RESUMEN
Novel Cellulose (Cel) reinforced polyvinyl alcohol (PVA)-Silica (Si) composite which has good stability and in vitro degradation was prepared by lyophilization technique and implanted using N(3+) ions of energy 24keV in the fluences of 1×10(15), 5×10(15) and 1×10(16)ions/cm(2). SEM analysis revealed the formation of microstructures, and improved the surface roughness on ion implantation. In addition to these structural changes, the implantation significantly modified the luminescent, thermal and mechanical properties of the samples. The elastic modulus of the implanted samples has increased by about 50 times compared to the pristine which confirms that the stiffness of the sample surface has increased remarkably on ion implantation. The photoluminescence of the native cellulose has improved greatly due to defect site, dangling bonds and hydrogen passivation. Electric conductivity of the ion implanted samples was improved by about 25%. Hence, low energy ion implantation tunes the mechanical property, surface roughness and further induces the formation of nano structures. MG63 cells seeded onto the scaffolds reveals that with the increase in implantation fluence, the cell attachment, viability and proliferation have improved greatly compared to pristine. The enhancement of cell growth of about 59% was observed in the implanted samples compared to pristine. These properties will enable the scaffolds to be ideal for bone tissue engineering and imaging applications.
Asunto(s)
Celulosa/química , Alcohol Polivinílico/química , Dióxido de Silicio/química , Andamios del Tejido/química , Materiales Biocompatibles/química , Adhesión Celular , Línea Celular , Módulo de Elasticidad , Conductividad Eléctrica , Gossypium/química , Humanos , Iones/química , Luminiscencia , Sustancias Luminiscentes/química , Porosidad , Propiedades de SuperficieRESUMEN
Biodegradable, antimicrobial composite of various silver ion concentrations was synthesized using zeta potential and isoelectric point measurements, for a controlled release of silver ions, and in addition to assess the effect of protein adsorption with the increase of the silver ion concentration. The interaction between hydroxyapatite (HAp) and silver incorporated hydroxyapatite (AgHAp) with gelatin was increased by optimally adjusting the zeta potential and isoelectric point of the ceramic (HAp and AgHAp), and bio-polymer individually. The electrostatic interactions between the ceramic and biopolymer were confirmed, through shifts in N-H stretching, decrease in the swelling ratio, and increase in the degradation temperature observed by the derivative thermo-gravimetric analysis (DTG). These results substantiate that, the zeta potential is a novel tool to increase the ceramic-biopolymer interaction. Increasing electrostatic interaction between the biopolymer and ceramic, decreases the release of silver ions in the simulated body fluid, due to the controlled degradation of the biopolymer. The isoelectric point decreases with the increase of the silver ion concentration, which evidenced the change in the net surface charge. With the increase of the silver ion concentration, the protein adsorption decreases due to an increase in hydrophilic character of the composite. This study examines the minimum concentration of silver ion essential for maximum protein adsorption, antimicrobial and hemocompatibility. This study provides a novel route to control the release of silver ions by enhancing the ceramic-polymer interaction and estimate the silver ion concentration suitable for protein adsorption. The prepared composite is nontoxic, degradable, and antimicrobial, with the controlled release of silver ions in the simulated body fluid.
Asunto(s)
Materiales Biocompatibles/química , Iones/química , Compuestos de Plata/química , Plata/química , Adsorción , Antiinfecciosos/química , Antiinfecciosos/farmacología , Materiales Biocompatibles/farmacología , Líquidos Corporales/efectos de los fármacos , Cerámica/química , Cerámica/farmacología , Durapatita/química , Durapatita/farmacología , Gelatina/química , Bacterias Gramnegativas/efectos de los fármacos , Humanos , Iones/farmacología , Ensayo de Materiales/métodos , Polímeros/química , Plata/farmacología , Compuestos de Plata/farmacología , Electricidad Estática , TemperaturaRESUMEN
Biodegradable laminated polymer composites of agarose (A), gelatin (G) and hydroxyapatite (HAp) having 3D network of interconnected pores (1-500 µm) were fabricated without using cross linking agents. The incorporation of HAp to A, G and AG had considerable influence on the swelling behaviour, drug release and haemolytic activity. A-HAp scaffolds demonstrated interconnected porosity with extended drug release. G-HAp scaffolds possessed enhanced mechanical property. AG-HAp scaffolds exhibited extended drug delivery, haemocompatibility and efficacy against Gram positive bacteria compared with G-HAp. Hence, AG-HAp composites could be used us a scaffold for tissue engineering and drug delivery system. This method provides non toxic, versatile and cost effective biodegradable scaffolds which could be used for various biomedical applications.