Development and Application of Four Foodborne Pathogens by TaqMan Multiplex Real-Time PCR.

A TaqMan multiplex real-time PCR (mRT-PCR) was developed to detect simultaneously Salmonella spp., Escherichia coli O157, Staphylococcus aureus, and Listeria monocytogenes in food samples. The method involves four sets of primers and probes tailored to the unique DNA sequences found in the invA, nuc, rfbE, and hly genes of each pathogen. The generated standard curves, correlating gene copy numbers with Ct values, demonstrated high accuracy (R2 > 0.99) and efficiency (92%-104%). Meanwhile, the limit of detection was 100 CFU/mL for the four target bacteria in artificially contaminated food samples after 6-8 h of enrichment. The assay's effectiveness was further verified by testing 80 naturally contaminated food samples, showing results largely in agreement with traditional culture methods. Overall, this newly developed TaqMan mRT-PCR, inclusive of a pre-enrichment step, proves to be a dependable and effective tool for detecting single or multiple pathogens in diverse food items, offering significant potential for in vitro diagnostics.

Clinical use conditions of lead deployment and simulated lead fracture rate in left bundle branch area pacing.

INTRODUCTION: Left bundle branch area pacing (LBBAP) is achieved by advancing the lead tip deep in the septum. Most LBBAP implants are performed using the Medtronic SelectSecure™ MRI SecureScan™ Model 3830 featuring a unique 4 Fr fixed helix lumenless design. Details of lead use conditions and long-term reliability have not been reported. This study was designed to quantify the mechanical use conditions for the 3830 lead during and after LBBAP implant, and to evaluate reliability using bench testing and simulation. METHODS: Fifty bradycardia patients with implantation of the 3830 lead for LBBAP were enrolled. Use conditions of lead deployment at implantation were collected and computed tomography (CT) scans were performed at 3-month follow-up. Curvature amplitude along the pacing lead was determined with CT images. Fatigue bending was performed using accelerated testing in a more severe environment than routine clinical use conditions. Conductor fracture rate in a simulated patient population was estimated based on clinical use conditions and fatigue test results. RESULTS: The number of attempts to place the 3830 lead for LBBAP was 2.1 ± 1.3 (range: 1-7) with 13 ± 6 lead rotations at the final attempt. Extreme implant conditions were simulated in bench testing with 5 applications of 20 turns followed by up to 400 million bending cycles. Reliability modeling predicted a 10-year fracture rate of 0.02%. CONCLUSIONS: LBBAP implants require more lead rotations than standard pacing implants and result in unique lead bending. Application of simulated LBBAP use conditions to the 3830 lead in an accelerated in-vitro model does not produce excess conductor fractures. IMAGE-LBBP Study ID of ClinicalTrial.GOV: NCT04119323.

Differentiating left bundle branch pacing and left ventricular septal pacing: An algorithm based on intracardiac electrophysiology.

BACKGROUND: Left bundle branch pacing (LBBP) is a new near-physiological pacing modality. Distinguishing left ventricular septal only pacing (LVSP) from nonselective LBBP still needs clarification. This prospective study sought to establish a differentiation algorithm to confirm LBBP. METHODS AND RESULTS: LBBP was attempted in consecutive patients. If direct LBB capture (LBBP) could not be confirmed, LVSP was considered to have been achieved. Intracardiac left ventricular (LV) activation sequence and activation time were analyzed using coronary sinus (CS) electrogram mapping. Electrophysiological parameters including S-CSmax, S-CSmin, LV lateral wall activation time, ΔLV, and LBB potential were compared between LBBP and LVSP. Stimulated LV activation time (S-LVAT) and stimulated QRS duration (S-QRSd) were also compared between the two groups. Multivariate logistic regression analysis was used to develop a prediction algorithm for LBBP. Of the 43 prospectively enrolled patients, 27 underwent LBBP and 16 underwent LVSP. All LBBP patients showed identical LV activation sequences to their intrinsic rhythm while no LVSP patients maintained their intrinsic sequence. S-CSmax, ΔLV, LV lateral wall activation time, and S-LVAT during LBBP were significantly shorter than those during LVSP. Combining LBB potential with S-LVAT had the largest area under the curve (AUC) of 0.985 for confirming LBBP with a sensitivity of 95.2% and a specificity of 93.7%. CONCLUSIONS: Compared with LVSP, LBBP preserves a normal LV activation sequence and better electrical synchrony. A combination of LBB potential with S-LVAT can be an effective and practical model to distinguish LBBP from LVSP during implantation in patients with normal LBB activation.

