Surface modification approaches

Kommireddy, D., Sriram, S., Lvov, Y. and Mill, D. (2006) Layer-by-layer assembled nanopartide thin films — a new surface modification approach for stem cell attachment. Biomaterials, 27, 4296—4303. 

J. Zhu, M. Yudasaka, M. F. Zhang, D. Kasuya, and S. Iijima, Surface modification approach to the patterned assembly of single-walled carbon nanomaterials, Nano Lett. 3(9), 1239-1243 (2003). 

A number of nanotube surface modification approaches have been reported in the recent years. Non-covalent surface modifications aim to physically wrap polymer chains around the nanotubes or adsorb various surfactant molecules on the surface of nanotubes. Thus,... 

In addition, Mylar (and PET in general) is a widely used biocompatible material. For this reason many approaches to the modification and functionalization of the polymer surface by wet chemistry, plasma processes, or UV treatment have been reported in the literature [19-22]. These surface modification approaches demonstrate that it is possible to improve the reactivity of the PET surface in order to generate specific groups on the surface, or to immobilize biomolecules. Therefore, possibilities for (bio)chemosensing on a fully flexible mechanical support can be envisioned and are very interesting for innovative applications such as smart packaging and biotechnology. 

Several major advantages of using surface segregation in comparison with other surface modification approaches include the control of type and density of the functional groups at the surface or the presence of a reservoir of the functional component remaining in the bulk so that damaged surfaces may be repaired simply by annealing the film. 

As discussed in the above sections, biodegradable PU scaffolds have been attractive for tissue regeneration. Various scaffold fabrication techniques and surface modification approaches have been developed to tailor scaffold properties for... 

Finally, the efficacy of bulk- and surface-modification approaches on 3D scaffolds of commonly used biopolymers remains a fruitful area of research. Therefore, the modification approaches discussed in this review should be transformed to CS nanoparticles and 3D microporous scaffolds. The development of CS nanohybrids is another emerging area that relies on nanoparticles of different sizes, shapes, and materials used to tune CS properties. Nanoparticles can be used to improve CS properties. Since CS is an implantable biomaterial, better control over CS shape memory properties is important for the development of minimally invasive surgeries. 

However, the conventional methods of biomolecule immobilization (covalent binding, physical adsorption, cross-linkings, and entrapment in gels or membranes) present some disadvantages, such as low reproducibility and stability of bioselective elements or poorly controlled spatial deposition. In this sense, evaluating the surface modifications of the biomolecule plays an important role in biosensor development. Nonetheless, improvements are required in many areas, for example, prevention of nonspecific binding, sensitivity, or bioactivity. Some of these problems can be addressed by using different chemical surface modification approaches. 

Polyurethanes with P[AB] copolyoxetane soft blocks are effective and potentially processing-compatible surface modifiers for conventional polyurethanes. This surface modification approach is green in the sense that only a minimal amount of surface modifier (2 wt% or less) is leveraged so as to effect a radical change in surface function. In addition, the 4F chaperone is green in avoiding the use of perfluorinated eight carbon moieties that are likely PFOA precursors. 

Surface nanostructuring by grafting functional polymers to a substrate surface is a surface modification approach that provides the enhancement of the chemical functionality and alters the surface topology of native inorganic and organic materials [182]. 

Plasma-induced graft polymerization (PIGP) is an alternative surface modification approach in which plasma is used to activate the surface the monomer... 

It is hypothesized that nonordered protein adsorption on materials begins the cascade leading to the foreign body reaction, since all normal biological events operate on a system based on specific recognition of proteins and polysaccharides [62,63]. To control nonspecific adsorption, several surface modification approaches have been explored stealth materials are designed to decrease nonspecific protein adsorption while others promote adsorption of specific proteins in an effort to direct biological processes [63,64]. 

Figure 10.1 Classification of PDMS surface modification approaches.

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