Poly (N-isopropylacrylamide) (PNIPAAm), a temperature-responsive polymer, can be potentially applied to replace enzymes or cell scrapers to recover attached cells. Taking full advantage of this unique function of PNIPAAm, cells can be protected from enzymatic hydrolysis and mechanical treatment, thereby to provide ideal seed cells with high quality for biomedical fields. In this review we describe the method to facilitate cell effective adhesion and rapid detachment on thermoresponsive two dimensional surfaces, including selecting special substrate, introducing hydrophilic group, adjusting reactant ratio, controlling polymer thickness/density, providing appropriate external force, so as to effectively improve adherent cell adaptability to thermoresponsive surfaces, depress the risk of bacterial contamination and reduce the effect of low-temperature treatment on the cells. The three dimensional cell culture systems involved in temperature-sensitive microcarriers, scaffolds and gels were briefly discussed. The application based on the platforms for cell culture was also presented.
Acrylic Resins ; Cell Adhesion ; Cell Culture Techniques ; Temperature

The nanoparticle-modified surfaces were built up by alternating deposition of oppositely charged Al2O3 and SiO2 nanoparticles (from 10 nm to 500 nm) solutions. The properties of these nanoparticle-modified surfaces and the controls were investigated by Atomic Force Microscope for topography analysis. Pseudomonas Fluorescence (PF) cell adhesion was evaluated by microscopic determination of the numbers of cells that adhered to the produced slides exposed to PF cell suspensions on static and dynamic condition. The results show that adhesion of PF to both surfaces readily increases with the time of exposition but the adhered numbers of PF on produced surfaces are considerably higher than that on controls in static condition. Cell morphologies on these nanoparticle-modified surfaces studied by inverted microscope show that the adhered PF on the produced surfaces are more in presence of clusters, which contributes more to the total adhering numbers in the late of cell adhesion assays. Meanwhile on controls the cells rarely attained confluence and had a single shape. The significant statistical correlation observed between nanoparticle-modified surfaces and control adds a new concept to the studies of substratum topography influence on cell behavior. The results suggest that nanoparticle-modified surfaces may enhance the interactions between PF cell and slides.
Bacterial Adhesion ; Fluorescence ; Nanoparticles ; Pseudomonas ; cytology ; Silicon Dioxide ; Surface Properties

Rotating wall vessel (RWV) was used for the ex-vivo expansion of umbilical cord blood stem cells to meet the requirement of clinical application in the aspect of quantity and quality of the stem cells. The mononuclear cells (MNCs) from umbilical cord blood were cultured in T-flasks for 24 h, and then inoculated in RWV to culture for 200 h. The nucleated-cell numbers, pH and osmolality of the culture medium were determined every 24 h. The CD34+ cells content was measured and CFU-GM culture was carried out at 144 h and 197 h. Nucleated cells (NC) and CD34+ cells had a 435.5 +/- 87.6 fold expansion and a 32.7 +/- 15.6 fold expansion respectively in 197 h, and CFU-GM (colony-forming unit-granulocyte/macrophage) cells had a 21.7 +/- 4.9 fold expansion. In the whole course of culture, the pH and osmolality of the medium in the RWV were kept in the optimal hematopoietic stem cells' expansion conditions. pH was kept from 7.2 to 7.4, and the osmolality was kept from 290 mmol/kg to 310 mmol/kg. Owing to its structural particularity, the RWV could ensure cells to grow in the suspension state, could simulate the micro-environment of umbilical cord blood, and thus could make the hematopoietic stem cells expand largely in the RWV in short time.
Antigens, CD34 ; metabolism ; Bioreactors ; Cell Culture Techniques ; methods ; Cell Proliferation ; Cells, Cultured ; Culture Media ; Cytokines ; pharmacology ; Fetal Blood ; cytology ; Hematopoietic Stem Cells ; cytology ; physiology ; Humans

