Mechanical properties and immunotherapeutic effects of dissolving microneedles with different drug loadings based on hyaluronic acid

Abstract Improving vaccine immunity and reducing antigen usage are major challenges in the clinical application of vaccines. Microneedles have been proven to be painless, minimally invasive, highly efficient, and have good patient compliance. Compared with traditional transdermal drug delivery, it can effectively deliver a large-molecular-weight drug into the skin, resulting in a corresponding immune response. However, few studies have examined the relationship between microneedle loading dose and immune effects. In this study, the hyaluronic acid (HA) conical and pyramidal dissolving microneedles were prepared by the two-step vacuum drying method, respectively. The model drug ovalbumin (OVA) was added to HA to prepare dissolving microneedles with different loading amounts. The mass ratios of HA to OVA were 5:1, 5:3, and 5:5. The mechanical properties of the dissolving microneedles were characterized using nanoindentation and in vitro puncture studies. The immune effects of the matrix and drug content were studied in Sprague-Dawley (SD) rats. Finally, the diffusion behavior of OVA and the binding mode of HA and OVA in the microneedles were simulated using Materials Studio and Autodocking software. The experimental results showed that the conical microneedles exhibited better mechanical properties. When the mass ratio of HA to OVA was 5:3, the immune effect can be improved by 37.01% compared to subcutaneous injection, and achieved a better immune effect with relatively fewer drugs. This conclusion is consistent with molecular simulations. This study provides theoretical and experimental support for the drug loading and efficacy of microneedles with different drug loadings

Atractylenolide Ⅰ improves acetaminophen-induced acute liver injury in mice by inhibiting MAPK/NF-κB signaling pathway / 中国中药杂志

This study explored the protective effect of atractylenolide Ⅰ(AO-Ⅰ) against acetaminophen(APAP)-induced acute liver injury(ALI) in mice and its underlying mechanism. C57 BL/6 J mice were randomly divided into a control group, an APAP group(500 mg·kg~(-1)), a low-dose combination group(500 mg·kg~(-1) APAP + 60 mg·kg~(-1) AO-Ⅰ), and a high-dose combination group(500 mg·kg~(-1) APAP + 120 mg·kg~(-1) AO-Ⅰ). ALI was induced by intraperitoneal injection of APAP(500 mg·kg~(-1)). AO-Ⅰ by intragastric administration was performed 2 hours before APAP treatment, and the control group received the same dose of solvent by intragastric administration or intraperitoneal injection. The protective effect of AO-Ⅰ against APAP-induced ALI was evaluated by detecting alanine aminotransferase(ALT) and aspartate aminotransferase(AST) levels in the plasma and H&E staining in liver tissues of mice. The malondialdehyde(MDA) and glutathione(GSH) content and catalase(CAT) activity in mouse liver tissues were detected to evaluate the effect of AO-Ⅰ on APAP-induced oxidative stress in the liver. The proteins in the liver p38 mitogen-activated protein kinase(p38 MAPK), c-jun N-terminal kinase(JNK), and nuclear factor kappa-B p65(NF-κB p65) signaling pathways were measured by Western blot, and the liver inflammatory cytokines interleukin-1β(IL-1β) and interleukin-6(IL-6) were detected by real-time PCR. Compared with the APAP group, the combination groups showed reduced APAP-induced ALT level and liver MDA content, potentiated liver CAT activity, and elevated GSH content. Mechanistically, AO-Ⅰ treatment significantly inhibited APAP-up-regulated MAPK phosphorylation and NF-κB p65, and significantly reduced the transcriptional activities of IL-1β and IL-6, downstream targets of NF-κB p65. AO-Ⅰ can improve APAP-induced ALI and the underlying mechanism is related to the inhibition of the MAPK/NF-κB p65 signaling pathway in APAP-challenged mice.

