Skin diseases associated with inflammation or oxidative stress represent the most common problem in dermatology. The present study demonstrates that fish scale collagen peptides (FSCP) protect against CoCl₂‐induced cytotoxicity and TNF‐α‐induced inflammatory responses in human HaCaT keratinocyte cells. Our study is the first to report that FSCP increase cell viability and ameliorate oxidative injury in HaCaT cells through mechanisms mediated by the downregulation of key proinflammatory cytokines, namely, TNF‐α, IL‐1β, IL‐8, and iNOS. FSCP also prevent cell apoptosis by repressing Bax expression, caspase‐3 activity, and cytochrome c release and by upregulating Bcl‐2 protein levels in CoCl₂‐ or TNF‐α‐stimulated HaCaT cells. In addition, the inhibitory effects of FSCP on cytotoxicity and the induction of proinflammatory cytokine expression were found to be associated with suppression of the ROS, MAPK (p38/MAPK, ERK, and JNK), and NF‐κB signaling pathways. Taken together, our data suggest that FSCP are useful as immunomodulatory agents in inflammatory or immune‐mediated skin diseases. Furthermore, our results provide new insights into the potential therapeutic use of FSCP in the prevention and treatment of various oxidative‐ or inflammatory stress‐related inflammation and injuries.

In the current study, highly porous and biocompatible regenerated bacterial cellulose–gelatin (rBC–G) composite scaffolds were fabricated for tissue engineering applications. The scaffolds were prepared from porogen added composite solution of BC–G using a casting and leaching approach. The structural characterization of the scaffolds was carried out through field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). FE-SEM images showed the presence and interconnectivity of pores, while FT-IR and XPS spectra confirmed the composite chemistry of the scaffolds. The observed high porosity and rapid swelling of the scaffolds ensure their nutrient exchange ability during practical applications. In vitro biological tests showed that animal fibroblast cells (NIH 3T3) adhered to and proliferated well on the rBC–G composite scaffolds. Cell penetration assessed by Confocal microscopy indicated up to 200 μm infiltration after 7 days of incubation, suggesting the suitability of the scaffolds for three-dimensional cell culture. The enhanced expression of metalloproteases (MMPs) showed that prolonged cell incubation can lead to extracellular matrix (ECM) production inside the 3D rBC–G scaffolds. These results demonstrated that our 3D rBC–G composite scaffolds are candidates for future biomedical applications, including tissue regeneration.

Hydrogels are prototypical matrices for 3D cell culture, of which alginate hydrogels are extensively used. However, ionic crosslinking agents, such as Ca²⁺, are required to form alginate hydrogels, but introduce Ca²⁺-associated cytotoxicity and long-term stability issues. Collagen is a promising biomaterial for 3D cell culture scaffolds primarily due to its biocompatibility. In the present study, the authors designed and fabricated a calcium-free, physically crosslinked, efficient, and bioactive hydrogel composed of alginate, marine collagen, and agarose (AmCA) for use in 3D cell cultures. This AmCA hydrogel was assessed by FTIR, swelling property, scanning electron microscopy, phase contrast microscopy, cell proliferation, cell viability, confocal microscopy, transparency and RT-PCR analyses. The gel was found to exhibit excellent cytocompatibility with various tumor and non-tumor cells, to generate high yields of multicellular spheroids, and to promote cellular activity. Furthermore, the transparency of the AmCA hydrogel suggests it can be used without cell-tracking chemicals in morphological studies of cell cultures. Taken together, it would appear that the described physically crosslinked AmCA hydrogel could provide a novel platform for the development of customizable, transparent, biocompatible, functional, easy-to-produce, and cost-effective scaffolds for use in 3D cultures of various cell types.

Single pH-dependent drug delivery systems have been widely used for colon-targeted delivery, but their efficiency is often hampered by the variation in gut pH. To overcome the limitation of single pH-dependent delivery systems, in this study, we developed and evaluated the therapeutic potential of budesonide-loaded dual pH/time-dependent nanoparticles (NPs) for the treatment of colitis. Eudragit FS30D was used as a pH-dependent polymer, and Eudragit RS100 as a time-dependent controlled release polymer. Single pH-dependent NPs (pH_NPs), single time-dependent NPs (Time_NPs), and dual pH/time-dependent NPs (pH/Time_NPs) were prepared using the oil-in-water emulsion method. The physicochemical properties and drug release profiles of these NPs in gastrointestinal (GI) tract conditions were investigated. The therapeutic potential and in vivo distribution of the NPs were evaluated in a dextran sulfate sodium (DSS)-induced colitis mice model. The pH/Time_NPs prevented a burst drug release in acidic pH conditions and showed sustained release at a colonic pH. The in vivo distribution study in the mice GI tract demonstrated that pH/Time_NPs were more efficiently delivered to the inflamed colon than pH_NPs were. Compared to the single pH_NPs-treated group, the pH/Time_NPs-treated group showed increased body weight and colon length and markedly decreased disease activity index, colon weight/length ratios, histological damage, and inflammatory cell infiltration in colon tissue. Our results demonstrate that the dual pH/time-dependent NPs are an effective oral colon-targeted delivery system for colitis therapy.