RESUMEN
(1) Background: Wounds with damages to the subcutaneous are difficult to regenerate because of the tissue damages and complications such as bacterial infection. (2) Methods: In this study, we created burn wounds on pigs and investigated the efficacy of three biomaterials: polycaprolactone-gelatin-silver membrane (PCLGelAg) and two commercial burn dressings, Aquacel® Ag and UrgoTulTM silver sulfadiazine. In vitro long-term antibacterial property and in vivo wound healing performance were investigated. Agar diffusion assays were employed to evaluate bacterial inhibition at different time intervals. Minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and time-kill assays were used to compare antibacterial strength among samples. Second-degree burn wounds in the pig model were designed to evaluate the efficiency of all dressings in supporting the wound healing process. (3) Results: The results showed that PCLGelAg membrane was the most effective in killing both Gram-positive and Gram-negative bacteria bacteria with the lowest MBC value. All three dressings (PCLGelAg, Aquacel, and UrgoTul) exhibited bactericidal effect during the first 24 h, supported wound healing as well as prevented infection and inflammation. (4) Conclusions: The results suggest that the PCLGelAg membrane is a practical solution for the treatment of severe burn injury and other infection-related skin complications.
RESUMEN
The purpose of this research is to investigate the effect of different oxidation degrees and volume ratios of components on the physical properties and biocompatibility of an in situ cross-linking chitosan-hyaluronic acid-based hydrogel for skin wound healing applications. Carboxymethyl groups (-CH2COOH) were introduced to the polymer chain of chitosan, producing N,O - Carboxymethyl Chitosan (NOCC). Hyaluronic acid was oxidized to obtain aldehyde hyaluronic acid (AHA) with three oxidation degrees (AHA40, AHA50 and AHA60). The gelation was induced by forming Schiff base linkage between aldehyde groups of AHA and amino groups of NOCC. Then, the polysaccharide derivatives were combined at three NOCC:AHA volume ratios (3:7, 5:5 and 7:3) to form composite hydrogels without using any additional cross-linker. FT-IR analysis, surface morphology observation and wettability test, in vitro degradation test and rheological analysis were carried out to characterize the hydrogels. Additionally, in vitro cytotoxicity and in vivo wound healing evaluations were also conducted to study the biocompatibility of the composite. Our findings showed that when increasing the volume of NOCC, the homogeneity and hydrophobicity of the resulting hydrogels were also improved and their pore walls became thicker, leading to slower degradation rate. On the other hand, when raising the oxidation degree of AHA, the hydrophilicity of the gels decreased and less time was required to form the gel matrix. Besides, the obtained in vitro and in vivo results indicated that lower oxidation degree of AHA supports cell proliferation, cell attachment and wound healing process better. It is also concluded that NOCC-AHA40 5:5 hydrogel is most suitable for skin wound healing applications since it possesses superior morphology with high uniformity, favorable pore size and suitable density along with appropriate wettability. The NOCC-AHA gel matrix is expected to be used as a delivery system for other factors and employed as an effective bio-glue in further tissue engineering applications.