【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 removal efficacy of inflammatory cytokines and blood compatibility of modified PBTNF. 【Methods】 Acrylic acid (AA) was firstly UV-grafted onto the surface of PBTNF to negatively charge the surface of the material. Subsequently, the three positively charged polyelectrolytes, DA, PEI, and CS were respectively electrostatic self-assembled with GO on the surface of PBTNF, forming two layers of film with GO as the outer layer: PBTNF-(DA/GO)2, PBTNF-(PEI/GO)2, PBTNF-(CS/GO)2. 【Results】 Scanning electron microscopy results showed that compared with the PBTNF grafted with AA, the adhesion of particles was observed on the surface of the three modified materials, and the photo shows that the color of the material surface was deepened after electrostatic self-assembly. The results of wettability showed that the surface hydrophilicity was significantly improved, indicating that the electrostatic self-assembled membrane was successfully immobilized on the surface of PBTNF. The removal efficiency (%) of IL-1β for PBTNF-(DA/GO)2, PBTNF-(PEI/GO)2 and PBTNF-(CS/GO)2 were 69.00±7.36 vs -2.35±2.69 vs -1.59±3.26 (P<0.05). The removal efficiency of IL-6 (%) were 40.15±1.86 vs -13.46±5.72 vs -1.21±3.41 (P<0.05). The removal efficiency of IL-8 (%) were 96.90±0.97 vs 17.84±11.74 vs 43.68±17.38 (P<0.05). The removal efficiency of TNF-α (%) was 44.46±2.50 vs 14.90±7.12 vs 20.64±1.22 (P<0.05). Plasma protein adsorption results (total protein, immunoglobulin G, albumin) and red blood cell deformability index showed that there was no statistical difference among the three modified PBTNFs and the control group (P>0.05). Although the red blood cell osmotic fragility (g/L) of the three modified PBTNFs is higher than that of the former: control group vs PBTNF-(DA/GO)2 vs PBTNF-(PEI/GO)2 vs PBTNF-(CS/GO)2: 4.39±0.05 vs 4.62±0.02 vs 4.48±0.03 vs 4.90±0.03 (P<0.05), the hemolysis rate (%) of them were all less than 5%, and PBTNF-(DA/GO)2 performed the lowest hemolysis rate which was (0.03±0.01)% (compared with PBTNF-(PEI/GO)2, P<0.05). The coagulation function test results showed that compared with the control group, the fibrinogen (g/L) of the three modified PBTNFs had no statistical difference (P>0.05); the activated partial thrombo plastin time (S) slightly extended, but all within the normal range of clinical standard; and the prothrombin time (S) of PBTNF-(CS/GO)2 was prolonged(P<0.05). 【Conclusion】 Among the three positively charged polyelectrolytes, including DA, PEI, and CS, PBTNF-(DA/GO)2 performed the best removal rate of inflammatory cytokines, and the blood compatibility evaluation results showed that PBTNF-(DA/GO)2 had no significant effect on red blood cells and coagulation function. Consequently, in the study of inflammatory cytokines adsorption, DA is expected to be the optimal polyelectrolyte assembling with GO for further research.

【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.