Dual-inhibitory domain iCARs improve the efficiency of the AND-NOT gate CAR T strategy.

CAR (chimeric antigen receptor) T cell therapy has shown clinical success in treating hematological malignancies, but its treatment of solid tumors has been limited. One major challenge is on-target, off-tumor toxicity, where CAR T cells also damage normal tissues that express the targeted antigen. To reduce this detrimental side-effect, Boolean-logic gates like AND-NOT gates have utilized an inhibitory CAR (iCAR) to specifically curb CAR T cell activity at selected nonmalignant tissue sites. However, the strategy seems inefficient, requiring high levels of iCAR and its target antigen for inhibition. Using a TROP2-targeting iCAR with a single PD1 inhibitory domain to inhibit a CEACAM5-targeting CAR (CEACAR), we observed that the inefficiency was due to a kinetic delay in iCAR inhibition of cytotoxicity. To improve iCAR efficiency, we modified three features of the iCAR-the avidity, the affinity, and the intracellular signaling domains. Increasing the avidity but not the affinity of the iCAR led to significant reductions in the delay. iCARs containing twelve different inhibitory signaling domains were screened for improved inhibition, and three domains (BTLA, LAIR-1, and SIGLEC-9) each suppressed CAR T function but did not enhance inhibitory kinetics. When inhibitory domains of LAIR-1 or SIGLEC-9 were combined with PD-1 into a single dual-inhibitory domain iCAR (DiCARs) and tested with the CEACAR, inhibition efficiency improved as evidenced by a significant reduction in the inhibitory delay. These data indicate that a delicate balance between CAR and iCAR signaling strength and kinetics must be achieved to regulate AND-NOT gate CAR T cell selectivity.

Molecular mechanisms underlying the development of neuroendocrine prostate cancer.

Prostate cancer is the most common non-cutaneous cancer and the second leading cause of cancer-associated deaths among men in the United States. Androgen deprivation therapy (ADT) is the standard of care for advanced prostate cancer. While patients with advanced prostate cancer initially respond to ADT, the disease frequently progresses to a lethal metastatic form, defined as castration-resistant prostate cancer (CRPC). After multiple rounds of anti-androgen therapies, 20-25% of metastatic CRPCs develop a neuroendocrine (NE) phenotype. These tumors are classified as neuroendocrine prostate cancer (NEPC). De novo NEPC is rare and accounts for less than 2% of all prostate cancers at diagnosis. NEPC is commonly characterized by the expression of NE markers and the absence of androgen receptor (AR) expression. NEPC is usually associated with tumor aggressiveness, hormone therapy resistance, and poor clinical outcome. Here, we review the molecular mechanisms underlying the emergence of NEPC and provide insights into the future perspectives on potential therapeutic strategies for NEPC.

The effect of hyperthyroidism on cognitive function, neuroinflammation, and necroptosis in APP/PS1 mice.

BACKGROUND: Increasing evidence has linked the thyroid dysfunction to the pathogenesis of dementia. Evidence from clinical studies has demonstrated that hypothyroidism is related to an increased risk of dementia. But the association of hyperthyroidism with dementia is largely unknown. METHODS: We used the adenovirus containing thyrotropin receptor (TSHR) amino acid residues 1-289 (Ad-TSHR289)-induced Graves' disease (GD) phenotype in Alzheimer's disease (AD) model mice (APP/PS1 mice) to evaluate the effect of hyperthyroidism on the cognitive function and ß-amyloid (Aß) accumulation. RESULTS: GD mice exhibited a stable long-term hyperthyroidism and cognitive deficits. Single Cell RNA-sequencing analysis indicated that microglia function played a critical role in the pathophysiological processes in GD mice. Neuroinflammation and polarization of microglia (M1/M2 phenotype) and activated receptor-interacting serine/threonine protein kinase 3 (RIPK3)/mixed lineage kinase domain-like pseudo-kinase (MLKL)-mediated necroptosis contributed to the pathological process, including Aß deposition and neuronal loss. RIPK3 inhibitor could inhibit GD-mediated Aß accumulation and neuronal loss. CONCLUSIONS: Our findings reveal that GD hyperthyroidism aggravates cognitive deficits in AD mice and induces Aß deposition and neuronal loss by inducing neuroinflammation and RIPK3/MLKL-mediated necroptosis.

Obstructive sleep apnea hypopnea syndrome in ancient traditional Chinese medicine.

