Engineering Commons^™

Calcium Phosphate-Based Resorbable Biomaterials For Bone Regeneration, Daniel O. Costa

Electronic Thesis and Dissertation Repository

Bone defects are a prevalent problem in orthopedics and dentistry. Calcium phosphate-based coatings and nanocomposites offer unique solutions towards producing scaffolds with suitable physical, mechanical and biological properties for bone regeneration.

We developed a novel method to synthesize hydroxyapatite (HA) particles with high aspect ratio using sol-gel chemistry and hydrothermal treatment. We obtained tunable pure-phase carbonated-HA in the form of micro/nanorods and nanowires (diameters 25-800 nm). To mimic the structure of bone, HA nanowires were homogenously mixed within poly(ε-caprolactone) (PCL) to produce nanocomposites with improved mechanical properties as determined by uniaxial tensile testing.

Surface chemistry and topography of biomaterials play …

Development Of A Novel Handheld Device For Active Compensation Of Physiological Tremor, Abhijit Saxena

Electronic Thesis and Dissertation Repository

In microsurgery, the human hand imposes certain limitations in accurately positioning the tip of a device such as scalpel. Any errors in the motion of the hand make microsurgical procedures difficult and involuntary motions such as hand tremors can make some procedures significantly difficult to perform. This is particularly true in the case of vitreoretinal microsurgery. The most familiar source of involuntary motion is physiological tremor. Real-time compensation of tremor is, therefore, necessary to assist surgeons to precisely position and manipulate the tool-tip to accurately perform a microsurgery. In this thesis, a novel handheld device (AID) is described for compensation …

Hydrogel-Based Nanocomposites And Laser-Assisted Surface Modification For Biomedical Application, Pei Yin

Electronic Thesis and Dissertation Repository

Hydrogels can be used in contact lens, wound dressing, drug delivery and tissue scaffolds due to their good biocompatibility. However, the poor mechanical properties and non-specific protein adsorption of hydrogels limit their applications. The adverse effects of protein adsorption in hydrogels include biofouling, inflammation, or even body rejection. In this project, two different hydrogel materials, co-polymer 2-hydroxyethyl methacrylate with a low amount of 2-aminoethyl methacrylate, p(HEMA-co-AEMA) and silicone hydrogel were fabricated by photo-polymerization; the former has hydrophilic surface and the latter is hydrophobic. The silica (SiO₂) nanoparticle-loaded hydrogels have been developed by using in situ polymerization. The dispersion …