A Review of High-Temperature Aerogels: Composition, Mechanisms, and Properties.

High-temperature aerogels have garnered significant attention as promising insulation materials in various industries such as aerospace, automotive manufacturing, and beyond, owing to their remarkable thermal insulation properties coupled with low density. With advancements in manufacturing techniques, the thermal resilience of aerogels has considerable improvements. Notably, polyimide-based aerogels can endure temperatures up to 1000 °C, zirconia-based aerogels up to 1300 °C, silica-based aerogels up to 1500 °C, alumina-based aerogels up to 1800 °C, and carbon-based aerogels can withstand up to 2500 °C. This paper systematically discusses recent advancements in the thermal insulation performance of these five materials. It elaborates on the temperature resistance of aerogels and elucidates their thermal insulation mechanisms. Furthermore, it examines the impact of doping elements on the thermal conductivity of aerogels and consolidates various preparation methods aimed at producing aerogels capable of withstanding temperatures. In conclusion, by employing judicious composition design strategies, it is anticipated that the maximum tolerance temperature of aerogels can surpass 2500 °C, thus opening up new avenues for their application in extreme thermal environments.

Mechanisms on the removal of gram-negative/positive antibiotic resistant bacteria and inhibition of horizontal gene transfer by ferrate coupled with peroxydisulfate or peroxymonosulfate.

The existence of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) has been a global public environment and health issue. Due to the different cell structures, gram-positive/negative ARB exhibit various inactivation mechanisms in water disinfection. In this study, a gram-negative ARB Escherichia coli DH5α (E. coli DH5α) was used as a horizontal gene transfer (HGT) donor, while a gram-positive ARB Bacillus as a recipient. To develop an efficient and engineering applicable method in water disinfection, ARB and ARGs removal efficiency of Fe(VI) coupled peroxydisulfate (PDS) or peroxymonosulfate (PMS) was compared, wherein hydroxylamine (HA) was added as a reducing agent. The results indicated that Fe(VI)/PMS/HA showed higher disinfection efficiency than Fe(VI)/PDS/HA. When the concentration of each Fe(VI), PMS, HA was 0.48 mM, 5.15 log E. coli DH5α and 3.57 log Bacillus lost cultivability, while the proportion of recovered cells was 0.0017 % and 0.0566 %, respectively, and HGT was blocked. Intracellular tetA was reduced by 2.49 log. Fe(IV) and/or Fe(V) were proved to be the decisive reactive species. Due to the superiority of low cost as well as high efficiency and practicality, Fe(VI)/PMS/HA has significant application potential in ARB, ARGs removal and HGT inhibition, offering a new insight for wastewater treatment.

The combination of ciprofloxacin and dialkyldimethyl ammonium compound synergistically proliferated intracellular resistance genes in nitrifying system.

Antibiotics and quaternary ammonium compounds (QACs) usually co-exist in wastewater treatment plants. Hence, three sequencing batch reactors were established and named as R1, R2 and R3, to investigate the effects of individual and combined exposure of different concentrations of ciprofloxacin (CIP) (0.2, 1.0 and 2.0 mg/L) and dialkyldimethyl ammonium compound (DADMAC) (0.4, 2.0 and 4.0 mg/L) on the performance, microbial community structures and resistance genes (RGs) in nitrifying system during 150 days. Results showed that CIP had a slight effect on ammonia oxidation activity, while 2.0 and 4.0 mg/L DADAMAC could obviously inhibit it, and the combination of CIP and DADMAC had a synergistic inhibitory effect. Besides, both CIP and DADMAC caused partial nitrification, and the order of nitrite accumulation rate was ranked as R3 > R2 > R1. The combination of CIP and DADMAC had an antagonistic effect on the increase of sludge particle size and α-Helix/(ß-Sheet + Random coil) was lowest in R3 (0.40). The combination of CIP and DADMAC synergistically stimulated most intracellular RGs in sludge, and the relative abundances of target RGs (e.g., qacEdelta1-01, qacH-01 and qnrS) at the end of operation in R3 were increased by 4.61-18.19 folds compared with those in CK, which were 1.34-5.57 folds higher than the R1 and R2. Moreover, the combination of CIP and DADMAC also promoted the transfer of RGs from sludge to water and enriched more potential hosts of RGs, further promoting the spread of RGs in nitrifying system. Thus, the combined pollution of CIP and DADMAC in wastewaters should attract more attentions.

