BACKGROUND:Tissue engineering has brought new hope to the clinical challenge of liver failure,and the preparation of plant-derived decellularized fiber scaffolds holds significant importance in liver tissue engineering. OBJECTIVE:To prepare apple tissue decellularized scaffold material by using fresh apple slices and a solution of sodium dodecyl sulfate,and assess its biocompatibility. METHODS:Fresh apples were subjected to decellularization using phosphate buffer saline and sodium dodecyl sulfate solution,separately.Afterwards,the decellularized apple tissues and apple decellularized scaffold materials were decontaminated with phosphate buffer saline.Subsequently,scanning electron microscopy was used to assess the effectiveness of decellularization of the apple materials.Adipose-derived mesenchymal stem cells were extracted from the inguinal fat BALB/C of mice,and their expression of stem cell-related markers(CD45,CD34,CD73,CD90,and CD105)was identified through flow cytometry.The cells were then divided into a scaffold-free control group and a scaffold group.Equal amounts of adipose-derived mesenchymal stem cells were seeded onto both groups.The biocompatibility of the decellularized scaffold with adipose-derived mesenchymal stem cells was evaluated using CCK-8 assay,hematoxylin-eosin staining,and phalloidine staining.Cell adhesion and growth on the scaffold were observed under light microscopy and scanning electron microscopy.Furthermore,the scaffold was subdivided into the non-induced group and the hepatogenic-induced group.Adipose-derived mesenchymal stem cells were cultured on the decellularized apple scaffold,and they were cultured for 14 days in regular culture medium or hepatogenic induction medium for comparison.Immunofluorescent staining using liver cell markers,including albumin,cytokeratin 18,and CYP1A1,was performed.Enzyme-linked immunosorbent assay was used to detect the secretion of alpha fetoprotein and albumin.Additionally,scanning electron microscopy was employed to observe the morphology of the induced cells on the scaffold,verifying the expression of liver cell-related genes on the decellularized scaffold material.Finally,the cobalt-60 irradiated and sterilized decellularized apple scaffolds were transplanted onto the surface of mouse liver and the degradation of the scaffold was observed by gross observation and hematoxylin-eosin staining after 28 days. RESULTS AND CONCLUSION:(1)The scanning electron microscopy results revealed that the decellularized apple scaffold material retained a porous structure of approximately 100 μm in size,with no residual cells observed.(2)Through flow cytometry analysis,the cultured cells were identified as adipose-derived mesenchymal stem cells.(3)CCK-8 assay results demonstrated that the prepared decellularized apple tissue scaffold material exhibited no cytotoxicity.Hematoxylin-eosin staining and phalloidine staining showed that adipose-derived mesenchymal stem cells were capable of adhering and proliferating on the decellularized apple tissue scaffold.(4)The results obtained from immunofluorescence staining and enzyme-linked immunosorbent assay revealed that adipose-derived mesenchymal stem cells cultured on the decellularized apple scaffolds exhibited elevated expression of liver-specific proteins,including albumin,alpha-fetoprotein,cytokeratin 18,and CYP1A1.These results suggested that they were induced differentiation into hepatocyte-like cells possessing functional characteristics of liver cells.(5)The decellularized apple scaffold implanted at 7 days has integrated with the liver,with partial degradation of the scaffold observed.By 28 days,the decellularized apple scaffold has completely degraded and has been replaced by newly-formed tissue.(6)The results indicate that the decellularized scaffold material derived from apple tissue demonstrates favorable biocompatibility,promoting the proliferation,adhesion,and hepatic differentiation of adipose-derived mesenchymal stem cells.

