By using the so-called “lag-time” method, we studied the effect of membrane thickness(h), initial drug concentration(Co) and flow rate(V) on the difusion coefficient(D) of model drug in membranes. The expe riment indica tes that D increases as hand vincrease; D Keeps constant when C0 changes; Un den the same condition, the D value of N-alkyl chitosan membrane is bigger than that of pure chitosan membrane.

Growth factors play an important role in cell adhesion and proliferation as well as in tissue regeneration. By incorporating growth factors into polymer scaffolds, controlled release of them can be performed. The release mechanism is varied with the incorporation methods. In this paper, the latest advances in the controlled release of growth factors by blending, hydrogel, microsphere embedding and chemical bonding are reviewed. The potential application of ultrafine fibric embedding in growth factor delivery is described as well.
Biocompatible Materials ; Blood Vessel Prosthesis ; Drug Delivery Systems ; methods ; Growth Substances ; pharmacokinetics ; Hydrogels ; Microspheres ; Tissue Engineering ; methods

The host inflammatory reaction is a normal response to injury and the presence of foreign substances. Macrophage is one of the principal cell types in controlling host inflammatory and immune processes; hence, its response to biomaterials has a direct impact on biocompatibility and stability of biomaterials in vivo. This review describes the interaction of macrophages with tissue engineering related biomaterials. The bulk physicochemical structure and surface performance of biomaterials could be designed to control macrophages behaviors (i. e. adhesion, activation, fusion, apoptosis) and host responses, resulting in improving biocompatibility of biomaterials.
Apoptosis ; physiology ; Biocompatible Materials ; chemistry ; metabolism ; Cell Adhesion ; physiology ; Foreign-Body Reaction ; immunology ; Humans ; Inflammation ; immunology ; Macrophage Activation ; Macrophages ; cytology ; physiology ; Prosthesis Implantation ; Tissue Engineering ; methods

Ultrafine poly (D, L-lactide) (PLA) fibers with diameter less than 200 nm produced by electrospinning were studied to obtain tissue restoration resembling extracellular matrix. Scanning electron microscopy was used to observe the fiber morphology. Results showed that the solvent was the critical factor to determine the formation of the electrospun PLA fibers. Compared with acetone, N,N-dimethylformamide (DMF) was a better solvent for PLA to electrospin. Entrance of an organic salt, triethylbenzylammonium chlorate, led to a great increase of the conductivity of PLA/DMF solutions, so that the average fiber diameter of the electrospun PLA fibers decreased dramatically from 500 nm to 100-200 nm. The addition of surfactant, Span-80, did not improve the fiber morphology but formed beaded fiber web.
Biocompatible Materials ; chemical synthesis ; chemistry ; Dimethylformamide ; chemistry ; Electricity ; Electrochemistry ; Fiber Optic Technology ; methods ; Microscopy, Electron, Scanning ; Polyesters ; chemistry ; Surface Tension

Elastin is a natural biomedical material of great potential. Being endowed with the special crosslinking and hydrophobic structure, elastin retains many good properties such as good elasticity, ductibility, biocompatibility, biodegradability and so on. Nowadays, elastin as a material, which is gradually attracting people' s attention in the biomedical materials field, has been used as tissue engineering scaffolds, derma substitutes and other biomedical materials. In this context, a systematic review on the characteristics of elastin as a biomedical material and on the actuality of its application is presented. Future developments of elastin in the field of biomedical applications are also discussed.
Biocompatible Materials ; Elastin ; chemistry ; physiology ; Humans ; Skin, Artificial ; Tissue Scaffolds

The construction of biologic functional surfaces of materials, from the visual angle of material science, is aimed to make the biomaterials adapted by tissues, and to endow them with dynamic conformity; moreover, from the view-point of clinical applications, it is the functional surface to join the environmental tissues with the implanted material, playing the role of artificial extracellular matrix (ECM). The architecture of biologic functional surface is very important in tissue engineering science. Here the primary concepts of biological surface science and the construction and application of biofunctional surfaces in tissue engineering are reviewed.
Biocompatible Materials ; chemistry ; Biomimetic Materials ; chemistry ; Cell Culture Techniques ; methods ; Extracellular Matrix ; chemistry ; Humans ; Surface Properties ; Tissue Engineering ; methods ; trends ; Tissue Scaffolds ; chemistry

The biosafety of gene delivery vectors has received much more attention in recent years. In this article, the biosafety of non-viral gene delivery vectors was mainly discussed. Recent developments in researches on toxicity, nano-effect, blood compatibility and immune response of non-viral gene delivery vectors were reviewed.
Cations ; chemistry ; Drug Delivery Systems ; methods ; Gene Transfer Techniques ; Genetic Therapy ; methods ; Genetic Vectors ; immunology ; pharmacokinetics ; toxicity ; Humans ; Nanoparticles ; chemistry