Computed tomography imaging-identified location and electrocardiographic characteristics of left bundle branch area pacing in bradycardia patients.

INTRODUCTION: Left bundle branch area pacing (LBBAP) is a novel physiological pacing modality. The relationship between the pacing lead tip location and paced electrocardiographic (ECG) characteristics remains unclear. The objectives are to determine the lead tip location within the interventricular septum (IVS) and assess the location-based ECG QRS duration (QRSd) and left ventricular activation time (LVAT). METHODS: This multicenter study enrolled 50 consecutive bradycardia patients who met pacemaker therapy guidelines and received LBBAP implantation via the trans-ventricular septal approach. After at least 3 months postimplant, 12-lead ECGs and pacing parameters were obtained. Cardiac computed tomography (CT) imaging was performed to assess the LBBAP lead tip distance from the LV blood pool. RESULTS: Among the 50 patients, analyzable CT images were obtained in 42. In 23 of the 42 patients, the lead tips were within 2 mm to the LV blood pool (the LV subendocardial (LVSE) group), 13 between 2 and 4 mm (the Near-LVSE group), and the remaining 6 beyond 4 mm (the Mid-LV septal (Mid-LVS) group). No significant differences in paced QRSd were found among the three groups (LVSE, 107 ± 15 ms; Near-LVSE, 106 ± 13 ms; Mid-LVS, 104 ± 15 ms; p = .87). LVAT in the LVSE (64 ± 7 ms) was significantly shorter than in the Mid-LVS (72 ± 8 ms; p < .05), but not significantly different from that in the Near-LVSE (69 ± 8 ms; p > .05). CONCLUSION: In routine LBBAP practice, paced narrow QRSd and fast LVAT, indicative of physiological pacing, were consistently achieved for lead tip location in the LV subendocardial or near LV subendocardial region.

Five major two components systems of Staphylococcus aureus for adaptation in diverse hostile environment.

Staphylococcus aureus is an eminent and opportunistic human pathogen that can colonize in the intestines, skin tissue and perineal regions of the host and cause severe infectious diseases. The presence of complex regulatory network and existence of virulent gene expression along with tuning metabolism enables the S. aureus to adopt the diversity of environments. Two component system (TCS) is a widely distributed mechanism in S. aureus that permit it for changing gene expression profile in response of environment stimuli. TCS usually consist of transmembrane histidine kinase (HK) and cytosolic response regulator. S. aureus contains totally 16 conserved pairs of two component systems, involving in different signaling mechanisms. There is a connection among these regulatory circuits and they can easily have effect on each other's expression. This review has discussed five major types of TCS in S. aureus and covers the recent knowledge of their virulence gene expression. We can get more understanding towards staphylococcal pathogenicity by getting insights about gene regulatory pathways via TCS, which can further provide implications in vaccine formation and new ways for drug design to combat serious infections caused by S. aureus in humans.

A pilot study to determine if left ventricular activation time is a useful parameter for left bundle branch capture: Validated by ventricular mechanical synchrony with SPECT imaging.

BACKGROUND: Left bundle branch (LBB) pacing has emerged as a novel pacing modality. Left ventricular activation time (LVAT) was reported to be associated with the activation via LBB, but the value of LVAT for determining LBB pacing was unknown. We conducted a pilot study to determine if LVAT could define LBB capture by validating left ventricular (LV) mechanical synchrony. METHODS: We analyzed LVAT in 68 bradycardia-indicated patients who received LBB pacing. LVAT was measured from the stimulus to R-wave peak in lead V5 and V6. LV mechanical synchrony assessed by SPECT MPI was compared according to the value of LVAT and the presence of LBB potential. RESULTS: The mean LVAT was 75.4 ± 12.7 ms. LBB potential was recorded in 47 patients (69.1%). Patients with LVAT < 76 ms had better LV mechanical synchrony than those with LVAT ≥ 76 ms. Patients with LVAT < 76 ms or LBB potential had better mechanical synchrony than those with LVAT ≥ 76 ms and no potential. LVAT < 76 ms could predict the normal synchrony with a sensitivity of 88.9% and a specificity of 87.5%. CONCLUSION: A short LVAT indicated favorable mechanical synchrony in SPECT imaging. LVAT < 76 ms might be a practical parameter for defining LBB capture.

