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1.
Langmuir ; 31(35): 9718-27, 2015 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-26038977

RESUMEN

We have developed a potentiostatic double-pulse technique for silver nanoparticle (Ag NP) deposition on graphene (GRn) with superior electronic and ionic conductivity. This approach yielded a two-dimensional electrocatalyst with a homogeneous Ag NP spatial distribution having remarkable performance in the oxygen reduction reaction (ORR). GRn sheets were reproducibly prepared by the electrochemical exfoliation of graphite (GRp) at high yield and purity with a low degree of oxidation. Polystyrenesulfonate added during exfoliation enhanced the stability of the GRn solution by preventing the restacking of the graphene sheets and increased its ionic conductivity. The potentiostatic double-pulse technique is generally used to electrodeposit Pt nanoparticles and remains challenging for silver metal that exhibits nucleation and growth potentials relatively close to each other. We judiciously exploited this narrow margin of potential, and for the first time we report Ag NP electrodeposited onto graphene with the subsequent ability to control both the density and the size of metallic nanoparticles. Considering the high activity along with the lower cost of Ag compared to Pt, these findings are highly relevant to the successful commercialization of fuel cells and other electrochemical energy devices.


Asunto(s)
Técnicas Electroquímicas , Grafito/química , Nanopartículas del Metal/química , Oxígeno/química , Plata/química , Catálisis , Oxidación-Reducción , Tamaño de la Partícula , Propiedades de Superficie
2.
Langmuir ; 30(23): 6915-9, 2014 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-24856780

RESUMEN

Biomimetic carbonation carried out with carbonic anhydrase (CA) in CO2-absorbing solutions, such as methyldiethanolamine (MDEA), is one approach that has been developed to accelerate the capture of CO2. However, there are several practical issues, such as high cost and limited enzyme stability, that need to be overcome. In this study, the capacity of CA immobilization on a porous solid support was studied to improve the instability in the tertiary amine solvent. We have shown that a 63% porosity macroporous carbon foam support makes separation and reuse facile and allows for an efficient supply and presentation of CO2 to an aqueous solvent and the enzyme catalytic center. These enzymatic supports conserved 40% of their initial activity after 42 days at 70 °C in an amine solvent, whereas the free enzyme shows no activity after 1 h in the same conditions. In this work, we have overcome the technical barrier associated with the recovery of the biocatalyst after operation, and most of all, these electropolymerized enzymatic supports have shown a remarkable increase of thermal stability in an amine-based CO2 sequestration solvent.


Asunto(s)
Dióxido de Carbono/química , Anhidrasas Carbónicas/química , Anhidrasas Carbónicas/metabolismo , Enzimas Inmovilizadas/química , Etanolaminas/química
3.
Discov Mater ; 4(1): 19, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38938324

RESUMEN

The development of efficient, low-cost water splitting electrocatalysts is needed to store energy by generating sustainable hydrogen from low power clean but intermittent energy sources such as solar and wind. Here, we report a highly sustained low overpotential for oxygen evolution reached by the unique combination of three metals (NiCoV) prepared from a simple low temperature auto-combustion process. The amorphous multimetal oxygen evolving catalyst could be stably coated on a stainless-steel support using a tribochemical particle blasting method to create an oxygen evolution reaction (OER) electrode with a low overpotential of 230 mV at 10 mA cm-2 and a low Tafel slope of 40 mV dec-1. In addition to their low overpotential, this oxygen evolving electrocatalyst preserved performance demonstrating a stability after 10 h at the technologically relevant current density and without any surface morphology alteration. Given the importance of sustainable hydrogen production, the development of this new OER catalyst points the way to removing a key technical bottleneck for the water splitting reaction and could offer a route to cost reduction and lowering hurdles to more widespread adaptation of electrolyser technologies for hydrogen production. Supplementary Information: The online version contains supplementary material available at 10.1007/s43939-024-00087-5.

