pH-responsive Ag2S nanodots loaded with heat shock protein 70 inhibitor for photoacoustic imaging-guided photothermal cancer therapy

Multifunctional long afterglow nanoparticles with enhanced photothermal effects for in vivo imaging and tumor-targeting therapy

Considering the excellent properties such as deep tissue penetration, high signal-to-noise ratio, and in-situ recharge and reactivation, near-infrared luminescence long afterglow nanoparticles show considerable promise for biological application, especially in multifunctional imaging, targeting, and synergistic therapeutic. In this paper, Zn3Ga4GeO11: 0.1 % Cr3+, 1 % Yb3+, 0.1 % Tm3+@Ag-FA (ZGGO@Ag-FA, ZGA-FA) nanoparticles were synthesized by in-situ growth of Ag nanoparticles on the surface of long afterglow nanoparticles, and further modified with folic acid. Through precise adjustments, the luminescent properties of ZnGa2O4 were enhanced and notably boosted the photothermal effect of Ag by leveraging the upconversion emission of ZGGO, with a photothermal conversion efficiency reaching about 59.9 %. The ZGA-FA nanoparticles are ultra-small, measuring less than 50 nm. The modification with folic acid provides the ZGA-FA nanoparticles with excellent tumor-targeting capabilities, demonstrating effective enrichment and retention in tumor tissues, thus enabling long-term imaging and therapy through in vivo re-excitation. Due to its stable photothermal effect, outstanding near-infrared (NIR) afterglow imaging, and red-light charged characteristics, combined with effective tumor-targeting abilities, the therapeutic strategy proposed by this study has significant potential for clinical applications.

Tumor Microenvironment-Responsive Biodegradable Nanomedicine for Self-Enhanced Synergistic Chemo-, Photothermal, and Chemodynamic Therapy

The nanoscale multidrug codelivery system for synergistic therapy is an effective strategy for tumor treatment. However, the low drug delivery efficiency and poor therapeutic effects limit its application. Here, based on the coordination effect of Artemisinin (Art), quercetin (Qc), and Fe3+, we had constructed a safe and efficient carrier-free hyaluronic acid (HA)-modified Art-Fe-Qc nanoparticles (AFQ@HA NPs) for enhanced chemotherapy/photothermal therapy (PTT)-chemodynamic therapy (CDT) synergistic therapy, which achieved an ultrahigh drug loading efficiency and a multifunction anticancer strategy. The results showed that high drug loading was achieved based on drug coordination self-assembly, with Art and Qc contents of 38.6 and 42.7%, respectively. At the same time, based on the Qc-Fe coordination molecular network, the system had excellent photothermal conversion performance with an efficiency of 57.3% and could effectively inhibit the expression of HSP70, achieving enhanced PTT. Further, under the stimulation of excessive H2O2 and glutathione (GSH) in the tumor microenvironment, the AFQ@HA NPs were continuously degraded, while releasing Art and Fe3+/Fe2+ to achieve iron ion-enhanced CDT. The results of in vitro and in vivo experiments showed that AFQ@HA NPs could achieve chemotherapy-PTT-CDT synergistic therapy in response to tumor microenvironment by passively targeting and actively targeting tumor cells with CD44, demonstrating its excellent targeted antitumor effects.

Coadministration of Quercetin and Indocyanine Green via PEGylated Phospholipid Micelles for Augmented Chem-Photothermal Combination Tumor Therapy

A significant impediment persists in developing multicomponent nanomedicines designed to dismantle the heat shock protein (HSP)-based protective mechanism of malignant tumors during photothermal therapy. Herein, well-defined PEGylated phospholipid micelles were utilized to coencapsulate quercetin (QUE, a natural anticancer agent and potent HSP inhibitor) and indocyanine green (ICG, a photothermal agent) with the aim of achieving synchronized and synergistic drug effects. The subsequent investigations validated that the tailored micellar system effectively enhanced QUE's water solubility and augmented its cellular internalization efficiency. Intriguingly, the compositional PEGylated phospholipids induced extraordinary endoplasmic reticulum stress, thereby sensitizing the tumor cells to QUE. Furthermore, QUE played a crucial role in inhibiting the stress-induced overexpression of HSP70, thereby augmenting the photothermal efficacy of ICG. In systemic applications, the proposed nanotherapeutics exhibited preferential accumulation within tumors and exerted notable tumoricidal effects against 4T1 xenograft tumors under 808 nm near-infrared irradiation, facilitated by prominent near-infrared fluorescence imaging-guided chemo-photothermal therapy. Therefore, our strategy for fabricating multicomponent nanomedicines emerges as a coordinated platform for optimizing antitumor therapeutic efficacy and offers valuable insights for diverse therapeutic modalities.

