Microwave ablation versus laparoscopic resection for hepatocellular carcinoma in patients with clinically significant portal hypertension: a propensity score-matched study of postoperative liver decompensation.

OBJECTIVES: The study of postoperative liver decompensation after microwave ablation (MWA) for hepatocellular carcinoma (HCC) in patients with clinically significant portal hypertension (CSPH) is still lacking. The purpose of the present study was to compare the postoperative liver decompensation after MWA and laparoscopic resection (LR) for HCC in patients with CSPH. METHODS: The present retrospective study enrolled 222 HCC patients with CSPH who underwent MWA (n = 67) or LR (n = 155). Postoperative liver decompensation, complications, postoperative hospital stays, and overall survival were analyzed. Factors associated with postoperative liver decompensation were identified. RESULTS: After propensity score matching, the postoperative liver decompensation rate was significantly lower in the MWA group than that in the LR group (15.5% versus 32.8%, p = 0.030). The multivariable regression analysis identified that type of treatment (MWA vs. LR, odds ratio [OR] 0.44; 95% confidence interval [CI], 0.21-0.91; p = 0.026) and Child-Pugh B (OR, 2.86; 95% CI, 1.24-6.61; p = 0.014) were independent predictors for postoperative liver decompensation. The rate of complications for patients in the MWA group was significantly lower than that in the LR group (p < 0.001). And MWA showed shorter postoperative hospital stays than LR (3 days vs. 6 days, p < 0.001). Overall survival rate between the two groups was not significantly different (p = 0.163). CONCLUSION: Compared with laparoscopic resection, microwave ablation has a lower rate of postoperative liver decompensation and might be a better option for HCC patients with CSPH. CLINICAL RELEVANCE STATEMENT: Microwave ablation exhibited a lower incidence of postoperative liver decompensation in comparison to laparoscopic resection, thereby conferring greater advantages to hepatocellular carcinoma patients with clinically significant portal hypertension. KEY POINTS: •Postoperative liver decompensation rate after microwave ablation was lower than that of laparoscopic resection for hepatocellular carcinoma in patients with clinically significant portal hypertension. •Microwave ablation showed shorter postoperative hospital stays than laparoscopic resection. •Microwave ablation had fewer complications than laparoscopic resection.

Microwave ablation versus radiofrequency ablation as bridge therapy in potentially transplantable patients with single HCC ≤ 3 cm: A propensity score-matched study.

OBJECTIVES: The efficacy of microwave ablation (MWA) for hepatocellular carcinoma (HCC) as bridge therapy has been gradually confirmed. We aimed to compare the recurrence beyond the Milan criteria (RBM) rates in potentially transplantable patients with HCC receiving MWA or radiofrequency ablation (RFA) as bridge therapy. METHODS: In total, 307 potentially transplantable patients with single HCC ≤ 3 cm who initially received MWA (n = 82) or RFA (n = 225) were included. RBM, recurrence-free survival (RFS), and overall survival (OS) were compared between MWA and RFA groups by using propensity score matching (PSM). Competing risks Cox regression was used to identify predictors of RBM. RESULTS: After PSM, the 1-, 3-, and 5-year cumulative RBM rates were 6.8%, 18.3%, and 39.3% in the MWA group (n = 75), and 7.4%,18.5%, and 27.7% in the RFA group (n = 137), respectively, with no significant difference (p = 0.386). MWA and RFA were not the independent risk factors of RBM, and patients with higher alpha-fetoprotein, non-antiviral treatment, and higher MELD score were at greater risk of RBM. Neither corresponding RFS rates (66.7%, 39.2% and 21.4% vs. 70.8%, 47% and 34.7%, p = 0.310) nor OS rates (97.3%, 88.0%, and 75.4% vs. 97.8%, 85.1%, and 70.7%, p = 0.384) for 1-, 3- and 5-years were significantly different between the MWA and RFA groups. The MWA group showed more frequent major complications (21.4% vs. 7.1%, p = 0.004) and longer hospital stays (4 days vs. 2 days, p < 0.001) compared with the RFA group. CONCLUSION: MWA showed comparable RBM, RFS, and OS rates to RFA in potentially transplantable patients with single HCC ≤ 3 cm. Compared to RFA, MWA might provide the same effect as bridge therapy.

