Effect of BTP2 on agonist-induced vasoconstriction in the mouse aorta in vitro.

BTP2 is a potent inhibitor of store-operated Ca2+ entry (SOCE), which plays a vital role in vasoconstriction. However, the direct effect of BTP2 on the contractile response remains unclear. Here, we investigated the effects and mechanisms of action of BTP2 in the mouse aorta. Isometric tension was measured using a Multi Myograph System with two stainless steel wires. Ca2+ transient was recorded by confocal laser scanning microscope. The results showed that BTP2 markedly suppressed vasoconstriction mediated by SOCE and Ca2+ influx mediated by SOCE. The cumulative concentration of BTP2 had no effect on the baseline of mouse aortic rings, whereas it increased vasoconstriction stimulated by 3 µmol/L Phenylephrine. BTP2 (1 µmol/L) significantly increased vasoconstriction induced by 3 µmol/L Phe or cumulative concentration. BTP2 also promoted noradrenaline-induced aortic contraction. However, Phe- and noradrenaline-induced contraction was not affected by 0.3 or 3 µmol/L BTP2, and BTP2 at 10 µmol/L significantly suppressed aortic contraction. BTP2 inhibited 5-HT-evoked contraction in a concentration-dependent manner. BTP2 at higher concentrations (>3 µmol/L) inhibited CaCl2 -induced and 60 mmol/L K+ -induced contraction with progressive reduction of maximal contraction in a concentration-dependent manner. These results suggest that 1 µmol/L BTP2 increases contraction evoked by α1 adrenoreceptor activation. BTP2 at higher concentrations may inhibit Cav1.2 channels.

Clinical efficacy of bone transport technology in Chinese older patients with infectious bone nonunion after open tibial fracture.

OBJECTIVE: This study was designed for the first time to analyze clinical efficacy of bone transport technology in Chinese older patients with infectious bone nonunion after open tibial fracture. METHODS: This study retrospectively analyzed 220 older patients with infectious bone nonunion after open tibial fracture. There were 110 patients receiving bone transport technology (Group A) and 110 patients receiving membrane induction technique with antibiotic bone cement (Group B). RESULTS: There were 164 male patients and 56 female patients, with an age range of 65 to 71 years and an average age of 67 ± 1.3 years. Traffic accident, high-fall injury and crush injury account for 45.5, 27.7 and 26.8%, respectively. Age, gender, histories, causes and fracture location had no significant difference between the two groups (P > 0.05 for all). Operation time in the Group A was significantly shorter than that in the Group B (P < 0.05). Linear and positional alignment (70.9 vs. 57.3), American Knee Society knee function score (167.7 ± 14.9 vs. 123.8 ± 15.7), Baird-Jackson ankle function score (89.9 ± 3.5 vs. 78.4 ± 4.9), bone healing index (43.0 ± 2.0 vs. 44.3 ± 3.0) and clinical recovery (8.2 vs. 4.5) of patients in the Group A were significantly better than those in the Group B (P < 0.05 for all). Wound infection in the Group A (7.3%) was significantly less than that in the Group B (16.4%; P < 0.05). There were neither a neurovascular complication nor a recurrence of infection in the two groups. CONCLUSION: Bone transport technology achieved better knee and ankle joint function recovery and superior bone healing and clinical efficacy than membrane induction technique with antibiotic bone cement, suggesting that bone transport technique is worthy of extensive promotion to improve clinical condition of older patients with infectious bone nonunion after open tibial fracture.

Biodegradable Zwitterion/PLGA Scaffold Enables Robust Healing of Rat Calvarial Defects with Ultralow Dose of rhBMP-2.