A Bioinspired Photosensitizer Performs Tumor Thermoresistance Reversion to Optimize the Atraumatic Mild-Hyperthermia Photothermal Therapy for Breast Cancer

Mild-hyperthermia photothermal therapy (mPTT) has therapeutic potential with minimized damage to normal tissues. However, the poorly vascularized tumor area severely hampers the penetration of photothermal agents (PTAs), resulting in their heterogeneous distribution and the subsequent heterogeneous local temperature during mPTT. The presence of regions below the therapeutic 42 °C threshold can lead to incomplete tumor ablation and potential recurrence. Additionally, tumor anti-apoptosis and cytoprotection pathways, particularly activated thermoresistance, can nullify mild hyperthermia-induced tumor damage. Therefore, a bioinspired photosensitizer decorated with leucine to form biomimetic nanoclusters (CP-PLeu nanoparticles (NPs)) aimed at achieving rapid and homogeneous accumulation in tumors, is introduced. Moreover, CP-PLeu exhibits photodynamic effects that reverse tumor thermoresistance and physiological repair mechanisms, thereby inhibiting tumor resistance to hyperthermia. With the addition of NIR-II laser irradiation, CP-PLeu optimizes the therapeutic efficacy of mPTT and contributes to a minimally invasive therapeutic process for breast cancer. This therapeutic strategy, utilizing a biomimetic photosensitizer for homogeneous distribution of therapeutic temperature and photoactivated reversal of tumor thermoresistance, successfully achieves efficient breast tumor inhibition through an atraumatic mPTT process.

Cyanine dyes in the mitochondria-targeting photodynamic and photothermal therapy

Mitochondrial dysregulation plays a significant role in the carcinogenesis. On the other hand, its destabilization strongly represses the viability and metastatic potential of cancer cells. Photodynamic and photothermal therapies (PDT and PTT) target mitochondria effectively, providing innovative and non-invasive anticancer therapeutic modalities. Cyanine dyes, with strong mitochondrial selectivity, show significant potential in enhancing PDT and PTT. The potential and limitations of cyanine dyes for mitochondrial PDT and PTT are discussed, along with their applications in combination therapies, theranostic techniques, and optimal delivery systems. Additionally, novel approaches for sonodynamic therapy using photoactive cyanine dyes are presented, highlighting advances in cancer treatment.

Enhancing Photothermal/Photodynamic Therapy for Glioblastoma by Tumor Hypoxia Alleviation and Heat Shock Protein Inhibition Using IR820-Conjugated Reduced Graphene Oxide Quantum Dots

We use low-molecular-weight branched polyethylenimine (PEI) to produce cytocompatible reduced graphene oxide quantum dots (rGOQD) as a photothermal agent and covalently bind it with the photosensitizer IR-820. The rGOQD/IR820 shows high photothermal conversion efficiency and produces reactive oxygen species (ROS) after irradiation with near-infrared (NIR) light for photothermal/photodynamic therapy (PTT/PDT). To improve suspension stability, rGOQD/IR820 was PEGylated by anchoring with the DSPE hydrophobic tails in DSPE-PEG-Mal, leaving the maleimide (Mal) end group for covalent binding with manganese dioxide/bovine serum albumin (MnO2/BSA) and targeting ligand cell-penetrating peptide (CPP) to synthesize rGOQD/IR820/MnO2/CPP. As MnO2 can react with intracellular hydrogen peroxide to produce oxygen for alleviating the hypoxia condition in the acidic tumor microenvironment, the efficacy of PDT could be enhanced by generating more cytotoxic ROS with NIR light. Furthermore, quercetin (Q) was loaded to rGOQD through π-π interaction, which can be released in the endosomes and act as an inhibitor of heat shock protein 70 (HSP70). This sensitizes tumor cells to thermal stress and increases the efficacy of mild-temperature PTT with NIR irradiation. By simultaneously incorporating the HSP70 inhibitor (Q) and the in situ hypoxia alleviating agent (MnO2), the rGOQD/IR820/MnO2/Q/CPP can overcome the limitation of PTT/PDT and enhance the efficacy of targeted phototherapy in vitro. From in vivo study with an orthotopic brain tumor model, rGOQD/IR820/MnO2/Q/CPP administered through tail vein injection can cross the blood-brain barrier and accumulate in the intracranial tumor, after which NIR laser light irradiation can shrink the tumor and prolong the survival times of animals by simultaneously enhancing the efficacy of PTT/PDT to treat glioblastoma.

Self-Delivery Nanomedicines Reverse Thermal Resistance to Enhance Tumor Mild-Temperature Photothermal Therapy

Tumoral thermal defense mechanisms considerably attenuate the therapeutic outcomes of mild-temperature photothermal therapy (PTT). Thus, developing a simple, efficient, and universal therapeutic strategy to sensitize mild-temperature PTT is desirable. Herein, we report self-delivery nanomedicines ACy NPs comprising a near-infrared (NIR) photothermal agent (Cypate), mitochondrial oxidative phosphorylation inhibitor (ATO), and distearoylphosphatidylethanolamine-polyethylene glycol 2000 (DSPE-PEG2000), which have a high drug-loading efficiency that can reverse tumoral thermal resistance, thereby increasing mild-temperature PTT efficacy. ACy NPs achieved targeted tumor accumulation and performed NIR fluorescence imaging capability in vivo to guide tumor PTT for optimized therapeutic outcomes. The released ATO reduced intracellular ATP levels to downregulate multiple heat shock proteins (including HSP70 and HSP90) before PTT, which reversed the thermal resistance of tumor cells, contributing to the excellent results of mild-temperature PTT in vitro and in vivo. Therefore, this study provides a simple, biosafe, advanced, and universal heat shock protein-blocking strategy for tumor PTT.

