ABSTRACT
【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.
ABSTRACT
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.
ABSTRACT
【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.
ABSTRACT
【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.
ABSTRACT
【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.