The Modeling of Insulin Controlled Release Process From Fibrous Artificial Store

In the past, insulin was frequently administered by hypodermic injection, as liquids forms. To avoid problems incurred through the utilization of the injectable route of insulin administration, new dosage forms containing the insulin were introduced. Therefore, insulin delivery systems were developed to optimize the therapeutic properties of drug products and render them safer, more effective, and more reliable. The aim of this article is to present the modeling of the controlled releasing process of insulin from a fibrous artificial store. The release of insulin has been evaluated in both a physiological solution and blood serum in vitro and on experimental animals (mice) in vivo. On the basis of experimental results a mathematical model of diffusion-mediated release of insulin from cation-exchange fiber has been developed and presented in this paper

The use of porous calcium phosphate scaffolds with transforming growth factor beta 1 as an onlay bone graft substitute.

Item does not contain fulltextOBJECTIVES: Autogeneous bone grafting is regarded to be the golden standard for onlay grafts, but it requires a harvesting procedure and the remodeling pattern over time is unpredictable. New materials are constantly being sought to overcome these problems. An in vivo experiment was carried out to evaluate whether (1) porous calcium phosphate cement is a suitable biomaterial for onlay bone grafting, and (2) the addition of transforming growth factor beta 1 (TGF-beta1) accelerates de novo bone formation inside the cement porosity. MATERIAL AND METHODS: A carrier of porous calcium phosphate cement (Calcibon) was designed and 16 rats received one preshaped implant each. In 8 out of 16 implants 0.75 mug TGF-beta1 was applied. The animals were killed after 4 weeks and the characteristics of tissue ingrowth into the onlay graft were evaluated. RESULTS: Histologic and quantitative histomorphometrical measurements demonstrated osteoid-like tissue formation in both experimental groups. The addition of TGF-beta1 did not induce significantly more osteoid-like tissue formation. On the other hand, in TGF-beta-loaded implants, a higher number of pores contained an inflammatory infiltrate. CONCLUSION: This study indicated that porous calcium phosphate cement is a promising material for clinical situations where bone formation has to be supported