Hydrogel design to overcome thermal resistance and ROS detoxification in photothermal and photodynamic therapy of cancer

Responsive heat resistance (by heat shock protein upregulation) and spontaneous reactive oxygen species (ROS) detoxification have been regarded as the major obstacles for photothermal/photodynamic therapy of cancer. To overcome the thermal resistance and improve ROS susceptibility in breast cancer therapy, Au ion-crosslinked hydrogels including indocyanine green (ICG) and polyphenol are devised. Au ion has been introduced for gel crosslinking (by catechol-Au3+ coordination), cellular glutathione depletion, and O2 production from cellular H2O2. ICG can generate singlet oxygen from O2 (for photodynamic therapy) and induce hyperthermia (for photothermal therapy) under the near-infrared laser exposure. (-)-Epigallocatechin gallate downregulates heat shock protein to overcome heat resistance during hyperthermia and exerts multiple anticancer functions in spite of its ironical antioxidant features. Those molecules are concinnously engaged in the hydrogel structure to offer fast gel transformation, syringe injection, self-restoration, and rheological tuning for augmented photo/chemotherapy of cancer. Intratumoral injection of multifunctional hydrogel efficiently suppressed the growth of primary breast cancer and completely eliminated the residual tumor mass. Proposed hydrogel system can be applied to tumor size reduction prior to surgery of breast cancer and the complete remission after its surgery.

Application of Nanoparticles for Efficient Delivery of Quercetin in Cancer Cells

Quercetin (Qu, 3,5,7,3', 4'-pentahydroxyflavanone) is a natural polyphenol compound abundantly found in health food or plant-based products. In recent decades, Qu has gained significant attention in the food, cosmetic, and pharmaceutic industries owning to its wide beneficial therapeutic properties such as antioxidant, anti-inflammatory and anticancer activities. Despite the favorable roles of Qu in cancer therapy due to its numerous impacts on the cell signaling axis, its poor chemical stability and bioavailability, low aqueous solubility as well as short biological half-life have limited its clinical application. Recently, drug delivery systems based on nanotechnology have been developed to overcome such limitations and enhance the Qu biodistribution following administration. Several investigations have indicated that the nano-formulation of Qu enjoys more remarkable anticancer effects than its free form. Furthermore, incorporating Qu in various nano-delivery systems improved its sustained release and stability, extended its circulation time, enhanced its accumulation at target sites, and increased its therapeutic efficiency. The purpose of this study was to provide a comprehensive review of the anticancer properties of various Qu nano-formulation to augment their effects on different malignancies. Various targeting strategies for improving Qu delivery, including nanoliposomes, lipids, polymeric, micelle, and inorganic nanoparticle NPs, have been discussed in this review. The results of the current study illustrated that a combination of appropriate nano encapsulation approaches with tumor-oriented targeting delivery might lead to establishing QU nanoparticles that can be a promising technique for cancer treatment.

Challenges and opportunities for improving the druggability of natural product: Why need drug delivery system?

Bioactive natural products (BNPs) are the marrow of medicinal plants, which are the secondary metabolites of organisms and have been the most famous drug discovery database. Bioactive natural products are famous for their enormous number and great safety in medical applications. However, BNPs are troubled by their poor druggability compared with synthesis drugs and are challenged as medicine (only a few BNPs are applied in clinical settings). In order to find a reasonable solution to improving the druggability of BNPs, this review summarizes their bioactive nature based on the enormous pharmacological research and tries to explain the reasons for the poor druggability of BNPs. And then focused on the boosting research on BNPs loaded drug delivery systems, this review further concludes the advantages of drug delivery systems on the druggability improvement of BNPs from the perspective of their bioactive nature, discusses why BNPs need drug delivery systems, and predicts the next direction.

Quercetin alleviates tubulointerstitial inflammation by inhibiting exosomes-mediated crosstalk between tubular epithelial cells and macrophages

BACKGROUND

Tubulointerstitial inflammation (TII) is a critical pathological feature of kidney disease leading to renal fibrosis, and its treatment remains a major clinical challenge. We sought to explore the role of quercetin, a potential exosomes inhibitor, in exosomes release and TII.

METHODS

The effects of quercetin on exosomes release and TII were examined by two TII mouse models: the unilateral ureteral obstruction (UUO) models and the LPS-induced mouse models. In vitro, exosomes-mediated crosstalk between tubular epithelial cells (TECs) and macrophages was performed to investigate the mechanisms by which quercetin inhibited exosomes and TII.

RESULTS

In this study, we found that exosomes-mediated crosstalk between TECs and macrophages contributed to the development of TII. In vitro, exosomes released from LPS-stimulated TECs induced increased expression of inflammatory cytokines and fibrotic markers in Raw264·7 cells and vice versa. Interestingly, heat shock protein 70 (Hsp70) or Hsp90 proteins could control exosomes release from TECs and macrophages both in vivo and in vitro. Importantly, quercetin, a previously recognized heat shock protein inhibitor, could significantly reduce exosomes release in TII models by down-regulating Hsp70 or Hsp90. Quercetin abrogated exosomes-mediated intercellular communication, which attenuated TII and renal fibrosis accordingly.

