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1.
Dis Model Mech ; 16(8)2023 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-37493341

RESUMO

To provide insight into the subclonal architecture and co-dependency patterns of the alterations in Waldenström's macroglobulinemia (WM), we performed single-cell mutational and protein profiling of eight patients. A custom panel was designed to screen for mutations and copy number alterations at the single-cell level in samples taken from patients at diagnosis (n=5) or at disease progression (n=3). Results showed that in asymptomatic WM at diagnosis, MYD88L265P was the predominant clonal alteration; other events, if present, were secondary and subclonal to MYD88L265P. In symptomatic WM, clonal diversity was more evident, uncovering combinations of alterations that synergized to promote clonal expansion and dominance. At disease progression, a dominant clone was observed, sometimes accompanied by other less complex minor clones, which could be consistent with a clonal selection process. Clonal diversity was also reduced, probably due to the effect of treatment. Finally, we combined protein expression with mutational analysis to map somatic genotype with the immunophenotype. Our findings provide a comprehensive view of the clonality of tumor populations in WM and how clonal complexity can evolve and impact disease progression.


Assuntos
Evolução Clonal , Variações do Número de Cópias de DNA , Mutação , Macroglobulinemia de Waldenstrom , Macroglobulinemia de Waldenstrom/diagnóstico , Macroglobulinemia de Waldenstrom/genética , Humanos , Análise de Célula Única , Análise Serial de Proteínas , Fator 88 de Diferenciação Mieloide/genética , Análise Mutacional de DNA
2.
Materials (Basel) ; 16(9)2023 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-37176307

RESUMO

The present study aims at the integration of the "oxalic conversion" route into "green chemistry" for the synthesis of copper oxide nanoparticles (CuO-NPs) with controllable structural, morphological, and magnetic properties. Two oxalate-containing precursors (H2C2O4.2H2O and (NH4)2C2O4.H2O) and different volume ratios of a mixed water/glycerol solvent were tested. First, the copper oxalates were synthesized and then subjected to thermal decomposition in air at 400 °C to produce the CuO powders. The purity of the samples was confirmed by X-ray powder diffraction (XRPD), and the crystallite sizes were calculated using the Scherrer method. The transmission electron microscopy (TEM) images revealed oval-shaped CuO-NPs, and the scanning electron microscopy (SEM) showed that morphological features of copper oxalate precursors and their corresponding oxides were affected by the glycerol (V/V) ratio as well as the type of C2O42- starting material. The magnetic properties of CuO-NPs were determined by measuring the temperature-dependent magnetization and the hysteresis curves at 5 and 300 K. The obtained results indicate the simultaneous coexistence of dominant antiferromagnetic and weak ferromagnetic behavior.

3.
Nanomaterials (Basel) ; 13(10)2023 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-37242073

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.

4.
Cancers (Basel) ; 15(5)2023 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-36900349

RESUMO

(1) Background: New therapeutic strategies have improved the prognosis of multiple myeloma (MM), changing the accepted view of this disease from being incurable to treatable. (2) Methods: We studied 1001 patients with MM between 1980 and 2020, grouping patients into ten-year periods by diagnosis 1980-1990, 1991-2000, 2001-2010 and 2011-2020. (3) Results: After 65.1 months of follow-up, the median OS of the cohort was 60.3 months, and OS increased significantly over time: 22.4 months in 1980-1990, 37.4 months in 1991-2000, 61.8 months in 2001-2010 and 103.6 months in 2011-2020 (p < 0.001). Using novel agents in the front-line setting for myeloma patients yielded a significantly better OS than in those treated with conventional therapies, especially when combinations of at least two novel agents were used. The median OS of patients treated with the combination of at least two novel agents in induction was significantly prolonged compared to those treated with a single novel agent or conventional therapy in induction: 143.3 vs. 61.0 vs. 42.2 months (p < 0.001). The improvement was apparent in all patients regardless of age at diagnosis. In addition, 132 (13.2%) patients were long-term survivors (median OS ≥ 10 years). Some independent clinical predictors of long-term survival were identified: ECOG < 1, age at diagnosis ≤ 65 years, non-IgA subtype, ISS-1 and standard-risk cytogenetic. Achieving CR and undergoing ASCT were positively associated with >10 years of survival. (4) Conclusions: The combination of novel agents appears to be the main factor for the improvement in survival in MM, which is becoming a chronic and even curable disease in a subtype of patients without high-risk features.

