Drug-coated balloon for treatment of non-atherosclerotic renal artery stenosis-a multi-center study.

INTRODUCTION: Renal artery stenosis (RAS) is a significant reason for secondary hypertension. Impaired renal function and subsequent cardiopulmonary dysfunction could also occur. Patients of non-atherosclerotic RAS has a relatively young age and long life expectancy. Revascularization with percutaneous transluminal angioplasty (PTA) is a viable treatment option. However, restenosis is unavoidable which limits its use. Drug-coated balloon (DCB) has been proven to be effective in restenosis prevention in femoropopliteal arterial diseases and in patients with renal artery stenosis. And PTA for Renal artery fibromuscular dysplasia is safe and clinically successful. Therefore, we could speculate that DCB might have potential efficacy in non-atherosclerotic RAS treatment. METHODS AND ANALYSIS: This will be a randomized multi-center-controlled trial. Eighty-four eligible participants will be assigned randomly in a 1:1 ratio to the control group (plain old balloon, POB) and the experimental group (DCB). Subjects in the former group will receive balloon dilatation alone, and in the latter group will undergo the DCB angioplasty. The DCB used in this study will be a paclitaxel-coated balloon (Orchid, Acotec Scientific Holdings Limited, Beijing, China). Follow-up visits will be scheduled 1, 3, 6, 9, and 12 months after the intervention. Primary outcomes will include controlled blood pressure and primary patency in the 9-month follow-up. Secondary outcomes will include technical success rate, complication rate, and bail-out stenting rate. TRIAL REGISTRATION: ClinicalTrials.gov (number NCT05858190). Protocol version V.4 (3 May 2023).

Multi-responsive mesoporous polydopamine composite nanorods cooperate with nano-enzyme and photosensitiser for intensive immunotherapy of bladder cancer.

Bladder cancer is a common malignancy in the urinary system. Defects of drug molecules in bladder during treatment, such as passive diffusion, rapid clearance of periodic urination, poor adhesion and permeation abilities, lead to low delivery efficiency of conventional drugs and high recurrence rate of disease. In this study, we designed multi-responsive mesoporous polydopamine (PDA) composite nanorods cooperating with nano-enzyme and photosensitiser for intensive immunotherapy of bladder cancer. The strongly adhesive mesoporous PDA with wheat germ agglutinin on nanoparticles could specifically adhere to epithelial glycocalyx and made the nanoparticles aggregate in urinary pathways. Meanwhile, 2,3-dimethylmaleic anhydride could be hydrolysed in acidic conditions of tumour microenvironment, giving it a positive charge (charge reversal), which is more amenable to enter cancer cells. Afterwards, manganese dioxide nanorods could catalyse the reaction of excess H2 O2 in tumour microenvironment to generate active oxygen, so as to change the hypoxic environment in tumour, and achieve a pH-responsive for slow release of PD-L1. After the ICG was irradiated by infrared light, a large amount of singlet oxygen was generated, thereby enhancing the therapeutic effect and reducing toxicity in vivo. Besides, mesoporous PDA with indocyanine green photothermal agent could have a local heat up quickly under the near-infrared light to kill cancer cells, thereby enhancing therapeutic efficacy. Accordingly, this mesoporous PDA composite nanorods shed a light on bladder tumour treatment.

An indirect comparison by Bayesian network meta-analysis of drug-coated devices versus saphenous vein graft bypass in femoropopliteal arterial occlusive disease.

