Due to their unique structural properties bacterial cellulose (BC) hydrogels find possible usage in many fields such as cosmetology, food industry, or medicine. In this study, photoactive BC ...hydrogels are investigated through modifications of their structural, mechanical, and pro‐oxidant properties resulting from graphene quantum dots (GQDs) encapsulation. Detailed structural analysis is conducted by atomic force microscopy, transmission electron microscopy and scanning electron microscopy, X‐ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and X‐ray diffraction method. Dynamic mechanical analysis is performed to study the changes in storage modulus, loss modulus and tan δ. Pro‐oxidative properties of new designed composites are tested by electron paramagnetic resonance (EPR). Structural and mechanical analyses show successful encapsulation of GQDs into BC whereas EPR measurements indicate high potential of these composites for singlet oxygen production.
Photoactive GQDs‐BC composite hydrogels are produced by immersing BC in GQDs acetone solution. Detailed structural, chemical and mechanical analyses show that photoactive GQDs are encapsulated into BC polymer matrix. Porosity test shows significant pore enlargement of GQDs‐BC composite hydrogels. Composite hydrogels are highly potent oxygen radical generator and present advanced material for wound dressing application.
Therapy of bacterial urinary tract infections (UTIs) and catheter associated urinary tract infections (CAUTIs) is still a great challenge because of the resistance of bacteria to nowadays used ...antibiotics and encrustation of catheters. Bacterial cellulose (BC) as a biocompatible material with a high porosity allows incorporation of different materials in its three dimensional network structure. In this work a low molecular weight chitosan (Chi) polymer is incorporated in BC with different concentrations. Different characterization techniques are used to investigate structural and optical properties of these composites. Radical scavenging activity test shows moderate antioxidant activity of these biocompatible composites whereas
in vitro
release test shows that 13.3% of chitosan is released after 72 h. Antibacterial testing of BC-Chi composites conducted on Gram-positive and Gram-negative bacteria causing UTIs and CAUTIs (
Escherichia coli
,
Pseudomonas aeruginosa
,
Klebsiella pneumoniae
) and encrustation (
Proteus mirabilis
) show bactericidal effect. The morphology analysis of bacteria after the application of BC-Chi shows that they are flattened with a rough surface, with a tendency to agglomerate and with decreased length and width. All obtained results show that BC-Chi composites might be considered as potential biomedical agents in treatment of UTIs and CAUTIs and as a urinary catheter coating in encrustation prevention.
Bacterial cellulose-chitosan composite with antibacterial and moderate antioxidant activity for potential UTI/CAUTI treatment and catheter coating in encrustation prevention.
Bacterial infection and their resistance to known antibiotics delays wound healing. In this study, nanochitosan dots (nChiD) produced by gamma irradiation have been encapsulated in bacterial ...cellulose (BC) polymer matrix to study the antibacterial potentials of these nanocomposites and their possible usage in wound healing treatment (scratch assay). Detailed analyses show that nChiDs have disc-like shape and average diameter in the range of 40 to 60 nm depending of the applied dose. All nChiDs as well as BC-nChiD nanocomposites emit green photoluminescence independently on the excitation wavelengths. The new designed nanocomposites do not have a cytotoxic effect; antioxidant analysis shows their moderate radical scavenging activity whereas antibacterial properties show significant growth inhibition of strains mostly found in difficult-to-heal wounds. The obtained results confirm that new designed BC-nChiD nanocomposites might be potential agent in wound healing treatment.
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•New innovative approach for wound healing treatment•Photoactive nanochitosan dots produced by gamma irradiation•Encapsulation of nanochitosan dots in bacterial cellulose•Nanochitosan dots/bacterial cellulose nanocomposite as moderate antioxidant agent•Nanochitosan dots/bacterial cellulose nanocomposite as strong bactericidal agent
Introduction: Drug Reaction with Eosinophilia and Systemic Symptoms Syndrome is a rare and severe form of drug induced delayed-type hypersensitivity reaction with mortality rate up to 10%. It usually ...manifests with skin rash, fever, lymphadenopathy, hematological abnormalities and involvement of one or more internal organs. Establishing the diagnosis is sometimes late due to variable clinical presentation. Current recommendations for therapy rely mainly on expert opinions, retrospective studies, case reports and series. Sulfasalazine was firstly synthesized in 1930 and is currently being prescribed for various inflammatory and rheumatic diseases. Case report: We present a 45-year-old patient who was prescribed sulfasalazine tablets by a rheumatologist due to reactive arthritis. In the fourth week of therapy, he developed skin rash and fever up to 39.5°C. On admission, generalized maculopapular exanthema covering over 60% of the body surface area, edema of the lower eyelids and bilateral cervical and inguinal lymphadenomegaly were registered. Laboratory findings showed leukocytosis with significant eosinophilia, lymphocytosis, elevated bilirubin values, ALT <100 U/L, while ultrasonography of the upper abdomen confirmed hepatosplenomegaly. The patient was diagnosed with Drug Reaction with Eosinophilia and Systemic Symptoms Syndrome using RegiSCAR and J-SCAR diagnostic criteria and systemic therapy with methylprednisolone at a dose of 1.5 mg/kg and other supportive therapy was applied, which resulted in complete regression of the skin changes and normalization of laboratory values. Conclusion: The authors would like to recall the occurrence of Drug Reaction with Eosinophilia and Systemic Symptoms Syndrome as a rare and potentially fatal drug reaction in which awareness of this disease is of key importance for early recognition. Identification of the offending drug followed by a prompt withdrawal and subsequent treatment is essential for decreasing disease related morbidity and mortality and thus we wish to familiarize the sulfasalazine prescribers with this syndrome.
In the two groups of patients with myopic astigmatism the uncorrected near vision was tested after catatract surgery. Each group with 20 patients ages 60-80. All patients enrolled in study have ...uncorrected far vision 0.5 or better on Snellen tables. In the first group patients were with the rule after surgery myopic astigmatism (1-1.50 Diopter), and in the second group were patients with against the rule after surgery myopic astigmatism (1-1.50 Diopter). Patients in the second group with against the rule astigmatism achieved significantly (p<0.01) better uncorrected near vision.
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