The aim of this study was to investigate the contribution of lung zinc ions to pathogenesis of lung ischemia/reperfusion (I/R) injury in rats. Male Sprague Dawley (SD) rats were randomly divided into control group, lung I/R group (I/R group), lung I/R + low-dose zinc chloride group (LZnCl₂+I/R group), lung I/R + high-dose ZnCl₂ group (HZnCl₂+I/R group), lung I/R + medium-dose ZnCl₂ group (MZnCl₂+I/R group) and TPEN+MZnCl₂+I/R group (n = 8 in each group). Inductively coupled plasma mass spectrometry (ICP-MS) was used to measure the concentration of zinc ions in lung tissue. The degree of lung tissue injury was analyzed by observing HE staining, alveolar damage index, lung wet/dry weight ratio and lung tissue gross changes. TUNEL staining was used to detect cellular apoptosis in lung tissue. Western blot and RT-qPCR were used to determine the protein expression levels of caspase-3 and ZIP8, as well as the mRNA expression levels of zinc transporters (ZIP, ZNT) in lung tissue. The mitochondrial membrane potential (MMP) of lung tissue was detected by JC-1 MMP detection kit. The results showed that, compared with the control group, the lung tissue damage, lung wet/dry weight ratio and alveolar damage index were significantly increased in the I/R group. And in the lung tissue, the concentration of Zn²⁺ was markedly decreased, while the cleaved caspase-3/caspase-3 ratio and apoptotic levels were significantly increased. The expression levels of ZIP8 mRNA and protein were down-regulated significantly, while the mRNA expression of other zinc transporters remained unchanged. There was also a significant decrease in MMP. Compared with the I/R group, both MZnCl₂+I/R group and HZnCl₂+I/R group exhibited significantly reduced lung tissue injury, lung wet/dry weight ratio and alveolar damage index, increased Zn²⁺ concentration, decreased ratio of cleaved caspase-3/caspase-3 and apoptosis, and up-regulated expression levels of ZIP8 mRNA and protein. In addition, the MMP was significantly increased in the lung tissue. Zn²⁺ chelating agent TPEN reversed the above-mentioned protective effects of medium-dose ZnCl₂ on the lung tissue in the I/R group. The aforementioned results suggest that exogenous administration of ZnCl₂ can improve lung I/R injury in rats.
Animals ; Reperfusion Injury/pathology* ; Male ; Rats, Sprague-Dawley ; Rats ; Chlorides/administration & dosage* ; Lung/pathology* ; Zinc Compounds/administration & dosage* ; Apoptosis/drug effects* ; Caspase 3/metabolism* ; Cation Transport Proteins/metabolism*

In this study, we explored the pharmacological effects of Siwu Decoction in treating premature ovarian insufficiency(POI) and its molecular mechanism based on the mitophagy pathway modulated and mediated by estrogen receptor(ER) subtypes. Female Balb/c mice were divided into a control group, model group, as well as high-dose and low-dose groups of Siwu Decoction. The POI mice model was constructed by intraperitoneal injection of cisplatin. The high-dose and low-dose groups of Siwu Decoction were administered intragastrically with Siwu Decoction each day for 14 days. During this period, we monitored the estrous cycle and body weight of the mice and calculated the ovarian index. The morphology of the ovaries was detected by hematoxylin-eosin(HE) staining, and the number of primordial follicles was counted. The apoptosis of the ovarian tissue was detected by TUNEL staining. The expression levels of anti-Müllerian hormone(AMH), apoptosis-associated and mitophagy-associated proteins, ER subtypes, and the expression levels of key proteins of its mediated molecular pathways were detected by Western blot and immunohistochemistry. KGN cells were divided into a control group, model group, Siwu Decoction group, and gene silencing group. The apoptosis model was induced by H_2O_2, and PTEN-induced putative kinase 1(PINK1) gene silencing was induced by siRNA transfection. The Siwu Decoction group and gene silencing