FNDC3B protects steatosis and ferroptosis via the AMPK pathway in alcoholic fatty liver disease.

BACKGROUND: Alcoholic liver disease (ALD) is a leading cause of chronic liver disease worldwide with limited therapeutic options. The role of fibronectin type III domain-containing protein 3B (FNDC3B), an important regulator of metabolism, in ALD, and the underlying mechanism as well as its potential implication in ALD therapeutic strategies remain unknown. METHODS: Hepatocyte-specific FNDC3B knockdown or control C57BL/6 N mice received a Lieber-DeCarli diet for four weeks, followed by oral gavage (chronic-binge). Primary mouse hepatocytes and cell lines were used for in vitro studies. Liver injury, hepatic steatosis, and lipid peroxidation were assessed. RESULTS: In cultured cells and mouse livers, alcohol exposure increased FNDC3B expression. Hepatocyte-specific FNDC3B deletion aggravated alcohol-induced liver steatosis via AMP-activated protein kinase (AMPK) inhibition. In vitro, FNDC3B expression was negatively regulated by miR-192-5p. Furthermore, FNDC3B deletion significantly exacerbated ethanol-mediated lipid peroxidation. The RNA sequence assay revealed a connection between FNDC3B and ferroptosis, which was verified by the administration of the ferroptosis inhibitor ferrostatin-1 (Fer-1). Additionally, FNDC3B inhibition-mediated AMPK inactivation downregulated transferrin expression, which was associated with marked iron overload and ferroptosis. CONCLUSIONS: This study elucidated the critical role of FNDC3B in preventing hepatic steatosis and ferroptosis in response to chronic alcohol consumption. Our findings indicate that FNDC3B is a potential therapeutic target for ALD.

The Functions of Hepatitis B Virus Encoding Proteins: Viral Persistence and Liver Pathogenesis.

About 250 million people worldwide are chronically infected with Hepatitis B virus (HBV), contributing to a large burden on public health. Despite the existence of vaccines and antiviral drugs to prevent infection and suppress viral replication respectively, chronic hepatitis B (CHB) cure remains a remote treatment goal. The viral persistence caused by HBV is account for the chronic infection which increases the risk for developing liver cirrhosis and hepatocellular carcinoma (HCC). HBV virion utilizes various strategies to escape surveillance of host immune system therefore enhancing its replication, while the precise mechanisms involved remain elusive. Accumulating evidence suggests that the proteins encoded by HBV (hepatitis B surface antigen, hepatitis B core antigen, hepatitis B envelope antigen, HBx and polymerase) play an important role in viral persistence and liver pathogenesis. This review summarizes the major findings in functions of HBV encoding proteins, illustrating how these proteins affect hepatocytes and the immune system, which may open new venues for CHB therapies.

Comparison between robotic and laparoscopic inguinal hernia repair in Caucasian patients: a systematic review and meta-analysis.

BACKGROUND: Laparoscopic and robotic techniques allow surgeons to dissect and observe the groin area from the inside out, this study was to evaluate and compare the effects and safety of robotic inguinal hernia repair (R-IHR) and laparoscopic inguinal hernia repair (L-IHR) in Caucasian patients. METHODS: We searched the full texts of studies comparing R-IHR and L-IHR in multiple databases. Meta-, sensitivity, and bias analyses of the included literature were performed with Review Manager 5.2, and forest plots were drawn. The joint estimate of the risk ratio (RR) and the mean difference (MD) of the 95% confidence interval (CI) was used as a measure of the effect size. RESULTS: This meta-analysis included 8 eligible studies involving 1,379 Caucasian patients with inguinal hernia (IH). No significant difference was found in pain score (MD =1.52, 95% CI, -0.30, 3.35, P=0.10; I2=97%), length of hospital stay (MD =0.14, 95% CI, -0.03, 0.30, P for overall effect =1.63, I2=0%), or complications (RR =1.24 with 95% CI, 0.94, 1.63, P for overall effect =0.13, I2=0%) between R-IHR and L-IHR. However, there was significant difference in operative time between R-IHR and L-IHR (MD =17.17, 95% CI, 6.32, 28.03, P=0.002; I2=84%). DISCUSSION: This meta-analysis revealed only minor differences between R-IHR and L-IHR in terms of clinical effects and safety in Caucasian patients, although R-IHR has a longer operative time than L-IHR. Both R-IHR and L-IHR are suitable to treat Caucasian patients with IH.