CONCLUSION

Quercetin could serve as a novel strategy for treatment of tubulointerstitial inflammation by inhibiting the exosomes-mediated crosstalk between tubules and macrophages.

HSP70 Family in Cancer: Signaling Mechanisms and Therapeutic Advances

The 70 kDa heat shock proteins (HSP70s) are a group of highly conserved and inducible heat shock proteins. One of the main functions of HSP70s is to act as molecular chaperones that are involved in a large variety of cellular protein folding and remodeling processes. HSP70s are found to be over-expressed and may serve as prognostic markers in many types of cancers. HSP70s are also involved in most of the molecular processes of cancer hallmarks as well as the growth and survival of cancer cells. In fact, many effects of HSP70s on cancer cells are not only related to their chaperone activities but rather to their roles in regulating cancer cell signaling. Therefore, a number of drugs directly or indirectly targeting HSP70s, and their co-chaperones have been developed aiming to treat cancer. In this review, we summarized HSP70-related cancer signaling pathways and corresponding key proteins regulated by the family of HSP70s. In addition, we also summarized various treatment approaches and progress of anti-tumor therapy based on targeting HSP70 family proteins.

Polydopamine nanoparticles coated with a metal-polyphenol network for enhanced photothermal/chemodynamic cancer combination therapy

Polydopamine nanoparticles (PDA NPs) are commonly used for photothermal therapy (PTT) of cancer because of their good biocompatibility and photothermal conversion capability. However, it is difficult to achieve a good tumor inhibition effect with a single PTT of PDA. Therefore, in this work, we prepared a combined anticancer nanosystem for enhanced chemodynamic therapy (CDT)/PTT by coating PDAs with an (-)-epigallocatechin gallate (EGCG)/iron (Fe) metal-polyphenol network (MPN). The MPN shell of this nanosystem named EGCG@PDA is degraded by the weakly acidic environment intracellular, releasing EGCG and Fe³⁺. EGCG inhibits the expression of heat shock proteins (HSPs) in cancer cells, thus eliminating their thermal protection against cancer cells for enhanced PTT. Meanwhile, the reductive EGCG can also reduce Fe³⁺ to Fe²⁺, to catalyze the decomposition of overexpressed hydrogen peroxide (H₂O₂) in cancer cells to generate strong oxidative hydroxyl radicals (OH), i.e., catalyzing the Fenton reaction, for CDT. After the Fenton reaction, the re-oxidized Fe ions can be reduced again by EGCG and reused to catalyze the Fenton reaction, which can achieve enhanced CDT. Both in vitro and in vivo studies have shown that EGCG@PDA has low dark toxicity and good anticancer effects. It is expected to be used for precision cancer therapy.

Small-size Ti3C2Tx MXene nanosheets coated with metal-polyphenol nanodots for enhanced cancer photothermal therapy and anti-inflammation

As a controllable, simple method with few side effects, near-infrared (NIR) light-based photothermal therapy (PTT) has been proven an effective cancer therapeutic approach. However, PTT-induced inflammation is a potential negative factor. And the overexpressed heat shock proteins (HSPs) by cancer cells can protect them from hyperthermia during PTT. In this work, small-size Ti₃C₂T_x MXene nanosheets with high photothermal conversion efficiency in the region of NIR, high cargo loading capability and good free radical scavenging capability were chosen for cancer PTT and anti-inflammation. And (-)-epigallocatechin gallate (EGCG) was applied to form EGCG/Fe metal-polyphenol nanodots on the nanosheets. EGCG being released in acid cancer cells could reduce the expression of HSPs and could be used for anti-inflammation. As a result, the complex nanosheets named MXene@EGCG could achieve enhanced cancer PTT and be anti-inflammatory. Both in vitro and in vivo studies proved the good photothermal ability of MXene@EGCG and demonstrated that it could inhibit the expression of HSPs in tumor cells and relieve PTT-induced inflammation. Therefore, the nanosheets show good results in tumor ablation with a low level of inflammation, which provides another possibility for cancer therapy. STATEMENT OF SIGNIFICANCE: Photothermal therapy (PTT)-induced inflammation plays an essential role in some important stages of tumor development and is unfavorable for cancer treatment. And hyperthermia leads to the overexpression of heat shock proteins (HSPs) in cancer cells, which limits the therapeutic effect of PTT. Therefore, we coated small-size Ti₃C₂T_x MXene nanosheets with (-)-epigallocatechin gallate (EGCG)/Fe metal-polyphenol nanodots and named them as MXene@EGCG. This system shows a good photothermal conversion efficiency at 808 nm. And it can release EGCG in cancer cells to inhibit the expression of HSPs, thus achieving an enhanced cancer PTT. Both MXene and EGCG can also diminish the PTT-trigged inflammation. Both in vitro and in vivo studies prove the good anti-cancer PTT effect and anti-inflammation capability of MXene@EGCG.

