Synthesis of a Metalla[2]catenane, Metallarectangles and Polynuclear Assemblies from Di(N-Heterocyclic Carbene) Ligands.

The 2,7-fluorenone-linked bis(6-imidazo[1,5-a]pyridinium) salt H2-1(PF6)2 reacts with Ag2O in CH3CN to yield the [2]catenane [Ag4(1)4](PF6)4. The [2]catenane rearranges in DMF to yield two metallamacrocycles [Ag2(1)2](PF6)2. 2,7-Fluorenone-bridged bis-(imidazolium) salt H2-L(PF6)2 (L = 2a, 2b) react with Ag2O in CH3CN to yield metallamacrocycles [Ag2(L)2](PF6)2 with interplanar distances between the fluorenone rings too small for [2]catenane formation. Intra- and intermolecular p···p interactions between the fluorenone groups were observed by X-ray crystallography. The strongly kinked 2,7-fluorenone bridged bis(5-imidazo[1,5-a]pyridinium) salt H2-4(PF6)2 reacts with Ag2O to yield [Ag2(4)(CN)](PF6) while the tetranuclear assembly [Ag4(4)2(CO3)](PF6)2 was obtained in the presence of K2CO3.

An international, multicenter, survey-based analysis of practice and management of acute liver failure.

Acute liver failure (ALF) is an acute liver dysfunction with coagulopathy and HE in a patient with no known liver disease. As ALF is rare and large clinical trials are lacking, the level of evidence regarding its management is low-moderate, favoring heterogeneous clinical practice. In this international multicenter survey study, we aimed to investigate the current practice and management of patients with ALF. An online survey targeting physicians who care for patients with ALF was developed by the International Liver Transplantation Society ALF Special-Interest Group. The survey focused on the management and liver transplantation (LT) practices of ALF. Survey questions were summarized overall and by geographic region. A total of 267 physicians completed the survey, with a survey response rate of 21.36%. Centers from all continents were represented. More than 90% of physicians specialized in either transplant hepatology/surgery or anesthesiology/critical care. Two hundred fifty-two (94.4%) respondents' institutions offered LT. A total of 76.8% of respondents' centers had a dedicated liver-intensive or transplant-intensive care unit ( p < 0.001). The median time to LT was within 48 hours in 12.7% of respondents' centers, 72 hours in 35.6%, 1 week in 37.6%, and more than 1 week in 9.6% ( p < 0.001). Deceased donor liver graft (49.6%) was the most common type of graft offered. For consideration of LT, 84.8% of physicians used King's College Criteria, and 41.6% used Clichy Criteria. Significant differences were observed between Asia, Europe, and North America for offering LT, number of LTs performed, volume of patients with ALF, admission to a dedicated intensive care unit, median time to LT, type of liver graft, monitoring HE and intracranial pressure, management of coagulopathy, and utilization of different criteria for LT. In our study, we observed significant geographic differences in the practice and management of ALF. As ALF is rare, multicenter studies are valuable for identifying global practice.

Favorable Outcomes of Liver Transplantation for Hepatopulmonary Syndrome.

BACKGROUND: Hepatopulmonary syndrome (HPS) is a pulmonary vascular complication of chronic liver disease, which develops insidiously as a result of chronic liver disease. The prognosis for untreated patients with HPS is extremely poor, and liver transplantation (LT) serves as the only effective means for treating this condition. Here, we performed a retrospective analysis to evaluate the efficacy of LT on the survival and long-term prognosis of patients with HPS. METHODS: Clinical data, including survival and postoperative efficacy, from patients with HPS from records as obtained over the period from January 1 to December 31, 2022. All records were from a waiting list for LT at the Beijing Friendship Hospital Affiliated with Capital Medical University. RESULTS: Among the 274 patients on the LT waiting list, 37 were diagnosed with HPS (13.50%) and were enrolled. Survival rates of patients with HPS receiving an LT were greater, whereas a statistically significant difference was obtained between patients with LT vs non-LT with moderate to severe HPS (P = .003). The overall time until death without LT was 4-72 days after their initial HPS diagnosis. Patients with HPS receiving an LT showed a significant improvement in the state of oxygenation after surgery (P = .001). CONCLUSION: Comprehensive preoperative screening of patients on the waiting list for LT is critical to identify those patients with HPS who would maximally benefit from LT. Survival rates of patients with moderate to severe HPS are significantly increased after LT, a procedure that should be performed as soon as possible in these patients with HPS.