Efficacy of upgrading to left bundle branch pacing in patients with heart failure after right ventricular pacing.

BACKGROUND: Chronic right ventricular (RV) pacing is associated with an increased incidence of heart failure and mortality. Left bundle branch (LBB) pacing could produce near-physiological electrical activation and mechanical synchrony. We aimed to report the effects of upgrading to LBB pacing in heart failure patients after chronic RV pacing. METHODS: The indications included pacing-induced cardiomyopathy (PICM) in Group 1 and heart failure after RV pacing with left ventricular ejection fraction (LVEF) ≥ 50% in Group 2. LBB pacing was achieved by penetrating the pacing lead to the subendocardium of left-sided interventricular septum through the venous access. Left ventricular activation time (LVAT) was measured from the pacing stimulus to the ascending peak of lead V5 or V6. All patients underwent clinical and echocardiographic evaluations before and after upgrading. RESULTS: Totally 27 patients (13 in Group 1 and 14 in Group 2) were consecutively enrolled. The mean follow-up time after upgrade was 10.4 ± 6.1 months. Paced QRS duration was significantly shortened from 174.1 ± 15.8 milliseconds to 116.6 ± 11.7 milliseconds (p < .0001). The mean LVAT was 83.2 ± 11.7 milliseconds. LVEF increased from 40.3 ± 5.2% before upgrading to 48.1 ± 9.5% at follow-up in patients with PICM. Serum N-terminal probrain natriuretic peptide levels decreased and New York Heart Association classification improved in both groups. No upgrade-related complications were observed. CONCLUSIONS: Upgrading to LBB pacing was feasible and effective with improved cardiac function in heart failure patients with both reduced and preserved LVEF after RV pacing.

The efficacy of left bundle branch area pacing compared with biventricular pacing in patients with heart failure: A matched case-control study.

BACKGROUND: Left bundle branch area pacing (LBBAP) was reported to improve cardiac function by correcting complete left bundle branch block (CLBBB). Our study aimed to compare the efficacy of LBBAP and biventricular pacing (BIVP) in heart failure patients with CLBBB. METHODS: Ten patients prospectively underwent LBBAP (LBB-CRT group) and 30 patients received BIVP (BIV-CRT group) were matched using propensity score matching. LBBAP was achieved by the trans-interventricular septum method. Echocardiography, electrocardiogram, NYHA classification, and blood B-type natriuretic peptide concentration were evaluated at preimplantation and at 6-month follow up. CRT response was defined as at least 15% decrease in left ventricular end-systolic volume. RESULTS: In the LBB-CRT group, CLBBB were successfully corrected by LBBAP with no complications. QRS duration (QRSd) significantly decreased after implantation in both groups, and the decrease of QRSd in the LBB-CRT group was significantly greater than that in the BIV-CRT group (60.80 ± 20.09 vs. 33.00 ± 21.48 ms, p = .0009). The echocardiographic measurements including left ventricular end-diastolic diameter, left ventricular end-systolic diameter, and left ventricular ejection fraction significantly improved after 6 months in both groups. The response rate was significantly higher in LBB-CRT group than BIV-CRT group (100.00% vs. 63.33%, p = .038). The percentage of patients in New York Heart Association classification Grades I and II was significantly higher in the LBB-CRT group compared with that in the BIV-CRT group (median 1.5 vs. 2.0, p = .029) at 6-month follow-up. CONCLUSIONS: It is effective and safe to correct CLBBB with LBBAP in heart failure patients. Compared with BIVP, LBBAP can better optimize electrical synchrony and improve cardiac function.

Lead performance and clinical outcomes of patients with permanent His-Purkinje system pacing: a single-centre experience.