OBJECTIVE: To compare the efficacy and safety between drug-coated devices (DCDs) and bypass surgery with saphenous vein graft (BSV) in femoropopliteal arterial occlusive disease. METHODS: A Bayesian network meta-analysis and indirect comparison were performed. Randomized controlled trials of BSV, bypass surgery with prosthetic graft, bare metal stents, endoluminal bypass (covered stent), percutaneous transluminal angioplasty, and DCDs treating femoropopliteal arterial occlusive disease were collected. The primary end point was target lesion revascularization/target vessel revascularization, and secondary end points were all-cause mortality, limb salvage, and early complications (PROSPERO registry number: CRD42019136530). RESULTS: Forty-two trials and 6867 patients were included. The comparison of DCDs and BSV revealed no significant difference in the 1-year target lesion revascularization/target vessel revascularization (DCDs vs BSV: odds ratio [OR], 0.60; 95% credible interval [CrI], 0.16-2.39). Total early complications from BSV were significantly higher than those from DCDs (DCDs vs BSV: OR, 0.14; 95% CrI, 0.05-0.45), and the main complications of BSV were not death related. There was also no significant difference in systemic early complications (DCDs vs BSV: OR, 0.19; 95% CrI, 0.00-7.82) and 1-year amputation rate (DCDs vs BSV: OR, 2.81; 95% CrI, 0.16-89.53). The 30-day (DCDs vs BSV: OR, 0.38; 95% CrI, 0.00-110.46), 1-year (DCDs vs BSV: OR, 0.96; 95% CrI, 0.24-3.29), 2-year (DCDs vs BSV: OR, 1.60; 95% CrI, 0.64-4.95), and 5-year all-cause mortality rates (DCDs vs BSV: OR, 2.05; 95% CrI, 0.92-4.39) showed no significant differences between DCDs and BSV, although there was a noticeable tendency toward significant results of a higher 5-year mortality rate. CONCLUSIONS: There is no significant difference between DCDs and BSV in short-term efficacy or short- and long-term mortality. Despite traditional BSV remaining the gold standard, DCDs provide a reasonable alternative therapy. In addition, the DCDs have a lower short-term morbidity associated with the procedure at the cost of the possible risk of higher long-term mortality. Clinical trials with more validity are required for a direct comparison between BSV and DCDs.

Smart Responsive Quercetin-Conjugated Glycol Chitosan Prodrug Micelles for Treatment of Inflammatory Bowel Diseases.

The incidence and progression of inflammatory bowel disease are closely related to oxidative stress caused by excessive production of reactive oxygen species (ROS). To develop an efficacious and safe nanotherapy against inflammatory bowel diseases (IBD), we designed a novel pH/ROS dual-responsive prodrug micelle GC-B-Que as an inflammatory-targeted drug, which was comprised by active quercetin (Que) covalently linked to biocompatible glycol chitosan (GC) by aryl boronic ester as a responsive linker. The optimized micelles exhibited well-controlled physiochemical properties and stability in a physiological environment. Time-dependent NMR spectra traced the changes in the polymer structure in the presence of H2O2, confirming the release of the drug. The in vitro drug release studies indicated a low release rate (<20 wt %) in physiological conditions, but nearly complete release (>95 wt % after 72 h incubation) in a pH 5.8 medium containing 10 µM H2O2, exhibiting a pH/ROS dual-responsive property and sustained release behavior. Importantly, the negligible drug release in a simulated gastric environment in 1 h allowed us to perform intragastric administration, which has potential to achieve the oral delivery by mature enteric-coating modification in future. Further in vivo activities and biodistribution experiments found that the GC-B-Que micelles tended to accumulate in intestinal inflammation sites and showed better therapeutic efficacy than the free drugs (quercetin and mesalazine) in a colitis mice model. Typical inflammatory cytokines including TNF-α, IL-6, and iNOS were significantly suppressed by GC-B-Que micelle treatment. Our work promoted inflammatory-targeted delivery and intestinal drug accumulation for active single drug quercetin and improved the therapeutic effect of IBD. The current study also provided an alternative strategy for designing a smart responsive nanocarrier for a catechol-based drug to better achieve the target drug delivery.

One-year outcomes of drug-coated balloon treatment for long femoropopliteal lesions: a multicentre cohort and real-world study.

BACKGROUND: Drug-coated balloons (DCBs) have shown superiority in the endovascular treatment of short femoropopliteal artery disease. Few studies have focused on outcomes in long lesions. This study aimed to evaluate the safety and effectiveness of Orchid® DCBs in long lesions over 1 year of follow-up. METHODS: This study is a multicentre cohort and real-world study. The patients had lesions longer than or equal to 150 mm of the femoropopliteal artery and were revascularized with DCBs. The primary endpoints were primary patency, freedom from clinically driven target lesion revascularization (TLR) at 12 months and major adverse events (all-cause death and major target limb amputation). The secondary endpoints were the changes in Rutherford classification and the ankle brachial index (ABI). RESULTS: One hundred fifteen lesions in 109 patients (mean age 67 ± 11 years, male proportion 71.6%) were included in this study. The mean lesion length was 252.3 ± 55.4 mm, and 78.3% of the lesions were chronic total occlusion (CTO). Primary patency by Kaplan-Meier estimation was 98.1% at 6 months and 82.1% at 12 months. The rate of freedom from TLR by Kaplan-Meier estimation was 88.4% through 12 months. There were no procedure- or device-related deaths through 12 months. The rate of all-cause death was 2.8%. Cox regression analysis suggested that renal failure and critical limb ischaemia (CLI) were statistically significant predictors of the primary patency endpoint. CONCLUSION: In our real-world study, DCBs were safe and effective when used in long femoropopliteal lesions, and the primary patency rate at 12 months by Kaplan-Meier estimation was 82.1%.