group were added to the medium containing Siwu Decoction. Cell viability was detected by CCK-8 assay. Cell senescence was detected by senescence-associated-β-galactosidase. The expression levels of apoptosis-associated and mitophagy-associated proteins were detected by Western blot. The results of in vivo experiments showed that compared with the model group, the mice in the high-dose and low-dose groups of Siwu Decoction significantly recovered the rhythm of the estrous cycle, and the levels of ovarian index, number of primordial follicles, and expression of AMH, representative indexes of ovarian function, were significantly higher, suggesting that the level of ovarian function was significantly improved. The expression levels of the apoptosis-related proteins, cytochrome C(Cyt C), cysteinyl aspartate specific proteinase 3(caspase 3), B-cell lymphoma-2(Bcl-2)-associated X(Bax), and mitophagy-associated indicator(Beclin 1) were significantly decreased, and the expression levels of Bcl-2 was significantly elevated. The positive area of TUNEL was significantly reduced, suggesting that the apoptosis level of the ovaries was significantly reduced. The expression levels of PINK1, Parkin, and sequestosome 1(p62) were significantly reduced, suggesting that the level of ovarian mitophagy was significantly down-regulated. The expression levels of ERα and ERβ were significantly elevated, and the ratio of ERα/ERβ was significantly reduced. The expression levels of key proteins in the pathway, phosphoinositide 3-kinase(PI3K) and protein kinase B(Akt), were significantly reduced, suggesting that the regulation of ER subtypes and the mediation of PI3K/Akt pathway were the key mechanisms. In vitro experiments showed that compared with the model group, the proportion of senescent cells in the Siwu Decoction group was significantly reduced. Cyt C, caspase 3, Beclin 1, Parkin, and p62 were significantly reduced, which was in line with in vivo experimental results. The proportion of senescent cells and the expression level of the above proteins were further significantly reduced after PINK1 silencing. It can be seen that Siwu Decoction can regulate the expression level and proportion of ER subtypes in KGN cells, then mediate the PI3K/Akt pathway to inhibit excessive mitophagy and apoptosis, and exert therapeutic effects of POI.
Animals ; Female ; Drugs, Chinese Herbal/administration & dosage* ; Mitophagy/drug effects* ; Primary Ovarian Insufficiency/physiopathology* ; Mice ; Mice, Inbred BALB C ; Humans ; Receptors, Estrogen/genetics* ; Apoptosis/drug effects* ; Ovary/metabolism* ; Signal Transduction/drug effects* ; Anti-Mullerian Hormone/genetics*

The continuous emergence of SARS-CoV-2 variants as well as other potential future coronavirus has challenged the effectiveness of current COVID-19 vaccines. Therefore, there remains a need for alternative antivirals that target processes less susceptible to mutations, such as the formation of six-helix bundle (6-HB) during the viral fusion step of host cell entry. In this study, a novel high-throughput screening (HTS) assay employing a yeast-two-hybrid (Y2H) system was established to identify inhibitors of HR1/HR2 interaction. The compound IMB-9C, which achieved single-digit micromolar inhibition of SARS-CoV-2 and its Omicron variants with low cytotoxicity, was selected. IMB-9C effectively blocks the HR1/HR2 interaction in vitro and inhibits SARS-CoV-2-S-mediated cell-cell fusion. It binds to both HR1 and HR2 through non-covalent interaction and influences the secondary structure of HR1/HR2 complex. In addition, virtual docking and site-mutagenesis results suggest that amino acid residues A930, I931, K933, T941, and L945 are critical for IMB-9C binding to HR1. Collectively, in this study, we have developed a novel screening method for HR1/HR2 interaction inhibitors and identified IMB-9C as a potential antiviral small molecule against COVID-19 and its variants.

