Objective: To investigate the effects of human umbilical cord mesenchymal stem cells (hUCMSCs) combined with autologous Meek microskin transplantation on patients with extensive burns. Methods: The prospective self-controlled study was conducted. From May 2019 to June 2022, 16 patients with extensive burns admitted to the 990^th Hospital of PLA Joint Logistics Support Force met the inclusion criteria, while 3 patients were excluded according to the exclusion criteria, and 13 patients were finally selected, including 10 males and 3 females, aged 24-61 (42±13) years. A total of 20 trial areas (40 wounds, with area of 10 cm×10 cm in each wound) were selected. Two adjacent wounds in each trial area were divided into hUCMSC+gel group applied with hyaluronic acid gel containing hUCMSCs and gel only group applied with hyaluronic acid gel only according to the random number table, with 20 wounds in each group. Afterwards the wounds in two groups were transplanted with autologous Meek microskin grafts with an extension ratio of 1∶6. In 2, 3, and 4 weeks post operation, the wound healing was observed, the wound healing rate was calculated, and the wound healing time was recorded. The specimen of wound secretion was collected for microorganism culture if there was purulent secretion on the wound post operation. In 3, 6, and 12 months post operation, the scar hyperplasia in wound was assessed using the Vancouver scar scale (VSS). In 3 months post operation, the wound tissue was collected for hematoxylin-eosin (HE) staining to observe the morphological changes and for immunohistochemical staining to observe the positive expressions of Ki67 and vimentin and to count the number of positive cells. Data were statistically analyzed with paired samples t test and Bonferronni correction. Results: In 2, 3, and 4 weeks post operation, the wound healing rates in hUCMSC+gel group were (80±11)%, (84±12)%, and (92±9)%, respectively, which were significantly higher than (67±18)%, (74±21)%, and (84±16)% in gel only group (with t values of 4.01, 3.52, and 3.66, respectively, P<0.05). The wound healing time in hUCMSC+gel group was (31±11) d, which was significantly shorter than (36±13) d in gel only group (t=-3.68, P<0.05). The microbiological culture of the postoperative wound secretion specimens from the adjacent wounds in 2 groups was identical, with negative results in 4 trial areas and positive results in 16 trial areas. In 3, 6, and 12 months post operation, the VSS scores of wounds in gel only group were 7.8±1.9, 6.7±2.1, and 5.4±1.6, which were significantly higher than 6.8±1.8, 5.6±1.6, and 4.0±1.4 in hUCMSC+gel group, respectively (with t values of -4.79, -4.37, and -5.47, respectively, P<0.05). In 3 months post operation, HE staining showed an increase in epidermal layer thickness and epidermal crest in wound in hUCMSC+gel group compared with those in gel only group, and immunohistochemical staining showed a significant increase in the number of Ki67 positive cells in wound in hUCMSC+gel group compared with those in gel only group (t=4.39, P<0.05), with no statistically significant difference in the number of vimentin positive cells in wound between the 2 groups (P>0.05). Conclusions: The application of hyaluronic acid gel containing hUCMSCs to the wound is simple to perform and is therefore a preferable route. Topical application of hUCMSCs can promote healing of the autologous Meek microskin grafted area in patients with extensive burns, shorten wound healing time, and alleviate scar hyperplasia. The above effects may be related to the increased epidermal thickness and epidermal crest, and active cell proliferation.
