Enhanced wound healing and hemostasis with exosome-loaded gelatin sponges from human umbilical cord mesenchymal stem cells.

BACKGROUND: Rapid wound healing remains a pressing clinical challenge, necessitating studies to hasten this process. A promising approach involves the utilization of human umbilical cord mesenchymal stem cells (hUC-MSCs) derived exosomes. The hypothesis of this study was that these exosomes, when loaded onto a gelatin sponge, a common hemostatic material, would enhance hemostasis and accelerate wound healing. AIM: To investigate the hemostatic and wound healing efficacy of gelatin sponges loaded with hUC-MSCs-derived exosomes. METHODS: Ultracentrifugation was used to extract exosomes from hUC-MSCs. Nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM), and western blot techniques were used to validate the exosomes. In vitro experiments were performed using L929 cells to evaluate the cytotoxicity of the exosomes and their impact on cell growth and survival. New Zealand rabbits were used for skin irritation experiments to assess whether they caused adverse skin reactions. Hemolysis test was conducted using a 2% rabbit red blood cell suspension to detect whether they caused hemolysis. Moreover, in vivo experiments were carried out by implanting a gelatin sponge loaded with exosomes subcutaneously in Sprague-Dawley (SD) rats to perform biocompatibility tests. In addition, coagulation index test was conducted to evaluate their impact on blood coagulation. Meanwhile, SD rat liver defect hemostasis model and full-thickness skin defect model were used to study whether the gelatin sponge loaded with exosomes effectively stopped bleeding and promoted wound healing. RESULTS: The NTA, TEM, and western blot experimental results confirmed that exosomes were successfully isolated from hUC-MSCs. The gelatin sponge loaded with exosomes did not exhibit significant cell toxicity, skin irritation, or hemolysis, and they demonstrated good compatibility in SD rats. Additionally, the effectiveness of the gelatin sponge loaded with exosomes in hemostasis and wound healing was validated. The results of the coagulation index experiment indicated that the gelatin sponge loaded with exosomes had significantly better coagulation effect compared to the regular gelatin sponge, and they showed excellent hemostatic performance in a liver defect hemostasis model. Finally, the full-thickness skin defect healing experiment results showed significant improvement in the healing process of wounds treated with the gelatin sponge loaded with exosomes compared to other groups. CONCLUSION: Collectively, the gelatin sponge loaded with hUC-MSCs-derived exosomes is safe and efficacious for promoting hemostasis and accelerating wound healing, warranting further clinical application.

Predictors of accurate intrapedicular screw placement in single-level lumbar (L4-5) fusion: robot-assisted pedicle screw, traditional pedicle screw, and cortical bone trajectory screw insertion.

BACKGROUND: The superiorities in proximal facet joint protection of robot-assisted (RA) pedicle screw placement and screw implantation via the cortical bone trajectory (CBT) have rarely been compared. Moreover, findings on the screw accuracy of both techniques are inconsistent. Therefore, we analyzed the screw accuracy and incidence of facet joint violation (FJV) of RA and CBT screw insertion in the same study and compared them with those of conventional pedicle screw (PS) insertion. The possible factors affecting screw accuracy and FJV were also analyzed. METHODS: A total of 166 patients with lumbar degenerative diseases requiring posterior L4-5 fusion were retrospectively included and divided into the RA, PS, and CBT groups from March 2019 to December 2021. The grades of intrapedicular accuracy and superior FJV were evaluated according to the Gertzbin-Robbins scale and the Babu scale based on postoperative CT. Univariable and multivariable analyses were conducted to assess the possible risk factors associated with intrapedicular accuracy and superior FJV. RESULTS: The rates of optimal screw insertion in the RA, PS, and CBT groups were 87.3%, 81.3%, and 76.5%, respectively. The difference between the RA and CBT groups was statistically significant (P = 0.004). Superior FJVs occurred in 28.2% of screws in RA, 45.0% in PS, and 21.6% in CBT. The RA and CBT groups had fewer superior FJVs than the PS group (P = 0.008 and P < 0.001, respectively), and no significant difference was observed between the RA and CBT groups (P = 0.267). Multivariable analysis revealed that the CBT technique was an independent risk factor for intrapedicular accuracy. Furthermore, older age, the conventional PS technique and a smaller facet angle were independently associated with the incidence of superior FJVs. CONCLUSIONS: The RA and CBT techniques were associated with fewer proximal FJVs than the PS technique. The RA technique showed a higher rate of intrapedicular accuracy than the CBT technique. The CBT technique was independently associated with screw inaccuracy. Older age, conventional PS technique and coronal orientation of the facet join were independent risk factors for superior FJV.

Empirical antibiotic treatment strategies for community-acquired pneumonia: a network meta-analysis.

