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1.
Oper Neurosurg (Hagerstown) ; 25(3): 209-215, 2023 09 01.
Article in English | MEDLINE | ID: mdl-37345935

ABSTRACT

BACKGROUND AND OBJECTIVES: One of the risks involved after long-segment fusions includes proximal junctional kyphosis (PJK) and proximal junctional failure (PJF). There are reported modalities to help prevent this, including 2-level prophylactic vertebroplasty. In this study, our goal was to report the largest series of prophylactic cement augmentation with upper instrumented vertebra (UIV) + 1 vertebroplasty and a literature review. METHODS: We retrospectively reviewed our long-segment fusions for adult spinal deformity from 2018 to 2022. The primary outcome measures included the incidence of PJK and PJF. Secondary outcomes included preoperative and postoperative Oswestry Disability Index, visual analog scale back and leg scores, surgical site infection, and plastic surgery closure assistance. In addition, we performed a literature review searching PubMed with a combination of the following words: "cement augmentation," "UIV + 1 vertebroplasty," "adjacent segment disease," and "prophylactic vertebroplasty." We found a total of 8 articles including 4 retrospective reviews, 2 prospective reviews, and 2 systematic reviews. The largest cohort of these articles included 39 patients with a PJK/PJF incidence of 28%/5%. RESULTS: Overall, we found 72 long-segment thoracolumbar fusion cases with prophylactic UIV cement augmentation with UIV + 1 vertebroplasty. The mean follow-up time was 17.25 months. Of these cases, 8 (11.1%) developed radiographic PJK and 3 (4.2%) required reoperation for PJF. Of the remaining 5 patients with radiographic PJK, 3 were clinically asymptomatic and treated conservatively and 2 had distal fractured rods that required only rod replacement. CONCLUSION: In this study, we report the largest series of patients with prophylactic percutaneous vertebroplasty and UIV cement augmentation with a low PJK and PJF incidence of 11.1% and 4.2%, respectively, compared with previously reported literature. Surgeons who regularly perform long-segment fusions for adult spinal deformity can consider this in their armamentarium when using methods to prevent adjacent segment disease because it is an effective modality in reducing early PJK and PJF that can often result in revision surgery.


Subject(s)
Kyphosis , Spinal Fusion , Vertebroplasty , Humans , Adult , Retrospective Studies , Prospective Studies , Spinal Fusion/methods , Spine/surgery , Kyphosis/prevention & control , Vertebroplasty/methods , Bone Cements/therapeutic use
2.
Addict Behav ; 105: 106350, 2020 06.
Article in English | MEDLINE | ID: mdl-32070907

ABSTRACT

BACKGROUND: Neuropsychological impairments found in recently detoxified patients with alcohol use disorder (AUD) can limit the benefit of psychosocial treatments and increase the risk of relapse. These neuropsychological deficits are reversible with abstinence. The aim of this retrospective clinical study was to investigate whether a short-term stay as inpatients in a convalescent home enables neuropsychological deficits observed in recently detoxified AUD patients to recover and even performance to return to normal. METHODS: Neuropsychological data were collected in 84 AUD patients. Five neuropsychological components were assessed before and after a three-week stay in a convalescent home offering multidisciplinary support. Baseline and follow-up performance were compared in the entire group of patients and in subgroups defined by the nature and intensity of the therapy (OCCASIONAL: occasional occupational and physical therapy; INTENSIVE: intensive occupational and physical therapy and neuropsychological training). RESULTS: In the entire group of patients, neuropsychological performance significantly improved between baseline and follow-up for all 5 components and even returned to a normal level for 4 of them. The ratio of patients with impaired performance was significantly lower at follow-up than baseline examination for 3 components in the INTENSIVE group only. CONCLUSION: Recently detoxified AUD patients with cognitive deficits benefit from a short-term stay in an environment ensuring sobriety and healthy nutrition. Cognitive recovery may be enhanced by intensive care including neuropsychological training. Alcohol programs could be postponed in patients with cognitive deficits in order to offer psychosocial treatment when patients are cognitively able to benefit from it.


Subject(s)
Alcoholism/complications , Cognitive Dysfunction/complications , Cognitive Dysfunction/rehabilitation , Recovery of Function , Alcohol Abstinence/psychology , Alcoholism/therapy , Female , France/epidemiology , Humans , Inpatients/statistics & numerical data , Male , Middle Aged , Neuropsychological Tests , Residential Facilities , Retrospective Studies
3.
J Stroke Cerebrovasc Dis ; 28(5): 1329-1337, 2019 May.
Article in English | MEDLINE | ID: mdl-30772159

