Marine sourced tripeptide SRP and its sustained-release formulation SRP-PLGA-MS exhibiting antihypertensive effect in spontaneously hypertensive rats and HUVECs.

Biopeptides from Sipunculus nudus were reported with good ACE inhibitory activity, and the tripeptide SRP was one with the highest ACE inhibition rate. However, the disadvantage of short half-life limited the development of peptide drugs. Moreover, the distinct mechanism of the peptide inhibiting ACE remained unknown. Thus, in this study, a sustained release formulation of SRP-PLGA-MS was designed and prepared. Its long-lasting antihypertensive effect as well as improvement of vascular pathomorphology was verified in spontaneously hypertensive rat (SHR). In addition, the anti-oxidant activity of SRP in human umbilical vein endothelial cells (HUVECs) was evaluated. The results showed that SRP inhibited the production of ROS and NO, which involve the NADPH oxidase, and Keap1/Nrf2 signaling pathway. This study demonstrated that SRP-PLGA-MS had the potential to develop sustained-release drugs for hypertension treatment.

Diabetes-related Screw Loosening: The Distinction of Surgical Sites and the Relationship among Diabetes, Implant Stabilization and Clinical Outcomes.

OBJECTIVES: Diabetes mellitus (DM) is correlated with poor clinical outcomes in spinal surgery. However, the effect of it on screw stabilization has not been investigated. The aim of this study was to evaluate the screw loosening rate and postoperative outcomes in diabetic patients and to identify potential risk factors associated with loosening. METHODS: This was a retrospective study. Two hundred and forty-three patients who received cervical or lumbar internal fixation between 2015 and 2019 were enrolled. Screw loosening was assessed on radiography, and clinical outcomes were evaluated by the improvement of visual analogue scale (VAS), Oswestry disability index (ODI) or Japanese Orthopaedic Association (JOA) scores. The relationship of DM, screw loosening and clinical outcomes were analyzed with chi-square tests and regression analyses. RESULTS: One hundred and twenty-two patients (50.2%) with diabetes were included in this study. Diabetes led to the increase of the rate of screw loosening in the lumbar spine, while the loosening rate did not vary significantly in the cervical spine. The occurrence of screw loosening in the lumbar spine was more likely to be associated with clinical outcomes for motor performance including walking and sitting. However, no significant effect on JOA and VAS scores in the cervical spine of screw loosening was found. Moreover, the history of DM affected the outcomes of the patients who underwent spinal surgery. CONCLUSION: DM had an adverse effect on screw stabilization. The impaired improvement of clinical outcomes in diabetics after spinal surgery was related to screw loosening. In addition to the direct effects on operative wounds and neural function, the impact on the screws due to DM was also worth noting.

Clinical efficacy of different open approaches in the surgical treatment of thoracolumbar tuberculosis: a single-center retrospective comparative study.

OBJECTIVE: To assess the clinical efficacy of three different surgical approaches in the treatment of thoracolumbar tuberculosis. METHODS: A total of 138 patients with thoracolumbar tuberculosis treated by open surgery were retrospectively analyzed. The surgical methods were divided into anterior, posterior and anterior-posterior combined. The hospital stays, amount of bleeding, operative time, preoperative, postoperative and last follow-up ESR, CRP, Frankel score, ODI, VAS, correction and loss rate of kyphosis, fusion rate and complications were recorded and analyzed. RESULTS: The average follow-up was 66 months. The average hospital stay, operative time and amount of bleeding of the anterior-posterior combined group were higher than other groups (P < 0.05). ESR and CRP of all patients were reduced postoperatively (P < 0.05). No significant difference among the three groups was found in the postoperative correction angle of kyphosis (P < 0.05), while the pre- and postoperative Cobb angle as well as correction rate had significant differences. The posterior approach could achieve better correction, and the loss of correction was more in the anterior group, 40.9 percent of patients performed correction loss. The Frankel score, VAS and ODI were significantly reduced among the three groups, and the incidence rate of complications of the anterior approach was lower than the other groups, with a significant difference (P < 0.05). CONCLUSION: The anterior approach has more advantages and fewer complications, which is supposed to give preference to and could not be replaced by the posterior and anterior-posterior combined approach.

Effects of material nano-topography on the angiogenesis of type H vessels: Size dependence, cell heterogeneity and intercellular communication.