Effect of Bone Graft on the Correlation between Clinical Bone Quality and CBCT-determined Bone Density: A Pilot Study.

AIM AND OBJECTIVE: The aim of this pilot study is to explore the possible correlation between radiographic bone density and clinical bone quality in edentulous implant sites with and without a history of bone grafting. MATERIALS AND METHODS: A retrospective evaluation of 273 surgically placed dental implants with adequate preoperative cone-beam computed tomography (CBCT) between 2017 and 2019. Misch classification was used to assess the bone quality, and CBCT grayscale values, utilizing Hounsfield units (HU), were used for radiographic bone density assessment. RESULTS: Sixty-six patients (mean age, 58 years; 43 [65%] female and 23 [35%] male) with 118 implant sites were included. A total of 38 sites with bone grafts were evaluated. Controlling for location, sites with previous bone graft had softer bone quality (p = 0.003) and greater bone density (p <0.001) compared to sites without previous bone grafts. A significant correlation existed between radiographic bone density and clinical bone quality (p ≤0.01). The magnitude of the relationship increased in the absence of bone graft (p <0.001) and became nonsignificant in sites with previous grafting. In sites with allograft, the relationship was not statistically different than those without bone graft (both p ≥0.07), while it was statistically different in sites with xenograft when sites assumed independent (p = 0.02). CONCLUSION: CBCT-determined radiographic bone density was correlated to clinical bone quality in the absence of previous bone grafting, while in the presence of previous bone graft, the radiographic bone density of the edentulous sites seemed to be not associated with the clinical bone density, especially in sites with history of xenograft bone grafting. CLINICAL SIGNIFICANCE: CBCT could be utilized to predict preoperative clinical bone quality in sites without previous bone grafting. When assessing sites with history of bone grafting, the CBCT should be interpreted with caution, especially if xenografts were used.

The fabrication of biomineralized fiber-aligned PLGA scaffolds and their effect on enhancing osteogenic differentiation of UCMSC cells.

The key factor of scaffold design for bone tissue engineering is to mimic the microenvironment of natural bone extracellular matrix (ECM) and guide cell osteogenic differentiation. The biomineralized fiber-aligned PLGA scaffolds (a-PLGA/CaPs) was developed in this study by mimicking the structure and composition of native bone ECM. The aligned PLGA fibers was prepared by wet spinning and then biomineralized via an alternate immersion method. Introduction of a bioceramic component CaP onto the PLGA fibers led to changes in surface roughness and hydrophilicity, which showed to modulate cell adhesion and cell morphology of umbilical cord mesenchymal stem cells (UCMSCs). It was found that organized actin filaments of UCMSCs cultured on both a-PLGA and a-PLGA/CaP scaffolds appeared to follow contact guidance along the aligned fibers, and those cells grown on a-PLGA/CaP scaffolds exhibited a more polarized cellular morphology. The a-PLGA/CaP scaffold with multicycles of mineralization facilitated the cell attachment on the fiber surfaces and then supported better cell adhesion and contact guidance, leading to enhancement in following proliferation and osteogenic differentiation of UCMSCs. Our results give some insights into the regulation of cell behaviors through design of ECM-mimicking structure and composition and provide an alternative wet-spun fiber-aligned scaffold with HA-mineralized layer for bone tissue engineering application.

In vitro corrosion resistance and dual antibacterial ability of curcumin loaded composite coatings on AZ31 alloy: Effect of amorphous calcium carbonate.

