## 3 Results  
### Multifunctional Nanoparticles for Therapy and Imaging  
#### 3.1.1 Nanoparticle Drug Carriers  
Nanoparticles (NPs) play a crucial role in improving the precision and effectiveness of drug delivery systems, and their design is optimized in terms of coating, size, and shape to enhance biodistribution and pharmacokinetics, and to allow controlled drug release [8]. They possess the unique capability to deliver drugs directly to targeted cells or tissues while minimizing side effects, making them ideal for delivering various therapeutic agents to different regions of the body. Nanocarriers encapsulate and deliver therapeutic agents effectively, improving drug solubility, stability, and bioavailability, while also protecting them from premature degradation and clearance. When designing nanoparticle-based drug delivery carriers, it is essential to take into account both drug release and polymer  
Figure 1: Flow diagram of the literature selection process. biodegradation [9]. Several factors influence the rate of drug release, including: diffusion of the drug through the nanoparticle matrix, the drug's solubility, a combination of erosion and diffusion processes, desorption of the surface-bound or adsorbed drug, and erosion or degradation of the nanoparticle matrix [10]. Multifunctional nanoparticles are under active investigation, paving the way for personalized and improved therapies [8]. In an effort to overcome the limitations of current liver cancer therapies, several authors have synthesized a variety of nanostructured materials employed as drug delivery systems. Figure 2 shows a schematic illustration of the different types of nanocarriers used in the treatment of HCC [11]. Solid lipid nanocarriers (SLNc) represent a modern and efficient drug delivery platform, with significant potential in oncological treatments due to their favorable physicochemical properties. They are colloidal carriers with diameters typically ranging between 50 and 100 nm, which are optimal for avoiding rapid renal clearance and uptake by the reticuloendothelial system [12]. SNLc are composed of a lipid matrix that remains solid at both room temperature and physiological temperature (37 \({}^{\circ}\)C), stabilized by surfactants or cosurfactants. This solid-state behavior is due to the use of lipids with melting points well above body temperature. The solid lipid core provides high physical stability, enables efficient encapsulation of hydrophobic drugs, and supports a sustained and controlled drug release profile [13]. SLNc are capable of improving the bioavailability of active substances by prolonging their half-life, controlling their release, and reducing premature elimination from the body. Through these mechanisms, increased drug concentration at the target tissues is achieved, along with a reduction in systemic toxicity. They protect active compounds from unfavorable physiological conditions, can reduce the frequency of administration, and are versatile in terms of administration routes (intravenous, oral, transdermal). However, their use may be limited by certain challenges, such as premature leakage of the active substance during systemic circulation, insufficient colloidal stability in complex biological environments, and undesirable accumulation in healthy tissues [14]. Figure 2: Examples of nanocarriers for targeted drug delivery in liver cancer. Reproduced with permission from [PERSON] et al. [11]. * Dendrimers  
Dendrimers have demonstrated enhanced functionalities compared to other frequently used nanomaterials. They are synthetic macromolecules with well-defined, spherical, three-dimensional hyperbranched structures, enabling them to exhibit great biocompatibility and unique physicochemical properties. Structurally, dendrimers are composed of a multifunctional core and branched dendrons, with internal cavities capable of encapsulating hydrophobic drugs. This structure allows for improved water solubility, enhanced bioavailability, and increased therapeutic efficacy.