Type H vessel, a vascular subtype in bone, is a critical regulator of osteogenesis, but how material properties affect this organ-specific vessel remains unknown. Here, titania nanotubes were fabricated on bone implant surface to investigate the effects of nano-topography on type H vessels. In vivo, surface nanotubes with 20-100 nm diameters promoted the angiogenesis of type H vessels and bone regeneration in mouse femurs to different extents, with the best effects induced by 70 nm diameter. In vitro, bone-specific endothelial cells (BECs) and artery endothelial cells (AECs) presented significantly different behaviors on the same material. Nanotubes with 20 nm small diameters significantly improved the adhesion, proliferation, type H differentiation of BECs and their paracrine function to regulate pre-osteoblasts (POBs), possibly via binding integrin ß1 on the cell membrane, but these effects weakened when tube diameter increased, which conflicted with the results in vivo. Further study suggested that the better in vivo effects by larger diameters of 70-100 nm might be exerted indirectly through remodeling the regulation from POBs to BECs, highlighting the underappreciated indirect bio-effects of materials via intercellular communication. These suggest that nanoscale material topography makes significant impact on the angiogenesis of type H vessels, directly via binding integrins on the cell membrane of BECs and indirectly via modulating the regulation from osteoblastic cells to BECs, both in a size-dependent manner. Cells of the same type but from different tissues may show different responses to the same material, thus material properties should be tailored to the specific cell population. In research on material-tissue interactions, conclusions from in vitro experiments exposing a single type of cell to material might deviate from the truth in vivo, because materials may indirectly influence the targeted cells through modulating intercellular communication. These provide new insights into material-tissue interactions.

Spatiotemporal Regulation of Injectable Heterogeneous Silk Gel Scaffolds for Accelerating Guided Vertebral Repair.

Osteoporotic vertebral fracture is jeopardizing the health of the aged population around the world, while the hypoxia microenvironment and oxidative damage of bone defect make it difficult to perform effective tissue regeneration. The balance of oxidative stress and the coupling of vessel and bone ingrowth are critical for bone regeneration. In this study, an injectable heterogeneous silk gel scaffold which can spatiotemporally and sustainedly release bone mesenchymal stem cell-derived small extracellular vesicles, HIF-1α pathway activator, and inhibitor is developed for bone repair and vertebral reinforcement. The initial enhancement of HIF-1α upregulates the expression of VEGF to promote angiogenesis, and the balance of reactive oxygen species level is regulated to effectively eliminate oxidative damage and abnormal microenvironment. The subsequent inhibition of HIF-1α avoids the overexpression of VEGF and vascular overgrowth. Meanwhile, complex macroporous structures and suitable mechanical support can be obtained within the silk gel scaffolds, which will promote in situ bone regeneration. These findings provide a new clinical translation strategy for osteoporotic vertebral augmentation on basis of hypoxia microenvironment improvement.

Impairment of type H vessels by NOX2-mediated endothelial oxidative stress: critical mechanisms and therapeutic targets for bone fragility in streptozotocin-induced type 1 diabetic mice.

Rationale: Mechanisms underlying the compromised bone formation in type 1 diabetes mellitus (T1DM), which causes bone fragility and frequent fractures, remain poorly understood. Recent advances in organ-specific vascular endothelial cells (ECs) identify type H blood vessel injury in the bone, which actively direct osteogenesis, as a possible player. Methods: T1DM was induced in mice by streptozotocin (STZ) injection in two severity degrees. Bony endothelium, the coupling of angiogenesis and osteogenesis, and bone mass quality were evaluated. Insulin, antioxidants, and NADPH oxidase (NOX) inhibitors were administered to diabetic animals to investigate possible mechanisms and design therapeutic strategies. Results: T1DM in mice led to the holistic abnormality of the vascular system in the bone, especially type H vessels, resulting in the uncoupling of angiogenesis and osteogenesis and inhibition of bone formation. The severity of osteopathy was positively related to glycemic levels. These pathological changes were attenuated by early-started, but not late-started, insulin therapy. ECs in diabetic bones showed significantly higher levels of reactive oxygen species (ROS) and NOX 1 and 2. Impairments of bone vessels and bone mass were effectively ameliorated by treatment with anti-oxidants or NOX2 inhibitors, but not by a NOX1/4 inhibitor. GSK2795039 (GSK), a NOX2 inhibitor, significantly supplemented the insulin effect on the diabetic bone. Conclusions: Diabetic osteopathy could be a chronic microvascular complication of T1DM. The impairment of type H vessels by NOX2-mediated endothelial oxidative stress might be an important contributor that can serve as a therapeutic target for T1DM-induced osteopathy.

