RESUMO
ABSTRACT: Fostamatinib, a recently approved Syk inhibitor used in adult primary immune thrombocytopenia (ITP), has been shown to be safe and effective in this disorder. However, clinical trial results may not be similarly reproduced in clinical practice. Here, 138 patients with ITP (both primary and secondary) from 42 Spanish centers who had been treated with fostamatinib were evaluated prospectively and retrospectively. The median age of our cohort (55.8% women) was 66 years (interquartile range [IQR], 56-80). The median time since ITP diagnosis at fostamatinib initiation was 51 months (IQR, 10-166). The median number of therapies before fostamatinib initiation was 4 (IQR, 2-5), including eltrombopag (76.1%), romiplostim (57.2%), and IV immunoglobulins (44.2%). Fifty-eight patients (42.0%) had signs/symptoms of bleeding in the month before treatment initiation. Seventy-nine percent of patients responded to fostamatinib with 53.6% complete responses (platelet count > 100 × 109/L). Eighty-three patients (60.1%) received fostamatinib monotherapy, achieving a high response rate (85.4%). The proportion of time in response during the 27-month period examined was 83.3%. The median time to platelet response was 11 days (IQR, 7-21). Sixty-seven patients (48.5%) experienced adverse events, mainly grade 1 to 2; the commonest of which were diarrhea (n = 28) and hypertension (n = 21). One patient had deep venous thrombosis, and one patient developed acute myocardial infarction. Fostamatinib was shown to be effective with good safety profile in patients with primary and secondary ITP across a wide age spectrum in this real-world study.
Assuntos
Aminopiridinas , Morfolinas , Oxazinas , Púrpura Trombocitopênica Idiopática , Piridinas , Pirimidinas , Humanos , Feminino , Masculino , Pessoa de Meia-Idade , Púrpura Trombocitopênica Idiopática/tratamento farmacológico , Idoso , Oxazinas/uso terapêutico , Oxazinas/efeitos adversos , Idoso de 80 Anos ou mais , Pirimidinas/uso terapêutico , Pirimidinas/efeitos adversos , Morfolinas/uso terapêutico , Morfolinas/efeitos adversos , Piridinas/uso terapêutico , Piridinas/efeitos adversos , Aminopiridinas/uso terapêutico , Aminopiridinas/efeitos adversos , Estudos Retrospectivos , Resultado do Tratamento , Quinase Syk/antagonistas & inibidores , Inibidores de Proteínas Quinases/uso terapêutico , Inibidores de Proteínas Quinases/efeitos adversos , Contagem de Plaquetas , Estudos ProspectivosRESUMO
Immunoparesis is the suppression of normal polyclonal immunoglobulins and is present in most patients with newly diagnosed multiple myeloma (MM). The association of immunoparesis at diagnosis, and particularly its recovery along with treatment, with survival in patients ineligible for autologous stem-cell transplantation (ASCT) has not been well established. This retrospective study evaluated the impact of immunoparesis in 431 patients diagnosed with MM, ineligible for ASCT, with a median overall survival of 36 months [95% confidence interval (CI): 31-40]. Immunoparesis was present in 81.2% of patients at diagnosis and was associated with a trend to a worse overall response rate (ORR: 84.8% vs. 74.9%; OR 1.88 (95% CI: 0.97-3.63), shorter progression-free survival (PFS) [22.0 vs. 18.2 months; hazard ratio (HR) 0.775; 95%CI: 0.590-1.018; p = 0.066], and overall survival (OS) (45.9 vs. 34.2 months; HR 0.746; 95% CI: 0.551-1.010; p = 0.057). Twenty-four per cent of patients who had immunoparesis at diagnosis recovered polyclonal immunoglobulins in the follow-up period. Interestingly, these patients had a better ORR (96.3% vs. 68.2%; OR 12.29 (95% CI: 3.77-40.06), PFS (HR 0.703; 95CI%: 0.526-0.941; p = 0.018) and OS (HR 0.678; 95 CI%: 0.503-0.913; p = 0.011) than patients who did not recover it. In summary, restoring a healthy immune system along with first-line treatment in patients with MM, not receiving ASCT, is associated with better outcomes.
