Chapter 9 – Emerging Biophysics Techniques  421

engineered in the absence of an artificial scaffold too, for example, skeletal muscle has been

engineered in vitro using stem cells and just providing the current cellular and extracellular

biochemical triggers; however, an artificial scaffold in general improves the efficiency of

stem cells ultimately differentiating into regenerated tissues. For example, artificial nanofiber

structures that mimic the native extracellular matrix can stimulate the adhesion of a range

of different cell types and thus act as tissue-​engineered scaffolds for several different tissues,

which interface directly with the extracellular matrix, including bone, blood vessels, skin,

muscles (including the heart muscle), the front surface of the eye (known as the cornea), and

nerve tissue. Active research in this area involves the development of several new biohybrid/​

non-​biohybrid materials to use as nanofiber scaffolds. Modification of these nanofibers

involves chemically functionalizing the surface to promote binding of bioactive molecules

such as key enzymes and/​or various important drugs.

In wounds, infections, and burn injuries, skin tissue engineering using biomimetics

approaches can be of substantial patient benefit. Nanofiber scaffolds can be both 2D and

3D. These can stimulate adhesion of injected stem cells and subsequently growth of new

skin tissue. Similarly, nanobiomimetic tissue-​engineered blood vessels can be used to pro­

mote adhesion of stem cells for stimulating growth of new blood vessels, which has been

demonstrated in major blood vessels, such as the main artery of the aorta. This involves more

complex growth of different types of cells than in skin, including both endothelial cells that

form the structure of the wall of the artery as well as smooth muscle cells that perform an

essential role in regulating the artery diameter and hence the blood flow rate. The efficacy of

these nanofiber implants again can be demonstrated using a range of biophysics tools, here,

for example, including Doppler ultrasound to probe the blood flow through the aorta and to

use x-​ray spectroscopy on implant samples obtained from animal model organisms ex vivo.

Nanoscale particles and self-​assembled synthetic biological nanostructures also have poten­

tial applications as scaffolds for biomimetic tissue.

KEY POINT 9.4

There has been much speculative media coverage concerning bionanotechnology and

synthetic biology in general, both positive and negative in terms of potential benefits

and pitfalls. However, behind the hype, significant steady advances are being made in

areas of nanomedicine in particular, which have utilized the developments of modern

biophysics, and may pave the way to significant future health benefits.

9.4.3  DESIGNER DRUGS THROUGH IN SILICO METHODS

Bioinformatics modeling and molecular simulation tools (see Chapter 8) can now be

applied directly to problems of screening candidate new drugs on their desired targets

to enable the so-​called in silico drug design. These simulation methods often combine ab

initio with classical simulation tools to probe the efficacy of molecular docking of such

candidate drugs. Such virtual screening of multiple candidate drugs can provide invalu­

able help in homing in on the most promising of these candidates for subsequent experi­

mental testing.

The results of these experimental assays, many of which involve biophysics techniques

discussed previously in this book, can then be fed back into refined computational modeling,

and the process is iterated. Similarly, however, undesirable interactions between candidate

new drugs and other cellular machinery benefit from in silico modeling approaches, for

example, to simulate toxicity effects through detrimental interactions with biomolecules that

are not the primary targets of the drug.

KEY BIOLOGICAL

APPLICATIONS:

PERSONALIZED

HEALTHCARE

TOOLS

Lab-​on-​a-​chip devices; In

silico drug design.