Biomedical Functional Materials Research Articles

聚乙烯醇/壳聚糖复合水凝胶的物理化学性质

The physical properties such as the equilibrium water content, the melting enthalpy, the isothermal swelling kinetics and the non-isothermal dehydration kinetics of the composite hydrogels of poly(vinyl alcohol) (PVA) and chitosan (CS) were determined in this work. The influence of the composition and preparation parameters of the hydrogels on these properties was discussed. The results indicate that, PVA/CS composite hydrogel have a proper network structure to support water, and to work as an artificial cartilage material. Combining CS and PVA leads the crystallinity of gel to be weakened, but the interaction between water and gel scaffold to be enhanced. Though the mechanical tensile strength was lowered, but the biocompatibility and the degradation capacity of the gel were optimized. As a class of biomedical functional materials, PVA/CS hydrogel has a great potential application in cartilage scaffold. And as a model system of theoretical research, it promotes the application of thermodynamics in biomedical functional materials.

Gold Nanoparticle Localization at the Core Surface by Using Thermosensitive Core−Shell Particles as a Template

We report novel thermosensitive hybrid core-shell particles via in situ gold nanoparticle formation using thermosensitive core-shell particles as a template. This method for the in situ synthesis of gold nanoparticles with microgel interiors offers the advantage of eliminating or significantly reducing particle aggregation. In addition, by using thermosensitive microgel structures in which the shell has thermosensitive and gel properties in water--whereas the core itself is a water-insoluble polymer--we were able to synthesize the gold nanoparticles only at the surface of the core, which had reactive sites to bind metal ions. After the gold nanoparticles were synthesized, electroless gold plating was carried out to control the thickness of the gold nanoshells. The dispersions of the obtained hybrid particles were characterized by dynamic light scattering and UV-vis absorption spectroscopy, and the dried particles were also observed by electron microscopy. Adaptation of the technique shown here will create a number of applications as optical, electronic, and biomedical functional materials.