: Steven Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN) are severe cutaneous adverse reactions (SCAR) differentiated by degree of skin detachment. Common triggers include anticonvulsants, sulfonamides, antibiotics (penicillin, cephalosporin, quinolones) and acetaminophen. Reports of clindamycin causing cutaneous complications are rare with only 6 published reports, none of which were reported in the Philippines. Though uncommon, it is an important consideration in patients presenting with erythematous to violaceous purpuric macules that progress to full thickness epidermal exfoliation. : A 59-year-old female who presented with erythematous maculopapular rash on both hands, dry crusted lesions on the mouth and positive Nikolsky sign within 28 days of administration of Clindamycin. Algorithm for assessment of drug causality in SJS and TENS (ALDEN) was done and Clindamycin scored 6 points, which points to a definite drug causality of SJS/TEN. : A female in her late 50s presented with fatigue, malaise, and sore throat. Initially managed as a case of sepsis peritonsillar abscess right but later in the course of admission, presented with erythematous maculopapular rash on both hands and dry crusted lesions on the mouth. Patient was clinically diagnosed with Steven-Johnson syndrome and toxic epidermal syndrome and was given a course of intravenous hydrocortisone. Patient unfortunately expired due to overwhelming sepsis. Severe cutaneous adverse reaction induced by clindamycin are rare but important life-threatening conditions which needs prompt recognition and treatment. SJS/TEN as a secondary diagnosis leads to a delay in management, therefore a high index of suspicion and the utility of validated scoring tools should be maintained throughout the course of treatment.
Clindamycin

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

Objective: To explore the clinical characteristics, common pathogens in children with vulvovaginitis. Methods: This was a retrospective cases study. A total of 3 268 children with vulvovaginitis were enrolled, who visited the Department of Pediatric and Adolescent Gynecology, Children's Hospital, Zhejiang University School of Medicine from January 2009 to December 2019. Patients were divided into 3 groups according to the age of <7, 7-<10 and 10-18 years. Patients were also divided in to 4 groups according to the season of first visit. The pathogen distribution characteristics of infective vulvovaginitis were compared between the groups. Their clinical data were collected and then analyzed by χ² test. Results: The were 3 268 girls aged (6.2±2.5) years. There were 1 728 cases (52.9%) aged <7 years, 875 cases (26.8%) aged 7-<10 years, and 665 cases (20.3%) aged 10-18 years. Of these cases, 2 253 cases (68.9%) were bacterial vulvovaginitis, 715 cases (21.9%) were fungal vulvovaginitis and 300 cases (9.2%) were vulvovaginitis infected with other pathogens. Bacterial culture of vaginal secretions was performed in 2 287 cases, and 2 287 strains (70.0%) of pathogens were detected, of which the top 5 pathogens were Streptococcus pyogenes (745 strains, 32.6%), Haemophilus influenzae (717 strains, 31.4%), Escherichia coli (292 strains, 12.8%), Staphylococcus aureus (222 strains, 9.7%) and Klebsiella pneumoniae (67 strains, 2.9%). Regarding different age groups, H.influenzae was the most common in children under 7 years of age (40.3%, 509/1 263), S.pyogenes (41.9%, 356/849) was predominantly in children aged 7 to 10 years, and E.coli was predominant in children aged 10 to 18 years (26.3%, 46/175). Susceptibility results showed that S.pyogenes was susceptible to penicillin G (610/610, 100.0%), ceftriaxone (525/525, 100.0%), and vancomycin (610/610, 100.0%); the resistance rates to erythromycin and clindamycin were 91.9% (501/545)and 90.7% (495/546), respectively. For H.influenzae, 32.5% (161/496) produced β-elactamase, and all strains were sensitive to meropenem (489/489, 100.0%) and levofloxacin (388/388, 100.0%), while 40.5% (202/499) were resistant to ampicillin. Among E.coli, all strains were sensitive to imipenem(100%, 175/175). The resistance rates of E.coli to levofloxacin and ceftriaxone were 29.1% (43/148) and 35.1% (59/168), respectively. A total of 48 strains of methicillin-resistant Staphylococcus aureus (MRSA) were isolated with a proportion of 28.3% (45/159) in 3 268 