ABSTRACT

BACKGROUND: The two most common approaches to thrombectomy of emergent large vessel occlusion (direct aspiration and primary stent retriever thrombectomy) have been extensively studied; however, the detailed benefit and risk comparison is largely unknown. OBJECTIVE: To conduct a systematic review and meta-analysis to compare radiographic and clinical outcomes between the use of primary stent retrievers and direct aspiration in management of acute ischemic stroke. METHODS: PubMed database was searched for studies between September 1, 2012 and December 31, 2017 with acute ischemic stroke patients. RESULTS: We identified 64 studies with 6875 patients in the primary stent retriever group and 25 studies with 2252 patients in the aspiration group. Primary aspiration alone, without the need of rescue stent retriever devices within the aspiration cohort, was performed in 65% of 2252 patients. There was no difference in the distribution of emergent large vessel occlusion based on occlusion site, age, baseline National Institutes of Health Stroke Scale, or the use of intravenous tPA (P = .19, .051, .23, and .093, respectively). Successful recanalization rates, defined as thrombolysis in cerebral Infarction 2b/3, were significantly higher in the aspiration group than the primary stent retriever group (89% versus 80%, P < .0001). No significant difference in good clinical outcome, defined as modified Rankin scale 0-2 (aspiration 52% versus stent 48%, P = .13), symptomatic intracerebral hemorrhage (aspiration 5.6% versus stent 7.2%, P = .07), and mortality at 3 months (aspiration 15% versus stent 19%, P = .10). CONCLUSIONS: Both aspiration-first (including the subsequent use of stent retriever) and primary stent retriever thrombectomy approaches are equally effective in achieving good clinical outcomes. Our study suggests that direct aspiration with or without subsequent use of stent retriever is a safe and effective alternative to primary stent retriever in acute ischemic stroke.


Subject(s)
Endovascular Procedures , Stroke/therapy , Thrombectomy/methods , Aged , Disability Evaluation , Endovascular Procedures/adverse effects , Endovascular Procedures/instrumentation , Endovascular Procedures/mortality , Female , Humans , Male , Middle Aged , Recovery of Function , Risk Factors , Stroke/diagnosis , Stroke/mortality , Stroke/physiopathology , Suction , Thrombectomy/adverse effects , Thrombectomy/instrumentation , Thrombectomy/mortality , Time Factors , Treatment Outcome
4.
Atherosclerosis ; 283: 52-60, 2019 04.
Article in English | MEDLINE | ID: mdl-30782561

ABSTRACT

BACKGROUND AND AIMS: Primary hypobetalipoproteinemia is generally considered a heterogenic group of monogenic, inherited lipoprotein disorders characterized by low concentrations of LDL cholesterol and apolipoprotein B in plasma. Lipoprotein disorders include abetalipoproteinemia, familial hypobetalipoproteinemia, chylomicron retention disease, and familial combined hypolipidemia. Our aim was to review and analyze the results of the molecular analysis of hypolipidemic patients studied in our laboratory over the last 15 years. METHODS: The study included 44 patients with clinical and biochemical data. Genomic studies were performed and genetic variants were characterized by bioinformatics analysis. A weighted LDL cholesterol gene score was calculated to evaluate common variants associated with impaired lipid concentrations and their distribution among patients. RESULTS: Twenty-three patients were genetically confirmed as affected by primary hypobetalipoproteinemia. In this group of patients, the most prevalent mutated genes were APOB (in 17 patients, with eight novel mutations identified), SAR1B (in 3 patients, with one novel mutation identified), ANGPTL3 (in 2 patients), and MTTP (in 1 patient). The other 21 patients could not be genetically diagnosed with hypobetalipoproteinemia despite presenting suggestive clinical and biochemical features. In these patients, two APOB genetic variants associated with lower LDL cholesterol were more frequent than in controls. Moreover, the LDL cholesterol gene score, calculated with 11 SNPs, was significantly lower in mutation-negative patients. CONCLUSIONS: Around half of the patients could be genetically diagnosed. The results suggest that, in at least some of the patients without an identified mutation, primary hypobetalipoproteinemia may have a polygenic origin.


Subject(s)
Angiopoietin-like Proteins/genetics , Apolipoproteins B/genetics , Carrier Proteins/genetics , DNA/genetics , Hypobetalipoproteinemia, Familial, Apolipoprotein B/genetics , Monomeric GTP-Binding Proteins/genetics , Mutation , Adolescent , Adult , Aged , Angiopoietin-Like Protein 3 , Angiopoietin-like Proteins/metabolism , Apolipoproteins B/metabolism , Carrier Proteins/metabolism , Child , Child, Preschool , DNA Mutational Analysis , Female , Genetic Markers , Heterozygote , Homozygote , Humans , Hypobetalipoproteinemia, Familial, Apolipoprotein B/diagnosis , Hypobetalipoproteinemia, Familial, Apolipoprotein B/metabolism , Infant , Male , Microsomes , Middle Aged , Monomeric GTP-Binding Proteins/metabolism , Phenotype , Young Adult
5.
Mater Sci Eng C Mater Biol Appl ; 78: 806-816, 2017 Sep 01.
Article in English | MEDLINE | ID: mdl-28576053

