Introduction

Nanomedicine is the application of nanotechnology to medical science. It involves the use of nanoscale materials and devices to diagnose, monitor, and treat diseases.

Nanomedicine includes several important areas:

• targeted drug delivery
• medical imaging and diagnostics
• tissue engineering
• regenerative medicine
• nanoscale biosensors

Because nanoparticles are extremely small, they can interact directly with biological molecules such as proteins, DNA, and cell membranes.

The nanoscale dimension is critical because it corresponds to the scale of biological structures.

For example:

Structure	Approximate Size
Human hair	80,000–100,000 nm
Red blood cell	7,000 nm
Virus	100 nm
Protein	10 nm
Nanoparticle	1–100 nm

Nanoparticles are therefore small enough to circulate through blood vessels and interact with individual cells.

At the nanoscale, materials exhibit unique properties due to:

• large surface-to-volume ratio
• increased chemical reactivity
• quantum effects
• enhanced optical properties

These properties allow nanoparticles to perform functions that are impossible for larger particles.

Several types of nanoparticles are commonly used in nanomedicine.

Gold Nanoparticles

Gold nanoparticles have special optical properties and are widely used for:

• medical imaging
• cancer detection
• photothermal therapy

They can absorb light and convert it into heat, which can be used to destroy tumor cells.

Carbon Nanotubes

Carbon nanotubes are cylindrical carbon structures with remarkable strength and conductivity.

Applications include:

• drug transport
• biosensors
• tissue engineering

Their hollow structure allows them to carry molecules through biological environments.

Liposomes

Liposomes are spherical vesicles composed of lipid bilayers similar to biological membranes.

They are particularly useful for:

• drug encapsulation
• controlled drug release
• targeted therapy

Liposomes can protect drugs from degradation while transporting them through the bloodstream.