Reactive Oxygen Species (ROS)-Assisted Nano-Therapeutics Surface-Decorated with Epidermal Growth Factor Fragments for Enhanced Wound Healing.

In this study, stimuli-responsive liberation of an epidermal growth factor fragment (EGFfr) is accomplished using nanofibrous meshes to improve wound healing effects. Electrospun nanofibers are fragmented by mechanical milling, followed by aminolysis to fabricate powdered nanofibrils (NFs). EGFfrs are covalently immobilized on NFs via thioketal linkers (EGFfr@TK@NF) for reactive oxygen species (ROS)-dependent liberation. EGFfr@TK@NF exhibits ROS-responsive liberation of EGFfr from the matrix at hydrogen peroxide (H2 O2 ) concentrations of 0-250 mm. Released EGFfr is confirmed to enhance the migration of HaCaT cell monolayers, and keratinocytic gene expression levels are significantly enhanced when H2 O2 is added to obtain the released fraction of NFs. An in vivo study on the dorsal wounds of mice reveals that EGFfr-immobilized NFs improve the expression levels of keratin1, 5, and 14 for 2 weeks when H2 O2 is added to the wound sites, suggesting that the wounded skin is re-epithelized with the original epidermis. Thus, EGFfrs-immobilized NFs are anticipated to be potential nanotherapeutics for wound treatment in combination with the conventional disinfection process with H2 O2 .

Liposome-assisted penetration and antiaging effects of collagen in a 3D skin model.

BACKGROUND: Collagen is a major component of the extracellular matrix that supports the epidermal layers of the skin; thus, many strategies have been made to enhance the topical delivery of collagen for antiaging purposes. In addition, our previous study indicated that liposome can help the penetration of active ingredients into the skin. AIMS: To produce stable collagen-encapsulated liposomes to improve the topical delivery of collagen. METHODS: Collagen-encapsulated liposomes were fabricated using high-pressure homogenization method. The colloidal stability and adhesion ability were confirmed using dynamic light scattering, and spectrofluorophotometer, respectively. Keratinocyte differentiations of 3D skin before and after treatment with collagen-encapsulated liposomes were confirmed by real-time PCR. RESULTS: In comparison with native collagen, collagen-encapsulated liposomes enhanced collagen retention in artificial membranes by twofold, even after repeated washings with water. In addition, real-time PCR results indicated that 3D skin treated with collagen-encapsulated liposomes exhibited higher levels of collagen, keratin, and involucrin, even after ethanol treatment. CONCLUSION: Liposomes could serve as efficient delivery vehicles for collagen, thereby enhancing its antiaging effects.

Spectroscopic techniques for monitoring stem cell and organoid proliferation in 3D environments for therapeutic development.

Spectroscopic techniques for monitoring stem cell and organoid proliferation have gained significant attention in therapeutic development. Spectroscopic techniques such as fluorescence, Raman spectroscopy, and infrared spectroscopy offer noninvasive and real-time monitoring of biochemical and biophysical changes that occur during stem cell and organoid proliferation. These techniques provide valuable insight into the underlying mechanisms of action of potential therapeutic agents, allowing for improved drug discovery and screening. This review highlights the importance of spectroscopic monitoring of stem cell and organoid proliferation and its potential impact on therapeutic development. Furthermore, this review discusses recent advances in spectroscopic techniques and their applications in stem cell and organoid research. Overall, this review emphasizes the importance of spectroscopic techniques as valuable tools for studying stem cell and organoid proliferation and their potential to revolutionize therapeutic development in the future.

Reactive oxygen species-responsive clicked assembly of gold nanoparticles to enhance photothermal therapy.

To enhance the efficacy of photothermal therapy (PTT) at tumor sites, we designed a reactive oxygen species (ROS)-responsive gold nanoparticle (AuNP)-based nanosystem in which azide-decorated AuNPs (N3@AuNPs) and diselenide-coated alkyne-decorated AuNPs (Se/Ak@AuNPs) were separately prepared for selective clicking into nanoclusters when exposed to ROS. Se/Ak@AuNPs were dual-functionalized with alkyne moieties and diselenide linkers embedded in a long chain of polyethylene glycol (PEG) to enable the alkyne moieties of Se/Ak@AuNPs to be inaccessible to the azide moieties of N3@AuNPs owing to steric hindrance. At tumor sites where the ROS level is elevated due to the increased metabolic activity, cellular receptor signaling, mitochondrial dysfunction, and oncogene activity, the diselenide linkers were cleaved, leading to the liberation of the long PEG chains tethered to AuNPs, and the alkyne moieties could be recognized by the surrounding azide moieties to generate a click reaction. The clicked AuNPs formed clustered nanoparticles with increased size. Upon 808 nm laser irradiation, these large clusters of AuNPs significantly enhanced the photothermal conversion efficiency compared with that of isolated AuNPs. In vitro studies revealed that the AuNP clusters exhibited a noticeably higher apoptosis rate than AuNPs. Therefore, ROS-responsive clicked AuNP clusters can be a potential tool for PTT enhancement in cancer treatment.

Korean Amberjack Skin-Inspired Hyaluronic Acid Bioink for Reconstruction of Human Skin.

Decellularized extracellular matrix (dECM) has been extensively employed as tissue engineering scaffolds because its components can greatly enhance the migration and proliferation of cultivating cells. In this study, we decellularized Korean amberjack skin and incorporated soluble fractions in hyaluronic acid hydrogels with 3D-printed tissue engineering hydrogels to overcome any limitation of animal-derived dECM. The hydrolyzed fish-dECM was mixed with methacrylated hyaluronic acid and chemically crosslinked to 3D-printed fish-dECM hydrogels, where fish-dECM contents affected both printability and injectability of the hydrogels. Swelling ratios and mass erosion of the 3D-printed hydrogels were dependent on fish-dECM contents, where higher fish-dECM in the hydrogel increased swelling ratios and mass erosion rates. The higher content of fish-dECM considerably enhanced the viability of the incorporated cells in the matrix for 7 days. Artificial human skin was constructed by seeding human dermal fibroblasts and keratinocytes in the 3D-printed hydrogels, and a formation of a bilayered skin was visualized with tissue staining. Thus, we envision that 3D-printed hydrogels containing fish-dECM can be an alternative bioink composed of a non-mammal-derived matrix.