Objective To explore the surgical technique and preliminary safety and aesthetics results of immediate prepectoral implant-based breast reconstruction (BR) with titanium-coated polypropylene mesh (TiLoop Bra) after skin-sparing mastectomy (SSM) or nipple-areola-complex-sparing mastectomy (NSM) for breast cancer patients. Methods The clinical data of consecutive patients who underwent immediate prepectoral implant-based BR with TiLoop Bra after SSM or NSM in West China Hospital from January to July 2022 were retrospectively analyzed. The operation time, intraoperative blood loss, early complication were collected. The preliminary aesthetics results were assessed with the Ueda score and Harris score. Results All the patients were female with a mean age of 39.0±6.8 years. One patient had bilateral breast malignant tumors, and the others had unilateral malignant tumors. Six patients received neoadjuvant chemotherapy before surgery. The mean diameter of the tumors was 24.4±11.9 mm under the color ultrasound before the neoadjuvant chemotherapy. The mean operation time was 153.9±49.4 min. The mean intraoperative blood loss was 29.2±18.3 mL. There were 3 patients with tumor stage 0, 10 patients with stage Ⅰ, 6 patients with stage Ⅱ, 3 patients with stage Ⅲ and 1 patient was found no residual cancer after neoadjuvant chemotherapy. All the patients were successfully followed up with a median follow-up time of 4.8 (3.0-9.2) months. There were 2 (8.3%) patients with major complications, including 1 wound dehiscence and 1 hematoma, and 4 (16.7%) minor complications, including 2 wound dehiscence and 2 infection. The patients with excellent and good Ueda score and Harris score accounted for 82.6% and 87.0%, respectively. None of the patients had animation deformity, capsular contracture, nipple-areola or skin flaps necrosis, or implant loss. During the follow-up period, no local/regional recurrence or distant metastasis was found. Conclusion For selected reliable patients, immediate prepectoral implant-based BR with TiLoop Bra after SSM or NSM for breast cancer patients is safe and has good aesthetics results in the early postoperative period. It has broad application space in patients with suitable indications, and can be promoted as a routine operation.

Articular cartilage (AC) injuries often lead to cartilage degeneration and may ultimately result in osteoarthritis (OA) due to the limited self-repair ability. To date, numerous intra-articular delivery systems carrying various therapeutic agents have been developed to improve therapeutic localization and retention, optimize controlled drug release profiles and target different pathological processes. Due to the complex and multifactorial characteristics of cartilage injury pathology and heterogeneity of the cartilage structure deposited within a dense matrix, delivery systems loaded with a single therapeutic agent are hindered from reaching multiple targets in a spatiotemporal matched manner and thus fail to mimic the natural processes of biosynthesis, compromising the goal of full cartilage regeneration. Emerging evidence highlights the importance of sequential delivery strategies targeting multiple pathological processes. In this review, we first summarize the current status and progress achieved in single-drug delivery strategies for the treatment of AC diseases. Subsequently, we focus mainly on advances in multiple drug delivery applications, including sequential release formulations targeting various pathological processes, synergistic targeting of the same pathological process, the spatial distribution in multiple tissues, and heterogeneous regeneration. We hope that this review will inspire the rational design of intra-articular drug delivery systems (DDSs) in the future.