Objective To observe the effect of Ginkgo biloba extract(GBE)on depression like behavior in post stroke depression(PSD)model rats,and explore the mechanism of regulating Toll like receptor 4/nuclear factor-κ B(TLR4/NF-κB)pathway to inhibit neuroinflammation.Methods Rats were randomly divided into 6 groups,sham,cerebral ischemia,PSD,paroxetine,low-dose Ginkgo biloba extract(GBE-L)and high-dose Ginkgo biloba extract(GBE-H)groups,10 rats in each group.Except for the sham group,middle cerebral artery occlusion(MCAO)was performed to prepare a left focal cerebral ischemia model.Except for the sham group and cerebral ischemia group,other groups were subjected to chronic unpredictable mild stress(CUMS)to establish PSD rat model for 8 weeks.After 4 weeks of CUMS,the paroxetine group,GBE-L,and GBE-H were treated with paroxetine 5 mg·kg-1,GBE 50 mg·kg-1,and GBE 100 mg·kg-1,respectively.The sham group,cerebral ischemia group,and PSD group were treated with the same volume of 0.9％NaCl and continuously administered by gavage for 28 d.After 4 weeks and 8 weeks of CUMS,the body weight and sugar preference test were measured.Levels of serum tumor necrosis factor-α(TNF-α),interleukin-1 β(IL-1 β)and levels of norepinephrine(NE),serotonin(5-HT),and dopamine(DA)in the cerebral cortex were measured by enzyme-linked immunosorbent assay(ELISA).The mRNA levels of Tlr4,Nfkb1,and nuclear factor κ B-kinase subunit β inhibitory factor(Ikbkb)in the hippocampus of rats were detected by polymerase chain reaction.The protein levels of NF-κB,nuclear factor κB inhibitory protein α(IKBα)and phosphorylation nuclear factor κB inhibitory protein α(p-IKB)in hippocampal tissue were detected by Western blot.Results The body weights of rats in the sham group,cerebral ischemia group,PSD group,paroxetine group,GBE-L group and GBE-H group were(427.10±6.36),(403.10±7.37),(310.10±9.71),(355.00±4.03),(347.90±9.88)and(391.90±5.07)g;sugar preference rate were(93.93±1.78)％,(91.57±1.03)％,(54.72±7.34)％,(88.35±4.36)％,(63.55±12.73)％and(81.04±4.31)％;the levels of NE in the cerebral cortex were(1 951.14±52.86),(1 827.27±23.63),(1 662.12±35.92),(2 033.58±72.28),(1 887.31±33.07)and(2 175.00±42.54)pg·mL-1;the levels of 5-HT in the cerebral cortex were(237.07±8.86),(226.15±10.27),(214.51±3.46),(297.13±5.79),(274.14±7.63)and(285.34±8.72)ng·mL-1;the levels of DA in the cerebral cortex were(1 531.11±47.26),(1 209.89±58.09),(1 143.15±36.31),(1 812.67±51.28),(1 651.56±31.82)and(1 853.33±20.42)pg·mL-1.Compared with the PSD group,GBE significantly increased the body weight of rats(P＜0.01)and increased the preference rate of sugar water in rats,showing the antidepressant like behavioral.GBE significantly reduced the levels of serum TNF-α,IL-1 β(all P＜0.01),increased the levels of NE,5-HT,and DA in the cerebral cortex(all P＜0.01),down regulate the mRNA levels of Tlr4,Nfkb1 and Ikbkb(P＜0.05,P＜0.01),reduced the expression of NF-κB(P＜0.01),and reduced the phosphorylation of IKBα(P＜0.01).Conclusion Ginkgo biloba extract can improve depression-like behavior in PSD model rats,and has antidepressant effect.Its mechanism is related to the inhibition of TLR4/NF-κB pathway,thus reducing neuroinflammation.

Objective To analyze the characteristics of adult anomalous aortic origin of coronary artery(AAOCA)and the causes of missed diagnosis by transthoracic echocardiography(TTE)so as to facilitate TTE in diagnosing adult AAOCA.Methods A total of 37 adult patients with AAOCA diagnosed by non-invasive coronary CT angiography(CCTA)and/or invasive coronary angiography(ICA)were selected as research samples at some hospital from January 2019 to December 2022,and their clinical symptoms and the findings of 12-lead electrocardiogram,cardiac enzymes and TTE were summarized;the patients were typed according to the site of origin of coronary artery anomalies,and the causes for the missed diagnosis of TTE were eplored.Chi-square test was used to compare the differences in TTE missed diagnoses.Results Of the 37 patients,31 ones had no or only mild symptoms;most ones had negative results in terms of 12-lead electrocardiography,cardiac enzymes,changes in the size of the cardiac chambers,segmental ventricular wall motion abnormalities and left ventricular systolic function.The patients with anomalous origin of the right coronary artery from left sinus(ARCA-L)gained the largest proportion of 59.45％(22/37);21 patients were diagnosed with anomalous origin of coronary artery arising from the opposite sinus(ACAOS)in the two examinations of TTE,of whom there were 19 cases of ARCA-L,and the detection rate of ACAOS by TTE was 87.5％;all the 13 patients origins in branches and high-grade openings were missed by TTE.The detection rate of ACAOS by TTE was significantly higher than that of coronary artery anomalies originating in branches and in high openings,and the difference was statistically significant(21/24 vs 0/13,P＜0.001).Conclusion Most adult AAOCA patients lack specificity in symptoms and related examination results.TTE has a high detection rate of ACAOS,while it is easy to miss the diagnosis of coronary artery anomalies originating from branches and high openings.Ultrasonographers have to identify false negative AAOCA by multi-section and multi-angle scanning and color Doppler flow imaging in order to reduce the rate of missed diagnosis.[Chinese Medical Equipment Journal,2024,45(1):71-75]

