湿润烧伤膏联合3M液体敷料治疗新生儿尿布皮炎的效果观察

目的:探讨湿润烧伤膏联合3M液体敷料治疗新生儿尿布皮炎的临床疗效。方法:对我院110例新生儿尿布皮炎患儿进行临床对照试验研究,使用硬币投掷法将患儿随机分为对照组(单独使用湿润烧伤膏)和试验组(湿润烧伤膏联用3M液体敷料),比较两组患儿治疗3 d时临床疗效、疼痛程度及不良反应。结果:试验组患儿创面愈合时间显著低于对照组患儿(P<0.05);试验组患儿疼痛程度2级、3级、4级人数少于对照组;两组患儿临床疗效比较,试验组治愈人数显著高于对照组(P<0.05);试验组患儿皮肤机械性损伤、继发过敏性皮炎的发生率显著低于对照组患儿(P<0.05)。结论:湿润烧伤膏联合3M液体敷料治疗新生儿尿布皮炎的临床疗效明显,可以显著改善患儿疼痛状况,减少临床不良事件发生率。     

Wound dressing composed of hyaluronic acid and collagen containing EGF or bFGF: comparative culture study

We developed a novel wound dressing composed of a hyaluronic acid (HA) and collagen (Col) spongy sheet containing epidermal growth factor (EGF) or basic fibrolast growth factor (bFGF) by freeze-drying method (EGF-wound dressing or bFGF-wound dressing, respectively). A wound dressing without any growth factor was prepared as a control in a similar manner as above (C-wound dressing). Intermolecular cross-linkage between Col molecules was induced by UV irradiation. The release behavior of free HA from the wound dressing was investigated using a C-wound dressing. The weight of C-wound dressing after 1 day, 3, 5, and 7?days of incubation on top of a Col gel sheet at the air–water interface (wound surface model) was 55, 36, 30, and 19% of the original weight, respectively. Most free HA and a part of Col was released from the cross-linked Col network in the wound dressing during incubation, as the original Col content in the wound dressing was 33%. Next, fibroblast proliferation was assessed in conventional culture medium preconditioned by immersion of a piece of C-, EGF-, or bFGF-wound dressing, i.e. C-conditioned medium, EGF-conditioned medium, or bFGF-conditioned medium. Cell proliferation in C-conditioned medium increased to approximately the same level as that in conventional medium. Cell proliferation in EGF- and bFGF-conditioned medium was 1.9 times and 2.6 times greater than that in conventional medium after 7?days of cultivation, respectively. Finally, cytokine production of fibroblasts was assessed in a wound surface model using a fibroblast-incorporating Col gel sheet (cultured dermal substitute [CDS]). CDS was elevated to the air–medium interface, on which each wound dressing was placed and cultured for 7?days. Fibroblasts in CDS covered with EGF-wound dressing released 3.6 times more vascular endothelial growth factor (VEGF) and 4.6 times more hepatocyte growth factor (HGF) when compared with the C-wound dressing. Fibroblasts in CDS covered with bFGF-wound dressing released 10.2 times more VEGF and 6.3 times more HGF when compared with the C-wound dressing. This finding indicates that bFGF-wound dressing can facilitate more effectively the VEGF and FGF production compared with EGF-wound dressing.     

Polyvinyl pyrrolidone/carrageenan blend hydrogels with nanosilver prepared by gamma radiation for use as an antimicrobial wound dressing

Hydrogels were prepared using polyvinyl pyrrolidone (PVP) blended with carrageenan by gamma irradiation at different doses of 25 and 40 kGy. Gel fraction of hydrogels prepared using 10 and 15% PVP in combination with 0.25 and 0.5% carrageenan was evaluated. Based on gel fraction, 15% PVP in combination with 0.25% carrageenan and radiation dose of 25 kGy was selected for the preparation of hydrogels with nanosilver. Radiolytic synthesis of silver nanoparticles within the PVP hydrogel was carried out. The hydrogels with silver nanoparticles were assessed for antimicrobial effectiveness and physical properties of relevance to clinical performance. Fluid handling capacity (FHC) for PVP/carrageenan was 2.35 ± 0.39–6.63 ± 0.63 g/10 cm² in 2–24 h. No counts for Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, and Candida albicans were observed in the presence of hydrogels containing 100 ppm nanosilver after 3–6 h. The release of silver from hydrogels containing 100 ppm nanosilver was 20.42 ± 1.98 ppm/100 cm² in 24 h. Hydrogels containing 100 ppm nanosilver with efficient FHC demonstrated potential microbicidal activity (≥3 log₁₀ decrease in CFU/ml) against wound pathogens, P. aeruginosa, S. aureus, E. coli, and C. albicans. PVP/carrageenan hydrogels containing silver nanoparticles can be used as wound dressings to control infection and facilitate the healing process for burns and other skin injuries.     

