1.Research progress on drug resistance mechanism of sorafenib in radioiodine refractory differentiated thyroid cancer
En-Tao ZHANG ; Hao-Nan ZHU ; Zheng-Ze WEN ; Cen-Hui ZHANG ; Yi-Huan ZHAO ; Ying-Jie MAO ; Jun-Pu WU ; Yu-Cheng JIN ; Xin JIN
The Chinese Journal of Clinical Pharmacology 2024;40(13):1986-1990
Most patients with differentiated thyroid cancer have a good prognosis after radioiodine-131 therapy,but a small number of patients are insensitive to radioiodine-131 therapy and even continue to develop disease.At present,some targeted drugs can improve progression-free survival in patients with radioactive iodine-refractory differentiated thyroid cancer(RAIR-DTC),such as sorafenib and levatinib,have been approved for the treatment of RAIR-DTC.However,due to the presence of primary and acquired drug resistance,drug efficacy in these patients is unsatisfactory.This review introduces the acquired drug resistance mechanism of sorafenib in the regulation of mitogen-activated protein kinase(MAPK)and phosphatidylinositol-3-kinase(PI3K)pathways and proposes related treatment strategies,in order to provide a reference for similar drug resistance mechanism of sorafenib and effective treatment of RAIR-DTC.
2.An optimal medicinal and edible Chinese herbal formula attenuates particulate matter-induced lung injury through its anti-oxidative, anti-inflammatory and anti-apoptosis activities.
Huan ZHANG ; Jun KANG ; Wuyan GUO ; Fujie WANG ; Mengjiao GUO ; Shanshan FENG ; Wuai ZHOU ; Jinnan LI ; Ayesha T TAHIR ; Shaoshan WANG ; Xinjun DU ; Hui ZHAO ; Weihua WANG ; Hong ZHU ; Bo ZHANG
Chinese Herbal Medicines 2023;15(3):407-420
OBJECTIVE:
Identifying novel strategies to prevent particulate matter (PM)-induced lung injury is crucial for the reduction of the morbidity of chronic respiratory diseases. The combined intervention represented by herbal formulae for simultaneously targeting multiple pathological processes can provide a more beneficial effect than the single intervention. The aim of this paper is therefore to design a safe and effective medicinal and edible Chinese herbs (MECHs) formula against PM-induced lung injury.
METHODS:
PM-induced oxidative stress, inflammatory response and apoptosis A549 cell model were used to screen anti-oxidant, anti-inflammatory and anti-apoptotic MECHs, respectively. A network pharmacology method was utilized to rationally design a novel herbal formula. Ultra performance liquid chromatography-mass spectrometer was utilized to assess the quality control of MECHs formula. The excretion of magnetic iron oxide nanospheres of the MECHs formula was estimated in zebrafish. The MECH formula against PM-induced lung injury was investigated with mice experiments.
RESULTS:
Five selected herbs were rationally designed to form a new MECH formula, including Citri Exocarpium Rubrum (Juhong), Lablab Semen Album (Baibiandou), Atractylodis Macrocephalae Rhizoma (Baizhu), Mori Folium (Sangye) and Polygonati Odorati Rhizoma (Yuzhu). The formula effectively promoted the magnetic iron oxide nanospheres excretion in zebrafish. The mid/high dose formula significantly prevented PM-induced lung damage in mice by enhancing the activity of SOD and GSH-Px, reducing the MDA and ROS level and attenuating the upregulation of pro-inflammatory cytokine (IL-6, IL-8, IL-1β and TNF-α), down regulating the protein expression of NF-κB, STAT3 and Caspase-3.
CONCLUSION
Our findings suggest that the effective MECHs formula will become a novel strategy for preventing PM-induced lung injury and provide a paradigm for the development of functional foods using MECHs.
3.Safety and efficacy of the early administration of levosimendan in patients with acute non-ST-segment elevation myocardial infarction and elevated NT-proBNP levels: An Early Management Strategy of Acute Heart Failure (EMS-AHF).