Defect-rich honeycomb-like nickel cobalt sulfides on graphene through rapid microwave-induced synthesis for ultrahigh rate supercapacitors.

Nickel cobalt sulfides (NCS) are regarded as potential energy storage materials due to the versatile valent states and rich electrochemical activity, but their sluggish synthesis process and inferior rate performance hinder them from large-scale application. Herein, microwave-induced strategy has been employed for efficient synthesis of honeycomb-like NCS/graphene composites, which are explored as ultrahigh rate battery-type electrodes for supercapacitors. Due to the internal heat mechanism, the synthesis time of NCS by microwave could be shortened from hours to minutes. Density functional theory was simulated to uncover the interfacial effect between NCS and graphene, and the resulted Schottky barrier is in favor of enhancing redox activity and capacity. Ultimately, the obtained defect-rich nickel cobalt sulfides/graphene with thermal treatment (NCS/G-H) could exhibit a high specific capacitance of 1186 F g-1 at 1 A g-1 and sustain 89.8% capacity even after the increase of current density over 20 times, which is much superior to bare NCS and NCS/graphene. Furthermore, the assembled NCS/G-H hybrid supercapacitor delivers supreme energy density of 46.4 Wh kg-1, and retains outstanding long-term stability of 89.2% after 10 k cycles. These results indicate that the synthesized NCS/G-H by time-saving microwave-induced liquid process could be served as high rate materials for supercapacitors.

Tension-Free Mesh Repair for Incarcerated Groin Hernia: A Comparative Study.

Background. Management of emergent groin hernias remains challenging, due to limited consensus in surgical approach and repair options (eg, mesh vs nonmesh, biological mesh, and polypropylene [PP] mesh). Methods. A 5-year retrospective study was conducted on 118 patients who received emergency incarcerated groin hernia repair in Beijing Chaoyang Hospital. The incidence of surgical site infection (SSI), preoperative mortality, sepsis, and ileus was noted. In the follow-up, postoperative foreign body sensation, chronic pain, seroma/hematoma, and recurrence were recorded. The outcomes of different surgical procedures (with mesh/without mesh, biological mesh/PP mesh, transabdominal preperitoneal (TAPP)/Lichtenstein repair) were compared and analyzed. Results. Out of the 118 patients, 14 cases received suture repair (as group A); 104 cases had TAPP repair (n = 44) or Lichtenstein repair (n = 60) with meshes, including 23 cases of biological mesh (as group B); and 81 cases had repair with PP mesh (group C). There were no significant differences between the 3 groups regarding SSI, mortality, sepsis, and ileus. After 20.5 months of follow-up (range from 6 to 65 months), 21.4% of group A developed recurrence, a rate significantly higher than that of group B (4.3%) and group C (0). The incidence of seroma/hematoma in group B was higher than that in group A (7.1%) and group C (7.4%). The results between TAPP group and Lichtenstein group were comparable. Conclusion. Tension-free mesh repair in the treatment of emergency incarcerated groin hernia is safe and effective, which can reduce hernia recurrence without increasing infection risk. The results of biological mesh and PP mesh were comparable.

Decreased collagen type III synthesis in skin fibroblasts is associated with parastomal hernia following colostomy.

