Bioactive Glass-Based Coatings and Modified Surfaces: Strategies for the Manufacture, Testing, and Clinical Applications for Regenerative Medicine - Biological and Biomedical Coatings: Processing and Characterization - page 419

TABLE 9.22
Possible Surface Fictionalization Strategies for Bioactive Glass Surfaces

Modiication ExampleTechnique

Morphological modifications The introduction of pores, gratings, columns, dots, pits, and random

surface roughness

Physiochemical modifications Glow discharge, ion implantation

Biological modifications Adsorption, entrapment, and covalent attachment of biomolecules

on glass surfaces

Strategies to Mimic Extracellular Matrix

Strategies currently include the introduction of pores, gratings, columns, dots, pits, and
random surface roughness (morphological modifications); glow discharge and ion implan-
tation (physiochemical modifications); adsorption, entrapment, and covalent attachment of
biomolecules on glass surfaces (biological modifications) (Table 9.22).
Complex, spatiotemporally regulated interactions between cells and their extracellular
matrix (ECM) regulate many crucial cellular processes in our tissues [51-53]. “Biodriven”
developments in biomaterials research have the potential to generate smart synthetic bio-
active glasses that mimic some of the key structural and biochemical characteristics of the
host tissue ECM [52, 53]. It should be noted that the mechanisms required for bone tissue
attachment and regeneration at the implant interface are still not well understood. As a
result, the importance of ECM structure and function remains controversial but should not
be ignored in developing the next generation of bioactive glass coatings (see Table 9.23).
Surface engineering strategies (see Table 9.22) that mimic ECM form include creating
morphologies, physiochemically engineered surfaces, and biological modification strate-
gies. The precise entrapment, absorbtion, and covalent attachment of biomolecules (e.g.,
peptides, proteins, and other functional groups) have been used to mimic the chemical
clues for cellular differentiation and proliferation.
Physiochemical modifications are aimed at changing surface properties such as sur-
face energy, surface charge, and surface composition to precisely control initial protein
absorption, production, and cellular differentiation. Due to limited size of the chapter,
their description has not been included.

Morphological Approach

Morphological modifications are aimed at creating three-dimensional features (nano-
features) in the form of pores, gratings, columns, dots, pits, and random surface rough-
ness (see Table 9.24). These modifications are aimed at mimicking the ECM morphology.
It should be noted that the sole effect of nanofeatures on cellular activity (bioreactivity)
remains unresolved.

TABLE 9.23
Biomaterials Design Requirements to Mimic ECM Structure and Function
BiomaterialsDesignRequirementsMimicECMStructureandFunction

1 Provide chemical clues to control cellular activity

2 Provide mechanical and surface morphological clues to control cellular activity

3 Controlled delivery of soluble factors directly from the material