4.
Orthop Traumatol Surg Res ; : 103834, 2024 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-38340961

RESUMEN

BACKGROUND: Opinions differ on the optimal treatment for stable talar osteochondritis dissecans (OCD) with intact cartilage. Some recommend conservative management, while others prefer surgical care, which includes debridement and micro-fractures, transarticular drilling through a direct or medial malleolus approach and retroarticular drilling. The rationale behind retroarticular drilling is to induce bone marrow healing without touching the intact cartilage. The goal of this systematic review is to summarize the clinical outcomes of retroarticular drilling as a standalone procedure for stable talar OCD with intact cartilage. PATIENTS AND METHODS: A systematic review of the literature prospectively registered in the PROSPERO register was performed along the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Medline, EMBASE and Evidence-Based Medicine databases were searched from inception to December 2021 for retroarticular drilling for stable talar OCD with an intact cartilage. Two independent evaluators screened the search results, selected the articles to be included in the analysis and assessed the methodological quality of all included articles with the Newcastle-Ottawa Scale (NOS). RESULTS: Twelve studies, on 99 patients were included in the final analysis. Methodological quality was poor for all the included studies. High heterogeneity prevented any pooling or meta-analysis, but favorable clinical results were reported according to excellent post-intervention scores on the American Orthopedic Foot and Anke Score (AOFAS), ranging from 88.9 to 100. There was also significant improvement in pain as measured by the Visual Analog Scale (VAS), ranging between 2.3 and 5.9. DISCUSSION: Favorable results seem to be achieved with retroarticular drilling without grafting for stable talar OCD with intact cartilage, but more powered comparative studies between surgical options and conservative management are needed to establish the gold standard treatment. LEVEL OF EVIDENCE: IV.

5.
Biomedicines ; 12(9)2024 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-39335558

RESUMEN

Applying cold to a bone injury can aid healing, though its mechanisms are complex. This study investigates how cold therapy impacts bone repair to optimize healing. Cold was applied to a rodent bone model, with the physiological responses analyzed. Vasoconstriction was mediated by an increase in the transient receptor protein channels (TRPs), transient receptor potential ankyrin 1 (TRPA1; p = 0.012), and transient receptor potential melastatin 8 (TRPM8; p < 0.001), within cortical defects, enhancing the sensory response and blood flow regulation. Cold exposure also elevated hypoxia (p < 0.01) and vascular endothelial growth factor expression (VEGF; p < 0.001), promoting angiogenesis, vital for bone regeneration. The increased expression of osteogenic proteins peroxisome proliferator-activated receptor gamma coactivator (PGC-1α; p = 0.039) and RNA-binding motif protein 3 (RBM3; p < 0.008) suggests that the reparative processes have been stimulated. Enhanced osteoblast differentiation and the presence of alkaline phosphatase (ALP) at day 5 (three-fold, p = 0.021) and 10 (two-fold, p < 0.001) were observed, along with increased osteocalcin (OCN) at day 10 (two-fold, p = 0.019), indicating the presence of mature osteoblasts capable of mineralization. These findings highlight cold therapy's multifaceted effects on bone repair, offering insights for therapeutic strategies.

6.
J Biomed Mater Res A ; 112(10): 1817-1826, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-38689450

RESUMEN

Engineering cardiac implants for treating myocardial infarction (MI) has advanced, but challenges persist in mimicking the structural properties and variability of cardiac tissues using traditional bioconstructs and conventional engineering methods. This study introduces a synthetic patch with a bioactive surface designed to swiftly restore functionality to the damaged myocardium. The patch combines a composite, soft, and conductive hydrogel-based on (3,4-ethylenedioxythiophene):polystyrene-sulfonate (PEDOT:PSS) and polyvinyl alcohol (PVA). This cardiac patch exhibits a reasonably high electrical conductivity (40 S/cm) and a stretchability up to 50% of its original length. Our findings reveal its resilience to 10% cyclic stretching at 1 Hz with no loss of conductivity over time. To mediate a strong cell-scaffold adhesion, we biofunctionalize the hydrogel with a N-cadherin mimic peptide, providing the cardiac patch with a bioactive surface. This modification promote increased adherence and proliferation of cardiac fibroblasts (CFbs) while effectively mitigating the formation of bacterial biofilm, particularly against Staphylococcus aureus, a common pathogen responsible for surgical site infections (SSIs). Our study demonstrates the successful development of a structurally validated cardiac patch possessing the desired mechanical, electrical, and biofunctional attributes for effective cardiac recovery. Consequently, this research holds significant promise in alleviating the burden imposed by myocardial infarctions.