Thermoacoustic Imaging-Guided Thermo-Chemotherapy for Hepatocellular Carcinoma Sensitized by a Microwave-Responsive Nitric Oxide Nanogenerator

Imaging-guided percutaneous microwave thermotherapy has been regarded as an important alternative nonsurgical therapeutic strategy for hepatocellular carcinoma (HCC) that provides excellent local tumor control and favorable survival benefit. However, providing a high-resolution, real-time, and noninvasive imaging technique for intraoperative guidance and controlling postoperative residual tumor recurrence are urgent needs for the clinical setting. In this study, a cisplatin (CDDP)-loaded nanocapsule (NPs@CDDP) with microwave responsive property was prepared to simultaneously serve as a contrast agent of emerging thermoacoustic imaging and a sensitizing agent of microwave thermo-chemotherapy. Accompanying the enzymolysis in the tumor microenvironment, the NPs@CDDP responsively release l-arginine (l-Arg) and CDDP. l-Arg with excellent microwave-absorbing property allowed it to serve as a thermoacoustic imaging contrast agent for accurately delineating the tumor and remarkably increasing tumor temperature under ultralow power microwave irradiation. Apart from the chemotherapeutic effect, CDDP elevated the intracellular H₂O₂ level through cascade reactions and further accelerated the continuous transformation of l-Arg to nitric oxide (NO), which endowed the NPs@CDDP with NO-generation capability. Notably, the high concentration of intracellular NO was proved to aggravate lipid peroxidation and greatly improved the efficacy of microwave thermo-chemotherapy. Thereby, NPs@CDDP was expected to serve as a theranostic agent integrating the functions of tumor microenvironment-responsive drug delivery system, contrast agent of thermoacoustic imaging, thermal sensitizing agent, and NO nanogenerator, which was promising to provide a potential imaging-guided therapeutic strategy for HCC.

A redox reaction-induced ratiometric fluorescence platform for the specific detection of ascorbic acid based on Ag2S quantum dots and multifunctional CoOOH nanoflakes

In this work, a ratiometric fluorescent nanoplatform for the detection of ascorbic acid (AA) was constructed based on the Ag₂S quantum dots (QDs) and multifunctional hydroxyl cobalt oxide nanoflakes (CoOOH NFs). Ag₂S QDs can be assembled on the surface of CoOOH NFs by electrostatic adsorption, resulting in the quenching of the NIR fluorescence emission of Ag₂S QDs at 680 nm effectively through the inner filter effect (IFE). o-Phenylenediamine (OPD), a common substrate of oxidase-like (OXD) mimic, is rapidly oxidized into the fluorescent product of 2,3-diaminophenazine (DAP) with the appearance of an emission peak at 575 nm under the catalysis of CoOOH NFs. After AA was added, the fluorescence emission of DAP declined because of the decline in the OXD-like activity of CoOOH NFs due to the transformation of Co²⁺. Simultaneously, Ag₂S QDs were released, accompanied by the recovery of red fluorescence. These two fluorescent signals can be excited at the same excitation wavelength, simplifying the detection procedure. Using F₅₇₅/F₆₈₀ as the readout, the quantification of AA can be realized with the linear range and detection limit of 0.2 μM-20 mM and 0.014 μM, respectively. The ratiometric fluorescence sensor can be effectively used to determine the content of AA in real samples such as juice and serum. This work integrates the in-situ formation of the fluorescent species via the catalysis of the nanozyme and the redox reaction to destroy the CoOOH NFs nanozyme as well as the two dimensional nanoflake induced turn-off-on strategy for Ag₂S QDs, which provides a specific strategy for the selective detection of AA and may offer a reliable approach for the construction of other biosensing platforms.

Glucose oxidase-amplified CO generation for synergistic anticancer therapy via manganese carbonyl-caged MOFs

Carbon monoxide (CO) as one of the therapeutic gaseous molecules has been widely applied for treating various diseases, especially in cancer therapy. However, the in situ-triggered and efficient transport of CO to tumors are the primary obstacles that limit its clinical applicability. To address this obstacle, herein, a H₂O₂-triggered CO gas releasing nanoplatform has been designed by embedding manganese carbonyl (MnCO) into Zr (IV)-based metal-organic frameworks (MOFs). The porous structures of MOFs provide encapsulation capacity for glucose oxidase (GOx) loading, thereby catalyzing the endogenous glucose into gluconic acid and H₂O₂ to accelerate CO release and energy depletion. In the meantime, the Mn²⁺ produced by MnCO can react with intracellular H₂O₂ via the Fenton reaction to form cytotoxic •OH. Therefore, the synthesized gas nanogenerator demonstrated a synergistic efficacy of CO gas therapy, reactive oxygen species (ROS)-mediated therapy, and energy starvation to prevent tumor growth. Both in vitro and in vivo studies indicated that this multifunctional nanoplatform not only successfully inhibited tumors through a synergistic effect, but also provided a new technique for the creation of starvation/gas/chemodynamic combination therapy in a single material. STATEMENT OF SIGNIFICANCE: In this study, we developed a H₂O₂ responsive CO gas nanogenerator to augment the in-situ generation of CO gas for combined modality therapy of tumors. The nanogenerator was constructed by encapsulating glucose oxidase (GOx) and manganese carbonyl (MnCO) into UiO-67-bpy, which can catalyze the conversion of intracellular glucose to H₂O₂ for cutting off energy supply of cancer cells. Meanwhile, the cumulated H₂O₂ can trigger the release of CO for gas therapy and generation of •OH for chemodynamic therapy (CDT) via the Fenton-like reaction, thereby resulting in apoptosis of the cancer cells. Collectively, our designed nanotherapeutic agent not only displays the synergistic therapy efficacy of starvation-enhanced CO gas therapy and CDT, but also provides an efficient strategy for developing the intelligent nanocarrier for CO gas delivery and release.