Feng XU ; Yuan BIAN ; Guo Qiang ZHANG ; Lu Yao GAO ; Yu Fa LIU ; Tong Xiang LIU ; Gang LI ; Rui Xue SONG ; Li Jun SU ; Yan Ju ZHOU ; Jia Yu CUI ; Xian Liang YAN ; Fang Ming GUO ; Huan Yi ZHANG ; Qing Hui LI ; Min ZHAO ; Li Kun MA ; Bei An YOU ; Ge WANG ; Li KONG ; Jian Liang MA ; Xin Fu ZHOU ; Ze Long CHANG ; Zhen Yu TANG ; Dan Yu YU ; Kai CHENG ; Li XUE ; Xiao LI ; Jiao Jiao PANG ; Jia Li WANG ; Hai Tao ZHANG ; Xue Zhong YU ; Yu Guo CHEN
Chinese Journal of Internal Medicine 2023;62(4):374-383
Objectives: To investigated the safety and efficacy of treating patients with acute non-ST-segment elevation myocardial infarction (NSTEMI) and elevated levels of N-terminal pro-hormone B-type natriuretic peptide (NT-proBNP) with levosimendan within 24 hours of first medical contact (FMC). Methods: This multicenter, open-label, block-randomized controlled trial (NCT03189901) investigated the safety and efficacy of levosimendan as an early management strategy of acute heart failure (EMS-AHF) for patients with NSTEMI and high NT-proBNP levels. This study included 255 patients with NSTEMI and elevated NT-proBNP levels, including 142 males and 113 females with a median age of 65 (58-70) years, and were admitted in the emergency or outpatient departments at 14 medical centers in China between October 2017 and October 2021. The patients were randomly divided into a levosimendan group (n=129) and a control group (n=126). The primary outcome measure was NT-proBNP levels on day 3 of treatment and changes in the NT-proBNP levels from baseline on day 5 after randomization. The secondary outcome measures included the proportion of patients with more than 30% reduction in NT-proBNP levels from baseline, major adverse cardiovascular events (MACE) during hospitalization and at 6 months after hospitalization, safety during the treatment, and health economics indices. The measurement data parameters between groups were compared using the t-test or the non-parametric test. The count data parameters were compared between groups using the χ² test. Results: On day 3, the NT-proBNP levels in the levosimendan group were lower than the control group but were statistically insignificant [866 (455, 1 960) vs. 1 118 (459, 2 417) ng/L, Z=-1.25,P=0.21]. However, on day 5, changes in the NT-proBNP levels from baseline in the levosimendan group were significantly higher than the control group [67.6% (33.8%,82.5%)vs.54.8% (7.3%,77.9%), Z=-2.14, P=0.03]. There were no significant differences in the proportion of patients with more than 30% reduction in the NT-proBNP levels on day 5 between the levosimendan and the control groups [77.5% (100/129) vs. 69.0% (87/126), χ²=2.34, P=0.13]. Furthermore, incidences of MACE did not show any significant differences between the two groups during hospitalization [4.7% (6/129) vs. 7.1% (9/126), χ²=0.72, P=0.40] and at 6 months [14.7% (19/129) vs. 12.7% (16/126), χ²=0.22, P=0.64]. Four cardiac deaths were reported in the control group during hospitalization [0 (0/129) vs. 3.2% (4/126), P=0.06]. However, 6-month survival rates were comparable between the two groups (log-rank test, P=0.18). Moreover, adverse events or serious adverse events such as shock, ventricular fibrillation, and ventricular tachycardia were not reported in both the groups during levosimendan treatment (days 0-1). The total cost of hospitalization [34 591.00(15 527.46,59 324.80) vs. 37 144.65(16 066.90,63 919.00)yuan, Z=-0.26, P=0.80] and the total length of hospitalization [9 (8, 12) vs. 10 (7, 13) days, Z=0.72, P=0.72] were lower for patients in the levosimendan group compared to those in the control group, but did not show statistically significant differences. Conclusions: Early administration of levosimendan reduced NT-proBNP levels in NSTEMI patients with elevated NT-proBNP and did not increase the total cost and length of hospitalization, but did not significantly improve MACE during hospitalization or at 6 months.
