Polymer-based thermoresponsive hydrogels for controlled drug delivery

ABSTRACT

Introduction

Controlled drug delivery through hydrogels is generally limited by the poor barrier that polymeric network can create to diffusion mechanism. Stimuli responsive polymers can help in this way guaranteeing that delivery can be sustained and finely controlled using an external stimulus.

Area covered

This review provides an overview of recent studies about the use of temperature as an external stimulus able to work as an efficient new route of drug’s administration. Thermoresponsive hydrogels are discussed and compared in terms of physical properties and mechanism of drug release considering their classification in intrinsical (formed by thermosensitive polymers) and non-intrinsical (polymers with thermosensitive moieties) hydrogels.

Expert opinion

Thermoresponsive hydrogels can be developed by using different polymers added or not with micro/nanoparticles of organic or inorganic origin. In both cases, the final system represents an innovative way for the local and sustained drug delivery in a specific site of the body. In particular, it is possible to obtain an on-demand release of drug by applying a local increase of temperature to the system.

KEYWORDS:

• Drug delivery
• thermoresponsive
• hydrogels
• macromolecules
• polymers

Article highlights

• Controlled drug delivery through polymeric hydrogels is generally limited by the poor barrier to diffusion mechanism.

• Stimuli responsive polymers can guarantee sustained and controlled delivery using external stimuli promoting on-off on demand release.

• Temperature can work as efficient external stimulus able to induce structural conformation within polymeric networks and tunable release rates.

• Thermal responsivity can be intrinsically formed so by thermosensitive polymers or non-intrinsically where polymers are added with thermosensitive moieties.

• Despite the very promising results, some issues, like manufacturing, should be solved before reaching clinics.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.