patients. The results of drug susceptibility test showed that all MRSA strains were sensitive to linezolid 100.0% (40/40), vancomycin (45/45, 100.0%), and tigecycline (36/36, 100.0%); the resistance rates of MRSA to penicillin G, erythromycin and clindamycin were 100% (45/45), 95.6% (43/45) and 88.9% (40/45), respectively. All methicillin-sensitive Staphylococcus aureus (MSSA) strains were sensitive to oxacillin (114/114, 100.0%), linezolid (94/94, 100.0%), vancomycin (114/114, 100.0%), and tigecycline (84/84, 100.0%); it's resistance rates to penicillin G, erythromycin and clindamycin were 78.1% (89/114), 59.7% (68/114) and 46.5% (53/114), respectively. The drug resistance rate of MSSA to penicillin G, erythromycin and clindamycin were lower than those of MRSA (χ²=11.71,19.74,23.95, respectively, all P<0.001). Conclusions: The age of consultation for pediatric infectious vulvovaginitis is mainly around 6 years. The most common pathogens are S.pyogenes, H.influenzae and Escherichia coli. Third generation cephalosporins can be used as the first choice of empirical anti-infection drugs. However, the results of drug susceptibility should be considered for targeted treatment.
Female ; Adolescent ; Child ; Humans ; Anti-Bacterial Agents/therapeutic use* ; Vancomycin/therapeutic use* ; Methicillin-Resistant Staphylococcus aureus ; Clindamycin/therapeutic use* ; Ceftriaxone/therapeutic use* ; Tigecycline/therapeutic use* ; Linezolid/therapeutic use* ; Levofloxacin/therapeutic use* ; Retrospective Studies ; Microbial Sensitivity Tests ; Staphylococcus aureus ; Staphylococcal Infections/drug therapy* ; Erythromycin/therapeutic use* ; Methicillin ; Penicillin G/therapeutic use* ; Escherichia coli ; Drug Resistance, Bacterial

OBJECTIVE: To investigate the effect of 300 mL carbohydrates intake two hours before sur-gery on the gastric volume (GV) in patients positioning in trendelenburg undergoing gynecological laparoscopic procedures by using gastric antrum sonography, and further assess the risk of reflux aspiration. METHODS: From June 2020 to February 2021, a total of 80 patients, aged 18-65 years, body mass index (BMI) 18-35 kg/m², falling into American Society of Anesthesiologists (ASA) physical status Ⅰ or Ⅱ, scheduled for gynecological laparoscopic procedures positioning in trendelenburg were recruited and divided into two groups: the observation group (n =40) and the control group (n=40). In the observation group, solid food was restricted after 24:00, the patients were required to take 300 mL carbohydrates two hours before surgery. In the control group, solid food and liquid intake were restricted after 24:00 the night before surgery. The cross-sectional area (CSA) of gastric antrum was measured in supine position and right lateral decubitus position before anesthesia. Primary outcome was gastric volume (GV) in each group. Secondary outcome included Perlas A semi-quantitative grading and gastric volume/weight (GV/W). All the patients received assessment of preoperative feeling of thirsty and hunger with visual analogue scale (VAS). RESULTS: Complete data were available in eighty patients. GV was (58.8±23.6) mL in the intervention group vs. (56.3±22.1) mL in the control group, GV/W was (0.97±0.39) mL/kg vs. (0.95±0.35) mL/kg, respectively; all the above showed no significant difference between the two groups (P > 0.05). Perlas A semi-quantitative grading showed 0 in 24 patients (60%), 1 in 15 patients (37.5%), 2 in 1 patient (2.5%) in the intervention group and 0 in 25 (62.5%), 1 in 13 (32.5%), 2 in 2 (5%) in the control group, the proportion of Perlas A semi-quantitative grading showed no significant difference between the two groups (P > 0.05). A total of 3 patients (1 in the intervention group and 2 in the control group) with Perlas A semi-quantitative grading 2 were treated with special intervention, no aspiration case was observed in this study. The observation group endured less thirst and hunger (P＜0.05). CONCLUSION Three hundred mL carbohydrates intake two hours before surgery along with ultrasound guided gastric content monitoring does not increase gastric volume and the risk of reflux aspiration in patients positioning in trendelenburg undergoing gynecological laparoscopic surgery, and is helpful in minimizing disturbance to the patient's physiological needs, therefore leading to better clinical outcome.