Microbial community of municipal drinking water in Hangzhou using metagenomic sequencing.

While traditional culture-dependent methods can effectively detect certain microorganisms, the comprehensive composition of the municipal drinking water (DW) microbiome, including bacteria, archaea, and viruses, remains unknown. Metagenomic sequencing has opened the door to accurately determine and analyze the entire microbial community of DW, providing a comprehensive understanding of DW species diversity, especially in the context of public health concerns during the COVID-19 era. In this study, we found that most of the culturable bacteria and some fecal indicator bacteria, such as Escherichia coli and Pseudomonas aeruginosa, were non-culturable using culture-dependent methods in all samples. However, metagenomic analysis showed that the predominant bacterial species in the DW samples belonged to the phyla Proteobacteria and Planctomycetes. Notably, the genus Methylobacterium was the most abundant in all water samples, followed by Sphingomonas, Gemmata, and Azospirilum. While low levels of virulence-associated factors, such as the Esx-5 type VII secretion system (T7SS) and DevR/S, were detected, only the erythromycin resistance gene erm(X), an rRNA methyltransferase, was identified at low abundance in one sample. Hosts corresponding to virulence and resistance genes were identified in some samples, including Mycobacterium spp. Archaeal DNA (Euryarchaeota, Crenarchaeota) was found in trace amounts in some DW samples. Viruses such as rotavirus, coxsackievirus, human enterovirus, and SARS-CoV-2 were negative in all DW samples using colloidal gold and real-time reverse transcription polymerase chain reaction (RT‒PCR) methods. However, DNA encoding a new order of reverse-transcribing viruses (Ortervirales) and Herpesvirales was found in some DW samples. The metabolic pathways of the entire microbial community involve cell‒cell communication and signal secretion, contributing to cooperation between different microbial populations in the water. This study provides insight into the microbial community and metabolic process of DW in Hangzhou, China, utilizing both culture-dependent methods and metagenomic sequencing combined with bioinformatics tools during the COVID-19 pandemic era.

The Feasibility of an Educational Cartoon Video for Improving Adherence with Amblyopia Treatment in Children.

Background: Previous studies have shown that it is necessary to evaluate adherence during the treatment process, using educational intervention methods which have been shown to improve adherence with patching treatment. A previous study reported that an educational cartoon had significantly improved adherence with patching. However, this black-white cartoon is not commercially available. Objective: This study investigates the feasibility of a 4-minute educational cartoon video in improving adherence with patching therapy for amblyopic children. Methods: Children (3 to 10 years old) with unilateral amblyopia who were prescribed 2 hours or 6 hours of patching per day were enrolled. Objective adherence to the treatment was tracked using a microsensor. Children returned after 4 weeks ± 2 days to measure adherence. Participants with adherence ≤50% were eligible to watch the educational cartoon video. They continued with the previously prescribed treatment (2 hours or 6 hours patching) for an additional week to evaluate the follow-up adherence. Results: A total of 27 participants were enrolled. The mean age (SD) was 6.6 (1.5) years. Twenty-two participants (12 in the 2 hours patching group and 10 in the 6 hours patching group) had adherence ≤50% and watched our cartoon video. The cartoon video improved mean adherence (SD) from 29.6% (11.9%) to 56.8% (12.1%) in all 22 participants from both regimens (paired 2-tailed t-test, t= -11, P < 0.000). Conclusion: The Educational cartoon video is feasible for use in a clinical setting. These data showed a trend of improvement in adherence with both patching regimens in children after watching the educational cartoon video.

miR-1290 promotes IL-8-mediated vascular endothelial cell adhesion by targeting GSK-3ß.