Rapid corrosion and bacterial infection are obstacles to put into use biodegradable magnesium (Mg) alloy as biomedical materials. In this research, an amorphous calcium carbonate (ACC)@curcumin (Cur) loaded poly-methyltrimethoxysilane (PMTMS) coating prepared by self-assembly method on micro-arc oxidation (MAO) coated Mg alloy has been proposed. Scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy are adopted to analyze the morphology and composition of the obtained coatings. The corrosion behaviour of the coatings is estimated by hydrogen evolution and electrochemical tests. The spread plate method without or with 808 nm near-infrared irradiation is applied to evaluate the antimicrobial and photothermal antimicrobial ability of the coatings. Cytotoxicity of the samples is tested by 3-(4,5)-dimethylthiahiazo(-z-y1)-2,5-di- phenytetrazoliumromide (MTT) and live/dead assay culturing with MC3T3-E1 cells. Results show that the MAO/ACC@Cur-PMTMS coating exhibited favourable corrosion resistance, dual antibacterial ability, and good biocompatibility. Cur was employed as an antibacterial agent and photosensitizer for photothermal therapy. The core of ACC significantly improved the loading of Cur and the deposition of hydroxyapatite corrosion products during degradation, which greatly promoted the long-term corrosion resistance and antibacterial activity of Mg alloys as biomedical materials.

Fabrication and in vivo osteogenesis of biomimetic poly(propylene carbonate) scaffold with nanofibrous chitosan network in macropores for bone tissue engineering.

A biomimetic poly(propylene carbonate) (PPC) porous scaffold with nanofibrous chitosan network within macropores (PPC/CSNFs) for bone tissue engineering was fabricated by a dual solid-liquid phase separation technique. PPC scaffold with interconnected solid pore wall structure was prepared by the first phase separation, which showed a high porosity of 91.9% and a good compressive modulus of 14.2 ± 0.56 MPa, respectively. By the second phase separation, nanofibrous chitosan of 50-500 nm in diameter was formed in the macropores with little influence on the pore structure and the mechanical properties of PPC scaffold. The nanofibrous chitosan content was calculated to be 9.78% by elemental analysis. After incubation in SBF for 14 days, more apatite crystals were deposited on the pore surface as well as the nanofibrous chitosan surface of PPC/CSNFs scaffold compared with PPC scaffold. The in vitro culture of bone mesenchymal stem cells showed that PPC/CSNFs scaffold exhibited a better cell viability than PPC scaffold. After implantation in rabbits for 16 weeks, the defect was entirely repaired by PPC/CSNFs scaffold, as opposed to the incomplete healing for PPC scaffold. It indicated that PPC/CSNFs scaffold showed a faster in vivo osteogenesis rate than PPC scaffold. Hereby, PPC/CSNFs scaffold will be a potential candidate for bone tissue engineering.

Glutathione-Responsive Pyraclostrobin-Loaded Polyurea Microcapsules for Their Intelligent Controlled Release.

The utilization of intelligent controlled release technology to create stimuli-responsive pesticide formulations has been shown to effectively improve pesticide efficacy and reduce environmental pollution. Herein, a glutathione-responsive release polyurea (PU) microcapsules (MCs) loaded with pyraclostrobin were developed via the interface polymerization method. The pyraclostrobin-loaded PU-MCs showed a regular spherical shape with an average diameter of 480 nm. It also showed good thermal stability and rheological properties. Furthermore, the pyraclostrobin-loaded PU-MCs exhibited favorable wettability on wheat leaves, which was beneficial for enhancing the retention capacity of pesticide droplets and improving pesticide utilization. The pyraclostrobin can be released from MCs and directly proportional to glutathione (GSH) concentrations with Fickian diffusion. Importantly, the control efficacy of pyraclostrobin-loaded PU-MCs against Fusarium graminearum was positively correlated with GSH, indicating a promising candidate for a controlled release of pesticides in agriculture and laying the foundation for further field experiments.

Enhanced cell affinity and osteogenic differentiation of liquid crystal-based substrate via surface bio-functionalization.

Regulation of cell-substrate interactions is an important factor for modulating cell behaviors. Tailoring the physical and chemical properties of the substrates to better mimic the extracellular matrix (ECM) of native tissue is a more effective strategy for enhancing the cell-substrate contact. In current work, we aim at improving surface bioactivity based on the liquid crystalline substrates for the enhancement in cell affinity and osteogenic differentiation. Polydopamine (PDOPA) adhesive coating was used as a reactive platform for the immobilization of chitooligosaccharide (COS) on the octyl hydroxypropyl cellulose ester (OPC) substrate to generate active OPC-PDOPA-COSs liquid crystalline substrates. Results demonstrated that PDOPA-coated OPC surfaces showed remarkably improved hydrophility and increased elastic modulus, leading to better initial cell attachment. Subsequent COS immobilization on the OPC-PDOPA layer could induce promotion of cell proliferation, polarization and cytoskeleton formation. Rat bone marrow mesenchymal stem cells (rBMSCs) seeded on the OPC-PDOPA-COSs showed higher alkaline phosphatase (ALP) activity, calcium deposition, and up-regulated bone-related genes expression, including BMP-2, RUNx-2, COL-I and OCN. In conclusion, surface biofunctionalization on the OPC-based liquid crystalline substrates could come into being the appropriate combination of surface chemistry and liquid crystalline characteristic that simulating in vivo ECM environment, resulting in a favorable support to enhance positive cell-substrate interactions.