Designing smart scaffolds to reduce administration dosage under the premise of functional healing of bone defects to avoid the severe side effects associated with BMP-2 treatments is one of the essential goals in bone tissue engineering. Here, we report a novel biodegradable PLGA/PSBMA composite as the scaffold for bone tissue engineering. The introduction of zwitterionic PSBMA components can alter the intrinsic burst degradation behavior of PLGA and enable a sustained degradation of the scaffold over the time. The PLGA/PSBMA scaffold can sequester rhBMP-2 and enable a sustained release of the sequestered rhBMP-2 with preserved bioactivity. Furthermore, PLGA/PSBMA scaffolds were able to guide robust healing of critical-sized nonunion calvarial defects (5 mm) at an ultralow dose of 400 ng/scaffold, at which level successful healing of critical-sized bone defects has never been reported. These findings indicate the PLGA/PSBMA scaffolds as novel high-efficiency rhBMP-2 delivery vehicles for bone tissue engineering, and the concept of utilizing the material, which is capable of maintaining the bioactivity of the proteins in the preparation of scaffolds, may open a new avenue for the design of smart scaffolds/vehicles for high-efficiency protein/bioactive drug therapies.

Crocin exerts anti-inflammatory and anti-arthritic effects on type II collagen-induced arthritis in rats.

CONTEXT: Rheumatoid arthritis (RA) is a common systemic auto-immune disease, which is characterized by chronic and symmetry synovial inflammation. Crocin has been reported to exhibit anti-inflammatory effects in animal models. OBJECTIVE: This study investigates the anti-inflammatory and anti-arthritic effects of crocin on type II collagen-induced arthritis (CIA) in Wistar rats. MATERIALS AND METHODS: The CIA rat model was established and randomly divided into five groups with or without crocin treatment (10, 20 or 40 mg/kg), which was started on day 21 after arthritis induction and persisted for 36 days. The symptoms and molecular mechanisms of CIA and crocin-treated CIA rats were compared and investigated. RESULTS: CIA rats presented severe RA symptoms, including high arthritis score, paw swelling, joint inflammation, bone erosion, chondrocyte death, cartilage destruction, enhanced expressions of matrix metalloproteinase (MMP) and pro-inflammatory cytokines. However, crocin could mitigate these symptoms. Crocin (40 mg/kg) exhibited the most efficient therapeutic function on CIA rats: the histological scores of joint inflammation, bone erosion, chondrocyte death, cartilage surface erosion, and bone erosion of CIA rats receiving 40 mg/kg crocin treatment were comparable to the normal rats. MMP-1, -3 and -13 protein expression levels of CIA rats with 40 mg/kg crocin treatment were decreased to levels similar to normal rats. Moreover, crocin could also inhibit the expression of TNF-α, IL-17, IL-6 and CXCL8 in serum and ankle tissues of CIA rats. CONCLUSIONS: In summary, crocin exhibits therapeutic potential for RA, by mitigating the symptoms and inhibiting the pro-inflammatory factor expression.

Zwitterionic betaines over HEPES as the new generation biocompatible pH buffers for cell culture.

Good's buffers have been widely applied in cell/organ culture over the past half a century as biocompatible pH stabilizers. However, the emergence of severe adverse effects, such as cellular uptake, lysosomal autophagic activation, and visible light-induced cytotoxicity, raises serious questions over its biocompatibility while underlying mechanism was unclear. Here we report that riboflavin (RF, component of cell culture medium) generates 1O2, ·OH, and O2 •- under visible light exposure during regular cell manipulation. These short half-life reactive oxygen species (ROS) react with tertiary amine groups of HEPES, producing 106.6 µM of H2O2. Orders of magnitude elevated half-life of ROS in the medium caused severe cytotoxicity and systematic disorder of normal cell functions. We have further designed and validated zwitterionic betaines as the new generation biocompatible organic pH buffers, which is able to completely avoid the adverse effects that found on HEPES and derivate Good's buffers. These findings may also open a new avenue for zwitterionic betaine based materials for biomedical applications.

In situ mineralized PLGA/zwitterionic hydrogel composite scaffold enables high-efficiency rhBMP-2 release for critical-sized bone healing.

Osteoconductive and osteoinductive scaffolds are highly desirable for functional restoration of large bone defects. Here, we report an in situ mineralized poly(lactic-co-glycolic acid)/poly[2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide hydrogel (PLGA/PSBMA) scaffold as a novel high-efficiency carrier for recombinant human bone morphogenetic protein-2 (rhBMP-2) for bone tissue regeneration. By virtue of the oppositely charged structure, the zwitterionic PSBMA component is able to template well-integrated dense mineralization of calcium phosphate throughout the PLGA/PSBMA scaffold. The high affinity between rhBMP-2 and the mineralized matrix, combined with the capability of the zwitterionic hydrogel to sequester and to enable sustained release of ionic proteins, endows the mineralized PLGA/PSBMA scaffolds with high-efficiency sustained release of rhBMP-2 (only 1.7% release within 35 days), thus enabling robust healing of critical-sized (5 mm) nonunion calvarial defects in rats at an ultralow dosage of rhBMP-2 (150 ng per scaffold), at which level successful healing of critical-sized bone defects has never been reported. These findings show that the mineralized PLGA/PSBMA scaffold is promising for bone defect repair.

