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Abstract 3D‐printed scaffolds can better mimic the function of human skin, both biologically and mechanically. Within the scope of this study, the effect of the addition of different amounts (10, 15, 20 mg) of gentamicin sulfate (GS) to a 10 mL solution of natural and synthetic polymers is investigated. Sodium alginate (SA), gelatin‐methacryloyl (GelMA), and polyvinyl alcohol (PVA) are chosen as bioactive materials. The surface morphology and pore structures are visualized by scanning electron microscopy (SEM). According to the results, it is observed that the pore sizes of all scaffolds are smaller than 270 µm, the lowest value (130 µm) is obtained in the scaffold loaded with 15 mg GS, and it also has the highest tensile strength value (12.5 ± 7.6 MPa). Similarly, it is observed that the tensile strength (9.7 ± 4.5 MPa) is high in scaffold loaded with 20 mg GS. The biocompatibility test is performed with fibroblast cells, and the results show that the scaffolds are biocompatible with cells. The antibacterial test is carried out against the S.aureous and E. coli and the results indicate that all GS‐loaded scaffolds demonstrate antibacterial activity.

Infections caused by antibiotic-resistant pathogens pose a major threat worldwide. There is an urgent need to develop effective strategies to solve this problem. The antibacterial activity of adult mesenchymal stem cells (MSCs) has recently been determined against various bacterial isolates. New approaches, such as Toll-like receptor activation, were used to enhance their antibacterial potency. This study examines the antibacterial activity of TLR agonist (TLR2/TLR1 and/or TLR2/TLR6) activated adipose-derived canine MSCs (AD-MSCs) on multidrug resistant isolates including Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, and Pseudomonas aeruginosa regarding bacterial growth, and minimum inhibitory concentration (MIC) determination. Effects on bacterial morphology were assessed by electron microscopy. Our results showed that the AD-MSCs conditioned medium primed with different TLR agonists inhibited the growth of E. coli and S. aureus, but it had a decreased effect on E. faecalis and P. aeruginosa. Despite this, AD-MSCs conditioned medium prepared with the combination of TLR agonists exhibited antibacterial activity against all isolates. These findings were in parallel with MIC levels of conditioned media. We conclude that adipose-derived canine MSCs primed with TLR agonists (TLR2/TLR1 and TLR2/TLR6 combination) possess antimicrobial activity against multi-drug resistant isolates of E. coli, S. aureus, E. faecalis and P. aeruginosa. Further studies for testing in in vivo models are being planned to assess the potential application of AD-MSCs as an adjunct treatment modality for multi drug resistant infections.

maç: Bu çalışmda melatonin ön-tedavisinin, sıçanlarda mide ülserine bağlı gerçekleşen mikrobiyota değişimine ve oksidatif hasara karşı koruyucu etkilerini araştırmak hedeflenmiştir. Gereç ve Yöntem: Wistar albino sıçanlara (n=32) 12 gün boyunca içme suyu, melatonin (4mg/kg/gün), antibiyotik karışımı (AB; 1 g/L ampisilin + 1 g/L neomisin+ 1 g/L metronidazol), melatonin+ AB içme suyunda verildi. Ardından ülser oluşturuldu. Katkısız içme suyu alan sıçanların yarısına cerrahi işlem yapıldı ama asetik asit uygulanmadı (kontrol grubu; n=8). Cerrahi sonrasındaki 3 gün boyunca uygulanan tüm tedavilere devam edildi. Mide dokuları biyokimyasal ve histopatolojik incelemeler için çıkarıldı. Rektumdan alınan fekal örnekler bakteriyolojik ölçümler için uygun koşullarda saklandı. Bulgular: Tedavi almayan ülser grubunun mide dokusunda MDA, MPO, 8-OHdG, luminol ve lusigenin kemilüminesans seviyeleri, TNF-α ve IL-8 protein ekspresyonları kontrol grubuna göre anlamlı derecede artarken, antioksidan GSH seviyesinin azaldığı gözlendi. Melatonin+AB ön-tedavi uygulaması antioksidan GSH seviyesini ve anti-inflamatuvar IL-10 miktarını artırmış, kaspaz-3 aktivitesini baskılamış ve dokuya nötrofil göçünü kontrol düzeyine inecek şekilde azaltmıştır. Sonuç: Etkin bir antioksidan ve radikal süpürücü olan melatoninin antibiyotik ile birlikte verilmesinin, ülser iyileşmesini hızlandırmada ve kolondaki dağılımı bozulan bakteriyel çeşitliliği düzeltmede daha etkili olacağı öngörülmektedir.

