Targeting anticancer drugs with pluronic aggregates: Recent updates

Pluronics are triblock (PEO a -b-PPO b -b-PEO a ) copolymers, commercially available in a range of amphiphilicity. Usually, pluronics self-assemble in aqueous solution to form core–shell micelles, but their aggregation behavior is remarkably influenced by the molecular characteristics, solution temperature, and presence of additives. Accompanying transitions result into formation of rigid structures, such as liquid crystals and viscoelastic gels. Certain pluronics have been approved by United States Food and Drug Administration (US-FDA) and European Medicines Agency (EMA) for usage as injectable pharmaceutical excipients. While these carriers have been explored in drug delivery since long, advancements in polymer synthesis have now shifted the focus toward pluronic-based targeted and stimulti-responsive nanomedicines. Majority of these attempts lean over chemical modification of the hydrophilic block in order to enable distinctive identification and elimination of cancerous cells. This review presents the physicochemical and design aspects of pluronic micelles relevant from the standpoint of targeted drug delivery to cancer cells. Using up-to-date literature reports, we have discussed how therapeutic outcomes can be amplified by facilitating the translocation of carriers from tumor interstitium to specific cytosolic targets.