Acidity-Activatable Nanoparticles with Glucose Oxidase-Enhanced Photoacoustic Imaging and Photothermal Effect, and Macrophage-Related Immunomodulation for Synergistic Treatment of Biofilm Infection

The pH-responsive theragnostics exhibit great potential for precision diagnosis and treatment of diseases. Herein, acidity-activatable nanoparticles of GB@P based on glucose oxidase (GO) and polyaniline are developed for treatment of biofilm infection. Catalyzed by GO, GB@P triggers the conversion of glucose into gluconic acid and hydrogen peroxide (H₂ O₂ ), enabling an acidic microenvironment-activated simultaneously enhanced photothermal (PT) effect/amplified photoacoustic imaging (PAI). The synergistic effects of the enhanced PT efficacy of GB@P and H₂ O₂ accelerate biofilm eradication because the penetration of H₂ O₂ into biofilm improves the bacterial sensitivity to heat, and the enhanced PT effect destroys the expressions of extracellular DNA and genomic DNA, resulting in biofilm destruction and bacterial death. Importantly, GB@P facilitates the polarization of proinflammatory M1 macrophages that initiates macrophage-related immunity, which enhances the phagocytosis of macrophages and secretion of proinflammatory cytokines, leading to a sustained bactericidal effect and biofilm eradication by the innate immunomodulatory effect. Accordingly, the nanoplatform of GB@P exhibits the synergistic effects on the biofilm eradication and bacterial residuals clearance through a combination of the enhanced PT effect with immunomodulation. This study provides a promising nanoplatform with enhanced PT efficacy and amplified PAI for diagnosis and treatment of biofilm infection.

Tailoring Polymer-Based Nanoassemblies for Stimuli-Responsive Theranostic Applications

Polymer assemblies on the nanoscale represent a powerful toolbox for the design of theranostic systems when combined with both therapeutic compounds and diagnostic reporting ones. Here, recent advances in the design of theranostic systems for various diseases, containing-in their architecture-either polymers or polymer assemblies as one of the building blocks are presented. This review encompasses the general principles of polymer self-assembly, from the production of adequate copolymers up to supramolecular assemblies with theranostic functionality. Such polymer nanoassemblies can be further tailored through the incorporation of inorganic nanoparticles to endow them with multifunctional therapeutic and/or diagnostic features. Systems that change their architecture or properties in the presence of stimuli are selected, as responsivity to changes in the environment is a key factor for enhancing efficiency. Such theranostic systems are based on the intrinsic properties of copolymers or one of the other components. In addition, systems with a more complex architecture, such as multicompartments, are presented. Selected systems indicate the advantages of such theranostic approaches and provide a basis for further developments in the field.

A synergistic chemodynamic-photodynamic-photothermal therapy platform based on biodegradable Ce-doped MoOx nanoparticles

Near-infrared light-induced catalysts are considered to be potential nanoagents for tumor therapy. Cerium (Ce) is a non-biotoxic lanthanide element and exhibits variable valence states for catalytic reactions. In this work, we report a one-step hydrothermal synthesis for Ce-doped MoO_x (CMO) nanomaterials. The obtained CMO nanomaterials show high absorption in the NIR II regime and a high photothermal conversion efficiency of 67.7% (1064 nm). Moreover, due to the doping of Ce element, the consumption of hydrogen peroxide (H₂O₂) and glutathione (GSH) is boosted which enhances the chemodynamic and photodynamic therapy simultaneously. Under NIR II laser irradiation, the designed CMO nanocatalysts induce metabolism disruption and mitochondrial damage in the tumor cells. As-prepared CMO nanomaterials also show good biocompatibility and pH-responsive degradation behavior, which can be degraded rapidly under alkaline conditions (pH = 7.4) and remain stable in acidic solution (pH = 5.6). These properties make CMO nanomaterials ideal biodegradable nanotheranostic agents for synergistic chemodynamic-photodynamic-photothermal antitumor therapy.

Biomedical Photoacoustic Imaging for Molecular Detection and Disease Diagnosis: "Always-On" and "Turn-On" Probes

Photoacoustic (PA) imaging is a nonionizing, noninvasive imaging technique that combines optical and ultrasonic imaging modalities to provide images with excellent contrast, spatial resolution, and penetration depth. Exogenous PA contrast agents are created to increase the sensitivity and specificity of PA imaging and to offer diagnostic information for illnesses. The existing PA contrast agents are categorized into two groups in this review: "always-on" and "turn-on," based on their ability to be triggered by target molecules. The present state of these probes, their merits and limitations, and their future development, is explored.