5.
Materials (Basel) ; 16(4)2023 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-36837202

RESUMO

We have investigated the structural, magnetic, and electrical transport properties of Pr0.7 Sr0.3 Mn(1-x)Cox O3 nanopowders (x = 0, 0.05, 0.10 and 0.15). The Pechini Sol-gel method was used to synthesize these nanopowders. X-ray diffraction at room temperature shows that all the nano powders have an orthorhombic structure of Pnma space group crystallography. The average crystallite size of samples x = 0, 0.05, 0.10, and 0.15 are 33.78 nm, 29 nm, 33.61 nm, and 24.27 nm, respectively. Semi-quantitative chemical analysis by energy dispersive spectroscopy (EDS) confirms the expected stoichiometry of the sample. Magnetic measurements indicate that all samples show a ferromagnetic (FM) to paramagnetic (PM) transition with increasing temperature. The Curie temperature TC gradually decreases (300 K, 270 K, 250 K, and 235 K for x = 0, 0.05, 0.10, and 0.15, respectively) with increasing Co concentrations. The M-H curves for all compounds reveal the PM behavior at 300 K, while the FM behavior characterizes the magnetic hysteresis at low temperature (5 K). The electrical resistivity measurements show that all compounds exhibit metallic behavior at low temperature (T < Tρ) well fitted by the relation ρ = ρ0 + ρ2T2 + ρ4.5T4.5 and semiconductor behavior above Tρ (T > Tρ), for which the electronic transport can be explained by the variable range hopping model and the adiabatic small polaron hopping model. All samples have significant magnetoresistance (MR) values, even at room temperature. This presented research provides an innovative and practical approach to develop materials in several technological areas, such as ultra-high density magnetic recording and magneto resistive sensors.

6.
Polymers (Basel) ; 15(4)2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36850248

RESUMO

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.

7.
Int J Biol Macromol ; 231: 123328, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36681215

RESUMO

Among biomedical community, great efforts have been realized to develop antibacterial coatings that avoid implant-associated infections. To date, conventional mono-functional antibacterial strategies have not been effective enough for successful long-term implantations. Consequently, researchers have recently focused their attention on novel bifunctional or multifunctional antibacterial coatings, in which two or more antibacterial mechanisms interact synergistically. Thus, in this work different chitosan-based (CHI) hydrogel coatings were created on Ti6Al4V surface using genipin (Ti-CHIGP) and polyethylene glycol (Ti-CHIPEG) crosslinking agents. Hydrogel coatings demonstrated an exceptional in vivo biocompatibility plus a remarkable ability to promote cell proliferation and differentiation. Lastly, hydrogel coatings demonstrated an outstanding bacteria-repelling (17-28 % of S. aureus and 33-43 % of E. coli repelled) and contact killing (186-222 % of S. aureus and 72-83 % of E. coli damaged) ability. Such bifunctional antibacterial activity could be further improved by the controlled release of drugs resulting in powerful multifunctional antibacterial coatings.


Assuntos
Quitosana , Quitosana/farmacologia , Hidrogéis/farmacologia , Staphylococcus aureus , Escherichia coli , Materiais Revestidos Biocompatíveis/farmacologia , Antibacterianos/farmacologia , Titânio/farmacologia
8.
Carbohydr Polym ; 301(Pt B): 120366, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36446504

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).


Assuntos
Materiais Biocompatíveis , Hidrogéis , Antibacterianos/farmacologia , Materiais Biocompatíveis/farmacologia , Escherichia coli , Ácido Hialurônico/farmacologia , Hidrogéis/farmacologia , Staphylococcus aureus
9.
Biomater Adv ; 139: 212992, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35882141

RESUMO

Great efforts have been performed on the production of advanced biomaterials with the combination of self-healing and wound healing properties in implant/tissue engineering biomedical area. Inspired by this idea, chitosan (CHI) based hydrogels can be used to treat a less investigated class of harmful chronic wounds: ulcers or pressure ulcers. Thus, CHI was crosslinked with previously synthesized polyethylene glycol diacid (PEG-diacid) to obtain different CHI-PEG hydrogel formulations with high H-bonding tendency resulting in self-repair ability. Here presented results show biocompatible, antibacterial, anti-inflammatory, and self-healing CHI-PEG hydrogels with a promising future in the treatment of ulcerated wounds by a significant improvement in metabolic activity (94.51 ± 4.38 %), collagen and elastin quantities (2.12 ± 0.63 µg collagen and 4.97 ± 0.61 µg elastin per mg dermal tissue) and histological analysis. Furthermore, cefuroxime (CFX), tetracycline (TCN) and amoxicillin (AMX) antibiotics, and acetylsalicylic acid (ASA) anti-inflammatory agent were sustainedly released for enhancing antibacterial and anti-inflammatory activities of hydrogels.