Objective:To understand the gene characteristics of Sapovirus from diarrhea cases in diarrhoeal disease clinics in Beijing.Methods:In 2019, stool samples were collected from diarrhea cases in diarrhoeal disease clinics in Beijing. The samples were used for the detection of nucleic acid of Sapovirus with real-time RT-PCR. Different RT-PCR methods were used for the partial gene segment amplification in the capsid protein VP1 region and the polymerase RdRp region, and sequencing was conducted for amplified positive products. The sequences were aligned with software BioEdit 7.0.9.0 and analyzed with software Mega 6.06.Results:The overall detection rate of Sapovirus was 2.89% (44/1 522), the detection rate in children under 5 years old was 3.34% (18/539) and 2.64% (26/983) in children aged ≥5 years. The capsid protein VP1 region was sequenced in 23 strains belonging to 8 genotypes (GⅠ.2 had 6 strains, GⅠ.1 and GⅡ.3 had 5 strains, respectively, GⅠ.3 and GⅡ.5 had 2 strains, respectively, GⅠ.5, GⅡ.1 and GⅣ.1 had 1 strain, respectively). A total of 16 strains were detected in the cases aged ≥5 years, and the proportion of GⅠ.2 was highest (37.50%, 6/16), and 7 strains were detected in the cases under 5 years old, the proportions of GⅠ.1 and GⅡ.3 were highest (both 42.86%, 3/7); The internal similarity of each genotype was 95.5%-100.0%, and the similarity with the 51 reference strains of human or sewage sources in different years and different countries was 92.2%-100.0%. The polymerase RdRp region was sequenced in 25 strains belonging to 8 genotypes (GⅡ.P3 had 9 strains, GⅠ.P3 had 4 strains, GⅠ.P1, GⅠ.P2 and GⅡ.P1 had 3 strains, respectively, GⅠ.P5, GⅡ.P5 and GⅣ.P1 had 1 strain, respectively). Fifteen strains were detected in the cases aged ≥5 years, and GⅡ.P3 had the highest proportion (40.00%, 6/15). Ten strains were detected in the cases under 5 years old, and the proportions of GⅠ. P1, GⅡ.P1 and GⅡ.P3 were highest (all 30.00%, 3/10); The internal similarity of each genotype was 94.0%-100.0%, and the similarity with the 39 reference strains of human or sewage sources in different years and different countries was 90.2%-99.1%.Conclusions:Sapovirus is one of the pathogens among diarrhea cases in Beijing. The main genome is GⅠ and GⅡ, and the genotypes are diverse and dispersed. The main genotypes of diarrhea cases in people aged ≥5 years and less than 5 years are different.

Objective:To analyze the genomic characteristics and variations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) derived from an outbreak in inbound flight in Aug, 2022 in Beijing, and provide reference data for disease prevention and control and risk assessment.Methods:Fifty respiratory tract specimens from all cases in this outbreak were collected. The digital PCR (ddPCR) was used to determine the viral loads of the specimens. The full genome of the viruses were sequenced by Next-generation sequencing. Then analuses were performed on the genetic identity, variations and phylogenesis.Results:The median of viral loads in all 50 samples were 5.57×10 4 copies/ml and 5.85×10 4 copies/ml, for ORF1ab gene and N gene, respectively. A total of 46 SARS-CoV-2 genomes were obtained, which all belonged to Omicron/BA.5. Two genome clusters were observed, involving 21 and 7 cases, with a nucleotide sequence identities of 99.993% and 99.997%, respectively. Conclusions:The studied outbreak was composed of two main clusters and other individual cases with Omicron/BA.5 virus overseas.