In Situ Regulation of Macrophage Polarization to Enhance Osseointegration Under Diabetic Conditions Using Injectable Silk/Sitagliptin Gel Scaffolds.

As a chronic inflammatory disease, diabetes mellitus creates a proinflammatory microenvironment around implants, resulting in a high rate of implant loosening or failure in osteological therapies. In this study, macroporous silk gel scaffolds are injected at the bone-implant interface for in situ release of sitagliptin that can regulate macrophage response to create a prohealing microenvironment in diabetes mellitus disease. Notably, it is discovered that sitagliptin induces macrophage polarization to the M2 phenotype and alleviates the impaired behaviors of osteoblasts on titanium (Ti) implants under diabetic conditions in a dose-dependent manner. The silk gel scaffolds loaded with sitagliptin elicite a stronger recruitment of M2 macrophages to the sites of Ti implants and a significant promotion of osteointegration, as compared to oral sitagliptin administration. The results suggest that injectable silk/sitagliptin gel scaffolds can be utilized to modulate the immune responses at the bone-implant interface, thus enhancing bone regeneration required for successful implantation of orthopedic and dental devices in diabetic patients.

All-Aqueous-Processed Injectable In Situ Forming Macroporous Silk Gel Scaffolds for Minimally Invasive Intracranial and Osteological Therapies.

Hydrogels are widely utilized in regenerative medicine for drug delivery and tissue repair due to their superior biocompatibility and high similarity to the extracellular matrix. For minimally invasive therapies, in situ forming gel scaffolds are desirable, but technical challenges remain to be overcome to achieve the balance between tissue-like strength and cell-sized porosity, especially for intracranial and osteological therapies. Here, a new method-inspired by the liquid crystalline spinning process in natural silk fibers-is reported for preparing injectable silk gel scaffolds with favorable preclinical efficacy and unique characteristics including 1) in situ gelling for minimally invasive surgeries, 2) controllable porosity for efficient cellular infiltration and desirable degradation, 3) resilient and tunable mechanical properties that are compatible with the modulus regime of native soft tissues, and 4) all-aqueous processing that avoids toxic solvents and enables facile loading of bioactive agents. Moreover, hierarchically structured heterogeneous silk gel scaffolds with variable porosity and bioactive agent gradients within 3D matrices can be achieved for sustained drug release and guided tissue regeneration. Preclinical efficacy studies in rodent models show efficient bacterium and glioma inhibition and positive effects on bone regeneration and vascularization.

The impact of sitagliptin on macrophage polarity and angiogenesis in the osteointegration of titanium implants in type 2 diabetes.

BACKGROUND: Clinical evidence indicates that sitagliptin treatment improves bone quality in diabetic patients, but the mechanisms involved remain elusive. Here, we studied the role of angiogenesis with sitagliptin treatment in diabetes-induced poor osteointegration of titanium implants and the underlying mechanisms. METHODS: In vitro, Human Umbilical Vein Endothelial Cells (HUVECs) incubated on titanium (Ti) surface were subjected to 1) normal milieu (NM); 2) diabetic milieu (DM); 3) DM + sitagliptin; 4) NM + macrophage; 5) DM + macrophage; or 6) DM + macrophage + sitagliptin. Microphage and HUVECs were cultured alone or co-cultured in a Transwell system. In vivo, DM was induced by high-fat diet and administration of streptozotocin (STZ) in rats. Titanium screws were implanted in the femurs of rats in three groups: Control, DM, Sitagliptin-treated DM. RESULTS: In vitro, when cells were incubated alone, DM caused M1 polarization of macrophage, evidenced by the increased iNOS and decreased CD206 expressions, and obvious dysfunctions of HUVECs. The DM-induced injury of endothelial cells were significantly worsened when the two cells were co-cultured. The addition of sitagliptin markedly reversed the changes of macrophage but not of HUVECs in DM when cells were cultured alone. When cells co-cultured, however, both the abnormal macrophage polarization and the endothelial impairment in DM was significantly alleviated by sitagliptin. In vivo, compared with normal animals, DM animals showed imbalanced M1/M2 polarization, angiogenesis inhibition and poor bone formation on the bone-implant interface (BII), which were significantly ameliorated by sitagliptin treatment. CONCLUSION: Our results demonstrate macrophage polarization imbalance as a crucial mechanism underlying the impaired angiogenesis and bone healing in diabetes, and provide sitagliptin as a promising novel drug for biomaterial-engineering to improve the osteointegration of titanium implants in diabetic patients.