Assuntos
Transplante de Células-Tronco Hematopoéticas , Mieloma Múltiplo , Intervalo Livre de Doença , Humanos , Imunoglobulinas , Mieloma Múltiplo/diagnóstico , Prognóstico , Intervalo Livre de Progressão , Estudos Retrospectivos , Transplante AutólogoRESUMO
Patients with low-risk myelodysplastic syndromes (MDS) usually develop iron overload. This leads to a high level of oxidative stress in the bone marrow (BM) and increases haematopoietic cell dysfunction. Our objective was to analyse whether chelation with deferasirox (DFX) alleviates the consequences of oxidative stress and improves BM cell functionality. We analysed 13 iron-overloaded MDS patients' samples before and 4-10 months after treatment with DFX. Using multiparametric flow cytometry analysis, we measured intracellular reactive oxygen species (ROS), DNA oxidation and double strand breaks. Haematopoietic differentiation capacity was analysed by colony-forming unit (CFU) assays. Compared to healthy donors, MDS showed a higher level of intracellular ROS and DNA oxidative damage in BM cells. DNA oxidative damage decreased following DFX treatment. Furthermore, the clonogenic assays carried out before treatment suggest an impaired haematopoietic differentiation. DFX seems to improve this capacity, as illustrated by a decreased cluster/CFU ratio, which reached values similar to controls. We conclude that BM cells from MDS are subject to higher oxidative stress conditions and show an impaired haematopoietic differentiation. These adverse features seem to be partially rectified after DFX treatment.
Assuntos
Dano ao DNA/efeitos dos fármacos , Deferasirox/uso terapêutico , Quelantes de Ferro/uso terapêutico , Síndromes Mielodisplásicas/tratamento farmacológico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/metabolismo , Células da Medula Óssea/fisiologia , Estudos de Casos e Controles , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/fisiologia , Deferasirox/farmacologia , Humanos , Quelantes de Ferro/farmacologia , Sobrecarga de Ferro/tratamento farmacológico , Sobrecarga de Ferro/etiologia , Sobrecarga de Ferro/genética , Sobrecarga de Ferro/metabolismo , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/complicações , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/metabolismo , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Estudos Prospectivos , Espécies Reativas de Oxigênio/metabolismo , Células-Tronco/efeitos dos fármacos , Células-Tronco/fisiologia , Adulto JovemRESUMO
Immunoparesis or suppression of polyclonal immunoglobulins is a very common condition in newly diagnosed myeloma patients. However, the recovery of polyclonal immunoglobulins in the setting of immune reconstitution after autologous stem cell transplantation and its effect on outcome has not yet been explored. We conducted this study in a cohort of 295 patients who had undergone autologous transplantation. In order to explore the potential role of immunoglubulin recovery as a dynamic predictor of progression or survival after transplantation, conditional probabilities of progression-free survival and overall survival were estimated according to immunoglobulin recovery at different time points using a landmark approach. One year after transplant, when B-cell reconstitution is expected to be completed, among 169 patients alive and progression free, 88 patients (52%) showed immunoglobulin recovery and 81 (48%) did not. Interestingly, the group with immunoglobulin recovery had a significantly longer median progression-free survival than the group with persistent immunoparesis (median 60.4 vs. 27.9 months, respectively; Hazard Ratio: 0.45, 95%Confidence Interval: 0.31-0.66; P<0.001), and improved overall survival (11.3 vs. 7.3 years; Hazard Ratio: 0.45, 95%Confidence Interval: 0.27-0.74; P=0.002). Furthermore, the percentage of normal plasma cells detected by flow cytometry in the bone marrow assessed at day 100 after transplantation was associated with the immunoglobulin recovery at that time and may predict immunoglobulin recovery in the subsequent months: nine months and one year. In conclusion, the recovery of polyclonal immunoglobulins one year after autologous transplantation in myeloma patients is an independent long-term predictor marker for progression and survival.