Updated epithelial barrier dysfunction in chronic rhinosinusitis: Targeting pathophysiology and treatment response of tight junctions.

Tight junction (TJ) proteins establish a physical barrier between epithelial cells, playing a crucial role in maintaining tissue homeostasis by safeguarding host tissues against pathogens, allergens, antigens, irritants, etc. Recently, an increasing number of studies have demonstrated that abnormal expression of TJs plays an essential role in the development and progression of inflammatory airway diseases, including chronic obstructive pulmonary disease, asthma, allergic rhinitis, and chronic rhinosinusitis (CRS) with or without nasal polyps. Among them, CRS with nasal polyps is a prevalent chronic inflammatory disease that affects the nasal cavity and paranasal sinuses, leading to a poor prognosis and significantly impacting patients' quality of life. Its pathogenesis primarily involves dysfunction of the nasal epithelial barrier, impaired mucociliary clearance, disordered immune response, and excessive tissue remodeling. Numerous studies have elucidated the pivotal role of TJs in both the pathogenesis and response to traditional therapies in CRS. We therefore to review and discuss potential factors contributing to impair and repair of TJs in the nasal epithelium based on their structure, function, and formation process.

Long-term clinical outcomes and health-related quality of life in patients with isolated methylmalonic acidemia after liver transplantation: experience from the largest cohort study in China.

BACKGROUND: Liver transplantation (LT) has been proposed as a viable treatment option for selected methylmalonic acidemia (MMA) patients. However, there are still controversies regarding the therapeutic value of LT for MMA. The systematic assessment of health-related quality of life (HRQoL)-targeted MMA children before and after LT is also undetermined. This study aimed to comprehensively assess the long-term impact of LT on MMA, including multiorgan sequelae and HRQoL in children and families. METHODS: We retrospectively evaluated 15 isolated MMA patients undergoing LT at our institution between June 2013 and March 2022. Pre- and post-transplant data were compared, including metabolic profiles, neurologic consequences, growth parameters, and HRQoL. To further assess the characteristics of the HRQoL outcomes in MMA, we compared the results with those of children with biliary atresia (BA). RESULTS: All patients had early onset MMA, and underwent LT at a mean age of 4.3 years. During 1.3-8.2 years of follow-up, the patient and graft survival rates were 100%. Metabolic stability was achieved in all patients with liberalized dietary protein intake. There was a significant overall improvement in height Z scores (P = 0.0047), and some preexisting neurological complications remained stable or even improved after LT. On the Pediatric Quality of Life Inventory (PedsQL™) generic core scales, the mean total, physical health, and psychosocial health scores improved significantly posttransplant (P < 0.05). In the family impact module, higher mean scores were noted for all subscales post-LT, especially family function and daily activities (P < 0.01). However, the total scores on the generic core scales and transplant module were significantly lower (Cohen's d = 0.57-1.17) when compared with BA recipients. In particular, social and school functioning (Cohen's d = 0.86-1.76), treatment anxiety, and communication (Cohen's d = 0.99-1.81) were far behind, with a large effect size. CONCLUSIONS: This large single-center study of the mainland of China showed an overall favorable impact of LT on isolated MMA in terms of long-term survival, metabolic control, and HRQoL in children and families. The potential for persistent neurocognitive impairment and inherent metabolic fragility requires long-term special care. Video Abstract (MP4 153780 KB).

Epithelial Tight Junction Anomalies in Nasal Inverted Papilloma.