Female ; Humans ; Supine Position ; Prospective Studies ; Pyloric Antrum ; Laparoscopy/adverse effects* ; Carbohydrates

OBJECTIVE: To investigate the effect of gastric antrum ultrasonography in evaluating gastric emptying after oral administration of 300 mL carbohydrates two hours before cesarean section, and to analyze the risk factors of gastric emptying in pregnant women. METHODS: From August 2020 to February 2021, a total of 80 patients, aged 22-43 years, body mass index (BMI) < 35 kg/m², gestational age≥36 weeks, falling into American Society of Anesthesiologists (ASA) physical status Ⅰ or Ⅱ, scheduled for cesarean sections in Peking University International Hospital were recruited and divided into two groups: the intervention group (n=40)and the control group (n=40). In the intervention group, solid food was restricted after 22:00, the patients were required to take 300 mL carbohydrates two hours before cesarean section. In the control group, solid food and liquid intake were restricted after 22:00 the night before surgery. All the patients received assessment of preoperative feeling of thirst and starvation with visual analogue scale (VAS). The cross-sectional area (CSA)of gastric antrum was measured in supine position and right supine position before anesthesia, the gastric volume (GV)and the gastric volume/weight(GV/W)of the two groups was further calculated. Perlas A semi-quantitative grading assessments were performed in each patient. The blood pressure and heart rate were recorded at admission(T0), 5 minutes after anesthesia (T1), immediately after fetal delivery (T2) and at the end of the surgery (T3). The occurrence of nausea and vomiting during the operation and 24 hours after the operation were recorded. RESULTS: One case in each group was excluded because the antrum was not clearly identified during the ultrasound assessments. In the semi-sitting position, the CSA was (5.07±1.73) cm² in the intervention group vs. (5.24±1.96) cm² in the control group, respectively; in the right lateral decubitus position, CSA was (7.32±2.17) cm² in the intervention group vs. (7.25±2.24) cm² in the control group, GV was (91.74±32.34) mL vs. (90.07±31.68) mL, GV/W was (1.27±0.40) mL/kg vs. (1.22±0.41) mL/kg, respectively; all the above showed no significant difference between the two groups (P > 0.05). Perlas A semi-quantitative grading showed 0 in 20 patients (51.3%), 1 in 16 (41%), 2 in 3 (7.7%)in the intervention group and 0 in 22 (56.4%), 1 in 15 (38.5%), 2 in 2 (5.1%)in the control group, the proportion of Perlas A semi-quantitative grading showed no significant difference between the two groups (P > 0.05). For the patients with Perlas A semi-quantitative grade 2 (3 cases in the intervention group and 2 cases in the control group), metoclopramide 0.2 mg/kg was intravenously injected before anesthesia. No aspiration case was observed in this study. The intervention group was endured less thirst and hunger (P < 0.05). There was no significant difference in blood pressure and heart rate between the two groups at each time point (P > 0.05). There was no significant difference in the incidence of intraoperative hypotension between the two groups (P > 0.05). There was no significant difference in the incidence of nausea intraoperatively and postoperatively between the two groups (P > 0.05). CONCLUSION Ultrasonography of gastric antrum can provide objective basis for evaluating gastric emptying of pregnant women perioperatively. 300 mL carbohydrates intake two hours before surgery, which does not increase GV and the risk of reflux aspiration, and is helpful in minimizing disturbance to the patient's physiological status, therefore leading to better clinical outcome.
