Nanoengineering Branched Star Polymer‐Based Formulations: Scope, Strategies, and Advances

Abstract

Soft nanoparticles continue to offer a promising platform for the encapsulation and controlled delivery of poorly water‐soluble drugs and help enhance their bioavailability at targeted sites. Linear amphiphilic block copolymers are the most extensively investigated in formulating delivery vehicles. However, more recently, there has been increasing interest in utilizing branched macromolecules for nanomedicine, as these have been shown to lower critical micelle concentrations, form particles of smaller dimensions, facilitate the inclusion of varied compositions and function‐based entities, as well as provide prolonged and sustained release of cargo. In this review, it is aimed to discuss some of the key variables that are studied in tailoring branched architecture‐based assemblies, and their influence on drug loading and delivery. By understanding structure–property relationships in these formulations, one can better design branched star polymers with suitable characteristics for efficient therapeutic interventions. The role played by polymer composition, chain architecture, crosslinking, stereocomplexation, compatibility between polymers and drugs, drug/polymer concentrations, and self‐assembly methods in their performance as nanocarriers is highlighted.

Soft Character of Star-Like Polymer Melts: From Linear-Like Chains to Impenetrable Nanoparticles

“…Without having this detailed information, the star can be classified as penetrable according to the value of the overcrowding parameter, which was also introduced by the recent two-layer theory applied to hairy nanoparticles in a melt. This classification and the verification of the applicability of the two-layer theory contributes significantly to the accurate estimation of the degree of softness in star melts, which is a key parameter in emerging applications of such materials, as, for example, in nanomedicine, separation membranes, and in all-polymer nanocomposites …”

Single Functional Group Platform for Multistimuli Responsivities: Tertiary Amine for CO2/pH/ROS-Triggered Cargo Release in Nanocarriers

“…For example, keeping a composition similar to that of a linear AB copolymer, the molecular weights of the individual B arms are lowered in AB n -type arrangements, leading to reduced chain entanglement. Therefore, core–shell formulations from the aqueous self-assemblies of miktoarm stars possess highly beneficial traits, including small dimensions, low critical micelle concentrations (CMC), denser corona, enhanced stability, high encapsulation efficiencies, and so forth. − In addition, due to the ease of introducing different polymeric arms, many studies have focused on personalizing miktoarm copolymers with desired functions for better outcomes in intended applications. − In the current study, we utilized the branched architecture to design a stimuli-responsive miktoarm polymer with a tertiary amine group that became an intricate part of the micelle hydrophobic core, offering tuned responsiveness to various stimuli (CO 2 , pH, ROS, and ROS + CO 2 ) and resulting in controlled release of Cur.…”

Stimuli‐Responsive Miktoarm Polymer‐Based Formulations for Fisetin Delivery and Regulatory Effects in Hyperactive Human Microglia

“…Core–shell assemblies from asymmetric miktoarm star polymers have higher corona density in comparison to diblock copolymers, lower critical aggregation concentrations (CAC), smaller diameters, and higher drug‐loading capacities. [ 8–11 ] Spherical micelle is a common morphology adopted by amphiphilic branched polymers upon aqueous self‐assembly. [ 12–15 ] There are examples of miktoarm polymer‐based polymersomes (vesicles) in drug delivery, [ 16–21 ] and a detailed analysis of their compositions and comparisons with linear diblock‐copolymer analogs has recently been reviewed.…”