In western medicine, obstructive sleep apnea hypopnea syndrome (OSAHS) is an increasingly serious public health hazard, which is exacerbated by the obesity epidemic and an aging population. Ancient medical literature of traditional Chinese medicine (TCM) also recorded OSAHS-like symptoms but described the disease from a completely distinct theoretical perspective. The earliest records of snoring in ancient China can be traced back 2500 years. In TCM, the pathogenesis of OSAHS can be attributed mainly to turbid phlegm and blood stasis. Various TCM prescriptions, herbal medicines, and external therapy have also been proposed for the prevention and therapy of OSAHS. Some of these strategies are still used in current clinical practice. This review highlights historical characterizations of OSAHS and the theory of TCM and also explores its therapy in TCM, which may shed light on future OSAHS research. This is the first systematic English review of the role of TCM in the treatment of OSAHS.

Investigating predictors of treatment response in Dialectical Behavior Therapy for borderline personality disorder using LASSO regression.

OBJECTIVE: Prior studies of Dialectical Behavior Therapy (DBT) for borderline personality disorder (BPD) have yielded heterogeneous findings on what factors differentiate individuals with or without sufficient treatment response, highlighting the need for further research. METHOD: We investigated a sample of 105 individuals with BPD receiving a 6-month course of DBT. Participants were categorized as sufficient or insufficient responders using clinical and statistical change indices (based on emotion dysregulation, BPD symptom severity, utilization of DBT skills, and functional impairment). Sociodemographic, clinical severity, and treatment process factors were tested as potential predictors of treatment response using a machine learning approach (LASSO regression). RESULTS: Two cross-validated LASSO regression models predicted treatment response (AUCs > .75). They suggested that higher homework completion rate, retention in treatment, and greater baseline severity were the most important predictors of DBT treatment response indicated by BPD symptom severity and utilization of DBT skills. Favorable effects of some aspects of therapeutic alliance during initial sessions were also found. CONCLUSIONS: Future research may benefit from consolidating the criteria of treatment response, identifying clinically relevant variables, and testing the generalizability of findings to enhance knowledge of insufficient treatment response in DBT for BPD.

Toxin-Enabled "On-Demand" Liposomes for Enhanced Phototherapy to Treat and Protect against Methicillin-Resistant Staphylococcus aureus Infection.

An effective therapeutic strategy against methicillin-resistant Staphylococcus aureus (MRSA) that does not promote further drug resistance is highly desirable. While phototherapies have demonstrated considerable promise, their application toward bacterial infections can be limited by negative off-target effects to healthy cells. Here, a smart targeted nanoformulation consisting of a liquid perfluorocarbon core stabilized by a lipid membrane coating is developed. Using vancomycin as a targeting agent, the platform is capable of specifically delivering an encapsulated photosensitizer along with oxygen to sites of MRSA infection, where high concentrations of pore-forming toxins trigger on-demand payload release. Upon subsequent near-infrared irradiation, local increases in temperature and reactive oxygen species effectively kill the bacteria. Additionally, the secreted toxins that are captured by the nanoformulation can be processed by resident immune cells to promote multiantigenic immunity that protects against secondary MRSA infections. Overall, the reported approach for the on-demand release of phototherapeutic agents into sites of infection could be applied against a wide range of high-priority pathogens.

Targeted delivery of fat extract by platelet membrane-cloaked nanocarriers for the treatment of ischemic stroke.

BACKGROUND: Our previous studies suggest that human fat extract (FE) contains a variety of angiogenic factors and may provide an alternative treatment option for stroke. However, the therapeutic effect is largely limited due to its short half-life, and inaccurate targeting. RESULTS: Herein, we leverage the targeting abilities of platelets (PLTs) to the lesion area of stroke and Arg-Gly-Asp (RGD) peptides to the angiogenic blood vessels to develop a biomimetic nanocarrier that capable of delivering FE precisely to treat stroke. The biomimetic nanocarriers are comprised of FE-encapsulated PLGA (poly(lactic-co-glycolic acid)) core enclosed by RGD peptides decorated plasma membrane of PLTs, namely RGD-PLT@PLGA-FE. We found that RGD-PLT@PLGA-FE not only targeted damaged and inflamed blood vessels but also achieved rapid accumulation in the lesion area of ischemic brain. In addition, RGD-PLT@PLGA-FE kept a sustained release behavior of FE at the lesion site, effectively increased its half-life and promoted angiogenesis and neurogenesis with delivering neurotrophic factors including BDNF, GDNF and bFGF to the brain, that ultimately resulted in blood flow increase and neurobehavioral recovery. CONCLUSIONS: In conclusion, our study provides a new strategy to design a biomimetic system for FE delivery and it is a promising modality for stroke therapy.