AIMS: His-Purkinje system (HPS) pacing, including His bundle (HB) and left bundle branch (LBB) pacing, has emerged as a highlighted topic in recent years. Comparisons in lead performance and clinical outcomes between HB and LBB pacing were seldom reported. We aimed to investigate the mid-long-term lead performance and clinical outcomes of permanent HPS pacing patients in our centre. METHODS AND RESULTS: Permanent HB pacing was implemented by placing the pacing lead helix at the HB area. Left bundle branch pacing was achieved by placing the lead helix in the left-side sub-endocardium of the interventricular septum. Pacing parameters, 12-lead ECG, echocardiography, and clinical outcomes were evaluated during follow-up. A total of 64 patients with HB pacing and 185 with LBB pacing were included. Left bundle branch pacing exhibited a slightly longer paced QRS duration than HB pacing (117.7 ± 11.0 vs. 113.7 ± 19.8 ms, P = 0.04). Immediate post-operation, LBB pacing had a significant higher R-wave amplitude (16.5 ± 7.5 vs. 4.3 ± 3.6 mV, P < 0.001) and lower capture threshold (0.5 ± 0.1 vs. 1.2 ± 0.8 V, P < 0.001) compared with HB pacing. During follow-up, an increase in capture threshold of >1.0 V from baseline was found in eight (12.5%) patients in the HB pacing group and none in LBB pacing. Paced QRS morphology changed from Qr to QS in lead V1 in seven patients (3.8%) with LBB pacing. Both HB and LBB pacing preserved cardiac function in patients with left ventricular ejection fraction (LVEF) over 50%. In patients with LVEF <50%, both HB and LBB pacing improved clinical outcomes during follow-up. CONCLUSION: His-Purkinje system pacing produced favourable electrical synchrony and improved cardiac function in patients with heart failure. Left bundle branch pacing showed superior pacing parameters over HB pacing. Lead micro-displacement with changes in paced QRS morphology posts a concern in LBB pacing.

Feasibility and cardiac synchrony of permanent left bundle branch pacing through the interventricular septum.

AIMS: Left bundle branch pacing (LBBP) recently emerges as a novel pacing modality. We aimed to evaluate the feasibility and cardiac synchrony of permanent LBBP in bradycardia patients. METHODS AND RESULTS: Left bundle branch pacing was successfully performed in 56 pacemaker-indicated patients with normal cardiac function. Left bundle branch pacing was achieved by penetrating the interventricular septum (IVS) into the left side sub-endocardium with the pacing lead. His-bundle pacing (HBP) was successfully performed in another 29 patients, 19 of whom had right ventricular septal pacing (RVSP) for backup pacing. The QRS duration, left ventricular (LV) activation time (LVAT), and mechanical synchrony using phase analysis of gated SPECT myocardial perfusion imaging were evaluated. Paced QRS duration in LBBP group was significantly shorter than that in RVSP group (117.8 ± 11.0 ms vs. 158.1 ± 11.1 ms, P < 0.0001) and wider than that in HBP group (99.7 ± 15.6 ms, P < 0.0001). Left bundle branch potential was recorded during procedure in 37 patients (67.3%). Left bundle branch pacing patients with potential had shorter LVAT than those without potential (73.1 ± 11.3 ms vs. 83.2 ± 16.8 ms, P = 0.03). Left bundle branch pacing patients with potential had similar LV mechanical synchrony to those in HBP group. R-wave amplitude and capture threshold of LBBP were 17.0 ± 6.7 mV and 0.5 ± 0.1 V, respectively at implant and remained stable during a mean follow-up of 4.5 months without lead-related complications. CONCLUSION: Permanent LBBP through IVS is safe and feasible in bradycardia patients. Left bundle branch pacing could achieve favourable cardiac electrical and LV mechanical synchrony.

Permanent His bundle pacing in heart failure patients: A systematic review and meta-analysis.

