Bacterial cellulose (BC) is a high-purity nanometer cellulose secreted by some bacteria. Compared with plant cellulose, it possesses an array of unique properties, including high crystallinity, high water content, good biocompatibility, high mechanical strength and an ultra-fine fiber network. BC is prosperous as a new type of biomedical material, which has medical applications such as wound dressing, artificial skin, artificial blood vessels and tissue engineering scaffolds. There are, however, some problems to be solved on the large-scale application of BC, such as the high cost, low yield, and poor mechanical stability and so on.
ObjectiveTo evaluate the effectiveness of liquid wound dressing in the treatment of chronic ulcer wounds. MethodsBetween January 2014 and October 2015, 84 patients with chronic ulcer wounds were included and divided into 2 groups randomly. The chronic ulcer wounds were covered with liquid wound dressing in the treatment group (n=44) and were managed with iodophor in the control group (n=40). There was no significant difference in age, gender, causes, location, wound area, and disease duration between 2 groups (P > 0.05). The frequency of dress changing, effective rate of treatment, wound healing time, wound healing rate at 5, 10, and 20 days, positive rate of bacteria culture at 1, 5, and 10 days, and the rate of side effect were recorded and compared between 2 groups. Vancouver scar scale was used to evaluate scar formation. ResultsThe effective rate of the treatment group (100%) was significantly higher than that of the control group (85%) (P=0.009). The frequency of dress changing in the treatment group[(11.36±3.40) times] was significantly lower than that in the control group[(16.94±4.51) times] (t=-6.231, P=0.000). The wound healing rates at 5, 10, and 20 days were significantly increased (P < 0.05) and the wound healing time was significantly decreased (t=-6.627, P=0.000) in the treatment group when compared with the control group. The positive rates of bacteria culture at 5 and 10 days in the treatment group were significantly lower than those in the control group (χ2=12.313, P=0.000; P=0.005), but no significant difference was found at 1 day (χ2=0.066, P=0.797). Side effect was observed in 4 cases of the control group. Vancouver scar scale score was 8.59±1.32 in the treatment group and was 9.85±1.65 in the control group, showing significant difference (t=-3.752, P=0.000). ConclusionThe application of the liquid wound dressing in the treatment of chronic ulcer wound can improve the wound healing rate, shorten the healing time and decrease the frequency of dress change, which could promote the wound healing process.
5–20 wt% trimethoxysilylpropyl octadecyldimethyl ammonium chloride (QAS) was used to modify Poly (ε-caprolactone) (PCL)-gelatin hybrid to fabricate non-leaching antibacterial nanofiber membranes (PG-Q) by electrospinning. The results from scanning electron microscopy (SEM) and transmission electron microscopy (TEM) indicated that the QAS leaded to phase separation between the QAS and PCL. Hydrophilic test demonstrated that the PG-Q nanofiber membranes had hydrophobic surface, which was help for peeling off the dressing from the wound. Additionally, the physical and chemical cross-linking between the QAS/PCL and QAS/gelatin were confirmed by Fourier transform infrared (FTIR), which were good for long lasting antibacterial effect. The PG-Q membranes also showed excellent cell-biocompatibility. Furthermore, compared with pure PCL nanofiber membrane, the PG-Q nanofiber membranes, especially PG-Q15 (QAS: 15 wt%) and PG-Q20 (QAS: 20 wt%), showed a considerable increase in the bacteriostatic rate of S. aureus and P. aeruginosa (more than 99% after 12 h). Therefore, electrospinning non-leaching antibacterial nanofiber membranes could be an optimal choice for antibacterial wound dressing.
Three-dimensional (3D) printing is a low-cost, high-efficiency production method, which can reduce the current cost and increase the profitability of skin repair material industry nowadays, and develop products with better performance. The 3D printing technology commonly used in the preparation of skin repair materials includes fused deposition molding technology and 3D bioprinting technology. Fused deposition molding technology has the advantages of simple and light equipment, but insufficient material selection. 3D bioprinting technology has more materials to choose from, but the equipment is cumbersome and expensive. In recent years, research on both technologies has focused on the development and application of materials. This article details the principles of fused deposition modeling and 3D bioprinting, research advances in wound dressings and tissue engineering skin production, and future developments in 3D printing on skin tissue repair, including cosmetic restoration and biomimetic tissue engineering. Also, this review prospects the development of 3D printing technology in skin tissue repairment.
Polymeric hydrogels have been widely researched as drug delivery systems, wound dressings and tissue engineering scaffolds due to their unique properties such as good biocompatibility, shaping ability and similar properties to extracellular matrix. However, further development of conventional hydrogels for biomedical applications is still limited by their poor mechanical properties and self-healing properties. Currently, nanocomposite hydrogels with excellent properties and customized functions can be obtained by introducing nanoparticles into their network, and different types of nanoparticles, including carbon-based, polymer-based, inorganic-based and metal-based nanoparticle, are commonly used. Nanocomposite hydrogels incorporated with polymeric micelles can not only enhance the mechanical properties, self-healing properties and chemical properties of hydrogels, but also improve the in vivo stability of micelles. Therefore, micelle-hydrogel nanocomposites have been recently considered as promising biomaterials. In this paper, the structure, properties and methods for preparation of the micelle-hydrogel nanocomposite systems are introduced, and their applications in drug delivery, wound treatment and tissue engineering are reviewed, aiming to provide reference for further development and application of the nanocomposites.