Male
;
Female
;
Humans
;
Aged
;
Natriuretic Peptide, Brain
;
Simendan/therapeutic use*
;
Non-ST Elevated Myocardial Infarction
;
Heart Failure/drug therapy*
;
Peptide Fragments
;
Arrhythmias, Cardiac
;
Biomarkers
;
Prognosis
4.Peripheral BDNF Regulates Somatosensory-Sympathetic Coupling in Brachial Plexus Avulsion-Induced Neuropathic Pain.
Hang XIAN ; Huan GUO ; Yuan-Ying LIU ; Jian-Lei ZHANG ; Wen-Chao HU ; Ming-Jun YU ; Rui ZHAO ; Rou-Gang XIE ; Hang ZHANG ; Rui CONG
Neuroscience Bulletin 2023;39(12):1789-1806
Brachial plexus avulsion (BPA) is a combined injury involving the central and peripheral nervous systems. Patients with BPA often experience severe neuropathic pain (NP) in the affected limb. NP is insensitive to the existing treatments, which makes it a challenge to researchers and clinicians. Accumulated evidence shows that a BPA-induced pain state is often accompanied by sympathetic nervous dysfunction, which suggests that the excitation state of the sympathetic nervous system is correlated with the existence of NP. However, the mechanism of how somatosensory neural crosstalk with the sympathetic nerve at the peripheral level remains unclear. In this study, through using a novel BPA C7 root avulsion mouse model, we found that the expression of BDNF and its receptor TrκB in the DRGs of the BPA mice increased, and the markers of sympathetic nervous system activity including α1 and α2 adrenergic receptors (α1-AR and α2-AR) also increased after BPA. The phenomenon of superexcitation of the sympathetic nervous system, including hypothermia and edema of the affected extremity, was also observed in BPA mice by using CatWalk gait analysis, an infrared thermometer, and an edema evaluation. Genetic knockdown of BDNF in DRGs not only reversed the mechanical allodynia but also alleviated the hypothermia and edema of the affected extremity in BPA mice. Further, intraperitoneal injection of adrenergic receptor inhibitors decreased neuronal excitability in patch clamp recording and reversed the mechanical allodynia of BPA mice. In another branch experiment, we also found the elevated expression of BDNF, TrκB, TH, α1-AR, and α2-AR in DRG tissues from BPA patients compared with normal human DRGs through western blot and immunohistochemistry. Our results revealed that peripheral BDNF is a key molecule in the regulation of somatosensory-sympathetic coupling in BPA-induced NP. This study also opens a novel analgesic target (BDNF) in the treatment of this pain with fewer complications, which has great potential for clinical transformation.
Humans
;
Mice
;
Animals
;
Hyperalgesia/metabolism*
;
Brain-Derived Neurotrophic Factor/metabolism*
;
Hypothermia/metabolism*
;
Neuralgia
;
Brachial Plexus/injuries*
;
Edema/metabolism*
5.To compare the efficacy and incidence of severe hematological adverse events of flumatinib and imatinib in patients newly diagnosed with chronic phase chronic myeloid leukemia.