OBJECTIVES: As a critical component of the epithelial barrier, tight junctions (TJs) are essential in nasal mucosa against pathogen invasion. However, the function of TJs has rarely been reported in nasal inverted papilloma (NIP). This study aims to investigate the potential factors of TJs' abnormality in NIP. METHODS: We assessed the expression of ZO-1, occludin, claudin-1, claudin-3, and claudin-7 in healthy controls and NIP by real-time quantitative polymerase chain reaction and immunofluorescent staining. The correlation between TJs expression and neutrophil count, TH 1/TH 2/TH 17 and regulatory T cell biomarkers, and the proportion of nasal epithelial cells was investigated. RESULTS: Upregulation of ZO-1, occludin, claudin-1, and claudin-7, along with downregulation of claudin-3, was found in NIP compared to control (all p < 0.05). An abnormal proportion with a lower number of ciliated cells (control vs. NIP: 37.60 vs. 8.67) and goblet cells (12.52 vs. 0.33) together with a higher number of basal cells (45.58 vs. 124.00) in NIP. Meanwhile, claudin-3 was positively correlated with ciliated and goblet cells (all p < 0.01). Additionally, neutrophils were excessively infiltrated in NIP, negatively correlated with ZO-1, but positively with claudin-3 (all p < 0.05). Furthermore, FOXP3, IL-10, TGF-ß1, IL-5, IL-13, and IL-22 levels were induced in NIP (all p < 0.01). Occludin level was negatively correlated with IL-10, IL-5, IL-13, and IL-22, whereas ZO-1 was positively with TGF-ß1 (all p < 0.05). CONCLUSION: Nasal epithelial barrier dysfunction with TJs anomalies is commonly associated with abnormal proliferation and differentiation of epithelial cells and imbalance of immune and inflammatory patterns in NIP. LEVEL OF EVIDENCE: NA Laryngoscope, 134:552-561, 2024.

Unravelling the Roles of Solvophobic Effects and π⋠⋠⋠π Stacking Interactions in the Formation of [2]Catenanes Featuring Di-(N-Heterocyclic Carbene) Building Blocks.

A series of [2]catenanes has been prepared from di-NHC building blocks by utilizing solvophobic effects and/or π⋅⋅⋅π stacking interactions. The dinickel naphthobiscarbene complex syn-[1] and the kinked biphenyl-bridged bipyridyl ligand L2 yield the [2]catenane [2-IL](OTf)4 by self-assembly. Solvophobic effects are pivotal for the formation of the interlocked species. Substitution of the biphenyl-linker in L2 for a pyromellitic diimide group gave ligand L3 , which yielded in combination with syn-[1] the [2]catenane [3-IL](OTf)4 . This assembly exhibits enhanced stability in diluted solution, aided by additional π⋅⋅⋅π stacking interactions. The π⋅⋅⋅π stacking was augmented by the introduction of a pyrene bridge between two NHC donors in ligand L4 . Di-NHC precursor H2 -L4 (PF6 )2 reacts with Ag2 O to give the [Ag2 L4 2 ]2 [2]catenane [4-IL](PF6 )4 , which shows strong π⋅⋅⋅π stacking interactions between the pyrene groups. This assembly was readily converted into the [Au2 L4 2 ]2 gold species [5-IL](PF6 )4 , which exhibits exceptional stability based on the strong π⋅⋅⋅π stacking interactions and the enhanced stability of the Au-CNHC bonds.

Anesthesia and Critical Care for the Prediction and Prevention for Small-for-size Syndrome: Guidelines from the ILTS-iLDLT-LTSI Consensus Conference.