Triggering Immune System With Nanomaterials for Cancer Immunotherapy

Cancer is a major cause of incidence rate and mortality worldwide. In recent years, cancer immunotherapy has made great progress in the preclinical and clinical treatment of advanced malignant tumors. However, cancer patients will have transient cancer suppression reaction and serious immune related adverse reactions when receiving immunotherapy. In recent years, nanoparticle-based immunotherapy, which can accurately deliver immunogens, activate antigen presenting cells (APCs) and effector cells, provides a new insight to solve the above problems. In this review, we discuss the research progress of nanomaterials in immunotherapy including nanoparticle-based delivery systems, nanoparticle-based photothermal and photodynamic immunotherapy, nanovaccines, nanoparticle-based T cell cancer immunotherapy and nanoparticle-based bacteria cancer immunotherapy. We also put forward the current challenges and prospects of immunomodulatory therapy.

A Smart Theranostic Prodrug System Activated by Reactive Oxygen Species for Regional Chemotherapy of Metastatic Cancer

Metastatic cancer is difficult to cure because of its uncontrollable nature and side effects during treatment. We constructed a reactive oxygen species (ROS)-activated smart theranostic prodrug system based on an ROS active site linked with both a targeting group and an anticancer drug for efficient regional chemotherapy of metastatic cancers. The optimized prodrug (Bio-(8)-MB-CPT) with biotin as the targeting group displayed high sensitivity towards ROS and selectively targeting ability towards cervical cancer cells, showing highly efficient drug release (up to 92 %) in vitro. Bio-(8)-MB-CPT thus exerted strong toxicity towards cervical cancer cells, but unlike the parent drug (camptothecin), showed no toxicity towards normal cells. Moreover, the prodrug displayed significantly enhanced antitumor efficacy in vivo and eradicated the tumor with no obvious side effects (inhibition of the tumor reached up to 99.9 %).

Quercetin- and rutin-based nano-formulations for cancer treatment: A systematic review of improved efficacy and molecular mechanisms

BACKGROUND

Natural products, with incredible chemical diversity, have been widely studied for their antitumor potential. Quercetin (QU) and quercetin glycoside (rutin), both polyphenolic flavonoids, stick out amongst the natural products, through various studies. Rutin (RU) and its aglycone (QU) have various biological properties that include antioxidant, anti-inflammatory, and anticarcinogenic activities. However, several side effects have restricted the efficacy of these polyphenolic flavonoids, which makes it necessary to use new strategies involving low and pharmacological doses of QU and RU, either alone or in combination with other anticancer drugs.

PURPOSE

The aim of this study is to present a comprehensive and critical evaluation of the anticancer ability of different nano-formulations of RU and QU for improved treatment of various malignancies.

METHODS

Studies were recognized via systematic searches of ScienceDirect, PubMed, and Scopus databases. Eligibility checks were conducted based upon predefined selection criteria. Ninety articles were included in this study.

RESULTS

There was conclusive evidence for the association between anticancer activity and treatment with RU or QU. Furthermore, studies indicated that nano-formulations of RU and QU have greater anticancer activities in comparison to either agent alone, which leads to increased efficiency for treating cancer.

CONCLUSION

The results of this systematic review demonstrate the anticancer activities of nano-formulations of RU and QU and their molecular mechanisms through preclinical studies. This paper also attempts to contribute to further research by addressing the current limitations/challenges and proposing additional studies to realize the full potential of RU- and QU-based formulations for cancer treatment.

Lysosomal activable Vorinostat carrier-prodrug self-assembling with BPQDs enables photothermal oncotherapy to reverse tumor thermotolerance and metastasis

Photothermal therapy (PTT) is becoming increasing prevalent in clinic for eradicating the primary tumor and improving cancer patients' compliance. However, photothermal resistance and distal metastasis still haunt the tumor treatment with PTT. Herein, on the basis that histone deacetylase acetylase inhibitor (HDACis) could activate the expression of anti-tumor gene and accelerate the differentiation and apoptosis of tumor cells, we propose that HDACis supplementing PTT could overcome those obstacles with appropriate drug-controlled release strategy. Thus, we fabricated a nano-complex of lysosomal activable vorinostat (SAHA) carrier-prodrug encapsulating black phosphorus quantum dots (BPQDs@PPS) to counter those challenges in PTT. With spherical morphology and favorable bio-safety, BPQDs@PPS could release BPQDs and Vorinostat spontaneously in lysosome, not only effectively inhibiting tumor growth, but also reversing tumor thermotolerance and metastasis within a PTT procedure. Especially, both western blot and immunofluorescence analysis validate that Vorinostat enables PTT to reverse tumor thermotolerance and distal metastasis by down-regulation of HSP70 and up-regulation of H3. Therefore, this research not only reveals the mechanism how HDACis supplement PTT in reversing tumor thermotolerance and metastasis, but also provides a promising prospect to upgrade clinical photothermal therapy.