Assuntos
Quitosana , Antibacterianos/farmacologia , Anti-Inflamatórios/farmacologia , Materiais Biocompatíveis , Quitosana/farmacologia , Colágeno/farmacologia , Elastina , Humanos , Hidrogéis , Úlcera , Cicatrização
10.
Gels ; 8(4)2022 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-35448124

RESUMO

Hyaluronic acid (HA) injectable biomaterials are currently applied in numerous biomedical areas, beyond their use as dermal fillers. However, bacterial infections and painful inflammations are associated with healthcare complications that can appear after injection, restricting their applicability. Fortunately, HA injectable hydrogels can also serve as drug delivery platforms for the controlled release of bioactive agents with a critical role in the control of certain diseases. Accordingly, herein, HA hydrogels were crosslinked with 1 4-butanediol diglycidyl ether (BDDE) loaded with cefuroxime (CFX), tetracycline (TCN), and amoxicillin (AMX) antibiotics and acetylsalicylic acid (ASA) anti-inflammatory agent in order to promote antibacterial and anti-inflammatory responses. The hydrogels were thoroughly characterized and a clear correlation between the crosslinking grade and the hydrogels' physicochemical properties was found after rheology, scanning electron microscopy (SEM), thermogravimetry (TGA), and differential scanning calorimetry (DSC) analyses. The biological safety of the hydrogels, expected due to the lack of BDDE residues observed in 1H-NMR spectroscopy, was also corroborated by an exhaustive biocompatibility test. As expected, the in vitro antibacterial and anti-inflammatory activity of the drug-loaded HA-BDDE hydrogels was confirmed against Staphylococcus aureus by significantly decreasing the pro-inflammatory cytokine levels.

11.
Br J Haematol ; 198(2): 278-287, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35383901

RESUMO

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 Autólogo
12.
Int J Biol Macromol ; 203: 679-694, 2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35124016

RESUMO

Chitosan (CHI) based hydrogels promote wound healing and relieve inflammations and chronic infections. However, in hardly healable ulcers with excessively painful inflammations, anti-inflammatory activity of hydrogels can be enhanced by the sustained release of non-steroidal anti-inflammatory drugs or combining them with antibiotics. Thus, CHI was crosslinked with genipin (GP) to obtain biocompatible hydrogels. Moreover, their antibacterial activity was confirmed against Staphylococcus aureus and Escherichia coli with an almost 100% bacteria reduction and a potential antibacterial efficacy (R > 2). Furthermore, hydrogels effective healing of ulcerated wounds was corroborated by a significant improvement in metabolic activity (95.58 ± 4.40%), collagen and elastin quantities (1.48 ± 0.07 µg collagen and 5.82 ± 0.73 µg elastin per mg dermal tissue) and histological analysis. Finally, the sustained release of acetylsalicylic acid (ASA), cefuroxime (CFX), tetracycline (TCN) and amoxicillin (AMX) were studied, as well as their anti-inflammatory activity. Results confirm the synergistic anti-inflammatory activity by the significant reduction in the amount of pro-inflammatory cytokines when ASA was combined with CFX (5.39 ± 0.81 ng·mL-1 TNF-α), TCN (4.70 ± 0.21 ng·mL-1 TNF-α and 49.06 ± 9.64 ng·mL-1 IL-8), and AMX (2.28 ± 0.36 ng·mL-1 TNF-α, 14.84 ± 5.57 ng·mL-1 IL-8, and total IL-6 removal).


Assuntos
Quitosana , Hidrogéis , Antibacterianos/farmacologia , Anti-Inflamatórios/farmacologia , Quitosana/farmacologia , Hidrogéis/farmacologia , Iridoides , Cicatrização
13.
Biomedicines ; 9(9)2021 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-34572298

RESUMO

Hyaluronic acid (HA) hydrogels display a wide variety of biomedical applications ranging from tissue engineering to drug vehiculization and controlled release. To date, most of the commercially available hyaluronic acid hydrogel formulations are produced under conditions that are not compatible with physiological ones. This review compiles the currently used approaches for the development of hyaluronic acid hydrogels under physiological/mild conditions. These methods include dynamic covalent processes such as boronic ester and Schiff-base formation and click chemistry mediated reactions such as thiol chemistry processes, azide-alkyne, or Diels Alder cycloaddition. Thermoreversible gelation of HA hydrogels at physiological temperature is also discussed. Finally, the most outstanding biomedical applications are indicated for each of the HA hydrogel generation approaches.