Poly(hexamethylene biguanide) (PHMB) as high-efficiency antibacterial coating for titanium substrates.

Bacterial associated infection is a remaining urgent challenge in clinic application of metallic implants and devices. Here, we developed a new strategy to combat the bacterial associated infection of titanium alloy (TC4). Novel phosphonate/active ester block polymers (pDEMMP-b-pNHSMA) with identical phosphonate segments (DP = 29) as the metal anchorable ligand but varied active ester segments (DPs = 7, 29, and 64) as the conjugation site for poly(hexamethylene biguanide) (PHMB) were precisely prepared. Through a facile two-step process, the polymeric coating were successfully constructed on TC4 substrates as evidenced by water contact angle and XPS measurements. Through systematical in vitro antibacterial evaluations, robust relationship between the chemical structure of coating polymer and the antibacterial property endowed to the TC4 substrates has been established. Results showed that the block polymer, bearing an active ester segment of 64 repeat units, enabled dense packing of PHMB coating on the TC4 surface, which is able to kill 100% of both S. aureus and E. coli. that seeded without compromising the cytocompatibility of TC4 substrates. Furthermore, PHMB coating could significantly inhibit the colony of the bacteria and consequently reduce the bacterial associated inflammatory reaction as verified by a subcutaneous infection model on rat.

High glucose induces Drp1-mediated mitochondrial fission via the Orai1 calcium channel to participate in diabetic cardiomyocyte hypertrophy.

Mitochondrial dysfunction and impaired Ca2+ handling are involved in the development of diabetic cardiomyopathy (DCM). Dynamic relative protein 1 (Drp1) regulates mitochondrial fission by changing its level of phosphorylation, and the Orai1 (Ca2+ release-activated calcium channel protein 1) calcium channel is important for the increase in Ca2+ entry into cardiomyocytes. We aimed to explore the mechanism of Drp1 and Orai1 in cardiomyocyte hypertrophy caused by high glucose (HG). We found that Zucker diabetic fat rats induced by administration of a high-fat diet develop cardiac hypertrophy and impaired cardiac function, accompanied by the activation of mitochondrial dynamics and calcium handling pathway-related proteins. Moreover, HG induces cardiomyocyte hypertrophy, accompanied by abnormal mitochondrial morphology and function, and increased Orai1-mediated Ca2+ influx. Mechanistically, the Drp1 inhibitor mitochondrial division inhibitor 1 (Mdivi-1) prevents cardiomyocyte hypertrophy induced by HG by reducing phosphorylation of Drp1 at serine 616 (S616) and increasing phosphorylation at S637. Inhibition of Orai1 with single guide RNA (sgOrai1) or an inhibitor (BTP2) not only suppressed Drp1 activity and calmodulin-binding catalytic subunit A (CnA) and phosphorylated-extracellular signal-regulated kinase (p-ERK1/2) expression but also alleviated mitochondrial dysfunction and cardiomyocyte hypertrophy caused by HG. In addition, the CnA inhibitor cyclosporin A and p-ERK1/2 inhibitor U0126 improved HG-induced cardiomyocyte hypertrophy by promoting and inhibiting phosphorylation of Drp1 at S637 and S616, respectively. In summary, we identified Drp1 as a downstream target of Orai1-mediated Ca2+ entry, via activation by p-ERK1/2-mediated phosphorylation at S616 or CnA-mediated dephosphorylation at S637 in DCM. Thus, the Orai1-Drp1 axis is a novel target for treating DCM.

Surface modification of porous PLGA scaffolds with plasma for preventing dimensional shrinkage and promoting scaffold-cell/tissue interactions.

