Polymer-Based Designer Particles as Drug Carriers: Strategies to Construct and Modify.

Biological barriers present remarkable challenges for therapeutics delivery, requiring an advanced drug delivery system that can navigate through the complex physiological environment. Polymeric particles provide remarkable versatility due to their adaptable physiochemical properties, facilitating new designs that address complex delivery issues. This review focuses on recent advancements in the morphology of polymeric particles that emulate biological barriers to improve drug efficacy. It includes how structural engineering─such as designing rod-shaped particles for improved cellular uptake, red-blood-cell-shaped particles for prolonged circulation, worm-shaped carriers for improved tissue penetration, and multicompartmental systems for providing combination therapies─profoundly alters drug delivery capabilities. These designer particles exhibit enhanced target specificity, controlled release kinetics, and improved therapeutic outcomes relative to traditional spherical carriers. This particular review also emphasizes how a combination of polymer chemistry and fabrication methods facilitates achieving these advanced structures, while highlighting ongoing challenges in scale-up, reproducibility, and clinical translations. Through the analysis of structure-functional property correlations in various biomimetic designs, we have also attempted to provide insight into future advancements in polymeric delivery systems that have the potential to transform treatment strategies for complicated diseases via shape-directed biological interactions for better therapeutic outcomes.