Assuntos
Biomarcadores Tumorais/metabolismo , Transplante de Células-Tronco Hematopoéticas/métodos , Imunoglobulinas/metabolismo , Mieloma Múltiplo/terapia , Adulto , Idoso , Progressão da Doença , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/metabolismo , Mieloma Múltiplo/patologia , Avaliação de Resultados em Cuidados de Saúde/métodos , Avaliação de Resultados em Cuidados de Saúde/estatística & dados numéricos , Valor Preditivo dos Testes , Prognóstico , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Fatores de Tempo , Transplante AutólogoAssuntos
Citometria de Fluxo , Imunofenotipagem , Mieloma Múltiplo/diagnóstico , Mieloma Múltiplo/metabolismo , Células Neoplásicas Circulantes/metabolismo , Plasmócitos/metabolismo , Citometria de Fluxo/métodos , Humanos , Imunofenotipagem/métodos , Mieloma Múltiplo/mortalidade , Mieloma Múltiplo/terapia , Células Neoplásicas Circulantes/patologia , Plasmócitos/patologia , PrognósticoRESUMO
BACKGROUND: MicroRNAs are known to inhibit gene expression by binding to the 3'UTR of the target transcript. Downregulation of miR-223 has been recently reported to have prognostic significance in CLL. However, there is no evidence of the pathogenetic mechanism of this miRNA in CLL patients. METHODS: By applying next-generation sequencing techniques we have detected a common polymorphism (rs2307842), in 24% of CLL patients, which disrupts the binding site for miR-223 in HSP90B1 3'UTR. We investigated whether miR-223 directly targets HSP90B1 through luciferase assays and ectopic expression of miR-223. Quantitative real-time polymerase chain reaction and western blot were used to determine HSP90B1 expression in CLL patients. The relationship between rs2307842 status, HSP90B1 expression and clinico-biological data were assessed. RESULTS: HSP90B1 is a direct target for miR-223 by interaction with the putative miR-223 binding site. The analysis in paired samples (CD19+ fraction cell and non-CD19+ fraction cell) showed that the presence of rs2307842 and IGHV unmutated genes determined HSP90B1 overexpression in B lymphocytes from CLL patients. These results were confirmed at the protein level by western blot. Of note, HSP90B1 overexpression was independently predictive of shorter time to the first therapy in CLL patients. By contrast, the presence of rs2307842 was not related to the outcome. CONCLUSIONS: HSP90B1 is a direct target gene of miR-223. Our results provide a plausible explanation of why CLL patients harboring miR-223 downregulation are associated with a poor outcome, pointing out HSP90B1 as a new pathogenic mechanism in CLL and a promising therapeutic target.
Assuntos
Sequenciamento de Nucleotídeos em Larga Escala/métodos , Leucemia Linfocítica Crônica de Células B/genética , Leucemia Linfocítica Crônica de Células B/patologia , Glicoproteínas de Membrana/genética , MicroRNAs/genética , Análise de Sequência de DNA/métodos , Regiões 3' não Traduzidas , Adulto , Idoso , Idoso de 80 Anos ou mais , Sítios de Ligação , Linhagem Celular Tumoral , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Leucemia Linfocítica Crônica de Células B/metabolismo , Masculino , Glicoproteínas de Membrana/metabolismo , MicroRNAs/química , MicroRNAs/metabolismo , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , PrognósticoRESUMO
We report the formation of covalently bound alkyl layers onto oxidized Pt (PtOx) substrates by reaction with 1-alkenes as a novel way to bind organic molecules to metal surfaces. The organic layers were characterized by static contact angle, infrared reflection absorption spectroscopy (IRRAS), X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). The grafted alkyl layers display a hydrolytic stability that is comparable to that of alkyl thiols on Au. PtOx-alkene attachment is compatible with terminal ester moieties enabling further anchoring of functional groups, such as redox-active ferrocene, and thus has great potential to extend monolayer chemistry on noble metals.
RESUMO
The rate of formation of covalently linked organic monolayers on HF-etched silicon carbide (SiC) is greatly increased by microwave irradiation. Upon microwave treatment for 60 min at 100 °C (60 W), 1-alkenes yield densely packed, covalently attached monolayers on flat SiC surfaces, a process that typically takes 16 h at 130 °C under thermal conditions. This approach was extended to SiC microparticles. The monolayers were characterized by X-ray photoelectron spectroscopy and static water contact angle measurements. The microwave-assisted reaction is compatible with terminal functionalities such as alkenes that enable subsequent versatile "click" chemistry reactions, further broadening the range and applicability of chemically modified SiC surfaces.