In this study, a dental membrane scaffold was fabricated using a 3D printing technique, and the antimicrobial effect of pomegranate seed and peel extract were investigated. For the production of the dental membrane scaffold, a combination of polyvinyl alcohol, starch, and pomegranate seed and peel extracts was used. The aim of the scaffold was to cover the damaged area and aid in the healing process. This can be achieved due to the high antimicrobial and antioxidant content of pomegranate seed and peel extracts (PPE: PSE). Moreover, the addition of starch and PPE: PSE improved the biocompatibility of the scaffold, and their biocompatibility was tested using human gingival fibroblast (HGF) cells. The addition of PPE: PSE into the scaffolds resulted in a significant antimicrobial effect on S. aureus and E. faecalis bacteria. Moreover, different concentrations of starch (1%, 2%, 3% w/v) and pomegranate peel and seed extract (3%, 5%, 7%, 9%, and 11% PE v/v) were analyzed to obtain the ideal dental membrane structure. The optimum starch concentration was chosen as 2% w/v due to it giving the scaffold the highest mechanical tensile strength (23.8607 ± 4.0796 MPa). The pore sizes of each scaffold were studied by SEM analysis, and pore sizes were arranged between 155.86 and 280.96 μm without any plugging problems. Pomegranate seed and peel extracts were obtained by applying the standard extraction method. High-performance liquid chromatography was performed using the diode-array detection (HPLC-DAD) technique to analyze the phenolic content of the pomegranate seed and peel extracts. Two phenolic components of the pomegranate seed and peel extracts were investigated in the following amounts: fumaric acid (17.56 μg analyte/mg extract) and quinic acid (18.79 μg analyte/mg extract) in pomegranate seed extract and fumaric acid (26.95 μg analyte/mg extract) and quinic acid (33.79 μg analyte/mg extract) in pomegranate peel extract.

Skin diseases are commonly treated with antihistamines, antibiotics, laser therapy, topical medications, local vitamins, or steroids. Since conventional treatments for wound healing (skin allografts, amnion, xenografts, etc.) have disadvantages such as antigenicity of the donor tissue, risk of infection, or lack of basement membrane, skin tissue engineering has become a popular new approach. The current study presents the design and fabrication of a new wound-dressing material by the addition of Juglone (5-hydroxy-1,4-naphthoquinone) to a 25% Polycaprolactone (PCL) scaffold. Juglone (J) is a significant allelochemical found in walnut trees and, in this study is used as a bioactive material. The effects of different amounts of J (1.25, 2.5, 5, 7.5, and 10 mg) on the biocompatibility, mechanical, chemical, thermal, morphological, and antimicrobial properties of the 3D-printed 25% PCL scaffolds were investigated. The addition of J increased the pore diameter of the 25% PCL scaffold. The maximum pore size (290.72 ± 14 µm) was observed for the highest amount of J (10 mg). The biocompatibility tests on the scaffolds demonstrated biocompatible behavior from the first day of incubation, the 25% PCL/7.5 J scaffold having the highest viability value (118%) among all of the J-loaded scaffolds. Drug release of J into phosphate buffered saline (PBS) at pH 7.4 showed that J was completely released from all 25% PCL/J scaffolds within 7 days of incubation.

In this study, three-dimensional tissue scaffolds were fabricated using a 3D printing process. Chitosan (CS) was used as a matrix polymer, and Osage orange extract (OGE) with different amounts was added as a bioactive material. The scaffolds were characterized by SEM, FTIR, tensile testing, antibacterial, and biocompatibility tests. The SEM images revealed that scaffolds had homogeneous morphology, and the size of the pores ranged from 160 µm to 270 µm. FTIR spectrum of the extracted Osage Orange confirmed the successful extraction of the Osage Orange. The OGE addition decreased the swelling capacity of the CS scaffold proportionally. Biocompatibility results proved the biostability properties of the scaffolds. According to the results, the antibacterial activity of the scaffolds against the Staphylococcus Aureus (S. aureus) and Enterococcus Faecalis (E. faecalis) should be provided after detailed optimization.