ABSTRACT

Antibacterial and biocompatible SnO2 nanorods have been easily synthesized through a hydrothermal process with the aid of a cationic surfactant, and incorporated as nanoreinforcements in poly(propylene fumarate-co-ethylene glycol) (P(PF-co-EG)) copolymer crosslinked with N-vinyl-pyrrolidone (NVP) by sonication and thermal curing. The nanorods were randomly and individually dispersed inside the P(PF-co-EG) network, and noticeably increased the thermal stability, hydrophilicity, degree of crystallinity, protein absorption capability as well as stiffness and strength of the matrix, whilst decreased its level of porosity and biodegradation rate. More importantly, the resulting nanocomposites retained adequate rigidity and strength after immersion in a simulated body fluid (SBF) at 37°C. They also exhibited biocide action against Gram-positive and Gram-negative bacteria; their antibacterial effect was strong under UV-light illumination whilst in dark conditions was only moderate. Further, they did not cause toxicity on human dermal fibroblasts. The friction coefficient and wear rate strongly decreased with increasing nanorod loading under both dry and SBF conditions; the greatest drops in SBF were about 18-fold and 13-fold, respectively, compared to those of the copolymer network. These novel biomaterials are good candidates to be applied in the field of soft-tissue engineering.


Subject(s)
Nanotubes , Anti-Bacterial Agents , Biocompatible Materials , Ethylene Glycol , Humans , Hydrogels , Polyethylene Glycols , Polypropylenes , Tin Compounds
6.
J Mater Chem B ; 5(22): 4084-4096, 2017 Jun 14.
Article in English | MEDLINE | ID: mdl-32264141

ABSTRACT

A novel biodegradable poly(glycolic acid-co-propylene fumarate) (PGA-co-PPF) copolymer has been synthesized via ring-opening polymerization. Graphene oxide (GO) and hydroxyapatite nanorods have been incorporated into PGA-co-PPF through electrospinning to yield hybrid nanocomposite fibers, and their morphology, water uptake, biodegradability, cytotoxicity, and mechanical, thermal and antibacterial properties have been analyzed. The addition of GO improved the dispersion of the HA nanorods within the matrix, and led to the formation of thinner fibers. The simultaneous incorporation of both nanofillers significantly increased the water absorption, biodegradation rate and protein adsorption capability of PGA-co-PPF. The hybrids induced higher osteoblast cell vitality and alkaline phosphatase activity than the neat copolymer and binary nanocomposites with either HA or GO, and showed higher biocidal activity against Gram-positive S. aureus and Gram-negative E. coli bacteria. Furthermore, experimental results revealed a synergistic effect of the nanofillers on improving the copolymer biocompatibility, thermal stability, stiffness, strength and toughness, and the nanocomposite with 20 wt% HA and 5 wt% GO exhibited the best combination of properties. The development of multifunctional polymer nanocomposite fibers with good biodegradability, very low toxicity, high tensile modulus and strong bactericidal activity opens up new perspectives for bone tissue engineering applications.

7.
ACS Appl Mater Interfaces ; 8(28): 17902-14, 2016 Jul 20.
Article in English | MEDLINE | ID: mdl-27383639

ABSTRACT

Poly(propylene fumarate) (PPF)-based nanocomposites incorporating different amounts of polyethylene glycol-functionalized graphene oxide (PEG-GO) have been prepared via sonication and thermal curing, and their surface morphology, structure, thermal stability, hydrophilicity, water absorption, biodegradation, cytotoxicity, mechanical, viscoelastic and antibacterial properties have been investigated. SEM and TEM images corroborated that the noncovalent functionalization with PEG caused the exfoliation of GO into thinner flakes. IR spectra suggested the presence of strong hydrogen-bonding interactions between the nanocomposite components. A gradual rise in the level of hydrophilicity, water uptake, biodegradation rate, surface roughness, protein absorption capability and thermal stability was found upon increasing GO concentration in the composites. Tensile tests revealed improved stiffness, strength and toughness for the composites compared to unfilled PPF, ascribed to a homogeneous GO dispersion within the matrix along with a strong PPF/PEG-GO interfacial adhesion via polar and hydrogen bonding interactions. Further, the nanocomposites retained enough stiffness and strength under a biological state to provide effective support for bone tissue formation. The antibacterial activity was investigated against Gram-positive Staphylococcus aureus and Staphylococcus epidermidis as well as Gram-negative Pseudomonas aeruginosa and Escherichia coli microorganisms, and it rose sharply upon increasing GO concentration; systematically, the biocide effect was stronger versus Gram-positive bacteria. Cell viability data demonstrated that PPF/PEG-GO composites do not induce toxicity over human dermal fibroblasts. These novel materials show great potential to be applied in the bone tissue engineering field.