Asunto(s)
Conductividad Eléctrica , Hidrogeles , Poliestirenos , Hidrogeles/química , Hidrogeles/farmacología , Poliestirenos/química , Animales , Polímeros/química , Fibroblastos/efectos de los fármacos , Fibroblastos/citología , Compuestos Bicíclicos Heterocíclicos con Puentes/química , Compuestos Bicíclicos Heterocíclicos con Puentes/farmacología , Miocardio/metabolismo , Miocardio/citología , Materiales Biocompatibles/química , Adhesión Celular/efectos de los fármacos , Alcohol Polivinílico/química
7.
Tissue Eng Part A ; 2024 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-39041619

RESUMEN

Fracture healing, a critical and complex biological process, often presents challenges in clinical practice with the current standards failing to fully address the medical needs for rapid and effective recovery. In this work, a localized cold therapy is investigated as an alternative approach to expedite bone healing. We hypothesized that optimized cold application can enhance bone healing within a fracture model by inducing hypoxia, leading to accelerated angiogenesis along with improved osteogenesis. A short, localized cold exposure is directly applied to the fracture site over a 4-week period in a mouse fracture model, aiming to assess its impact on bone formation through mechanisms of angiogenesis and osteogenesis. Our results revealed a significantly greater volume of new bone tissue and enhanced vascularity at the fracture site in the cold-treated group compared with controls. Calcified tissue histology analysis showed that the accelerated callus maturation and development of the vascular network following cold exposure were associated with an activity increase of alkaline phosphatase and transient receptor potential vanilloid 1. These biological changes were accompanied by a hypoxic environment induced during cold therapy. The study provides compelling evidence supporting the efficacy of intermittent cold therapy in accelerating fracture healing. These promising results highlight the need for further research in larger-scale studies and diverse fracture models, underlining the potential of cold therapy as a novel, noninvasive treatment strategy in orthopedic care.

8.
J Orthop Trauma ; 37(3): e122-e127, 2023 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-36219778

RESUMEN

OBJECTIVES: Acute compartment syndrome is a devastating condition associated with lasting consequences or even death if not treated in a timely fashion. Current preclinical modeling is inadequate. Ideally a model should mimic human disease. There should be a trauma-induced reperfusion or direct muscle event that causes gradual increased pressure and is amenable to release with fasciotomy. We have attempted to reproduce this mechanism and outcome in a porcine model. METHODS: Anterior tibial musculature was injured with vascular occlusion plus exterior tourniquet crush or direct intracompartmental crush through balloon inflation. The injury was maintained for over 5 hours. At that time, the tourniquet or balloon was removed. The injuries were continuously monitored with an intramuscular continuous pressure sensor. Pressure changes were recorded and after 2 hours of postinjury observation, a fasciotomy was performed for the muscle compartment. RESULTS: Pressures were brought to 100 mm Hg during the injury phase. During the two-hour observation period, the balloon catheter technique achieved an average pressure of 25.1 ± SD 8.8 mm Hg with a maximum reading of 38.2 mm Hg and minimum reading of 14.1 mm Hg. During this same period, the ischemia-reperfusion + direct crush technique achieved an average pressure of 33.7 ± SD 7.3 mm Hg, with a maximum reading of 43.5 mm Hg and minimum reading of 23.5 mm Hg. Average pressure postfasciotomy for the balloon catheter technique was 2.4 ± SD 2.5 mm Hg; and for the crush technique, average value postfasciotomy was 4.9 ± SD 3.7 mm Hg-both representing a return to physiologic levels. CONCLUSION: This is the first preclinical model that shows the same response to injury and treatment as is observed in human physiology. Surgical and nonsurgical therapies for compartment syndrome can now be tested reliably.


Asunto(s)
Síndromes Compartimentales , Humanos , Animales , Porcinos , Síndromes Compartimentales/etiología , Síndromes Compartimentales/cirugía , Fasciotomía , Tibia , Presión
9.
Biomater Adv ; 153: 213519, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37392519

RESUMEN

Inadequate tissue blood supply as may be found in a wound or a poorly vascularised graft, can result in tissue ischemia and necrosis. As revascularization is a slow process relative to the proliferation of bacteria and the onset of tissue necrosis, extensive tissue damage and loss can occur before healing is underway. Necrosis can develop rapidly, and treatment options are limited such that loss of tissue following necrosis onset is considered unavoidable and irreversible. Oxygen delivery from biomaterials exploiting aqueous decomposition of peroxy-compounds has shown some potential in overcoming the supply limitations by creating oxygen concentration gradients higher than can be attained physiologically or by air saturated solutions. We sought to test whether subdermal oxygen delivery from a material composite that was buffered and contained a catalyst, to reduce hydrogen peroxide release, could ameliorate necrosis in a 9 × 2 cm flap in a rat model that reliably underwent 40 % necrosis if untreated. Blood flow in this flap reduced from near normal to essentially zero, along its 9 cm length and subdermal perforator vessel anastomosis was physically prevented by placement of a polymer sheet. In the middle, low blood flow region of the flap, treatment significantly reduced necrosis based on measurements from photographs and histological micrographs. No change was observed in blood vessel density but significant differences in HIF1-α, inducible nitric oxide synthase and liver arginase were observed with oxygen delivery.