Thermo-responsive mesoporous silica/lipid bilayer hybrid nanoparticles for doxorubicin on-demand delivery and reduced premature release.

Hybrid nanocarriers based on mesoporous silica nanoparticles (MSNs) and supported lipid bilayer (SLB) have been studied as drug delivery system. It still remains challenges to develop these nanocarriers (SLB-MSNs) with on-demand drug release profile for chemotherapy. Here, we reported the biocompatible SLB-MSNs with high drug loading, which could release doxorubicin (DOX) in response to hyperthermia and reduce premature release. After synthesis of MSNs via a sol-gel procedure, the thermo-responsive SLB was deposited on the MSNs by sonication to completely seal the mesopores. The obtained SLB-MSNs consisted of 50 nm-sized MSN cores and 6.3 nm-thick SLB shells. Due to the big surface and pore volume of MSNs, the high drug loading content (7.30±0.02%) and encapsulation efficiency (91.16±0.28%) were achieved. The SLB blocking the mesopores reduced 50% of premature release and achieved on-demand release in a thermo-responsive manner. Moreover, SLB-MSNs showed good hemocompatibility at any tested concentration (25-700µg/mL), while bare MSNs caused 100% of hemolysis at concentration larger than 325µg/mL. In addition, in vitro U251 cell uptake experiment demonstrated that compared with uncapped MSNs, SLB-MSNs could prevent untargeted cellular uptake of DOX owing to reduced premature release and steric hindrance of PEG, which would be beneficial to minimize toxicity for healthy tissues. These results indicated that SLB-MSNs with thermo-responsive release capacity possessed great potential in future synergistic thermo-chemotherapy.

A novel azopyridine-based Ru(II) complex with GSH-responsive DNA photobinding ability.

A novel azopyridine-based Ru(II) complex [Ru(bpy)2(L1)2](2+) (bpy = 2,2'-bipyridine, L1 = 4,4'-azopyridine) was designed and synthesized as a potential glutathione (GSH)-responsive photoactivated chemotherapy (PACT) agent, the DNA covalent binding capability of which can only be activated after GSH reduction and visible light irradiation.

Two novel BODIPY-Ru(ii) arene dyads enabling effective photo-inactivation against cancer cells.

BODIPY (boron dipyrromethene) derivatives and Ru(ii) complexes are two types of functional compounds that have found wide applications in the fields of biology and medicine. We herein synthesized two new Ru(ii) arene complexes based on an iodized BODIPY-containing pyridine (py-I-BODIPY) ligand, [(p-cym)Ru(bpy)(py-I-BODIPY)](2+) (2) and [(p-cym)Ru(2-pydaT)(py-I-BODIPY)](2+) (3), where p-cym = para-cymene, bpy = 2,2'-bipyridine, and 2-pydaT = 2,4-diamino-6-(2-pyridyl)-1,3,5-triazine. The photophysical, photochemical and photobiological properties of 2 and 3 were compared with that of [(p-cym)Ru(bpy)(py-BODIPY)](2+) (1). While 1 undergoes efficient monodentate ligand dissociation upon visible light irradiation and therefore may photobind DNA as a potential photoactivated chemotherapy (PACT) agent, 2 and 3 can generate (1)O2 effectively and thus may serve as photosensitizers in photodynamic therapy (PDT). In electrophoresis experiments, 2 and 3 are even able to retard the mobility of plasmid DNA in the dark at high concentrations. More importantly, the cytotoxicities of 2 and 3 against human ovarian adenocarcinoma SKOV3 cells are enhanced about ten times under irradiation, leading to cytotoxicities more than one order of magnitude higher than that of cisplatin, demonstrating an efficient hybridization of the iodized BODIPY chromophore and the Ru(ii) arene complex.