Subject(s)
Fumarates/chemistry , Graphite/chemistry , Nanocomposites/chemistry , Oxides/chemistry , Polyethylene Glycols/chemistry , Polymers/chemistry , Propylene Glycols/chemistry , Tissue Engineering/instrumentation , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Biocompatible Materials/chemistry , Biocompatible Materials/pharmacology , Bone and Bones/cytology , Cell Growth Processes/physiology , Escherichia coli/drug effects , Fibroblasts/drug effects , Fumarates/pharmacology , Graphite/pharmacology , Humans , Oxides/pharmacology , Polyethylene Glycols/pharmacology , Polymers/pharmacology , Propylene Glycols/pharmacology , Pseudomonas aeruginosa/drug effects , Staphylococcus aureus/drug effects , Tissue Engineering/methods
8.
J Mater Chem B ; 4(4): 600-612, 2016 Jan 28.
Article in English | MEDLINE | ID: mdl-32262942

ABSTRACT

Chitosan-grafted polycaprolactone (CS-g-PCL)/poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) fiber blends were prepared via wet electrospinning, and their morphology, hydrophilicity, water absorption, biodegradation, cytotoxicity, and thermal, mechanical and antibacterial properties were analyzed. IR spectra revealed strong H-bonding interactions between CS-g-PCL and PHBHHx. SEM and DSC analysis confirmed the immiscibility of the blends at all compositions studied. As the proportion of CS-g-PCL increased, the overall crystallinity of the blends increased, the melting temperature of PCL decreased, and each component promoted the crystallization of the others. The hydrophilicity, water absorption and weight loss in buffered solution decreased as the PHBHHx content increased. DMA and tensile tests indicated a synergistic effect on the mechanical properties at a blend composition of 70/30, leading to an optimal combination of stiffness, strength, ductility and toughness. The fibers retained adequate rigidity and strength under physiological conditions. The 70/30 blend exhibited the highest biocide action against Gram-positive and Gram-negative bacteria. The fibers did not induce toxicity over human dermal fibroblasts. These biodegradable, biocompatible electrospun fibers could be used as scaffolds for tissue engineering.

9.
Biomacromolecules ; 16(9): 2631-44, 2015 Sep 14.
Article in English | MEDLINE | ID: mdl-26302315

ABSTRACT

Castor oil (CO), which is a readily available, relatively inexpensive, and environmentally benign nonedible oil, has been successfully used as matrix material to prepare biocompatible and biodegradable nanocomposite films filled with chitosan (CS)-modified ZnO nanoparticles. The biocomposites were synthesized via a simple and versatile solution mixing and casting method. The morphology, structure, thermal stability, water absorption, biodegradability, cytocompatibility, barrier, mechanical, viscoelastic, antibacterial, and wound healing properties of the films have been analyzed. FT-IR spectra were used to obtain information about the nanoparticle-matrix interactions. The thermal stability, hydrophilicity, degree of porosity, water absorption, water vapor transmission rate (WVTR), oxygen permeability (Dk), and biodegradability of the films increased with the CS-ZnO loading. The WVTR and Dk data obtained are within the range of values reported for commercial wound dressings. Tensile tests demonstrated that the nanocomposites displayed a good balance between elasticity, strength, and flexibility under both dry and simulated body fluid (SBF) environments. The flexibility increased in a moist atmosphere due to the plasticization effect of absorbed water. The nanocomposites also exhibited significantly enhanced dynamic mechanical performance (storage modulus and glass transition temperature) than neat CO under different humidity conditions. The antibacterial activity of the films against Escherichia coli, Staphylococcus aureus, and Micrococcus luteus bacteria was investigated in the presence and the absence of UV light. The biocide effect increased progressively with the CS-ZnO content and was systematically stronger against Gram-positive cells. Composites with nanoparticle loading ≤5.0 wt % exhibited very good in vitro cytocompatibility and enabled a faster wound healing than neat CO and control gauze, hence showing great potential to be applied as antibacterial wound dressings.


Subject(s)
Castor Oil/chemistry , Chitosan/chemistry , Dermis/metabolism , Fibroblasts/metabolism , Membranes, Artificial , Nanocomposites/chemistry , Nanoparticles/chemistry , Wound Healing , Zinc Oxide/chemistry , Anti-Bacterial Agents/chemistry , Bacteria/growth & development , Cell Survival , Dermis/pathology , Fibroblasts/pathology , Humans , Materials Testing
10.
ACS Appl Mater Interfaces ; 7(9): 5561-73, 2015 Mar 11.
Article in English | MEDLINE | ID: mdl-25706225

ABSTRACT

Biocompatible ternary nanocomposites based on poly(ether ether ketone) (PEEK)/poly(ether imide) (PEI) blends reinforced with bioactive titanium dioxide (TiO2) nanoparticles were fabricated via ultrasonication followed by melt-blending. The developed biomaterials were characterized using FT-IR, SEM, XRD, DSC, TGA, and DMA. Further, their water-absorption, tensile, tribological, dielectric, and antibacterial properties were evaluated. PEI acts as a coupling agent, since it can interact both with PEEK via π-π stacking and polar interactions as well as with the nanoparticles through hydrogen bonding, as corroborated by the FT-IR spectra, which resulted in a homogeneous titania dispersion within the biopolymer blend without applying any particle surface treatment or polymer functionalization. A change from promotion to retardation in the crystallization rate of the matrix was found with increasing TiO2 concentration, while its crystalline structure remained unaltered. The nanoparticles stiffened, strengthened, and toughened the matrix simultaneously, and the optimal properties were achieved at 4.0 wt % TiO2. More interesting, the tensile properties were retained after steam sterilization in an autoclave or exposure to a simulated body fluid (SBF). The nanocomposites also displayed reduced water absorption though higher thermal stability, storage modulus, glass transition temperature, dielectric constant, and dielectric loss compared to the control blend. Further, remarkable enhancements in the tribological properties under both SBF and dry environments were attained. The nanoparticles conferred antibacterial action versus Gram-positive and Gram-negative bacteria in the presence and the absence of UV light, and the highest inhibition was attained at 4.0 wt % nanoparticle concentration. These nanocomposites are expected to be used in long-term load-bearing implant applications.


