) and lower (20%) temperature ranges, and controls (0%). The findings demonstrate a tunable immune response to heat generated by PBNP-PTT, which should be critically engaged in the administration of PTT for maximizing its therapeutic benefits.

Determination of sulfonamides in milk by capillary electrophoresis with PEG@MoS2 as a dispersive solid-phase extraction sorbent

A synthetic polyethylene glycol-molybdenum disulfide (PEG@MoS₂) composite was prepared using a simple method, and the application of this material in dispersive solid-phase extraction (DSPE) was investigated for the enrichment of eight sulfonamides (SAs) in milk samples. The composite was characterized by energy dispersive spectroscopy, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy and Brunauer-Emmett-Teller measurements. The results showed that the MoS₂ synthesized in the presence of PEG has the advantage of a larger surface area and that the adsorption effect of this MoS₂ was enhanced. After extraction, the eight SAs were separated by capillary zone electrophoresis with a good linear relationship (R² > 0.9902) in the range of 0.3-30 µg ml^-1 and good precision (between 0.32% and 9.83%). Additionally, good recoveries (between 60.52% and 110.91%) were obtained for the SAs in the milk samples. The developed PEG@MoS₂-based DSPE method could be applied for the enrichment of SAs in real milk samples.

2D MoS2 Nanostructures for Biomedical Applications

MoS₂ nanosheets, a typical kind of layered transition metal dichalcogenides with the 2D structure and many unique physical and chemical properties, have attracted a lot of research interests in various fields. Typically, MoS₂ nanosheets present similarities to graphene in terms of their large surface area and strong absorbance in near-infrared region, which in combination with their easily functionalized surface make them promising nanoplatforms in biomedical applications. Herein, the progress of MoS₂ nanosheets and their composites in the area of nanomedicine, with the emphasis on their synthesis and modification strategies, their biomedical applications in biosensing, imaging and therapy, as well as evaluations of their in vivo behaviors and toxicology profiles are summarized. Finally, the challenges and opportunities of applying MoS₂ -based nanomaterials in the biomedicine areas will be discussed.

Monolayer Nanosheets with an Extremely High Drug Loading toward Controlled Delivery and Cancer Theranostics

2D nanomaterials have attracted considerable research interest in drug delivery systems, owing to their intriguing quantum size and surface effect. Herein, Gd³⁺ -doped monolayered-double-hydroxide (MLDH) nanosheets are prepared via a facile bottom-up synthesis method, with a precisely controlled composition and uniform morphology. MLDH nanosheets as drug carrier are demonstrated in coloading of doxorubicin and indocyanine green (DOX&ICG), with an ultrahigh drug loading content (LC) of 797.36% and an encapsulation efficiency (EE) of 99.67%. This is, as far as it is known, the highest LC level at nearly 100% of EE among previously reported 2D drug delivery systems so far. Interestingly, the as-prepared DOX&ICG/MLDH composite material shows both pH-controlled and near-infrared-irradiation-induced DOX release, which holds a promise in stimulated drug release. An in vivo dual-mode imaging, including near-infrared fluorescence and magnetic resonance imaging, enables a noninvasive visualization of distribution profiles at the tumor site. In addition, in vitro and in vivo therapeutic evaluations demonstrate an excellent trimode synergetic anticancer activity and superior biocompatibility of DOX&ICG/MLDH. Therefore, MLDH nanosheets provide new perspectives in the design of multifunctional nanomedicine, which shows promising applications in controlled drug delivery and cancer theranostics.

BSA-modified poly(pyrrole-3-carboxylic acid) nanoparticles as carriers for combined chemo-photothermal therapy

Homogenous poly(pyrrole-3-carboxylic acid) nanoparticles with high near-infrared absorption and abundant functional groups were fabricated using a facile reverse microemulsion method.

Application of Nanocomposites in Cancer Immunotherapy

Despite the clinical advances in oncology, cancer is still the major cause of death worldwide. Recent research demonstrates that the immune system plays a critical role in preventing tumor occurrence and development. The focus on cancer treatment has been shifted from directly targeting the tumor cells to motivating the immune system to achieve this goal. However, the activity of immune system is often suppressed in cancer patients. To boost the anti-tumor immunity against cancers, various nanocomposites have been developed to enhance the efficacy of immunostimulatory agents. Here, we review current advances in nanomaterial-mediated immunotherapy for the treatment of cancer, with an emphasis on applications of nanocomposites as immunoadjuvants in cancer therapy.

Nanoscale Zeolitic Imidazolate Framework-8 as Efficient Vehicles for Enhanced Delivery of CpG Oligodeoxynucleotides

CpG oligodeoxynucleotides (ODNs) activate the immune system and induce Th 1 responses by stimulation of Toll-like receptor 9 (TLR9). Thus, CpG ODNs have become immunotherapeutics against various diseases including cancers, allergies, and infection. However, applications of CpG ODNs are largely limited because of their easy degradation by DNase as well as inefficient cellular uptake. Development of efficient delivery systems capable of transferring CpG ODNs into immune cells is important to enhance their therapeutic efficacy. Herein, for the first time, we demonstrated the construction of a novel CpG ODNs delivery system by encapsulating CpG ODNs into zeolitic imidazolate framework-8 (ZIF-8) nanoparticles. ZIF-8 possessed high CpG ODNs loading capacity due to its porous structure. ZIF-8/CpG ODNs complexes exhibited good stability in a physiological environment but effectively released CpG ODNs in acid conditions corresponding to the TLR 9-localized endolysosomes. ZIF-8/CpG ODNs complexes had no cytotoxicity in contrast to ZIF-8. ZIF-8 significantly increased the intracellular uptake of CpG ODNs in RAW264.7 cells, which further enhanced the secretion of immune cytokines both in vitro and in vivo. Our results suggest that nanoscale metal-organic frameworks (MOFs) can serve as ideal vehicles for the delivery of CpG ODNs.

MoS2-Based multipurpose theranostic nanoplatform: realizing dual-imaging-guided combination phototherapy to eliminate solid tumor via a liquefaction necrosis process

In this work, the MoS₂ based nanoplatform could realize imaging-guide phototherapy for eliminating solid tumor via a liquefaction necrosis process.

Transferrin-decorated, MoS2-capped hollow mesoporous silica nanospheres as a self-guided chemo–photothermal nanoplatform for controlled drug release and thermotherapy

In this targeted nanoplatform, MoS₂ nanosheets act as the gatekeepers as well as photothermal agent. After NIR triggered endosomal escape, DOX can be released in the presence of intracellular GSH.