Cooperative Self-Assembled Nanoparticle Induces Sequential Immunogenic Cell Death and Toll-Like Receptor Activation for Synergistic Chemo-immunotherapy.

Anticancer immunotherapy is hampered by poor immunogenicity and a profoundly immunosuppressive microenvironment in solid tumors and lymph nodes. Herein, sequential pH/redox-responsive nanoparticles (SRNs) are engineered to activate the immune microenvironment of tumor sites and lymph nodes. The two-modular SRNs could sequentially respond to the acidic tumor microenvironment and endosome compartments of dendritic cells (DCs) to precisely deliver doxorubicin (DOX) and imidazoquinolines (IMDQs). In the tumor microenvironment, released DOX triggers immunogenic cell death. In sentinel lymph nodes, the IMDQ nanoparticle module is dissociated in the acidic endosome compartment to specifically stimulate toll-like receptor 7/8 for DC maturation. Thus, the orchestrated nanoparticle system could enhance the infiltration of CD8α+ T cells in tumors and provoke a strong antitumor immune response toward primary and abscopal tumors in B16-OVA and CT26 tumor-bearing mice models. The cooperative self-assembled nanoparticle strategy provides a potential candidate of nanomedicine to advance the synergistic cancer chemo-immunotherapy.

Phone consultation and burnout among providers of dialectical behaviour therapy.

Adherent dialectical behaviour therapy (DBT) includes between-session phone consultation to help clients generalize skills, solve problems during crises, and repair relationships. Despite benefits of phone consultation, it is frequently not implemented in outpatient settings. The perceived burden phone consultation places on providers is one of the most frequently cited reasons for its omission. The current study examined phone consultation in relation to providers' burnout using a cross-sectional design. We hypothesized that (1) DBT experience and support from peer consultation team members, including perceived team efficacy and shared coaching responsibilities, would be associated with lower rates of burnout and (2) higher numbers of crisis contacts and "other" contacts, but not noncrisis skills generalization contacts, would be associated with increased burnout. Participants were 65 DBT therapists who completed an anonymous survey online. Results suggest that both having more effective consultation teams and sharing phone consultation among team members were associated with decreased burnout. Additionally, more crisis contacts were found to be associated with higher burnout, whereas higher number of skills generalization calls was not. This study represents an important first step towards evaluating the impact of phone consultation on providers and highlights the importance of effective peer consultation in reducing therapist burnout.

A pH-Responsive Nanoparticle Library with Precise pH Tunability by Co-Polymerization with Non-Ionizable Monomers.

Precise monitoring of the subtle pH fluctuation during biological events remains a big challenge. Previously, we reported an ultra-pH-sensitive (UPS) nanoprobe library with a sharp pH response using co-polymerization of two tertiary amine-containing monomers with distinct pKa . Currently, we have generalized the UPS nanoparticle library with tunable pH transitions (pHt ) by copolymerization of a tertiary amine-containing monomer with a series of non-ionizable monomers. The pHt of nanoparticles is fine-tuned by the non-ionizable monomers with different hydrophobicity. Each non-ionizable monomer presents a constant contribution to pH tunability regardless of tertiary amine-containing monomers. Based on this strategy, we produced two libraries of nanoprobes with continuous pHt covering the entire physiological pH range (5.0-7.4) for fluorescent imaging of endosome maturation and cancers. This generalized strategy provides a powerful toolkit for biological studies and cancer theranostics.

Gadd45b is a novel mediator of depression-like behaviors and neuroinflammation after cerebral ischemia.