Subject(s)
Biocompatible Materials/chemistry , Ketones/chemistry , Metal Nanoparticles/chemistry , Polyethylene Glycols/chemistry , Polymers/chemistry , Titanium/chemistry , Benzophenones , Biocompatible Materials/pharmacology , Calorimetry, Differential Scanning , Elastic Modulus , Gram-Negative Bacteria/drug effects , Gram-Negative Bacteria/radiation effects , Gram-Positive Bacteria/drug effects , Gram-Positive Bacteria/radiation effects , Humans , Metal Nanoparticles/toxicity , Prostheses and Implants , Temperature , Ultraviolet Rays , Water/chemistry
11.
J Mater Chem B ; 3(21): 4458-4471, 2015 Jun 07.
Article in English | MEDLINE | ID: mdl-32262790

ABSTRACT

This study deals with the preparation and characterization of acrylated epoxidized linseed oil (AELO) based bionanocomposites for antimicrobial coating applications. AELO was synthesized from epoxidized vegetable oils, crosslinked with an acrylic monomer, reinforced with anatase TiO2 nanoparticles and then subjected to UV irradiation to yield the cured nanocomposite coatings. The effect of TiO2 loading on the morphology, barrier, thermal, mechanical, tribological and antibacterial performance of the coatings has been comprehensively investigated. FT-IR spectra indicated the existence of strong TiO2-AELO hydrogen bonding interactions. The nanoparticles were randomly dispersed within the bioresin, significantly reducing its water absorption and gas permeability whilst increasing its thermal stability. They also promoted remarkable enhancements of both static and dynamic mechanical properties such as storage and Young's moduli, hardness, impact resistance and glass transition temperature. Strong reductions in the coefficient of friction and the wear rate were attained in the nanocomposites with the highest TiO2 loadings. The coatings were found to display antimicrobial activity even in the absence of UV light, and the bactericidal effect against Staphylococcus aureus was higher than on Escherichia coli. Furthermore, the antimicrobial activity improved with increasing nanoparticle concentration. The use of these "green" nanocomposite coatings could be a suitable and inexpensive method to prevent microbial proliferation in public places, particularly in medical centers where there is higher risk of infections.

12.
ACS Appl Mater Interfaces ; 6(19): 17277-88, 2014 Oct 08.
Article in English | MEDLINE | ID: mdl-25222018

ABSTRACT

Biocompatible and biodegradable nanocomposites comprising epoxidized soybean oil (ESO) as matrix, zinc oxide (ZnO) nanoparticles as reinforcements, and 4-dimethylaminopyridine (DMAP) as a catalyst have been successfully prepared via epoxidization of the double bonds of the vegetable oil, ultrasonication, and curing without the need for interfacial modifiers. Their morphology, water uptake, thermal, mechanical, barrier, tribological, and antibacterial properties have been investigated. FT-IR analysis revealed the existence of strong ESO-ZnO hydrogen-bonding interactions. The nanoparticles acted as mass transport barriers, hindering the diffusion of volatiles generated during the decomposition process and leading to higher thermal stability, and also reduced the water absorption and gas permeability of the bioresin. Significant improvements in the static and dynamic mechanical properties, such as storage and Young's moduli, tensile strength, toughness, hardness, glass transition, and heat distortion temperature, were attained on reinforcement. A small drop in the nanocomposite stiffness and strength was found after exposure to several cycles of steam sterilization or to simulated body fluid (SBF) at physiological temperature. Extraordinary reductions in the coefficient of friction and wear rate were detected under both dry and SBF conditions, confirming the potential of these nanoparticles for improving the tribological performance of ESO. The nanocomposites displayed antimicrobial action against human pathogen bacteria with and without UV illumination, which increased progressively with the ZnO content. These sustainable, ecofriendly, and low-cost biomaterials are very promising for use in biomedical applications, like structural tissue engineering scaffolds.