14.
Metas enferm ; 24(5): 7-13, Jun. 2021. tab
Artigo em Espanhol | IBECS | ID: ibc-223136

RESUMO

Objetivo: analizar el efecto de la simulación clínica en el nivel de ansiedad pre/post-actividad formativa en varios grupos profesionales y en estudiantes de Enfermería, y evaluar la autoconfianza percibida antes/después de la simulación en cada grupo.Métodos: estudio cuasi-experimental en profesionales sanitarios (enfermeras, técnicos en cuidados auxiliares de Enfermería o TCAE y médicos) y estudiantes de Enfermería (4º curso) sometidos por primera vez a una intervención de simulación clínica en el Hospital General Universitario de Ciudad Real. Se evaluó el nivel de ansiedad estado antes/después de la simulación mediante el cuestionario STAI de Spielberg, y se valoró la autoconfianza percibida antes/después de la simulación. Se realizó análisis descriptivo. Se usó la t de Student para la comparación de medias. Se estableció significación estadística si p< 0,05.Resultados: participaron 53 sujetos, 43 (81,2%) profesionales y 10 (18,8%) estudiantes de Enfermería. Edad media (DE) fue 39 (11,8) años; 84,9% (n= 45) mujeres. El nivel de ansiedad medio (DE) al inicio de la simulación fue mayor en los estudiantes de Enfermería 24,6 (5,4) y menor en los médicos 14,4 (5,8). Tras la intervención se redujo la media (DE) del nivel de ansiedad-estado en todos los grupos, siendo significativo (p< 0,001) en TCAE -13,1 (6,9) y enfermeras -12,5 (8,4). Hubo un aumento del nivel de autoconfianza de todos los participantes al finalizar la actividad.Conclusiones: los profesionales que participaron por primera vez en una actividad de simulación clínica presentaron alto grado de ansiedad, aunque en médicos fue inferior. Hubo un descenso de la ansiedad y aumento de la confianza al final de la simulación clínica.(AU)


Objective: to analyze the effect of clinical simulation in the level of anxiety pre- and post- training activity in different professional groups and Nursing students, and to assess the self-confidence perceived before/after the simulation in each group.Methods: a quasi-experimental study in healthcare professionals (nurses, assistant nursing technicians or TCAE, and doctors), and Nursing students (4th year), who underwent for the first time a clinical simulation intervention at the Hospital General Universitario de Ciudad Real. The level of anxiety was evaluated before/after the simulation, through Spielberger’s STAI questionnaire, and the level of self-confidence perceived was also evaluated before / after the simulation. Descriptive analysis was conducted, and Student’s t test was used for mean comparison. Statistical significance was established at p< 0.05.Results: the study included 53 subjects: 43 (81.2%) were professionals and 10 (18.8%) were Nursing students; their mean age (SD) was 39 (11.8) years; and 84.9% (n= 45) were female. The mean anxiety level (SD) at the start of the simulation was higher in Nursing students, with 24.6 (5.4), and lower in doctors, with 14.4 (5.8). After the intervention, the mean (SD) level of anxiety-status was reduced in all groups; it was significant (p< 0.001) in the TCAE group, with -13.1 (6.9) and nurses, with -12.5 (8.4). There was an increase in the level of self-confidence in all participants by the end of the activity.Conclusions: the professionals who participated for the first time in a clinical simulation activity presented a high level of anxiety, though this was lower among doctors. There was a reduction in anxiety and increase in confidence by the end of the clinical simulation.(AU)


Assuntos
Humanos , Treinamento por Simulação , Relações Interprofissionais , Ansiedade , Pessoal de Saúde , Estudantes de Enfermagem , Aprendizagem
15.
Mater Sci Eng C Mater Biol Appl ; 125: 112102, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33965111

