## 9 Limitations and Future Perspectives  
The use of nanocarriers for drug delivery may be a promising strategy to effectively treat certain diseases. However, the development of nanocarriers for drug delivery is a complex problem that requires a multidisciplinary approach. Indeed, many factors must be taken into account, such as the size, shape, electrical charge, stability, and biodegradability of nanocarriers, as well as their ability to cross biological barriers such as the blood-brain barrier. Therapeutic polymers can also be used to specifically target certain cells or tissues, depending on their composition and size. Overall, both nanocarriers and therapeutic polymers offer promising platforms for new drug development. However, the choice of platform will depend on the specific characteristics of the disease, underlying biological mechanisms, potential routes of administration, patient compliance, and other factors. The creation of stable and safe drug formulations with improved bioavailability has led to advances in macromolecular precursors, moving from traditional linear block copolymers to amphiphilic compositions with multiple branches through chemical innovation. These polymers have unique structures that are highly useful for drug delivery. For example, their branched architecture minimizes chain entanglement, reducing solution viscosity and facilitating formulation administration. These polymers also offer a strategic balance through their hydrodynamic volume, terminal groups, flexibility, etc., which can improve their bioavailability and circulation in the bloodstream. Multiple branch compositions also exhibit low critical micelle concentrations, high loading capacity, and controlled release of the cargo. Additionally, functional chemical entities can be easily integrated into their architecture, making them very interesting for improved targeting and therapeutic outcome. These attractive characteristics have sparked increasing interest from the scientific community in these macromolecules. The use of multi-arm polymers is becoming increasingly common to tackle various challenges, such as improving formulation stability, therapeutic index, surface functionalization, cellular interactions, and targeted delivery. However, there is still much to be done to establish their effectiveness and performance compared to linear block copolymers. Several variables of polymer-based self-assembly need to be studied, including polymer/drug ratio, compatibility, solvent choice, self-assembly method, and solvent/water ratio during formulation preparation. It is also important to examine the effect of pH and temperature on drug solubilization in star polymer assemblies, as this would establish the stability of micelles at appropriate pH and temperatures. Deepening our understanding of these formulations would be a good approach to improving optimal dosing and patient compliance. Multi-arm-based nanoparticles can help with some of these issues, such as the difficulty in controlling the size and stability of linear copolymer nanoparticles and the need for more in vitro and in vivo research because of their ability to target the site of action, such as a tumor environment or infected cells. Another issue is the recognition of these nanoparticles by the immune system, which will lead to their elimination from the body that will significantly affect the drug release and transportation. The modification of the copolymer surface occurs in order to avoid their recognition as a non-self-composite, which will highly affect their drug delivery efficiency. Hence, these copolymers present a revolutionary way that will completely change how we treat illnesses by enhancing treatment efficacy and minimizing negative effects. To get beyond these issues and maximize the utility of copolymer-based drug delivery in clinical settings, more research and development is necessary.