Xiao Shuai ZHANG ; Bing Cheng LIU ; Xin DU ; Yan Li ZHANG ; Na XU ; Xiao Li LIU ; Wei Ming LI ; Hai LIN ; Rong LIANG ; Chun Yan CHEN ; Jian HUANG ; Yun Fan YANG ; Huan Ling ZHU ; Ling PAN ; Xiao Dong WANG ; Gui Hui LI ; Zhuo Gang LIU ; Yan Qing ZHANG ; Zhen Fang LIU ; Jian Da HU ; Chun Shui LIU ; Fei LI ; Wei YANG ; Li MENG ; Yan Qiu HAN ; Li E LIN ; Zhen Yu ZHAO ; Chuan Qing TU ; Cai Feng ZHENG ; Yan Liang BAI ; Ze Ping ZHOU ; Su Ning CHEN ; Hui Ying QIU ; Li Jie YANG ; Xiu Li SUN ; Hui SUN ; Li ZHOU ; Ze Lin LIU ; Dan Yu WANG ; Jian Xin GUO ; Li Ping PANG ; Qing Shu ZENG ; Xiao Hui SUO ; Wei Hua ZHANG ; Yuan Jun ZHENG ; Qian JIANG
Chinese Journal of Hematology 2023;44(9):728-736
Objective: To analyze and compare therapy responses, outcomes, and incidence of severe hematologic adverse events of flumatinib and imatinib in patients newly diagnosed with chronic phase chronic myeloid leukemia (CML) . Methods: Data of patients with chronic phase CML diagnosed between January 2006 and November 2022 from 76 centers, aged ≥18 years, and received initial flumatinib or imatinib therapy within 6 months after diagnosis in China were retrospectively interrogated. Propensity score matching (PSM) analysis was performed to reduce the bias of the initial TKI selection, and the therapy responses and outcomes of patients receiving initial flumatinib or imatinib therapy were compared. Results: A total of 4 833 adult patients with CML receiving initial imatinib (n=4 380) or flumatinib (n=453) therapy were included in the study. In the imatinib cohort, the median follow-up time was 54 [interquartile range (IQR), 31-85] months, and the 7-year cumulative incidences of CCyR, MMR, MR(4), and MR(4.5) were 95.2%, 88.4%, 78.3%, and 63.0%, respectively. The 7-year FFS, PFS, and OS rates were 71.8%, 93.0%, and 96.9%, respectively. With the median follow-up of 18 (IQR, 13-25) months in the flumatinib cohort, the 2-year cumulative incidences of CCyR, MMR, MR(4), and MR(4.5) were 95.4%, 86.5%, 58.4%, and 46.6%, respectively. The 2-year FFS, PFS, and OS rates were 80.1%, 95.0%, and 99.5%, respectively. The PSM analysis indicated that patients receiving initial flumatinib therapy had significantly higher cumulative incidences of CCyR, MMR, MR(4), and MR(4.5) and higher probabilities of FFS than those receiving the initial imatinib therapy (all P<0.001), whereas the PFS (P=0.230) and OS (P=0.268) were comparable between the two cohorts. The incidence of severe hematologic adverse events (grade≥Ⅲ) was comparable in the two cohorts. Conclusion: Patients receiving initial flumatinib therapy had higher cumulative incidences of therapy responses and higher probability of FFS than those receiving initial imatinib therapy, whereas the incidence of severe hematologic adverse events was comparable between the two cohorts.
Adult
;
Humans
;
Adolescent
;
Imatinib Mesylate/adverse effects*
;
Incidence
;
Antineoplastic Agents/adverse effects*
;
Retrospective Studies
;
Pyrimidines/adverse effects*
;
Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy*
;
Treatment Outcome
;
Benzamides/adverse effects*
;
Leukemia, Myeloid, Chronic-Phase/drug therapy*
;
Aminopyridines/therapeutic use*
;
Protein Kinase Inhibitors/therapeutic use*
6.Organizing Pneumonia in A Patient Double-Positive for ANCA and Anti-GBM Antibodies: A Case Report.