Assuntos
Alcenos/química , Compostos Inorgânicos de Carbono/química , Micro-Ondas , Compostos de Silício/química , Espectroscopia FotoeletrônicaRESUMO
A comparative study is presented of the hydrolytic and thermal stability of 24 different kinds of monolayers on Si(111), Si(100), SiC, SiN, SiO2, CrN, ITO, PAO, Au, and stainless steel surfaces. These surfaces were modified utilizing appropriate organic compounds having a constant alkyl chain length (C18), but with different surface-reactive groups, such as 1-octadecene, 1-octadecyne, 1-octadecyltrichlorosilane, 1-octadecanethiol, 1-octadecylamine and 1-octadecylphosphonic acid. The hydrolytic stability of obtained monolayers was systematically investigated in triplicate in constantly flowing aqueous media at room temperature in acidic (pH 3), basic (pH 11), phosphate buffer saline (PBS) and deionized water (neutral conditions), for a period of 1 day, 7 days, and 30 days, yielding 1152 data points for the hydrolytic stability. The hydrolytic stability was monitored by static contact angle measurements and X-ray photoelectron spectroscopy (XPS). The covalently bound alkyne monolayers on Si(111), Si(100), and SiC were shown to be among the most stable monolayers under acidic and neutral conditions. Additionally, the thermal stability of 14 different monolayers was studied in vacuum using XPS at elevated temperatures (25-600 °C). Similar to the hydrolytic stability, the covalently bound both alkyne and alkene monolayers on Si(111), Si(100) and SiC started to degrade from temperatures above 260 °C, whereas on oxide surfaces (e.g., PAO) phosphonate monolayers even displayed thermal stability up to â¼500 °C.
Assuntos
Ouro/química , Temperatura Alta , Hidrocarbonetos/química , Compostos de Silício/química , Concentração de Íons de Hidrogênio , HidróliseRESUMO
Nanoscale science refers to the study and manipulation of matter at the atomic and molecular scales, including nanometer-sized single objects, while nanotechnology is used for the synthesis, characterization, and for technical applications of structures up to 100 nm size (and more). The broad nature of the fields encompasses disciplines such as solid-state physics, microfabrication, molecular biology, surface science, organic chemistry and also virology. Indeed, viruses and viral particles constitute nanometer-sized ordered architectures, with some of them even able to self-assemble outside cells. They possess remarkable physical, chemical and biological properties, their structure can be tailored by genetic engineering and by chemical means, and their production is commercially viable. As a consequence, viruses are becoming the basis of a new approach to the manufacture of nanoscale materials, made possible only by the development of imaging and manipulation techniques. Such techniques reach the scale of single molecules and nanoparticles. The most important ones are electron microscopy and scanning probe microscopy (both awarded with the Nobel Prize in Physics 1986 for the engineers and scientists who developed the respective instruments). With nanotechnology being based more on experimental than on theoretical investigations, it emerges that physical virology can be seen as an intrinsic part of it.
Assuntos
Bacteriófagos , Nanopartículas/química , Nanotecnologia , Vírus de Plantas , Animais , HumanosRESUMO
Traditional wound dressings have not been able to satisfy the needs of the regenerative medicine biomedical area. With the aim of improving tissue regeneration, nanofiber-based wound dressings fabricated by electrospinning (ES) processes have emerged as a powerful approach. Nowadays, nanofiber-based bioactive dressings are mainly developed with a combination of natural and synthetic polymers, such as polycaprolactone (PCL) and chitosan (CHI). Accordingly, herein, PCL/CHI nanofibers have been developed with varying PCL:CHI weight ratios (9:1, 8:2 and 7:3) or CHI viscosities (20, 100 and 600 mPa·s) using a novel alternating current ES (ACES) process. Such nanofibers were thoroughly characterized by determining physicochemical and nanomechanical properties, along with wettability, absorption capacity and hydrolytic plus enzymatic stability. Furthermore, PCL/CHI nanofiber biological safety was validated in terms of cytocompatibility and hemocompatibility (hemolysis < 2%), in addition to a notable antibacterial performance (bacterial reductions of 99.90% for S. aureus and 99.91% for P. aeruginosa). Lastly, the enhanced wound healing activity of PCL/CHI nanofibers was confirmed thanks to their ability to remarkably promote cell proliferation, which make them ideal candidates for long-term applications such as wound dressings.