Objective To investigate the morphological typing and clinical significance of the distal tibiofibular syndesmosis fibular notch based on CT images. Methods According to the inclusion and exclusion ceiteria‚ the imaging data of patients undergoing ankle joint CT examination were analyzed‚ and the inferior tibiofibular joint fibula notch was classified according to the morphological characteristics. The measurements included 8 distances. There were 123 males and 102 females‚ all of whom were Han nationality‚ aged 18-60 years old. Results Retrospectively analyzed the result of 225 patients from December 2013 to December 2022. The distal tibiofibular syndesmosis fibular notch was divided into four types according to morphological characteristics‚ C-shaped (50. 67%)‚ V-shaped (26. 67%)‚ flat-shaped (15. 11%) and L-shaped (7. 56%). The angle between the anterior and posterior facets of the flat shape (145. 56 ± 9. 25)° was the largest and the angle between the anterior and posterior facets of the L shape (125. 07 ± 13. 54)° was the smallest(P< 0. 05); the depth of the notch in the flat shape (3. 11 ± 0. 83) mm was the smallest and in the L shape (4. 47±1. 11) mm was the largest(P<0. 05);The posterior facet length (13. 06 ± 3. 56) mm and anterior tibiofibular gap (3. 83±1. 49) mm on left were larger than on the right side (P<0. 05); The posterior facet length (13. 36 ± 3. 46) mm‚ fibular notch depth (3. 93 ± 1. 10) mm and vertical distance of tibiofibular overlap (9. 10 ± 2. 55) mm larger in men than in women (P<0. 05). Conclusion In this study‚ the data related to the inferior tibiofibular syndesmosis notch were measured and divided into four types according to the shape. The flat inferior tibiofibular syndesmosis notch is more likely to have chronic ankle instability‚ and the fibula is more likely to move forward during anatomical reduction. The inferior tibiofibular syndesmosis of L-shaped and C-shaped notches is more prone to posterior displacement of fibula or poor rotation reduction during anatomical reduction.

Objective To explore clinical effect of closed reduction percutaneous elastic intramedullary nail assisted by arthrography in the treatment of radial neck fracture in children.Methods A retrospective analysis was performed on 23 chil-dren with radial neck fracture treated with arthrography assisted closed reduction and percutaneous elastic intramedullary nail internal fixation(arthrography with elastic nail group)from January 2019 to December 2022,including 12 males and 11 fe-males,aged from 2 to 12 years old with an average of(7.36±1.89)years old;According to Judet fracture types,14 children were type Ⅲ and 9 children were type Ⅳ.In addition,23 children with radial neck fracture were selected from January 2015 to December 2018 who were treated with closed reduction and percutaneous elastic intramedullary nail fixation(elastic nail group),including 11 males and 12 females,aged from 2 to 14 years old with an average of(7.50±1.91)years old;Judet classi-fication included 15 children were type Ⅲ and 8 children were type Ⅳ.Operative time and intraoperative fluoroscopy times were compared between two groups.Metaizeau evaluation criteria was used to evaluate fracture reduction,and Tibone-Stoltz evaluation criteria was used to evaluate functional recovery of elbow between two groups.Results Both groups were followed up for 12 to 24 months with an average of(16.56±6.34)months.Operative time and intraoperative fluoroscopy times of elastic nail group were(56.64±19.27)min and(21.13±7.87)times,while those of joint angiography with elastic nail group were(40.33±1 1.50)min and(12.10±3.52)times;there were difference between two groups(P＜0.05).According to Metaizeau evaluation,11 patients got excellent result,9 good and 3 fair in joint angiography with elastic nail group,while in elastic nail group,5 ex-cellent,13 good,4 acceptable,and 1 poor;the difference between two groups was statistically significant(P＜0.05).According to Tibone-Stoltz criteria,14 patients got excellent result,8 good,and 1 fair in joint arthrography with elastic nail group;while in elastic nail group,12 patients got excellent result,9 good,1 fair and 1 poor;there was no significant difference between two groups(P＞0.05).Conclusion Compared to percutaneous elastic intramedullary nail fixation,closed reduction assisted by arthrography has advantages of reduced operation time,decreased intraoperative fluoroscopy frequency,and improved fracture reduction.Arthrography enables clear visualization of the anatomical structures of radius,head,neck,bone,and cartilage in children,facilitating comprehensive display of fracture reduction and brachioradial joint alignment.This technique more pre-cisely guides the depth of elastic intramedullary nail implantation in radius neck,thereby enhancing surgical efficiency and success rate.