Fang-Yuan WANG ; Xiang-Ning YUAN ; Dan-Ni SUN ; Gong XIAO ; Cheng-Huan HU ; Zhong-Hua LIAO ; Jian-Ping NING ; Hui XU ; Jun-Tao FENG ; Hong-Ling YIN ; Xiao-Zhao LI
Chinese Medical Sciences Journal 2023;38(1):66-69
Both anti-glomerular basement membrane (GBM) disease and the anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) are common causes of pulmonary-renal syndrome. Organizing pneumonia (OP), a special pattern of interstitial lung disease, is extremely rare either in AAV or anti-GBM disease. We report an old woman presented with OP on a background of co-presentation with both ANCA and anti-GBM antibodies.
Female
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Humans
;
Antibodies, Antineutrophil Cytoplasmic
;
Organizing Pneumonia
;
Autoantibodies
;
Glomerulonephritis
;
Anti-Glomerular Basement Membrane Disease
;
Pneumonia
;
Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis/complications*
7.Specific Mutations in APC, with Prognostic Implications in Metastatic Colorectal Cancer
Huan PENG ; Jun YING ; Jia ZANG ; Hao LU ; Xiaokai ZHAO ; Pengmin YANG ; Xintao WANG ; Jieyi LI ; Ziying GONG ; Daoyun ZHANG ; Zhiguo WANG
Cancer Research and Treatment 2023;55(4):1270-1280
Purpose:
Loss-of-function mutations in the adenomatous polyposis coli (APC) gene are common in metastatic colorectal cancer (mCRC). However, the characteristic of APC specific mutations in mCRC is poorly understood. Here, we explored the clinical and molecular characteristics of N-terminal and C-terminal side APC mutations in Chinese patients with mCRC.
Materials and Methods:
Hybrid capture-based next-generation sequencing was performed on tumor tissues from 275 mCRC pati-ents to detect mutations in 639 tumor-associated genes. The prognostic value and gene-pathway difference between APC specific mutations in mCRC patients were analyzed.
Results:
APC mutations were highly clustered, accounting for 73% of all mCRC patients, and most of them were truncating mutations. The tumor mutation burden of the N-terminal side APC mutations group (n=76) was significantly lower than that of the C-terminal side group (n=123) (p < 0.001), further confirmed by the public database. Survival analysis showed that mCRC patients with N-terminus side APC mutations had longer overall survival than C-terminus side. Tumor gene pathway analysis showed that gene mutations in the RTK/RAS, Wnt and transforming growth factor β signaling pathways of the C-terminal group were significantly higher than those of the N-terminal group (p < 0.05). Additionally, KRAS, AMER1, TGFBR2, and ARID1A driver mutations were more common in patients with C-terminal side APC mutations.
Conclusion
APC specific mutations have potential function as mCRC prognostic biomarkers. There are obvious differences in the gene mutation patterns between the C-terminus and N-terminus APC mutations group, which may have certain guiding significance for the subsequent precise treatment of mCRC.
8.Role and mechanism of protein kinase D in the replication of human coronavirus 229E
Hui-Juan HAN ; Huan LIU ; Zhi-Jun ZHAO
Chinese Journal of Zoonoses 2023;39(11):1044-1052