BACKGROUND: During the perioperative period of living donor liver transplantation, anesthesiologists and intensivists may encounter patients in receipt of small grafts that puts them at risk of developing small for size syndrome (SFSS). METHODS: A scientific committee (106 members from 21 countries) performed an extensive literature review on aspects of SFSS with proposed recommendations. Recommendations underwent a blinded review by an independent expert panel and discussion/voting on the recommendations occurred at a consensus conference organized by the International Liver Transplantation Society, International Living Donor Liver Transplantation Group, and Liver Transplantation Society of India. RESULTS: It was determined that centers with experience in living donor liver transplantation should utilize potential small for size grafts. Higher risk recipients with sarcopenia, cardiopulmonary, and renal dysfunction should receive small for size grafts with caution. In the intraoperative phase, a restrictive fluid strategy should be considered along with routine use of cardiac output monitoring, as well as use of pharmacologic portal flow modulation when appropriate. Postoperatively, these patients can be considered for enhanced recovery and should receive proactive monitoring for SFSS, nutrition optimization, infection prevention, and consideration for early renal replacement therapy for avoidance of graft congestion. CONCLUSIONS: Our recommendations provide a framework for the optimal anesthetic and critical care management in the perioperative period for patients with grafts that put them at risk of developing SFSS. There is a significant limitation in the level of evidence for most recommendations. This statement aims to provide guidance for future research in the perioperative management of SFSS.

The P1 protein of wheat yellow mosaic virus exerts RNA silencing suppression activity to facilitate virus infection in wheat plants.

Wheat yellow mosaic virus (WYMV) causes severe wheat viral disease in Asia. However, the viral suppressor of RNA silencing (VSR) encoded by WYMV has not been identified. Here, the P1 protein encoded by WYMV RNA2 was shown to suppress RNA silencing in Nicotiana benthamiana. Mutagenesis assays revealed that the alanine substitution mutant G175A of P1 abolished VSR activity and mutant Y10A VSR activity remained only in younger leaves. P1, but not G175A, interacted with gene silencing-related protein, N. benthamiana calmodulin-like protein (NbCaM), and calmodulin-binding transcription activator 3 (NbCAMTA3), and Y10A interacted with NbCAMTA3 only. Competitive Bimolecular fluorescence complementation and co-immunoprecipitation assays showed that the ability of P1 disturbing the interaction between NbCaM and NbCAMTA3 was stronger than Y10A, Y10A was stronger than G175A. In vitro transcript inoculation of infectious WYMV clones further demonstrated that VSR-defective mutants G175A and Y10A reduced WYMV infection in wheat (Triticum aestivum L.), G175A had a more significant effect on virus accumulation in upper leaves of wheat than Y10A. Moreover, RNA silencing, temperature, and autophagy have significant effects on the accumulation of P1 in N. benthamiana. Taken together, WYMV P1 acts as VSR by interfering with calmodulin-associated antiviral RNAi defense to facilitate virus infection in wheat, which has provided clear insights into the function of P1 in the process of WYMV infection.

Impact of immunosuppression level on liver allograft fibrosis after pediatric liver transplantation: a retrospective cohort study.

BACKGROUND: Liver allograft fibrosis (LAF) is prevalent among children with long-term survival after liver transplantation (LT). The authors aimed to identify clinical risk factors, with a focus on the impact of immunosuppression (IS) level in the early post-transplant period on LAF. METHODS: A retrospective study was conducted on pediatric LT recipients with at least 1-year of follow-up. Cox regression models were used to analyze risk factors associated with LAF, and landmark analysis was used to evaluate the impact of IS level on LAF. Longitudinal analysis was also conducted in patients with paired biopsies. RESULTS: A total of 139 patients involving 174 liver biopsies were included. With 2.3 to 5.9 years of follow-up, LAF was detected in 91.4% of patients (7.9% were significant), up to 88.2% of whom showed normal liver function. Episodes of acute rejection, biliary complications, cytomegalovirus infection, and prolonged cold ischemia time were independent risk factors. Besides, the risk of LAF in patients with relatively low IS levels at postoperative 1-3, 3-6, 6-12, and 12-36 months was higher than the counterparts. Especially, in patients with relatively high IS levels (mean tacrolimus trough concentration ≥5.1 ng/ml) during postoperative 12-36 months, the risk of LAF was 67% lower in the short future ( P =0.006). In paired analysis, patients with increased IS levels were more likely to achieve fibrosis-reduction (HR=7.53, P =0.025). CONCLUSIONS: Mild to moderate LAF is common among pediatric LT recipients and can appear early and silently. Maintaining adequate levels of IS during 1-3 years after LT seems crucial to ensure protection against LAF.