BACKGROUND: Poststroke depression (PSD) is an important consequence after stroke, with a negative impact on stroke outcome. Recent evidence points to a modulatory role of Growth arrest and DNA-damage-inducible protein 45 beta (Gadd45b) in depression. Herein, we evaluated the antidepressant efficacy and mechanism underlying the potent therapeutic effects of Gadd45b after cerebral ischemia. METHODS: Adult male Sprague-Dawley rats were subjected to cerebral ischemia by permanent middle cerebral artery occlusion (MCAO). The sucrose preference test (SPT), forced swim test (FST), and tail suspension test (TST) were performed after completing MCAO to study the antidepressant-like effects. The expression of brain-derived neurotrophic factor (BDNF) and neuroinflammation were determined in the hippocampus. RESULTS: We showed that Gadd45b knockdown induced depression-like behaviors after cerebral ischemia, including increased immobility time in the FST and TST and reduced sucrose preference. Gadd45b knockdown enhanced the expression of pro-inflammatory cytokines IL-6 and TNF-α, accompanying with decreased protein levels of BDNF in the hippocampus. Moreover, the levels of phosphorylated ERK and CREB, which have been implicated in events downstream of BDNF signaling, were also decreased after cerebral ischemia. CONCLUSION: Hence, the results showed that Gadd45b is a promising drug candidate for treating PSD and possibly other nervous system diseases associated with neuroinflammation. Gadd45b may have therapeutic potential for PSD through BDNF-ERK-CREB pathway and neuroinflammation.

A distal enhancer maintaining Hoxa1 expression orchestrates retinoic acid-induced early ESCs differentiation.

Retinoic acid (RA) induces rapid differentiation of embryonic stem cells (ESCs), partly by activating expression of the transcription factor Hoxa1, which regulates downstream target genes that promote ESCs differentiation. However, mechanisms of RA-induced Hoxa1 expression and ESCs early differentiation remain largely unknown. Here, we identify a distal enhancer interacting with the Hoxa1 locus through a long-range chromatin loop. Enhancer deletion significantly inhibited expression of RA-induced Hoxa1 and endoderm master control genes such as Gata4 and Gata6. Transcriptome analysis revealed that RA-induced early ESCs differentiation was blocked in Hoxa1 enhancer knockout cells, suggesting a requirement for the enhancer. Restoration of Hoxa1 expression partly rescued expression levels of ∼40% of genes whose expression changed following enhancer deletion, and ∼18% of promoters of those rescued genes were directly bound by Hoxa1. Our data show that a distal enhancer maintains Hoxa1 expression through long-range chromatin loop and that Hoxa1 directly regulates downstream target genes expression and then orchestrates RA-induced early differentiation of ESCs. This discovery reveals mechanisms of a novel enhancer regulating RA-induced Hoxa genes expression and early ESCs differentiation.

Thyroid hormone levels and structural parameters of thyroid homeostasis are correlated with motor subtype and disease severity in euthyroid patients with Parkinson's disease.

Purpose: This study is to investigate the relationship between thyroid function and Parkinson's disease (PD).Materials and Methods: Totally 77 PD patients were included, who were divided into tremor-dominant-type (TDT), akinetic-rigid-type (ART) and mixed-type (MXT) subgroups. Parkinsonism severity and stage was assessed by modified H-Y stage. Thyroid-stimulating hormone (TSH), fT3 and fT4 levels were detected to analyze thyroid function. Parameters of thyroid homeostasis, including thyroid's secretory capacity (SPINA-GT), the total deiodinase activity (SPINA-GD) and Jostel's TSH index and the thyrotroph thyroid hormone sensitivity index (TTSI), were calculated and compared.Results: Thyroid hormone levels in PD patients were lower than normal controls. Patients with TDT/MXT had significantly higher fT4 level than those with ART. TSH levels were 1.73 ± 0.93 and 2.06 ± 1.04 ulU/ml for patients with TDT/MXT and ART, respectively. The patients in the TDT/MXT group had significantly lower SPINA-GD while significantly higher SPINA-GT than ART group. The fT3 level was significantly higher in early group than advanced group. TSH index in the early group was significantly higher than the advanced group. The fT4 level was negatively correlated with UPDRS motor score. Univariate and multivariable logistic regression analysis indicated that fT4 was positively correlated with PD motor subtype, which disappeared after adjusting for confounding factors. The fT3 level was negatively correlated with PD disease severity, even after adjusting for confounding factors. In female PD patients, fT4 level in TDT/MXT group was significantly higher than ART group. Male PD patients had higher fT4 levels in early patients than advanced patients. Percentage of patients exhibiting ART was decreased significantly in higher fT4 level subgroups. With the increase of TSH index and TTSI, the proportion of advanced PD patients gradually decreased. The proportion of PD patients with TDT/MXT motor subtype gradually increased with the quartiles of SPINA-GT.Conclusion: Thyroid hormone levels and structural parameters of thyroid homeostasis are correlated with motor subtype and disease severity in euthyroid patients with PD.

pH-Amplified CRET Nanoparticles for In Vivo Imaging of Tumor Metastatic Lymph Nodes.