Role of vascular cell adhesion molecule-1 in the mouse model of hepatic ischemia/reperfusion and the hematogenic metastasis / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the effect of ischemia/reperfusion (I/R) on tumor metastasis in a experimental mouse model of hematogenous metastasis after I/R and to quantify expression of vascular cell adhesion molecule-1 (VCAM-1) during I/R.</p><p><b>METHODS</b>An experimental mouse model of metastasis after partial hepatic I/R was designed to determine the effects of I/R on tumor metastasis to liver. Tumor loads were valued 14 days after operation. In addition, the expressions of alanine transaminase (ALT), aspartate transaminase (AST), and VCAM-1 were detected.</p><p><b>RESULTS</b>Two hours after hepatic reperfusion, ALT and AST levels in ischemia 45-minute group and ischemia 30-minute group were significantly higher than in the sham group (all P < 0.05). Also, the changes of ALT and AST were more obvious in the ischemia 45-minute group than in ischemia 30-minute group (all P < 0.05). In the sham group, both ALT and AST slightly and transiently increased. ALT and AST in the ischemia 45-minute group and ischemia 30-minute group at 8 hours were both significantly higher than those at 2 hours reperfusion (P<0.05). The tumor load (valued by hepatic replacement area) and the expression of VCAM-1 in ischemic lobe were significantly larger in the ischemia 45-minute group than in the ischemia 30-minute group and sham group (P = 0.013, P = 0.007). However, there was no statistical difference on tumor load between the right lobe of sham operated mice and the right lobe (nonischemic lobes) of mice subjected to I/R (P = 0.089). Mouse survivals were significantly longer in the sham group than in the ischemia 30-minute group (P = 0.041) but were not significantly different between the ischemia 45-minute group and ischemia 30-minute group (P = 0.055). VCAM-1 expression in ischemia 45-minute group was significantly higher than in ischemia 30-minute group and sham group(P = 0.003, P < 0.001), and it was positively correlated with the hepatic replacement area (r = 0.491, P = 0.045).</p><p><b>CONCLUSION</b>Hepatic I/R promotes liver hematogenic metastasis of hepatocellular carcinoma in mice and at least in part, through the induction of VCAM-1 expression.</p>

Analysis of phage Mu DNA transposition by whole-genome Escherichia coli tiling arrays reveals a complex relationship to distribution of target selection protein B, transcription and chromosome architectural elements.

Of all known transposable elements, phage Mu exhibits the highest transposition efficiency and the lowest target specificity. In vitro, MuB protein is responsible for target choice. In this work, we provide a comprehensive assessment of the genome-wide distribution of MuB and its relationship to Mu target selection using high-resolution Escherichia coli tiling DNA arrays. We have also assessed how MuB binding and Mu transposition are influenced by chromosome-organizing elements such as AT-rich DNA signatures, or the binding of the nucleoid-associated protein Fis, or processes such as transcription. The results confirm and extend previous biochemical and lower resolution in vivo data. Despite the generally random nature of Mu transposition and MuB binding, there were hot and cold insertion sites and MuB binding sites in the genome, and differences between the hottest and coldest sites were large. The new data also suggest that MuB distribution and subsequent Mu integration is responsive to DNA sequences that contribute to the structural organization of the chromosome.

Impact of magnetic field exposure on cardiac autonomic tone and inducibility of atrial fibrillation in dogs / 中华心血管病杂志

