BACKGROUND:With the development of tissue engineering, autologous chondrocyte implantation is often used to repair cartilage defects. And poor integration is one of the common reasons that lead to failure repairing. Many models in vitro are used for related studies.
OBJECTIVE:To develop an interface integrated model of tissue engineered cartilage repair in vitro and to evaluate the effect.
METHODS:Cartilage integration model in vitro was established in pigs. Total y 21 cartilaginous rings were obtained and divided into agarose gel group (n=18) and control group (n=3). In agarose gel group, cartilage rings were covered with agarose gel. Chondrocytes were separated and implanted into the ring. The leakage of cells around the cartilage rings was observed. The sections were stained for histological observation at 1, 2, 4 weeks. The average area of neochondrocytes was measured and compared.
RESULTS AND CONCLUSION:The results from the control group were not processed, because there was no chondrocyte aggregate formation in the center of the explant ring due to earlier chondrocyte leakage outside the explant. While no chondrocytes were found outside the explant ring in the agarose gel group. Tissue sections of the agarose gel group were stained by hematoxylin and eosin, alcian blue, Safranin-O and col agen type II immunohistochemistry at 1, 2, 4 weeks. Neochondrocytes proliferated within cartilage ring, and produced extracellular matrix. After 2 weeks of incubation, these inserted chondrocytes were significantly increased. There was no statistical y significant increment between 2 weeks and 4 weeks (P>0.05), although the area was further increased by 4 weeks. This model provides a convenient simulation of the cartilage integration process in vitro and has a potential application in studies of cartilage integration and cartilage tissue engineering.

Objective:To explore the effect of situational simulation interactive training on rehabilitation compliance and motor function of stroke patients with hemiplegia.Methods:A total of 140 hemiplegic patients with stroke from July 2017 to October 2019 in Beijing Rehabilitation Hospital Affiliated to Capital Medical University were selected and divided into control group and observation group, 70 cases in each group. Routine treatment and rehabilitation nursing were used in the control group, and situational simulation interactive training were used in the observation group on the basis of the control group. Both groups were followed up for 6 months. Fugl-Meyer Assessment (FMA), World Health Organization Quality of Life Scale Brief (WHOQOL-BREF), Fugl-Meyer Assessment (FMA), self-made rehabilitation training compliance questionnaire and self-made nursing satisfaction questionnaire were used to evaluate the quality of life, motor ability, cognitive ability before intervention and after follow-up, rehabilitation compliance and nursing satisfaction after follow-up of the two groups.Results:There was no significant difference in FMA, WHOQOL-BREF and MMSE scores between the two groups before intervention ( P>0.05). After follow-up, the scores of FMA, WHOQOL-BREF and MMSE in the observation group were 62.57±6.52, 80.65±9.25, 25.30±3.24, significantly higher than 52.68±7.23, 66.68±8.34, 20.36±3.12 in the control group, the difference was statistically significant ( t value was 8.499, 9.385,9.189, P<0.05). After follow-up, the total compliance rate and satisfaction rate of the observation group were 92.86% (65/70) and 94.29% (66/70), respectively, while those of the control group were 78.57% (55/70) and 80.00% (56/70), respectively, the difference between the two groups was statistically significant (Fisher's exact test, P<0.05). Conclusions:The situation simulation rehabilitation training can effectively improve the motor function, rehabilitation compliance and nursing satisfaction of stroke patients with hemiplegia.