Impact of pure laparoscopic surgery on bile duct division of living donor left lateral section procurement.

Background: Although laparoscopic living donor left lateral section liver procurements represents an established and safe procedure, there remains much discussion on this topic. In particular, the issue of whether laparoscopic living donor liver procurement increases the difficulty of the surgery and potential complications for recipients continue to confound experts in this field. Methods: In this report, data from 180 cases of living donor left lateral section liver transplantation patients were analyzed retrospectively. Of these 180 cases, 106 grafts were procured by open surgery and 74 by pure laparoscopic surgery. Results: While surgery durations and blood loss were decreased in donors from the laparoscopic surgery group, increased biliary openings of grafts and relatively high peak aspartate aminotransferase (AST) levels were present in both donors and recipients with this procedure. Conclusions: Laparoscopic living donor left lateral section liver procurement represents a safe and effective procedure for both donors and recipients. However, laparoscopic surgery can more frequently lead to multiple biliary tracts in the graft and its impact on the prognosis of recipients remains uncertain. Use of routine X-ray based intraoperative cholangiography may help to reduce this problem.

Predictive Significance of Claudin-3 for Epithelial Barrier Dysfunction in Chronic Rhinosinusitis With Nasal Polyps.

PURPOSE: The abnormal expression of tight junction (TJ) plays a vital role in the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP). However, there is no appropriate tool to distinguish and diagnose epithelial barrier defects in clinical practice. This study aimed to evaluate the predictive value of claudin-3 for epithelial barrier dysfunction in CRSwNP. METHODS: In this study, TJ protein levels were evaluated by real-time quantitative polymerase chain reaction, immunofluorescent, and immunohistochemistry staining in control subjects and CRSwNP patients. The receiver operating characteristic (ROC) curve was created to assess the predictive value of TJ breakdown in clinical outcomes. In vitro, human nasal epithelial cells were cultured at the air-liquid interface to analyze the transepithelial electrical resistance (TER) level. RESULTS: The expression levels of occludin, tricellulin, claudin-3, and claudin-10 were decreased (all P < 0.05), and those of claudin-1 was increased (P < 0.05) in CRSwNP patients as compared to healthy subjects. Additionally, claudin-3 and occludin levels were negatively correlated with the computed tomography score in CRSwNP (all P < 0.05), and the ROC curve indicated that the claudin-3 level had the most predictive accuracy in evaluating epithelial barrier disruption (area under the curve = 0.791, P < 0.001). Finally, the time-series analysis showed the highest correlation coefficient between TER and claudin-3 (cross-correlation function = 0.75). CONCLUSION: In this study, we suggest that claudin-3 could be a valuable biomarker for predicting nasal epithelial barrier defects and disease severity in CRSwNP.

[Evaluation of the efficacy of Nd:YAG laser in the treatment of 80 patients with oral mucosal venous malformation].

PURPOSE: To evaluate the efficacy of Nd:YAG laser treatment for venous malformations. METHODS: Eighty patients with oral mucosal venous malformations underwent one or more Nd:YAG laser treatments, and photographs of the lesions before and after laser treatment were collected and compared, patients' satisfaction were assessed using visual analog scale (VAS). SPSS 22.0 software package was used for data analysis. RESULTS: A total of 58 cases were cured in 80 patients, 21 cases showed remarkable improvement. Nine patients(11.25%) experienced adverse effects after laser therapy, including atrophic scars in 2 patients, oral mucosal ulcers in 4 patients, transient hyperpigmentation in 2 patients, and transient hypopigmentation in 1 patient, which met the expected response to effective therapy, and the follow-up results showed that most patients achieved maximum satisfaction values. CONCLUSIONS: Nd:YAG laser is an effective and safe treatment for oral mucosal venous malformation with definite efficacy and few side effects, which is worthy of popularization and application.