Parastomal hernia (PH) is a common complication following stoma formation. Abnormal collagen synthesis has been suggested to be involved in PH. The aim of the present study is to explore the effect and mechanism of the collagen synthesis on PH. Data from 157 patients with rectal cancer who received permanent colostomy were retrospectively collected and analyzed to identify the risk factors for PH. Primary culture of skin fibroblasts from patients with or without PH were performed. Cell viability, migration and invasion levels were detected by Cell Counting Kit­8, and wound healing and Transwell assays, respectively. Reverse transcription quantitative polymerase chain reaction and western blot analysis assays were performed to measure the gene and protein expression levels, respectively. The risk factors of sex, body mass index, aperture size and collagen expression were closely associated with the occurrence of PH. α1 (III) procollagen expression levels were significantly increased in patients with PH, while no marked difference in α1 (I) procollagen mRNA expression levels were observed in patients with or without PH. The viability and motility of fibroblasts from the patients with hernia were suppressed. The expression levels of matrix metalloproteinase (MMP)­2 and MMP­9 were decreased while the levels of collagen III and metalloproteinase inhibitor 1 (TIMP­1) were increased in the fibroblasts from the patients with PH. Silencing TIMP­1 expression promoted fibroblast migration and invasion and reversed the patterns of MMP­2, MMP­9 and collagen III expression in fibroblasts from the patients with PH. Decreased collagen III may inhibit the development of PH, potentially through decreases in TIMP­1 expression. Therefore, the results from the present study may provide a novel target for PH therapy.

Clinical effects of prosthetic mesh in the treatment of incarcerated groin hernias.

BACKGROUND: Incarcerated groin hernias are a common presentation as surgical emergencies. Other surgical treatment modalities are becoming more widely accepted including the use of prosthetic mesh and laparoscopy for assessment of hernia content viability and for repair. The aim of this study was to report our current experience with the use of prosthetic mesh in the treatment of incarcerated hernias and to compare the effects of different operative approaches. METHODS: This retrospective study included 219 consecutive patients who underwent herniorrhaphy for incarcerated hernia between January 2013 and December 2017 in Beijing Chao-Yang Hospital. Twenty patients who were not used mesh were excluded. Patients who died in the postoperative period due to systemic complications, as well as those who were lost during the follow-up period, were excluded from the study. Demographics, surgical details, short term and long-term outcomes were collected. Mann-Whitney U-test and χ2 test were used for statistical analysis. RESULTS: A total of 156 patients (78.4%) presented with inguinal hernias, 42 with femoral hernia (21.1%), and one with mixed hernia (0.5%), respectively. Mesh was placed in 199 patients (100%), including 15 patients with concomitant bowel resection. Four patients (2.0%) developed surgical site infections (SSI), four patients (2.0%) had foreign body sensation, one patient (0.5%) had hernia recurrence, two patients (1.0%) had chronic pain, 22 patients (11.1%) had seroma, and the mortality was 2.0%. No significant difference was noted concerning the development of surgical site infection, postoperative recurrence, chronic pain, foreign body sensation, and mortality rates between the transabdominal preperitoneal (TAPP) repair and open mesh repair. There was statistically significant difference in the postoperative incidence of seroma between two groups (12 of 49 [24.5%] vs. 10 of 150 [6.7%]; P=0.001). CONCLUSIONS: Our experience demonstrates that acutely incarcerated or strangulated groin hernia in adults is a serious neglected problem. The use of mesh could become current practice even in case of bowel resection. There was no statistically significant difference in the postoperative complications between TAPP repair and open mesh repairs except seroma.

[Anatomic study and clinical application of thinned posterior tibial artery perforator flap].

