Particularities of Urinary Tract Infections in Diabetic Patients: A Concise Review.

Diabetes mellitus is a chronic disease that, untreated or poorly controlled, can lead to serious complications, reducing life expectancy and quality. Diabetic patients are more likely to develop infections, including many common infections, but also pathognomonic ones such as emphysematous pyelonephritis, malignant otitis externa, mucormycosis and Fournier's gangrene. Considering the fact that diabetic patients experience more frequently urinary tract infections (UTIs) with a worse prognosis than non-diabetic people, we conducted a review study based on data in the literature, following the particularities of UTIs in this group of patients, the risk factors, the mechanisms involved and the challenges in their management. The findings highlight that UTI in diabetic patients have some particularities, including a more frequent evolution to bacteremia, increased hospitalizations, and elevated rates of recurrence and mortality than non-diabetic patients. The possible risk factors identified seem to be female gender, pregnancy, older age, UTI in the previous six months, poor glycemic control and duration of diabetes. The mechanisms involved are related to glucosuria and bladder dysfunction, factors related to bacterial strains and host response. The bacterial strains involved in UTIs in diabetic patients and their antibiotic susceptibility profile are, with some exceptions, similar to those in non-diabetic people; however, the antimicrobial agents should be carefully chosen and the duration of the treatment should be as those required for a complicated UTI. The data related to the risk of developing UTIs in patients treated with SGLT-2 inhibitors, a new class of oral hypoglycaemic agents with cardiovascular and renal benefits, are controversial; overall, it was evidenced that UTIs occurred at the initiation of the treatment, recurrent infection was uncommon and the majority of UTIs responded to treatment with standard antibiotics. Moreover, interruption or discontinuation of SGLT-2 inhibitor as a result of UTI was rare and SGLT-2 inhibitors did not increase the risk of severe infections such as urosepsis and pyelonephritis.

Simultaneous Determination of Glibenclamide and Silymarin Released from Chitosan Microparticles by HPLC-ESI-MS Technique: Method Development and Validation.

The study aim was to develop and validate a high-performance liquid chromatography-electrospray ionization mass spectrometry (HPLC-ESI-MS) method to simultaneously determine glibenclamide (Gli) and silymarin (Sil) released from chitosan (CS) microparticles in aqueous solutions. The CS microparticles were synthesized using an ionic gelation method, and their morphology, swelling degree, encapsulation efficiency and active substance release were investigated. Gli and Sil were loaded in different concentrations, and their identification and quantification were performed using the HPLC-ESI-MS method, which was further validated. The drugs' characteristic m/z was found in the higher intensity of retention time (Rt) (Gli, 8.909 min; Sil A, 5.41 min; and Sil B, 5.66 min). The method selectivity and precision are very good, and the blank solution proved no interference. The linearity of the answer function is very good for Sil A (R2 = 1), Sil B (R2 = 0.9998) and Gli (R2 = 0.9991). For Gli, we obtained a limit of detection (LOD) = 0.038 mg/mL and limit of quantification (LOQ) = 1.275 mg/mL; for Sil A, a LOD = 0.285 mg/mL and LOQ = 0.95 mg/mL; and for Sil B, a LOD = 0.045 mg/mL and LOQ = 0.15 mg/mL. A high-resolution HPLC-ESI-MS method was developed and validated, which allowed the simultaneous determination of Gli and Sil loaded in CS microparticles, in a concentration range of 0.025-1 mg/mL.

Preparation and Antimicrobial Activity of Chitosan and Its Derivatives: A Concise Review.

Despite the advantages presented by synthetic polymers such as strength and durability, the lack of biodegradability associated with the persistence in the environment for a long time turned the attention of researchers to natural polymers. Being biodegradable, biopolymers proved to be extremely beneficial to the environment. At present, they represent an important class of materials with applications in all economic sectors, but also in medicine. They find applications as absorbers, cosmetics, controlled drug delivery, tissue engineering, etc. Chitosan is one of the natural polymers which raised a strong interest for researchers due to some exceptional properties such as biodegradability, biocompatibility, nontoxicity, non-antigenicity, low-cost and numerous pharmacological properties as antimicrobial, antitumor, antioxidant, antidiabetic, immunoenhancing. In addition to this, the free amino and hydroxyl groups make it susceptible to a series of structural modulations, obtaining some derivatives with different biomedical applications. This review approaches the physico-chemical and pharmacological properties of chitosan and its derivatives, focusing on the antimicrobial potential including mechanism of action, factors that influence the antimicrobial activity and the activity against resistant strains, topics of great interest in the context of the concern raised by the available therapeutic options for infections, especially with resistant strains.

New Hyaluronic Acid/Polyethylene Oxide-Based Electrospun Nanofibers: Design, Characterization and In Vitro Biological Evaluation.

Natural compounds have been used as wound-healing promoters and are also present in today's clinical proceedings. In this research, different natural active components such as propolis, Manuka honey, insulin, L-arginine, and Calendula officinalis infusion were included into hyaluronic acid/poly(ethylene)oxide-based electrospun nanofiber membranes to design innovative wound-dressing biomaterials. Morphology and average fiber diameter were analyzed by scanning electron microscopy. Chemical composition was proved by Fourier transform infrared spectroscopy, which indicated successful incorporation of the active components. The nanofiber membranes with propolis and Calendula officinalis showed best antioxidant activity, cytocompatibility, and antimicrobial properties against pathogen strains Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa and had an average diameter of 217 ± 19 nm with smooth surface aspect. Water vapor transmission rate was in agreement with the range suitable for preventing infections or wound dehydration (~5000 g/m2 24 h). Therefore, the developed hyaluronic acid/poly(ethylene)oxide nanofibers with additional natural components showed favorable features for clinical use as wound dressings.