Due to numerous merits, polyesters have been widely used for the preparation of porous scaffolds for biomedical applications. However, insufficient dimensional stability and weak cell interaction are two critical challenges to highly porous polyester scaffolds fulfilling their roles during applications. Here, we report the surface modification of PLGA scaffolds with air plasma for simultaneously tackling the dimensional shrinkage of PLGA scaffolds and improving scaffold-tissue integration. Highly porous PLGA scaffolds with interconnected pore structures and well orientated microtubules were prepared through lyophilization, and an air plasma process with varied duration was applied to the porous scaffolds. Water contact angle measurements indicated that moderate treatment (120 seconds) can significantly increase the wettability without distorting the morphology of and damaging the PLGA scaffolds. Further characterization (SEM, XPS, µ-CT, and theoretical computations) revealed that the plasma treatment enabled the generation of carboxyl groups on the surface of the PLGA scaffold, and the hydrophilic PLGA chain tends to extend under aqueous conditions in comparison to the hydrophobic pristine PLGA chain. Consequently, this could eliminate the hydrophobic-scaffold/water interface and weaken the driving force behind the distortion of the scaffolds in aqueous conditions, and finally inhibit overall shrinkage and maintain the microstructures of the porous scaffolds. Similar results were observed with porous PLA scaffolds, indicating the generality of air plasma treatment in inhibiting the shrinkage of polyester scaffolds. In the meantime, in vitro cell attachment experiments and in vivo subcutaneous implantation results consistently indicated that better maintaining the microstructure could significantly enhance the short-term cell attachment/proliferation on the scaffold and the long-term scaffold-tissue integration. These findings may inspire many creative and efficient strategies for the surface modification of polyester scaffolds to improve their performance for biomedical applications.

Clinical application of arthroscopy-assisted minimally invasive therapy in Chinese elderly with type III Pilon fracture.

OBJECTIVE: Pilon fracture is so complex that its therapy poses a great challenge to surgeons. Few studies have compared arthroscopy-assisted minimally invasive therapy and external fixation combined with limited internal fixation (EFLIF), and an optimal choice of surgical therapy remains unclear in patients with type III Pilon fracture. Moreover, to our knowledge, very few studies have specifically evaluated arthroscopy-assisted minimally invasive therapy in Chinese elderly with type III Pilon fracture. The current study was performed to observe the clinical application of arthroscopy-assisted minimally invasive therapy, compared with EFLIF, in Chinese elderly with type III Pilon fracture. METHODS: There were 230 Chinese elderly with type III Pilon fracture assigned to undergo EFLIF (group A, n=115) or arthroscopy-assisted minimally invasive therapy (group B, n=115), and followed up for 1 year after surgery. RESULTS: Age, sex, causes, sides and types of Pilon fractures were not different between the two groups (P>0.05 for all). Compared with EFLIF, arthroscopy-assisted minimally invasive therapy achieved a better reduction result, bone union and Mazur system (P<0.05 for all). Patient satisfaction, screw loosening and infection prevalence were not different between the two groups (P>0.05 for all). There was no skin necrosis in the two groups. Traumatic arthritis had a significantly lower prevalence in participants with arthroscopy-assisted minimally invasive therapy than EFLIF (P<0.05 for all). CONCLUSION: Compared with EFLIF, arthroscopy-assisted minimally invasive therapy for type III Pilon fracture significantly improved reduction result, bone union and functional status, and decreased traumatic arthritis, demonstrating that arthroscopy-assisted minimally invasive therapy is an optimal choice for type III Pilon fracture in Chinese elderly.

Zwitterionic copolymers bearing phosphonate or phosphonic motifs as novel metal-anchorable anti-fouling coatings.