Humans ; Female ; Pregnancy ; Gastric Emptying/physiology* ; Cesarean Section ; Prospective Studies ; Ultrasonography ; Carbohydrates ; Nausea

OBJECTIVES: To design and prepare silk fibroin/hyaluronic acid composite hydrogel. METHODS: The thiol modified silk fibroin and the double-bond modified hyaluronic acid were rapidly cured into gels through thiol-ene click polymerization under ultraviolet light condition. The grafting rate of modified silk fibroin and hyaluronic acid was characterized by ¹H NMR spectroscopy; the gel point and the internal microstructure of hydrogels were characterized by rheological test and scanning electron microscopy; the mechanical properties were characterized by compression test; the swelling rate and degradation rate were determined by mass method. The hydrogel was co-cultured with the cells, the cytotoxicity was measured by the lactate dehydrogenase method, the cell adhesion was measured by the float count method, and the cell growth and differentiation on the surface of the gel were observed by scanning electron microscope and fluorescence microscope. RESULTS: The functional group substitution degrees of modified silk fibroin and hyaluronic acid were 17.99% and 48.03%, respectively. The prepared silk fibroin/hyaluronic acid composite hydrogel had a gel point of 40-60 s and had a porous structure inside the gel. The compressive strength was as high as 450 kPa and it would not break after ten cycles. The water absorption capacity of the composite hydrogel was 4-10 times of its own weight. Degradation experiments showed that the hydrogel was biodegradable, and the degradation rate reached 28%-42% after 35 d. The cell biology experiments showed that the cytotoxicity of the composite gel was low, the cell adhesion was good, and the growth and differentiation of the cells on the surface of the gel were good. CONCLUSIONS The photocurable silk fibroin/hyaluronic acid composite hydrogel can form a gel quickly, and has excellent mechanical properties, adjustable swelling rate and degradation degree, good biocompatibility, so it has promising application prospects in biomedicine.
Fibroins/chemistry* ; Hydrogels/chemistry* ; Hyaluronic Acid/chemistry* ; Biocompatible Materials/chemistry* ; Click Chemistry ; Sulfhydryl Compounds ; Silk/chemistry*

Soft tissue is an indispensable tissue in human body. It plays an important role in protecting the body from external physical, chemical or biological factors. Mild soft tissue injuries can self-heal, while severe soft tissue injuries may require related treatment. Natural polymers (such as chitosan, hyaluronic acid, and collagen) and synthetic polymers (such as polyethylene glycol and polylactic acid) exhibit good biocompatibility, biodegradability and low toxicity. It can be used for soft tissue repairs for antibacterial, hemostatic and wound healing purposes. Their related properties can be enhanced through modification or preparation of composite materials. Commonly used soft tissue repairs include wound dressings, biological patches, medical tissue adhesives, and tissue engineering scaffolds. This study introduces the properties, mechanisms of action and applications of various soft tissue repair medical materials, including chitosan, hyaluronic acid, collagen, polyethylene glycol and polylactic acid, and provides an outlook on the application prospects of soft tissue repair medical materials and products.
