Preparation, characteristics and assessment of a novel gelatin-chitosan sponge scaffold as skin tissue engineering material.

In order to develop a skin tissue engineering material for wound dressing application, a novel gelatin-chitosan sponge scaffold was designed and studied. The effect of chitosan and gelatin ratio on the morphology, pore size, porosity, water uptake capacity, water retention capacity and the degradation behavior were evaluated. Biocompatibility was investigated by both MTT method and AO/EB staining method. Antibacterial assessment and in vivo pharmacodynamic was also studied to evaluate the potential for wound healing. Results showed the sponge scaffold have uniform porous structure with pore size range between 120 and 140 µm, high porosity (>90%), high water uptake capacity (>1500%), high water retention capacity (>400%), and degradation percent in 28 days between 38.3 and 53.9%. Biocompatibility results showed that the activity of cells could not be affected by the nature of the sponge and it was suitable for cell adhesion and proliferation for 21 days. In vivo evaluation indicated that the sponge scaffold could offer effective support and attachment to cells for skin wound healing. In conclusion, the developed sponge scaffold was a potential skin tissue engineering material with appropriate physical properties and good biocompatibility.

In vivo assessment of novel furosemide gastro-mucoadhesive delivery system based on a kind of anion ion-exchange fiber.

A novel gastro-mucoadhesive delivery system based on a kind of anion ion-exchange fiber has been developed. Furosemide (FM), which is site-specifically absorbed from the upper gastrointestinal (GI) tract, was used as model drug. A novel-modified dissolution system, which can also be called "flow through diffusion cell," was used to study the drug release from the drug fibers. The GI transit studies of the FM fiber complexes in rats and gamma imaging studies in volunteers were carried out to evaluate the gastro-mucoadhesive behavior of the fiber. The pharmacokinetic profile and parameters of the FM suspension and FM fiber in fasted and fed rats were measured, respectively. Studies on rats and volunteers provided evidence for the validity of the hypothesis that the drug fiber provided better gastro-mucoadhesive properties in vivo.