OBJECTIVES: This network meta-analysis aimed to compare the efficacy and safety of fluoroquinolone (FQ) monotherapy, ß-lactam (BL) monotherapy and ß-lactam/macrolide (BL-M) combination therapy in hospitalized patients with community-acquired pneumonia (CAP). METHODS: Pubmed, Embase and the Cochrane Library were searched for randomized controlled trials (RCTs) comparing FQ monotherapy, BL monotherapy and BL-M combination therapy up to July 2021. The outcomes of interest included all-cause mortality, clinical success, microbiological success and drug-related adverse events. The summary relative risks (RRs) were estimated using pairwise and Bayesian network meta-analysis. RESULTS: A total of 12 RCTs involving 5009 patients were included. In pairwise meta-analysis, no significant differences were found among FQ monotherapy, BL monotherapy and BL-M dual therapy for all-cause mortality, clinical success or microbiological success. FQ monotherapy was associated with fewer adverse events compared with BL-M therapy (RR 0.80, 95% confidence interval [CI] 0.66-0.98). The network meta-analysis showed that there was no significant difference observed among FQ monotherapy, BL monotherapy and BL-M dual therapy regarding all the outcomes. CONCLUSION: FQ monotherapy, BL monotherapy and BL-M combination therapy demonstrated similar efficacy and safety for hospitalized patients with CAP in this network meta-analysis. Due to the limitations of quality and quantity of the included studies, it is difficult to make a definitive recommendation before more large-scale and high-quality RCTs are conducted.

[Chemical constituents from ethyl acetate extraction of Prunus mume].

Eight compounds were isolated from the ethyl acetate extraction of Prunus mume by column chromatography. On the basis of physicochemical properties and spectrum analysis, these compounds were identified as isoquercitrin-6″-O-benzoate(1), pinoresinol(2), naringin(3), ethyl-ß-D-glucopyranoside(4), astragalin(5), quercetin(6), hypericin(7), and rutin(8). Among them, compound 1 was a new natural product, and compounds 2-5 were isolated from this plant for the first time. In vitro study, compounds 1, 3, 5-8 could significantly increase the cell survival ratio.

One new benzophenone and one new 1,3-diphenylpropane from the fibrous roots of Anemarrhena asphodeloides Bge. and their cytotoxicity.

One new benzophenone (1) and one new 1,3-diphenylpropane (2) were obtained from the fibrous roots of Anemarrhena asphodeloides Bge. Their structures were determined by comprehensive 1D, 2D NMR and HRESIMS data. By comparing the calculated ECD curves and OR with the experimental data the absolute configurations were determined. The antitumor activity of all isolates was evaluated against two human hepatoma carcinoma cells (HepG2 and Hep3B) in vitro. The results demonstrated that compound 1 and 2 showed potent cytotoxicity against HepG2 and Hep3B cells.

Benzophenones from Anemarrhena asphodeloides Bge. Exhibit Anticancer Activity in HepG2 Cells via the NF-κB Signaling Pathway.

A chemical investigation of the fibrous roots of Anemarrhena asphodeloides Bge. led to the isolation of four benzophenones, including one new compound (1) and three known ones (2-4). Comprehensive 1D, 2D NMR and HRESIMS data established the structures of the isolated compounds. The absolute configurations were determined by comparison of the calculated optical rotation (OR) with experimental data. All the isolates were evaluated for their cytotoxicities on hepatocellular carcinoma cell lines (HepG2 and Hep3B). Compound 1 showed strong cytotoxicity against HepG2 and Hep3B cells, with IC50 values at 153.1 and 180.6 nM. Through MTT assay, flow cytometry and Western blot analysis, compound 1 demonstrated the ability to stimulate apoptosis via the NF-κB signaling pathway in HepG2 cells. These benzophenones are potential lead compounds for the development of better treatments for hepatocellular carcinoma.

Hypercholesterolemic myocardium is vulnerable to ischemia-reperfusion injury and refractory to sevoflurane-induced protection.

Recent studies have demonstrated that volatile anesthetic postconditioning confers myocardial protection against ischemia-reperfusion (IR) injury through activation of the reperfusion injury salvage kinase (RISK) pathway. As RISK has been shown to be impaired in hypercholesterolemia. Therefore, we investigate whether anesthetic-induced cardiac protection was maintained in hypercholesterolemic rats. In the present study, normocholesteolemic or hypercholesterolemic rat hearts were subjected to 30 min of ischemia and 2 h of reperfusion. Animals received 2.4% sevoflurane for 5 min or 3 cycles of 10-s ischemia/10-s reperfusion. The hemodynamic parameters, including left ventricular developed pressure, left ventricular end-diastolic pressure and heart rate, were continuously monitored. The infarct size, apoptosis, p-Akt, p-ERK1/2, p-GSK3ß were determined. We found that both sevoflurane and ischemic postconditioning significantly improved heart pump function, reduced infarct size and increased the phosphorylation of Akt, ERK1/2 and their downstream target of GSK3ß in the healthy rats. In the hypercholesterolemic rats, neither sevoflurane nor ischemic postconditioning improved left ventricular hemodynamics, reduced infarct size and increased the phosphorylated Akt, ERK1/2 and GSK3ß. In contrast, GSK inhibitor SB216763 conferred cardioprotection against IR injury in healthy and hypercholesterolemic hearts. In conclusions, hyperchoesterolemia abrogated sevoflurane-induced cardioprotection against IR injury by alteration of upstream signaling of GSK3ß and acute GSK inhibition may provide a novel therapeutic strategy to protect hypercholesterolemic hearts against IR injury.

