Biomaterials Lab 1 PPT Fall 2024 PDF

Biomaterials - ENGR-UH 4810 Fall 2024 Professor: Jeremy Teo Instructor: Shafiya Sabah 1  Biomaterials Lab Biomaterials lab: 30 % of total grade Activity Detail Gra...

Biomaterials - ENGR-UH 4810 Fall 2024 Professor: Jeremy Teo Instructor: Shafiya Sabah 1  Biomaterials Lab Biomaterials lab: 30 % of total grade Activity Detail Grade Percentage Lab Report 10 % Lab Quiz 1 10 % Lab Quiz 2 10 % 2  Requirements: ✓ Complete Mandatory online safety training Lab safety: Personal Protective Equipment (PPE) ✓ Laboratory coats ✓ Protective gloves ✓ Safety goggles ✓ Long pants ✓ Closed toe shoes 3  Hazard symbols: Corrosive Skin and Eye Flammable Biohazard sign chemical irritant 4  Hazard symbols: Toxic Harmful to Health hazard: Explosive environment - carcinogen - organ toxicity 5 Lab 1: Surface Wettability Characterization 6  Biomaterial surface wettability ▪ A biomaterial is defined as any substance, whether natural or synthetic, that can be used in the body to treat, support, or replace tissues, organs, or body functions. ▪ The performance of a biomaterial is typically evaluated by its "biocompatibility", which measures how well it integrates within a biological system. ▪ The surface of the biomaterial is the first component that comes into contact with the biological cells or fluids. ▪ Surface characteristics of the biomaterial such as wettability, topography and surface energy influence its biocompatibility. 7  Biomaterial surface wettability ▪ The term "wettability" refers to the ease with which a fluid spreads across a solid surface. ▪ Water wets different materials differently, it spreads out on hydrophilic surfaces while it forms droplet or beads on hydrophobic surfaces. ▪ The wettability of biomaterial surfaces can affect protein adsorption and cellular response. Studies have shown that cells adhere better to moderately wettable surfaces in comparison to hydrophobic surfaces. 8  Surface modification techniques ▪ Surface treatments use physical principles or chemical reactions to alter the surface composition. ▪ An ideal surface treatment should have the following characteristics: ✓ Thin (to minimize effects on bulk properties) ✓ Resistant to delamination ✓ Simple and robust (promote commercialization) 9  Water contact angle ▪ Wettability of biomaterials in vitro is evaluated through contact angle measurements. ▪ A drop of liquid when dispensed on to a solid surface will lead to formation of an angle at the intersection of Liquid, Vapor and Solid boundary. The equilibrium at three phase contact is given by Young’s equation: 𝛾𝑆𝑉 − 𝛾𝑆𝐿 − 𝛾𝐿𝑉 𝑐𝑜𝑠𝜃 = 0 where 𝛾𝐿𝑉 (surface tension of the liquid) , 𝛾𝑆𝐿 (solid- liquid interfacial tension), 𝛾𝑆𝑉 (surface energy of the Contact angle for a liquid droplet solid) θ is the contact angle 10  Water contact angle ▪ A high water contact angle indicates low wettability or a hydrophobic surface. ▪ A low water contact angle indicates high wettability or a hydrophilic surface. (a) (b) Contact angle for (a) a hydrophobic surface and (b) a hydrophilic surface 11  Contact Angle Measuring Equipment Drop shape analyzer (Krüss DSA25S) 12  PDMS (Polydimethylsiloxane) ▪ A clear, non-toxic silicone (hydrophobic) polymer ▪ Exhibits excellent biocompatibility, thermal stability and flexibility ▪ It is widely used in the fabrication microfluidic chips, biosensors and as drug-delivery carriers. Mixture of PDMS base PDMS coated glass slides Contact angle on PDMS coated glass slides and curing agent (10:1) 13  APTES (3-Aminopropyl)triethoxysilane ▪ APTES is a silane reagent that can chemically modify a material’s surface. ▪ Creates a durable, functional layer that can introduce specific Skin and Eye chemical groups (like amines) increasing hydrophilicity. irritant 14  Plasma Treatment ▪ Plasma treatment is a physical surface modification technique that improves wettability. ▪ A gas or mixture of gases are introduced inside a sealed, low-pressure vacuum chamber. ▪ These gases are then energized by RF (radio frequency) power ▪ Purplish glow is observed. This indicates that plasma has been generated ▪ The activated ions in these gases are accelerated and start to vibrate. This vibration “scrubs” surfaces in the chamber clean of contaminants. Plasma treatment 15  Plasma Treatment 16  Plasma Treatment Harrick Plasma cleaner 17