Chap.2 – 2.10 Surface modification of Biomaterials SOME IMPORTANT MODIFIED SURFACES Anti-fouling (nonfouling) surfaces (NFSs) - NFSs refer to surfaces that resist the adsorption of protein and/or adhesion of cells (protein-resistant surfaces and “stealth” surfaces) - Generally: hydrophilic surfaces are more likely to resist protein adsorption and hydrophobic surfaces usually will adsorb a monolayer of tightly adsorbed protein - NFSs are also important to reduce bacterial bio-films forming which can stimulate significant inflammatory reaction to the infected devices (in urinary catheters and endotracheal tubes, in vascular grafts, hip joint prostheses, heart valves and other long-term implants) c om - Used as blood-compatible materials (where they may resist fibrinogen adsorption and platelet attachment), implanted devices, urinary catheters, diagnostic assays biosensors, affinity separations, microchanel flow devices, intravenous syringes and tubing (It is important to noted that many of these uses involve in vivo implants or extracorporeal devices, and many others involve in vitro diagnostic assays, sensors…) - Examples: Blood compatible “PEO-like” films co *Usually coated on PET surfaces by plasma deposition ng •Surface containing PEG- poly(ethylene glycol) (-CH2CH2-O-)n n from to 15: oligome ethylene glycol (oEG) n from 15-3500 (M = 400- 100,000): PEG n greater than 100,000: PEO - poly(ethylene oxide) Advanced Program Biomedical Engineering – HUST, Vietnam ng th an du o Chap.2 – 2.10 Surface modification of Biomaterials “Teflon-like” films • Used as Blood-compatible materials, usually coated on Dacron cu u • Composition: CFx (00), and high cross-linking; (B) ordered chain structure with –CF3 surface groups, high F/C ratio, very low cross-linking and surface energy *Preparation by RF plasma deposition of C2F4 in H2 , composition is controlled by changing C2H4/H2 feed * Very hydrophobic, high protein retention CuuDuongThanCong.com Advanced Program Biomedical Engineering – HUST, Vietnam https://fb.com/tailieudientucntt Chap.2 – 2.10 Surface modification of Biomaterials “Silicone-like” films • Excellent properties for application in many different fields: optical coating (hardness, resistant to scratch, adhesion to polymer lenses, proper refraction index), corrosion protection (chemical inertness), food and pharmaceutical packaging (flexibility, high barrier to O2, H2O vapor and aromas) and others • Prepared by RF plasma deposition of silicone- containing organic monomers in mixture or not with other gases (e.g O2), composition SixCyHkOz is variable and is controlled by changing plasma parameters c om • Used as coating of blood-contacting materials, coating for carbon particles in blood filters and PP hollow fibers membranes in blood oxygenators (reduce production of thrombi and emboli, reduce leakage of blood plasma through the membranes as well as decrease release of particles in the blood stream for coated active carbon) Surface-immobilized biomolecules *Heparin, heparin-like molecules, collagen, albumin and other biological origin confer anti-thrombotic properties on polymer surfaces where they are immobilized polymer need first to be activated, and the to react with the molecule to be coupled with, directly or through a previously attached “spacing arm” molecule ng •They and other biomolecules such as enzymes, antibodies, affinity protein, cell receptor ligands, and drug of all kinds have been chemically or physically immobilized on and within biomaterial supports • Used for a wide rang of therapeutic, diagnostic, separation and bioprocess applications co • These “Hybrid combinations” of natural and synthetic materials confer “biological functionality” of synthetic materials Advanced Program Biomedical Engineering – HUST, Vietnam ng th an du o Chap.2 – 2.10 Surface modification of Biomaterials cu u Immobilized biomolecules and their uses CuuDuongThanCong.com Advanced Program Biomedical Engineering – HUST, Vietnam https://fb.com/tailieudientucntt Chap.2 – 2.10 Surface modification of Biomaterials co ng c om Immobilized biomolecules and their uses (cont) Advanced Program Biomedical Engineering – HUST, Vietnam ng th an du o Chap.2 – 2.10 Surface modification of Biomaterials cu u Immobilized biomolecules and their uses (cont) CuuDuongThanCong.com Advanced Program Biomedical Engineering – HUST, Vietnam https://fb.com/tailieudientucntt 2.10 Surface modification of Biomaterials co ng c om Chap.2 – Advanced Program Biomedical Engineering – HUST, Vietnam ng th an du o Chap.2 – 2.10 Surface modification of Biomaterials cu u Methods for Immobilization of biomolecules - For covalent binding to an inert solid polymer surface, the surfaces must first be chemically modified to provide reactive groups (e.g:-OH,-NH2, -SH, -COOH or -CH=CH2 CuuDuongThanCong.com Advanced Program Biomedical Engineering – HUST, Vietnam https://fb.com/tailieudientucntt Chap.2 – 2.10 Surface modification of Biomaterials co ng c om Methods for Immobilization of biomolecules Advanced Program Biomedical Engineering – HUST, Vietnam ng th an Methods for Immobilization of biomolecules (cont.) 2.10 Surface modification of Biomaterials cu u du o Chap.2 – 14 CuuDuongThanCong.com Advanced Program Biomedical Engineering – HUST, Vietnam https://fb.com/tailieudientucntt 2.10 Surface modification of Biomaterials co ng c om Chap.2 – Advanced Program Biomedical Engineering – HUST, Vietnam ng th an 15 2.10 Surface modification of Biomaterials cu u du o Chap.2 – 16 CuuDuongThanCong.com Advanced Program Biomedical Engineering – HUST, Vietnam https://fb.com/tailieudientucntt 2.10 Surface modification of Biomaterials co ng c om Chap.2 Advanced Program Biomedical Engineering – HUST, Vietnam cu u du o ng th an 17 CuuDuongThanCong.com https://fb.com/tailieudientucntt ... synthetic materials confer “biological functionality” of synthetic materials Advanced Program Biomedical Engineering – HUST, Vietnam ng th an du o Chap .2 – 2. 10 Surface modification of Biomaterials... Immobilized biomolecules and their uses (cont) Advanced Program Biomedical Engineering – HUST, Vietnam ng th an du o Chap .2 – 2. 10 Surface modification of Biomaterials cu u Immobilized biomolecules... Chap .2 – 2. 10 Surface modification of Biomaterials cu u Methods for Immobilization of biomolecules - For covalent binding to an inert solid polymer surface, the surfaces must first be chemically