Noninvasive imaging strategies have been extensively investigated for in vivo mapping of sentinel lymph nodes (SLNs). However, the current imaging strategies fail to accurately assess tumor metastatic status in SLNs with high sensitivity. Here we report pH-amplified self-illuminating near-infrared nanoparticles, which integrate chemiluminescence resonance energy transfer (CRET) and signal amplification strategy, enabling accurate identification of metastatic SLNs. After draining into lymph nodes, the nanoparticles were phagocytosed and dissociated in acidic phagosomes of inflammatory macrophages to emit near-infrared luminescent light. Using these nanoparticles, we successfully differentiated tumor metastatic lymph nodes from benign ones. These nanoparticles also exhibited excellent imaging capability for early detection of metastatic SLNs in diverse animal tumor models with small tumor volume (100-200 mm3 ).

PCAT-1 promotes cell growth by sponging miR-129 via MAP3K7/NF-κB pathway in multiple myeloma.

Loss of one or some specific miRNA-mediated regulation is closely associated with malignant progression of multiple myeloma (MM). But how these miRNAs work and what role the specific miRNA plays in this process of malignant progression remain unclear. It was found in this study that the expression of miR-129 was decreased in both MM cell lines and newly diagnosed MM patients. Further clinicopathological statistics showed that miR-129 was correlated with the isotype of MM patients. MiR-129 overexpression disturbed cell proliferation, cell cycle evolution and spurred apoptosis both in vitro and in vivo. MAP3K7, a kinase able to activate NF-κB circuit, was found to be up-regulated in MM and contain a binding target of miR-129. In addition, lncRNA PCAT-1 functioned to sponge miR-129 and thereby lowered its expression. PCAT-1 knockdown eliminated the tumour-promoting effect caused by miR-129 inhibition, probably through repressing MAP3K7 and subsequent NF-κB activation. To the best of our knowledge, this is the first study to have discovered that increased expression of PCAT-1 could augment cell proliferation and cycle procession and inhibit apoptosis by down-regulating miR-129 via the MAP3K7/NF-κB pathway in MM.

ß2 -adrenergic receptor signaling drives prostate cancer progression by targeting the Sonic hedgehog-Gli1 signaling activation.

BACKGROUND: Considerable evidence suggests that the sympathetic nervous system, mainly via adrenergic signaling, contributes to prostate cancer (PCa) progression. However, the underlying molecular mechanisms remain unknown. METHODS: The expression level of ß2 -adrenergic receptor (ß2 -AR) in tissue microarray was evaluated by immunohistochemistry. The effects of isoproterenol (ISO) or Sonic Hedgehog (Shh) signaling inhibitor on tumor growth were analyzed in proliferation and colony formation assays. The apoptosis of cells was analyzed by flow cytometry. Small hairpin RNA-based knockdown of ß2 -AR or Gli1 was validated by Western blot analysis and real-time PCR. Effects of ß2 -AR on prostate carcinogenesis in vivo were observed in a mouse xenograft model. The expression levels of the indicated proteins in xenograft tissues were evaluated by immunohistochemistry. Expression levels of Shh signaling components and downstream proteins were assessed by immunoblotting. RESULTS: We determined that ß2 -AR was expressed at significantly higher levels in carcinoma than in normal prostate tissues. ß2 -AR signaling also played an essential role in sustaining PCa cell proliferation in vivo and in vitro. We also found that inhibition of Shh signaling or knockdown of Gli1 expression significantly restrained ISO-induced cell proliferation in vitro. ISO alleviated the apoptosis induced by suppressing or knocking down of Gli1. The ß2 -AR agonist ISO upregulated the transcription and protein expression of target genes of Shh signaling, including c-Myc, Cyclin D1, and VEGFA. Conversely, knocking down ß2 -AR markedly suppressed the expression of Shh components in vivo and in vitro. In Gli1 knockdown cells, ISO failed to increase the expression of target genes of Shh signaling. CONCLUSIONS: In this study, we uncovered an important role of ß2 -AR signaling in regulating the Shh pathway activity in PCa tumorigenesis and provide further insight into the mechanism of the involvement of the Hh signaling pathway. Furthermore, given the efficacy of ß2 -adrenergic modulation on PCa, our study might also add evidence for potential therapeutic options of ß-blockers for PCa.

