Self-assembled block polymer aggregates in selective solution: controllable morphology transitions and their applications in drug delivery

ABSTRACT

Introduction

Amphiphilic block copolymers are able to self-assemble into rich morphologies with high controllability for drug delivery. Great efforts have been made for decades to construct efficient drug delivery systems (DDSs) using nanostructured self-assemblies to overcome the drawbacks of pharmaceuticals, such as low aqueous solubility, premature drug release during circulation, and undesirable side effects.

Areas covered

Here we review the researches of self-assembled block polymer aggregates with a focus on the shape-forming and shape-changing mechanisms, and applications of controlling morphology transition by multiple factors in drug delivery. We tend to provide a comprehensive description of the connection between structure-changing thermodynamics, kinetics, and influencing factors, thus to enlighten more pathways for future developments in the field of drug delivery.

Expert opinion

By understanding the underlying mechanisms for the structure formation and transition, it enables versatile applications in DDSs design by altering drug morphologies. However, developing more sophisticated and multifunctional polymeric nanocarriers is still challengeable in the clinical application, which would hold considerable potential in promoting the efficiency in morphology control to achieve higher intelligence of drug delivery.

KEYWORDS:

• Drug delivery
• block copolymers
• self-assembly
• morphology transition

Article highlights

• The self-assembly of block copolymers (BCPs), as a promising ‘bottom-up’ ordered construction, is capable of forming a wide array of morphologies with higher controllability and diverse potential.

• The morphological formation and transition are determined by the force balance between repulsive and attractive interactions, which can be depicted by basic thermodynamics and predicted by packing parameters.

• BCPs can self-assemble into intelligent particles with desired nanostructures by modifying different formulation factors and external stimuli.

• Intelligent drug nanocarriers aggregated by BCPs could acquire enhanced stability and ascendant drug-loading functions.

• Novel stimulus-responsive systems also have great potential and are achieved by releasing drugs during morphology transitions by applying appropriate stimuli such as pH, temperature, light, and so on.

This box summarizes key points contained in the article.

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 work was supported by National Science and Technology Major Project (No. 2017YFA0205400) and the National Science Foundation Grant of China under Grant (No. 81503005); Six Talent Peak Project in Jiangsu Province (No. SWYY-106); the Priority Academic Program Development of Jiangsu Higher Education Institutions.