<p><b>OBJECTIVE</b>To observe the maximal heart rate changes, atrioventricular (A-V) conduction block and atrial fibrillation (AF) inducibility in dogs with vagosympathetic trunk exposed to electromagnetic fields (EMFs).</p><p><b>METHODS</b>The vagosympathetic trunk of adult dogs was separated and exposed to EMFs 0.043 kHz (2.87 microG, n = 5) and to EMFs 2 kHz (0.34 microG, n = 6) for two to three hours. Simultaneously, the vagosympathetic trunk was stimulated with 20 Hz frequency and 1 - 8 V intensity for 0.1 ms. Heart rate, presence of A-V conduction block and AF inducibility were determined.</p><p><b>RESULTS</b>After 5-minutes exposure to EMFs 0.043 kHz (2.87 microG), the maximal heart rate decreased 29%, the voltage applied to vagosympathetic trunk required to induce A-V conduction block decreased by 60% in experimental group versus 5% increase in control group. This effect lasted 2 to 3 hours. While vagosympathetic trunk exposure to EMFs 2 kHz (0.34 microG) was associated with significant increase in the incidence of atrial premature beats, atrial tachycardia and AF, these effects could be blocked by propranolol and atropine.</p><p><b>CONCLUSIONS</b>Our results showed that 0.043 kHz (2.87 microG) EMFs exposure might reduce while 2 kHz (0.34 microG) EMFs exposure might increase AF inducibility. Our study thus suggested autonomic nervous system of dogs could be affected by EMFs exposure and 0.043 kHz (2.87 microG) EMFs exposure might be a novel option for AF prevention.</p>

Efficacy of sequential ablation of sinus atrial node fat pad and atrial ventricular node fat pad on inducibility of atrial fibrillation evoked by vagus trunk stimulation / 中华心血管病杂志

<p><b>OBJECTIVE</b>To explore the efficacy of sequential ablation of epicardial fat pad on inducibility of atrial fibrillation (AF) evoked by stimulating vagus trunk.</p><p><b>METHODS</b>Eighteen adult mongrel dogs were randomly divided into 2 groups (n = 9 each): Group A underwent pre-ablation of sinus-atrial node fad pad (SANFP) and subsequent ablation of atria-ventricular node fad pad (AVNFP). Group B underwent pre-ablation of AVNFP and subsequent ablation of SANFP. AF was induced by high-frequency electrical stimulation of bilateral vagus trunks. The AF inducibility and effective refractory period (ERP) changes during vagus trunk stimulation were examined before and after ablation in atria and pulmonary veins.</p><p><b>RESULTS</b>(1) AF could be induced by vagus trunk stimulation and the incidence was higher during right vagus trunk (RVG) stimulation than left vagus trunk (LVG) stimulation [(60.0 ± 0.0)% vs (18.4 ± 22.1)%]. (2) SANFP ablation significantly attenuated AF inducibility with LVG stimulation and RVG stimulation at 2 V (decreased 67.0% and 72.0%, respectively). Subsequent AVNFP ablation after SANFP ablation further reduced AF inducibility with LVG and RVG stimulation at 2 V (decreased 100.0% and 95.5%, respectively). (3) AVNFP ablation (decreased 95.7% and 96.3%, respectively) and subsequent SANFP ablation after AVNFP ablation (decreased 98.0% and 100.0%, respectively) significantly attenuated AF inducibility with LVG stimulation and RVG stimulation at 2V. (4) Vagal stimulation induced ERP shortening was significantly attenuated by isolated SANFP ablation or AVNFP. Subsequent AVNFP ablation after SANFP induced significant ERP shortening in right atrial site compared with isolated SANFP ablation. However, changes of ERP shortening were similar between AVNFP ablation and subsequent SANFP ablation after AVNFP ablation.</p><p><b>CONCLUSIONS</b>Epicardial fat pad ablation reduced the AF inducibility and prolonged ERP of atria and pulmonary veins during vagus trunk stimulation. AVNFP, as the "integration centers" modulating the vagal innervation to the atria, may be the more effective target of ablation for treating AF.</p>

Metal stress-induced arrhythmia and thoracic spinal cord 1-5 nerve remodeling and myocardial electrophysiological remodeling in rats / 中华心血管病杂志