【Objective】 To investigate the effect of Polymerized human cord hemoglobin (PolyCHb) on the sensitivity of hepatocellular carcinoma grafts to lumvalatinib in nude mice. 【Methods】 Hep3B hepatoma cells were subcutaneously transplanted in 18 nude mice to establish tumor graft model. Mice were randomly divided into 3 groups: control group (the saline 90 mg·kg^-1·d^-1), monotherapy group (Lenvatinib10 mg·kg^-1·d^-1), and sensitized group (Lenvatinib mg·kg^-1·d^-1, polyCHB 600 mg/kg twice a week) for 28 days. The tumor volume was measured regularly and the growth curve was drawn. On day 29, the nude mice were sacrificed, the tumor was stripped and weighed, and the pathomorphological differences of each group were evaluated by HE section staining. The expression levels of hypoxia-inducing factor (HIF-1α), CD34, VEGF, CD44, MMP-9, and Glut-1 in tumor tissues of each group were determined by immunohistochemistry. The content of reactive oxygen species (ROS) in tumor tissues of each group was determined by dihydroethyl ingot method. 【Results】 The tumor growth rate and tumor volume in the sensitized group decreased significantly compared with the control group and the solo drug group. On day 29, the tumor volumes of the control group, the monotherapy group and the sensitization group were (2 076.46±350.25)mm^3, (1 035.96±84.16)mm³ and (892.66±104.46)mm^3, respectively. Tumor weight was (1.61±0.52)g, (0.45±0.10)g, and (0.34±0.13)g, respectively. Immunohistochemical score of HIF-1α was 75±23 vs 45±18 vs 18±11, VEGF was 52±8 vs 67±16 vs 35±4, CD34 was 40±7 vs 50±13 vs 28±7, CD44 was 37±15 vs 30±7 vs 15±3, Glut-1 was 74±41 vs 51±30 vs 14±18, MMP-9 was 51±7 vs 62±20 vs 33±3, respectively(P<0.05). The malignant degree of the sensitized group was decreased by HE section staining, which was significantly lower than that of the solo drug group and the control. The ROS content in the sensitized group was higher than that in the solo drug group and the control. 【Conclusion】 PolyCHb can reduce the expression of HIF-1α and its downstream pathway related molecules by increasing oxygenation of hepatocellular carcinoma tissues in nude mice, delay tumor growth and reduce tumor volume in a certain period, thus increase the therapeutic effect of lenvalatinib on hepatocellular carcinoma grafts in tumor bearing nude mice models.

【Objective】 To investigate the effect of polymerized human cord hemoglobin (PolyCHb) on the chemosensitivity of human breast cancer MCF-7 cell subcutaneous xenografts in nude mice and its mechanism. 【Methods】 The MCF-7 cells in exponential growth phase were collected and made into suspension cells at a density of 5×10⁷ cells/mL.Subsequently, the cells were inoculated subcutaneously in the right limb of 18 BALB/c-nu nude mice with 0.2 mL cells per mouse to establish subcutaneous xenograft.When the tumor volume reached about 100 mm³, they were randomly divided into chemotherapy group: doxorubicin 5 mg·kg^-1, once/week; chemotherapy + PolyCHb group: in addition to doxorubicin (chemotherapy group), PolyCHb 600 mg·kg^-1, 3 times/week; the control group: normal saline 90 mg·kg^-1, once/week; all were injected through tail vein continuously for 4 weeks.From the day of injection (d 0), the tumor volume of each group of nude mice was measured every 3 days, and the tumor growth curves were drawn accordingly.After 38 days, the tumor growth observation was completed.The tumor was removed and weighed to calculate the tumor inhibition rate.HE staining, immunohistochemistry and TUNEL method were used to observe the pathological changes of tumor tissue, detect the expression of HIF-1α, and detect tumor cell apoptosis respectively.The content of reactive oxygen species (ROS) of each group was determined by fluorescence staining. 【Results】 The tumor volume (mm³) of chemotherapy + PolyCHb group, chemotherapy group and the control group at day 38 were 196.35±103.45 vs 316.29±62.88 vs 519.42±177.33 (P<0.05), and the tumor inhibition rate (%) of chemotherapy + PolyCHb treatment group and chemotherapy group was 62.20 vs 39.11, respectively.HE staining and TUNEL detection showed that cell necrosis and apoptosis in the growth area of tumor tissue increased in chemotherapy + PolyCHb group.Immunohistochemistry and fluorescence staining showed that HIF-1α expression in chemotherapy + PolyCHb group decreased and reactive oxygen species (ROS) content increased. 【Conclusion】 PolyCHb increases the chemosensitivity of subcutaneous xenograft in nude mice with breast cancer, and its mechanism may be related to the increase of ROS in tumor tissue and the promotion of tumor cell apoptosis.

