Ferrocene-containing nanoparticles show reversible redox activity that could trigger drug release mediated by reactive oxygen species (ROS). In this study, four ferrocene-containing polymers, comprising ferrocenylmethyl methacrylate (FMMA)–methacrylic acid (MA) random copolymers, i.e., poly(FMMA-r-MA), were synthesized via radical polymerization, resulting in self-assembled ferrocene nanoparticles (FNPs) with outstanding performance in environments in which ROS are present. These spherical FNPs have tunable diameters ranging from 270 nm to 180 nm and surface charges from −20 mV to −50 mV. Importantly, the diameters and surface charges of the FNPs changed dramatically after 2 h of post-treatment using 0.4 M hydrogen peroxide (H₂O₂) as the oxidant, indicating that the FNPs were highly ROS-sensitive. Furthermore, the controlled release of a model drug from the FNPs, reflected in the release profiles, indicates that these novel FNPs could be potentially used as drug carriers for the effective therapy of ROS-related diseases such as cancer and inflammation.

Background: Astaxanthin (ASTA), a carotenoid, is a strong antioxidant. However, its application in functional foods, pharmaceuticals, and cosmetics remains limited due to its low aqueous solubility and stability. Several different encapsulating materials have been used to improve the stability and bioavailability of ASTA; however, the currently investigated nano-carriers for ASTA require additional improvements with regard to their loading capacity and stability. Methods: In this study, we developed lecithin nano-liposol (Lec NS) as a novel carrier of ASTA using a simple emulsion evaporation method. The physicochemical characteristics including hydrodynamic diameter, polydispersity index, surface charge and morphology were analyzed by DLS and TEM. The antioxidant activity of the ASTA-loaded Lec NS (ASTA@Lec NS) was evaluated using a DPPH radical scavenging assay and in vitro antioxidant assay. The study of in vitro wound healing efficacy was carried out to observe the beneficial effect of antioxidant activity of ASTA@Lec NS on cell migration. Results: ASTA@Lec NS showed improved stability and efficacy owing to improved aqueous solubility of ASTA inside Lec NS. Both in situ and in vitro antioxidant activities of ASTA@Lec NS were higher than that of bare ASTA and Lec NS. It also exhibited strong wound healing efficacy by regulation of ROS level in in vitro cell model. Conclusion: This study revealed that the encapsulation of ASTA into Lec NS using a wet phase transfer enhanced its physiological stability and bioavailability for effective scavenging of reactive oxygen species.

Osteoarthritis (OA) is a degenerative joint disorder associated with inflammation, functional disability, and high socioeconomic costs. The development of effective therapies against inflammatory OA has been limited owing to its complex and multifactorial nature. The efficacy of Prussian blue nanozymes coated with Pluronic (PPBzymes), US Food and Drug Administration-approved components, and their mechanisms of action have been described in this study, and PPBzymes have been characterized as a new OA therapeutic. Spherical PPBzymes were developed via nucleation and stabilization of Prussian blue inside Pluronic micelles. A uniformly distributed diameter of approximately 204 nm was obtained, which was maintained after storage in an aqueous solution and biological buffer. This indicates that PPBzymes are stable and could have biomedical applications. In vitro data revealed that PPBzymes promote cartilage generation and reduce cartilage degradation. Moreover, intra-articular injections with PPBzymes into mouse joints revealed their long-term stability and effective uptake into the cartilage matrix. Furthermore, intra-articular PPBzymes injections attenuated cartilage degradation without exhibiting cytotoxicity toward the synovial membrane, lungs, and liver. Notably, based on proteome microarray data, PPBzymes specifically block the JNK phosphorylation, which modulates inflammatory OA pathogenesis. These findings indicate that PPBzymes might represent a biocompatible and effective nanotherapeutic for obstructing JNK phosphorylation.

Liposomes with embedded magnetic nanoparticles (magnetoliposomes; MLs) are promising nano-platforms for various biomedical applications. The magnetic behavior of MLs depends on the size of embedded magnetic nanoparticles (MNPs); in general, larger MNPs are more advantageous (e.g. increased magnetic signals). However, the insertion of large MNPs into liposome bilayers is constrained by the thickness of the membrane (∼3.4 nm); thus, the incorporation of larger magnetic nanoparticles (>3.4 nm) into liposomes is a major challenge. We developed a solvent-guided approach for the simple and efficient insertion of large MNPs (6 nm or 15 nm) into the liposomal bilayer. MLs with 6 nm MNPs were used for the magnetic field-guided separation of cancer cells by targeting to human epidermal receptor 2 and folate receptor. We also evaluated the nuclear delivery of oligonucleotides by MLs with a cationic lipid formula. The MLs are expected to be versatile nano-platforms for biomedical applications (e.g. disease diagnosis, therapeutics and cell tracking).

Hair loss due to medical conditions, such as alopecia, male pattern baldness, and cancer chemotherapy treatment, has been a common problem for many individuals. Cyclosporin A (CsA), a fungal metabolite, has been reported to be a hair growth modulatory agent and is a potential drug for hair regeneration. However, the effect of topical application of CsA is limited by its poor water solubility. Several delivery systems developed to enhance its solubility still showed poor skin penetration. To overcome these limitations, in this study, we have developed a novel chitosan nanocapsule platform using Pluronic F127 and chitosan without any chemical crosslinking or complicated preparation steps for the enhanced water solubility and high transdermal penetration of CsA. The chitosan nanocapsules (ChiNCs) optimized in terms of structural stability by using chitosan with various molecular weights ranging from 3 to 100 kDa enhanced the skin permeation of CsA through human cadaver skin in vitro. Topical administration of the CsA loaded ChiNCs increased the hair follicles by c.a. 7 times higher than that of the control group, and effectively induced hair growth in C57BL/6 mice in vivo. These results suggest that ChiNCs could be used as a platform for effective transdermal delivery of various hydrophobic drugs.