Outcomes from a Single Transplant Center of 5 Pediatric Cases of Domino Liver Transplantation from Live Donors with Maple Syrup Urine Disease.

BACKGROUND Maple syrup urine disease (MSUD) is a rare genetic deficiency of the branched-chain alpha-keto acid dehydrogenase (BCKAD) complex that breaks down amino acids, resulting in multi-organ failure. This report is of 5 pediatric cases of domino liver transplantation (DLT) from live donors with MSUD from a single transplant center in Beijing. CASE REPORT All MSUD donors were confirmed to have disease-causing mutations in BCKDHA (branched-chain keto acid dehydrogenase E1, alpha polypeptide) or BCKDHB (branched-chain keto acid dehydrogenase E1, ß polypeptide) genes by peripheral blood whole-exon sequencing. Serum leucine and valine concentrations were significantly higher than normal values. Recipients ranged in age from 0.75 to 9 years old. Three patients underwent auxiliary liver transplantation, and the other children all underwent liver or partial liver transplantation. This case report was followed up for 25 to 79 months. The prognosis, growth, and development of patients were followed up. By the end of the last follow-up, all children had survived. All patients had normal serum leucine and valine concentrations after surgery. In case 1, portal vein stenosis post-operatively. In case 2, stenosis of hepatic artery and bile duct occurred. In case 5, hepatic artery and portal vein stenosis occurred, resulting in graft loss.   CONCLUSIONS The findings from our center support the findings from other pediatric liver transplant centers that liver transplantation using MSUD donors can have successful outcomes without the development of MSUD in the recipient.

Prophylactic terlipressin infusion for severe postreperfusion syndrome in patients undergoing deceased donor liver transplantation: the TIPS-DDLT randomized controlled trial.

BACKGROUND: Severe postreperfusion syndrome (PRS) is a critical and potentially catastrophic event during deceased donor liver transplantation (LT). Terlipressin has been widely used as a renoprotective agent during the perioperative period of LT. This study was designed to evaluate whether prophylactic terlipressin would reduce the occurrence of severe PRS in deceased donor LT. METHODS: In this single-center, randomized, double-blind trial, we randomly assigned adults who underwent deceased donor LT to receive 1 mg of terlipressin or placebo immediately after portal vein (PV) clamping. The primary outcome was the incidence of severe PRS after PV declamping, defined according to hypotension-based criteria per the Peking criteria. RESULTS: Between March 2019 and January 2021, we enrolled 64 patients and randomly assigned 32 to the terlipressin group and 32 to the control group. Severe PRS was significantly less frequent in the terlipressin group than in the control group (9.4 vs. 53.1%; OR, 0.09; 95% CI, 0.02-0.36; P <0.001). The vasopressor requirements for inferior vena cava clamping and severe PRS were significantly reduced by the intervention compared to controls (all P <0.01). Prophylactic terlipressin stabilized the mean arterial pressure ( P =0.001) and heart rate ( P =0.040) at 30 min after anhepatic phase but increased the pulmonary capillary wedge pressure (PCWP) at 5 min after reperfusion ( P =0.003). Patients in the terlipressin group had a decreased right PV flow velocity following reperfusion ( P =0.001), a longer postoperative mechanical ventilation time ( P =0.029), a lower initial poor graft function rate ( P =0.012), and lower peak alanine transaminase levels ( P =0.032) after transplantation. CONCLUSION: The prophylactic use of terlipressin reduces the incidence of severe PRS in deceased donor LT. However, concerns remain regarding elevated PCWP.

Effect of liver transplantation with primary hyperoxaluria type 1: Five case reports and review of literature.