BACKGROUND: MicroRNA-1290 (miR-1290) has been reported to be involved in many diseases and play a key role during the development process. However, the role of miR-1290 in atherosclerosis (AS) is still unclear. METHODS AND RESULTS: The current study showed that the expressions of miR-1290 were high in serum of patients with hyperlipidemia. The functional role of miR-1290 were then investigated in human umbilical vein endothelial cells (HUVECs). Here, we found that miR-1290 expressions were notably enhanced in HUVECs mediated by IL-8. miR-1290 inhibitor repressed monocytic THP-1 cells adhesion to HUVECs by regulating ICAM-1 and VCAM-1, inhibited proliferation through regulating cyclinD1 and PCNA, and inhibited inflammatory response by regulating IL-1ß. Mechanistically, we verified that miR-1290 mimic was able to directly target the 3'-UTR of GSK-3ß mRNA using luciferase reporter assay. Knockdown of GSK-3ß (si-GSK-3ß) promoted HUVECs adhesion and the expression of IL-1ß, and partially restore the depression effect of miR-1290 inhibitor on HUVECs adhesion and inflammation. In contrast, si-GSK-3ß inhibited the proliferation of HUVECs and the expression of cyclinD1 and PCNA. CONCLUSIONS: In summary, our study revealed that miR-1290 promotes IL-8-mediated the adhesion of HUVECs by targeting GSK-3ß. However, GSK-3ß is not the target protein for miR-1290 to regulate the proliferation of HUVECs. Our findings may provide potential target in atherosclerosis treatment.

Dissection of Genetic Basis Underpinning Kernel Weight-Related Traits in Common Wheat.

Genetic dissection kernel weight-related traits is of great significance for improving wheat yield potential. As one of the three major yield components of wheat, thousand kernel weight (TKW) was mainly affected by grain length (GL) and grain width (GW). To uncover the key loci for these traits, we carried out a quantitative trait loci (QTL) analysis of an F6 recombinant inbred lines (RILs) population derived from a cross of Henong 5290 (small grain) and 06Dn23 (big grain) with a 50 K single nucleotide polymorphism (SNP) array. A total of 17 stable and big effect QTL, including 5 for TKW, 8 for GL and 4 for GW, were detected on the chromosomes 1B, 2A, 2B, 2D, 4B, 5A, 6A and 6D, respectively. Among these, there were two co-located loci for three traits that were mapped on the chromosome 4BS and 6AL. The QTL on 6AL was the most stable locus and explained 15.4-24.8%, 4.1-8.8% and 15.7-24.4% of TKW, GW and GL variance, respectively. In addition, two more major QTL of GL were located on chromosome arm 2BL and 2DL, accounting for 9.7-17.8% and 13.6-19.8% of phenotypic variance, respectively. In this study, we found one novel co-located QTL associated with GL and TKW in 2DL, QGl.haaf-2DL.2/QTkw.haaf-2DL.2, which could explain 13.6-19.8% and 9.8-10.7% phenotypic variance, respectively. Genetic regions and linked markers of these stable QTL will help to further refine mapping of the corresponding loci and marker-assisted selection (MAS) breeding for wheat grain yield potential improvement.

Improved monitoring of adherence with patching treatment using a microsensor and Eye Patch Assistant.

BACKGROUND: Use of a microsensor has been suggested to monitor patching adherence. Application has been limited because the microsensor's small size makes it easy to lose and a swallowing risk. We designed the Eye Patch Assistant (EPA) to hold the small microsensor in place and reduce the risk of loss or swallowing. This study reports the accuracy, precision, ease of use, and comfort for patching with EPA (patch+EPA) to monitor adherence. METHODS: Adults (N = 13) wore an adhesive patch alone or a patch+EPA for 2 hours each, recorded wear time, and completed an ease of use/comfort questionnaire; 30 children wore a patch or patch+EPA and completed the questionnaire. Sensor sampling interval was every 5 minutes or every 1 minute. Sensor accuracy and precision were evaluated by Bland-Altman analysis and 95% limits of agreement, and questionnaire scores compared by Wilcoxon tests. RESULTS: With 5-minute sampling, we found excellent accuracy for adults (mean actual vs recorded time difference, 1.4 minutes) and children (mean difference, -0.9 min). We found high precision for both adults and children (95% limits of agreement half widths of 6.4 minutes and 1.9 minutes, respectively). In adults, the ease of use score for the patch+EPA was lower than the patch (P < 0.01), but the comfort score for the patch+EPA was higher (P < 0.01). For children, scores did not differ significantly. The patch+EPA functioned well between 45° and 82°F. CONCLUSIONS: The patch+EPA was well accepted and monitored adherence accurately and precisely.