【Objective】 To investigate the application prospect of platelet-rich plasma lysate (PL) microneedles in the treatment of wound healing by optimizing the preparation process and evaluating the activity of platelet growth factor. 【Methods】 Firstly, hyaluronic acid (HA) was used as needle matrix material, and the concentration of HA was preliminarily determined by investigating the fluidity of HA solution, shape of needle, pressure change performance and puncture performance.Combined with the results of HA dissolution in PL, mechanical properties of PL microneedles and skin puncture, the preparation process of platelet-rich plasma lysis microneedles (PLMN) was optimized to investigate the growth factor activity of PLMN and evaluate the effect of PLMN on wound healing in rats. 【Results】 When the concentration of HA was 30 mg/mL, the solution had good fluidity.The HA microneedles could pierce three layers of sealing film, with the puncture rate at 70%, and the solution had good mechanical properties.When HA was dissolved in PL at a concentration of 30 mg/mL at 4℃, the solution had no crystallization and was with good fluidity.The prepared PLMN showed good needle shape and no bending under HD microscope and scanning electron microscope.In vitro transdermal simulation results showed that PLMN could penetrate 4 layers of sealing membrane, and the puncture rate of the first three layers was more than 85%.In vivo lysis experiment showed that PLMNs could be completely dissolved within 10 min after being inserted into the body.Forty minutes later, the micropores left after the insertion of the microneedle were almost closed, without redness, swelling, erythema and other adverse reactions.In vitro and in vivo transdermal experiments showed that clear blue holes were visible after PLMNs penetrated the skin stain, indicating that the microneedles could pierce the skin barrier.Growth factor detection results showed that the content of platelet-derived growth factor (PDGF-BB) and transforming growth factor (TGFβ1) in platelet lysate were (17.67±1.23) ng/mL and (105.95±2.16) ng/mL, respectively.After PLMNs were prepared and stored at room temperature for 1 week, the content of PDGF-BB(ng/mL) and TGFβ1(ng/mL) were 15.48±2.12 and 56.26±1.53, respectively.Compared with PL(vs 17.67±1.23 and 105.95±2.16), the content of PDGF-BB and TGFβ1 decreased, but still maintained the activity of growth factors.The results of wound healing experiment in rats showed that the wound healing rate (%) of PLMN group on the third day was significantly different from that of the control group(52.51±6.15 vs 33.31±3.60, P<0.05). 【Conclusion】 The PLMN prepared in this experiment has good mechanical properties and can successfully pierce the skin cuticle.It can also maintain the activity of growth factors, and has a good effect on wound healing in rats, which provides a new idea for minimally invasive treatment in the field of tissue repair.

【Objective】 To compare the similarities and differences of polymerized human cord hemoglobin (PolyCHb) and free hemoglobin (FHb) on partial coagulation indexes in vitro, so as to analyze the effect of PolyCHb on coagulation dysfunction. 【Methods】 Using normal saline, two concentrations of FHb and PolyCHb and 36% methemoglobin-containing PolyCHb to mix with fresh whole blood or plasma-rich plasma (PRP) in equal proportions, and incubate at 37°C for 30 minutes to detect prothrombin time (PT), activated partial thromboplastin time (APTT), coagulation factor Ⅱactivity (FⅡ∶C), coagulation factor Ⅴactivity (FⅤ∶C), coagulation factor Ⅷactivity (FⅧ∶C), coagulation factor Ⅸactivity (FⅨ∶C), von Willebrand factor (vWF) and platelet P-selectin (CD62P). 【Results】 1) NaCl group: PT(22.68±1.76) s; APTT(59.58±7.52) s; FⅡ∶C(45.91±3.27) %; FⅤ∶C(30.86±4.43) %; FⅧ∶C(41.32±12.94) %; FⅨ∶C(23.96±5.10) %; vWF (2.14±0.54) mg/L; CD62P(7.44±4.47) %. This group kept as a diluted control. 2) 2% FHb group compared with 7% FHb group: FⅧ∶C (42.16±12.31) %vs (56.64±12.22 ) % (P<0.05). No significant difference was found in other indexes (P>0.05). 3) There is no significant difference between 2% PolyCHb group and 7% PolyCHb group (P>0.05). 4) There is no significant difference between 2% FHb group and 2% PolyCHb group (P>0.05). 5) 7% FHb group compared with 7% PolyCHb group: PT(23.31±1.34)s vs (21.97±1.56)s (P<0.05); APTT(50.12±5.72)s vs (55.43±5.43)s (P<0.05); FⅧ∶C (56.64±12.22) %vs (42.37±13.00)% (P<0.05); vWF (1.41±0.30) mg/L vs (2.25±0.41) mg/L (P< 0.05). No significant difference was found in other indexes (P>0.05). 6) 7% PolyCHb group Compared with Met-PolyCHb group: APTT(55.43±5.43) s vs (46.33±4.86)s (P<0.05); FⅧ∶C (42.37±13) %vs (60.51±10.16) % (P<0.05). No significant difference was found in other indexes (P>0.05). 【Conclusion】 The effect of PolyCHb on coagulation markers is different from FHb. At the concentration of this study, PolyCHb will not cause coagulation disorders. However, if the methemoglobin (MetHb) content is too high, it will activate the intrinsic coagulation pathway.