Subject(s)
Materials Testing/methods , Nanocomposites/chemistry , Soybean Oil/chemistry , Soybean Oil/chemical synthesis , Zinc Oxide/chemistry , Anti-Bacterial Agents/pharmacology , Escherichia coli/drug effects , Hardness , Humans , Microbial Sensitivity Tests , Nanocomposites/ultrastructure , Spectroscopy, Fourier Transform Infrared , Staphylococcus aureus/drug effects , Temperature , Tensile Strength , Thermogravimetry , Water/chemistry
13.
Int J Mol Sci ; 15(6): 10950-73, 2014 Jun 17.
Article in English | MEDLINE | ID: mdl-24941255

ABSTRACT

Poly(3-hydroxybutyrate) (PHB)-based bionanocomposites incorporating different contents of ZnO nanoparticles were prepared via solution casting technique. The nanoparticles were dispersed within the biopolymer without the need for surfactants or coupling agents. The morphology, thermal, mechanical, barrier, migration and antibacterial properties of the nanocomposites were investigated. The nanoparticles acted as nucleating agents, increasing the crystallization temperature and the degree of crystallinity of the matrix, and as mass transport barriers, hindering the diffusion of volatiles generated during the decomposition process, leading to higher thermal stability. The Young's modulus, tensile and impact strength of the biopolymer were enhanced by up to 43%, 32% and 26%, respectively, due to the strong matrix-nanofiller interfacial adhesion attained via hydrogen bonding interactions, as revealed by the FT-IR spectra. Moreover, the nanocomposites exhibited reduced water uptake and superior gas and vapour barrier properties compared to neat PHB. They also showed antibacterial activity against both Gram-positive and Gram-negative bacteria, which was progressively improved upon increasing ZnO concentration. The migration levels of PHB/ZnO composites in both non-polar and polar simulants decreased with increasing nanoparticle content, and were well below the current legislative limits for food packaging materials. These biodegradable nanocomposites show great potential as an alternative to synthetic plastic packaging materials especially for use in food and beverage containers and disposable applications.


Subject(s)
Anti-Bacterial Agents/chemistry , Hydroxybutyrates/chemistry , Nanocomposites/chemistry , Polyesters/chemistry , Zinc Oxide/chemistry , Anti-Bacterial Agents/pharmacology , Crystallization , Elastic Modulus , Food Packaging , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , Nanocomposites/toxicity , Nanocomposites/ultrastructure , Phase Transition , Temperature , Tensile Strength
14.
ACS Appl Mater Interfaces ; 6(13): 10132-45, 2014 Jul 09.
Article in English | MEDLINE | ID: mdl-24926534

ABSTRACT

An aminated poly(phenylene sulfide) derivative (PPS-NH2) has been melt-blended with different contents of ZnO nanoparticles, and the morphology, thermal, mechanical, tribological, antibacterial, and dielectric properties of the resulting nanocomposites have been investigated. The nanoparticles were dispersed within the matrix without the need for surfactants or coupling agents. A gradual rise in the crystallization temperature and the degree of crystallinity was found with increasing ZnO loading, confirming that the nanoparticles act as nucleating agents for PPS-NH2 crystallization. The nanoparticles reduced the water absorption and strongly increased the thermal stability of the matrix, leading to an extraordinary increase in the initial degradation temperature of 80 °C at 8.0 wt % nanoparticle content. The results showed that the stiffness, strength, toughness, glass transition, and heat distortion temperature were remarkably enhanced, whereas the coefficient of thermal expansion decreased upon addition of ZnO, ascribed to strong hydrogen bonding interactions between the amino groups of the matrix and the hydroxyl moieties of the nanoparticles. Moreover, the nanocomposites retained the tensile properties after being exposed to several cycles of steam sterilization. More importantly, an unprecedented drop in wear rate of nearly 100-fold was attained in the nanocomposite with the highest loading, demonstrating the suitability of these nanoparticles for providing wear resistance to the matrix. All the nanocomposites displayed low dielectric constant and dielectric loss, hence can be employed as insulating materials in electrosurgical applications. They also exhibited active inhibition against both Gram-positive and Gram-negative bacteria, which was gradually enhanced with increasing ZnO content. These nanocomposites are suitable as lightweight high-performance materials in the field of medicine and dentistry.


Subject(s)
Nanocomposites/chemistry , Polymers/chemistry , Zinc Oxide/chemistry , Calorimetry, Differential Scanning , Crystallization , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission , Spectroscopy, Fourier Transform Infrared
15.
ACS Appl Mater Interfaces ; 6(12): 9822-34, 2014 Jun 25.
Article in English | MEDLINE | ID: mdl-24846876

ABSTRACT

Biodegradable nanocomposites were prepared by adding ZnO nanoparticles to bacterial polyester poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) via solution casting technique. The morphology, thermal, mechanical, antibacterial, barrier, and migration properties of the nanocomposites were analyzed. The nanoparticles were uniformly dispersed within PHBV without the aid of coupling agents, and acted effectively as nucleating agents, raising the crystallization temperature and the level of crystallinity of the matrix while decreasing its crystallite size. A gradual rise in thermal stability was found with increasing ZnO loading, since the nanofillers hinder the diffusion of volatiles generated during the decomposition process. The nanocomposites displayed superior stiffness, strength, toughness, and glass transition temperature, whereas they displayed reduced water uptake and oxygen and water vapor permeability compared to the neat biopolymer, related to the strong matrix-nanofiller interfacial adhesion attained via hydrogen bonding interactions. At an optimal concentration of 4.0 wt % ZnO, the tensile strength and Young's and storage moduli showed a maximum that coincided with the highest crystallinity and the best barrier properties. PHBV/ZnO films showed antibacterial activity against human pathogen bacteria, and the effect on Escherichia coli was stronger than on Staphylococcus aureus. The overall migration levels of the nanocomposites in both nonpolar and polar simulants dropped upon increasing nanoparticle content, and were well below the limits required by the current normative for food packaging materials. These sustainable nanomaterials with antimicrobial function are very promising to be used as containers for beverage and food products as well as for disposable applications like cutlery or overwrap films.


