Micelles as colloidal suspension have attracted considerable attention due to their potential use for both cancer diagnosis and therapy. These structures have proven their ability to deliver poorly water-soluble anticancer drugs, improve drug stability, and have good penetration and site-specificity, leading to enhance therapeutic efficacy. Micelles are composed of hydrophobic and hydrophilic components assembled into nanosized spherical, ellipsoid, cylindrical, or unilamellar structures. For their simple formation, they are widely studied, either by using opposite polymers attachment consisting of two or more block copolymers, or by using fatty acid molecules that can modify themselves in a rounded shape. Recently, hybrid and responsive stimuli nanomicelles are formed either by integration with metal nanoparticles such as silver, gold, iron oxide nanoparticles inside micelles or by a combination of lipids and polymers into single composite. Herein, through this special issue, an updated overview of micelles development and their application for cancer therapy will be discussed.

Hydrogel-based polymers are represented by those hydrophilic polymers having functional groups in their chain such as amine (NH₂), hydroxyl [-OH], amide (-CONH-, -CONH₂), and carboxyl [COOH]. These hydrophilic groups raise their potential to absorb fluids or aqueous solution more than their weights. This physicochemical mechanism leads to increased hydrogel expansion and occupation of larger volume, the process which shows in swelling behavior. With these unique properties, their use for biomedical application has been potentially raised owing also to their biodegradability and biocompatibility. Chitosan as a natural copolymer, presents a subject for hydrogel structures and function. This review aimed to study the structure as well as the function of chitosan and its hydrogel properties.

Hydrogels are widely used materials which have many medical applications. Their ability to absorb aqueous solutions and biological fluids gives them innovative characterizations resulting in increased compatibility with biological activity. In this sense, they are used extensively for encapsulation of several targets such as biomolecules, viruses, bacteria, and mammalian cells. Indeed, many methods have been published which are used in hydrogel formulation and biomedical encapsulations involving several cross-linkers. This system is still rich with the potential of undiscovered features. The physicochemical properties of polymers, distinguished by their interactions with biological systems into mucoadhesive, gastro-adhesive, and stimuli responsive polymers. Hydrogel systems may be assembled as tablets, patches, gels, ointments, and films. Their potential to be co-formulated as nanoparticles extends the limits of their assembly and application. In this review, mucoadhesive nanoparticles and their importance for biomedical applications are highlighted with a focus on mechanisms of overcoming mucosal resistance.

Apigenin (Ap) is one of the most important natural flavonoids that has potent anticancer activity. This study was designed, for the first time, to load Ap into chitosan to improve its hydrophobicity and then it was coated with albumin-folic acid to increase its stability and bioavailability and to target cancer cells. The newly developed encapsulated Ap (Ap-CH-BSA-FANPs) was characterized and tested in vitro. The zeta potential of −17.0 mV was within the recommended range (−30 mV to +30 mV), indicating that encapsulated apigenin would not quickly settle and would be suspended. The in vitro results proved the great anticancer activity of the encapsulated apigenin on HePG-2 cells compared to pure Ap. The treated HePG-2 cells with Ap-CH-BSA-FANPs demonstrated the induction of apoptosis by increasing p53 gene expression, arresting the cell cycle, increasing caspase-9 levels, and decreasing both the MMP9 gene and Bcl-2 protein expression levels. Moreover, the higher antioxidant activity of the encapsulated apigenin treatment was evident through increasing SOD levels and decreasing the CAT concentration. In conclusion, the Ap-CH-BSA-FANPs were easy to produce with low coast, continued drug release, good loading capacity, high solubility in physiological pH, and were more stable than the formerly Ap-loaded liposomes or PLGA. Moreover, Ap-CH-BSA-FANPs may be a promising chemotherapeutic agent in the treatment of HCC.