Pectin-chitosan-PVA nanofibrous scaffold made by electrospinning and its potential use as a skin tissue scaffold

Scaffolds made of chitosan nanofibers are often too mechanically weak for their application and often their manufacturing processes involve the use of harmful and flammable organic solvents. In the attempt to improve the mechanical properties of nanofibrous scaffolds made of chitosan without the use of harmful chemicals, pectin, an anionic polymer was blended with chitosan, a cationic polymer, to form a polyelectrolyte complex and electrospun into nanofibers for the first time. The electrospun chitosan-pectin scaffolds, when compared to electrospun chitosan scaffolds, had a 58% larger diameter, a 21% higher Young’s modulus, a 162% larger strain at break, and a 104% higher ultimate tensile strength. Compared to the chitosan scaffolds, the chitosan-pectin scaffolds’ swelling ratios decreased by 55% after 60?min in a saline solution and more quickly released the preloaded tetracycline HCl. The L929 fibroblast cells proliferated slightly slower on the chitosan-pectin scaffolds than on the chitosan scaffolds. Nonetheless, cells on both materials deposited similar levels of extracellular type I collagen on a per DNA basis. In conclusion, a novel chitosan-pectin nanofibrous scaffold with superior mechanical properties than a chitosan nanofibrous scaffold was successfully made without the use of harmful solvents.     

Controlling Fibroblast Proliferation with Dimensionality-Specific Response by Stiffness of Injectable Gelatin Hydrogels

Abstract

We report an injectable hydrogel system with tunable stiffness for controlling the proliferation rate of human fibroblasts (HFF-1) in both two-dimensional (2D) and three-dimensional (3D) culture environments for potential use as a wound dressing material. The hydrogel composed of gelatin–hydroxyphenylpropionic acid (Gtn–HPA) conjugate was formed by the oxidative coupling of HPA moieties catalyzed by hydrogen peroxide (H₂O₂) and horseradish peroxidase (HRP). The stiffness of the hydrogels was controlled well by varying the H₂O₂ concentration. The effects of hydrogel stiffness on the proliferation rate of HFF-1 in both 2D and 3D were investigated. We found that the proliferation rate of HFF-1 using Gtn–HPA hydrogels was strongly dependent on the hydrogel stiffness, with a dimensionality-specific response. In the 2D studies, the HFF-1 exhibited a higher proliferation rate when the stiffness of the hydrogel was increased. In contrast, the HFF-1 cultured inside the hydrogel remained non-proliferative for 12 days before a stiffness-dependent proliferation profile was shown. The proliferation rate decreased with an increase in stiffness of the hydrogel in a 3D culture environment, unlike in a 2D environment.     

Porosity and biological properties of polyethylene glycol-conjugated collagen materials

Collagen-based materials can be designed for use as scaffolds for connective tissue reconstruction. The goal of the present study was to evaluate the behavior of collagen materials as well as cell and tissue reactions after the conjugation of activated polyethylene glycols (PEGs) with collagen. It is known that proteins conjugated with PEGs exhibit a decrease in their biodegradation rate and their immunogenicity. Different concentrations and molecular weights of activated PEGs (PEG-750 and PEG-5000) were conjugated to collagen materials (films or sponges) which were then investigated by collagenase assay, fibroblast cell culture, and subcutaneous implantation. PEG-conjugated collagen sponge degradation by collagenase was delayed in comparison to untreated sponges. In culture, fibroblasts with a normal morphology reached confluency on PEG-conjugated collagen films. In vivo, the porous structure of non-modified sponges collapsed by day 15 with a few observable fibroblasts between the collagen fibers. In PEG-modified collagen sponges, the porous structure remained stable for 30 days. Cell infiltration was particularly enhanced in PEG-750-conjugated collagen sponges. In conclusion, PEGs conjugated onto collagen sponges stabilize the porous structure without deactivating the biological properties of collagen. These porous composite materials could function as a scaffold to organize tissue ingrowth.     

