Homogeneously Synthesized Hydroxybutyl Chitosans in Alkali/Urea Aqueous Solutions as Potential Wound Dressings

Abstract

Wound healing is a clinical challenge, and nontoxic, nonadherent wound dressings that promote healing are urgently needed. Herein, hydroxybutyl chitosans (HBCSs) with the degree of substitution (DS) from 0.41 to 1.38 were synthesized in alkali/urea aqueous solutions, from which sponge-like dressings were prepared by freeze-drying. The pore size of the sponges was in the range of 14.8–18.4 μm, and the porosity was about 98–99%. The compressive strength of the sponges decreased with increasing DS of HBCS. Cytocompatibility studies with normal human dermal fibroblast (NHDF) cells demonstrated that HBCSs were nontoxic and could even promote the growth of fibroblasts. Further tests revealed that HBCS-3 (DS = 0.85) and HBCS-5 (DS = 1.38) exhibited better hemocompatibility and a low blood-clotting index (BCI). Therefore, these two samples were selected as model dressings for in vivo wound-healing assessment in rats. The experiments suggested that HBCS-3 significantly shortened the wound recovery period compared with HBCS-5, chitosan, and gauze by facilitating epithelialization, collagen deposition, and neovascularization and activating the immune system. The results highlighted the potential of HBCSs as efficient dressings for promoting wound healing.

Template-Assisted Magnetron Sputtering of Cotton Nonwovens for Wound Healing Application

“…The skin is considered as the largest organ of the human body, which acts as an effective barrier for the body. − Once the skin suffers serious damage, the wound will severely affect people’s health and life. Also, wound infection is one of the primary complications of today’s wound care management able to impede the healing process and can keep the wound from complete closure. − Hence, wound dressings with antimicrobial activity play an important role in the management of skin wounds since they provide extra protection from infections that are often health threatening.…”

Effect of the Degree of Acetylation of Chitin Nonwoven Fabrics for Promoting Wound Healing

“…During the wound closure process, neovascularization (NV) of the newly regenerated tissue is necessary for the delivery of oxygen and diverse nutrients to the cells present at wound sites. , Therefore, CD31 and α-SMA were selected to determine the newly formed blood vessels. After immunohistochemical staining, it was easy to identify the lumen-like structure of newly formed vessels from the regenerated tissue present at the wound sites (Figure a).…”

Hydroxybutyl Chitosan Centered Biocomposites for Potential Curative Applications: A Critical Review

“…The obtained homogeneous HBC exhibited uniform distribution of substituents, favorable solubility, and unique thermoresponsive phase transformation from the dissolved state to micellar. 29,30 Thus, homogeneous KOH/LiOH/urea and KOH/urea aqueous solution could serve as stable, mild, environmentally friendly, and energysaving reaction media for HBC synthesis. Scheme of homogeneous and heterogeneous modification of CS in alkaline solution is proposed in Figure 1.…”

“…The water solubility of HBC in neutral circumstances is enhanced with the increasing DS of hydroxybutyl groups. 30 The concentration of HBC dissolved in distilled water at 4 °C can be 10 mg/mL 31 or even more than 50 mg/mL. 20 HBC aqueous solution can be maintained indefinitely in its solvated state as long as the temperature is below its LCST.…”