Long non-coding RNA CCAT2 as a potential serum biomarker for diagnosis and prognosis of multiple myeloma.

Increasing knowledge of long non-coding RNAs (lncRNAs) has shown that they can be used as circulating tumor markers. Also, considerable evidences have revealed that lncRNAs have important roles in tumor diagnosis and prognosis. The lncRNA CCAT2 has manifested its carcinogenic effect in a variety of tumors, but the serum expression level and clinical value in multiple myeloma (MM) remain to be explored. In our study, the expression of lncRNA CCAT2 is upregulated in the serum and bone marrow of MM patients by using quantitative real-time polymerase chain reaction (qRT-PCR). The high expression level of CCAT2 in the serum of MM patients correlated with International Scoring System (ISS) stages, renal dysfunction, serum ß2-microglobulin (ß2-MG) concentration, and light chain (κ and λ) concentrations. Area under the curve (AUC) of CCAT2 in serum is 0.899. Besides, the sensitivity and specificity were 85.80% and 83%, respectively. Furthermore, combination of CCAT2, IgA, HGB, and ß2-MG significantly improved the MM diagnostic sensitivity and AUC. Here, our present investigation indicates that serum circulating CCAT2 may serve as a potential tumor marker for diagnosis and prognosis of MM.

User Experience Affects Dropout from Internet-Delivered Dialectical Behavior Therapy.

Background: The emergence of computerized treatment may help reduce the gap between mental health treatment needs and accessibility, but unfortunately, dropout from these interventions is often high. Introduction: To increase the effectiveness of computerized interventions and reduce dropout, particularly among high-risk and clinically complex populations, better understanding of how usable and acceptable (i.e., user experience) these interventions are, informed by human computer interaction research, is needed. This study examines user experience of internet-delivered dialectical behavior therapy (iDBT). The major aim is to explore whether treatment dropout was affected by the complexity of population and/or user experience. Methods: Secondary analyses were conducted using data from a randomized controlled trial that evaluated iDBT in a sample of 59 suicidal and heavy episodic drinkers. Multivariate logistic regression and chi-square tests were performed to examine the roles of clinical characteristics and user experience in differentiating dropouts and nondropouts. Results: The only significant pretreatment predictor of dropout was the presence of a barrier, with technological and unknown barriers being most strongly associated with dropping. No clinical characteristics emerged as significant predictors of dropout. Discussion: The current results highlight technological problems as a possible barrier to adherence to computerized interventions. Future research would profit from increased integration of human-computer interaction to identify and solve user experience problems.

ncRNAs associated with drug resistance and the therapy of digestive system neoplasms.

Digestive system cancer remains a common cancer and the main cause of cancer-related death worldwide. Drug resistance is a major challenge in the therapy of digestive system cancer, and represents a primary obstacle in the treatment of cancer by restricting the efficiency of both traditional chemotherapy and biological therapies. Existing studies indicate that noncoding RNAs play an important role in the evolution and progression of drug resistance in digestive system cancer, mainly by modulating drug transporter-related proteins, DNA damage repair, cell-cycle-related proteins, cell apoptosis-related proteins, drug target-related proteins, and the tumor microenvironment. In this review, we address the potential mechanisms of ncRNAs underlying drug resistance in digestive system tumors and discuss the possible application of ncRNAs against drug resistance in digestive system tumors.

Ultra-pH-sensitive indocyanine green-conjugated nanoprobes for fluorescence imaging-guided photothermal cancer therapy.

Photothermal therapy (PTT) has been recognized as a promising approach for cancer treatment due to its minimal invasiveness and low systemic side effects. However, developing a photothermal agent with accurate tumor imaging capability is a prerequisite for the efficient PTT. Here, we developed a series of ultra-pH-sensitive indocyanine green (ICG)-conjugated nanoparticles for fluorescence imaging-guided tumor PTT. These nanoparticles exhibited high fluorescence activation ratio (~100-fold) with sharp pH transition (ΔpHon/off <0.25), and superior temperature response than free ICG. The in vivo imaging experiments demonstrated that the nanoparticles generated excellent tumor-to-normal tissue contrast through pH-triggered fluorescence activation in tumor sites, which provided information on tumor mass location, boundaries, and shape. Moreover, comparing to free ICG, the nanosystem had significantly longer blood circulation time and more accurate tumor targeting, providing efficient photothermal therapeutic effect against A549 tumor in living animals. In conclusion, this nanoplatform offers a potential strategy for imaging-guided cancer PTT.