Female ; Humans ; Male ; Burns/surgery* ; Cicatrix ; Eosine Yellowish-(YS) ; Hyaluronic Acid/therapeutic use* ; Hyperplasia ; Ki-67 Antigen ; Prospective Studies ; Umbilical Cord ; Vimentin ; Young Adult ; Adult ; Middle Aged

BACKGROUND: Rapid on-site evaluation (ROSE) is a technique used for simultaneous evaluation of biopsy specimens through rapid cytology staining. Diff-Quik (DQ) staining is the most commonly employed method for cytological rapid on-site evaluation (C-ROSE). However, the utilization of DQ staining for on-site cytological interpretation remains uncommon among pathologists in China, posing challenges to the implementation of C-ROSE. This study aims to assess the application of rapid hematoxylin-eosin (HE) staining and DQ staining for C-ROSE during percutaneous needle biopsy of peripheral lung cancer and evaluate the value of rapid HE staining in C-ROSE. METHODS: Computed tomography (CT)-guided lung biopsies were conducted on 300 patients diagnosed with peripheral lung cancer. The patients were randomly assigned to two groups for C-ROSE using either rapid HE staining or DQ staining, and subsequently the two methods were compared and evaluated. RESULTS: The concordance rate between C-ROSE and histopathological diagnosis was 96.7%. The median staining time for rapid HE staining was 160 s, while that for DQ staining was 120 s, representing a significant difference between the two groups (P<0.001). However, there were no significant differences observed in terms of total biopsy time, concordance rate with histopathology, cytology specimen peeling rate, and incidence of serious adverse reactions between the two groups (P>0.05). CONCLUSIONS Both staining methods comply with C-ROSE criteria in the biopsy setting of peripheral lung cancer. Rapid HE staining is more aligned with domestic clinical requirements and holds potential for further promotion and adoption in C-ROSE.
Humans ; Lung Neoplasms/pathology* ; Eosine Yellowish-(YS) ; Rapid On-site Evaluation ; Biopsy, Needle/methods* ; Staining and Labeling

Eukaryotic translation initiation factor 4B (eIF4B) plays an important role in mRNA translation initiation, cell survival and proliferation in vitro, but the in vivo function is poorly understood. In this study, via various experimental techniques such as hematoxylin-eosin (HE) staining, flow cytometry, Western blotting, and immunohistochemistry, we investigated the role of eIF4B in mouse embryo development using an eIF4B knockout (KO) mouse model and explored the mechanism. We found that the livers, but not lungs, brain, stomach, or pancreas, derived from eIF4B KO mouse embryos displayed severe pathological changes characterized by enhanced apoptosis and necrosis. Accordingly, high expression of cleaved-caspase 3, and excessive activation of mTOR signaling as evidenced by increased expression and phosphorylation of p70S6K and enhanced phosphorylation of 4EBP1, were observed in mouse embryonic fibroblasts and fetal livers from eIF4B KO mice. These results uncover a critical role of eIF4B in mouse embryo development and provide important insights into the biological functions of eIF4B in vivo.
Animals ; Apoptosis/genetics* ; Caspase 3 ; Eosine Yellowish-(YS) ; Eukaryotic Initiation Factors/metabolism* ; Fibroblasts ; Hematoxylin ; Liver/metabolism* ; Mice ; Ribosomal Protein S6 Kinases, 70-kDa/genetics* ; TOR Serine-Threonine Kinases

To investigate the effect of Rehmanniae Radix on depression-like behavior and monoamine neurotransmitters of chronic unpredictable mild stress(CUMS) model rats. CUMS combined with isolated feeding was used to induce the depression model of rats. The depression-like behavior of rats was evaluated by sucrose preference test, open field test, and forced swim test. Hematoxylin-Eosin(HE) staining was used to investigate the pathological changes of neurons in the CA1 and CA3 area of hippocampus. Ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS) was used to detect the contents of 5-hydroxytryptamine(5-HT), 5-hydroxyindoleacetic acid(5-HIAA), dopamine(DA), 3,4-dihydroxyphenylacetic acid(DOPAC), homovanillic acid(HVA), norepinephrine(NE), and 3-methoxy-4-hydroxyphenyl glycol(MHPG) in rats. Western blot was used to detect the protein expressions of tryptophan hydroxylase 2(TPH2), serotonin transporter(SERT), and monoamine oxidase A(MAO-A) in the hippocampus of rats. Compared with the normal group, depressive-like behavior of rats was obvious in the model group. The arrangements of neurons in the CA1 and CA3 area of hippocampus were loose and disorderly. The levels of 5-HT, 5-HIAA, and 5-HT/5-HIAA in the hippocampal area were decreased(P<0.01). The protein expression of TPH2 was decreased(P<0.01), but those of SERT and MAO-A were increased(P<0.01). In the Rehmanniae Radix groups with 1.8 g·kg~(-1) and 7.2 g·kg~(-1), the depression-like behavior of CUMS rats and pathological changes of neurons in CA1, CA3 area of hippocampus were improved. The protein expression of TPH2(P<0.05, P<0.01) was increased, and those of SERT and MAO-A were down-regulated(P<0.05, P<0.01). The levels of 5-HT, 5-HIAA, and 5-HT/5-HIAA in hippocampus were increased(P<0.05, P<0.01). The changes in DA, DOPAC, HVA, DA/(DOPAC +HVA), NE, DHPG, and NE/DHPG were not statistically significant. The results suggested that Rehmanniae Radix improved depression-like behavior of CUMS rats, and the mechanism might be related to the regulation of synthesis, transportation, and metabolism of 5-HT neurotransmitter in the hippocampus.