Development and In Vitro Biodegradation of Biomimetic Zwitterionic Phosphorylcholine Chitosan Coating on Zn1Mg Alloy.

Zinc (Zn) alloys are promising alternatives to magnesium (Mg)- and iron (Fe)-based alloys because of their moderate corrosion rate and superior biocompatibility. To reduce the mass release of Zn2+ and improve the biocompatibility of Zn implants, the biomimetic zwitterionic polymer layer (phosphorylcholine chitosan-PCCs) was immobilized on the plasma-treated Zn1Mg surface. It is the chemical bonds between the -NH2 groups of the PCCs chain and O-C═O (C═O) groups on the plasma-treated Zn1Mg (Zn1Mg-PP) that contributes to the strong bonding strength between the film and the substrate, by which the PCCs (approx. 200 nm thick) layer can bear a 5.93 N normal load. The electrochemical impedance spectroscopy (EIS) results showed that the PCCs layer remarkably increased the resistance against corrosion attack, protecting substrates from over-quick degradation, and the protective effect of the layer with a thickness of 200 nm lasts for about 24 h. The corrosion products of Zn1Mg-PP-PCC in NaCl solution were determined as Zn5(OH)8Cl2·H2O and Zn3(PO4)2. Besides, the bulk Zn1Mg can trigger more aggressive macrophage activity, while the surface of Zn1Mg-PP and Zn1Mg-PP-PCC and their corrosion products (Zn3(PO4)2) tend to promote the differentiation of macrophages into the M2 phenotype, which is beneficial for implant applications.

Reactive oxygen species-responsive amino acid-based polymeric nanovehicles for tumor-selective anticancer drug delivery.

Stimuli-triggered drug delivery systems have been recognized as a crucial strategy to achieve on-demand drug release at the tumor for improving therapeutic efficacy. In this work, novel biocompatible and biodegradable reactive oxygen species (ROS)-responsive amino acid- based polymeric micelles were developed for tumor-specific drug release triggered by high ROS levels in cancer cells, which were composed of amphiphilic poly(aspartic acid) (PASP) derivatives (PASP-BSer) with phenylborate serine (BSer) side groups as the ROS-responsive unit. A series of PASP-BSer conjugates with different degree of substitution (DS) were synthesized, and their self-assembly and H2O2-responsive behaviors were investigated to optimize the structure of PASP-BSer. In vitro drug loading and release studies confirmed that the optimized PASP-BSer micelles could effectively encapsulate the model anticancer drug doxorubicin (Dox) and exhibit desirable H2O2-triggered release behaviors. More importantly, Dox-loaded PASP-BSer micelles showed high selective cytotoxicity against A549 cancer cells than L929 normal cells. Accordingly, PASP-BSer micelles have significant potential as on-demand drug carriers for anticancer therapy.

Novel synthesis and in vitro drug release of polymeric prodrug: Chitosan-O-isopropyl-5'-O-d4T monophosphate conjugate.

A novel approach to synthesize chitosan-O-isopropyl-5'-O-d4T monophosphate conjugate was developed. Chitosan-d4T monophosphate prodrug with a phosphoramidate linkage was efficiently synthesized through Atherton-Todd reaction. In vitro drug release studies in pH 1.1 and 7.4 indicated that chitosan-O-isopropyl-5'-O-d4T monophosphate conjugate prefers to release the d4T 5'-(O-isopropyl)monophosphate than free d4T for a prolonged period. The results suggested that chitosan-O-isopropyl-5'-O-d4T monophosphate conjugate may be used as a sustained polymeric prodrug for improving therapy efficacy and reducing side effects in antiretroviral treatment.

Anti-biofouling and functionalizable bioinspired chitosan-based hydrogel coating via surface photo-immobilization.