Objective To investigate the effect of prevascularized tissue-engineered bone graft on regeneration of femoral bone defects in rats.Methods Models of femoral bone defect were created at the bilateral hind limbs of 20 healthy female 10 week-old rats which were divided into 2 even groups randomly (n =10).In group A,conventional tissue-engineered bone grafts were transplanted into the femoral bone defects;in group B,tissue-engineered bone grafts and vascular bundles were implanted into the femoral defects.At 1,4 and 8 weeks after operation,3 rats were sacrificed each time in each group to harvest samples.The remaining one in each group served as a spare animal.Regeneration of bone defects and degradation of scaffolds were assessed by radiologic modality and hematein eosin staining.Results At week 1,the new bone ratio (BV/TV) was 5.47％ ± 1.90％ in group A and 8.49％ ± 1.26％ in group B,showing no significant difference (P ＞ 0.05);at weeks 4 & 8,the BV/TV were 17.54％ ±2.04％ and 39.73％ ± 4.01％ in group A,significantly lower than those in group B (25.32％ ± 2.15％ and 53.22％ ± 2.94％) (P ＜ 0.05).At weeks 1 & 4,the scaffold degradation ratios (RSV/SV) were 97.33％ ± 2.52％ and 80.60％ ±4.00％,showing no significant differences from those in group B (95.67％ ±3.51％ and 75.22％ ±6.20％) (P ＞ 0.05).At week 8,the scaffold degradation ratio in group A (65.46％ ±4.51％) was significantly higher than that in group B (50.19％ ±4.91％) (P ＜ 0.05).At week 8,hematein eosin staining showed better integration of scaffolds with the femur,faster degradation of the interior scaffolds and greater osteogenetic activity in group B.Conclusion Prevascularization of tissue-engineered bone graft may increase new bone volume and scaffold degradation rate,promoting repair of femoral bone defects in rats.

Objective To systematically evaluate the biomechanical recovery of drilled holes in the femur in SD rats.Methods Eighteen female SD rats were randomized into 3 even groups (n =6).Models of 2-mm drilled holes in bilateral femurs were established in groups A and B with 2 holes on each side while no drilling was performed in group C.Samples were harvested in group A at postoperative 4 weeks,in group B at postoperative 8 weeks while at both 4 and 8 weeks in group C.The samples were evaluated in terms of linear elasticity (compression test),viscoelasticity (relaxation and creep tests) and durability (fatigue failure test).Micro-CT scan was performed to measure the bone volume fraction (BV/TV) and bone mineral density (BMD) of new bone.Sirus red staining was performed to measure regeneration of type Ⅰ collagen of new bone.Results The elasticity modulus,maximum load,compression strength and conditional yield limit in groups A were significantly lower than those in group B which were also significantly lower than those in group C (P ＜ 0.05).At 7,200 s,the relaxation (14.56 ±0.69 MPa) and creep variation (11.37％ ± 0.70％) in group A were significantly higher than those in group B (11.06 0.63 MPa and 8.98％ ± 0.40％) which were also significantly higher than those in group C (6.99 ±0.56 MPa and 5.10％ ±0.23％) (P ＜ 0.05).At the constant amplitude loads from 20 N to 200 N,from 20 N to 300 N and from 20 N to 400 N,the recycling numbers in group A (6,044.3 ±879.7,4,093.3 ±628.5 and 1,919.3 ±847.5) were significantly lower than those in group B (10,192.3 ± 1,109.1,6,750.6 ± 818.0 and 3,376.6 ± 671.3) which were also significantly lower than those in group C (28,068.3 ±2,702.6,11,788.3 ± 1,141.6 and 5,296.3 ± 735.0) (P ＜ 0.05).By micro-CT scan,the BVT and BMD in group A were significantly lower than those in group B which were also significantly lower than those in group C (P ＜ 0.05).The sirus red staining showed the type Ⅰ collagen in the bone defect area was completely regenerated in group B.Conclusion Systematic biomechanical measurements may actually detect the characteristics of biomechanical recovery of bone holes in SD rats,enriching the basic research on the bone damage repairing progress.

BACKGROUND:Vascular regeneration,as one of the crucial repair processes after its onset,necessitates visual analysis between the two. OBJECTIVE:To analyze the literature on ischemic stroke and vascular regeneration in the past decade using bibliometrics and sort out the current status,hotspots,and future research trends in this field. METHODS:We used a bibliometric approach to search the Web of Science database for literature on ischemic stroke and vascular regeneration published between January 2011 and May 2023.The obtained data were systematically analyzed using the VOSviewer visualization software to identify the number of articles,countries,keywords,institutions,authors,citations,and trends. RESULTS AND CONCLUSION:We searched and selected 1 484 articles and found that the relationship between ischemic stroke and vascular regeneration has emerged as a research hotspot in the cerebrovascular field,with the number of published articles continuing to rise.Most of these articles were authored by institutions from China and the United States.Shanghai Jiao Tong University was the most cited institution.The most influential author was Hermann DM,whose article had been cited 1 003 times.The current hot research topics in the field include extracellular vesicles,microRNAs and mesenchymal stem cells,which are being studied for their correlations with relevant diseases.To conclude,the bibliometric analysis provides a visual analysis of ischemic stroke and vascular regeneration,which is found to be an emerging focus as well as a valuable reference for future trends and highlights in ischemic stroke and vascular regeneration.

