NANOFIBROUS SCAFFOLDING FOR BONE TISSUE ENGINEERING - Intelligent Scaffolds for Tissue Engineering and Regenerative Medicine - page 275

Table 14.1. Merits and limitations of methods of generating
nanofibrous materials for tissue regeneration.

Tools Merits Limitations

Phase separation Easyprocess

Controllable size and shape Limited composition

Porosity control Low yield

Low yield

<

Self-assembly Smallfiber diameter ( 10 nm) Short fibers

Control of functional groups Limited composition

Electrospinning Easyprocess

Cost effective Di culty in forming 3D

Broad spectrum of materials shape and pore structure

Fiber aligning possible

generate nanofibers for tissue regeneration. Some merits and limi-
tationsof each toolare summarized in Table14.1.

14.2.1 Phase Separation
The phase separation method utilizes the immiscibility of phases
that comprises the material and removal-off part. When a mater-
ial is dissolved in a solvent or co-solvents and undergoes cooling
below the freezing point(s) of the solvent(s) used, phases are sep-
arated due to thermodynamic immiscibility. The separated phases
form networks with various structures, depending on processing
variables. Ma et al. have reported the production of biodegradable
polymers with a nanofibrous structure by using the phase separa-
tion method. 9 A detailed procedure consists of the steps as follows:
(i)polymerdissolution,(ii)gelation,(iii)solventextraction,and(iv)
freezing and freeze drying. They further reported the nanofibrous-
structured surface improved the cell adhesion and expression of
phenotypes that are specific to bone.

14.2.2 Self-Assembly
Generally, self-assembly is the method of constructing larger-scale
materials using smaller molecular building blocks. Hartgerink et
al. introduced the method of creating self-assembled nanofibers
using peptide amphiphiles targeting for bone. 10 Small molecules