Subject(s)
3-Hydroxybutyric Acid/chemistry , Anti-Infective Agents/chemistry , Food Packaging , Pentanoic Acids/chemistry , Zinc Oxide/chemistry , Humans , Nanocomposites/chemistry , Polyesters/chemistry , Staphylococcus aureus/drug effects , Water/chemistry
16.
J Diabetes Sci Technol ; 8(5): 1005-10, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24876454

ABSTRACT

Background. Continuous subcutaneous insulin infusion (CSII) is an established modality for intensive insulin treatment of type 1 diabetes (T1D), but long-term data concerning satisfaction, CSII function use, safety, and efficacy in real-life conditions are scarce. Methods. We analyzed a cohort of adult patients with T1D treated with CSII for more than 1 year in a single diabetes center. We performed a cross-sectional survey in 2010 (tolerance/satisfaction and behavior forms) and a retrospective analysis of medical records (including HbA1c level, hospitalization, and catheter infections). The primary objective was to assess long-term tolerance/satisfaction, and secondary objectives were safety and efficacy. Results. There were 295 patients analyzed. After a median duration of CSII use of 5 years, overall satisfaction was high for about 90% of patients. Mean CSII-related discomfort scores were low for work, recreation, and sleep and moderate for sport and sexual activity (2.5 ± 1.9, 2.6 ± 1.8, 2.6 ± 2.1, 3.4 ± 2.3, and 4.0 ± 2.9 of 10, respectively). Despite a high level of diabetes education, only one third of patients were using advanced CSII functions. During long-term follow-up, the safety of CSII treatment was good; the hospitalization rate was 0.18 patients/year, and catheter infections were scarce. The HbA1c level dropped about -0.5% independently from CSII duration (P < .05). Conclusions. In this adult cohort, satisfaction and tolerance, together with safety, of CSII were maintained at long-term follow up. The sole basic functions of CSII were currently used by patients. A 0.5% decrease in the HbA1c level was maintained during the study period.


Subject(s)
Blood Glucose/analysis , Diabetes Mellitus, Type 1/blood , Diabetes Mellitus, Type 1/drug therapy , Insulin Infusion Systems , Adult , Cohort Studies , Cross-Sectional Studies , Female , Glycated Hemoglobin/analysis , Humans , Hypoglycemic Agents/administration & dosage , Insulin/administration & dosage , Insulin Infusion Systems/adverse effects , Male , Patient Satisfaction , Retrospective Studies
17.
ACS Appl Mater Interfaces ; 6(5): 3729-41, 2014 Mar 12.
Article in English | MEDLINE | ID: mdl-24552261

ABSTRACT

Novel poly(ether ether ketone) (PEEK) based nanocomposites have been fabricated via melt-blending by addition of a carboxylated polymer derivative covalently grafted onto the surface of hydroxyl-terminated ZnO nanoparticles. Their morphology, thermal, mechanical, tribological, and antibacterial properties have been analyzed and compared with those of composites reinforced with pristine ZnO. The Fourier transform infrared (FT-IR) spectra corroborate the success of the grafting reaction, showing the appearance of signals related to ester linkages. Microscopic observations demonstrate that the polymer grafting improves the nanoparticle dispersion within the matrix. A progressive rise in thermal stability and flame retardant ability is found with increasing ZnO concentration, with an exceptional increment in the maximum degradation rate temperature of 70 °C at 5.0 wt % loading. The crystallization and melting temperature of PEEK decrease upon incorporation of the grafted nanofillers, attributed to the restrictions on polymer chain mobility and crystal growth imposed by the strong ZnO-matrix interactions. Nanocomposites with polymer-grafted nanoparticles exhibit higher stiffness, strength, ductility, toughness and glass transition temperature whilst lower coefficient of friction and wear rate than the neat polymer and composites with bare ZnO. Further, they show superior antibacterial activity against both the Gram-negative Escherichia coli and the Gram-positive Staphylococcus aureus bacteria. The antimicrobial effect increases upon raising nanoparticle content, and is stronger on E. coli. The approach used in this work is a simple, scalable, and efficient method to improve the performance of PEEK/ZnO nanocomposites for use in biomedical applications such as trauma, orthopedics, and spinal implants.