Zwitterionic polymer is a new generation of anti-fouling materials with its good resistance to protein and bacterial adhesion. Constructing the anti-fouling surfaces with zwitterionic polymer has been regarded as an effective approach for improving the biocompatibility and biofunctionality of clinic devices. Herein, we reported a facile approach to construct a biodegradable anti-biofouling and functionalizable hydrogel coating via photo-immobilization using commercial polyethylene terephthalate (PET) films as the substrate, based on zwitterionic glycidyl methacrylate-phosphorylcholine-chitosan (PCCs-GMA). The surface structure and physicochemical properties of zwitterionic PCCs-GMA hydrogel coating were investigated by X-ray photoelectron spectroscopy (XPS), atomic force microscope (AFM) and static water contact angle measurement, and its functionalizable sites were detected by fluorescence labeling. Compared with the pristine PET and cationic chitosan - GMA and hydroxypropyltrimethyl ammonium chloride chitosan (HTCC) - GMA hydrogel coatings, zwitterionic PCCs-GMA hydrogel coating exhibited excellent biocompatibility, and significantly reduced protein adsorption for three model proteins of fibrinogen, immunoglobulin and lysozyme, repelled platelet adhesion, as well as showed a high resistance to bacterial attachment of Escherichia coli and Staphylococcus aureus and superior anti-fouling properties to MRC-5 cells. The results indicated that photo-immobilized zwitterionic PCCs-GMA hydrogel coating has perspective as a dual functional platform with integrated antifouling and further biofunctional properties for various biomedical applications.

Corrosion resistance and antibacterial properties of hydroxyapatite coating induced by gentamicin-loaded polymeric multilayers on magnesium alloys.

As a result of their good biocompatibility, bioactivity, and mechanical properties, magnesium (Mg) alloys have received considerable attention as next generation biodegradable implants. Herein, in order to achieve a proper degradation rate and good antibacterial ability, we reported a novel hydroxyapatite coating induced by gentamicin (GS)-loaded polymeric multilayers for the surface treatment of the Mg alloy. The coating was characterized by X-ray diffraction, fourier transform infrared spectroscopy and scanning electron microscopy. The as-prepared hydroxyapatite coating showed the compact morphology and a well-crystallized apatite structure. This coating could improve the adhesion strength and reduce the corrosion rate of the substrate in simulated body fluid solution. Meanwhile, the drug release and antibacterial experiments demonstrated that the GS loaded specimen revealed a significant antimicrobial performance toward Staphylococcus aureus and had a prolonged release profile of GS, which would be helpful to the long-term bactericidal activity of the Mg implant. This coating showed acceptable biocompatibility via MTT assay and Live/dead staining. Thus, the multilayers-hydroxyapatite coated Mg alloy could improve the corrosion resistance and biocompatibility while delivering vital drugs to the site of implantation.

Corrosion resistance and antibacterial activity of zinc-loaded montmorillonite coatings on biodegradable magnesium alloy AZ31.

A Zinc-loaded montmorillonite (Zn-MMT) coating was hydrothermally prepared using Zn2+ ion intercalated sodium montmorillonite (Na-MMT) upon magnesium (Mg) alloy AZ31 as bone repairing materials. Biodegradation rate of the Mg-based materials was studied via potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS) and hydrogen evolution tests. Results revealed that both Na-MMT and Zn-MMT coatings exhibited better corrosion resistance in Dulbecco's modified eagle medium (DMEM) + 10% calf serum (CS) than bare Mg alloy AZ31 counterparts. Hemolysis results demonstrated that hemocompatibility of the Na-MMT and Zn-MMT coatings were 5%, and lower than that of uncoated Mg alloy AZ31 pieces. In vitro MTT tests and live-dead stain of osteoblast cells (MC3T3-E1) indicated a significant improvement in cytocompatibility of both Na-MMT and Zn-MMT coatings. Antibacterial properties of two representative bacterial strains associated with device-related infection, i.e. Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), were employed to explore the antibacterial behavior of the coatings. The measured inhibitory zone and bacterial growth rate confirmed that Zn-MMT coatings exhibited higher suppression toward both E. coli and S. aureus than that of Na-MMT coatings. The investigation on antibacterial mechanism through scanning electron microscopy (SEM) and lactate dehydrogenase (LDH) release assay manifested that Zn-MMT coating led to severe breakage of bacterial membrane of E. coli and S. aureus, which resulted in a release of cytoplasmic materials from the bacterial cells. In addition, the good inhibition of Zn-MMT coatings against E. coli and S. aureus might be attributed to the slow but sustainable release of Zn2+ ions (up to 144 h) from the coatings into the culture media. This study provides a novel coating strategy for manufacturing biodegradable Mg alloys with good corrosion resistance, biocompatibility and antibacterial activity for future orthopedic applications. STATEMENT OF SIGNIFICANCE: The significance of the current work is to develop a corrosion-resistant and antibacterial Zn-MMT coating on magnesium alloy AZ31 through a hydrothermal method. The Zn-MMT coating on magnesium alloy AZ31 shows better corrosion resistance, biocompatibility and excellent antibacterial ability than magnesium alloy AZ31. This study provides a novel coating on Mg alloys for future orthopedic applications.

