Physical-chemical influences and cell behavior of natural compounds on titanium dental surfaces.

The present study evaluated the influence of carvacrol, terpinene-4-ol, and chlorhexidine on the physical-chemical properties of titanium surfaces, cell viability, proliferation, adhesion, and spreading of fibroblasts and osteoblasts in vitro. Titanium surfaces (Ti) were treated with Carvacrol (Cvc), Terpinen-4-ol (T4ol), Chlorhexidine (CHX), DMSO, and ultrapure water (Control group). Physical-chemical modifications were evaluated by surface wettability, the surface free energy (SFE) calculated from the contact angle values using the Owens-Wendt-Rabel-Kaeble (OWRK) equation, scanning electron microscopy (SEM) and energy dispersive spectrometry probe (EDS) system. Cells were seeded onto Ti-treated surfaces and incubated for 24 h and 72 h, then evaluated by Alamar blue assay and fluorescence microscopy. Surfaces treated with Cvc and T4ol showed the presence of Na, O, and Cl. All surfaces showed hydrophilic characteristics and SFE values between 5.5 mN/m and 3.4 mN/m. On the other hand, EDS peaks demonstrated the presence of O and Cl after CHX treatment. A reduction of cell viability and adhesion was noted on titanium surfaces treated with CHX after 24 and 72h. In conclusion, the results indicate that the decontamination with Cvc and T4ol on Ti surfaces does not alter the surface proprieties and allows an adequate interaction with cells involved in the re-osseointegration process such as fibroblasts and osteoblasts.

Physical-chemical influences and cell behavior of natural compounds on titanium dental surfaces

Abstract The present study evaluated the influence of carvacrol, terpinene-4-ol, and chlorhexidine on the physical-chemical properties of titanium surfaces, cell viability, proliferation, adhesion, and spreading of fibroblasts and osteoblasts in vitro. Titanium surfaces (Ti) were treated with Carvacrol (Cvc), Terpinen-4-ol (T4ol), Chlorhexidine (CHX), DMSO, and ultrapure water (Control group). Physical-chemical modifications were evaluated by surface wettability, the surface free energy (SFE) calculated from the contact angle values using the Owens-Wendt-Rabel-Kaeble (OWRK) equation, scanning electron microscopy (SEM) and energy dispersive spectrometry probe (EDS) system. Cells were seeded onto Ti-treated surfaces and incubated for 24 h and 72 h, then evaluated by Alamar blue assay and fluorescence microscopy. Surfaces treated with Cvc and T4ol showed the presence of Na, O, and Cl. All surfaces showed hydrophilic characteristics and SFE values between 5.5 mN/m and 3.4 mN/m. On the other hand, EDS peaks demonstrated the presence of O and Cl after CHX treatment. A reduction of cell viability and adhesion was noted on titanium surfaces treated with CHX after 24 and 72h. In conclusion, the results indicate that the decontamination with Cvc and T4ol on Ti surfaces does not alter the surface proprieties and allows an adequate interaction with cells involved in the re-osseointegration process such as fibroblasts and osteoblasts.

Resumo O presente estudo avaliou a influência do carvacrol, terpineno-4-ol e clorexidina nas propriedades físico-químicas de superfícies de titânio, viabilidade celular, proliferação, adesão e esplhamento de fibroblastos e osteoblastos in vitro. Superfícies de titânio (Ti) foram tratadas com Carvacrol (Cvc), Terpinen-4-ol (T4ol), Clorexidina (CHX), DMSO e água ultrapura (Grupo Controle). As modificações físico-químicas foram avaliadas pela molhabilidade da superfície, a energia livre de superfície (ELS) calculada a partir dos valores do ângulo de contato usando a equação de Owens-Wendt-Rabel-Kaeble (OWRK), microscopia eletrônica de varredura (MEV) e espectroscopia de raios X por energia dispersiva (EDS). As células foram semeadas em superfícies tratadas com Ti e incubadas por 24 h e 72 h, e avaliadas pelo ensaio Alamar blue e microscopia de fluorescência. As superfícies tratadas com Cvc e T4ol mostraram a presença de Na, O e Cl. Todas as superfícies apresentaram características hidrofílicas e valores de ELS entre 5,5 mN/m e 3,4 mN/m. Por outro lado, os picos de EDS demonstraram a presença de O e Cl após o tratamento com CHX. Uma redução da viabilidade celular e adesão foi observada em superfícies de titânio tratadas com CHX após 24 e 72h. Em conclusão, os resultados indicam que a descontaminação com Cvc e T4ol em superfícies de Ti não altera as propriedades da superfície e permite uma interação adequada com células envolvidas no processo de reosseointegração como fibroblastos e osteoblastos.

Silver nanoparticles stabilized by ramnolipids: Effect of pH.

Rhamnolipids are glycolipid biosurfactants that have remarkable physicochemical characteristics, such as the capacity for self-assembly, which makes these biomolecules a promising option for application in nanobiotechnology. Rhamnolipids produced from a low-cost carbon source (glycerol) were used to stabilize silver nanoparticles. Silver nanoparticles (AgNPs) have been the subject of studies due to their physical chemical as well as biological properties, which corroborate their catalytic and antimicrobial activity. We compared nanoparticles obtained with three different pH values during synthesis (5, 7 and 9) in the presence of rhamnolipids. Dynamic light scattering showed that larger particles were formed at pH 5 (78-190 nm) compared to pH 7 (6.5-43 nm) and 9 (5.6-28.1 nm). Moreover, nanoparticle stability (analyzed based on the zeta potential) was enhanced with the increase in pH from 5 to 9 (-29.86 ± 1.04, -37.83 ± 0.90 and -40.33 ± 0.57 mV, respectively). Field emission gun scanning electron microscopy confirmed the round morphology of the silver nanoparticles. The LSPR spectra of AgNP for the pHs studied are conserved. In conclusion, different pH values in the presence of rhamnolipids used in the synthesis of silver nanoparticles directly affect nanoparticle size and stability.