3,4-Dihydroxyphenylacetic Acid/pharmacology* ; Animals ; Antidepressive Agents/therapeutic use* ; Chromatography, Liquid ; Depression/drug therapy* ; Disease Models, Animal ; Dopamine ; Eosine Yellowish-(YS)/pharmacology* ; Hematoxylin/pharmacology* ; Hippocampus/metabolism* ; Homovanillic Acid/pharmacology* ; Hydroxyindoleacetic Acid/metabolism* ; Methoxyhydroxyphenylglycol/pharmacology* ; Monoamine Oxidase/metabolism* ; Neurotransmitter Agents/metabolism* ; Norepinephrine/pharmacology* ; Plant Extracts ; Rats ; Rehmannia/chemistry* ; Serotonin/metabolism* ; Serotonin Plasma Membrane Transport Proteins/pharmacology* ; Stress, Psychological/metabolism* ; Tandem Mass Spectrometry ; Tryptophan Hydroxylase/metabolism*

This study aims to explore the effect of Jinzhen Oral Liquid(JOL) on cough after infection in rats and the mechanism. To be specific, a total of 60 male SD rats were classified into 6 groups: normal group(equivalent volume of distilled water, ig), model group(equivalent volume of distilled water, ig), Dextromethorphan Hydrobromide Oral Solution group(3.67 mL·kg~(-1), ig), high-, medium-, and low-dose JOL groups(11.34, 5.67, and 2.84 mL·kg~(-1), respectively, ig). Lipopolysaccharide(LPS, nasal drip), smoking, and capsaicin(nebulization) were employed to induce cough after infection in rats except the normal group. Administration began on the 19 th day and lasted 7 days. Capsaicin(nebulization) was used to stimulate cough 1 h after the last administration and the cough frequency and cough incubation period in rats were recorded. The pathological morphology of lung tissue was observed based on hematoxylin-eosin(HE) staining. Immunohistochemistry(IHC) was used to detect the specific expression of transient receptor potential vanilloid 1(Trpv1), nerve growth factor(NGF), tropomyosin receptor kinase A(TrkA), and phosphorylated-p38 mitogen-activated protein kinase(p-p38 MAPK) in lung tissue, Western blot the protein expression of Trpv1, NGF, TrkA, and p-p38 MAPK in lung tissue, and real-time fluorescent quantitative polymerase chain reaction(real-time PCR) the mRNA expression of Trpv1, NGF, and TrkA. The results showed that model group demonstrated significantly high cough frequency, obvious proliferation and inflammatory cell infiltration in lung tissue, significantly enhanced positive protein expression of Trpv1, NGF, TrkA, and p-p38 MAPK in lung tissue and significant increase in the mRNA expression of Trpv1, NGF, and TrkA compared with the normal group. Compared with the model group, JOL can significantly reduce the cough frequency, alleviate the pathological changes of lung tissue, and decrease the protein expression of Trpv1, NGF, TrkA, and p-p38 MAPK in lung tissue, and high-dose and medium-dose JOL can significantly lower the mRNA expression of Trpv1, NGF, and TrkA. This study revealed that JOL can effectively inhibit Trpv1 pathway-related proteins and improve cough after infection. The mechanism is that it reduces the expression of NGF, TrkA, and p-p38 MAPK in lung tissue, thereby decreasing the expression of Trpv1 and cough sensitivity.