Synthesis and biological evaluation of the Zn (II)-IDB complexes appended with oligopolyamide as potent artificial nuclease.

The zinc (II) complexes, which contain oligopolyamide and bis(2-benzimidazolylmethyl)amine (IDB) conjugated by flexible linker, have been successfully synthesized, characterized, and evaluated as DNA cleavage agents. The cleavage activity of these complexes on DNA was studied by electrophoresis. The results showed that the cleavage activity of zinc (II) complexes was enhanced comparing with those without oligopolyamide. Specially, at a high reaction concentration (1.2mM), Zn (II) complex can cleave the plasmid DNA bearing some selectivity. Further, the spectroscopic data suggested that Zn (II) complexes with oligopolyamide backbone possessed A-T (adenine and thymine) rich sequences preference.

[Reversal effect of aloe emodin liposomes on cisplatin resistance line A549/DDP human lung adenocarcinoma cells].

OBJECTIVE: To determine the reversal effect of aloe emodin liposomes (AE-L) on cisplatin resistance human lung adenocarcinoma cell line A549/DDP. METHOD: The un-cytotoxic and cytotoxic concentration of AE-L, and un-cytotoxic concentration of E-L were determined by MTT. The sensitivity of cisplatin were determined by MTT assay in above 3 groups. The intracellular concentration of cisplatin was detected by inductively coupled plasma mass spectrometry (ICP-MS). RESULT: The maximum non-toxic concentration group of AE-L (2.0 mg x L(-1)) increased the sensitivity of cisplatin in A549/DDP, decreased IC50 of cisplatin in A549/DDP from 16.81 mg x L(-1) to 5.86 mg x L(-1), and the hyp-cytotoxic concentration (7.0 mg x L(-1) ) group's IC50 decreased to 4.34 mg x L(-1); AE-L groups significantly increased intracellular concentration of cisplatin in A549/DDP cells. CONCLUSION: The results showed that aloe emodin can reverse multidrug resistance (MDR) of A549/DDP cells and the mechanism might be associated with the increase of intracellular concentration of cisplatin.

Carboxymethyl chitosan-zinc coating for prevention of pin tract infection: An animal model.

BACKGROUND: Pin tract infection is a common problem in orthopedic and traumatology surgery. The aim of this study was to investigate the efficacy of an implant coated with carboxymethyl chitosan-zinc (CMC-Zn2+) in prevention of pin tract infection. MATERIALS AND METHODS: Twenty-four male New Zealand White rabbits were randomized into two equal groups ( n = 12, uncoated and CMC-Zn2+). The implants were colonized with 1 × 106 colony forming units of Staphylococcus aureus and inserted into the lateral right proximal tibia in each rabbit. In each group, at 2 and 4 weeks post-surgery, five and seven rabbits were killed, respectively, to harvest the soft tissues around the implant as well as the hard tissue for histological analysis. The bone cross-sectional view, X-ray, and micro-computed tomography (µCT) were performed. RESULTS: The surgical sites in each animal were evaluated individually at both time points. No evident signs of infections were found in the CMC-Zn2+ group, while a high rate of infection was observed in the uncoated group where minor infections were 85.71% ( n = 12) and major infections 14.29% ( n = 12). The radiography, µCT, and histological analysis showed no evident signs of infection in both groups at 2 weeks post-surgery. However, at 4 weeks, signs of infection were found in all the animals in the uncoated group, whereas in the CMC-Zn2+ group, no infections were observed. The difference between the two groups was highly significant ( p = 0.00). CONCLUSIONS: Our study showed that CMC-Zn2+-coated implants were effective in preventing pin tract infection.