OBJECTIVE: To explore the feasibility and therapeutic effect of thinned posterior tibial artery free perforator flap for the reconstruction of soft tissue defects at dorsum of hands. METHODS: Six fresh adult lower limbs specimens were injected with red latex via arterial cannula and dissected. The number, distribution, branches, and outer diameter of posterior tibia artery perforators were observed. Based on the anatomic study, the perforator flaps were designed to reconstruct soft tissue defects at dorsum of hands and wrists. The redundant fat on the flaps was removed, but preserving the nutrient vascular system. 11 flaps were used with the size ranging from 2 cm x 5 cm to 10 cm x 14 cm. RESULTS: 43 skin perforators of posterior tibial artery were observed in six lower limbs, 29 perforators with the outer diameter is greater than 0.5 mm when they threading over the deep fascia plane, on average every 4.8 bundles of sides. The mean outside diameter of perforating artery is (1.8 +/- 0.5) mm, and the length is (44 +/- 15) mm. 6 perforators were founded both in the second and fifth zone which could be used for anastomosis for its better diameters. All flaps survived completely without any complication at donor sites. 7 cases were followed up for 3-12 months. Both satisfactory functional and cosmetic results were achieved with a soft and thinned appearance. CONCLUSIONS: The thinned posterior tibial artery free perforator flap has a reliable blood supply and good appearance. It is very suitable for the reconstruction of small or medium-sized defects at the dorsum of hands and wrists.

[A follow-up of the survival and medical factors responsible for the termination of treatment in very or extremely low birth weight infants].

OBJECTIVE: To study the outcomes of very or extremely low birth weight (VLBW/ELBW) infants born between 2000 and 2008 in a single NICU and the medical factors associated with the termination of treatment in some infants. METHODS: In this case control study, the clinical data of 148 VLBW/ELBW infants were retrospectively studied and the surviving infants were followed up. Both univariate analysis and multivariate logistic regression analysis were used to investigate the medical factors associated with terminating treatment in infants. RESULTS: Twenty infants (13.5%) failed to respond to the therapy and died in the hospital. Three infants (2.0%) died after discharge. Nineteen infants (12.8%) did not receive treatment due to decision of the guardian and died. Thirty infants (20.3%) were not followed up after discharge. Seventy-six infants (51.4%) survived, including 47 healthy infants, 2 cases of congenital diseases and 27 cases with poor prognosis. Multivariate logistic regression analysis showed there were 2 significant factors associated with terminating treatment: neonatal respiratory distress syndrome (P=0.030, OR=11.396, 95%CI 1.-102.701) and hospitalization periods (the year 2004-2006) (P=0.039, OR=9.869, 95%CI 1.118-87.140). CONCLUSIONS: The survival status of VLBW and ELBW infants needs to be improved. It is important to decrease the incidence of neonatal respiratory distress syndrome for decreasing the proportion of terminating treatment in the infants.

The risk factor of gallbladder cancer: hyperplasia of mucous epithelium caused by gallstones associates with p16/CyclinD1/CDK4 pathway.

BACKGROUNDS: The mucosa of gallbladder stimulated with gallstones and accompanied with abnormalities in bile composition, is the origin of biliary disease, which could induce metaplasia, simple hyperplasia, atypical hyperplasia and even carcinoma in situ and invasive carcinoma in gallbladder mucosa. METHODS: To determine the disorder of the balance between cell proliferation and cell cycle or apoptosis in gallbladder cancer accompanied with gallstones, removal of the gallbladder due to gallstones specimens of 88 cases were collected randomly, including a variety of 54 cases for hyperplasia, 27 cases for gallbladder cancer and 7 cases for normal gallbladder. The expressions of key cell cycle factors were detected by in situ hybridization, immunohistochemistry and Western blot. RESULTS: The expressions of CDK4 and Cyclin D1 increased along with progression of gallbladder mucosa hyperplasia; and showed highest expression in cancer group. On the contrary, p16 decreased to the lowest level in gallbladder cancer. The increased apoptotic index analyzed by TUNEL assay rose along with malignant degree to the highest level in undifferentiated carcinoma. CONCLUSIONS: Our results suggest that changes of these signals have effect on breaking the balance of proliferation and death of gallbladder epithelial cells, even on inducing gallbladder cancer.

[Factors related to the outcome of patients with chronic severe hepatitis B and effectiveness of antivirus therapy].

