Smart drug delivery system

Trigger mechanism

Targeting Precision

Control over release

Key benefits

Potential drawbacks

Use cases

Ref.

pH-sensitive Nanoparticles

Responds to pH changes, typically in acidic conditions.

Targets areas with acidic pH, such as tumors or inflamed regions

Controlled by pH variation, mainly in acidic environments

Effective in acidic regions (tumors, inflammation), high drug encapsulation

Limited to pH-sensitive areas, may have circulation stability challenges

Cancer therapy (targeting tumors), gene delivery, treating inflammation

[50, 51]

Temperature-responsive Nanoparticles

Activates upon changes in temperature, like body temperature.

Can be directed to areas with temperature variations

The release is based on temperature fluctuations

Non-invasive, suitable for controlled release under localized heating

Requires external temperature control, such as localized hyperthermia

Rheumatoid arthritis

(localized drug release), Transdermal drug delivery (pain relief and hormone therapy)

[52, 53]

Enzyme-sensitive Nanoparticles

Responds to pH changes, typically in acidic conditions.

Focuses on tissues or organs with a high presence of target enzymes

Release is tightly controlled by the presence and activity of specific enzymes 

Offers precise targeting through enzyme specificity, reducing off-target effects

Enzyme specificity can be variable, and enzyme activity may differ between individuals

Targeted therapies, particularly in cancer, and protein/peptide delivery

[54, 55]

Magnetic-sensitive Nanoparticles

Release triggered by external magnetic fields or induced heat

Targets specific locations where magnetic fields can be applied, like certain tumors

Release can be regulated by applying an external magnetic field, possibly alongside heating

Non-invasive, can be precisely controlled through an external field, offers localized therapy

Requires a magnetic field for targeting, which may be difficult to apply to deeper tissues

Tumor treatment, localized drug delivery, and tissue regeneration therapies

[56, 57]