Animals ; Capsaicin/adverse effects* ; Cough/drug therapy* ; Dextromethorphan/adverse effects* ; Eosine Yellowish-(YS)/adverse effects* ; Hematoxylin ; Lipopolysaccharides/adverse effects* ; Male ; Medicine, Chinese Traditional ; Nerve Growth Factor/metabolism* ; RNA, Messenger ; Rats ; Rats, Sprague-Dawley ; Receptor, trkA/metabolism* ; TRPV Cation Channels/metabolism* ; Tropomyosin/metabolism* ; Water/metabolism* ; p38 Mitogen-Activated Protein Kinases/metabolism*

This study aims to investigate mechanism of "Ephedrae Herba-Descurainiae Semen Lepidii Semen" combination(MT) in the treatment of bronchial asthma based on network pharmacology and in vivo experiment, which is expected to lay a theoretical basis for clinical application of the combination. First, the potential targets of MT in the treatment of bronchial asthma were predicted based on network pharmacology, and the "Chinese medicine-active component-target-pathway-disease" network was constructed, followed by Gene Oncology(GO) term enrichment and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment of the potential targets. Molecular docking was used to determine the binding activity of key candidate active components to hub genes. Ovalbumin(OVA, intraperitoneal injection for sensitization and nebulization for excitation) was used to induce bronchial asthma in rats. Rats were classified into control group(CON), model group(M), dexamethasone group(DEX, 0.075 mg·kg~(-1)), and MT(1∶1.5) group. Hematoxylin and eosin(HE), Masson, and periodic acid-Schiff(PAS) staining were performed to observe the effect of MT on pathological changes of lungs and trachea and goblet cell proliferation in asthma rats. The levels of transforming growth factor(TGF)-β1, interleukin(IL)6, and IL10 in rat serum were detected by enzyme-linked immunosorbent assay(ELISA), and the mRNA and protein levels of mitogen-activated protein kinase 8(MAPK8), cyclin D1(CCND1), IL6, epidermal growth factor receptor(EGFR), phosphatidylinositol 3-kinase(PI3 K), and protein kinase B(Akt) by qRT-PCR and Western blot. Network pharmacology predicted that MAPK8, CCND1, IL6, and EGFR were the potential targets of MT in the treatment of asthma, which may be related to PI3 K/Akt signaling pathway. Quercetin and β-sitosterol in MT acted on a lot of targets related to asthma, and molecular docking results showed that quercetin and β-sitosterol had strong binding activity to MAPK, PI3 K, and Akt. In vivo experiment showed that MT could effectively alleviate the symptoms of OVA-induced asthma rats, improve the pathological changes of lung tissue, reduce the production of goblet cells, inhibit the inflammatory response of asthma rats, suppress the expression of MAPK8, CCND1, IL6, and EGFR, and regulate the PI3 K/Akt signaling pathway. Therefore, MT may relieve the symptoms and inhibit inflammation of asthma rats by regulating the PI3 K/Akt signaling pathway, and quercetin and β-sitosterol are the candidate active components.
