Background Atopic dermatitis (AD) is a chronic inflammatory skin condition that has a significant impact on quality of life. The immune response and allergy symptoms in AD are triggered by the recognition of specific allergens by IgE antibodies. Cross-reactivity can lead to auto-IgE responses, potentially worsening AD symptoms. Our research aimed to enhance our understanding of allergenic sources, including A. fumigatus, and their role in AD. We focused on molecular mimicry between human AQP3 and A. fumigatus aquaporin. Methods In our in-silico analysis, we compared the amino acid sequences of human aquaporin 3 (AQP3) and A. fumigatus aquaporin with 25 aquaporins from various allergenic sources, sourced from the UniProt and NCBI databases. Phylogenetic relationship analysis and homology-based modeling were conducted. We identified conserved antigenic regions located within the 3D structures. Results The global identity levels among the studied aquaporins averaged 32.6%. One antigenic site exhibited a remarkable local region, with a conserved identity of 71.4%. We categorized the aquaporins into five monophyletic clades (A–E), with group B showing the highest identity (95%), including six mammalian aquaporins, including AQP3. When comparing A. fumigatus aquaporins, the highest identity was observed with Malassezia sympodialis at 35%. Both human and A. fumigatus aquaporins have three linear and three discontinuous epitopes. Conclusions We identified potential linear and conformational epitopes of AQP3, indicating a possible molecular mimicry between humans and A. fumigatus aquaporins. This suggests autoreactivity and potential cross-reactivity, although further validation using in vitro and in vivo experiments is required.

Esomeprazole (ESO) is susceptible to degradation under stress conditions, making polymer selection important for stable solid dispersions. This study evaluated ESO compatibility with five polymers: three grades of hydroxypropyl methylcellulose acetate succinate (HPMCAS-LMP, HPMCAS-MMP, and HPMCAS-HMP), hydroxypropyl methylcellulose phthalate (HPMCP-55), and methacrylic acid–ethyl acrylate copolymer (1:1; Eudragit^® L100-55). Esomeprazole, polymers, and binary mixtures were stored at room temperature and subjected to forced thermal degradation at 60 °C for 16 days. Spectral changes were assessed by visual inspection and attenuated total reflectance–Fourier transform infrared (ATR-FTIR) spectroscopy using the fractional change index (FCI), normalized root-mean-square deviation (NRMSD), and relative maximum spectral difference (relative Max Δ). Density functional theory (DFT) calculations examined interaction energies, non-covalent interactions (NCIs), frontier molecular orbitals, and HOMO–LUMO-based reactivity descriptors. Combining quantitative ATR-FTIR analysis under thermal stress with DFT provides complementary experimental and molecular-level insights into ESO–polymer interactions, including an experimental comparison of three HPMCAS grades. The ESO–HPMCAS-MMP mixture showed the smallest spectral deviations. DFT indicated favorable interactions and relatively low chemical reactivity for the modeled ESO–HPMCAS complex. These findings support the preliminary consideration of HPMCAS-MMP for further formulation studies, although additional evidence is needed to establish comparative chemical compatibility and stability.