BACKGROUND: Primary hyperoxaluria type 1 (PH1) is a rare autosomal recessive disease stemming from a deficiency in liver-specific alanine-glyoxylate aminotransferase, resulting in increased endogenous oxalate deposition and end-stage renal disease. Organ transplantation is the only effective treatment. However, its approach and timing remain controversial. CASE SUMMARY: We retrospectively analyzed 5 patients diagnosed with PH1 from the Liver Transplant Center of the Beijing Friendship Hospital from March 2017 to December 2020. Our cohort included 4 males and 1 female. The median age at onset was 4.0 years (range: 1.0-5.0), age at diagnosis was 12.2 years (range: 6.7-23.5), age at liver transplantation (LT) was 12.2 years (range: 7.0-25.1), and the follow-up time was 26.3 mo (range: 12.8-40.1). All patients had delayed diagnosis, and 3 patients had progressed to end-stage renal disease by the time they were diagnosed. Two patients received preemptive LT; their estimated glomerular filtration rate was maintained at > 120 mL/min/1.73 m2, indicating a better prognosis. Three patients received sequential liver and kidney transplantation. After transplantation, serum and urinary oxalate decreased, and liver function recovered. At the last follow-up, the estimated glomerular filtration rates of the latter 3 patients were 179, 52 and 21 mL/min/1.73 m2. CONCLUSION: Different transplantation strategies should be adopted for patients based on their renal function stage. Preemptive-LT offers a good therapeutic approach for PH1.

Construction and Hierarchical Self-Assembly of Multifunctional Coordination Cages with Triangular Metal-Metal-Bonded Units.

Herein, a series of face-capped (Tr2M3)4L4 (Tr = cycloheptatrienyl cationic ring; M = metal; L = organosulfur ligand) tetrahedral cages 1-3 functionalized with 12 appended crown ether moieties were designed and synthesized. The reversible binding of ammonium cations with peripheral crown ether moieties to adjust internal guest-binding was realized. Combination of a bisammonium linker and cage 3 led to the formation of a supramolecular gel SPN1 via host-guest interactions between the crown ether moieties and ammonium salts. The obtained supramolecular gel exhibited multiple-stimuli responsiveness, injectability, and excellent self-healing properties and could be further developed to a SPN1-based drug delivery system. In addition, the storage modulus of SPN1 was 20 times higher than that of the model gel without Pd-Pd bonded blocks, and SPN1 had better self-healing properties compared with the latter, demonstrating the importance of such cages in improving mechanical strength without losing the dynamic properties of the material. The cytotoxicity in vitro of the drug-loaded (doxorubicin or methotrexate) SPN1 was significantly improved compared to that of free drugs.

Synthesis of triarylborane-centered N-heterocyclic carbene cages with tunable photophysical properties.

Triarylborane-based discrete metal-carbene supramolecular cages [M3(1)2](PF6)3 (M = Ag, Au) were synthesized and characterized. The new hexacarbene assemblies show a significant solvatochromic effect in solvents of different polarity. Furthermore, the reversible fluoride binding property of [Au3(1)2](PF6)3 was investigated by UV-vis absorption and fluorescence titrations. This work holds promise for future developments in the area of highly emissive and stimulus-responsive NHC-metal assemblies.

Solvato-Controlled Assembly and Structural Transformation of Emissive Poly-NHC-Based Organometallic Cages and Their Applications in Amino Acid Sensing and Fluorescence Imaging.

Stimuli-induced structural transformation of supramolecular cages has drawn increasing attention because of their sensitive feature to external variations as model systems to simulate biological processes. However, combining structural transformation and useful functions has remained a difficult task. This study reports the solvato-controlled self-assembly of two unique topologies with different emission characteristics, a water-soluble Ag8 L4 cage (A) and an Ag4 L2 cage (B), produced from the same sulfonate-pendant tetraphenylethene (TPE) bridged tetrakis-(1,2,4-triazolium) ligand. Both cages show interesting solvent-responsive reversible structural transformation, and the change of fluorescence signals can efficiently track the process. Additionally, water-soluble cage A exhibits unique properties in thermochromism, thiol amino acid sensing, and subcellular imaging in aqueous media.