RESUMO
The prognostic impact of the aberrant hypermethylation in response to azacytidine (AZA) remains to be determined. Therefore, we have analyzed the influence of the methylation status prior to AZA treatment on the overall survival and clinical response of myeloid malignancies. DNA methylation status of 24 tumor suppressor genes was analyzed by methylation-specific multiplex ligation-dependent probe amplification in 63 patients with myelodysplastic syndromes and acute myeloid leukemia treated with azacytidine. Most patients (73 %) showed methylation of at least one gene, but only 12 % of patients displayed ≥3 methylated genes. The multivariate analysis demonstrated that the presence of a high number (≥2) of methylated genes (P = 0.022), a high WBC count (P = 0.033), or anemia (P = 0.029) were independent prognostic factors associated with shorter overall survival. The aberrant methylation status did not correlate with the response to AZA, although four of the five patients with ≥3 methylated genes did not respond. By contrast, favorable cytogenetics independently influenced the clinical response to AZA as 64.7 % of patients with good-risk cytogenetic abnormalities responded (P = 0.03). Aberrant methylation status influences the survival of patients treated with AZA, being shorter in those patients with a high number of methylated genes.
Assuntos
Antimetabólitos Antineoplásicos/uso terapêutico , Azacitidina/uso terapêutico , Metilação de DNA/genética , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/genética , Síndromes Mielodisplásicas/tratamento farmacológico , Síndromes Mielodisplásicas/genética , Idoso , Idoso de 80 Anos ou mais , Análise Citogenética/métodos , Metilação de DNA/efeitos dos fármacos , Feminino , Humanos , Leucemia Mieloide Aguda/mortalidade , Masculino , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/mortalidade , Prognóstico , Taxa de Sobrevida/tendências , Resultado do TratamentoRESUMO
The wetting and dewetting behavior of biological nanostructures and to a greater degree single molecules is not well-known even though their contact with water is the basis for all biology. Here, we show that environmental electron microscopy (EM) can be applied as a means of imaging the condensation of water onto viruses. We captured the formation of submicrometer water droplets and filaments on single viral particles by environmental EM and by environmental transmission EM. The condensate structures are compatible with capillary condensation between adsorbed virus particles and with known droplet shapes on patterned surfaces. Our results confirm that such droplets exist down to <50 nm. The viruses preserved their shape after a condensation/evaporation cycle as expected from their stability in air and water. Moreover we developed procedures that overcome problems of beam damage and of resolving structures with a low atomic number.
Assuntos
Vírus/química , Água/química , Adsorção , Microscopia Eletrônica , Tamanho da Partícula , Propriedades de SuperfícieAssuntos
Corpos Estranhos/complicações , Gastroscopia , Pâncreas/lesões , Estômago/lesões , Animais , Antibacterianos/uso terapêutico , Osso e Ossos , Peixes , Corpos Estranhos/diagnóstico por imagem , Corpos Estranhos/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Pâncreas/diagnóstico por imagem , Peritonite/dietoterapia , Peritonite/tratamento farmacológico , Peritonite/etiologia , Estômago/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Ferimentos e Lesões/diagnóstico por imagem , Ferimentos e Lesões/cirurgiaAssuntos
Junção Esofagogástrica/diagnóstico por imagem , Tumores Fibrosos Solitários/diagnóstico por imagem , Neoplasias Gástricas/diagnóstico por imagem , Biomarcadores Tumorais , Cárdia/diagnóstico por imagem , Cárdia/patologia , Cárdia/cirurgia , Diagnóstico Diferencial , Junção Esofagogástrica/patologia , Junção Esofagogástrica/cirurgia , Tumores do Estroma Gastrointestinal/diagnóstico , Gastroscopia , Hematemese/etiologia , Humanos , Masculino , Melena/etiologia , Pessoa de Meia-Idade , Tumores Fibrosos Solitários/complicações , Tumores Fibrosos Solitários/patologia , Tumores Fibrosos Solitários/cirurgia , Neoplasias Gástricas/complicações , Neoplasias Gástricas/patologia , Neoplasias Gástricas/cirurgia , Tomografia Computadorizada por Raios XRESUMO
OBJECTIVE: The objective of this article is to describe and show the results of a simulation training interprofesional program to meet a training need of Surgical area professionals in management in cardiovascular surgery emergencies in Valdecilla Hospital. MATERIAL: The activity was aimed to train at the 42 nurses in rotation in the surgical area, nursing assistances, cardiovascular surgeons and anesthetists. For it was made a study of the training needs and were designed clinical simulation escenarios, theoretical sessions as well in workshops usual workplace. RESULTS: The training project was conducted in four phases between May 21 to June 18, 2012, within which were 3 clinical cases for multidisciplinary training in emergency usual CCV. With the full participation of 65 professionals and 17 instructors, after further analysis to cases, results were achieved improved teamwork, and picked up, several changes to be made in the organization of the service. CONCLUSIONS: Clinical simulation mode responds to adult learning, based on their own experience and personal reflection, and all in an environment that does not risk to patients or professionals. It is really helpful and flexible to meet different institutional challenges and where participants highlighted two key aspects in this activity such as the multidisciplinary team where they could train the professional standard and the possibility of analysis and reflection after the event to share experiences and look for areas of improvement among all the clinical team.
