Showing papers in "Biomaterials in 1994"

TL;DR: This review article focuses on the surface modification of polymers by grafting techniques, which have long been known in polymer chemistry but are not yet widely applied to biomaterials.

TL;DR: A qualitative model has been proposed to account for the degradation of aliphatic polyesters derived from lactic and glycolic acids, based on diffusion-reaction phenomena combined with the well-known autocatalytic effect of carboxylic chain ends.

TL;DR: The water entry even after 1 h was very close to its plateau value for all prewet polymers tested, which has been useful in uniformly seeding three-dimensional biodegradable polymer substrates for cell and tissue culture.

TL;DR: A large number of research groups have studied the interaction of biomedical materials with cultured cells to improve their tissue compatibility when the materials are implanted as substitutes for organs, skin, bone, etc.

TL;DR: The present investigation demonstrates that chitosan has an in vitro stimulatory effect on both macrophage nitric oxide (NO) production and chemotaxis and strengthens the hypothesis that in vivo experiments strengthen this hypothesis.

TL;DR: These studies show that a high degree of bone contact and bone formation can be achieved with titanium implants which are modified with respect to oxide thickness and surface topography, and it appears that a reduction of surface roughness may influence the rate of bone formation in rabbit cortical bone.

TL;DR: A novel modified chitosan carrying covalently linked imidazole groups was used to stimulate bone formation in an animal model and neoformed tissue occluded the surgical hole and assumed a trabecular structure in the peripheral area of the lesion, while looking like a mineralization nodule in the central part in association with a fibrous component.

TL;DR: The presented experimental tissue culture technique offers a novel concept for the in vitro formation of vital cartilage implants for reconstructive surgery or treatment of destructive joint diseases and possibly for theIn vitro engineering of human tissues in general, with applications in drug testing and replacement of animal experiments.

TL;DR: Examination of blood-biomaterial interactions indicates that relevant features are protein adsorption, platelet reactions, intrinsic coagulation, fibrinolytic activity, erythrocytes, leucocytes and complement activation.

TL;DR: To varying degrees, all titanium surfaces indicated activation of the intrinsic pathway of coagulation as determined by their kallikrein formation in plasma.

TL;DR: This study shows that a cationic hydrogel, precipitated chitosan, supports attachment and spreading of fibroblasts when used as a matrix in the lumen of a PAN/PVC macrocapsule.

TL;DR: An ion beam dynamic mixing (IBDM) method was used to produce thin hydroxyapatite coatings on titanium substrates, indicating the high tensile bond strengths from the as-coated films.

TL;DR: Biodegradable polymers composed of polyglycolic acid and poly-L-lactic acid and their co-polymers were used to produce templates to transplant cells and promote regeneration of structural cartilage to help in the process of neomorphogenesis of cartilage.

TL;DR: With the exception of Young's modulus, all mechanical properties of the tested materials were significantly improved when a silanized hydroxyapatite filler had been used.

TL;DR: Ceramics containing alpha-tricalcium phosphate evoked bone formation in the pores of the ceramics in dogs for 1, 3, 5 and 7 months, and the amount of bone was similar at the different time periods.

TL;DR: Results show that for human bone-derived cells, the attachment and spreading of cells onto SS, Ti and Al2O3 as well as PET during the first 90 min of a cell culture attachment assay are a function of adsorption of serum Vn onto the surface.

TL;DR: In general, all types of implants showed similar bone response, some bone contact and several remodelling lacunae along the surfaces after long-term implantation.

TL;DR: Those stems treated thermally were found to have significantly lower metal ion release and improved dissolution behaviour, associated with a change in the surface oxide structure from mixed titanium oxides to a more stable rutile structure.

TL;DR: The results of this preliminary study indicate that, with regard to early bone formation, amorphous hydroxyapatite coatings seem to be beneficial over highly crystalline coatings, but further experiments should be performed to give conclusive data on (i) the statistical significance of the differences in bone apposition rate, and (ii) the long-term behaviour of bothAmorphous and highly crystallines coatings in bone and their relation to implant performance.

TL;DR: The results discussed indicate that the tensile strength of reconstituted collagen fibres is optimized by cross-linking for 5 d at 110 degrees C.

TL;DR: A new glucose-responsive insulin delivery system composed of phenylboronic acid (PBA) groups was prepared and investigated and it is demonstrated that the PBA gel beads release G-Ins in response to glucose concentration.

TL;DR: Observations tend to suggest that the carboxylic groups in the beta-glucoronic acid unit are the activation centre of this enzyme and the total blockage of these groups can restrict the cleavage of beta (1-->4) glycoside bonds by this enzyme.

TL;DR: The permeability study showed that the water content as well as the mesh size had an influence on the diffusion of low molecular weight glucose and insulin, indicating that diffusion occurs primarily through the water hydrating the polymer network.

TL;DR: The structure and mechanical properties of collagen fibre dispersions were studied by dynamic rheological measurements and by polarized microscopy and found to possess more rigid fibres and stronger inter-fibre attractive forces at higher pHs.

TL;DR: Calcium phosphate coatings produced using the ion beam sputter deposition process are amorphous and a series of different post-deposition heat treatments were conducted to produce crystalline HA-type coatings, suggesting the formation of a new phase.

TL;DR: Methylpyrrolidinone chitosan (MPC) was investigated as a carrier material for basic fibroblast growth factor (bFGF), a combination intended for the treatment of wound healing deficiencies.

TL;DR: Silver-coated and uncoated materials displayed comparable signs of inflammation and tissue reaction in a long-term implantation test using rabbits.

TL;DR: It can be concluded that the HA coating was an effective method for improving bone formation and ingrowth in the porous implants.

TL;DR: Hydroxyapatite composite resin is a promising material which possesses superior mechanical strength and the biological property of achieving direct contact with bone in a new type of bioactive bone cement.