RESUMO
The design and development of wound dressing with antioxidant and antibacterial properties to accelerate wound healing remain challenging. In this study, we synthesize a chitooligosaccharide-gentisic acid (COS-GSA) conjugate using the free-radical grafting method, and fabricate a poly(vinyl alcohol) (PVA)/chitosan (CH)/COS-GSA (PVA/CH/CG) hydrogel using a freeze-thaw method. We characterize the synthesized COS-GSA conjugates using through polyphenol assay, absorbance, and 1H NMR spectroscopy and evaluate their antioxidant properties. The COS-GSA conjugates are successfully synthesized and exhibit better antioxidant properties than pristine COSs. Subsequently, the fabricated hydrogel is characterized based on its morphological analysis, rheological properties, water contact angle, swelling, degradation, water retention properties, and COS-GSA release profiles. Finally, the biocompatibility of the fabricated hydrogel is evaluated on HDF and HaCaT cells through indirect and direct cytotoxicity. The PVA/CH/CG hydrogel exhibited significantly higher antioxidant properties (DPPH, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and hydrogen peroxide (H2O2) scavenging activities) and antibacterial activities (Staphylococcus aureus and Pseudomonas aeruginosa) compared to other fabricated hydrogels such as PVA, PVA/CH, and PVA/CH/COS (PVA/CH/C). These results provide evidence that PVA/CH/CG hydrogels with antioxidant, antibacterial, and non-cytotoxic properties have great potential for wound-dressing applications.
Assuntos
Quitosana , Quitosana/química , Antioxidantes/farmacologia , Álcool de Polivinil/química , Hidrogéis/química , Peróxido de Hidrogênio , Antibacterianos/farmacologia , Antibacterianos/química , Bandagens , Água , EtanolRESUMO
Micro-arrayed polydiacetylene (PDA) vesicles mixed with phospholipids on glass slides were prepared for label-free detection of Escherichia coli. When E. coli bound to its antibodies chemically attached to polydiacetylene, the fluorescence of the vesicles was dramatically increased. The insertion of dimyristoyl phosphatidylcholine (DMPC) in the vesicles drastically reduced the response time for the fluorescence changes. Vesicles with 20-30% DMPC provided optimal results for bacterial detection. Fourier transform infrared (FTIR) spectra analysis suggested that DMPC insertion decreased the strength of hydrogen bonding among the amide and carboxylic acid groups of the polydiacetylene vesicles. Reduced bonding strength resulted in less rigid structure of the polydiacetylene polymer, allowing more rapid detection upon molecular recognition.
Assuntos
Técnicas Biossensoriais/métodos , Dimiristoilfosfatidilcolina/química , Polímeros/química , Poli-Inos/química , Análise Serial de Proteínas , Amidas/química , Anticorpos/química , Reações Antígeno-Anticorpo , Técnicas Biossensoriais/instrumentação , Ácidos Carboxílicos/química , Escherichia coli/química , Fluorescência , Vidro/química , Ligação de Hidrogênio , Modelos Moleculares , Estrutura Molecular , Polímero Poliacetilênico , Salmonella typhimurium/química , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de SuperfícieRESUMO
We developed a simple and effective polydiacetylene-based, label-free multiplex DNA chip for the detection of various pathogenic microorganisms. A novel immobilization method of PDA vesicles on glass slides was exploited using α-cyclodextrin (α-CD). The surface topography of the efficiently immobilized PDA vesicles was confirmed using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Then, oligonucleotides complementary to rRNAs of three pathogenic bacteria were conjugated to the PDA vesicles. Finally, crude lysate of pathogenic bacteria was applied to the PDA biochip. The pathogenic bacteria were specifically detected by DNA-RNA hybridization in an hour. The new PDA sensor was effective in detecting multiple pathogenic bacteria easily and accurately without rigorous purification, amplification, and labeling of their genetic components.