Biomedical subjects

Jonny J Blaker

Publications and source records attributed to Jonny J Blaker.

4 recordsLinked to original sources

PubMed2005

Thermal Characterizations of silver-containing bioactive glass-coated Sutures.

This study utilized and compared a number of thermal analysis methods to characterize the thermal properties of commercial sutures with and without antimicrobial coatings of silver-doped bioactive glass (AgBG) interlocking particulates. The effect of a slurry dipping technique used to coat resorbable Vicryl (polyglactin 910) and non-resorbable Mersilk surgical sutures with AgBG was investigated using conventional differential scanning calorimetry (DSC), high speed calorimetry (or HYPERDSC), and modulated temperature DSC (MTDSC). These methods were compared in terms of their ability to resolve the thermal transitions of the types of suture materials. Differential thermal analysis (DTA) and thermogravimetric analysis (TGA) were used to verify the thermal degradation temperatures of these materials and to quantify the AgBG coatings on the sutures. The use of complementary thermal analysis techniques enabled the understanding of the effect of the AgBG coating technique on the morphological properties of the sutures. The slurry dipping technique had no significant effect on the thermal transitions of both types of materials. The use of high speed calorimetry through DSC offered better resolution for the transitions that appeared to be weak through conventional heating regimes, and was able to separate broad double transitions. Furthermore, it was shown not to compromise either the melting temperature or the enthalpy of melting. Therefore this method allows for the accurate determination of thermal transitions through much shorter experimental times thus allowing for an increased sample throughput. The combined DTA and TGA indicated that a greater AgBG coating was obtained in the case of the Mersilk sutures.

Coated Materials, Biocompatible↗

PubMed2005

Bioactive composite materials for tissue engineering scaffolds.

Synthetic bioactive and bioresorbable composite materials are becoming increasingly important as scaffolds for tissue engineering. Next-generation biomaterials should combine bioactive and bioresorbable properties to activate in vivo mechanisms of tissue regeneration, stimulating the body to heal itself and leading to replacement of the scaffold by the regenerating tissue. Certain bioactive ceramics such as tricalcium phosphate and hydroxyapatite as well as bioactive glasses, such as 45S5 Bioglass, react with physiologic fluids to form tenacious bonds with hard (and in some cases soft) tissue. However, these bioactive materials are relatively stiff, brittle and difficult to form into complex shapes. Conversely, synthetic bioresorbable polymers are easily fabricated into complex structures, yet they are too weak to meet the demands of surgery and the in vivo physiologic environment. Composites of tailored physical, biologic and mechanical properties as well as predictable degradation behavior can be produced combining bioresorbable polymers and bioactive inorganic phases. This review covers recent international research presenting the state-of-the-art development of these composite systems in terms of material constituents, fabrication technologies, structural and bioactive properties, as well as in vitro and in vivo characteristics for applications in tissue engineering and tissue regeneration. These materials may represent the effective optimal solution for tailored tissue engineering scaffolds, making tissue engineering a realistic clinical alternative in the near future.

Biocompatible Materials↗

PubMed2004

PDLLA/Bioglass composites for soft-tissue and hard-tissue engineering: an in vitro cell biology assessment.

The aim of this study was to examine the effect of increased content of 45S5 Bioglass (0-40 wt%) in poly(dl-lactic acid) (PDLLA) porous foams on the behaviour of MG-63 (human osteosarcoma cell line) and A549 cells (human lung carcinoma cell line). The ability of these cell lines to grow on bioactive composites was quantitatively investigated in order to assess the potentiality for their use in hard and soft-tissue engineering. Two hours after cell seeding, an increase of cell adhesion according to the increased content of Bioglass((R)) present in the foams for both cell types was observed. Cell proliferation studies performed over a period of 4 weeks showed a better aptitude of the A549 cells to proliferate on PDLLA foams containing 5 wt% Bioglass when compared to the proliferation on foams with 40 wt% Bioglass. A lower proliferation rate was obtained for cells on pure PDLLA. Scanning electron microscopy analysis showed for both cell types the presence of cells inside the porous structure of the foams. These results confirmed the biocompatibility of PDLLA/Bioglass composite foams and the positive effect of Bioglass on MG-63 cell behaviour and also showed for the first time the possibility for human lung epithelial type II cells to adhere and proliferate on these porous scaffolds. In addition, we describe a positive effect of 45S5 Bioglass on A549 cell behaviour in a dose-dependent manner, indicating the potential of using PDLLA/Bioglass composites with an optimal concentration of 45S5 Bioglass not only in bone tissue engineering but also in lung tissue engineering.

Biocompatible Materials↗

PubMed2004

In vitro attachment of Staphylococcus epidermidis to surgical sutures with and without Ag-containing bioactive glass coating.

The ability of a silver-doped bioactive glass (AgBG) coating to prevent bacterial colonization on surgical sutures was investigated in vitro. Bioactive glass powders, in the form of 45S5 Bioglass and AgBG, were used to coat Mersilk sutures using an optimized 'in house' slurry-dipping process. In vitro experiments were carried out using Staphylococcus epidermidis under both batch and flow conditions. While the traditional batch culture testing was used to determine the number of viable cells adhered to the surface, the flow-cell was used to visualize attachment and detachment over time. Under batch conditions of up to 180 min, statistically significant differences were observed in the colony forming units (CFU) per suture for both the coated and uncoated Mersilk sutures. The results showed that the AgBG coating had the greatest effect on limiting bacterial attachment (8 x 10(2) CFU) when compared to the 45S5 Bioglass coating (3.2 x 10(3) CFU) and the uncoated Mersilk (1.2 x 10(4) CFU). Also under flow conditions differences were seen between the coated and uncoated sutures. Therefore, this preliminary study has demonstrated the quantification and visualization of bacterial attachment onto sutures in order to compare the antibacterial properties of Ag-containing bioactive glass coatings. The bactericidal properties imparted by Ag-containing glass open new opportunities for use of the composite sutures in wound healing and body wall repair.

Bacterial Adhesion↗