Objective To investigate the protective effect of adult human liver-derived stem cell exosomes (HLSC-exo) intravenously injected at different time points against acute liver injury induced by concanavalin A (ConA) in mice. Methods HLSC-exo was extracted by differential centrifugation. Western blot was used to measure the expression of the marker proteins CD9 and CD63, and nanoparticle tracking analysis was used to investigate particle size distribution. A total of 56 male C57BL/6 mice were randomly divided into blank control group, ConA model group, and HLSC-exo treatment group. The ConA model group and the HLSC-exo treatment group were further divided into 3-, 6-, and 12-hour subgroups according to the interval between phosphate buffer or HLSC-exo injection and ConA injection. The serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), tumor necrosis factor-α (TNF-α), and interleukin-10 (IL-10) were measured, and the gross morphology and histopathology of the liver were compared between groups. A one-way analysis of variance was used for comparison of continuous data between multiple groups, and the least significant difference t -test was used for further comparison between two groups. Results HLSC-exo was a membranous vesicle with a diameter of 90-110 nm, with a clear saucer-like structure under an electron microscope and marked expression of its specific marker proteins CD9 and CD63. In the blank control group, the levels of ALT and AST were 31.81±6.74 U/L and 69.75±8.30 U/L, respectively. Compared with the blank control group, the 3-, 6-, and 12-hour ConA model groups had significant increases in the levels of ALT and AST (all P < 0.001); compared with the 3-and 6-hour ConA model groups, the 3-and 6-hour HLSC-exo treatment groups had significant reductions in the levels of ALT and AST (225.58±115.59 U/L vs 1989.32±347.67 U/L, 1174.71±203.30 U/L vs 2208.33±349.96 U/L, 303.53±126.68 U/L vs 2534.27±644.72 U/L, 1340.70±262.56 U/L vs 2437.13±288.13 U/L, all P < 0.001); compared with the 6-hour HLSC-exo treatment group, the 3-hour HLSC-exo treatment group had significantly greater reductions ( P < 0.001). In the blank group, the levels of IL-10 and TNF-α were 313.51±10.97 pg/ml and 476.05±7.31 pg/ml, respectively. Compared with the blank control group, the 3-, 6-, and 12-hour ConA model groups had a significant reduction in the level of IL-10 (all P < 0.001); compared with the 3-and 6-hour ConA model groups, the 3-and 6-hour HLSC-exo treatment groups had a significant increase in the level of IL-10(331.61±10.46 pg/ml vs 266.20±8.15 pg/ml, 288.13±10.74 pg/ml vs 264.41±9.12 pg/ml, both P < 0.001); compared with the 6-hour HLSC-exo treatment group, the 3-hour HLSC-exo treatment group had a significantly greater increase ( P < 0.001). Compared with the blank control group, the 3-, 6-, and 12-hour ConA model groups had a significant increase in the level of TNF-α (all P < 0.001); compared with the 3-and 6-hour ConA model groups, the 3-and 6-hour HLSC-exo treatment groups had a significant reduction in the level of TNF-α (478.26±12.99 pg/ml vs 551.31±17.70 pg/ml, 515.58±7.18 pg/ml vs 556.21±11.15 pg/ml, both P < 0.001); compared with the 6-hour HLSC-exo treatment group, the 3-hour HLSC-exo treatment group had a significantly greater reduction ( P < 0.001). Compared with the 3-and 6-hour ConA model groups in terms of the gross morphology and histopathology of the liver, the 3-and 6-hour HLSC-exo treatment groups had a significant reduction in the degree of hepatocyte necrosis, and the 3-hour HLSC-exo treatment group had a basically complete lobular structure, with sporadic spotty necrosis; the 12-hour HLSC-exo treatment group had no significant improvement in hepatocyte necrosis compared with the 12-hour ConA model group. Conclusion Intravenous injection of adult HLSC-exo can alleviate acute liver injury induced by ConA in mice, and injection at 3 hours in advance has the most significant protective effect. Regulation of cytokines is one of the important mechanisms for HLSC-exo to alleviate liver injury.