Objective:To evaluate the reliability and validity of the Chinese version of HEMO-FISS-QoL(HF-QoL) questionnaire (HF-QoL-C) in the Chinese population with hemorrhoids.Methods:From November 2021 to November 2022, a self-constructed general information questionnaire, HF-QoL-C, and the 36-item short form health survey (SF-36), Goligher classification, and Giordano severity of hemorrhoid symptom questionnaire (GSQ) were used to conduct a questionnaire survey on 760 hemorrhoid patients in the anorectal department of six hospitals. The data was analyzed for reliability and validity using SPSS 21.0 and AMOS 26.0 software.Results:The Cronbach's α coefficient of HF-QoL-C and its dimension ranged from 0.831 to 0.960, and the split coefficient was 0.832-0.915. Four common factors were extracted through principal component exploratory factor analysis. Confirmatory factor analysis indicated acceptable structural validity( χ2/ df=8.152, RSMEA=0.097, CFI=0.881, IFI=0.881, NFI=0.867). HF-QoL-C was correlated with SF36 and GSQ( r=-0.694, 0.501, both P<0.01). There were differences in the total score and dimensional scores of HF-QoL-C between surgical and drug treated patients, different grades of Goligher classification for hemorrhoidal disease, and different ranges of hemorrhoid prolapse (all P<0.001). No ceiling effect was found in the total score and the scores of each dimension(0.3%-2.0%). There was a floor effect in both psychological function and sexual activity dimensions (16.7%, 35.1%). Conclusion:HF-QoL-C has good reliability and validity, which can be used to measure the quality of life of Chinese hemorrhoid patients.

Objective: To evaluate the efficacy and safety of sofosbuvir (Nanjing Zhengda Tianqing Pharmaceutical Co., Ltd.) combined with ribavirin in patients with genotype 2 chronic hepatitis C virus infection. Methods: Treatment-naïve or treatment experienced genotype 2 chronic hepatitis C patients from sixteen research centers of China were screened. All subjects received once-daily dose of sofosbuvir (400 mg) combined with ribavirin (body weight < 75 kg, 1 000 mg/day, 400 mg in the morning and 600 mg in the evening; body weight > 75 kg, 1 200 mg/d, 600 mg in the morning and 600 mg in the evening) for 12 weeks. Patients were followed-up for a period of 12 weeks after discontinuation of treatment. Continuous variables were expressed as mean ± standard deviation. The proportion of subjects with virologic response at different follow-up time points and 95% confidence intervals were estimated by maximum likelihood ratio and Clopper-Pearson interval. Results: 132 cases with genotype 2 chronic hepatitis C virus infection from sixteen research centers of China were included, 12 cases of whom were associated with cirrhosis, and the remaining 120 cases were not associated with cirrhosis. One hundred and thirty-one cases completed the study, and one patient lost to follow-up at week 4 after the end of treatment. The sustained virological response rate was 96.2% (95% confidence interval: 92.37% - 99.16%) after 12 weeks of drug withdrawal. Virological relapse occurred in four cases. Of the 132 subjects enrolled in the study, 119 (90.2%) reported 617 adverse events during treatment, of which 359 (76.5%) were TEAE related to sofosbuvir and/or ribavirin. There were nine TEAEs of grade 3 and above, and six cases (4.5%) of them had six severe adverse events. Only one serious adverse event was associated with sofosbuvir and ribavirin (unstable angina pectoris). There were no adverse events leading to drug discontinuation or death. Conclusion Sofosbuvir combined with ribavirin has a high SVR rate in the treatment of genotype 2 chronic hepatitis C virus infection, and most of the adverse events occurred were mild with acceptable safety profile.