Answer Happy

Briefly describe the type of experimental study design used
what were your input variables and response variables?
Describe strategies or steps used to avoid bias.
a. State goal of experiment and hypotheses tested. b. Provide a brief discussion on data collected, i.e. if there were unusual values and or variability in any of the measurements and what may have accounted/contributed to variability, outliers or been sources of error, what can be said about meeting normality criteria. Was there any impact of these issues that prevented/help justify Normality criteria assessment? c. In comparing cleaned/polished stainless steel to clean silicone elastomer, what was the p-value and how did you interpret the p-value in determining if there is a difference or not between the two materials? Does the 95% CI for the difference between the two means indicate if there is a difference between the two materials? Was one material more hydrophilic or hydrophobic than the other? If there is a difference, what would this imply about how proteins/cells would or would not adsorb or attach to the material?d. Based on results what implant applications might these materials be useful for and why?
a. State goal of experiment and hypotheses tested. b. Provide a brief discussion on data collected, i.e. if there were unusual values and or variability in any of the measurements and what may have accounted/contributed to variability, outliers or been sources of error, what can be said about meeting normality criteria. Was there any impact of these issues that prevented/help justify Normality criteria assessment? c. In comparing cleaned/polished stainless steel to clean silicone elastomer, what was the p-value and how did you interpret the p-value in determining if there is a difference or not between the two materials? Does the 95% CI for the difference between the two means indicate if there is a difference between the two materials? Was one material more hydrophilic or hydrophobic than the other? If there is a difference, what would this imply about how proteins/cells would or would not adsorb or attach to the material?d. Based on results what implant applications might these materials be useful for and why?
a. State goal of experiment and hypotheses tested.
b. Provide a brief discussion on data collected, i.e. if there were unusual values and or variability in any of the measurements and what may have accounted/contributed to variability, outliers or been sources of error, what can be said about meeting normality criteria. Was there any impact of these issues that prevented/help justify Normality criteria assessment?
c. In comparing cleaned/polished stainless steel to clean silicone elastomer, what was the p-value and how did you interpret the p-value in determining if there is a difference or not between the two materials? Does the 95% CI for the difference between the two means indicate if there is a difference between the two materials? Was one material more hydrophilic or hydrophobic than the other? If there is a difference, what would this imply about how proteins/cells would or would not adsorb or attach to the material?
d. Based on results what implant applications might these materials be useful for and why?
Medical devices such as a total hip replacement, vascular stents, ligaments and implantable sensors, when implanted participate in a wide array of interactions with cells and tissues including inflammation/clotting, healing, integration into tissues or fibrous encapsulation (scarring). One of the most important aspects is how cells and proteins adsorb to surfaces, since it is the surface of the implanted material that makes first contact with patient cells and proteins. The proteins from interstitial fluids and blood typically interact first, quickly followed by cells. It is this interaction between the implant surface and body fluids and cells that is extremely important to the ultimate clinical performance of the devices. In some applications, protein and cell adsorption may lead to excessive inflammation and unwanted tissue responses such as fibrosis or scar tissue. For example, when epithelial/smooth muscle cells attach and proliferate on cardiovascular stents, devices used to open blood vessels due to narrowing or the arteries, they can lead to a re- narrowing of the artery, a condition known as re-stenosis, Figure 1. In other applications, protein and cell attachment to surfaces may lead to high cell attachment with minimal inflammation. For example, orthopedic implants are commonly made of titanium to encourage osteoblast cell attachment which ultimately leads to a mechanical interlock between the implant and bone, aka osseointegration, Figure 2. The interaction of materials with host fluids and cells is dependent in part on the hydrophilic (water-loving) vs hydrophobic (water- repellant) properties of the implant surface. Hydrophilic surfaces generally are more favorable to adsorption of proteins and cells, whereas hydrophobic surfaces are generally less favorable to adsorption of proteins and cells. In this study the angle that a drop of water makes with the surface of two implant material surfaces is measured. If the water beads up and has a contact angle greater than 90, it is said to be hydrophobic, whereas if the drop spreads out the contact angle will be less than 90 and the surface is considered hydrophilic (Figure 3). Figure 1 - Two different types of stents. The standard stent (A) has a lot of cell attachment while the heparin coated stent (B) is designed to minimize cell attachment. Ian Menown, MD et al. 2005.
In this study the angle that a drop of water makes with the surface of two implant material surfaces is measured. If the water beads up and has a contact angle greater than 90, it is said to be hydrophobic, whereas if the drop spreads out, the contact angle will be less than 90 and the surface is considered hydrophilic (Figure 3). Figure 1 - Two different types of stents. The standard stent (A) has a lot of cell attachment while the heparin coated stent(B) is designed to minimize cell attachment. Ian Menown, MD et al. 2005. Figure 2 - Bone in close apposition to titanium pin in a rabbit model (Bumgardner et al., Implant Dent, 2007). Hydrogh Figure 3: Schematic of water contact angle for hydrophobic and hydrophilic surfaces. DOO DOO contactangle adreses good Materials: The two implant materials used in this lab are 316L stainless steel and silicone elastomer. The 316L stainless steel (SS) is widely used in orthopedie implant applications including bone plates and screws as well as in cardiovascular stent applications. Silicone elastomer is used in a variety of cardiovascular applications including artificial heart valves, medical tubing, cerebral shunts, implantable sensors, and in finger joints due in part to its hydrophobicity and high flexibility. Each group must measure one specimen of each material.
Group 00 01 OZ 10 11 12 55 - Left 55ght 29.9 29.9 588 56.3 38.5 38.5 481 481 458 45.8 415 35.6 SE.Left SERht 107.3 107.3 125.3 1253 118.7 118.7 121.7 1217 1211 121.1 120.2 For each group, left and right angle measurements should be averaged In order to get a SINGLE water contact angle for 5 and a single angle for silicone elastomer 1211 55 stainless steel SE = silicone elastomer