Asunto(s)
Piel , Colgajos Quirúrgicos , Ratas , Animales , Piel/irrigación sanguínea , Piel/patología , Colgajos Quirúrgicos/irrigación sanguínea , Colgajos Quirúrgicos/patología , Isquemia/patología , Isquemia/prevención & control , Oxígeno/uso terapéutico , Necrosis/patología
10.
ACS Appl Mater Interfaces ; 14(17): 19285-19294, 2022 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-35452228

RESUMEN

This study examines the atomic confinement of commercial Pt/C electrocatalysts. While a high electrocatalytic activity for the oxygen reduction reaction is important for proton-exchange membrane fuel cell (PEMFC) performance, the high stability of the electrocatalyst is essential for real applications under harsh operating conditions. The demands necessitate the development of advanced electrocatalysts that are resistant to corrosion. A combination of diazonium chemistry with Cu electrodeposition permits the selective protection of the carbon surface of the commercial Pt/C to prevent corrosion while improving wettability and ionic transfer. The resulting electrocatalysts exhibit an exceptional ORR stability after accelerated stress testing (AST) with a 250% improvement in comparison with unprotected commercial Pt/C. This novel electrochemical pathway provides a much-needed boost to carbon-based catalytic supports, which still face several stability challenges in energy applications in a harsh environment.

11.
OTA Int ; 5(2 Suppl): e189, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35949264

RESUMEN

Digital health principles are starting to be evident in medicine. Orthopaedic trauma surgery is also being impacted -indirectly by all other improvements in the health ecosystem but also in particular efforts aimed at trauma surgery. Data acquisition is changing how evidence is gathered and utilized. Sensors are the pen and paper of the next wave of data acquisition. Sensors are gathering wide arrays of information to facilitate digital health relevance and adoption. Early adaption of sensor technology by the nonlegacy health environment is what has made sensor driven data acquisition so palatable to the normal health care system. As it applies to orthopaedic trauma, current sensor driven diagnostics and surveillance are nowhere near as developed as in the larger medical community. Digital health is being explored for health care records, data acquisition in diagnostics and rehabilitation, wellness to health care translation, intraoperative monitoring, surgical technique improvement, as well as some early-stage projects in long-term monitoring with implantable devices. The internet of things is the next digital wave that will undoubtedly affect medicine and orthopaedics. Internet of things (loT) devices are now being used to enable remote health monitoring and emergency notification systems. This article reviews current and future concepts in digital health that will impact trauma care.

12.
Nanomaterials (Basel) ; 12(24)2022 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-36558285

RESUMEN

Recently, the abnormal level of zinc emerged as a powerful indicator or risk factor for metabolic, endocrine, neurodegenerative and cardiovascular diseases, including cancer. Electrochemical detection has been explored to quantify zinc in a precise, rapid, and non-expensive way; however, most of the current electrochemical systems lack in specificity. In this work we studied a highly selective and sensitive electrochemical method to detect quickly and reliably free zinc ions (Zn2+). The surface of the working electrode was modified with zincon electropolymerized on carbon nanotube (CNT) to enable the binding of zinc in complex body fluids. After being physicochemically characterized, the performances of the zincon-CNT complex was electrochemically assessed. Square Wave Voltammetry (SWV) was used to determine the calibration curve and the linear range of zinc quantification in artificial saliva and urine. This zincon- CNT system could specifically quantify mobile Zn2+ in salivary and urinary matrices with a sensitivity of ~100 ng·mL-1 and a limit of detection (LOD) of ~20 ng·mL-1. Zincon-modified CNT presented as a desirable candidate for the detection and quantification of free zinc in easily body fluids that potentially can become a diagnostic non-invasive testing platform.