Release from alginate enhances the biological activity of vascular endothelial growth factor

A primary factor which limits engineering tissues of substantial size is the lack of nutrients readily available to transplanted cells. One potential solution to this nutrient limitation is to encourage the rapid development of a vascular network within three-dimensional tissue engineering matrices. Vascular endothelial growth factor (VEGF) has been identified as a potent stimulator of angiogenesis in vivo. Though effective at stimulating endothelial cells to form blood vessels VEGF degrades rapidly. Spherical alginate beads (3.3±0.1 mm diameter) were examined as a means of delivering biologically functional VEGF at a controlled rate over extended times. The alginate beads demonstrated the ability to incorporate VEGF with an efficiency between 30 and 67%, depending on the processing conditions, and release it at a constant rate (5%/day) for up to 14 days in vitro. The released VEGF, when assayed for its ability to stimulate endothelial cells in culture, was found not only to be functional but more potent (three to five times) than the same mass of VEGF added directly to the culture medium. The release kinetics of freeze dried VEGF containing alginate beads were also examined and found to be comparable to non-freeze dried samples.     

湿性敷料联合持续微氧渗透创面治疗技术在慢性伤口中的应用效果

目的:探讨湿性敷料联合持续微氧渗透创面治疗技术在慢性伤口中的应用效果。方法:选择2019年3月—2020年3月在某院治疗的慢性伤口病人27例,随机分为对照组13例和观察组14例。根据两组病人住院期间的病情特点拟订个体化的治疗方案,对照组使用湿性愈合伤口管理方法对伤口进行管理,观察组在此基础上应用持续微氧渗透创面治疗技术伤口管理方法对伤口进行管理。治疗1个疗程即28 d后比较两组病人伤口的愈合程度、伤口治疗有效时间、28 d内伤口换药次数及伤口的疼痛程度。结果:观察组病人治疗1个疗程后伤口愈合程度明显优于对照组,伤口治疗有效时间明显短于对照组,换药次数明显少于对照组(P<0.01)。观察组病人治疗第14天、第28天的VAS评分明显低于对照组(P<0.01)。结论:湿性敷料联合持续微氧渗透创面治疗技术可明显提高慢性伤口的愈合率,有效缓解疼痛,缩短愈合时间。     

Protection of an intraoral surgical wound with a new dressing: a randomised controlled clinical trial

Operations that involve the maxillofacial region often require intraoral incisions, and contamination of these wounds is common as a result of the presence of saliva, plaque, and food debris. Postoperative infection is therefore common. The aim of the study was to evaluate the clinical efficacy of an intraoral dressing material, Reso-Pac®, in improving postoperative comfort for patients and its effect on wound healing. One hundred patients who required removal of impacted mandibular third molars were recruited, and were randomised into two groups (50 in each). A standardised surgical technique was used for removal of the impacted teeth, and wounds were closed with sutures. Postoperatively, the study group was given Reso-Pac® dressing while the control group was not. Postoperative pain was measured using a visual analogue scale (VAS). Wound healing was assessed with the help of Landry’s scale, and we also measured thermal sensitivity. Data were analysed using the paired t test. The results in the study group were significantly better than those in the control group (p < 0.001). Reso-Pac® promoted wound healing and improved patients’ comfort during the postoperative phase.     

以硝化纤维为膜材的伤口敷料的制备及处方优化

目的 制备一种以硝化纤维为膜材的创伤敷料,并对其处方进行优化。方法 对市售产品进行部分分析,采用硝化纤维作为成膜材料,以苯甲醇为抑菌剂,蓖麻油为增塑剂,棕榈酸异丙酯为皮肤柔润剂,樟脑作为芳香剂,以异丙醇、乙酸乙酯、乙酸丁酯为挥发溶剂制备创伤敷料。分别对所成膜的抗张强度、断点伸长百分率、透气防水性能等进行考察评价。结果 所制备液体创伤敷料成膜性能良好,确定硝化纤维的最终使用量为6%、蓖麻油的使用量为4%。结论 研究所制得的液体创伤敷料成膜性好,有良好的机械性能,并具备较好的防水能力及一定的透气性能。