This study investigated the role of protein kinase D(PKD)in the replication of human coronavirus 229E(HCoV-229E)and its potential molecular mechanisms.Using MRC-5 cells as a model,we assessed the expression levels of PKD family genes and proteins through qPCR and western blotting.We knocked down Prkd3 with siRNA and inhibited PKD activity with CRT0066101 to examine the replication lev-els of HCoV-229E-infected cells.Cell viability was assessed with CCK8,viral titration was determined with the TCID50,and immunofluorescence staining was used to assess HCoV-229E expression and the structure of the trans-Golgi network(TGN).The level of phosphatidylinositol 4,5-bisphosphate(PI(4,5)P2)was measured to reflect phosphatidylinositol 4-kinaseⅢβ(PI4KⅢβ)activity.PI4KⅢβ activity was inhibited with a PI4KⅢβ inhibitor(BQR695)to observe changes in TGN struc-ture and HCoV-229E replication after cell infection.CRT0066101 was used to inhibit PKD activity in Vero-E6 cells,and HCoV-229E replication levels were examined post-infection.The expression levels of PKD family genes and proteins,including Prkd1,Prkd2 and Prkd3,significantly increased during HCoV-229E infection.Knockdown of PKD3 significantly inhibited HCoV-229E mRNA levels and titers with respect to those in the control group(t=8.999,P<0.001;t=6.920,P<0.001),whereas overexpression of PKD3 increased HCoV-229E mRNA levels and titers(t=6.630,P<0.001;t=5.794,P<0.001).CRT0066101 also significantly inhibited HCoV-229E mRNA levels and titers(t=6.931,P<0.001;t=4.055,P<0.01).Im-munofluorescence staining indicated that CRT0066101 inhibited TGN fission caused by HCoV-229E infection.Inhibition of PI4KⅢβ activity significantly decreased PI(4,5)P2 levels,and BQR695 rescued the elevated PI(4,5)P2 levels caused by PKD overexpression(t=6.671,P<0.01).BQR695 decreased TGN fission in HCoV-229E-infected cells,and HCoV-229E mRNA levels and titers(t=5.151,P<0.001;t=7.744,P<0.001).CRT0066101 inhibited HCoV-229E mRNA levels and titers in Vero-E6 cells(t=7.480,P<0.001;t=7.228,P<0.01).This study revealed that PKD regulates TGN fission through modu-latingPI4KⅢβ and is involved in HCoV-229E replication.PKD inhibitors and PI4KⅢβ inhibitors significantly decreased HCoV-229E replication,thus providing important insights for future research onthe treatment of coronavirus infections.
9.Genome-wide characterization of three imported strains of novel coronavirus Omicron BQ.1 in Jinan,2022
Sa BAI ; Bao-Hua LIU ; Rong-Jun YAN ; Hui ZHAO ; Lian-Bo SUN ; Tao ZHANG ; Huan-Mei HAN
Chinese Journal of Zoonoses 2023;39(11):1060-1064
This study was aimed at understanding the genome-wide characterization and variations for three imported novel coronavirus(SARS-CoV-2)strains from different sources in the same period in Jinan at the viral genome level,to provide a sci-entific basis for further improving the prevention and control of COVID-19 outbreaks at Jinan port.We selected nasal and pha-ryngeal swab samples from three cases of imported asymptomatic COVID-19infectionat Jinan port;performed second-genera-tion whole-genome sequencing;and analyzed the variant loci and homology withvarious bioinformatics software.The whole ge-nome sequence of SARS-CoV-2 was successfully obtained from three samples of asymptomatic infected cases,and had full lengths ranging from 29 835 bp to 29 844 bp.Pangolin typing results indicated that the genotypes of the three samples were O-micron BQ.1,BQ.1.1,and BQ.1.12.Compared with the original Wuhan strain,the three samples produced mutations at 77,80,and 78 base sites,respectively,involving 60-63 non-synonymous mutations,mainly in the S and ORF1ab genes.Omicron BQ.1 is an imported variant of the SARS-CoV-2 virus and was detected for the first time at Jinan port.From a molecular biolo-gy perspective,this study provides a theoretical basis for the source tracing and prevention and control of COVID-19 at theport.
10.Effects of methacrylic anhydride gelatin hydrogel loaded with silver and recombinant human basic fibroblast growth factor on deep partial-thickness burn wounds in rabbits.