Animals ; Asthma/drug therapy* ; Cyclin D1 ; Dexamethasone/adverse effects* ; Drug Combinations ; Drugs, Chinese Herbal/therapeutic use* ; Eosine Yellowish-(YS)/adverse effects* ; Ephedra ; ErbB Receptors ; Hematoxylin/therapeutic use* ; Interleukin-10 ; Interleukin-6 ; Mitogen-Activated Protein Kinase 8/therapeutic use* ; Molecular Docking Simulation ; Network Pharmacology ; Ovalbumin/adverse effects* ; Periodic Acid/adverse effects* ; Phosphatidylinositol 3-Kinases ; Proto-Oncogene Proteins c-akt/metabolism* ; Quercetin ; RNA, Messenger ; Rats

OBJECTIVE: To investigate the effect of curcumol on NOD-like receptor thermoprotein domain 3 (NLRP3) inflammasomes, and analyze the mechanism underlying curcumol against liver fibrosis. METHODS: Thirty Kunming mice were divided into a control group, a model group and a curcumol group according to a random number table, 10 mice in each group. Mice were intraperitoneally injected with 40% carbon tetrachloride (CCl₄:peanut oil, 2:3 preparation) at 5 mL/kg for 6 weeks, twice a week, for developing a liver fibrosis model. The mice in the control group were given the same amount of peanut oil twice a week for 6 weeks. The mice in the curcumol group were given curcumol (30 mL/kg) intragastrically, and the mice in the model and control groups were given the same amount of normal saline once a day for 6 weeks. Changes in liver structure were observed by hematoxylin and eosin (HE) and Masson staining. Liver function, liver fiber indices, and the expression of interleukin (IL)-10 and tumor necrosis factor-α (TNF-α) levels were determined by automatic biochemical analyzer and enzyme linked immunosorbent assay kit. Immunoblotting and reverse transcription-quantitative PCR (RT-qPCR) were performed to detect the expression of NLRP3 inflammasome-related molecules, TGF-β and collagen. RESULTS: HE and Masson staining results showed that the hepatocytes of the model group were arranged irregularly with pseudo-lobular structure and a large amount of collagen deposition. The mice in the curcumol group had a significant decrease in liver function and liver fibers indices compared with the model group (P<0.05); RT-qPCR and Western blotting results reveal that, in the curcumol group, the mRNA and protein expression levels of NLRP3, IL-1 β, Caspase 1 and gasdermin D decreased significantly compared with the model group (P<0.05); immunohistochemical results showed that in the curcumol group, the protein expression levels of NLRP3 and IL-1 β decreased significantly compared with the model group (P<0.05). CONCLUSION A potential anti-liver fibrosis mechanism of curcumol may be associated with the inhibition of NLRP3 inflammasomes and decreasing the downstream inflammatory response.
Animals ; Mice ; Inflammasomes/metabolism* ; Interleukin-1beta/metabolism* ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; NLR Proteins ; Caspase 1 ; Tumor Necrosis Factor-alpha ; Carbon Tetrachloride ; Hematoxylin ; Saline Solution ; Eosine Yellowish-(YS) ; Peanut Oil ; Liver Cirrhosis/drug therapy* ; RNA, Messenger/genetics* ; Collagen ; Transforming Growth Factor beta

Deep venous thrombosis (DVT) poses a major challenge to public health worldwide. Endothelial cell injury evokes inflammatory and oxidative responses that contribute to thrombus formation. Tea polyphenol (TP) in the form of epigallocatechin-3-gallate (EGCG) has anti-inflammatory and oxidative effect that may ameliorate DVT. However, the precise mechanism remains incompletely understood. The current study was designed to investigate the anti-DVT mechanism of EGCG in combination with warfarin (an oral anticoagulant). Rabbits were randomly divided into five groups. A DVT model of rats was established through ligation of the inferior vena cava (IVC) and left common iliac vein, and the animals were orally administered with EGCG, warfarin, or vehicle for seven days. In vitro studies included pretreatment of human umbilical vein endothelial cells (HUVECs) with different concentrations of EGCG for 2 h before exposure to hydrogen peroxide. Thrombus weight and length were examined. Histopathological changes were observed by hematoxylin-eosin staining. Blood samples were collected for detecting coagulation function, including thrombin and prothrombin times, activated partial thromboplastin time, and fibrinogen levels. Protein expression in thrombosed IVCs and HUVECs was evaluated by Western blot, immunohistochemical analysis, and/or immunofluorescence staining. RT-qPCR was used to determine the levels of AGTR-1 and VEGF mRNA in IVCs and HUVECs. The viability of HUVECs was examined by CCK-8 assay. Flow cytometry was performed to detect cell apoptosis and ROS generation was assessed by 2',7'-dichlorofluorescein diacetate reagent. In vitro and invivo studies showed that EGCG combined with warfarin significantly reduced thrombus weight and length, and apoptosis in HUVECs. Our findings indicated that the combination of EGCG and warfarin protects HUVECs from oxidative stress and prevents apoptosis. However, HIF-1α silencing weakened these effects, which indicated that HIF-1α may participate in DVT. Furthermore, HIF-1α silencing significantly up-regulated cell apoptosis and ROS generation, and enhanced VEGF expression and the activation of the PI3K/AKT and ERK1/2 signaling pathways. In conclusion, our results indicate that EGCG combined with warfarin modifies HIF-1α and VEGF to prevent DVT in rabbits through anti-inflammation via the PI3K/AKT and ERK1/2 signaling pathways.