Aldehyde Dehydrogenase, Liver Disease and Cancer.

Acetaldehyde dehydrogenase 2 (ALDH2) is the key enzyme responsible for metabolism of the alcohol metabolite acetaldehyde in the liver. In addition to conversion of the acetaldehyde molecule, ALDH is also involved in other cellular functions. Recently, many studies have investigated the involvement of ALDH expression in viral hepatitis, alcoholic liver disease (ALD), non-alcoholic fatty liver disease (NAFLD), liver fibrosis, and liver cancer. Notably, ALDH2 expression has been linked with liver cancer risk, as well as pathogenesis and prognosis, and has emerged as a promising therapeutic target. Of note, approximately 8% of the world's population, and approximately 30-40% of the population in East Asia carry an inactive ALDH2 gene. This review summarizes new progress in understanding tissue-specific acetaldehyde metabolism by ALDH2 as well as the association of ALDH2 gene polymorphisms with liver disease and cancer. New research directions emerging in the field are also briefly discussed.

Inadequate ubiquitination-proteasome coupling contributes to myocardial ischemia-reperfusion injury.

The ubiquitin-proteasome system (UPS) degrades a protein molecule via 2 main steps: ubiquitination and proteasomal degradation. Extraproteasomal ubiquitin receptors are thought to couple the 2 steps, but this proposition has not been tested in vivo with vertebrates. More importantly, impaired UPS performance plays a major role in cardiac pathogenesis, including myocardial ischemia-reperfusion injury (IRI), but the molecular basis of UPS impairment remains poorly understood. Ubiquilin1 is a bona fide extraproteasomal ubiquitin receptor. Here, we report that mice with a cardiomyocyte-restricted knockout of Ubiquilin1 (Ubqln1-CKO mice) accumulated a surrogate UPS substrate (GFPdgn) and increased myocardial ubiquitinated proteins without altering proteasome activities, resulting in late-onset cardiomyopathy and a markedly shortened life span. When subject to regional myocardial ischemia-reperfusion, young Ubqln1-CKO mice showed substantially exacerbated cardiac malfunction and enlarged infarct size, and conversely, mice with transgenic Ubqln1 overexpression displayed attenuated IRI. Furthermore, Ubqln1 overexpression facilitated proteasomal degradation of oxidized proteins and the degradation of a UPS surrogate substrate in cultured cardiomyocytes without increasing autophagic flux. These findings demonstrate that Ubiquilin1 is essential to cardiac ubiquitination-proteasome coupling and that an inadequacy in the coupling represents a major pathogenic factor for myocardial IRI; therefore, strategies to strengthen coupling have the potential to reduce IRI.

The pathogenic gene screening in a Chinese familial dilated cardiomyopathy pedigree from Hubei.

Dilated cardiomyopathy arises from mutations in many genes. TTN, the gene encoding the sarcomere protein titin, has been insufficiently analyzed for cardiomyopathy mutations because of its enormous size. In this study, we report a Chinese family with two members affected by TTN. Blood samples were collected from all family members. Genomic DNA was isolated from blood, and all coding exons and adjacent intronic sequences of the TTN gene were examined for mutation analysis using polymerase chain reaction (PCR)-based sequencing. The proband (III3) and his sister (III2) carry a TTN c.100126A>G (p.Thr33376Ala) missense mutation. The proband currently exhibits decreased cardiac function accompanied by malignant arrhythmia, and his sister has no obvious clinical symptoms and no abnormal ultrasound findings. The study found that there is a missense mutation in the TTN gene, c.100126A>G (p.Thr33376Ala), in a family whose members suffer from familial dilated cardiomyopathy in Hubei province. TTN is closely related to dilated cardiomyopathy and is an important causative gene of familial dilated cardiomyopathy.