Developing a facile but efficient anti-fouling surface coating is highly required for metallic implants. Here, we report two kinds of zwitterionic copolymers (both random and block) bearing phosphonic/phosphonate motifs/segments as novel metal anchorable antifouling coatings. Through conventional free radical polymerization and reversible addition-fragmentation chain transfer (RAFT) polymerization, three types of zwitterionic-phosphonic random copolymers with varying mol. ratios (9 : 1, 8 : 2, and 6 : 4) and a phosphonate-zwitterionic block copolymer were precisely prepared based on zwitterionic sulfobetaine methacrylate (SBMA) and phosphonate/phosphonic methacrylate. As evidenced by XPS and water contact angle tests, the two kinds of copolymers with distinguished presenting manners of the metal-anchorable phosphonate/phosphonic motifs were all successfully immobilized on the Ti substrates through a facile one-step post-functionalization. The immobilized copolymers equally exhibited strong inhibition of protein adsorption, platelet adhesion, and bacterial adhesion, endowing significantly improved antifouling ability to the metallic substrates. This work not only provides a novel approach to improve the antifouling ability of Ti substrates, the utilization of phosphonic/phosphonate based copolymers as efficient metal-anchorable coatings may offer a new platform for versatile surface functionalization of many metallic substrates.

Zwitterionic modification of polyurethane membranes for enhancing the anti-fouling property.

Polyurethane (PU) is a biopolymer that has been commonly used for biomedical applications. However, the biofouling phenomenon on the hydrophobic PU surface is one of the crucial issues that embarrassing its applications. Here, we report a facile & efficient approach to improve the anti-biofouling ability of the PU substrates. Active residues were firstly generated on the PU surface by using the low temperature air-plasma treatment, promoting the immobilization of the atom transfer radical polymerization (ATRP) initiators on the surface. Then, three types of zwitterionic polymer brushes, as well as PEG brushes, have been fabricated on the PU substrates through surface-initiated ATRP (SI-ATRP). Robust surface characterizations that capable of revealing the surface chemistry (including X-ray photoelectron spectroscopy (XPS) and wettability tests), and antifouling evaluations of the PU substrates (protein adsorption, platelet adhesion, and cell adhesion measurements) were performed. Results showed that three types of zwitterionic brushes have been successful grafted on the PU surface, respectively. And the three types of zwitterionic brushes, in general, significantly inhibited the protein adsorption, the platelet adhesion, and the cell adhesion on the PU surface, endowing a significantly improved anti-fouling ability to the PU substrates. Furthermore, we found that this facial zwitterionic surface modification did not compromise the mechanical property of the PU substrates. This strategy could be easily exploited to PU-based biomaterials to improve their performance in many applications.

[Clinical analysis of 42 cases uterine myoma by uterine arterial embolization].

OBJECTIVE: To assess the clinical effects and side effects of uterine arterial embolization (UAE) on uterine myoma. METHODS: UAE was performed in 42 patients with uterine myoma. The 4 approximately 5 F cobra catheters were insered into the uterine arteries for treatment. Gelfoam particles mixed with antibiotics were used to embolize the arteries. All patients were followed upto 18 monthes post operation. RESULTS: Arteriography showed that uterine myoma was mainly supplied by uterine arteries and partly by ovarian arteries. All clinical symptoms of 42 patients were relieved. Menorrhagia was reduced 26.3% approximately 75.2%. The volume of uterus myoma decreased 77.7% and 83.0% 12 and 18 months after UAE, respectively and the volume of uterine decreased 54.9% and 62.7%. CONCLUSIONS: UAE was an effective and satisfactory method for the treatment of uterine myoma. Further effects of it should be observed continuously and periodically.

[Uterine arterial embolization in the treatment of adenomyosis].

OBJECTIVE: To assess the clinical efficacy of uterine arterial embolization (UAE) in the treatment of adenomyosis. METHODS: UAE procedures were performed in 23 patients with adenomyosis. Two 3.0 F FASTRACKER-325 tubes were placed into bilateral uterine arteries respectively and the fresh gelfoam particles mixed with antibiotic drugs were used to embolise the arteries. After treatment the symptoms and uterine volume of all patients were investigated. RESULTS: All clinical symptoms of 23 patients relieved. Dysmenorrhea completely disappeared in 19 patients, significantly alleviated in 2 patients. But in other 2 recurred. The uterine volume shrunk significantly [(50 +/- 18)%] vs [(100 +/- 0)%]. The blood flow within the uterine and lesions detect by color doppler flow imaging decreased immediately after UAE. Low-abdominal pain and slight fever were seen after treatment and recovered within 1 - 2 weeks. CONCLUSION: UAE is an effective and safe method in the treatment of adenomyosis.