This study was aimed at exploring the epidemiological characteristics of plague,and the evolutionary relation-ships among the isolated plague strains in the Yunnan border area,to provide clues for further studying epidemic causes and ep-idemiological patterns.Plague epidemic data in the border area during the second epidemic period(1982-2007)were collected and analyzed with descriptive epidemiological methods.Whole genome sequences of 262 strains of Yersinia pestis in the border area were obtained for phylogenetic analysis.Plague outbreaks occurred in 17 counties(cities)among 25 border counties(cit-ies);a total of 552 epidemic foci and 123 human cases were identified.The 1.ORI2,1.ORI3,1.IN3,2.ANT and 2.MED geno-types were identified among Yersinia pestis isolated from the Yunnan border area,among which the 1.ORI2 population was dominant.A total of 258 strains of Yersinia pestis from the 1.OR12 population belonged to four subclusters.The Myanmar and Vietnam clade was embedded within the Yunnan clade in the overall phylogeny.The above results indicated that during the sec-ond period of the epidemic,the intensity of plague epidemics in Yunnan's border areas was high,showing a trend of devel-opment from west to south and east.Our findings indicated a risk of cross-border transmission of plague between Yunnan and neighboring countries;therefore,the surveillance,pre-vention,and control of plague in border areas should be strengthened.

OBJECTIVE: To compare the clinical therapeutic effect between electroacupuncture at "four points of sacral region" and transurethral Erbium laser in treatment of moderate to severe stress urinary incontinence after radical prostatectomy. METHODS: A total of 68 patients of moderate to severe stress urinary incontinence after radical prostatectomy were divided into an electroacupuncture group (34 cases) and an Erbium laser group (34 cases, 3 cases dropped off) according to the settings. In the electroacupuncture group, electroacupuncture was applied at "four points of sacral region", i.e. points of 0.5 cun beside bilateral sacrococcygeal joints and bilateral Huiyang (BL 35), with continuous wave, 2 Hz in frequency, 60 min each time, once every other day, 3 times a week, 12 times as one course of treatment. In the Erbium laser group, transurethral Erbium laser technology was given, once every 4 weeks as one course of treatment. Both groups were treated for 5 courses. The scores of the International Consultation on Incontinence questionnaire-short form (ICI-Q-SF) and the incontinence quality of life questionnaire (I-QOL) were observed before treatment, after each course of treatment and in follow-up after 1 and 2 months of treatment completion, respectively, and the clinical efficacy was evaluated after treatment in the two groups. RESULTS: Compared with those before treatment, the ICI-Q-SF scores were decreased while the I-QOL scores were increased after 5 courses of treatment and in follow-up after 1, 2 months of treatment completion in the two groups (P<0.01). The ICI-Q-SF score in follow-up after 2 months of treatment completion were higher than that after 5 courses of treatment in the Erbium laser group (P<0.05). After 3, 4, 5 courses of treatment and in follow-up after 1 and 2 months of treatment completion, the ICI-Q-SF scores in the electroacupuncture group were lower than those in the Erbium laser group (P<0.05, P<0.01); after 2, 3, 4, 5 courses of treatment and in follow-up after 1 and 2 months of treatment completion, the I-QOL scores in the electroacupuncture group were higher than those in the Erbium laser group (P<0.01). The change ranges of ICI-Q-SF score and I-QOL score between before treatment and after each course of treatment in the electroacupuncture group were lager than those in the Erbium laser group (P<0.01, P<0.05). The total effective rate was 61.8% (21/34) in the electroacupuncture group, which was superior to 19.4 (6/31) in the Erbium laser group (P<0.01). CONCLUSION Both electroacupuncture at "four points of sacral region" and transurethral Erbium laser can improve the clinical symptoms and the quality of life in patients of moderate to severe stress urinary incontinence after radical prostatectomy. The short-term efficacy and long-term efficacy of electroacupuncture are superior to the Erbium laser technology.