BACKGROUND: Cardiac resynchronization therapy (CRT) is the standard-of-care therapy for the patients with heart failure and left ventricular (LV) dyssynchrony. However, approximately 30% of the patients show no response. Recent studies have shown that His bundle pacing (HBP) could be an alternative for the patients with CRT indications. The purpose of this study was to evaluate the efficacy of HBP in patients with heart failure. METHODS: We searched PubMed and Embase databases for studies evaluating HBP in patients with heart failure and LV dyssynchrony. The successful rate of implantation, QRS duration, pacing threshold, LV function at baseline and follow-up, and mortality rates were extracted and summarized. RESULTS: Eleven studies including 494 patients were included in this analysis. The overall successful rate for implantation was 82.4%. The main indications for HBP were CRT candidates and cardiomyopathy with atrial fibrillation undergoing atrioventricular node ablation. Permanent HBP resulted in narrow QRS duration of 116.3 ± 13.9 ms after implantation. LV functions, including echocardiographic parameters and clinical outcomes, significantly improved at follow-up (P < 0.001). However, there was a trend of increased capture and bundle branch block correction thresholds at follow-up compared to baseline (P = 0.01 and 0.02, respectively). During a mean follow-up of 23.7 months, 5.9% of the patients experienced heart failure-related hospitalization and the mortality rate was 9.1%. CONCLUSION: Permanent HBP has shown promising results for heart failure patients in small observational studies. Randomized controlled trials are needed to assess the efficacy of HBP in these patients.

Assessment of left ventricular contraction patterns using gated SPECT MPI to predict cardiac resynchronization therapy response.

BACKGROUND: The U-shaped left ventricular (LV) contraction pattern, identified by MRI or echocardiography, is associated with improved CRT response. Gated SPECT MPI can measure both myocardial viability and mechanical dyssynchrony in a single scan. The aim of this study is to examine the relationship of the LV contraction pattern and the response of CRT in patients with left bundle branch block (LBBB). METHODS: Fifty-eight patients who met CRT guidelines and who had pre-CRT MPI were enrolled. Myocardial segments with tracer uptake < 50% of maximum were considered as scar. The LV contraction pattern was considered as U-shaped or non-U-shaped (U-shaped has a block line in the direction of contraction propagation). CRT response was defined as an increase in left ventricular ejection fraction ≥ 5% after 6-month follow-up. RESULTS: Twenty-eight patients (48%) had a U-shaped contraction pattern and thirty patients (52%) had a non-U-shaped contraction pattern. The U-shaped group showed a significantly higher response rate than the non-U-shaped group (90% vs. 57%; P = 0.005). By univariate and multivariate logistic regression analysis, the U-shaped pattern was an independent predictor of CRT response. CONCLUSION: Non-invasive gated SPECT MPI can characterize LV mechanical contraction patterns. A U-shaped contraction pattern identified is associated with improved CRT response. This may prove useful for improved patient selection for CRT.

The incidence and outcomes of delayed response to cardiac resynchronization therapy.

BACKGROUND: The incidence and clinical outcomes of delayed response to cardiac resynchronization therapy (CRT) have not been well clarified. We aimed to observe the incidence and prognosis of delayed response and to identify its possible mechanisms. METHODS: A total of 115 CRT patients were retrospectively analyzed in our study. Patients who met the enrollment criteria were divided into two groups: group A, conventional responders who showed response at 1-year follow-up, and group B, delayed responders who showed response after 1-year follow-up. CRT response was defined as an absolute increase of ≥10% in left ventricular ejection fraction. RESULTS: Fifty-two patients (61 ± 12 years, 37 male) experienced conventional response to CRT and 17 patients (63 ± 11 years, 10 male) experienced delayed response. The mean follow-up time was 5.2 ± 2.4 years. The incidence of delayed response was 14.8% (17/115). All-cause mortality and hospitalization rates for heart failure were similar for delayed and conventional responders. Multivariate logistic regression analysis revealed that scar burden > 35% was an independent predictor of CRT delayed response (odds ratio 8.794, P  =  0.038). CONCLUSIONS: A significant proportion of patients demonstrated delayed response to CRT. The delayed responders had a good prognosis that was similar to that of conventional responders. More scar burden might be related to the incidence of delayed response.

Hyaluronic acid conjugation facilitates clearance of intracellular bacterial infections by streptomycin with neglectable nephrotoxicity.