OBJECTIVE: To investigate the factors related to the outcome of patients with chronic severe hepatitis B and effectiveness of antivirus therapy. METHODS: The effects of the factors including age, prothrombin activity (PTA), serum HBeAg, Anti-HBe, HBV-DNA load, with or without complication, antivirus therapy and so on, on outcome of 330 patients with chronic severe hepatitis B were analyzed in this retrospective study. RESULTS: The mortality of patients with chronic severe hepatitis B was significantly higher among patients at higher age, with lower PTA, and with more complications. The mortality of patients with HBV-DNA more than 1x10(5) copies/ml (52.3 percent) was higher than that of patients whose HBV-DNA was less than 1x10(5) copies/ml (32.9 percent). There was no correlation between serum HBeAg or anti-HBe and the mortality. The mortality of patients with HBV-DNA higher than 1x10(5) copies/ml (30.38 percent) who were treated with lamivudine in 2005 was lower than that of patients whose HBV-DNA was less than 1x10(5) copies/ml (54.64 percent) who were not treated with any antiviral therapy in 2001. CONCLUSION: The higher serum virus load is the key factors of the mortality in addition to the other factors such as older age, lower PTA, more complication in the patients with chronic severe hepatitis B. The usage of antivirus therapy may be associated with lower mortality.

[Spectrophotometric determination of azithromycin by charge transfer reaction].

The charge transfer interactions of Azithromycin and 7,7,8,8-tetracyanoquinodimethane (TCNQ) or chloranilic acid (CL) were investigated by spectrophotometry. The apparent molar absorptivity of TCNQ complex is 2.7 x 10(4) L x mol(-1) x cm(-1) at 743 nm, and 5.0 x 10(4) L x mol(-1) x cm(-1) at 842 nm; and that of CL complex is 2.4 x 10(3) L x mol(-1) x cm(-1). Beers law is obeyed in the concentration range of 0-30 mg x L(-1) for TCNQ method, and 5-225 mg x L(-1) for CL method. The relative standard deviations of the two methods are 1.0% and 1.4% (n = 6), respectively. The composition of complex of Azithromycin with 7,7,8,8-tetracyanoquinodimethane or chloranilic acid is 1 : 2. This proposed method has been applied to the determination of Azithromycin in tablets with satisfactory results.

Spectroscopic study on the interaction between methylene blue and chondroitin 4-sulfate and its analytical application.

The interaction of Methylene Blue (MB) with chondroitin-4-sulfate (CHS) has been investigated using spectroscopic techniques, including UV-Vis absorption, Rayleigh resonance scattering (RRS), and circular dichroism (CD). The addition of CHS caused a decrease in the absorbance of MB at 664 nm with a new absorption band appearing at 570 nm, enhanced RRS at 314 nm and 560 nm, and also resulted in an intense CD signal at 568 nm. The Scatchard model has been applied to calculating the binding constant and the number of binding sites. The calculated parameters are consistent with the experimental results. The factors affecting the interaction were investigated. Quantitative spectroscopic methods were developed for the first time. They are based on the fact that a decrease in the absorption at 664 nm and an enhancement of the RRS intensity at 314 nm are proportional to the concentration of CHS added in a certain range. Satisfactory results were obtained on the determination of synthetic samples.

Determination of proteins with Alizarin Red S by Rayleigh light scattering technique.

A new protein determination method by enhanced Rayleigh light scattering (RLS) technique has been developed. In acid condition (pH=3.60), RLS of 1,2-dihydroxyanthraquinone-3-sulfonate (Alizarin Red S) can be greatly enhanced by addition of proteins, resulting in two characteristic peaks, 360 and 505nm, respectively. The new protein assay is based on the RLS enhancement and spectrum change. The optimum condition for the reaction was investigated. The linear range is 0.20-24.9mugml(-1) for BSA and 0.20-15.5mugml(-1) for HSA. The detection limits (S/N=3) are 9.59ngml(-1) for BSA and 9.51ngml(-1) for HSA. The results of determination for human serum samples were comparable to those obtained by Bradford method. The binding stoichiometry was determined.

3,3',5,5'-tetramethyl-N-(9-anthrylmethyl)benzidine: a dual-signaling fluorescent reagent for optical sensing of aliphatic aldehydes.

