Rational design of polymeric micelles for targeted therapeutic delivery

Polymeric micellar drug carriers have emerged as effective tools to enhance the solubility and bioavailability of hydrophobic drugs. These micelles possess a nano size structure that facilitates their passive targeting in human tissues through their enhanced permeability and retention (EPR) effect. However, there is a growing need for active targeting strategies that can direct the micelles to specific sites within the body. In this review, we will explore recent advancements in endogenous targeted delivery strategies using micelles as a delivery system for pharmaceutical ingredients. One approach discussed here is the use of physical and chemical conjugates, which involve the binding of targeting moieties to specific tissues through physical or covalent interactions. Another strategy involves the use of responsive moieties that can release drugs upon internal stimuli at the targeted sites. Ligands, including small molecules, natural polymers, and proteins/peptides, which exhibit high affinities to specific receptors present in the target tissues, are also explored as targeting moieties in micellar drug delivery. Lastly, various approaches for improving therapeutic effects are investigated to evade immune clearance and integrate the micelles into the targeted tissues. Various combined targeting approaches along with the limitations of individual strategies for achieving improved targeting efficiency are discussed. In summary, this review highlights various recent strategies for achieving targeted drug delivery using polymeric micellar carriers to improve efficacy and specificity, ultimately enhancing the therapeutic outcomes for patients.