The increasing knowledge on skin physiology, formulation science and nanotechnology has led to continuous improvements in cosmetics, and introduction of dermocosmetics has been increasing particularly for the management of skin disorders such as acne, eczema, psoriasis, etc. Nowadays, research has been focused on the development of products which can efficiently administer active compounds to the target skin layers while minimizing side effects. The use of multifunctional lipid nanoparticles for cosmetic and dermocosmetic purposes is promising not only because biocompatible ingredients are used in their composition, but also because of their ability to show enhanced skin penetration. Although the introduction of liposomes has been a hallmark of lipid nanoparticles, development of novel systems capable of encapsulating active compounds with tunable release profiles, that show good stability, are easy to manufacture and handle remains a necessity. Solid lipid nanoparticles (SLN) were introduced as alternative formulations for emulsions, liposomes and polymeric nanoparticles, whereas nanostructured lipid carriers (NLC) were developed later as second-generation nanoparticles. However, both SLN and NLC show many inherited advantageous properties to be used for dermal applications including ability to provide occlusion and photoprotective effect and skin hydration, and various SLN and NLC based products are already in the market. This review provides an overview on the current state-of-art of SLN and NLC particularly for cosmetic and dermocosmetic purposes, discuss their formulation composition, structures and preparation techniques. Their use for the topical delivery of active compounds in different skin disorders is highlighted along with examples of commercialized products.

Nucleic acids can modulate gene expression specifically. They are increasingly being utilized and show huge potential for the prevention or treatment of various diseases. However, the clinical translation of nucleic acids faces many challenges due to their rapid clearance after administration, low stability in physiological fluids and limited cellular uptake, which is associated with an inability to reach the intracellular target site and poor efficacy. For many years, tremendous efforts have been made to design appropriate delivery systems that enable the safe and effective delivery of nucleic acids at the target site to achieve high therapeutic outcomes. Among the different delivery platforms investigated, polymeric micelles have emerged as suitable delivery vehicles due to the versatility of their structures and the possibility to tailor their composition for overcoming extracellular and intracellular barriers, thus enhancing therapeutic efficacy. Many strategies, such as the addition of stimuli-sensitive groups or specific ligands, can be used to facilitate the delivery of various nucleic acids and improve targeting and accumulation at the site of action while protecting nucleic acids from degradation and promoting their cellular uptake. Furthermore, polymeric micelles can be used to deliver both chemotherapeutic drugs and nucleic acid therapeutics simultaneously to achieve synergistic combination treatment. This review focuses on the design approaches and current developments in polymeric micelles for the delivery of nucleic acids. The different preparation methods and characteristic features of polymeric micelles are covered. The current state of the art of polymeric micelles as carriers for nucleic acids is discussed while highlighting the delivery challenges of nucleic acids and how to overcome them and how to improve the safety and efficacy of nucleic acids after local or systemic administration.

Use of highly purified antigens to improve vaccine safety has led to reduced immunogenicity and efficacy, resulting in the need for adjuvants to increase and/or modulate the immunogenicity of the vaccine. Despite the need for potent and safe vaccine adjuvants, currently, there are still very few adjuvants in licensed human vaccines. Advances in immunology and molecular biology, especially in the last decade, have allowed researchers to understand better how the adjuvants work and enhance immune responses. While aluminum salts are still the most widely used adjuvants, research has shifted toward the rational design of adjuvant systems containing immunostimulatory molecules. Application of systems biology, which is based on high-throughput technologies using mathematical and computational modeling, has provided a deeper understanding of the biological events elicited by vaccination as well as the influence of other factors such as sex, age, microbiota, genetics and metabolism on the immune response. By this means, it became possible to tailor potential vaccine adjuvants more precisely for a successful vaccine with enhanced efficacy, safety and protection. In this review, after describing the mechanism of action of the adjuvants, current adjuvants in licensed vaccines, as well as those under clinical development will be mentioned in detail. Finally, new approaches in vaccine adjuvant development using systems biology and artificial intelligence will be reviewed, and future directions in vaccine research in regard to efficacy, safety and quality aspects will be discussed.

Chitosan is the most commonly investigated functional cationic biopolymer in a wide range of medical applications due to its promising properties such as biocompatibility, biodegradability, and bioadhesivity, as well as its numerous bioactive properties. Within the last three decades, chitosan and its derivatives have been investigated as biomaterials for drug and vaccine delivery systems, besides for their bioactive properties. Due to the functional groups in its structure, it is possible to tailor the delivery systems with desired properties. There has been a great interest in the application of chitosan-based systems also for the prevention and treatment of infectious diseases, specifically due to their antimicrobial, antiviral, and immunostimulatory effects. In this review, recent applications of chitosan in the prevention and treatment of infectious diseases are reviewed, and possibilities and limitations with regards to technical and regulatory aspects are discussed. Finally, the future perspectives on utilization of chitosan as a biomaterial are discussed.