Novel imidazolium-embedded N,N-dimethylaminopropyl-functionalized silica-based stationary phase for hydrophilic interaction/reversed-phase mixed-mode chromatography.

A novel imidazolium-embedded N,N-dimethylaminopropyl-functionalized silica-based stationary phase (Sil-ImCl) was prepared and further used for hydrophilic interaction/reversed-phase mixed-mode chromatography. The Sil-ImCl stationary phase was respectively characterized by Fourier transform infrared spectrometry, thermogravimetric analysis, and element analysis. A variety of hydrophilic or hydrophobic compounds were used to evaluate the retention mechanisms of the developed stationary phase, and the effects of buffer salt concentration and pH of mobile phase on the retention of these compounds were also investigated. The developed stationary phase was successfully applied for separation of nucleosides and nucleic acid bases, water-soluble vitamins, phenols, and positional isomers. Moreover, simultaneous separation of polar and nonpolar compounds was also achieved with high resolution, outperforming the commercially available C8 column and amino column. Furthermore, the Sil-ImCl stationary phase has been successfully applied for separation of secondary metabolites of Hansfordia sinuosae. All these results demonstrate that the Sil-ImCl stationary phase might be promising for separation of complex polar and nonpolar compounds with high efficiency, especially in biological industry.

Effects of angiotensin-converting enzyme inhibition and bradykinin peptides in rats with myocardial infarction.

BACKGROUND AND OBJECTIVE: Angiotensin-converting enzyme (ACE) inhibitors have been reported to decrease myocardial remodeling and faciliate cardiac function improvement in the setting myocardial infarction by affecting bradykinin. The purpose of this study was to evaluate the combination effects of perindopril and bradykinin (BK) in rats with myocardial infarction. METHODS: Wistar Rats underwent to left anterior descending (LAD) coronary artery ligation were allocated into MI group (n=6); Perindopril group (n=7); Perindopril+BK group (n=7). An additional sham operation group (Sham group, n=6) were also established. After 4 weeks, the left ventricle function, myocardial tissue morphology, myocardial collagen volume faction, infracted ventricular wall thickness, myocardial infarction area and neovascular formation were evaluated. RESULTS: Combination treatment with perindopril and BK were showed significant improvement on LVEDV, LVEF and LVFS than MI group. Moreover, a significant improvement on LVEF was found in Perindopril+BK group than Perindopril group but not on LVEDV and LVFS between these two groups. Furthermore, neo-vessel density was significantly increased in Perindopril+BK group than other groups while no significant improvement on vessel density was found after the treatment of perindopril. In addition, myocardial infarction thickness improvement was found in Perindopril and group than MI group while combination treatment with perindopril and BK can significant improve the myocardial infarction thickness than perindopril only. CONCLUSIONS: Combination treatment with ACE inhibitor perindopril and BK can significantly improve the ventricle function in the rat model of myocardial infarction. Our data suggest BK can serve as adjuvant treatment in myocardial infarction treatment.

Atorvastatin improves microenvironment to enhance the beneficial effects of BMSCs therapy in a rabbit model of acute myocardial infarction.

