慢性伤口是全世界严重关注的问题,通常与细菌感染有关。随着细菌感染患病率的增加,寻找替代方案至关重要。精油(EO)由于其强大的抗炎作用,成为抗生素的有希望的选择,镇痛药,抗氧化和抗菌性能。然而,这样的化合物呈现高挥发性。为了解决这个问题,设计了一种由同轴湿纺纤维组成的药物输送系统,即丁香油(CO),肉桂叶油(CLO)和茶树油(TTO),已加载。简而言之,由两个注射泵组成的同轴系统,去离子水的凝固浴,使用圆柱形收集器和同轴喷丝头。将10%w/v聚己内酯(PCL)溶液与不同的EOs以2×最低杀菌浓度(MBC)混合,并装入连接到内部端口的注射器中。而10%w/v醋酸纤维素(CA)溶液与10%w/v聚乙二醇(PEG)以90:10%v/v的比例混合(以增加纤维弹性)被装载到连接到外部端口的注射器。该层被用作屏障以加快截留的EO的释放。CA在水凝固浴中的固有孔隙率允许进入纤维芯。CA还与10%w/v聚乙二醇(PEG)以90:10%v/v(CA:PEG)的比例混合,增加纤维的弹性。微纤维在生理样环境中孵育28天期间保持其结构完整性。在机械评估中,它们还显示出高的弹性(最大断裂伸长率>300%)和抗破裂性,达到质量损失仅为≈2.29%-57.19%。EO以延长和持续的方式从纤维中释放,其中约30%的EO在生理样培养基中孵育24小时内释放,对金黄色葡萄球菌有很好的抗菌效果,表皮葡萄球菌,大肠杆菌和铜绿假单胞菌,慢性伤口中最常见的细菌。此外,超细纤维表现出有效的抗氧化作用,呈现高达59%的2,2-二苯基-1-吡啶酰肼(DPPH)活性减少。此外,同轴系统被认为与成纤维细胞和人类角质形成细胞接触是安全的,培养48小时后达到代谢活性高于80%。数据证实了工程系统用于慢性伤口的潜在治疗的适用性。
Chronic wounds represent a serious worldwide concern, being often associated with bacterial infections. As the prevalence of bacterial infections increase, it is crucial to search for alternatives. Essential oils (EOs) constitute a promising option to antibiotics due to their strong anti-inflammatory, analgesic, antioxidant and antibacterial properties. However, such compounds present high volatility. To address this issue, a drug delivery system composed of coaxial wet-spun fibers was engineered and different EOs, namely clove oil (CO), cinnamon leaf oil (CLO) and tea tree oil (TTO), were loaded. Briefly, a coaxial system composed of two syringe pumps, a coagulation bath of deionized water, a cylindrical-shaped collector and a coaxial spinneret was used. A 10 % w/v polycaprolactone (PCL) solution was combined with the different EOs at 2 × minimum bactericidal concentration (MBC) and loaded to a syringe connected to the inner port, whereas a 10 % w/v cellulose acetate (CA) solution mixed with 10 % w/v polyethylene glycol (PEG) at a ratio of 90:10 % v/v (to increase the fibers\' elasticity) was loaded to the syringe connected to the outer port. This layer was used as a barrier to pace the release of the entrapped EO. The CA\'s inherent porosity in water coagulation baths allowed access to the fiber\'s core. CA was also mixed with 10 % w/v polyethylene glycol (PEG) at a ratio of 90:10 % v/v (CA:PEG), to increase the fibers\' elasticity. Microfibers maintained their structural integrity during 28 days of incubation in physiological-like environments. They also showed high elasticities (maximum elongations at break >300 %) and resistance to rupture in mechanical assessments, reaching mass losses of only ≈ 2.29 % - 57.19 %. The EOs were released from the fibers in a prolonged and sustained fashion, in which ≈ 30 % of EO was released during the 24 h of incubation in physiological-like media, demonstrating great antibacterial effectiveness against Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli and Pseudomonas aeruginosa, the most prevalent bacteria in chronic wounds. Moreover, microfibers showed effective antioxidant effects, presenting up to 59 % of reduction of 2,2-diphenyl-1-picrylhydrazyl (DPPH) activity. Furthermore, the coaxial system was deemed safe for contact with fibroblasts and human keratinocytes, reaching metabolic activities higher than 80 % after 48 h of incubation. Data confirmed the suitability of the engineered system for potential therapeutics of chronic wounds.