Male ; Humans ; Quality of Life ; Urinary Incontinence, Stress/therapy* ; Sacrococcygeal Region ; Electroacupuncture ; Erbium ; Prostatectomy/adverse effects*

Objective: To explore the effects of three-dimensional (3D) bioprinting gelatin methacrylamide (GelMA) hydrogel loaded with nano silver on full-thickness skin defect wounds in rats. Methods: The experimental research method was adopted. The morphology, particle diameter, and distribution of silver nanoparticles in nano silver solution with different mass concentrations and the pore structure of silver-containing GelMA hydrogel with different final mass fractions of GelMA were observed by scanning electron microscope and the pore size was calculated. On treatment day 1, 3, 7, and 14, the concentration of nano silver released from the hydrogel containing GelMA with final mass fraction of 15% and nano silver with final mass concentration of 10 mg/L was detected by mass spectrometer. At 24 h of culture, the diameters of inhibition zone of GelMA hydrogel containing final mass concentration of 0 (no nano silver), 25, 50, and 100 mg/L nano silver against Staphylococcus aureus and Escherichia coli were detected. Fibroblasts (Fbs) and adipose stem cells (ASCs) were isolated respectively by enzymatic digestion using the discarded prepuce after circumcision from a 5-year-old healthy boy who was treated in the Department of Urology of the Second Affiliated Hospital of Zhejiang University School of Medicine in July 2020, and the discarded fat tissue after liposuction from a 23-year-old healthy woman who was treated in the Department of Plastic Surgery of the Hospital in July 2020. The Fbs were divided into blank control group (culture medium only), 2 mg/L nano sliver group, 5 mg/L nano sliver group, 10 mg/L nano sliver group, 25 mg/L nano sliver group, and 50 mg/L nano sliver group, which were added with the corresponding final mass concentrations of nano sliver solution, respectively. At 48 h of culture, the Fb proliferation viability was detected by cell counting kit 8 method. The Fbs were divided into 0 mg/L silver-containing GelMA hydrogel group, 10 mg/L silver-containing GelMA hydrogel group, 50 mg/L silver-containing GelMA hydrogel group, and 100 mg/L silver-containing GelMA hydrogel group and then were correspondingly treated. On culture day 1, 3, and 7, the Fb proliferation viability was detected as before. The ASCs were mixed into GelMA hydrogel and divided into 3D bioprinting group and non-printing group. On culture day 1, 3, and 7, the ASC proliferation viability was detected as before and cell growth was observed by live/dead cell fluorescence staining. The sample numbers in the above experiments were all 3. Four full-thickness skin defect wounds were produced on the back of 18 male Sprague-Dawley rats aged 4 to 6 weeks. The wounds were divided into hydrogel alone group, hydrogel/nano sliver group, hydrogel scaffold/nano sliver group, and hydrogel scaffold/nano sliver/ASC group, and transplanted with the corresponding scaffolds, respectively. On post injury day (PID) 4, 7, 14, and 21, the wound healing was observed and the wound healing rate was calculated (n=6). On PID 7 and 14, histopathological changes of wounds were observed by hematoxylin eosin staining (n=6). On PID 21, collagen deposition of wounds was observed by Masson staining (n=3). Data were statistically analyzed with one-way analysis of variance, analysis of variance for repeated measurement, Bonferroni correction, and independent sample t test. Results: The sliver nano particles in nano silver solution with different mass concentrations were all round, in scattered distribution and uniform in size. The silver-containing GelMA hydrogels with different final mass fractions of GelMA all showed pore structures of different sizes and interconnections. The pore size of silver-containing GelMA hydrogel with 10% final mass fraction was significantly larger than that of silver-containing GelMA hydrogels with 15% and 20% final mass fractions (with P values both below 0.05). On treatment day 1, 3, and 7, the concentration of nano silver released from silver-containing GelMA hydrogel in vitro showed a relatively