BACKGROUND/AIMS: To investigate the beneficial effects of atorvastatin added to the cell therapy with bone marrow-derived mesenchymal stromal cells (BMSCs) in a rabbit model of acute myocardial infarction (AMI). METHODS: Rabbits were randomly divided into control group (n=10), bone marrow stem cells transplantation group (n=10), and BMSCs + atorvastatin group (n=10). AMI was established by ligating the left descending coronary artery. The left ventricular (LV) function was evaluated by echocardiography. H&E staining and Masson's Trichrome staining were performed to evaluate inflammatory cell infiltration and cardiac fibrosis. Immunohistochemistry and TUNEL were conducted to assess survival, differentiation, and apoptosis of transplanted cells and cardiomyocytes. RESULTS: BMSCs decreased LV systolic and diastolic diameters and increased LV ejection fractions, LV fractional shortening, LV systolic pressure and LV end-diastolic pressure. Atorvastatin synergistically enhanced the BMSCs-induced improvements of ischemic cardiac dysfunction. Atorvastatin reduced inflammatory cell infiltration, cardiac fibrosis, and derangement of myocardial morphology/structure. Atorvastatin added a protective effect to cardiomyocytes against apoptotic cell death in infarct and peri-infarct areas, and also increased the survival rate of implanted BMSCs in acute myocardial ischemia. Atorvastatin also promoted cardiac differentiation of implanted BMSCs in infarct myocardium. CONCLUSION: Atorvastatin acts to improve the microenvironment both by synergistically enhancing the existing effects of BMSCs and by adding new therapeutic effects to BMSCs transplantation, and this combinational therapy is a superior cell/pharmacological therapeutic approach that merits future preclinical and clinical studies.

HPV16 infection regulates RASSF1A transcription mediated by p53.

Human papillomavirus (HPV) 16 infection and RASSF1A expression play important roles in tumor development and progression. However, the precise mechanisms underlying their concerted function in the development of reproductive system tumors still remain to be elucidated. In the present study, we showed that HPV16-E6 selectively upregulates RASSF1A expression via degradation of p53, which interacts with the RASSF1A promoter and regulates apoptosis. Overexpression of p53 triggered a decrease in endogenous RASSF1A in SiHa cells, accompanied by apoptosis. Similarly, knockdown of endogenous HPV16-E6 in SiHa cells with RNA interference (RNAi) led to downregulation of RASSF1A mediated by p53 and the subsequent induction of apoptosis. These findings collectively suggest that HPV16 infection regulates p53-mediated RASSF1A expression and suppresses apoptosis. Moreover, RASSF1A may form an element of the negative autoregulatory feedback loops that act on the HPV16 response and are involved in p53-dependent apoptosis. Our results provide novel insights into the cellular mechanism of tumor development, and present a starting point for the development of novel strategies in cancer treatment and effective diagnosis.

Protective effects of trimetazidine on bone marrow mesenchymal stem cells viability in an ex vivo model of hypoxia and in vivo model of locally myocardial ischemia.

Bone marrow mesenchymal stem cells (MSCs) have shown potential for cardiac repair following myocardial injury, but this approach is limited by their poor viability after transplantation. The present study was to investigate whether trimetazidine (TMZ) could improve survival of MSCs in an ex vitro model of hypoxia, as well as survival, differentiation, and subsequent activities of transplanted MSCs in rat hearts with acute myocardial infarction (AMI). MSCs at passage 3 were examined for their viability and apoptosis under a transmission electron microscope, and by using flow cytometry following culture in serum-free medium and exposure to hypoxia (5% CO(2), 95% N(2)) for 12 h with or without TMZ. Thirty Wistar rats were divided into 3 groups (n=10 each group), including group I (AMI control), group II (MSCs transplantation alone), and group III (TMZ+MSCs). Rat MSCs (4×10(7)) were injected into peri-infarct myocardium (MSCs group and TMZ+MSCs group) 30 min after coronary artery ligation. The rats in TMZ+MSCs group were additionally fed on TMZ (2.08 mg·kg(-1)·day(-1)) from day 3 before AMI to day 28 after AMI. Cardiac structure and function were assessed by echocardiography at 28th day after transplantation. Blood samples were collected before the start of TMZ therapy (baseline), and 24 and 48 h after AMI, and inflammatory cytokines (CRP, TNF-α) were measured. Then the survival and differentiation of transplanted cells in vivo were detected by immunofluorescent staining. The cellular apoptosis in the peri-infarct region was detected by using TUNEL assay. Furthermore, apoptosis-related proteins (Bcl-2, Bax) within the post-infarcted myocardium were detected by using Western blotting. In hypoxic culture, the TMZ-treated MSCs displayed a two-fold decrease in apoptosis under serum-free medium and hypoxia environment. In vivo, cardiac infarct size was significantly reduced, and cardiac function significantly improved in MSCs and TMZ+MSCs groups as compared with those in the AMI control group. Combined treatment of TMZ with MSCs implantation demonstrated further decreased MSCs apoptosis, further increased MSCs viability, further decreased infarct size, and further improved cardiac function as compared with MSCs alone. The baseline levels of inflammatory cytokines (CRP, TNF-α) had no significant difference among the groups. In contrast, all parameters at 24 h were lower in TMZ+MSCs group than those in MSCs group. Furthermore, Western blotting indicated that the expression of anti-apoptotic protein Bcl-2 was up-regulated, while the pro-apoptotic protein Bax was down-regulated in the TMZ+MSCs group, compared with that in the MSCs group. It is suggested that implantation of MSCs combined with TMZ treatment is superior to MSCs monotherapy for MSCs viability and cardiac function recovery.