Juglone (5-hydroxy-1,4-naphthoquinone) (J) is a naphthoquinone structured allelochemical that is mostly found in the roots, leaves, nut-hulls, bark, and wood of walnut (Juglans regia). In this study, the biocompatibility, mechanical, thermal, chemical, morphological, and antimicrobial properties of the poly(lactic acid) (PLA) (w/v)/J (10, 20, 30 mg) electrospun scaffolds were investigated. Based on the results of the study, it was shown that juglone addition increased the antimicrobial properties of the scaffolds against the Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), compared to the neat PLA film after 24 h of contact time. According to the tensile test results, the addition of J made the scaffolds more flexible but decreased the mechanical strength. The cytotoxicity properties of the J-added scaffolds demonstrated a toxic behavior on the first day of incubation. However, with an increase in the J ratio, the fibroblast cell metabolic activity increased for all incubation periods.

In this research, polyvinyl-alcohol (PVA)/gelatin (GEL)/propolis (Ps) biocompatible nanofiber patches were fabricated via electrospinning technique. The controlled release of Propolis, surface wettability behaviors, antimicrobial activities against the S. aureus and P. aeruginosa, and biocompatibility properties with the mesenchymal stem cells (MSCs) were investigated in detail. By adding 0.5, 1, and 3 wt.% GEL into the 13 wt.% PVA, the morphological and mechanical results suggested that 13 wt.% PVA/0.5 wt.% GEL patch can be an ideal matrix for 3 and 5 wt.% propolis addition. Morphological results revealed that the diameters of the electrospun nanofiber patches were increased with GEL (from 290 nm to 400 nm) and Ps addition and crosslinking process cause the formation of thicker nanofibers. The tensile strength and elongation at break enhancement were also determined for 13 wt.% PVA/0.5 wt.% GEL/3 wt.% Ps patch. Propolis was released quickly in the first hour and arrived at a plateau. Cell culture and contact angle results confirmed that the 3 wt.% addition of propolis reinforced mesenchymal stem cell proliferation and wettability properties of the patches. The antimicrobial activity demonstrated that propolis loaded patches had antibacterial activity against the S. aureus, but for P. aeruginosa, more studies should be performed.

Objective: To investigate the effects of plant-derived phenolic compounds (i.e. caffeic acid, cinnamic acid, ferulic acid and vanillic acid) on the production of quorum sensing regulated virulence factors such as pyocyanin, biofilm formation and swarming motility of Pseudomonas aeruginosa (P. aeruginosa) isolates. Methods: Fourteen clinical P. aeruginosa isolates obtained from urine samples and P. aeruginosa PA01 strain were included in the study. The antibacterial effects of phenolic compounds were screened by well diffusion assay. Pyocyanin and biofilm activity were measured from culture supernatants and the absorbance values were measured using a spectrophotometer. Swarming plates supplemented with phenolic acids were point inoculated with P. aeruginosa strains and the ability to swarm was determined by measuring the distance of swarming from the central inoculation site. Results: Tested phenolic compounds reduced the production of pyocyanin and biofilm formation without affecting growth compared to untreated cultures. Moreover, these compounds blocked about 50% of biofilm production and swarming motility in P. aeruginosa isolates. Conclusions: We may suggest that if swarming and consecutive biofilm formation could be inhibited by the natural products as shown in our study, the bacteria could not attach to the surfaces and produce chronic infections. Antimicrobials and natural products could be combined and the dosage of antimicrobials could be reduced to overcome antimicrobial resistance and drug side effects.

Although Saccharomyces boulardii is usually a non-pathogenic fungus, in rare occasions it can cause invasive infection in children. We present the case of an 8-year-old patient in pediatric surgical intensive care unit who developed S. cerevisiae fungemia following probiotic treatment containing S. boulardii. Caspofungin was not effective in this case and he was treated with amphotericin B. We want to emphasize that physicians should be careful about probiotic usage in critically ill patients.

In this study, the main aim was to fabricate propolis (Ps)-containing wound dressing patches using 3D printing technology. Different combinations and structures of propolis (Ps)-incorporated sodium alginate (SA) scaffolds were developed. The morphological studies showed that the porosity of developed scaffolds was optimized when 20% (v/v) of Ps was added to the solution. The pore sizes decreased by increasing Ps concentration up to a certain level due to its adhesive properties. The mechanical, swelling-degradation (weight loss) behaviors, and Ps release kinetics were highlighted for the scaffold stability. An antimicrobial assay was employed to test and screen antimicrobial behavior of Ps against Escherichia coli and Staphylococcus aureus strains. The results show that the Ps-added scaffolds have an excellent antibacterial activity because of Ps compounds. An in vitro cytotoxicity test was also applied on the scaffold by using the extract method on the human dermal fibroblasts (HFFF2) cell line. The 3D-printed SA–Ps scaffolds are very useful structures for wound dressing applications.