Stimuli-Responsive Polymeric Nanoparticles for Cancer Therapy

Abstract

Anticancer drugs are cytotoxic in nature and hence have severe side effects due to their non-specific action on normal healthy cells. Nanoparticles have been widely studied to minimize these side effects by selective targeting of cancer cells either by passive or active targeting mechanism. Side effects can be further minimized by delivering drugs to the cancer site without leaking it in the blood during nanoparticle circulation. To achieve this, drug delivery systems need to provide secure encapsulation of the drugs without leakage before reaching the site of action and selectively release encapsulated drugs in the cancer tissues. Recent advances and progress in nanotechnology have resulted in development of stimuli-responsive polymeric materials which have demonstrated great potential in cancer therapy. Stimuli-responsive materials significantly change their physical or chemical properties in response to variations in the environment. Stimuli responsiveness allows secure drug encapsulation in absence of stimuli, but allows rapid drug release in presence of the given stimuli. These stimuli can be inherent and intrinsic to the tumor tissue such as acidic condition, higher tissue temperature, higher redox environment or activity of certain enzymes, or they can be externally applied stimuli such as magnetic field, temperature, ultrasonic waves, or other irradiation. In this chapter, recent advances and applications of various stimuli-responsive polymeric nanosystems for cancer therapy are reviewed.