Modification of Alginates to Modulate Their Physic-Chemical Properties and Obtain Biomaterials with Different Functional Properties.

Modified alginates have a wide range of applications, including in the manufacture of dressings and scaffolds used for regenerative medicine, in systems for selective drug delivery, and as hydrogel materials. This literature review discusses the methods used to modify alginates and obtain materials with new or improved functional properties. It discusses the diverse biological and functional activity of alginates. It presents methods of modification that utilize both natural and synthetic peptides, and describes their influence on the biological properties of the alginates. The success of functionalization depends on the reaction conditions being sufficient to guarantee the desired transformations and provide modified alginates with new desirable properties, but mild enough to prevent degradation of the alginates. This review is a literature description of efficient methods of alginate functionalization using biologically active ligands. Particular attention was paid to methods of alginate functionalization with peptides, because the combination of the properties of alginates and peptides leads to the obtaining of conjugates with properties resulting from both components as well as a completely new, different functionality.

Clinical Outcomes of Mid-Urethral Sling (MUS) Procedures for the Treatment of Female Urinary Incontinence: A Multicenter Study.

Introduction: Stress urinary incontinence (SUI) has a significant impact on the quality of life of many women. Due to embarrassment, most women do not seek medical attention for this condition. The treatment of this problem includes preventive therapies, and in the more advanced stage of urinary incontinence, surgery is a solution. Despite doubts regarding the implantation of urological tapes, the use of tension-free minimally invasive methods constitutes the "gold standard" in the treatment of stress urinary incontinence in women. Objective: The purpose of this article was to evaluate the efficacy and safety of ultralight, polypropylene urogynecological tape (Dallop® NM ULTRALIGHT, Tricomed S.A., Poland) in the surgical treatment of female stress urinary incontinence and mixed urinary incontinence. Methods: This is a multicenter, retrospective cohort study. The included women were adults with stress urinary incontinence (Grade 2 with a positive cough test or Grade 3) or had mixed urinary incontinence and who had undergone "retropubic" or "transobturator" surgery and completed a postoperative follow-up. Results: The study included 68 women from three hospitals. All women completed <6-month and >6-month follow-ups. The median age was 55 (range 36−80). The average value of BMI in the "retropubic" group was 28.6 ± 5.58, and in the "transobturator" group, it was 26.1 ± 4.60. Sixty-three percent (63%, n = 43) of patients were operated on using the "transobturator" method, while thirty-seven percent (37%, n = 25) were operated on using the "retropubic" method. Both the "retropubic" and "transobturator" groups had comparable results in the treatment of SUI. The study showed efficiencies of 84% for the "transobturator" method and 80% for the "retropubic" method. In the "retropubic" group, intraoperative complications were reported in three patients (7%), in comparison to none in the "transobturator" group. There were no tape-related adverse events or infections reported in any case. Conclusions: The presented research confirms the safety and efficacy of retropubic and transobturator tape methods in both short- and long-term follow-up­the success rate was over 80%. In addition to the surgical method used, the experience of the surgeons also has an impact on the final outcome of the surgery. The conducted multi-center study offers the opportunity to eliminate the influence of the human factor on the effectiveness of the procedure.

Influence of Porous Dressings Based on Butyric-Acetic Chitin Co-Polymer on Biological Processes In Vitro and In Vivo.

In spite of intensively conducted research allowing for the development of more and more advanced wound dressing materials, there is still a need for dressings that stimulate not only reparative and regenerative processes, but also have a positive effect on infected and/or difficult-to-heal wounds. Porous dressing materials based on butyric-acetic chitin co-polyester containing 90% of butyryl and 10% of acetyl groups (BAC 90/10) can also be included in the group mentioned above. Two types of dressings were obtained by the salt leaching method, i.e. a porous sponge Medisorb R and Medisorb Ag with an antibacterial additive. The aim of the study was to evaluate biological effects of porous Medisorb R and Medisorb Ag dressings under in vitro and in vivo conditions. In an in vitro biodegradation test, no mass loss of Medisorb R dressing was observed within 14 days of incubation in physiological fluids at 37 °C. However, on the basis of the FTIR (Fourier Transform Infrared Spectroscopy) tests, surface degradation of Medisorb R dressing was observed. Additionally, the antibacterial activity of the porous Medisorb Ag dressing containing microsilver as an antibacterial additive was confirmed. The in vivo studies included inflammatory activity, skin irritation and sensitisation tests, as well an assessment of local effect after contact with subcutaneous tissue up to 6 months and skin wounds up to 21 days. In the in vivo tests, the dressings exhibited neither effects of skin irritation nor sensitisation. Under macroscopic examination, in full thickness defects of subcutaneous tissue and skin, the dressings caused wound healing with no inflammation, undergoing the most gradual biodegradation between weeks 4 and 8, and the observed differences were statistically significant. In the histological assessment, a weakened, limited inflammatory process associated with degradation of the material has been observed. The process of skin wound healing under Medisorb R dressing in the early period was accelerated compared to that observed in the control group with a gauze dressing.

Characteristic Features of Wound Dressings Based on Butyric-Acetic Chitin Copolyesters-Results of Clinical Trials.

The article presents the results of clinical trials of wound dressings whose main ingredient is butyric-acetic chitin copolyester (BAC 90:10). It is a chitin derivative soluble in typical organic solvents. During the trial, the dressings were used on wounds resulting from venous insufficiency or diabetes. The trial evaluated the safety of use and efficacy of three forms of the dressing including porous membrane (Medisorb R Membrane), porous membrane with silver (Medisorb R Ag), and powder (Medisorb R Powder). The clinical trial had a multi-centre character. Three medical units were engaged in the study. The trial included 36 patients (12 men and 24 women). The mean age of the participants was 65 years of age (age range: 26-96). The choice of dressings was made on the basis of preliminary evaluation of the wound, clinical signs of infection, or risk of infection. Medisorb R Membrane dressing was used in 23 patients, Medisorb R Ag dressing was used in 15 patients, and Medisorb R powder was used in two patients. During the course of the trial, there were 10 control visits planned. The obtained results prove the safety and efficacy of dressings in question. The efficacy of treatment was evaluated as good. In the majority of patients, the ulceration was decreased both on the surface and in depth. The success of the treatment relied not only on the applied dressing, but also the stage of the basic disease, the accompanying diseases, and the age of the patient.

Preparation Method of Porous Dressing Materials Based on Butyric-Acetic Chitin Co-Polyesters.

A method for obtaining highly porous materials in the form of film, based on the butyric-acetic chitin co-polyesters, containing 90% of butyryl and 10% of acetyl groups, was developed. The highly porous films, with thickness up to 0.11 mm, were obtained by two methods: (a) pouring 5% BAC 90/10 solution in ethanol on the layer of solid salts (porophor agent) which after solidification was eluted with water; (b) application of the suspension of porophor agent in BAC 90/10 solution in the solvent mixture with density similar to bulk porophor agent. In the final stage, the materials were obtained with porosity up to 95⁻99% and tensile strength 5 cN, which can be used as an active layer of medical dressings. The optimised procedure was used in the production of porous medical dressings (Medisorb) on an industrial scale. In the industrial method, NaCl was used as a porophor agent in the solid form and as a 3% solution in polymer. The final materials were characterised by porosity and other functional parameters at the level recommended for medical dressings. Medisorb series materials do not show in vitro cytotoxic activity.