Objective To explore the impact of peptidylarginine deiminase 2(Padi2)-knockout on depressive-like behaviors in socially isolated mice.Methods Using CRISPR/Cas9 technology,a Padi2-knockout(Padi2-/-)mouse model with a C57BL/6J background was established,and the effect of Padi2 knockout was identified by genotyping and RT-qPCR detection.Six-week-old male Padi2-/- mice and wild-type C57BL/6J mice were selected and divided into normal rearing and social isolation groups,with 15 mice per group.The normal rearing group mice were housed with 5 mice per cage,and the social isolation group was housed with 1 mouse per cage,and weighed once a week.After 4 weeks,forced swimming and open field tests were conducted.After the behavioral experiments,brain tissues were taken from mice in each group,and changes in microglia in the brains were detected by immunofluorescence.Results We successfully established Padi2-/- mice.There was no difference in behavior between Padi2-/- mice and C57BL/6J mice in the normal rearing group.After social isolation,compared with C57BL/6J mice,Padi2-/- mice showed a significant increase in depressive symptoms,obvious weight gain,and a significant increase in the number of microglia in brain tissue.Conclusions Padi2 knockout exacerbated depressive-like behaviors and obesity in socially isolated mice,indicating that Padi2 is involved in the progression of depression and may be an effective target for the prevention and treatment of depression.

Objective To explore the impact of peptidylarginine deiminase 2(Padi2)-knockout on depressive-like behaviors in socially isolated mice.Methods Using CRISPR/Cas9 technology,a Padi2-knockout(Padi2-/-)mouse model with a C57BL/6J background was established,and the effect of Padi2 knockout was identified by genotyping and RT-qPCR detection.Six-week-old male Padi2-/- mice and wild-type C57BL/6J mice were selected and divided into normal rearing and social isolation groups,with 15 mice per group.The normal rearing group mice were housed with 5 mice per cage,and the social isolation group was housed with 1 mouse per cage,and weighed once a week.After 4 weeks,forced swimming and open field tests were conducted.After the behavioral experiments,brain tissues were taken from mice in each group,and changes in microglia in the brains were detected by immunofluorescence.Results We successfully established Padi2-/- mice.There was no difference in behavior between Padi2-/- mice and C57BL/6J mice in the normal rearing group.After social isolation,compared with C57BL/6J mice,Padi2-/- mice showed a significant increase in depressive symptoms,obvious weight gain,and a significant increase in the number of microglia in brain tissue.Conclusions Padi2 knockout exacerbated depressive-like behaviors and obesity in socially isolated mice,indicating that Padi2 is involved in the progression of depression and may be an effective target for the prevention and treatment of depression.

【Objective】 To investigate the effect of polymerized human cord hemoglobin (PolyCHb) in chemoimmunotherapy for breast cancer in mice. 【Methods】 A 4T1 breast cancer in situ tumor model was established, and 15 mice were randomly divided into 3 groups: blank group: no intervention; Control group: doxorubicin + PD-1 inhibitor was given intraperitoneal injection of doxorubicin 5 mg·kg^-1 once a week and PD-1 inhibitor 12.5 mg·kg^-1 once a week; Experimental group: DOX+ a-PD-1+ PolyCHb, the usage of DOX and a-PD-1 was the same as above, PolyCHb: PolyCHb 600 mg·kg^-1 was injected into the tail vein, three times a week; The administration period was 4 weeks. During the administration, the tumor volume was recorded 3 times per week, the tumor growth curve of each group was drawn and the tumor inhibition rate was calculated. The mice were killed on the 29th day, and the tumor was removed and weighed to calculate the tumor inhibition rate. Immunofluorescence, HE staining, TUNEL method and immunohistochemistry was used to detect the expression of HIF-1α, observe the pathological changes of tumor tissue, detect the apoptosis of tumor cells, and detect the expression of tumor proliferation index Ki67. 【Results】 Compared with the blank group and the control group, the tumor volume in the experimental group decreased significantly (P<0.05) and the tumor inhibition rate (%) increased significantly (P<0.05). The content of HIF-1α in tumor tissue in experimental group decreased (P<0.05). In the experimental group, the growth area of tumor tissue decreased, accompanied by the increase of necrosis area; The positive rates (%) of apoptosis in tumor tissues of blank group, control group and experimental group were 18.79±0.62, 20.68±1.19 and 41.65±2.99 respectively (F=135.2, P<0.001). In addition, the results of tumor proliferation index Ki67 showed that there was a statistical difference between the control group and the experimental group (P<0.05). 【Conclusion】 PolyCHb increases the sensitivity of chemoimmunotherapy in breast cancer mouse model, and the mechanism may be related to the decrease of HIF-1α expression, the promotion of apoptosis and the inhibition of cell proliferation.

