RESUMO
Staphylococcus spp. represents the main mastitis agents in ruminants and contaminants of milk due to their expressive capacity to make biofilms. The aims in this study was evaluate evaluated the antimicrobial activity of Mauritia flexuosa L. extracts against Staphylococcus spp. adhered to a stainless steel surface. Two isolates from cows with clinical mastitis were evaluated; one was identified as Staphylococcus aureus, and the other Staphylococcus haemolyticus. Additionally the ATCC 25923 strain, S. aureus from human was evaluated. The chemical profile obtained from gas chromatography revealed the presence of carbohydrates, organic acids, and flavonoids. The minimum bactericidal concentrations of the ethanolic extract (EE) and aqueous extract (AE) were 4.4 and 5.82 mg/mL, respectively. After EE treatment at 4.4 mg/mL for 2.5 min, total removal of mature biofilms grown on stainless steel coupons was observed (reduction by 3.85-4.81 log units). This extract from M. flexuosa shows potential as an effective sanitizer and may represent a natural alternative against Staphylococcus spp.
Assuntos
Infecções Estafilocócicas , Staphylococcus aureus , Feminino , Humanos , Bovinos , Animais , Staphylococcus haemolyticus , Aço Inoxidável/farmacologia , Staphylococcus , Infecções Estafilocócicas/tratamento farmacológico , Biofilmes , Extratos Vegetais/farmacologiaRESUMO
Hybrid diamond-like carbon (DLC) with incorporated titanium dioxide (TiO2) nanoparticle coatings have low friction coefficient, high wear resistance, high hardness, biocompatibility, and high chemical stability. They could be employed to modify biomedical alloys surfaces for numerous applications in biomedical engineering. Here we investigate for the first time the in vivo inflammatory process of DLC coatings with incorporated TiO2 nanoparticles. TiO2-DLC films were grown on AISI 316 stainless-steel substrates using plasma-enhanced chemical vapor deposition. The coated substrates were implanted in CF1 mice peritoneum. The in vivo cytotoxicity and biocompatibility of the samples were analyzed from macrophage lavage. Analysis in the first weeks after implantation could be helpful to evaluate the acute cytotoxicity generated after a possible inflammatory process. The in vivo results showed no inflammatory process. A significant increase in nitric oxide production on the uncoated substrates was confirmed through cytometry, and the coated substrates demonstrated biocompatibility. The presence of TiO2 nanoparticles enhanced the wound healing activity, due to their astringent and antimicrobial properties. DLC and TiO2-DLC coatings were considered biocompatible, and the presence of TiO2 nanoparticles reduced the inflammatory reactions, increasing DLC biocompatibility.
Assuntos
Carbono/química , Membranas Artificiais , Nanopartículas Metálicas/química , Próteses e Implantes , Titânio/química , Ligas , Animais , Carbono/farmacologia , Materiais Revestidos Biocompatíveis/síntese química , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacologia , Diamante/química , Dureza , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos Peritoneais/fisiologia , Teste de Materiais , Nanopartículas Metálicas/uso terapêutico , Camundongos , Aço Inoxidável/química , Aço Inoxidável/farmacologia , Propriedades de Superfície , Titânio/farmacologiaRESUMO
BACKGROUND/PURPOSE (S): Nosocomial pathogens can develop biofilms on hospital surfaces and medical devices; however, few studies have focused on the evaluation of mono-and dual-species biofilms developed by nosocomial pathogens under different growth conditions. METHODS: This study investigated biofilm development by nosocomial pathogens (Acinetobacter baumannii, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa) on biomaterials in different culture media and their components of the extracellular matrix biofilm. RESULTS: The mono-species biofilms showed cell densities from 7.50 to 9.27 Log10 CFU/cm2 on natural rubber latex type I (NLTI) and from 7.58 to 8.79 Log10 CFU/cm2 on stainless steel (SS). Dual-species biofilms consisted of S. aureus + P. aeruginosa (7.87-8.27 Log10 CFU/cm2 in TSBP and TSBME onto SS; p < 0.05), E. coli + P. aeruginosa (8.32-8.86 Log10 CFU/cm2 in TSBME onto SS and TSBP onto NLTI; p < 0.05), and S. aureus + E. coli (7.82 Log10 CFU/cm2 in TSBME onto SS; p < 0.05). Furthermore, biofilm detachment after proteinase K treatment was 5.54-32.81% compared to 7.95-24.15% after DNase I treatment in the mono-dual species biofilm matrix. Epifluorescence microscopy and scanning electron microscopy (SEM) enabled visualizing the bacteria and extracellular polymeric substances of biofilms on SS and NLTI. CONCLUSION: Nosocomial pathogens can develop biofilms on biomaterials. Mono-species biofilms of Gram-negative bacteria showed lower densities than dual-species biofilms in TSBME and TSBP. Additionally, dual-species biofilms showed a higher concentration of proteins and eDNA in the extracellular matrix.
