PMC

CPPs. CPP-conjugated nanoparticles can be employed to increase entry into multiple types of cells, including nonphagocytic cells. Combining CPPs with particles composed of pH-responsive polymers allows efficient entry into cells followed by cargo release in response to acidic conditions of the endosome.

PEG provides stealth. Particles can be PEGylated to cover surface properties and neutralize the net charge to effectively reduce binding by opsonin proteins and eventual clearance by macrophages. This strategy can prolong the circulation time of particles in the body.

Shape effects. A particle's shape can influence the rate of cellular uptake and body distribution. Particles can be designed to have increased distribution (spherical or disk-like), adherence to junction sites (rod-like), improved uptake by cells (softness), or improved penetration into various gaps (deformable particles).

Light-responsive nanoparticles. Emerging delivery systems can be designed to degrade and release their therapeutic cargo upon light activation using UV, visible, or near-infrared light. The goal of this technology is to precisely control the time and location of particle degradation within a person's body and thereby minimize side effects.

Cell-specific targeting using antibody-conjugated particles. Antibodies that bind specifically to receptors or other structures on the cell's outer membrane can be used for chemical targeting and improve therapeutic delivery. EGFR is a common target receptor that is overexpressed in cancer cells and used as a way to deliver therapeutics to those cells.

Types of therapeutic payloads that can be encapsulated into polymeric nanoparticles. Small polymeric delivery systems in the nano and micro range can be used to deliver diverse therapeutics, including small molecules, proteins, nucleic acids, and diagnostic agents. The small size of these delivery vehicles allows them to circulate the body and reach various target regions. Polymeric particles protect the therapeutic payload from degradation, increase clearance, and reduce unwanted side effects.