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1.
ACS Appl Mater Interfaces ; 13(1): 1524-1534, 2021 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-33378153

RESUMO

This study reports a simple and practical method to introduce antimicrobial and biofilm-controlling functions into hydroxyl- or amino-containing polymers such as cellulose using compounds derived from widely used reactive dyes. Two dichloro-s-triazine-based dyes, reactive blue 4 and sodium 4-(4,6-dichloro-1,3,5-triazinylamino)-benzenesulfonate (a colorless reactive "dye"), were covalently attached to cellulose at room temperature by replacing one chloride on the dyes with the hydroxyl groups on cellulose followed by hydrolysis under alkaline conditions to transform the remaining chloride into hydroxyl groups. The chemical reactions were confirmed by FT-IR studies, energy-dispersive X-ray spectroscopy, water contact angle measurement, and zeta potential analysis. The resulting cellulose provided powerful antimicrobial activities against Staphylococcus epidermidis (S. epidermidis, ATCC 35984, Gram-positive bacteria), Escherichia coli (E. coli, ATCC 15597, Gram-negative bacteria), and Candida albicans (C. albicans, ATCC 10231, yeast) and effectively prevented the formation of bacterial or fungal biofilms. The minimum inhibition concentrations of the hydrolyzed dyes were similar to that of phenol. In the zone of inhibition studies using phenolic compounds as positive controls, the hydrolyzed dyes and their model compound cyanuric acid demonstrated antimicrobial functions, suggesting that the antimicrobial activities were associated with the phenol-like hydroxyl groups on the triazine rings. Antimicrobial mechanism investigation indicated that the phenol-like structures on the dyed cellulose caused microbial lysis and leakage of intracellular components. The antimicrobial functions were durable upon repeated washing, and the dyed cellulose showed outstanding biocompatibility toward mammalian cells.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Celulose/análogos & derivados , Celulose/farmacologia , Corantes/química , Triazinas/química , Antibacterianos/química , Antifúngicos/química , Benzenossulfonatos/química , Biofilmes/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Candida albicans/fisiologia , Fibra de Algodão , Escherichia coli/efeitos dos fármacos , Escherichia coli/fisiologia , Testes de Sensibilidade Microbiana , Staphylococcus epidermidis/efeitos dos fármacos , Staphylococcus epidermidis/fisiologia
2.
Colloids Surf B Biointerfaces ; 134: 370-6, 2015 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-26222405

RESUMO

In order to evaluate the anti-infective efficacy of the titanium implant materials, two co-culture systems, a low-bacteria/osteoblast (L-B) and a high-bacteria/osteoblast system (H-B), were established. Untreated (UN-Ti), sulfuric acid-treated (SA-Ti), and chitosan immobilized titanium (SA-CS-Ti) materials were developed and evaluated. Bacteria and osteoblast behaviors, including initial attachment (evaluated at 30 mins), adhesion (evaluated at 4 h), and osteoblast spreading on each material surface were evaluated using quantification assays, scanning electron microscopy (SEM), and confocal microscopy. Quantification analysis at 30 mins showed significantly higher number of osteoblast present on SA-CS-Ti in both L-B (10,083 ± 2626) and H-B (23,592 ± 2233) than those on the UN-Ti (p<0.05). SEM observation and confocal microscopy results showed more surface area was occupied by adhered osteoblasts on SA-CS-Ti than UN-Ti and SA-Ti in both co-culture systems at 30 mins. At all time points, SA-CS-Ti had the lowest level of bacterial adhesion compared to UN-Ti and SA-Ti in both co-culture systems. A significantly (p<0.05) lower number of bacteria were recovered from SA-CS-Ti (2233 ± 681) in the H-B system compared to UN-Ti (5367 ± 1662) and SA-Ti (4533 ± 680) at 4h. Quantitative and qualitative co-culture results show the great potential of chitosan immobilization onto implant materials to prevent implant-associated infections.


Assuntos
Aderência Bacteriana , Adesão Celular , Quitosana , Osteoblastos/química , Staphylococcus aureus/fisiologia , Titânio , Materiais Biocompatíveis , Linhagem Celular , Técnicas de Cocultura , Microscopia Eletrônica de Varredura , Propriedades de Superfície
3.
Colloids Surf B Biointerfaces ; 122: 126-133, 2014 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-25033432

RESUMO

We have covalently immobilized chitosan onto a titanium (Ti) surface to manage implant-related infection and poor osseointegration, two of the major complications of orthopedic implants. The Ti surface was first treated with sulfuric acid (SA) and then covalently grafted with chitosan. Surface roughness, contact angle and surface zeta potential of the samples were markedly increased by the sulfuric acid treatment and the subsequent chitosan immobilization. The chitosan-immobilized Ti (SA-CS-Ti) showed two novel antimicrobial roles: it (a) prevented the invasion and internalization of bacteria into the osteoblast-like cells, and (b) significantly increased the susceptibility of adherent bacteria to antibiotics. In addition, the sulfuric acid-treated Ti (SA-Ti) and SA-CS-Ti led to significantly increased (P<0.05) osteoblast-like cell attachment, enhanced cell proliferation, and better osteogenic differentiation and mineralization of osteoblast-like cells.


Assuntos
Anti-Infecciosos/farmacologia , Quitosana/farmacologia , Osteogênese/efeitos dos fármacos , Titânio/química , Fosfatase Alcalina/metabolismo , Adesão Celular , Linhagem Celular , Proliferação de Células , Quitosana/química , Humanos , Osteoblastos/citologia , Osteoblastos/enzimologia , Propriedades de Superfície
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