Tumor-specific upregulation of human leukocyte antigen-G expression in bladder transitional cell carcinoma.

Human leukocyte antigen-G (HLA-G) is a potent immunosuppressive molecule that induces functional silencing of both innate and adaptive immune responses. The relevance of the aberrant HLA-G expression in malignant contexts has been intensively investigated. However, its expression status and clinical significance in bladder cancer remain to be elucidated. In the current study, HLA-G expression in 75 primary bladder transitional cell carcinoma (TCC) lesions was analyzed with immunohistochemistry, and relationship between HLA-G expression and clinical parameters, including disease stage was evaluated. Plasma soluble HLA-G levels were analyzed in 15 TCC patients and 109 normal controls. Data revealed that HLA-G was expressed in 68.0% (51/75) primary TCC lesions, whereas it was undetectable in adjacent normal bladder tissues. The proportion of HLA-G expression in TCC samples varied from negative to 100%, and no significant association was observed for the HLA-G expression status with the patient age, gender, and disease stage. Furthermore, no significance for sHLA-G levels was observed between the TCC patients and normal controls (median 10.75 vs 8.69 U/ml, p = 0.578). Given its immunotolerant properties, our finding suggested that lesion HLA-G expression upregulated in bladder TCC lesions might be an additional mechanism for tumor cells evading from host immunosurveillance; however, its clinical relevance needs further investigation.

[A comparative study of nephrectomy and radical nephrectomy for renal cell carcinoma].

OBJECTIVE: To compare the clinical efficacy and safety of nephrectomy versus radical nephrectomy for renal cell carcinoma (RCC). METHODS: A total of 134 patients with renal carcinoma without metastasis in lymphatic system and distant sites were recruited. In random, 69 cases of renal cell carcinoma were elected for nephrectomy and the others radical nephrectomy. The operating time, blood loss, fasting time, postoperative hospital stay, information of tumor recurrence and metastasis, survival time without tumor, survival rate and perioperative complication were compared between two groups. RESULTS: In cases of nephrectomy, the operating time ranged from 60 - 135 minutes and blood loss 70 - 100 ml. In 4 cases, membrana pleuro-peritonealis was damaged. The fasting time ranged from 6 - 24 hours and postoperative hospital stay 5 - 8 days; the staging of all 69 cases was detected; follow-up studies ranged from 5 - 15 years, finding 1 case tumor metastasis in adrenal body and 1 case recurrent tumor in cases of radical nephrectomy, operating time ranged from 105 - 185 minutes and blood loss 150 - 2000 ml. Membrana pleuro-peritonealis was breached in 3 cases. The fasting time ranged from 12 - 90 hours and postoperative hospital stay 8 - 12 days. The staging of all 65 cases was detected. Follow-up studies of 5 - 15 years revealed 1 case of tumor metastasis in brain and 1 case of recurrent tumor. There was no significant difference in perioperative complication, tumor recurrence, tumor metastasis and survival time without tumor between those two groups (P > 0.05). The blood loss, operating time, fasting and postoperative hospital stay were less than that in radical nephrectomy group (P < 0.05). CONCLUSION: In patients without metastasis in lymphatic system and distant sites, nephrectomy is both effective and safe. It has the advantages of a short operating time, a short postoperative hospital stay and less damage and blood loss than radical nephrectomy.

[Preventive strategies and causes of common complications of ureteroscopy].

OBJECTIVE: To discuss the causes of common complications of ureteroscopy and how to prevent them. METHODS: A total of 768 cases of common complications of ureteroscopy were retrospectively analyzed from February 2004 to February 2009. RESULTS: The intra-operative complications were failed entry (n = 6, 0.78%), ureterostoma injury and ureterostoma submucosa pseudocana (n = 12, 1.56%), ureteral perforation (n = 16, 2.08%), stone displacement (n = 13, 1.87%) and ureteral mucosa evulsion (n = 3, 0.39%). And the post-operative complications were lumbago or renal colic (n = 11, 1.43%), infection (n = 9, 1.17%)and severe hematuria (n = 5, 0.65%). CONCLUSION: Skillful operative techniques and strict indications are key to reducing complications of ureteroscopy.