Animals ; Anticoagulants/pharmacology* ; Catechin/analogs & derivatives* ; Eosine Yellowish-(YS)/pharmacology* ; Fibrinogen/pharmacology* ; Hematoxylin/pharmacology* ; Human Umbilical Vein Endothelial Cells ; Humans ; Hydrogen Peroxide/pharmacology* ; Hypoxia-Inducible Factor 1, alpha Subunit/metabolism* ; MAP Kinase Signaling System ; Phosphatidylinositol 3-Kinases/metabolism* ; Polyphenols/pharmacology* ; Proto-Oncogene Proteins c-akt/metabolism* ; RNA, Messenger ; Rabbits ; Rats ; Reactive Oxygen Species/metabolism* ; Signal Transduction ; Sincalide/pharmacology* ; Tea ; Thrombin/pharmacology* ; Vascular Endothelial Growth Factor A/metabolism* ; Venous Thrombosis/pathology* ; Warfarin/pharmacology*

Objective: To explore the effect of P311 microspheres-loaded thermosensitive chitosan hydrogel on the wound healing of full-thickness skin defects in rats. Methods: The method of experimental study was adopted. The polyvinyl alcohol/sodium alginate microspheres (simple microspheres), P311 microspheres, and bovine serum albumin labeled with fluorescein isothiocyanate (FITC-BSA) microspheres were prepared by water-in-oil emulsification, and then their morphology was observed under a light microscope/inverted fluorescence microscope. Chitosan solution was prepared, chitosan solution and β-glycerol phosphate disodium hydrate were mixed to prepare simple thermosensitive hydrogels, and thermosensitive hydrogels loaded with simple microspheres or P311 microspheres were prepared by adding corresponding substances in simple thermosensitive hydrogels. The morphological changes of the prepared four liquids in the state of tilt was observed at 37 ℃. After being freeze-dried, the micromorphology of the prepared four liquids was observed under a scanning electron microscope. Eighteen 3-4-week-old male Sprague-Dawley rats were divided into normal group without any treatment, dressing group, chitosan group, hydrogel alone group, simple microspheres-loaded hydrogel group, and P311 microspheres-loaded hydrogel group, which were inflicted with one full-thickness skin defect wound on both sides of the back spine and were dealt correspondingly, with 3 rats in each group. Rats with full-thickness skin defects in the five groups were collected, the wound healing was observed on post injury day (PID) 0 (immediately), 5, 10, and 15, and the wound healing rates on PID 5, 10, and 15 were calculated. The wound and wound margin tissue of rats with full-thickness skin defects in the five groups on PID 15 and normal skin tissue in the same site of rats in normal group were collected, hematoxylin and eosin staining was conducted to observe the histological changes, immunohistochemical staining was performed to observe the expressions of CD31 and vascular endothelial growth factor (VEGF), and Western blotting was conducted to detect the protein expressions of CD31 and VEGF. The number of samples was all three. Data were statistically analyzed with one-way analysis of variance, analysis of variance for repeated measurement, and Bonferroni correction. Results: Simple microspheres were spherical, with loose and porous surface. The surfaces of P311 microspheres and FITC-BSA microspheres were smooth without pores, and the FITC-BSA microspheres emitted uniform green fluorescence. The diameters of the three microspheres were basically consistent, being 33.1 to 37.7 μm. Compared with chitosan solution and simple thermosensitive hydrogel, the structures of the two microspheres-loaded hydrogels were more stable in the state of tilt at 37 ℃. The two microspheres-loaded hydrogels had denser network structures than those of chitosan solution and simple thermosensitive hydrogel, and in the cross section of which microspheres with a diameter of about 30 μm could be seen. Within PID 15, the wounds of rats in the five groups were healed to different degrees, and the wound healing of rats in P311 microspheres-loaded hydrogel group was the best. On PID 5, 10, and 15, the wound healing rates of rats in dressing group and chitosan group were (26.6±2.4)%, (38.5±3.1)%, (50.9±1.5)%, (47.6±2.0)%, (58.5±3.6)%, and (66.7±4.1)%, respectively, which were significantly lower than (59.3±4.8)%, (87.6±3.2)%, (97.2±1.0)% in P311 microspheres-loaded hydrogel group (P<0.05 or P<0.01). The wound healing rates of rats in hydrogel alone group on PID 10 and 15, and in simple microspheres-loaded hydrogel group on PID 15 were (76.0±3.3)%, (84.5±3.6)%, and (88.0±2.6)%, respectively, which were significantly lower than those in P311 microspheres-loaded hydrogel group (P<0.05). The epidermis, hair follicles, and sebaceous glands could be seen in the normal skin of rats in normal group, without positive expressions of CD31 or VEGF. The wounds of rats in P311 microspheres-loaded hydrogel group on PID 15 were almost completely epithelialized, with more blood vessels, hair follicles, sebaceous glands, and positive expressions of CD31 and VEGF in the wounds than those of rats with full-thickness skin defects in the other four groups, and more protein expressions of CD31 and VEGF than those of rats in the other five groups. Conclusions: The P311 microspheres-loaded thermosensitive chitosan hydrogel can release the encapsulated drug slowly, prolong the drug action time, and promote wound healing in rats with full-thickness skin defects by promoting wound angiogenesis and re-epithelialization.
Rats ; Male ; Animals ; Hydrogels ; Vascular Endothelial Growth Factor A ; Chitosan/pharmacology* ; Serum Albumin, Bovine/pharmacology* ; Microspheres ; Polyvinyl Alcohol/pharmacology* ; Hematoxylin/pharmacology* ; Eosine Yellowish-(YS)/pharmacology* ; Rats, Sprague-Dawley ; Wound Healing ; Skin/injuries* ; Skin Abnormalities ; Soft Tissue Injuries ; Water/pharmacology* ; Alginates/pharmacology*

Objective: To explore the effects and mechanism of water-soluble chitosan hydrogel on infected full-thickness skin defect wounds in diabetic mice. Methods: The experimental research method was adopted. The control hydrogel composed of polyvinyl alcohol and gelatin, and the water-soluble chitosan hydrogel composed of the aforementioned two materials and water-soluble chitosan were prepared by the cyclic freeze-thaw method. The fluidity of the two dressings in test tube before and after the first freeze-thawing was generally observed, and the difference in appearance of the final state of two dressings in 12-well plates were compared. According to random number table (the same grouping method below), the cell strains of L929 and HaCaT were both divided into water-soluble chitosan hydrogel group and control hydrogel group, respectively. After adding corresponding dressings and culturing for 24 h, the cell proliferation activity was measured using cell counting kit 8. Rabbit blood erythrocyte suspensions were divided into normal saline group, polyethylene glycol octyl phenyl ether (Triton X-100) group, water-soluble chitosan hydrogel group, and control hydrogel group, which were treated accordingly and incubated for 1 hour, and then the hemolysis degree of erythrocyte was detected by a microplate reader. Twenty-four female db/db mice aged 11-14 weeks were selected, and full-thickness skin defect wounds on their backs were inflicted and inoculated with the methicillin-resistant Staphylococcus aureus (MRSA), 72 h later, the mice were divided into blank control group, sulfadiazine silver hydrogel group, control hydrogel group, and water-soluble chitosan hydrogel group, which were treated accordingly. On post injury day (PID) 0 (immediately), 7, 14, and 21, the healing of the wound was observed. On PID 14 and 21, the wound healing rate was calculated. On PID 14, MRSA concentration in wounds was determined. On PID 21, the wounds were histologically analyzed by hematoxylin and eosin staining; the expression of CD31 in the wounds was detected by immunofluorescence method, and its positive percentage was calculated. Raw264.7 cells were taken and divided into interleukin-4 (IL-4) group, blank control group, control hydrogel group, and water-soluble chitosan hydrogel group, which were treated accordingly. At 48 h of culture, the percentages