Assuntos
Materiais Biocompatíveis/farmacologia , Biofilmes/efeitos dos fármacos , Infecção Hospitalar/microbiologia , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Aderência Bacteriana , Proteínas de Bactérias/metabolismo , Biofilmes/crescimento & desenvolvimento , Técnicas de Cocultura , Contagem de Colônia Microbiana , Meios de Cultura/farmacologia , DNA Bacteriano/metabolismo , Matriz Extracelular de Substâncias Poliméricas/efeitos dos fármacos , Matriz Extracelular de Substâncias Poliméricas/metabolismo , Matriz Extracelular de Substâncias Poliméricas/ultraestrutura , Humanos , Borracha/farmacologia , Aço Inoxidável/farmacologiaRESUMO
Operative fixation of acetabular fractures involving the quadrilateral surface presents a challenging clinical scenario. Classically, quadrilateral plate buttress was achieved via the use of a "seven" plate. More recently, the use of an anatomic, pre-contoured design has been gaining popularity due to its pre-contoured shape and larger footprint, allowing for a wider quadrilateral plate buttress. The current study presents using a stainless steel locking calcaneal plate to obtain similar surface area coverage as the modern pre-contoured quadrilateral plate, but at a lower cost.Level of evidence IV.
Assuntos
Acetábulo , Placas Ósseas , Fixação Interna de Fraturas , Fraturas Ósseas , Complicações Pós-Operatórias/prevenção & controle , Acetábulo/diagnóstico por imagem , Acetábulo/lesões , Acetábulo/cirurgia , Adulto , Fenômenos Biomecânicos , Parafusos Ósseos , Fixação Interna de Fraturas/instrumentação , Fixação Interna de Fraturas/métodos , Fixação Interna de Fraturas/reabilitação , Consolidação da Fratura , Fraturas Ósseas/diagnóstico , Fraturas Ósseas/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Aço Inoxidável/farmacologia , Resultado do TratamentoRESUMO
In this study, we report a hybrid organic-inorganic TEOS-MTES (tetraethylorthosilicate-methyltriethoxysilane) sol-gel-made coating as a potential solution to improve the in vivo performance of AISI 316L stainless steel, which is used as permanent bone implant material. These coatings act as barriers for ion migration, promoting the bioactivity of the implant surface. The addition of SiO(2) colloidal particles to the TEOS-MTES sol (10 or 30 mol.%) leads to thicker films and also acts as a film reinforcement. Also, the addition of bioactive glass-ceramic particles is considered responsible for enhancing osseointegration. In vitro assays for bioactivity in simulated body fluid showed the presence of crystalline hydroxyapatite (HA) crystals on the surface of the double coating with 10mol.% SiO(2) samples on stainless steel after 30 days of immersion. The HA crystal lattice parameters are slightly different from stoichiometric HA. In vivo implantation experiments were carried out in a rat model to observe the osteointegration of the coated implants. The coatings promote the development of newly formed bone in the periphery of the implant, in both the remodellation zone and the marrow zone. The quality of the newly formed bone was assessed for mechanical and structural integrity by nanoindentation and small-angle X-ray scattering experiments. The different amount of colloidal silica present in the inner layer of the coating slightly affects the material quality of the newly formed bone but the nanoindentation results reveal that the lower amount of silica in the coating leads to mechanical properties similar to cortical bone.
Assuntos
Osso e Ossos/efeitos dos fármacos , Materiais Revestidos Biocompatíveis/farmacologia , Géis/química , Implantes Experimentais , Osseointegração/efeitos dos fármacos , Aço Inoxidável/farmacologia , Animais , Osso e Ossos/citologia , Osso e Ossos/diagnóstico por imagem , Osso e Ossos/ultraestrutura , Durapatita/química , Microscopia Eletrônica de Varredura , Nanotecnologia , Espectroscopia Fotoeletrônica , Implantação de Prótese , Radiografia , Ratos , Espalhamento a Baixo Ângulo , Difração de Raios XRESUMO
Estuda-se a reaçäo tecidual a alguns materiais de implante (Aço-Inoxidável, Vitallium, Tântalo e Polietileno) através de modelo experimental em cäes. Foram realizados estudos macro e microscópico das amostras obtidas. Os resultados mostraram que o Vitalliun é o menos reativo entre os tecidos, vindo a seguir o Aço-Inoxidável e o Polietileno, sendo o Tântalo o material menos inerte entre os testados