Activation of Akt and cardioprotection against reperfusion injury are maximal with only five minutes of sevoflurane postconditioning in isolated rat hearts.

It had been proved that administration of sevoflurane for the first two minutes of reperfusion effectively protects the heart against reperfusion injury in rats in vivo. Our aim was to investigate the duration of effective sevoflurane administration and its underlying mechanism in isolated rat hearts exposed to global ischemia/reperfusion (I/R) injury. Adult male Sprague-Dawley rats were randomly divided into six groups (n=12): a sham-operation group, an I/R group, and four sevoflurane postconditioning groups (S2, S5, S10, and S15). In the S2, S5, S10, and S15 groups, the duration times of sevoflurane administration were 2, 5, 10, and 15 min after the onset of reperfusion, respectively. The isolated rat hearts were mounted on the Langendorff system, and after a period of equilibrium were subjected to 40 min global ischemia and 120 min reperfusion. Left ventricular (LV) hemodynamic parameters were monitored throughout each experiment and the data at 30 min of equilibrium and 30, 60, 90, and 120 min of reperfusion were analyzed. Myocardial infarct size at the end of reperfusion (n=7 in each group) and the expression of myocardial phosphorylated Akt (p-Akt) after 15-min reperfusion were determined in a duplicate set of six groups of rat hearts (n=5 in each group). Compared with the I/R group, the S5, S10, and S15 groups had significantly improved left ventricular end-diastolic pressure (LVEDP), left ventricular developed pressure (LVDP), and the maximal rate of rise or fall of the LV pressure (±dP/dtmax), and decreased myocardial infarct size (P<0.05), but not the S2 group. After 15 min of reperfusion, the expression of p-Akt was markedly up-regulated in the S5, S10, and S15 groups compared with that in the I/R group (P<0.05), but not in the S2 group. Sevoflurane postconditioning for 5 min was sufficient to activate Akt and exert maximal cardioprotection against I/R injury in isolated rat hearts.

Both PI3K/Akt and ERK1/2 pathways participate in the protection by dexmedetomidine against transient focal cerebral ischemia/reperfusion injury in rats.

Dexmedetomidine (Dex) has been demonstrated to provide neuroprotection against ischemia/reperfusion (I/R) injury. However, the exact mechanism of this protection remains unknown. Here, we explored the neuroprotective effect of Dex in rats exposed to cerebral I/R-induced by middle cerebral artery occlusion (MCAO) and the role of phosphatidylinositol 3-kinase (PI3K)/Akt, extracellular signal-regulated kinase 1/2 (ERK1/2), and glycogen synthase kinase-3ß (GSK-3ß) in this protective action. Adult male Sprague-Dawley rats were subjected to MCAO for 90 min followed by reperfusion for 24h and Dex (15 µg/kg, i.v.) was administered immediately after the onset of MCAO. The neurological deficit score, cerebral infarct volume, brain edema, and neuron survival were evaluated at 24h of reperfusion. The effect of Dex on p-Akt, p-ERK1/2 and p-GSK-3ß expression in the ischemic hemisphere was assayed by Western blot. Treatment of rats exposed to I/R with Dex caused not only marked reduction in the neurological deficit score, cerebral infarct volume, and brain edema (P <0.01 vs. I/R alone), but also a decrease in neuron death in hippocampal CA1 and cortex (P<0.01 vs. I/R alone). The Dex-induced increment of neuron survival in the ischemic CA1 and cortex was diminished by the PI3K inhibitor LY294002 and the MEK inhibitor U0126. The increasing expressions of p-Akt and p-ERK1/2 induced by Dex in the ischemic hemisphere were markedly inhibited by LY294002 (or wortmannin) and U0126 (or PD98059), respectively. The up-regulation of p-GSK-3ß by Dex in the ischemic hemisphere was significantly decreased by both LY294002 (or wortmannin) and U0126 (or PD98059). Our data demonstrated that treatment with Dex reduced cerebral injury in rats exposed to transient focal I/R, and this was mediated by the activation of the PI3K/Akt and ERK1/2 pathways as well the phosphorylation of downstream GSK-3ß.