of CD206 positive cells were detected by flow cytometry. The number of samples was all 3. Data were statistically analyzed with independent sample t test, one-way analysis of variance, analysis of variance for repeated measurement, least significant difference test, and Dunnett T3 test. Results: Two dressings in test tube had certain fluidity before freeze-thawing and formed semi-solid gels after freeze-thawing for once. The final forms of two dressings in 12-well plates were basically stable and translucent sheets, with little difference in transparency. At 24 h of culture, the cell proliferation activities of L929 and HaCaT in water-soluble chitosan hydrogel group were significantly higher than those in control hydrogel group (with t values of 6.37 and 7.50, respectively, P<0.01). At 1 h of incubation, the hemolysis degree of erythrocyte in water-soluble chitosan hydrogel group was significantly lower than that in Triton X-100 group (P<0.01), but similar to that in normal saline group and control hydrogel group (P>0.05). On PID 0, the traumatic conditions of mice in the 4 groups were similar. On PID 7, more yellowish exudates were observed inside the wound in blank control group and control hydrogel group, while a small amount of exudates were observed in the wound in sulfadiazine silver hydrogel group and water-soluble chitosan hydrogel group. On PID 14, the wounds in blank control group and control hydrogel group were dry and crusted without obvious epithelial coverage; in sulfadiazine silver hydrogel group, the scabs fell off and purulent exudate was visible on the wound; in water-soluble chitosan hydrogel group, the base of wound was light red and obvious epithelial coverage could be observed on the wound. On PID 14, the wound healing rate in water-soluble chitosan hydrogel group was significantly higher than that in the other 3 groups (all P<0.01). On PID 21, the wound in water-soluble chitosan hydrogel group was completely closed, while the wounds in the other 3 groups were not completely healed; the wound healing rate in water-soluble chitosan hydrogel group was significantly higher than that in the other 3 groups (all P<0.01). On PID 14, the concentration of MRSA in the wound in water-soluble chitosan hydrogel group was significantly lower than that in blank control group (P<0.01), but similar to that in control hydrogel group and sulfadiazine silver hydrogel group (P>0.05). On PID 21, the new epidermis was severely damaged in blank control group; the epidermis on the wound in control hydrogel group also had a large area of defect; complete new epidermis had not yet being formed on the wound in sulfadiazine silver hydrogel group; the wound in water-soluble chitosan hydrogel group was not only completely covered by the new epidermis, the basal cells of the new epidermis were also regularly aligned. On PID 21, the percentage of CD31 positivity in the wound in water-soluble chitosan hydrogel group was (2.19±0.35)%, which was significantly higher than (0.18±0.05)% in blank control group, (0.23±0.06)% in control hydrogel group, and (0.62±0.25)% in sulfadiazine silver hydrogel group, all P<0.01. At 48 h of culture, the percentage of CD206 positive Raw264.7 cells in water-soluble chitosan hydrogel group was lower than that in IL-4 group (P>0.01) but significantly higher than that in blank control group and control hydrogel group (P<0.05 or P<0.01). Conclusions: The water-soluble chitosan hydrogel has good biosafety and can induce higher level of macrophage M2 polarization than control hydrogel without water-soluble chitosan, so it can enhance the repair effect of MRSA-infected full-thickness skin defect wounds in diabetic mice and promote rapid wound healing.
Mice ; Female ; Animals ; Rabbits ; Interleukin-4 ; Hydrogels/pharmacology* ; Wound Healing ; Chitosan/pharmacology* ; Diabetes Mellitus, Experimental ; Water ; Methicillin-Resistant Staphylococcus aureus ; Gelatin ; Polyvinyl Alcohol ; Hemolysis ; Saline Solution ; Eosine Yellowish-(YS) ; Hematoxylin ; Octoxynol ; Silver ; Phenyl Ethers ; Sulfadiazine