<p><b>OBJECTIVE</b>The study aimed to investigate the relationship between arrhythmia occurrence and nerve remodeling of thoracic spinal cord 1-5 nerves as well as myocardial electrophysiological remodeling in a metal stress rat model.</p><p><b>METHODS</b>Thirty SD rats (weight 180-250 g) were randomly divided into control group (n = 10), stress group (n = 10) and fluoxetine group (n = 10, 10 mg/kg i.p. for 3 weeks). Stress model (given by unpredicted chronic mild stress) was established according to Cronli's protocol. Following parameters were observed:(1) ECG waveform change and arrhythmias;(2) tissue field action potential duration (FAPD) of thoracic spinal cord 1-5 and cardiac tissue mapped by microelectrode arrays (MEA) technique;(3) myocardial growth-associated protein (GAP-43), tyrosine hydroxylase (TH), choline acetyltransferase (CHAT) distribution observed by immunofluorescence and confocal laser scanning microscope (LSCM).</p><p><b>RESULTS</b>Three weeks later: (1) The body weight, food intake, consumption of sugar water, the horizontal and vertical movement score, cleaning action of rats were significantly decreased, and fecal grains significantly increased, P-wave, P-R interval, QRS-wave and Q-T interval were significantly prolonged and heart rate was significantly reduced in stress group compared with control group (all P < 0.05). Incidence of ventricular premature beat was 80% in stress group and 0% in control group (P < 0.05). The FAPD of thoracic spinal cord 1-5 nerves [(144.25 ± 12.63)ms vs (79.56 ± 8.01)ms] and of cardiac tissue [LA(122.43 ± 19.34)ms vs (92.59 ± 7.61)ms, RA(149.89 ± 14.68)ms vs (105.18 ± 15.94)ms, LV(162.62 ± 7.04)ms vs (110.45 ± 6.92)ms, RV(152.21 ± 30.49)ms vs (131.06 ± 12.04)ms] were significantly prolonged, FAPD dispersion (FAPDd) significantly increased [thoracic spinal cord 1-5(13.3 ± 9.11)ms vs (9.36 ± 7.01)ms] in stress group compared with the control group. Disarrangement of myocardial cells, proliferation of collagen fiber, infiltration of neutrophil and lymphocytes in the cardiac tissue were also observed and distribution of GAP-43, TH and CHAT was significantly increased in stress group. (2) All these changes could be partly reversed by the treatment with fluoxetine.</p><p><b>CONCLUSION</b>Metal stress induced cardiac autonomic nerve and myocardial electrophysiological remodeling and ventricular arrhythmia in rats which could be significantly attenuated by fluoxetine in this model.</p>

Body mass index of male youths aged 18-20 years of the Han nationality living in different regions of China.

The study was conducted to assess the nutritional status and levels of body mass index (BMI, kg/m2) and to evaluate the geographical distribution of male youths of the Han nationality in China. In total, 60,773 male youths, aged 18-20 years, of the Han nationality, were categorized into underweight, normal-weight, overweight, and obesity according to the international adult BMI cut-offs. Different levels of nutritional status and BMI of male youths of the Han nationality were compared among different areas. The mean BMI for the whole country was 20.6 in urban areas and 20.0 in rural areas. BMI increased from 20.1 among 18-year old youths to 20.5 among 20-year old youths. The prevalence of underweight among the male youths was 21.6%, while the prevalence of overweight and obesity were 4.6% and 0.6% respectively. For urban youths, the prevalence of underweight, overweight, and obesity were 21.0%, 6.8%, and 1.1% respectively, while these were, respectively, 21.9%, 3.3%, and 0.3% for rural youths. The nutritional status of the male youths in North-China was at the highest level (21.1) among the six areas, and the prevalence of underweight, overweight, and obesity were 14.3%, 9.1%, and 1.4% respectively. The highest prevalence of underweight was 29.8% in the North-West region, and the lowest prevalence of overweight was 2.2% in the South-Middle region, while the lowest prevalence of obesity was 0.2% in the South-West region. The nutritional status of the male youths was significantly different among different areas. Underweight was still prevalent in all male youth groups. Nonetheless, overweight was more prevalent among urban youths than among rural youths and was more prevalent in the North region than in the South region.