A new optical chemical sensor for continuous monitoring of aliphatic aldehydes has been proposed based on the reversible chemical reaction between a new sensing reagent, 3,3',5,5'-tetramethyl-N-(9-anthrylmethyl)benzidine (TMAB), and the analytes. TMAB, containing two receptors and two fluorescent reporters, can perform dual fluorescence responses corresponding to the reactions of hydrogen ion and carbonyl compound. When immobilized in a plasticized poly(vinyl chloride) membrane, TMAB extracts aliphatic aldehydes from aqueous solution into the bulk membrane phase and reacts with the analyte by forming a Schiff base. Since the extraction equilibrium and chemical reaction are accompanied by fluorescence increase of the sensing membrane, the chemical recognition process could be directly translated into an optical signal. At pH 3.20, the sensor exhibits a dynamic detection range from 0.017 to 4.2 mM n-butyraldehyde with a limit of detection of 0.003 mM. The forward response time (t95) of the sensor is 3-5 min, and the reverse response time is 5-7 min. The responses of the sensor toward different kinds of aldehydes and ketones depend on the lipophilicity and the reactivity of the analytes. Since the fluorescence enhancement of the sensing membrane at 296 nm/410 nm is only related to the formation of Schiff base, the measurement of aldehydes is independent of pH.

Porphyrin assembly on beta-cyclodextrin for selective sensing and detection of a zinc ion based on the dual emission fluorescence ratio.

In the present paper, a new cyclodextrin/porphyrin supramolecular sensitizer for zinc ion has been proposed based on the porphyrin dual fluorescence emission ratio. In aqueous solution, meso-tetraphenylporphyrin shows weak fluorescence, while in the presence of alkylated beta-cyclodextrin, it exhibits significant fluorescence enhancement by forming a cyclodextrin/porphyrin inclusion complex. Furthermore, the formation of a supramolecular complex causes a remarkable increase of the porphyrin metalation rate following the porphyrin fluorescence emission changes at two different emission wavelengths. The fluorescence emission of tetraphenylporphyrin at 656-nm bands decreases while that at 606 nm increases upon zinc ion interaction. Thus, the inclusion complex can behave as a ratiometric fluorescent sensor. Theoretically derivative equations for fluorescent ratiometry have been proposed for the first time. The feasibility of the proposed method is demonstrated by the performance of fluorometric detection of zinc ion. With the optimum conditions described, zinc ion in aqueous solution can be determined from 5.0 x 10(-7) to 2.5 x 10(-4) M. As the porphyrin electronic absorption and fluorescence emission are located in the visible range, and the fluorescence changes upon zinc ion interaction show high selectivity over biologically relevant cations, the inclusion complex could be used for biomedical application.

Rayleigh light scattering study on the supramolecular interactions of beta-cyclodextrin derivatives with tetrakis(4-methoxylphenyl)porphyrin.

The supramolecular interactions of beta-cyclodextrin(beta-CD) and four kinds of alkylated beta-cyclodextrin (beta-CDs), i.e. heptakis (2,6-di-O-isobutyl)-beta-cyclodextrin (Ob-beta-CD), heptakis (2,6-di-O-n-octyl)-beta-cyclodextrin (Oc-beta-CD), heptakis (2,6-di-O-n-dodecyl)-beta-cyclodextrin (Od-beta-CD) and heptakis (2,6-di-O-n-hexadecyl)-beta-cyclodextrin (Oh-beta-CD) with tetrakis(4-methoxylphenyl)porphyrin (TMOPP) have been investigated by Rayleigh light scattering (RLS) technique. Beta-CDs form 2:1 inclusion complex with TMOPP following an obvious RLS enhancement of TMOPP. The inclusion abilities of different beta-CDs were compared. The results show that the inclusion ability of beta-CDs is related to the size of the alkylated substituent. Thus, a new mechanism of inclusion interaction has been proposed. The exact stoichiometric ratios and the association constants of the inclusion complexes have been examined by application of curve fitting method.