13.
Injury ; 53 Suppl 3: S59-S63, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36182592

RESUMEN

Medicine in general is quickly transitioning to a digital presence. Orthopaedic surgery is also being impacted by the tenets of digital health but there are also direct efforts with trauma surgery. Sensors are the pen and paper of the next wave of data acquisition. Orthopaedic trauma can and will be part of this new wave of medicine. Early sensor products that are now coming to market, or are in early development, will directly change the way we think about surgical diagnosis and outcomes. Sensor development for biometrics is already here. Wellness devices, pressure, temperature, and other parameters are already being measured. Data acquisition and analysis is going to be a fruitful addition to our research armamentarium with the volume of information now available. A combination of broadband internet, micro electrical machine systems (MEMS), and new wireless communication standards is driving this new wave of medicine. The Internet of Things (IoT) [1] now has a subset which is the Internet of Medical Devices [2-5] permitting a much more in-depth dive into patient procedures and outcomes. IoT devices are now being used to enable remote health monitoring, in hospital treatment, and guide therapies. This article reviews current sensor technology that looks to impact trauma care.


Asunto(s)
Tecnología , Tecnología Inalámbrica , Humanos
14.
J Bone Joint Surg Am ; 104(9): 813-820, 2022 05 04.
Artículo en Inglés | MEDLINE | ID: mdl-35041625

RESUMEN

BACKGROUND: Clinical case series have indicated that 1 or 2-compartment decompression of the anterior or lateral leg may be sufficient for release, but, currently, no cadaveric model has verified that approach. The objective of this study was to investigate the functional relationship between compartments by alternating sequences of infusion and fasciotomy release. METHODS: This study utilized multicompartment sequential pressurization with simultaneous monitoring by continuous pressure sensors to model compartment syndrome in a human cadaver leg. Subsequent sequential release of compartments and continuous streaming of pressure readings permitted unique insights. RESULTS: A leg model allowed the examination of pressure changes in all 4 compartments as treated with sequential fasciotomies. The successful modeling of lower-leg pressures consistent with compartment syndrome showed that discrepancies relative to accepted concepts were seen when the deep posterior compartment was pressurized in isolation. Also, release of 1 of the 2 of either the anterior or lateral compartments seems to be sufficient for decompression to acceptable pressure levels. CONCLUSIONS: The deep posterior compartment does not appear to be completely discrete and instead follows the pressurization curve of the posterior muscle group. This indicates that release of the deep posterior compartment may not be needed in all acute compartment syndrome scenarios. CLINICAL RELEVANCE: Surgical techniques can be modified for treatment of acute compartment syndrome to avoid large scar lengths, deep dissection, and multiple exposures that could improve patient outcomes.


Asunto(s)
Síndromes Compartimentales , Cadáver , Síndromes Compartimentales/etiología , Síndromes Compartimentales/cirugía , Fasciotomía/métodos , Humanos , Pierna/cirugía , Presión
15.
Knee ; 39: 279-290, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36332558

RESUMEN

BACKGROUND: Knee osteoarthritis (KOA) is increasingly prevalent in North American society. The significant societal burden it represents makes it essential to promote and target new treatments in earlier phases of the disease. Among others, subchondroplasty is a newly documented technique using calcium phosphate injection targeting the osteochondral lesions preceding KOA, also known as Bone Marrow Lesions (BMLs). This article aimed to review the existing literature on clinical and radiological outcomes of subchondroplasty in the treatment of BMLs in KOA. METHOD: A systematic review was performed using PubMed, Embase, Medline and Cochrane Database of Systematic Reviews. Studies on calcium phosphate injections into BMLs for KOA and its clinical and radiological outcomes were screened and reviewed by independent evaluators. RESULTS: After screening, ten articles were included, totaling 540 patients. Follow-up ranged from 6 months to 7 years. Overall, the procedure showed significant functional and quality of life improvement, as well as pain relief, as shown by Patients-Reported Outcomes Measures (PROMs). There were very few complications reported, the most important being leakage of calcium phosphate outside the targeted site. Conversion rate to total knee arthroplasty (TKA) ranged from 14 % to 30 % at 2 years post-procedure. Long term radiological outcomes have been poorly documented. CONCLUSIONS: Subchondroplasty is a promising avenue for the treatment of KOA. However, quality evidence is still required before any real conclusions and practical management guidelines can be drawn. Prospective, randomized studies with a control group and a rigorous assessment of long-term clinical and radiological outcomes are recommended.