RESUMO

Hyaluronic acid (HA) solutions were crosslinked with divinyl sulfone (DVS) and subsequently loaded with antibiotic molecules to obtain biocompatible and antibacterial injectable hydrogels. The crosslinking degree of the hydrogels was modulated by varying the reaction time and the HA:DVS weight ratio. Synthesized HA-DVS hydrogels were characterized by their rheological properties, pore size, swelling capacity and hydrolytic and thermal degradation. Biocompatibility was assessed by measuring pH, osmolality and by in vitro cytotoxic assay. Acetyl salicylic (AAS) loaded hydrogels display anti-inflammatory properties in vitro, whereas cefuroxime (CFX), tetracycline (TCN) and amoxicillin (AMX) loaded hydrogels show in vitro antibacterial activity against Staphylococcus aureus. The combine use of antibiotics and AAS produces a synergic effect that reduces the S. aureus population up to a log10 reduction (R) of 5.55. Overall results show that antibiotic/AAS loaded HA-DVS hydrogels could be effectively used to combat S. aureus infections and to increase the antibacterial activity of antibiotics commonly used against S. aureus.


Assuntos
Ácido Hialurônico , Hidrogéis , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Liberação Controlada de Fármacos , Teste de Materiais , Staphylococcus aureus , Sulfonas
16.
Int J Biol Macromol ; 183: 1222-1235, 2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-33984386

RESUMO

Bacterial contamination in implanted biomedical devices is a critical daily concern. The most used material for permanent implant in biomedical field is Ti6Al4V alloy due to its beneficial mechanical properties and high biocompatibility. Accordingly, in this work different polymeric antibacterial coatings poly(N-vinyl pyrrolidone) (PVP), hyaluronic acid (HA) and chitosan (CHI) were developed and comparatively analysed for Ti6Al4V surface covering. The adhesion of these coatings to Ti6Al4V substrates were carried out after the conjugation of these polymers with the so well-known bioadhesive properties of catechol (CA) anchor group. These surface modifications were characterized by X-ray photoelectronic spectroscopy, contact angle measurements and atomic force microscopy. In addition, the stability of CA-conjugated polymeric coatings was compared with the coatings formed with unconjugated polymers. Finally, the cytocompatibility and antibacterial properties against gram-positive and gram-negative strains on coated Ti6Al4V substrates were assessed confirming the effectiveness of these polymeric coatings against bacterial infections for future applications in protecting biomedical implants.


Assuntos
Ligas/síntese química , Antibacterianos/síntese química , Catecóis/química , Ácido Hialurônico/química , Pirrolidinonas/química , Ligas/química , Ligas/farmacologia , Antibacterianos/química , Antibacterianos/farmacologia , Linhagem Celular , Quitosana , Materiais Revestidos Biocompatíveis/síntese química , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Humanos , Teste de Materiais , Testes de Sensibilidade Microbiana , Microscopia de Força Atômica , Espectroscopia Fotoeletrônica , Próteses e Implantes , Propriedades de Superfície , Titânio/química , Titânio/farmacologia
17.
Polymers (Basel) ; 13(4)2021 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-33671648

RESUMO

The transfer of some innovative technologies from the laboratory to industrial scale is many times not taken into account in the design and development of some functional materials such as hydrogels to be applied in the biomedical field. There is a lack of knowledge in the scientific field where many aspects of scaling to an industrial process are ignored, and products cannot reach the market. Injectable hydrogels are a good example that we have used in our research to show the different steps needed to follow to get a product in the market based on them. From synthesis and process validation to characterization techniques used and assays performed to ensure the safety and efficacy of the product, following regulation, several well-defined protocols must be adopted. Therefore, this paper summarized all these aspects due to the lack of knowledge that exists about the industrialization of injectable products with the great importance that it entails, and it is intended to serve as a guide on this area to non-initiated scientists. More concretely, in this work, the characteristics and requirements for the development of injectable hydrogels from the laboratory to industrial scale is presented in terms of (i) synthesis techniques employed to obtain injectable hydrogels with tunable desired properties, (ii) the most common characterization techniques to characterize hydrogels, and (iii) the necessary safety and efficacy assays and protocols to industrialize and commercialize injectable hydrogels from the regulatory point of view. Finally, this review also mentioned and explained a real example of the development of a natural hyaluronic acid hydrogel that reached the market as an injectable product.