Xing Jun CHEN ; Xing WU ; Huan Huan LIN ; Zhao Xing LIU ; Sha LIU
Chinese Journal of Burns 2022;38(7):640-649
Objective: To investigate the effects of methacrylic anhydride gelatin (GelMA) hydrogel loaded with silver and recombinant human basic fibroblast growth factor (rh-bFGF) on deep partial-thickness burn wounds in rabbits. Methods: The experimental research method was adopted. Low-concentration GelMA materials, medium-concentration GelMA materials and high-concentration GelMA materials containing different concentrations of methacrylic anhydride (MA) were prepared, after adding photoinitiator, low-concentration GelMA hydrogels, medium-concentration GelMA hydrogels, and high-concentration GelMA hydrogels were obtained, respectively. The nuclear magnetic resonance spectroscopy was performed to detect the hydrogen nuclear magnetic resonance spectra of the above-mentioned three concentrations of GelMA materials, and to calculate the degree of substitution according to the spectrum diagram. The three-dimensional microstructure and pore size of 3 types of above-mentioned GelMA hydrogels were detected by field emission scanning electron microscopy (FESEM), with 9 samples measured. According to the selected concentration of MA, ten kinds of solutions of GelMA with different concentration of silver (silver-containing GelMA) were synthesized, and the silver-containing GelMA solution of each concentration was divided into three parts, and then exposed to ultraviolet light lasting for 20, 25, and 35 s, respectively. After adding photoinitiator,the corresponding silver-containing GelMA hydrogels were obtained. The residual degradation rate of silver-containing GelMA hydrogel with different photocrosslinking times was detected by collagenase degradation method at degradation of 12, 24, 36, and 48 h; and the time required for complete degradation was detected, and the sample number was 5. The inhibition zone diameter of GelMA hydrogel under above screened photocrosslinking times containing 10 concentrations of silver against Staphylococcus aureus was measured to reflect its antibacterial ability, and the sample numbers were all 5. The silver-containing GelMA hydrogel with statistical significance compared with the antibacterial circle diameter of the silver-containing GelMA hydrogel containing the lowest concentration (no silver) was considered as having antibacterial activity. The three-dimensional microstructure and pore size of the silver-containing GelMA hydrogels with antibacterial activity and the lowest drug concentration selected were detected by FESEM, and the sample numbers were all 9. The freeze-dried alone GelMA hydrogel and the freeze-dried silver-containing GelMA hydrogel were soaked in phosphate buffer solution for 24 h, respectively, then the swelling rate of the two GelMA hydrogel were calculated and compared by weighing method, and the sample number was 5. GelMA hydrogel containing silver and rh-bFGF, namely compound hydrogel for short, was prepared according to the preliminary experiment and the above experimental results. The appearance of the composite hydrogel was observed in general, and its three-dimensional microstructure and pore size were detected by FESEM. The deep partial-thickness burn wound was made on the back of 30 rabbits (aged 4-6 months, female half and half). Meanwhile, with the rabbit head as the benchmark, the wounds on the left side of the spine were treated as composite hydrogel treatment group, and the wounds on the right side were treated as gauze control group, and which were treated accordingly. On post injury day (PID) 3, 7, 14, 21, and 28, the healing of wounds in the two groups was observed. On PID 7, 14, 21, and 28, the wound healing area was recorded and the healing rate was calculated, with a sample number of 30. Data were statistically analyzed with analysis of variance for repeated measurement, one-way analysis of variance, and independent sample t test. Results: The substitution degree among low-concentration GelMA materials, medium-concentration GelMA materials, and high-concentration GelMA materials was significantly different (F=1 628.00, P<0.01). The low-concentration GelMA hydrogel had a loose and irregular three-dimensional spatial network structure with a pore size of (60±17) μm; the medium-concentration GelMA hydrogel had a relatively uniform three-dimensional spatial network and pore size with a pore size of (45±13) μm; the high-concentration GelMA hydrogel had the dense and disordered three-dimensional