Subject(s)
Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Ketones/chemistry , Nanocomposites/chemistry , Polyethylene Glycols/chemistry , Zinc Oxide/pharmacology , Bacteria/drug effects , Benzophenones , Drug Carriers/chemistry , Polymers , Zinc Oxide/chemistry
18.
J Mater Chem B ; 2(43): 7502-7514, 2014 Nov 21.
Article in English | MEDLINE | ID: mdl-32261889

ABSTRACT

Nanocomposites of biocompatible polyphenylsulfone (PPSU) and titanium dioxide (TiO2) nanoparticles have been prepared via ultrasonication and solution casting. Their structure, surface morphology, water uptake, thermal, mechanical, tribological and antibacterial properties have been investigated in detail. FT-IR analysis revealed the existence of strong hydrogen bonding interactions between the sulfone group of PPSU and the hydroxyl moieties of the nanoparticles, which were homogenously dispersed within the matrix without adding coupling agents. The incorporation of TiO2 reduced the water absorption and increased the thermal stability of the polymer under both inert and oxidative conditions. Furthermore, the nanocomposites exhibited greatly enhanced mechanical performance (storage and Young's moduli, tensile strength and toughness, glass transition and heat distortion temperature) compared to neat PPSU, confirming the formation of a strong nanofiller-matrix interface necessary for an efficient load transfer. Moreover, their tensile properties were retained after exposure to several cycles of steam sterilization or to simulated body fluid (SBF) at physiological temperature. Outstanding improvements in the tribological performance under both dry and SBF conditions were also attained, demonstrating the suitability of these nanoparticles for providing wear resistance to the matrix. The nanocomposites exhibited inhibition against both Gram-positive and Gram-negative bacteria with and without UV illumination, which was progressively enhanced with increasing TiO2 loading. These biomaterials are very promising for use in biomedical applications like orthopaedic and trauma implants.

19.
Arch Ital Urol Androl ; 85(3): 149-53, 2013 Sep 26.
Article in English | MEDLINE | ID: mdl-24085238

ABSTRACT

OBJECTIVES: To analyze the short and long term results of tapes of different materials used to treat stress urinary incontinence (SUI). A secondary objective was to evaluate the ability to adjust the tape after implantation. MATERIALS AND METHODS: Retrospective chart review of 355 patients with SUI operated between March 2003 and October 2011. Eight different types of transobturator tapes were used: Gynecare TVT-O®, Monarc®, SAFYRE®, Contasure KIM®, I-Stop®, DynaMesh®, Aris® Bandellete and Swing-band®. Results and complications were recorded. RESULTS: The mean age at operation was 61 years. Correction of SUI was achieved in 87.88% of cases. The best results were obtained with Contasure KIM® (98.26 % continence). The tape was well tolerated and was elastic enough to be able to be adjusted 48-72 hours after implantation without deformation. Slings with macropores and over lock stitches on the superior and inferior borders presented the lower rates of postoperative urinary retention, pain, perior postoperative bleeding and urinary tract infections. CONCLUSIONS: Transobturator tension free tapes require a short operation time and have a low complication rate. The possibility of adjustment in the early postoperative period increases the success rate and reduces complications. Knotless meshes with macropores and over lock stitches appear to be better balanced, are quite resistant to stretching and deformation when readjusted after implantation and present a low infection rate.


Subject(s)
Suburethral Slings , Urinary Incontinence, Stress/surgery , Adult , Aged , Aged, 80 and over , Female , Humans , Middle Aged , Prosthesis Design , Retrospective Studies
20.
Crim Behav Ment Health ; 21(5): 321-32, 2011 Dec.
Article in English | MEDLINE | ID: mdl-21706528

ABSTRACT

BACKGROUND: The prevalence of mental disorders among prisoners has been researched in a few countries worldwide but never previously in Spain. AIM: Our aim was to estimate the lifetime and last month prevalence of mental disorders in a Spanish prison population. METHODS: This is a descriptive, cross-sectional, epidemiological study of 707 male prisoners. Sociodemographic, clinical and offending data were collected by interviewers. Offending data were confirmed using penitentiary records. Mental disorders were assessed with the clinical version of the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition Axis I Disorders, and personality disorders were assessed through the Spanish version of the International Personality Disorders Examination. RESULTS: The lifetime prevalence of mental disorder was 84.4%. Substance use disorder (abuse and dependence) was the most frequent disorder (76.2%) followed by anxiety disorder (45.3%), mood disorder (41%) and psychotic disorder (10.7%). The period (last month) prevalence of any mental disorder was 41.2%. Anxiety disorder was the most prevalent (23.3%) followed by substance use disorder (abuse and dependence; 17.5%), mood disorder (14.9%) and psychotic disorder (4.2%). CONCLUSION: Although period prevalence figures, which are those generally provided in research into rates of mental disorder among prisoners, are useful for planning improvements to services within prisons, the fact that almost all of these men had a lifetime prevalence of at least one mental disorder suggests a much wider need for improving services, including community services, for this group.


Subject(s)
Mental Disorders/epidemiology , Prisoners/psychology , Adolescent , Adult , Aged , Cohort Studies , Criminal Psychology , Cross-Sectional Studies , Humans , Male , Mental Disorders/classification , Middle Aged , Prevalence , Prisons , Spain/epidemiology , Young Adult
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