A long-term controlled drug-delivery with anionic beta cyclodextrin complex in layer-by-layer coating for percutaneous implants devices.

This study demonstrated a drug-delivery system with anionic beta cyclodextrin (ß-CD) complexes to retain tetracycline (TC) and control its release from multilayers of poly(acrylic acid) (PAA) and poly(l-lysine) (PLL) in a ten double layers ([PAA/PLL]10) coating onto titanium. The drug-delivery capacity of the multilayer system was proven by controlled drug release over 15 days and sustained released over 30 days. Qualitative images confirmed TC retention within the layer-by-layer (LbL) over 30 days of incubation. Antibacterial activity of TC/anionic ß-CD released from the LbL was established against Staphylococcus aureus species. Remarkably, [PAA/PLL]10/TC/anionic ß-CD antibacterial effect was sustained even after 30 days of incubation. The non-cytotoxic effect of the multilayer system revealed normal human gingival fibroblast growth. It is expected that this novel approach and the chemical concept to improve drug incorporation into the multilayer system will open up possibilities to make the drug release system more applicable to implantable percutaneous devices.

Analyses of Biofilm on Implant Abutment Surfaces Coating with Diamond-Like Carbon and Biocompatibility

Abstract The aim of this study was to evaluate the surface free energy (SFE), wetting and surface properties as well as antimicrobial, adhesion and biocompatibility properties of diamond-like carbon (DLC)-coated surfaces. In addition, the leakage of Escherichia coli through the abutment-dental implant interface was also calculated. SFE was calculated from contact angle values; R a was measured before and after DLC coating. Antimicrobial and adhesion properties against E. coli and cytotoxicity of DLC with human keratinocytes (HaCaT) were evaluated. Further, the ability of DLC-coated surfaces to prevent the migration of E. coli into the external hexagonal implant interface was also evaluated. A sterile technique was used for the semi-quantitative polymerase chain reaction (semi-quantitative PCR). The surfaces showed slight decreases in cell viability (p<0.05), while the SFE, R a, bacterial adhesion, antimicrobial, and bacterial infiltration tests showed no statistically significant differences (p>0.05). It was concluded that DLC was shown to be a biocompatible material with mild cytotoxicity that did not show changes in R a, SFE, bacterial adhesion or antimicrobial properties and did not inhibit the infiltration of E. coli into the abutment-dental implant interface.

Resumo O objetivo deste trabalho foi avaliar a energia livre de superfície (ELS), molhabilidade e propriedades de superfície assim como propriedades antimicrobianas, de adesão e biocompatibilidade de superfícies recobertas com Diamond-Like Carbon (DLC). Além disso, investigou-se a infiltração de Escherichia coli por meio da interface abutment-implante dentário. ELS foi calculada a partir dos valores de ângulo de contato; Ra foi medida antes e depois do revestimento com DLC. Foram avaliadas propriedades antimicrobianas e de adesão contra E. coli e citotoxicidade do DLC utilizando queratinócitos humanos (HaCaT). Além disso, também avaliamos a capacidade para impedir a migração de E. coli na interface do implante hexágono externo. Uma técnica estéril foi utilizada para a reação em cadeia da polimerase semi-quantitativa (PCR semi-quantitativo). As superfícies mostraram uma ligeira diminuição da viabilidade celular (p<0,05), enquanto a ELS, R a , adesão bacteriana, testes antimicrobianos e de infiltração não apresentaram diferenças estatisticamente significativas (p>0,05). Concluiu-se que o DLC demonstrou ser um material biocompatível levemente citotóxico que não mostra alterações na Ra , ELS, adesão bacteriana ou propriedades antimicrobianas e não inibiu a infiltração de E. coli na interface abutment-implante dentário.

Analyses of Biofilm on Implant Abutment Surfaces Coating with Diamond-Like Carbon and Biocompatibility.

The aim of this study was to evaluate the surface free energy (SFE), wetting and surface properties as well as antimicrobial, adhesion and biocompatibility properties of diamond-like carbon (DLC)-coated surfaces. In addition, the leakage of Escherichia coli through the abutment-dental implant interface was also calculated. SFE was calculated from contact angle values; R a was measured before and after DLC coating. Antimicrobial and adhesion properties against E. coli and cytotoxicity of DLC with human keratinocytes (HaCaT) were evaluated. Further, the ability of DLC-coated surfaces to prevent the migration of E. coli into the external hexagonal implant interface was also evaluated. A sterile technique was used for the semi-quantitative polymerase chain reaction (semi-quantitative PCR). The surfaces showed slight decreases in cell viability (p<0.05), while the SFE, R a, bacterial adhesion, antimicrobial, and bacterial infiltration tests showed no statistically significant differences (p>0.05). It was concluded that DLC was shown to be a biocompatible material with mild cytotoxicity that did not show changes in R a, SFE, bacterial adhesion or antimicrobial properties and did not inhibit the infiltration of E. coli into the abutment-dental implant interface.