18.
Polymers (Basel) ; 14(1)2021 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-35012187

RESUMO

Titanium (Ti) and its alloys have been demonstrated over the last decades to play an important role as inert materials in the field of orthopedic and dental implants. Nevertheless, with the widespread use of Ti, implant-associated rejection issues have arisen. To overcome these problems, antibacterial properties, fast and adequate osseointegration and long-term stability are essential features. Indeed, surface modification is currently presented as a versatile strategy for developing Ti coatings with all these challenging requirements and achieve a successful performance of the implant. Numerous approaches have been investigated to obtain stable and well-organized Ti coatings that promote the tailoring of surface chemical functionalization regardless of the geometry and shape of the implant. However, among all the approaches available in the literature to functionalize the Ti surface, a promising strategy is the combination of surface pre-activation treatments typically followed by the development of intermediate anchoring layers (self-assembled monolayers, SAMs) that serve as the supporting linkage of a final active layer. Therefore, this paper aims to review the latest approaches in the biomedical area to obtain bioactive coatings onto Ti surfaces with a special focus on (i) the most employed methods for Ti surface hydroxylation, (ii) SAMs-mediated active coatings development, and (iii) the latest advances in active agent immobilization and polymeric coatings for controlled release on Ti surfaces.

19.
Materials (Basel) ; 13(18)2020 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-32927796

RESUMO

The ultra-stable Y (H-USY) zeolite is used as catalyst for the conversion of plastic feedstocks into high added value products through catalytic cracking technologies. However, the energy requirements associated with these processes are still high. On the other hand, induction heating by magnetic nanoparticles has been exploited for different applications such as cancer treatment by magnetic hyperthermia, improving of water electrolysis and many other heterogeneous catalytic processes. In this work, the heating efficiency of γ-Fe2O3 nanoparticle impregnated zeolites is investigated in order to determine the potential application of this system in catalytic reactions promoted by acid catalyst centers under inductive heating. The γ-Fe2O3 nanoparticle impregnated zeolite has been investigated by X-ray diffraction, electron microscopy, ammonia temperature program desorption (NH3-TPD), H2 absorption, thermogravimetry and dc and ac-magnetometry. It is observed that the diffusion of the magnetic nanoparticles in the pores of the zeolite is possible due to a combined micro and mesoporous structure and, even when fixed in a solid matrix, they are capable of releasing heat as efficiently as in a colloidal suspension. This opens up the possibility of exploring the application at higher temperatures.

20.
J Clin Pathol ; 73(1): 14-16, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31434698

RESUMO

AIMS: Untranslated regions (UTRs) play an important role in post-transcriptional regulation of gene expression, including by modulating messenger RNA (mRNA) transport out of the nucleus, translation efficiency, subcellular localisation and stability. Any mutation in this region could alter the stability of mRNA and thereby affect protein synthesis. We analysed if a mutation located in the α complex protected region of the α1 globin gene could cause non-deletional α-thalassaemia by affecting post-transcriptional stability (mRNA stability). METHODS: A total of 14 patients without anaemia, normal or slight microcytosis and hypochromia (medium concentration haemoglobin [MCH] <27 pg) were studied. Haemoglobin subtypes were screened using capillary zone electrophoresis and ion-exchange high-performance liquid chromatography (VARIANT II ß-Thalassaemia Short Program). The most common α-globin mutations were identified by multiplex PCR (Alpha-Globin StripAssay kit) and the molecular characterisation by automatic sequencing of alpha globin genes. RESULTS: All of them shown a novel transversion mutation in nt 778 (C>A), which is located in the 3' UTR in the α complex protected region [HBA1: c.*+46C>A]. CONCLUSIONS: This mutation is in the αRNAmin binding site, so a single nucleotide substitution in this region can decrease mRNA stability by potentially compromising the binding of α-complex protein to αRNAmin, favouring the decay of α-globin mRNA via erythroid cell-enriched endoribonuclease cleavage. In this case, it is a non-deletional α-thalassaemia. However, in silico and empirical studies predicted that it could be a silent polymorphism. Functional studies should be carried out to confirm whether it is a pathological mutation or a silent polymorphism.


Assuntos
Regiões 3' não Traduzidas , Mutação , Polimorfismo Genético , Estabilidade de RNA , RNA Mensageiro/genética , alfa-Globinas/genética , Talassemia alfa/genética , Adolescente , Adulto , Estudos de Casos e Controles , Criança , Pré-Escolar , Análise Mutacional de DNA/métodos , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase Multiplex , Fenótipo , RNA Mensageiro/metabolismo , Fatores de Risco , alfa-Globinas/metabolismo , Talassemia alfa/sangue , Talassemia alfa/diagnóstico
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