Objective:To clarify the M protein ( emm gene) types and drug susceptibility characteristic variations of Group A Streptococcus (GAS) in children in Beijing. Methods:The GAS strains isolated from throat swab samples of children diagnosed with scarlet fever and pharyngeal infection in scarlet fever etiology surveillance sentinel hospitals in 16 districts of Beijing in 2018, 2019 and 2021 were analyzed retrospectively.PCR amplification and sequencing were used for emm genotyping, and the minimum inhibitory concentrations (MIC) of 10 antibiotics were determined by the broth microdilution method.The data were analyzed using χ2 test and Fisher′ s exact method between groups. Results:A total of 557 GAS strains were collected, and 11 emm genotypes ( emm1, emm3, emm4, emm6, emm11, emm12, emm22, emm75, emm89, emm128, and emm212) were detected.Of 557 strains, 238 trains were of emm1 type (42.73%), 271 strains were of emm12 type (48.65%) and 48 strains were of other emm types (8.62%). The detection rates of emm1, emm12 and other emm type genes in 2018, 2019, and 2021 were [37.50% (105/280 strains), 57.14% (160/280 strains), 5.36% (15/280 strains)], [49.05% (129/263 strains), 39.54% (104/263 strains), 11.41% (30/263 strains)], and [28.57% (4/14 strains), 50.00% (7/14 strains), 21.43% (3/14 strains)], respectively.In children infected with emm12 in 2018 and 2019, there were more children under 6 years old than children over 6 years old (62.50% vs.46.88%, 46.36% vs.30.36%) (χ 2=7.182, 6.973; all P<0.05). Drug susceptibility testing results suggested that 225 randomly selected GAS strains were all 100.00% sensitive to 7 antibiotics including Penicillin, Levofloxacin, Meropenem, Linezolid, Cefotaxime, Cefepime and Vancomycin.The rates of resistance to Erythromycin, Tetracycline and Clindamycin were [88.57% (93/105 strains), 87.62% (92/105 strains), 86.67% (91/105 strains)], and [94.34% (100/106 strains), 94.34% (100/106 strains), 87.74% (93/106 strains)] in 2018 and 2019, respectively.The test strains were 100.00% (14/14 strains) resistant to the above 3 antibiotics in 2021.MIC 50 and MIC 90 values of Penicillin in 2018, 2019, and 2021 were (0.03 mg/L, 0.03 mg/L), (0.03 mg/L, 0.06 mg/L), and (0.06 mg/L, 0.06 mg/L), respectively.Among 225 GAS strains, 207 strains had drug resistance and were resistant to more than one drug.Specifically, 94.69% (196/207 strains) were resistant to Erythromycin, Tetracycline and Clindamycin.About 4.35% (9/207 strains) were resistant to both Erythromycin and Clindamycin.A total of 0.97% (2/207 strains) were resistant to Erythromycin and Tetracycline. Conclusions:The emm genotypes of GAS in children in Beijing are diverse in 2018, 2019 and 2021.The dominant genotypes are emm12 and emm1, and emm12 is the main epidemiological type.GAS strains maintain highly resistant to Erythromycin, Clindamycin and Tetracycline, and sensitive to Penicillin and other antibiotics.However, MIC 50 and MIC 90 of Penicillin shows an ascending trend.

With the emergence of DNA nanotechnology in the 1980s, self-assembled DNA nanostructures have attracted considerable attention worldwide due to their inherent biocompatibility, unsurpassed programmability, and versatile functions. Especially promising nanostructures are tetrahedral framework nucleic acids (tFNAs), first proposed by Turberfield with the use of a one-step annealing approach. Benefiting from their various merits, such as simple synthesis, high reproducibility, structural stability, cellular internalization, tissue permeability, and editable functionality, tFNAs have been widely applied in the biomedical field as three-dimensional DNA nanomaterials. Surprisingly, tFNAs exhibit positive effects on cellular biological behaviors and tissue regeneration, which may be used to treat inflammatory and degenerative diseases. According to their intended application and carrying capacity, tFNAs could carry functional nucleic acids or therapeutic molecules through extended sequences, sticky-end hybridization, intercalation, and encapsulation based on the Watson and Crick principle. Additionally, dynamic tFNAs also have potential applications in controlled and targeted therapies. This review summarized the latest progress in pure/modified/dynamic tFNAs and demonstrated their regenerative medicine applications. These applications include promoting the regeneration of the bone, cartilage, nerve, skin, vasculature, or muscle and treating diseases such as bone defects, neurological disorders, joint-related inflammatory diseases, periodontitis, and immune diseases.