Antibiotics such as ß-lactams and aminoglycosides are often subtherapeutic to intracellular infections due to their high hydrophilicity, resulting in low effectiveness against intracellular pathogens and the emergence of antibiotic resistance. Here we reported that an endogenous aminoglycan, hyaluronic acid could be an effective carbohydrate carrier of the aminoglycoside antibiotic, streptomycin against intracellular pathogens. This conjugation could enhance phagocytic activity, and facilitated the entry of streptomycin into host cells via a CD44-mediated pathway. It appeared that this conjugate could clear intracellular bacteria in phagocytic or nonphagocytic cells in a short-term therapy (4 h) at a lower effective dose. In addition, this conjugate was more efficient in reducing bacteria burden in an in vivo acute infection model than streptomycin did. Interestingly, subcutaneous injection of this conjugate at an excess amount had undetectable side effects such as nephrotoxicity. These results suggested that hyaluronic acid might be an efficient Trojan horse for the delivery of hydrophilic antibiotics to deal with intracellular infections.

A repA-based ELISA for discriminating cattle vaccinated with Brucella suis 2 from those naturally infected with Brucella abortus and Brucella melitensis.

The commonest ways of diagnosing brucellosis in animals include the Rose-Bengal plate agglutination test, the buffered plate agglutination test (BPA), the slide agglutination test, the complement fixation test, and the indirect enzyme linked immunosorbent assay (I-ELISA). However, these methods cannot discriminate the Brucella vaccine strain (Brucella suis strain 2; B. suis S2) from naturally acquired virulent strains. Of the six common Brucella species, Brucella melitensis, Brucella abortus, and B. suis are the commonest species occurring in China. To develop an ELISA assay that can differentiate between cows inoculated with B. suis S2 and naturally infected with B. abortus and B. melitensis, genomic sequences from six Brucella spp. (B. melitensis, B. abortus, B. suis, Brucella canis, Brucella neotomae and Brucella ovis) were compared using Basic Local Alignment Search Tool software. One particular gene, the repA-related gene, was found to be a marker that can differentiate B. suis from B. abortus and B. melitensis. The repA-related gene of B. suis was PCR amplified and subcloned into the pET-32a vector. Expressed repA-related protein was purified and used as an antigen. The repA-based ELISA was optimized and used as specific tests. In the present study, serum from animals inoculated with the B. suis S2 vaccine strain had positive repA-based ELISA results. In contrast, the test-positive reference sera against B. abortus and B. melitensis had negative repA-based ELISA results. The concordance rate between B. abortus antibody-negative (based on the repA-based ELISA) and the Brucella gene-positive (based on the 'Bruce ladder' multiplex PCR) was 100%. Therefore, the findings suggest that the repA-based ELISA is a useful tool for differentiating cows vaccinated with the B. suis S2 and naturally infected with B. abortus and B. melitensis.

Polysaccharides play an anti-fibrotic role by regulating intestinal flora: A review of research progress.

Fibrosis is a common pathological process affecting multiple organs. It refers to an increase in fibrous connective tissue and a decrease in parenchymal cells in damaged tissues or organs. This may lead to structural damage and functional decline or even organ failure. The incidence of fibrosis is increasing worldwide, and the need for safe and effective therapeutic drugs and treatments is pivotal. The intestinal tract has a complex network of exchanging information with various tissues in the body. It contains a sizeable microbial community of which the homeostasis and metabolites are closely related to fibrosis. Polysaccharides are a class of biomolecules present in natural products; they have potential value as anti-fibrotic prebiotics. Recently, polysaccharides have been found to improve fibrosis in different organs by decreasing inflammation and modulating the immune function and intestinal microbiota. In this paper, we reviewed the progress made in research concerning polysaccharides and organ fibrosis in relation to the intestinal microbiota from the pathogenesis of fibrosis to the relationship between the intestinal flora and fibrosis. Furthermore, we provide ideas and references for future polysaccharide-drug discovery and strategies for the treatment of fibrosis.

Polysaccharides from fructus corni: Extraction, purification, structural features, and biological activities.