Protective Effects of Trimetazidine on Bone Marrow Mesenchymal Stem Cells Viability in an ex vivo Model of Hypoxia and in vivo Model of Locally Myocardial Ischemia / 华中科技大学学报（医学）（英德文版）

Bone marrow mesenchymal stem cells (MSCs) have shown potential for cardiac repair following myocardial injury,but this approach is limited by their poor viability after transplantation.The present study was to investigate whether trimetazidine (TMZ) could improve survival of MSCs in an ex vitro model of hypoxia,as well as survival,differentiation,and subsequent activities of transplanted MSCs in rat hearts with acute myocardial infarction (AMI).MSCs at passage 3 were examined for their viability and apoptosis under a transmission electron microscope,and by using flow cytometry following culture in serum-free medium and exposure to hypoxia (5％ CO2,95％ N2) for 12 h with or without TMZ.Thirty Wistar rats were divided into 3 groups (n=10 each group),including group Ⅰ (AMI control),group Ⅱ (MSCs transplantation alone),and group Ⅲ (TMZ+MSCs).Rat MSCs (4×107) were injected into peri-infarct myocardium (MSCs group and TMZ+MSCs group) 30 min after coronary artery ligation.The rats in TMZ+MSCs group were additionally fed on TMZ (2.08 mg·kg-1·day-1) from day 3 before AMI to day 28 after AMI.Cardiac structure and function were assessed by echocardiography at 28th day after transplantation.Blood samples were collected before the start of TMZ therapy (baseline),and 24 and 48 h after AMI,and inflammatory cytokines (CRP,TNF-α) were measured.Then the survival and differentiation of transplanted cells in vivo were detected by immunofluorescent staining.The cellular apoptosis in the peri-infarct region was detected by using TUNEL assay.Furthermore,apoptosis-related proteins (Bcl-2,Bax) within the post-infarcted myocardium were detected by using Western blotting.In hypoxic culture,the TMZ-treated MSCs displayed a two-fold decrease in apoptosis under serum-free medium and hypoxia environment.In vivo,cardiac infarct size was significantly reduced,and cardiac function significantly improved in MSCs and TMZ+MSCs groups as compared with those in the AMI control group.Combined treatment of TMZ with MSCs implantation demonstrated further decreased MSCs apoptosis,further increased MSCs viability,further decreased infarct size,and further improved cardiac function as compared with MSCs alone.The baseline levels of inflammatory cytokines (CRP,TNF-α) had no significant difference among the groups.In contrast,all parameters at 24 h were lower in TMZ+MSCs group than those in MSCs group.Furthermore,Western blotting indicated that the expression of anti-apoptotic protein Bcl-2 was up-regulated,while the pro-apoptotic protein Bax was down-regulated in the TMZ+MSCs group,compared with that in the MSCs group.It is suggested that implantation of MSCs combined with TMZ treatment is superior to MSCs monotherapy for MSCs viability and cardiac function recovery.