Nucleic Acids/chemistry* ; Regenerative Medicine ; Consensus ; Reproducibility of Results ; DNA/chemistry*

Objective:To provide evidence for clinical diagnosis, prevention and control of group A rotavirus (RVA) diarrhea, the clinical characteristics of RVA diarrhea in children in Beijing from 2011 to 2018 were analyzed.Methods:From January 2011 to December 2018, 4 819 stool samples from children under 5 years old with diarrhea were collected monthly from 3 hospitals in Beijing. General information, clinical characteristics and other information of children were collected. RVA was detected by enzyme-linked immunosorbent assay (ELISA), genotype was identified by multiple semi-nested RT-PCR. The Vesikari clinical severity score was used to define the severity of diarrhea in children. Dichotomous unconditional logistic regression was used to analyze clinical symptoms and other differences between RVA positive and negative cases. Chi-square and Fisher direct probability tests were used to compare the composition among different groups.Results:A total of 4 819 fecal samples were collected, 953 were positive for RVA, the positive detection rate was 19.78%. The positive rate of RVA was high in the younger age group, and the incidence was high in winter and spring. RVA-positive children had more risk on diarrhea ≥5 times a day, vomiting symptoms, fever, mild dehydration, and Vesikari score ≥11. The positive rate of RVA in watery stool samples (26.13%, 214/819) and infectious diarrhea cases (42.20%, 265/628) was the highest respectively. There were no significant differences in clinical symptoms, clinical diagnoses and fecal traits among children with different RVA genotypes.Conclusions:The clinical symptoms of RVA diarrhea were severe in children. RVA genotype did not affect the clinical symptoms. Stool traits (watery stools) and Vesikari score can assist physicians in diagnosing RVA diarrhea.

Objective:To observe the etiological distribution, clinical presentations and imaging features of pulmonary mycosis that is diagnosed by pathology.Methods:The etiological distribution, clinical presentations and imaging features of patients with pulmonary mycosis, who were collected in the Affiliated Hospital of Jining Medical University from January 2018 to July 2020, were retrospectively analyzed. The diagnosis of all the patients were confirmed by pathological examination, of lung or bronchi tissue that were obtained through operation, bronchoscope or percutaneous lung puncture biopsy.Results:There were 26 patients' (60.47%, 26/43) pathological specimens were obtained by operation, 14 cases (32.56%, 14/43) were obtained by bronchoscope, and 3 cases (6.98%, 3/43) were obtained by percutaneous lung puncture biopsy. Of the 43 patients who were diagnosed pulmonary mycosis by pathology, 27 patients (62.79%, 27/43) suffered from pulmonary aspergillosis, 11 patients (25.58%, 11/43) suffered from pulmonary cryptococcosis, 3 patients (6.98%, 3/43) suffered from pulmonary mucormycosis, and 2 patients (4.65%, 2/43) suffered from pulmonary candidiasis. There were 27 patients (62.79%, 27/43) with pulmonary fungal disease complicating risk factors of fungal infection, including diabetes mellitus (23.26%,10/43), malignant tumor (16.28%, 7/43), bronchiectasis (9.30%, 4/43), hepatitis B virus (HBV) carrier (6.98%, 3/43), taking glucocorticoids (4.65%, 2/43), pulmonary tuberculosis (4.65%, 2/43), and chemotherapy following colon carcinoma operation (2.33%, 1/43). The common clinical presentations included cough (55.81%, 24/43), expectoration (48.84%, 21/43), hemoptysis (37.21%, 16/43), fever (20.93%, 9/43), gasping (18.60%, 8/43), chest pain (16.28%, 7/43), and hoarseness (3.13%, 1/43). Imaging features of chest included lung nodes in 20 cases (46.51%, 20/43), vascular welt sign in 12 cases (27.91%, 12/43), exudative process in 10 cases (23.26%, 10/43), lung mass or consolidation in 8 cases (18.60%, 8/43), cavitary lesions in 7 cases (16.28%, 7/43), thicken bronchus wall and narrow lumina in 6 cases (13.95%, 6/43), air crescent in 5 cases (11.63%, 5/43).Conclusions:The pulmonary aspergillosis and cryptococcosis are mainly in pulmonary mycosis diagnosed by pathology. The common complications are diabetes mellitus and malignant tumor. The common clinical presentations are cough, expectoration, and hemoptysis. The main imaging features of chest are lung nodes and vascular welt sign can be found in most of pulmonary cryptococcosis.