spatial network with a pore size of (25±15) μm, the pore sizes of 3 types of GelMA hydrogels were significantly differences (F=12.20, P<0.01), and medium concentration of MA was selected for the concentration of subsequent materials. The degradability of silver-containing GelMA hydrogels with different concentrations of the same photocrosslinking time was basically same. The degradation residual rates of silver-containing GelMA hydrogels with 20, 25, and 35 s crosslinking time at 12 h were (74.2±1.7)%, (85.3±0.9)%, and (93.2±1.2)%, respectively; the residual rates of degradation at 24 h were (58.3±2.1)%, (65.2±1.8)%, and (81.4±2.6)%, respectively; the residual rates of degradation at 36 h were (22.4±1.9)%, (45.2±1.7)%, and (68.1±1.4)%, respectively; the residual rates of degradation at 48 h were (8.2±1.7)%, (32.4±1.3)%, and (54.3±2.2)%, respectively, and 20, 25, and 30 s photocrosslinking time required for complete degradation of silver-containing GelMA hydrogels were (50.2±2.4), (62.4±1.4), and (72.2±3.2) h, and the difference was statistically significant (F=182.40, P<0.01), 25 s were selected as the subsequent photocrosslinking time. The antibacterial diameters of 10 types of silver-containing GelMA hydrogels against Staphylococcus aureus from low to high concentrations were (2.6±0.4), (2.5±0.4), (3.2±0.4), (12.1±0.7), (14.8±0.7), (15.1±0.5), (16.2±0.6), (16.7±0.5), (16.7±0.4), and (16.7±0.6) mm, respectively, and which basically showed a concentration-dependent increasing trend, and the overall difference was statistically significant (F=428.70, P<0.01). Compared with the silver-containing GelMA hydrogel with the lowest concentration, the antibacterial circle diameters of other silver-containing GelMA hydrogels with antibacterial ability from low to high concentration were significantly increased (with t values of 26.35, 33.84, 43.65, 42.17, 49.24, 55.74, and 43.72, respectively, P<0.01). The silver-containing GelMA hydrogel with the antibacterial diameter of (12.1±0.7) mm had the lowest antibacterial activity against Staphylococcus aureus and the lowest drug loading concentration, and the concentration of silver was selected for the concentration of subsequent materials. The microscopic morphology of the silver-containing GelMA hydrogel containing silver element with a pore size of (45±13) μm had a regular and linear strip-like structure. After soaking for 24 h, the swelling ratio of silver-containing GelMA hydrogel was similar to that of alone GelMA hydrogel. The composite hydrogel was colorless, clear and transparent, and its three-dimensional microstructure was a regular and uniform grid, with a filament network structure inside, and the pore size of (40±21) μm. On PID 3, a large amount of necrotic tissue and exudate of rabbit wound in composite hydrogel group were observed, and scattered scabs, a small amount of necrotic tissue and exudate of rabbit wound in gauze control group were observed. On PID 7, the area of rabbit wound in composite hydrogel group was significantly reduced, and adhesion of rabbit wound and gauze in gauze control group was observed. On PID 14, In composite hydrogel group, the rabbit wound surface was ruddy, and the growth of granulation tissue was observed, and in gauze control group, the rabbit wound base was pale, and the blood supply was poor. On PID 21, the rabbit wounds in composite hydrogel group healed completely, and rabbit wound in gauze control group had healing trend. On PID 28, new hair could be seen on rabbit wound surface in composite hydrogel group; oval wound of rabbit in gauze control group still remained. On PID 7, 14, 21, and 28, the wound healing areas of rabbit in composite hydrogel group were significantly larger than those in gauze control group (with t values of 2.24, 4.43, 7.67, and 7.69, respectively, P<0.05 or P<0.01). Conclusions: The medium-concentration GelMA hydrogel has good physical and chemical properties in terms of swelling and degradability. The screened silver-containing GelMA hydrogels had the lowest antibacterial activity and the lowest drug loading concentration. Composite hydrogel can significantly shorten the healing time of deep partial-thickness burn wounds in rabbits.
Anhydrides
;
Animals
;
Anti-Bacterial Agents
;
Burns/drug therapy*
;
Female
;
Fibroblast Growth Factor 2
;
Gelatin/pharmacology*
;
Humans
;
Hydrogels/pharmacology*
;
Rabbits
;
Recombinant Proteins
;
Staphylococcal Infections
;
Staphylococcus aureus

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