Lyotropic liquid crystalline phases: Drug delivery and biomedical applications.

Liquid crystal (LC)-based nanoformulations may efficiently deliver drugs and therapeutics to targeted biological sites. Lyotropic liquid crystalline phases (LLCPs) have received much interest in recent years due to their unique structural characteristics of both isotropic liquids and crystalline solids. These LLCPs can be utilized as promising drug delivery systems to deliver drugs, proteins, peptides and vaccines because of their improved drug loading, stabilization, and controlled drug release. The effects of molecule shape, microsegregation, and chirality are very important in the formation of liquid crystalline phases (LCPs). Homogenization of self-assembled amphiphilic lipids, water and stabilizers produces LLCPs with different types of mesophases, bicontinuous cubic (cubosomes) and inverse hexagonal (hexosomes). Moreover, many studies have also shown higher bioadhesivity and biocompatibility of LCs due to their structural resemblance to biological membranes, thus making them more efficient for targeted drug delivery. In this review, an outline of the engineering aspects of LLCPs and polymer-based LLCPs is summarized. Moreover, it covers parenteral, oral, transdermal delivery and medical imaging of LC in targeting various tissues and is discussed with a scope to design more efficient next-generation novel nanosystems. In addition, a detailed overview of advanced liquid crystal-based drug delivery for vaccines and biomedical applications is reviewed.

Stem cell membrane-coated abiotic nanomaterials for biomedical applications.

Nanoscale materials have been extensively employed for diagnostic and therapeutic purposes. However, the developed nanosystems still suffer from some limitations, namely the rapid elimination by the immune system, lack of targeting to specific cells, and insufficient biocompatibility. Therefore, novel strategies based upon a biomimetic approach have received attention to improving the pharmacokinetics and safety profile of nanosystems. One promising strategy is the application of a biomimetic coating consisting of cell membranes derived from different cell types onto nanoparticle cores. Stem cells have been investigated to develop targeted nanodevices owing to their excellent intrinsic tissue-specific homing features, protecting them from the immune system to reach the sites of inflammation. This targeting ability is conferred by a surface repertoire of stem cell-associated biomolecules. Such nanoscopical materials offer sustained circulation and boosted drug accumulation at target sites, augmenting therapeutic efficacy and safety. Additionally, the coating of nanoparticles with cell membranes acts as a camouflage mechanism to increase their circulation time. The current review explores the particular features of stem cell membrane coating as multifunctional biomimetic surface functionalization agents to camouflage nanoparticle cores. Biomedical applications of engineered stem cell membrane-coated nanoparticles, challenges in clinical translation, and their future prospects are addressed.

Nanocarrier-based dermopharmaceutical formulations for the topical management of atopic dermatitis.

Atopic dermatitis (AD) is a chronic disease that affects the skin, and that is characterized by highly itchy inflammation, frequent eczematous lesions, and a fluctuating course. The current treatment consists of a multi-stage approach that aims to establish persistent disease control towards the improvement of the quality of life of the patients. Topical therapy is the basis of AD treatment, however, due to the difficulty of crossing the skin barrier, topical application of drugs remains a challenge. In fact, in addition to the low skin bioavailability, and limited accessibility to deeper skin of the drugs - due to difficulty in penetrating the epidermis - implemented drugs in the clinical are associated with serious adverse effects, which are responsible for safety and efficacy limitations, leading to a reduction in patients' compliance. Nanotechnology arises as an emerging approach for the treatment of AD, allowing for controlled release, targeted delivery, improved penetration, and bioavailability of drugs assets, resulting in marked improved therapeutic efficacy and reduction of adverse effects. Although its promising outputs, additional studies are needed to recognize the toxicological characteristics, cost-benefit, and long-term safety of nanocarriers applied to this end. Advanced drug delivery systems, particularly nanoemulsions, liposomes, ethosomes, transfersomes, solid lipid nanoparticles, nanostructured lipid carriers, nanocrystals, polymeric nanoparticles, and polymeric micelles have been used, and are thoroughly addressed in this review as promising nanoformulations towards the topical treatment of AD.

Nano- and microparticle-stabilized Pickering emulsions designed for topical therapeutics and cosmetic applications.

Pickering emulsions are systems composed of two immiscible fluids, which are stabilized by solid organic or inorganic particles. These solid particles include a broad range of particles that can be used to stabilize Pickering emulsions. An improved resistance against coalescence and lower toxicity, against conventional emulsions stabilized by surfactants, make Pickering emulsions suitable candidates for numerous applications, such as catalysis, food, oil recovery, cosmetics, and pharmaceutical industries. In this article, we give an overview of Pickering emulsions focusing on topical applications. First, we reference the parameters that influence the stabilization of Pickering emulsions. Second, we discuss some of the already investigated topical applications of nano- and microparticles used to stabilize Pickering emulsions. Afterwards, we consider some of the most promising stabilizers of Pickering emulsions for topical applications. Ultimately, we carried out a brief analysis of toxicity and advances in future perspectives, highlighting the promising use of these emulsions in cosmetics and dermopharmaceutical formulations.