Synthesis and characterization of a novel hydrogel based on carboxymethyl chitosan/sodium alginate with the ability to release simvastatin for chronic wound healing

Since wound dressing has been considered a promising strategy to improve wound healing, recent attention has been focused on the development of modern wound dressings based on synthetic and bioactive polymers. In this study, we prepared a multifunctional wound dressing based on carboxymethyl chitosan (CMC)/sodium alginate (Alg) hydrogel containing a nanostructured lipid carrier (NLC) in which simvastatin (SIM) has been encapsulated. This dressing aimed to act as a barrier against pathogens, eliminate excess exudates, and accelerate wound healing. Among various fabricated composites of dressing, the hydrogel composite with a CMC/sodium Alg ratio of 1:2 had an average pore size of about 98.44 ± 26.9 μm and showed 707 ± 31.9% swelling and a 2116 ± 79.2 g m-2per day water vapor transfer rate (WVTR), demonstrating appropriate properties for absorbing exudates and maintaining wound moisture. The NLC with optimum composition and properties had a spherical shape and uniform particle size distribution (74.46 ± 7.9 nm). The prepared nanocomposite hydrogel displayed excellent antibacterial activity againstEscherichia coliandStaphylococcus aureusas well as high biocompatibility on L929 mouse fibroblast cells. It can release the loaded SIM drug slowly and over a prolonged period of time. The highest drug release occurred (80%) within 14 d. The results showed that this novel nanocomposite could be a promising candidate as a wound dressing for treating various chronic wounds in skin tissues.

A Wound Treatment Strategy for "Super Long-Term Difficult-to-Heal Wounds": A Single-Center Retrospective Study

Chronic wounds are a challenge for clinicians. Treating chronic wounds in elderly patients is difficult due to comorbidities and poor immunity, tissue renewal, and regeneration. This study shared the therapeutic experiences of 40 patients with super long-term difficult-to-heal wounds and to describe the effects of negative pressure wound therapy (NPWT)-assisted debridement and autologous scalp grafting. Elderly patients with chronic wounds for more than 60 years who underwent NPWT-assisted debridement and autologous scalp grafting between 2015 and 2017 were retrospectively analyzed. Forty patients were identified and analyzed. Among all patients, the average wound area was 56 (interquartile range 30-90) cm². The wound infection rate was 82.1%, and that before the first autologous scalp grafting was 51.3%. The average total number of surgeries was 3, and the number of times the NPWT device was replaced was once. A total of 97.4% of patients had one autologous scalp grafting performed. The transplanted scalp survived completely in 97.4% of patients. One hundred percent of patients had no postoperative complications and healed. The average wound healing time was 34.5 ± 10.1 days. This study showed that NPWT-assisted debridement and autologous scalp grafting have the advantages of high survival rate of the skin and decreased wound recurrence and may be a suitable treatment for super long-term difficult-to-heal wounds in elderly patients.