【Objective】 To prepare liposomes encapsulate hemoglobin and paclitaxel(LEHP)to improve tumor hypoxia resistance. 【Methods】 LEHP were prepared by thin-film method, and the particle size, Zeta potential and polydispersity were investigated by nanoparticle size analyzer, and encapsulation efficiency was investigated by high performance liquid chromatography, and the interaction between the liposomes and tumor cells was evaluated by in vitro cell experiments. 【Results】 The optimal preparation conditions of LEHP was as follows: total phospholipid 36 mM, DPPC∶Dope∶cholesterol molar ratio 7∶2∶1, paclitaxel 3 mg, hydrated with 3 mg·mL^-1 Hb-PBS for 30 min at room temperature; The average particle size was (189.17±8.22) nm, polydispersity was 0.14±0.023, paclitaxel encapsulation efficiency was (58.27±2.55)%, hemoglobin content was (0.63±0.05) mg·mL^-1. In vitro cell experiments, the killing effect of LEHP was about 1.5 times that of LEP, about 1.2 times that of LEP, and ROS production was about 1.8 times that of LEP. 【Conclusion】 The preparation conditions of LEHP was optimized, and cell experiments showed that LEHP can promote tumor cell apoptosis by improving hypoxia and increasing ROS production, which is expected to provide a safe and effective new method for drug resistance caused by tumor hypoxia.

【Objective】 To prepare microneedles(MNs) loaded with platelet-rich plasma lysate (PL) using Carboxymethyl chitosan (CMCS), and explore the prospect of PL MNs in the treatment of diabetic wounds. 【Methods】 CMCS was used as the basic material, and an appropriate amount of polyvinylpyrrolidone (PVPK-60) was added to prepare needle materials of different concentrations, and the optimal concentration was determined by investigating the needle formation rate, morphological characteristics and mechanical properties, and the growth factor activity in PL MNs was investigated. The diabetic mice were randomly divided into four groups after the back wound was made, the control group did not do any treatment, the PL smear group was treated with PL smearing, the blank MNs group was treated with MNs without PL, and the PL MNs group was treated with PL microneedles. The effect of PL MNs in wound healing in diabetic mice was evaluated through body observation, H&E staining and immunohistochemistry results. 【Results】 When PVPK60 was 40 mg/mL, the needle formation rate was 100%, the array was complete, the needle body was full, and the needle was sharp. According to the results of mechanical-displacement curve and weight pressure change experiment, the prepared PL MNs have good mechanical strength. The results of growth factor analysis indicated that the content of vascular endothelial growth factor (VEGF) in PL was (625±35) pg/mL, and the content of platelet-derived growth factor-BB (PDGF-BB) was (18 741±1 287) pg/mL. After making the MNs, the VEGF content was (183±2) pg/mL, and the PDGF-BB content was (8049±1157) pg/mL. Although the concentration of growth factors decreased, growth factor activity was still preserved.The results of wound healing experiments in diabetic mice showed that the PL MNs group had better healing, and the wound healing rate was different from that of three groups (P<0.01). The results of H&E staining showed that the PL MNs group had fewer inflammatory cell infiltrates and bleeding spots. The number of fibroblasts and new microvascular in the control group was worse than that in the PL MNs group and the PL smear group. The results of immunohistochemistry indicated that the expression of pro-inflammatory factor IL-6 decreased, while anti-inflammatory factor TGF-β and angiogenesis index CD31 increased in the PL MNs group, which were significantly different from those in the other three groups (P<0.01). 【Conclusion】 The PL MNs prepared in this experiment have good mechanical properties, which has a positive effect on the wound healing of diabetic mice, and provides a new idea for diabetic wound healing.

Most solid tumors suffer from inadequate blood perfusion and oxygenation, leading to a hypoxic microenvironment that accelerates tumor progression and adversely impacts prognosis. Thus, improving oxygenation in tumor tissues is crucial for enhancing the sensitivity and efficacy of tumor therapy. Hemoglobin-based oxygen carriers (HBOCs), as a type of oxygen-carrying nanoparticles, can not only carry and release oxygen but also reach the small blood vessels of obstructive microcirculation to deliver oxygen for anoxic tissues and organs, which are difficult for normal red blood cells to pass through. Studies have demonstrated that the application of HBOCs as a potential nanoscale efficient oxygen carrier in tumor therapy can enhance tissue oxygenation and hold great promise for applications in tumor therapy.This review summarizes the impact of hypoxia in tumors and highlights the progress and potential mechanisms of using HBOCs in tumor radiotherapy, chemotherapy, new kinetic therapy and immunotherapy.

【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.