Fructus Corni, derived from the dried fruit of Cornus officinalis Sieb. Et Zucc., is widely used as a food source and Chinese herb. Fructus Corni, as an indispensable ingredient in Liuwei Dihuang decoction, tonifies the liver and kidneys. As the main component of water decoctions, Fructus Corni polysaccharides demonstrate multifaceted effects, including hypoglycemic, hypolipidemic, antioxidant, anti-aging, sexual function regulation, and anti-epileptic, The ultrasound-assisted extraction method obtained the highest yields of Fructus Corni polysaccharides. However, it has notable shortcomings and lacks further innovation. The homogeneous polysaccharides obtained from Fructus Corni are mostly neutral polysaccharides with relatively limited structure, and the mechanism of their biological activity needs to be further elucidated. In addition, different extraction, isolation and purification methods may change the molecular weight, monosaccharide composition, and biological activity of polysaccharides. Therefore, this study systematically summarized the extraction, purification, structural features, and biological activities of Fructus Corni polysaccharides. This study aimed to provide support for the ongoing development and application of Fructus Corni polysaccharides.

The application of pH-responsive hyaluronic acid-based essential oils hydrogels with enhanced anti-biofilm and wound healing.

pH could play vital role in the wound healing process due to the bacterial metabolites, which is one essential aspect of desirable wound dressings lies in being pH-responsive. This work has prepared a degradable hyaluronic acid hydrogel dressing with wound pH response-ability. The aldehyde-modified hyaluronic acid (AHA) was obtained, followed by complex mixture formation of eugenol and oregano antibacterial essential oil in the AHA-CMCS hydrogel through the Schiff base reaction with carboxymethyl chitosan (CMCS). This hydrogel composite presents pH-responsiveness, its disintegration mass in acidic environment (pH = 5.5) is 4 times that of neutral (pH = 7.2), in which the eugenol release rate increases from 37.6 % to 82.1 %. In vitro antibacterial and in vivo wound healing investigations verified that hydrogels loaded with essential oils have additional 5 times biofilm removal efficiency, and significantly accelerate wound healing. Given its excellent anti-biofilm and target-release properties, the broad application of this hydrogel in bacteria-associated wound management is anticipated.

Clearance of intracellular bacterial infections by hyaluronic acid-based ROS responsive drug delivery micelles.

Pathogenic bacteria residing inside cells could cause disruption of cellular metabolic balance. Therefore, basing on high oxidative stress response of the intracellular bacteria infected micro-environment, a novel amphipathic micelle (HATAD-TCS) was developed consisting of hyaluronic acid-derivative and reactive oxygen species (ROS) - responsive group and antibacterial agent triclosan (TCS). ROS-generating cinnamaldehyde (CA) was incorporated into ROS-cleavable linkages which are future linked to the 1-decylamine to form hydrophobicity. The cinnamaldehyde released did not just killed bacteria however, also maintained intracellular ROS levels. In this study, the HATAD-TCS micelles have been characterized by scanning electron microscopy (SEM) and dynamic light scattering (DLS). The HATAD-TCS micelles could release drug gradually upon exposure to endogenous ROS being caused by infected intracellular bacteria. Furthermore, the more promising therapeutic effect of the HATAD-TCS micelles was observed in a mouse pneumonia model. These results might highlight a ROS-responsive hyaluronic acid-based nanoparticle, which could effectively treat intracellular bacterial infections.

Anti-inflammatory Effect of a Novel Pectin Polysaccharide From Rubus chingii Hu on Colitis Mice.

Rubus chingii Hu has been used as a functional food for a long time. A novel pectin polysaccharide named RCHP-S from R. chingii Hu was structurally identified and explored its anti-inflammatory effect on colitis mice. RCHP-S was composed of mannose, rhamnose, glucuronic acid, galacturonic acid, glucose, galactose, and arabinose. NMR spectroscopy and methylation analysis showed that RCHP-S was mainly composed of HG-type pectin domains but also contains a small amount of RG-I. The anti-inflammatory tests indicated that the mouse macrophage RAW 264.7 cells pretreated with RCHP-S could show a significant inhibitory effect on the mRNA level of iNOS, IL-1ß, IL-6, and TNF-α in vitro. Polysaccharide RCHP-S reduced the enteritis symptoms in dextran sulfate sodium (DSS)-induced colitis mice by inhibiting released inflammatory factors. These results indicated that the R. chingii Hu polysaccharide can be used as food additives for the treatment of intestinal inflammation.