Comparative evaluation of chitosan-based multifunctional wound dressings: a multistage randomised controlled experimental trial

Background. Wounds of various aetiology are among the most frequent traumatic injuries. A prospective route to improve treatment of this nosology is the development of novel or advancement of the already on-stage dressing materials.Objectives. A comparative experimental assay of novel chitosan-based wound dressings in the healing of soft tissue wounds of different genesis using ultrasound to control biodegradation of the developed dosage form.Methods. Soft tissue wounds were modelled in experimental animals, conventional and lineage male rats, 275 (± 25) g body weight, and male rabbits, 2,900 (± 150) g weight, using a proprietary methodology (Patent on invention RU No. 2703709 dated 23 August, 2018).Two wound dressing samples selected as most promising and applicable in large-volume soft tissue aseptic wounds were tested in the final step of experiment. Ultrasound imaging of the model wound area during the sample material biodegradation was used to control the wound process in more detail. At all steps of experiment, animal models were handled in compliance with GOST 33044-2014 “Principles of Good Laboratory Practice”.Histomorphological assays were carried out with common protocols. Variation statistics was used for the data analysis, including the mean (M) and standard mean error (± m) estimation. The level of statistical significance was p < 0.05.Results. The animal assays and comprehensive evaluation of the obtained data revealed a high healing efficacy of chitosan-based wound coatings. The analyses of wound dressing samples have confirmed their predesigned properties: scaffold stability, capillarity, biodegradability and matrix capacities for the carried drug delivery.Additionally, ultrasound was proved effective to estimate dynamics of the coated wound healing and biopolymer biodegradation processes.Conclusion. The developed chitosan-based wound dressings exhibited efficacy in an experimental model of the soft tissues wound process.The use of ultrasound to study dynamics of the wound process and coating biodegradation provided an adequate congruence between the imaging and tissue histomorphology data, as well as the structure and properties of coating material

Application of chitosan-based wound dressings in local treatment of parenchymal organ wounds: a preclinical experimental study

Background. Injuries of various origins with damage to parenchymal organs remain one of the urgent issues of emergency surgery, despite all the achievements of medical science of the first quarter of the XXI century. One way to improve the quality of treatment for patients with this pathology consists in developing new wound dressings or modifying the properties of existing ones. Hemostatic efficacy is claimed to be one of the main requirements for such dressings.Objective. To perform a comparative analysis of the efficacy of the developed biodegradable wound dressings based on chitosan in the treatment of experimental wounds of parenchymal organs.Methods. The study involved laboratory animals (male rabbits weighing 2900 ± 150 g) to form experimental wounds of parenchymatous organs. The methodology involved wounding the liver via internal method, with the creation of a tissue defect of a given volume, or forming a linear incised wound with fixed parameters followed by application of a developed wound dressing. In the control group of animals, a collagen hemostatic sponge was used as a wound dressing. The animals used in the experiment were kept in accordance with GOST 33044-2014 “Principles of good laboratory practice”. The experiment involved studying the properties of two samples of wound dressings developed on the basis of modified Chitosan Soft (Ch-S) and Chitosan Hard (Ch-H) chitosan, having different properties due to their different structural parameters. The applied ultrasound control of the experimental wound area, with visualization of the samples of the investigated material in the process of biodegradation, enabled the features of the wound process to be studied in more detail. Statistical processing of the study results was carried out by methods of variational statistics, including the calculation of mean values (M), standard errors of mean values (± m). The criterion of the level of statistical significance considered a value of p <0.05. Histomorphological examination of samples was carried out using classical methods.Results. An experimental study conducted on laboratory animals in the treatment of liver wounds, followed by a comprehensive assessment of the results obtained, revealed high efficacy in the developed wound dressings in comparison with the control. The following parameters predicted in the development of wound dressing samples were confirmed: stable hemostatic and scaffold functions, biodegradability, adhesiveness and stimulating effect on bioreparative processes in the wound area. In addition, the ultrasound control algorithm in vivo was adapted in animals to assess the dynamics of the wound process and biodegradation of the studied wound dressings in wounds of parenchymal organs in the experiment, previously used in studying the dynamics of the wound process in soft tissues.Conclusion. The developed samples of chitosan-based wound dressings proved their efficacy in an experimental model of the wound process in parenchymal organs. The applied ultrasonic method for monitoring the biodegradation of the studied wound dressing, as well as the dynamics of the wound process in the liver tissue, revealed the correspondence between the visualized image and the histomorphological picture of the studied tissues, the structure and properties of the wound dressing