HOCl-Activated Aggregation of Gold Nanoparticles for Multimodality Therapy of Tumors

Tumor microenvironment-responsive nanodrugs offer promising opportunities for imaging-guided precision therapy with reduced side effects. Considering that the antitumor effect is closely related to the size of the nanodrugs, it is particularly important to develop a therapeutic system with size adjustability in the tumor microenvironment, which is still a great challenge in the field of nanotheranostics. Herein, a reactive oxygen species (ROS)-activated aggregation strategy is reported for imaging-guided precision therapy of tumors. The ROS-activated nanoplatform is constructed based on gold nanoparticles (AuNPs) coated with an HOCl probe on its surface (namely, Au-MB-PEG NPs). The Au-MB-PEG NPs show high sensitivity toward HOCl, resulting in the modulation of surface charge and rapid aggregation of AuNPs, and simultaneous release of methylene blue as a photosensitizer for photodynamic therapy (PDT). In the tumor environment, the aggregated AuNPs ensure higher tumor accumulation and retention. Furthermore, the redshift of the absorption of aggregated AuNPs leads to activated photoacoustic imaging signals and photothermal therapy (PTT) under near-infrared irradiation. Au-MB-PEG NPs thus efficiently inhibit the tumor growth through combined PTT-PDT therapy. This work contributes to the design of stimuli-induced size-aggregation nanodrugs, thereby attaining advanced performance in cancer diagnosis and treatment.

Photoacoustic imaging in evaluating early intestinal ischemia injury and reperfusion injury in rat models

Background

It remains a challenge to distinguish whether the damaged intestine is viable in treating acute mesenteric ischemia. In this study, photoacoustic imaging (PAI) was used to observe intestinal tissue viability after ischemia and reperfusion injury in rats.

Methods

An in vivo study was conducted using forty male SD rats, which were randomly divided into a sham-operated (SO) group, a 1 h ischemia group, a 2 h ischemia group, and an ischemia-reperfusion (I/R) group with 10 rats in each group. In the ischemia group, the superior mesenteric artery (SMA) was isolated and clamped for 1 and 2 h, respectively, and in the I/R group, after ischemia for 1 h, the clamp was removed and reperfused for 1 h. The same time interval was used in the SO group. Immediately after establishing the animal model, a PAI examination was performed, and the small intestine was collected for histopathology.

Results

The levels of PAI parameters Hb, HbR, MAP 760, and MAP 840 were increased to different degrees in the ischemia groups, especially in the 2 h ischemia group, compared with the SO group (P<0.05), and with prolongation of the ischemia time, the injury was aggravated. All PAI signal levels except HbO in the I/R group were higher than those in the control group, and the increased range differed, especially in Hb and MAP 840. Using western blot, compared with the SO group, the BAX increased significantly in the 2 h ischemia group (P<0.05), and Caspase-3 in the experimental group was significantly higher than in the SO group (P<0.05). The level of HIF-1α increased in the 2 h ischemia group and I/R group (P<0.05), and TUNEL staining showed that the number of positive apoptotic nuclei in the 2 h ischemia group was significantly higher than in the SO group (P<0.05). Hematoxylin-eosin (HE) staining showed that ischemia for 2 hours was the most serious, with obvious mucosal damage, extensive epithelial injury, and bleeding.

Conclusions

PAI can be used as an effective tool to detect acute intestinal ischemia injury and quantitatively evaluate tissue viability.

Bi2S3@Ag2S nano-heterojunction decorated self-floating carbon fiber cloth and enhanced solar-driven photothermal-photocatalytic performance

The difficult recycle, secondary pollution and insufficient sunlight utilization of powder photocatalysts are main obstacles for practical applications. Bi₂S₃@Ag₂S heterojunction supported on surface of carbon fiber cloth (CC) are fabricated through hydrothermal in-situ growth method combined with ultrasonic loading strategy, which can be self-floated on water surface. Bi₂S₃@Ag₂S nano-heterojunction with narrow band gap shows enhanced full spectrum absorption, which is in favor of improving the photocatalytic-photothermal performance. Self-floating CC as a substrate not only absorbs solar light converting to thermal energy, but also favors the recycle of catalysts. The resultant Bi₂S₃@Ag₂S/CC composite films exhibit excellent photothermal conversion performance and photocatalytic degradation activity for tetracycline hydrochloride in low temperature wastewater under simulated sunlight. Experimental results confirm that the superoxide group (·O₂^-) is the main factor for the robust catalytic performance. The good photothermal-photocatalytic performance can be ascribed to the efficient absorption of sunlight for self-floating characteristics and high charge carriers separation efficiency of Bi₂S₃@Ag₂S nano-heterojunction. This novel self-floating photothermal-photocatalytic film will have potential applications in fields of environment.

Smart Responsive Nanoformulation for Targeted Delivery of Active Compounds From Traditional Chinese Medicine

Traditional Chinese medicine (TCM) has been used to treat disorders in China for ~1,000 years. Growing evidence has shown that the active ingredients from TCM have antibacterial, antiproliferative, antioxidant, and apoptosis-inducing features. However, poor solubility and low bioavailability limit clinical application of active compounds from TCM. “Nanoformulations” (NFs) are novel and advanced drug-delivery systems. They show promise for improving the solubility and bioavailability of drugs. In particular, “smart responsive NFs” can respond to the special external and internal stimuli in targeted sites to release loaded drugs, which enables them to control the release of drug within target tissues. Recent studies have demonstrated that smart responsive NFs can achieve targeted release of active compounds from TCM at disease sites to increase their concentrations in diseased tissues and reduce the number of adverse effects. Here, we review “internal stimulus–responsive NFs” (based on pH and redox status) and “external stimulus–responsive NFs” (based on light and magnetic fields) and focus on their application for active compounds from TCM against tumors and infectious diseases, to further boost the development of TCM in modern medicine.