Assuntos
Procedimentos Cirúrgicos Cardiovasculares/educação , Simulação por Computador , Manequins , Tratamento de Emergência , HumanosRESUMO
Granular polymer hydrogels based on dynamic covalent bonds are attracting a great deal of interest for the design of injectable biomaterials. Such materials generally exhibit shear-thinning behavior and properties of self-healing/recovery after the extrusion that can be modulated through the interactions between gel microparticles. Herein, bulk macro-hydrogels based on thiolated-hyaluronic acid were produced by disulphide bond formation using oxygen as oxidant at physiological conditions and gelation kinetics were monitored. Three different thiol substitution degrees (SD%: 65%, 30% and 10%) were selected for hydrogel formation and fully characterized as to their stability in physiological medium and morphology. Then, extrusion fragmentation technique was applied to obtain hyaluronic acid microgels with dynamic disulphide bonds that were subsequently sterilized by autoclaving. The resulting granular hyaluronic hydrogels were able to form stable filaments when extruded through a syringe. Rheological characterization and cytotoxicity tests allowed to assess the potential of these materials as injectable biomaterials. The application of extrusion fragmentation for the formation of granular hyaluronic hydrogels and the understanding of the relation between the autoclaving processes and the resulting particle size and rheological properties should expand the development of injectable materials for biomedical applications.
RESUMO
In this work, we have studied structural and magnetic properties of LaFeO3 as a function of the particle size d, from bulk (d >> 1 µm) to nanoscale (d ≈ 30 nm). A large number of twins were observed for large particles that disappear for small particle sizes. This could be related to the softening of the FeO6 distortion as particle size decreases. It was observed that the bulk sample showed spin canting that disappeared for d ~ 125 nm and can be associated with the smoothening of the orthorhombic distortion. On the other hand, for d < 60 nm, the surface/volume ratio became high and, despite the high crystallinity of the nanoparticle, a notable exchange effect bias appeared, originated by two magnetic interactions: spin glass and antiferromagnetism. This exchange bias interaction was originated by the formation of a "magnetic core-shell": the broken bonds at the surface atoms give place to a spin glass behavior, whereas the inner atoms maintain the antiferromagnetic G-type order. The LaFeO3 bulk material was synthesized by the ceramic method, whereas the LaFeO3 nanoparticles were synthesized by the sol-gel method; the particle size was varied by annealing the samples at different temperatures. The physical properties of the materials have been investigated by XRD, HRTEM, TGA, and AC and DC magnetometry.
RESUMO
Today, the treatment of implant-associated infections with conventional mono-functional antibacterial coatings has not been effective enough for a prosperous long-term implantation. Therefore, biomedical industry is making considerable efforts on the development of novel antibacterial coatings with a combination of more than one antibacterial strategies that interact synergistically to reinforce each other. Therefore, in this work hyaluronic acid-based (HA) hydrogel coatings were created on the surface Ti6Al4V biomaterial with 1,4-butanediol diglycidyl ether (Ti-HABDDE) and divinyl sulfone (Ti-HADVS) crosslinking agents. Hydrogel coatings displayed an extraordinary in vivo biocompatibility, a remarkable ability to promote cell proliferation, differentiation and mineralization, and capability to sustainedly release drugs. Finally, HA-based hydrogel coatings demonstrated an outstanding multifunctional antibacterial activity: bacteria-repelling (51-55 % of S. aureus and 27-40 % of E. coli), bacteria-killing (82-119 % of S. aureus and 83-87 % of E. coli) and bactericide release killing (drug-loaded hydrogel coatings, R > 2).