Asunto(s)
Enfermedades Óseas , Enfermedades de los Cartílagos , Osteoartritis de la Rodilla , Humanos , Médula Ósea/diagnóstico por imagen , Médula Ósea/patología , Calidad de Vida , Estudios Prospectivos , Osteoartritis de la Rodilla/diagnóstico por imagen , Osteoartritis de la Rodilla/cirugía , Osteoartritis de la Rodilla/patología , Enfermedades de los Cartílagos/cirugía , Fosfatos de Calcio/uso terapéutico
16.
JBJS Case Connect ; 12(3)2022 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-36075019

RESUMEN

CASE: A 34-year-old man had an injury which resulted in pilon fracture and acute compartment syndrome of his forefoot. The case report describes the use of a novel minimally invasive dorsal approach for decompression of the lateral, central, medial, and interosseous compartments. The release was performed through multiple small incisions on the dorsal foot. The patient had complete relief with normal function of all muscle groups at 6 weeks and is now 18 months after surgery. He has returned to full activity. CONCLUSION: The successful decompression of the forefoot compartments through a percutaneous approach avoided known complications of muscle death, toe clawing, and secondary surgeries.


Asunto(s)
Síndromes Compartimentales , Adulto , Síndromes Compartimentales/complicaciones , Síndromes Compartimentales/cirugía , Pie/cirugía , Humanos , Masculino
17.
Sci Rep ; 12(1): 834, 2022 01 17.
Artículo en Inglés | MEDLINE | ID: mdl-35039588

RESUMEN

Surgical site infections (SSIs) account for a massive economic, physiological, and psychological burden on patients and health care providers. Sutures provide a surface to which bacteria can adhere, proliferate, and promote SSIs. Current methods for fighting SSIs involve the use of sutures coated with common antibiotics (triclosan). Unfortunately, these antibiotics have been rendered ineffective due to the increasing rate of antibiotic resistance. A promising new avenue involves the use of metallic nanoparticles (MNPs). MNPs exhibit low cytotoxicity and a strong propensity for killing bacteria while evading the typical antibiotic resistance mechanisms. In this work, we developed a novel MNPs dip-coating method for PDS-II sutures and explored the capabilities of a variety of MNPs in killing bacteria while retaining the cytocompatibility. Our findings indicated that our technique provided a homogeneous coating for PDS-II sutures, maintaining the strength, structural integrity, and degradability. The MNP coatings possess strong in vitro antibacterial properties against P aeruginosa and S. aureus-varying the %of dead bacteria from ~ 40% (for MgO NPs) to ~ 90% (for Fe2O3) compared to ~ 15% for uncoated PDS-II suture, after 7 days. All sutures demonstrated minimal cytotoxicity (cell viability > 70%) reinforcing the movement towards the use MNPs as a viable antibacterial technology.


Asunto(s)
Antibacterianos/administración & dosificación , Antiinfecciosos Locales/administración & dosificación , Infecciones Bacterianas/prevención & control , Materiales Biocompatibles Revestidos/administración & dosificación , Materiales Biocompatibles Revestidos/farmacología , Nanopartículas del Metal , Infección de la Herida Quirúrgica/prevención & control , Suturas , Tecnología Farmacéutica/métodos , Triclosán/administración & dosificación , Infecciones Bacterianas/etiología , Farmacorresistencia Bacteriana , Pseudomonas aeruginosa/efectos de los fármacos , Staphylococcus aureus/efectos de los fármacos , Infección de la Herida Quirúrgica/etiología , Suturas/efectos adversos , Suturas/microbiología
18.
Artículo en Inglés | MEDLINE | ID: mdl-34841190

