Bioengineering / Biyomühendislik
Permanent URI for this collectionhttps://hdl.handle.net/11147/4529
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Article Citation - WoS: 7Citation - Scopus: 7Neo-Clerodanes From Teucrium Divaricatum Subsp. Divaricatum and Their Biological Activity Assessment(Elsevier, 2023) Aydoğan, Fadime; Ali, Zülfiqar; Zülfiqar, Fazila; Karaalp, Canan; Khan, Ikhlas A.; Bedir, ErdalFifteen neo-clerodane diterpenoids (1–15), including two undescribed glycosides, teudivaricosides A (1) and B (2), together with a known iridoid glycoside (16) and a phenylpropanoid glycoside (17) from the whole plant of Teucrium divaricatum subsp. divaricatum were isolated. Their structures were determined by spectral data analysis including 1D and 2D NMR and HRESIMS. Neo-clerodane diterpenoids were evaluated for their anti-inflammatory, and antimicrobial activities. None of them showed significant antimicrobial activity against various bacterial and fungal strains (up to 20 µg/mL). All tested compounds were inactive up to the highest tested concentration of 50 µM on iNOS inhibitory activity.Article Citation - WoS: 3Citation - Scopus: 3Structural and Functional Analyses of Gh51 Alpha-L of Geobacillus Vulcani Gs90 Reveal Crucial Residues for Catalytic Activity and Thermostability(Wiley, 2022) Sürmeli, Yusuf; Şanlı Mohamed, GülşahAlpha-L-arabinofuranosidase (Abf) is of big interest in various industrial areas. Directed evolution is a powerful strategy to identify significant residues underlying Abf properties. Here, six active variants from GH51 Abf of Geobacillus vulcani GS90 (GvAbf) by directed evolution were overproduced, extracted, and analyzed at biochemical and structural levels. According to the activity and thermostability results, the most-active and the least-active variants were found as GvAbf51 and GvAbf52, respectively. GvAbf63 variant was more active than parent GvAbf by 20% and less active than GvAbf51. Also, the highest thermostability belonged to GvAbf52 with 80% residual activity after 1 h. Comparative sequence and structure analyses revealed that GvAbf51 possessed L307S displacement. Thus, this study suggested that L307 residue may be critical for GvAbf activity. GvAbf63 had H30D, Q90H, and L307S displacements, and H30 was covalently bound to E29 catalytic residue. Thus, H30D may decrease the positive effect of L307S on GvAbf63 activity, preventing E29 action. Besides, GvAbf52 possessed S215N, L307S, H473P, and G476C substitutions and S215 was close to E175 (acid–base residue). S215N may partially disrupt E175 action. Overall effect of all substitutions in GvAbf52 may result in the formation of the C–C bond between C171 and C213 by becoming closer to each other.Article Citation - WoS: 1Citation - Scopus: 1Exploring the Heterogeneity of Ige-Mediated Food Allergy Through Latent Class Analysis(S. Karger AG, 2022) Akarsu, Ayşegül; Öksel Karakuş, Ceyda; Ocak, Melike; Oral, Nihan; Bilgi, Eyüp; Şahiner, Ümit Murat; Soyer, Özge; Şekerel, Bülent EnisIntroduction: Food allergy (FA) is a heterogeneous disease with multiple morbidities and a huge burden for patients and healthcare systems. Variable manifestations, comorbidities (atopic dermatitis [AD], asthma, and/or allergic rhinitis [AR]), severity (anaphylaxis), and outcomes suggest the existence of different endotypes that cluster analyses may reveal. In this study, we aimed to investigate distinct subgroups among patients with FAs using data from 524 children/adolescents. Methods: 524 patients with IgE-mediated FA (353 male [67%]; median age 4.4 years [IQR:3.0-6.8]), 354 (68%) had multiple FA. The history of AD, asthma, AR, and anaphylaxis was recorded in 59.4%, 35.5%, 24.2%, and 51.2% of the patients, respectively. Latent class analysis was carried out to distinguish clinical FA phenotypes using five potential markers of allergy severity (single/multiple FA, never/inactive/current asthma and AD, AR, and anaphylaxis). Results: Three distinct phenotypes were identified: (1) multiple FA with eczema and respiratory multimorbidity (42%), (2) multiple FA with persistent eczema (34%), and (3) single FA with respiratory multimorbidity without eczema (24%). Compared with the single FA cluster, the prevalence of AD was significantly higher in multiple FA groups. Cluster 1 had the highest frequency of AR and allergic asthma, and the lowest rate of total tolerance of FA. Discussion: We put forward the hypothesis of underlying pathogenesis according to the clinical phenotypes. While skin barrier defect may play a dominant role in the pathogenesis in Cluster 2, immune dysregulation may be dominant in Cluster 3. In Cluster 1, the most severe group, a combination of both skin barrier defects and immune dysregulation may be responsible for the clinical features.Article Citation - WoS: 25Citation - Scopus: 30Fabrication of 3d Printed Poly(lactic Acid) Strut and Wet-Electrospun Cellulose Nano Fiber Reinforced Chitosan-Collagen Hydrogel Composite Scaffolds for Meniscus Tissue Engineering(SAGE Publications, 2022) Güneş, Oylum Çolpankan; Kara, Aylin; Baysan, Gizem; Hüsemoğlu, Reşit Buğra; Akokay, Pınar; Ziylan Albayrak, Aylin; Ergür, Bekir Uğur; Havitçioğlu, HasanThe main goal of the study was to produce chitosan-collagen hydrogel composite scaffolds consisting of 3D printed poly(lactic acid) (PLA) strut and nanofibrous cellulose for meniscus cartilage tissue engineering. For this purpose, first PLA strut containing microchannels was incorporated into cellulose nanofibers and then they were embedded into chitosan-collagen matrix to obtain micro- and nano-sized topographical features for better cellular activities as well as mechanical properties. All the hydrogel composite scaffolds produced by using three different concentrations of genipin (0.1, 0.3, and 0.5%) had an interconnected microporous structure with a swelling ratio of about 400% and water content values between 77 and 83% which is similar to native cartilage extracellular matrix. The compressive strength of all the hydrogel composite scaffolds was found to be similar (∼32 kPa) and suitable for cartilage tissue engineering applications. Besides, the hydrogel composite scaffold comprising 0.3% (w/v) genipin had the highest tan δ value (0.044) at a frequency of 1 Hz which is around the walking frequency of a person. According to the in vitro analysis, this hydrogel composite scaffold did not show any cytotoxic effect on the rabbit mesenchymal stem cells and enabled cells to attach, proliferate and also migrate through the inner area of the scaffold. In conclusion, the produced hydrogel composite scaffold holds great promise for meniscus tissue engineering.