flat trend. On treatment day 14, the concentration of released nano silver in vitro increased rapidly. At 24 h of culture, the diameters of inhibition zone of GelMA hydrogel containing 0, 25, 50, and 100 mg/L nano silver against Staphylococcus aureus and Escherichia coli were 0, 0, 0.7, and 2.1 mm and 0, 1.4, 3.2, and 3.3 mm, respectively. At 48 h of culture, the proliferation activity of Fbs in 2 mg/L nano silver group and 5 mg/L nano silver group was both significantly higher than that in blank control group (P<0.05), and the proliferation activity of Fbs in 10 mg/L nano silver group, 25 mg/L nano silver group, and 50 mg/L nano silver group was all significantly lower than that in blank control group (P<0.05). Compared with the that of Fbs in 0 mg/L silver-containing GelMA hydrogel group, the proliferation activity of Fbs in 50 mg/L silver-containing GelMA hydrogel group and 100 mg/L silver-containing GelMA hydrogel group was all significantly decreased on culture day 1 (P<0.05); the proliferation activity of Fbs in 50 mg/L silver-containing GelMA hydrogel group was significantly increased (P<0.05), while the proliferation activity of Fbs in 100 mg/L silver-containing GelMA hydrogel group was significantly decreased on culture day 3 (P<0.05); the proliferation activity of Fbs in 100 mg/L silver-containing GelMA hydrogel group was significantly decreased on culture day 7 (P<0.05). The proliferation activity of ASCs in 3D bioprinting group show no statistically significant differences to that in non-printing group on culture day 1 (P>0.05). The proliferation activity of ASCs in 3D bioprinting group was significantly higher than that in non-printing group on culture day 3 and 7 (with t values of 21.50 and 12.95, respectively, P<0.05). On culture day 1, the number of dead ASCs in 3D bioprinting group was slightly more than that in non-printing group. On culture day 3 and 5, the majority of ASCs in 3D bioprinting group and non-printing group were living cells. On PID 4, the wounds of rats in hydrogel alone group and hydrogel/nano sliver group had more exudation, and the wounds of rats in hydrogel scaffold/nano sliver group and hydrogel scaffold/nano sliver/ASC group were dry without obvious signs of infection. On PID 7, there was still a small amount of exudation on the wounds of rats in hydrogel alone group and hydrogel/nano sliver group, while the wounds of rats in hydrogel scaffold/nano sliver group and hydrogel scaffold/nano sliver/ASC group were dry and scabbed. On PID 14, the hydrogels on the wound surface of rats in the four groups all fell off. On PID 21, a small area of wounds remained unhealed in hydrogel alone group. On PID 4 and 7, the wound healing rates of rats in hydrogel scaffold/nano sliver/ASC group were significantly higher than those of the other three groups (P<0.05). On PID 14, the wound healing rate of rats in hydrogel scaffold/nano sliver/ASC group was significantly higher than the wound healing rates in hydrogel alone group and hydrogel/nano sliver group (all P<0.05). On PID 21, the wound healing rate of rats in hydrogel alone group was significantly lower than that in hydrogel scaffold/nano sliver/ASC group (P<0.05). On PID 7, the hydrogels on the wound surface of rats in the four groups remained in place; on PID 14, the hydrogel in hydrogel alone group was separated from the wounds of rats, while some hydrogels still existed in the new tissue of the wounds of rats in the other three groups. On PID 21, the collagen arrangement in the wounds of rats in hydrogel alone group was out of order, while the collagen arrangement in the wounds of rats in hydrogel/nano sliver group, and hydrogel scaffold/nano sliver/ASC group was relatively orderly. Conclusions: Silver-containing GelMA hydrogel has good biocompatibility and antibacterial properties. Its three-dimensional bioprinted double-layer structure can better integrate with new formed tissue in the full-thickness skin defect wounds in rats and promote wound healing.
Male ; Rats ; Animals ; Humans ; Hydrogels/pharmacology* ; Bioprinting ; Metal Nanoparticles ; Rats, Sprague-Dawley ; Silver/pharmacology* ; Soft Tissue Injuries ; Anti-Bacterial Agents