Humans ; Biocompatible Materials/chemistry* ; Chitosan/chemistry* ; Hyaluronic Acid ; Tissue Scaffolds/chemistry* ; Collagen/chemistry* ; Polymers/chemistry* ; Polyethylene Glycols ; Soft Tissue Injuries

Recently, returning straw to the fields has been proved as a direct and effective method to tackle soil nutrient loss and agricultural pollution. Meanwhile, the slow decomposition of straw may harm the growth of the next crop. This study aimed to determine the effects of rumen microorganisms (RMs) on straw decomposition, bacterial microbial community structure, soil properties, and soil enzyme activity. The results showed that RMs significantly enhanced the degradation rate of straw in the soil, reaching 39.52%, which was 41.37% higher than that of the control on the 30th day after straw return. After 30 d, straw degradation showed a significant slower trend in both the control and the experimental groups. According to the soil physicochemical parameters, the application of rumen fluid expedited soil matter transformation and nutrient buildup, and increased the urease, sucrase, and cellulase activity by 10%‒20%. The qualitative analysis of straw showed that the hydroxyl functional group structure of cellulose in straw was greatly damaged after the application of rumen fluid. The analysis of soil microbial community structure revealed that the addition of rumen fluid led to the proliferation of Actinobacteria with strong cellulose degradation ability, which was the main reason for the accelerated straw decomposition. Our study highlights that returning rice straw to the fields with rumen fluid inoculation can be used as an effective measure to enhance the biological value of recycled rice straw, proposing a viable solution to the problem of sluggish straw decomposition.
Animals ; Rumen/metabolism* ; Agriculture/methods* ; Soil/chemistry* ; Microbiota ; Bacteria/metabolism* ; Oryza/metabolism* ; Soil Microbiology ; Cellulose

Objective: To investigate the cytomorphological and immunocytochemical features of tumor cells in the ascites of ovarian plasmacytoma (SOC). Methods: Specimens of serous cavity effusions were collected from 61 tumor patients admitted to the Affiliated Wuxi People's Hospital of Nanjing Medical University from January 2015 to July 2021, including ascites from 32 SOC, 10 gastrointestinal adenocarcinomas, 5 pancreatic ductal adenocarcinomas, 6 lung adenocarcinomas, 4 benign mesothelial hyperplasia and 1 malignant mesothelioma patients, pleural effusions from 2 malignant mesothelioma patients and pericardial effusion from 1 malignant mesothelioma. Serous cavity effusion samples of all patients were collected, conventional smears were made through centrifugation, and cell paraffin blocks were made through centrifugation of remaining effusion samples. Conventional HE staining and immunocytochemical staining were applied to observe and summarize cytomorphological characteristics and immunocytochemical characteristics. The levels of serum tumor markers carbohydrate antigen 125 (CA125), carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) were detected. Results: Of the 32 SOC patients, 5 had low-grade serous ovarian carcinoma (LGSOC) and 27 had high-grade serous ovarian carcinoma (HGSOC). 29 (90.6%) SOC patients had elevated serum CA125, but the difference was not statistically significant between them and patients with non-ovarian primary lesions included in the study (P>0.05); The serum CEA was positive in 9 patients with gastrointestinal adenocarcinoma and 5 patients with lung adenocarcinoma, and the positive rate was higher than that in SOC patients (P<0.001); The serum CA19-9 was positive in 5 patients with gastrointestinal adenocarcinoma and 5 patients with pancreatic ductal adenocarcinoma, and the positive rate was higher than that in SOC patients (P<0.05). The serum CA125, CEA and CA19-9 were within the normal range in 4 patients with benign mesothelial hyperplasia. LGSOC tumor cells were less heterogeneous and aggregated into small clusters or papillary pattern, and psammoma bodies could be observed in some LGSOC cases. The background cells were fewer and lymphocytes were predominant; the papillary structure was more obvious after making cell wax blocks. HGSOC tumor cells were highly heterogeneous, with significantly enlarged nuclei and varying sizes, which could be more than 3-fold different, and nucleoli and nuclear schizophrenia could be observed in some cases; tumor cells were mostly clustered into nested clusters, papillae and prune shapes; there were more background cells, mainly histiocytes. Immunocytochemical staining showed that AE1/AE3, CK7, PAX-8, CA125, and WT1 were diffusely positively expressed in 32 SOC cases. P53 was focally positive in all 5 LGSOCs, diffusely positive in 23 HGSOCs, and negative in the other 4 HGSOCs. Most of adenocarcinomas of the gastrointestinal tract and lung had a history of surgery, and tumor cells of pancreatic ductal adenocarcinoma tend to form small cell nests. Immunocytochemistry can assist in the differential diagnosis of mesothelial-derived lesions with characteristic "open window" phenomenon. Conclusion: Combining the clinical manifestations of the patient, the morphological characteristics of the cells in the smear and cell block of the ascites can provide important clues for the diagnosis of SOC, and the immunocytochemical tests can further improve the accuracy of the diagnosis.