RESUMEN

BACKGROUND: Acute compartment syndrome of the foot is a controversial topic. Release of the foot has been seen as complicated because of large incisions and postoperative morbidity, and there has been debate over whether this procedure is actually effective for releasing all areas of increased pressure. New sensor technology affords the opportunity to advance our understanding of acute compartment syndrome of the foot and its treatment. The purpose of the present study was to determine whether percutaneous decompression could be performed for the treatment of compartment syndrome in a forefoot model. METHODS: The present study utilized a validated continuous pressure sensor to model compartment syndrome in human cadaveric feet. We utilized a pressure-controlled saline solution infusion system to induce increased pressure. A novel percutaneous release of the forefoot was investigated to assess its efficacy in achieving decompression. RESULTS: For all cadaveric specimens, continuous pressure monitoring was accomplished with use of a continuous pressure sensor. There were 4 discrete compartment areas that could be reliably pressurized in all feet. The average baseline, pressurized, and post-release pressures (and standard deviations) were 4.5 ± 2.9, 43.8 ± 7.7, and 9.5 ± 3.6 mm Hg, respectively. Percutaneous decompression produced a significant decrease in pressure in all 4 compartments (p < 0.05). CONCLUSIONS: With use of continuous compartment pressure monitoring, 4 consistent areas were established as discrete compartments in the foot. All 4 compartments were pressurized with a standard pump system. With use of 2 small dorsal incisions, all 4 compartments were successfully released, with no injuries identified in the cutaneous nerve branches, extensor tendons, or arteries. These results have strong implications for the future of modeling compartment syndrome as well as for guiding clinical studies. CLINICAL RELEVANCE: A reproducible and accurate method of continuous pressure monitoring of foot compartments after trauma is needed (1) to reliably identify patients who are likely to benefit from compartment release and (2) to help avoid missed or evolving cases of acute compartment syndrome. In addition, a reproducible method for percutaneous compartment release that minimizes collateral structural damage and the need for secondary surgical procedures is needed.

19.
J Orthop Trauma ; 35(5): e165-e170, 2021 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-33844665

RESUMEN

OBJECTIVES: To evaluate if local delivery of boron can accelerate bone healing and examine if the bioactive salt impacts the osteogenic response of bone-derived osteoclasts and osteoblasts by the regulation of the Wnt/ß-catenin pathway. METHODS: Bilateral femoral cortical defects were created in 32 skeletally mature C57 mice. On the experimental side, boric acid (8 mg/kg concentration) was injected locally, whereas on the control side, saline was used. Mice were euthanized at 7, 14, and 28 days. MicroCT was used to quantify bone regeneration at the defect. Histological staining for alkaline phosphatase and tartrate-resistant acid phosphatase was used to quantify osteoblast and osteoclast activity, respectively. Immunohistochemical antibodies, ß-catenin, and CD34 were used to quantify active ß-catenin levels and angiogenesis, respectively. RESULTS: The boron group exhibited higher bone volume and trabecular thickness at 28 days on microCT. Both alkaline phosphatase activity and ß-catenin activity was significantly higher in the boron group at 7 days. In addition, CD34 staining revealed increased angiogenesis at 14 days in boron-treated groups. We found boron to have no association with osteoclast activity. CONCLUSIONS: This study shows that local delivery of boron is associated with an increase in osteoblast activity at early phases of healing. The corresponding increase in ß-catenin likely supports that boron increases osteoblast activity by the Wnt/ß-catenin pathway. Increased angiogenesis at 14 days could be a separate mechanism of increasing bone formation that is independent of Wnt/ß-catenin activation.


Asunto(s)
Boro , Osteoblastos , Animales , Regeneración Ósea , Diferenciación Celular , Ratones , Osteoclastos , Osteogénesis , Vía de Señalización Wnt
20.
Biotechnol J ; 15(9): e2000140, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32388907

RESUMEN

Infections are a huge economic liability to the health care system, although real-time detection can allow early treatment protocols to avoid some of this cost and patient morbidity and mortality. Pseudomonas aeruginosa (PA) is a drug-resistant gram-negative bacterium found ubiquitously in clinical settings, accounting for up to 27% of hospital acquired infections. PA secretes a vast array of molecules, ranging from secondary metabolites to quorum sensing molecules, of which many can be exploited to monitor bacterial presence. In addition to electrochemical immunoassays to sense bacteria via antigen-antibody interactions, PA pertains a distinct redox-active virulence factor called pyocyanin (PYO), allowing a direct electrochemical detection of the bacteria. There has been a surge of publications relating to the electrochemical tracing of PA via a myriad of novel biosensing techniques, materials, and methodologies. In addition to indirect methods, research approaches where PYO has been sensitively detected using surface modified electrodes are reviewed and compared with conventional PA-sensing methodologies. This review aims at presenting indirect and direct electrochemical methods currently developed using various surface modified electrodes, materials, and electrochemical configurations on their electrocatalytic effects on sensing of PA and in particular PYO.


Asunto(s)
Técnicas Biosensibles , Piocianina , Técnicas Electroquímicas , Electrodos , Humanos , Pseudomonas aeruginosa , Percepción de Quorum
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