Floating matrix dosage form for dextromethorphan hydrobromide based on gas forming technique: in vitro and in vivo evaluation in healthy volunteers.

The objective of this study was to develop the dextromethorphan hydrobromide sustained-release (DMB-SR) tablets using floating technique to prolong the gastric residence time and compared their pharmacokinetic behavior with conventional sustained release tablets. DMB-SR floating tablets were prepared employing hydroxypropyl methylcellulose (HPMC) as hydrophilic gel material, sodium bicarbonate as gas-generating agent and hexadecanol as floating assistant agent. An orthogonal experiment design method was used to select the optimized formulation. The floating tablets were evaluated for uniformity of weight, hardness, friability, drug content, floating characteristics, in vitro release and in vivo bioavailability. The optimized tablets were prepared with HPMC K4M 25 mg, sodium bicarbonate 20 mg and hexadecanol 18 mg. The prepared tablets could float within 3 min and maintain for more than 24 h. The data of physical parameters were all lie within the limits. Drug release at 12 h was more than 85%. The comparative pharmacokinetic study was performed by administration of the DMB-SR floating tablets and conventional DMB-SR tablets. The area under curve of plasma concentration-time (AUC) of floating tablets was slightly higher than that of reference tablets, T(max) was prolonged apparently. The results showed the floating tablets are a feasible approach for the sustained-release preparation of drugs, which have limited absorption sites in the stomach.

Preparation of rosiglitazone maleate sustained-release floating microspheres for improved bioavailability.

The object of this study was to prepare rosiglitazone maleate (RM) sustained-release floating microspheres and investigate their pharmacokinetics. RM microspheres were prepared with ethyl cellulose (EC) and octadecyl alcohol as the carrier materials by an emulsion-solvent diffusion method, and the properties of morphology in vitro floating capability, drug loading (DL), entrapment efficiency (EE), in vitro release and in vivo pharmacokinetics were investigated. The prepared microspheres had a completely spherical shape. The percentage of microspheres floating after 12 h was (91.45 +/- 1.62)%, and the DL and EE were (9.31 +/- 0.31)% and (89.55 +/- 1.65)% respectively. Pharmacokinetic studies demonstrated that the RM floating microspheres were superior to commercial tablets in terms of the decrease in peak plasma concentration and maintenance of RM concentration in plasma. The area under the curve of plasma concentration-time (AUC) of the floating microspheres was equivalent to that of reference tablets. The results showed that floating microspheres are a feasible approach for the sustained-release preparation of drugs which have limited absorption sites in the upper small intestine.

Injectable hydrogel helps bone marrow-derived mononuclear cells restore infarcted myocardium.

BACKGROUNDS: Experimental and clinical studies have suggested that cell implantation could improve cardiac function after myocardial infarction (MI). However, this technique was limited by decreased engraftment and survival of transplanted cells within the ischemic tissue. The present study was performed to investigate whether implantation of bone marrow-derived mononuclear cells (BMMNCs) encapsulated in hydrogel could increase cell engraftment and help to restore cardiac function of MI rabbits. METHODS: MI was induced in rabbits by coronary artery ligation. One week later, cell culture medium, Dex-PCL-HEMA/PNIPAAm hydrogel, BMMNCs in medium or BMMNCs in hydrogel were injected into the infarcted area of the left ventricle (LV). RESULTS: Increased cell engraftment was observed 48 h after injection when cells were encapsulated in hydrogel; 30 days after treatment, echocardiographic studies showed that injection of BMMNCs in hydrogel preserved LV ejection fraction and attenuated LV dilatation compared with other groups. Histological analysis indicated that injection of BMMNCs in hydrogel enhanced neovascular formation and prevented scar expansion compared with the other groups. CONCLUSION: Injection of hydrogel-encapsulated BMMNCs increased cell engraftment and improved LV function; this technique may serve as an effective approach to restore infarcted myocardium.