Female ; Humans ; Carcinoembryonic Antigen ; Ascites ; CA-19-9 Antigen ; Mesothelioma, Malignant/diagnosis* ; Hyperplasia ; Adenocarcinoma/pathology* ; Cystadenocarcinoma, Serous/diagnosis* ; Biomarkers, Tumor ; Carcinoma, Ovarian Epithelial ; Diagnosis, Differential ; Ovarian Neoplasms/pathology* ; Carbohydrates

OBJECTIVE: To investigate the feasibility of a dual-crosslinked injectable hydrogel derived from acellular musclar matrix (AMM) for promoting myoblasts proliferation and myogenic differentiation. METHODS: Firstly, hyaluronic acid was oxidized with NaIO ₄ and methylated to prepare methacrylamidated oxidized hyaluronic acid (MOHA). Then, AMM obtained by washing enzymatically treated muscle tissue was aminolyzed to prepare aminated AMM (AAMM). MOHA hydrogel and AAMM were crosslinked using Schiff based reaction and UV radiation to prepare a dual-crosslinked MOHA/AAMM injectable hydrogel. Fourier transform infrared spectroscopy (FTIR) was used to characterize MOHA, AAMM, and MOHA/AAMM hydrogels. The injectability of MOHA/AAMM hydrogel were evaluated by manual injection, and the gelation performance was assessed by UV crosslinking. The rheological properties and Young's modulus of the hydrogel were examined through mechanical tests. The degradation rate of the hydrogel was assessed by immersing it in PBS. The active components of the hydrogel were verified using immunofluorescence staining and ELISA assay kits. The promotion of cell proliferation by the hydrogel was tested using live/dead staining and cell counting kit 8 (CCK-8) assays after co-culturing with C2C12 myoblasts for 9 days. The effect of the hydrogel on myogenic differentiation was evaluated by immunofluorescence staining and real time quantitative polymerase chain reaction (RT-qPCR). RESULTS: FTIR spectra confirmed the successful preparation of MOHA/AAMM hydrogel. The hydrogel exhibited good injectability and gelation ability. Compared to MOHA hydrogel, MOHA/AAMM hydrogel exhibited higher viscosity and Young's modulus, a reduced degradation rate, and contained a higher amount of collagen (including collagen type Ⅰ and collagen type Ⅲ) as well as bioactive factors (including epidermal growth factor, fibroblast growth factor 2, vascular endothelial growth factor, and insulin-like growth factor 1). The live/dead cell staining and CCK-8 assay indicated that with prolonged incubation time, there was a significant increase in viable cells and a decrease in dead cells in the C2C12 myoblasts within the MOHA/AAMM hydrogel. Compared with MOHA hydrogel, the difference was significant at each time point ( P<0.05). Immunofluorescence staining and RT-qPCR analysis demonstrated that the deposition of IGF-1 and expression levels of myogenic-related genes (including Myogenin, Troponin T, and myosin heavy chain) in the MOHA/AAMM group were significantly higher than those in the MOHA group ( P<0.05). CONCLUSION The MOHA/AAMM hydrogel prepared based on AMM can promote myoblasts proliferation and myogenic differentiation, providing a novel dual-crosslinked injectable hydrogel for muscle tissue engineering.
Hydrogels ; Hyaluronic Acid/pharmacology* ; Vascular Endothelial Growth Factor A/metabolism* ; Tissue Engineering/methods* ; Cell Differentiation ; Myoblasts/metabolism* ; Cell Proliferation