Icy core-shell composite nanofibers with cooling, antibacterial and healing properties for outdoor burns.

Burns are usually difficult to treat because their susceptibe to bacterial infections. When burns is accompanied by hyperthermia, the heat accumulated on the skin will causes extensive tissue damage. Most dressings focus on the treatment process, while ignoring the first-aid treatment to remove hyperthermia. To make matters worse, when outdoors, it is hard to find clean water to wash and cool the burned area. A dressing which can simultaneously realize first-time cooling and repairing treatment of the burned area can shorten treatment time, and is especially beneficial for outdoor use. In this study, a handheld coaxial electrospinning device is developed for preparing platelet-rich plasma @Polycaprolactone-epsilon polylysine (PRP@PCL/ε-PL) core-shell nanofibers. The nanofibers can be synchronously transformed into ice fibers during the spinning process, and directly deposited on the skin. The whole process is convenient to use outdoor. Via dual cooling mechanisms, first aid can take away the excessive heat in the burn area by nanofibers. These core-shell nanofibers also show its excellent antimicrobial and tissue regeneration-promoting properties. Therefore, it achieves first-time cooling and repair treatment of the burned area at the same time. Moreover, due to direct in-situ deposition of this handheld coaxial electrospinning, better antimicrobial properties, and faster healing performance are achieved. By using this integrated strategy that combines cooling, antibacterial and healing promotion, the burn recovery time is shortened from 21 days to 14 days.

Cool and hot chitosan/platelet-derived growth factor nanofibers for outdoors burns.

Burns and scalds are thermal injuries caused by a large amount of heat accumulation in local tissues. The first cooling emergency is a key step. However, it is hard that in outdoors to find clean water to cool the scald tissue sites. Moreover, most dressings are concentrated on the treatment process today, neglecting the emergency treatment of temperature reduction. In this study, we imported refrigeration in the electrospinning process while using dirty water, rainwater and even urine of outdoors, so that the cooled sterile fibers were directly deposited on the burn and scald wounds, and the cooling emergency was achieved through the dual cooling mechanism. Since this fiber which is made up of cheap fish gelatin contains CuS adopting the green method, it can generate heat and effectively kill bacteria under the irradiation of an illumination lamp at the front end of a spinning device. As a result of the direct deposition, there is an excellent fit between the fibrous membrane and the skin, which reduces the air gap to achieve a better and quick cooling and heating effects. On the same Chitosan/Platelet-derived Growth Factor fiber membrane, this method of cooling first and heating second can shorten the recovery time from 30 days to 21 days. Thus, this treatment strategy has a great potential application prospect in the field of outdoor burn treatment.

Synergistic antibacterial polyacrylonitrile/gelatin nanofibers coated with metal-organic frameworks for accelerating wound repair.

Bacterial infections prolong the wound healing time and increase the suffering of patients, thus it is important to develop wound dressing that can inhibit bacterial infection. Herein, we use two methods including "doping method" and "secondary growth method" to prepare ZIF-8@gentamicin embedded in and coated on polyacrylonitrile/gelatin (PG) nanofibers, separately. Composite nanofibers prepared by the secondary growth method achieve higher drug loading than that of the doping method, and the release rate can be adjusted by pH. Simultaneously increasing drug loading and regulating its release rate are achieved in the secondary growth method, which cannot be achieved by the doping method. Furthermore, synergistic antibacterial property occurs in the composite nanofibers prepared by the secondary growth method, and gentamicin loaded on ZIF-8 promotes the antibacterial effect, which shows better antibacterial effect than the doping method. As a result, during the wound infection of mouse, composite nanofibers prepared by the secondary growth method exhibit a faster recovery effect than the doping method, which effectively shortened the wound healing time from 21 days to 16 days.

(5-Bromo-2-hydroxy-phen-yl)(phen-yl)methanone.

In the title compound, C(13)H(9)BrO(2), the mol-ecular conformation is stabilized by an intra-molecular O-H⋯O hydrogen bond. In the crystal structure, weak inter-molecular C-H⋯O hydrogen-bonding inter-actions link the mol-ecules into chains along the c-axis direction.

2-(4-Phenyl-3H-1,5-benzodiazepin-2-yl)phenol.

In the title compound, C(21)H(16)N(2)O, the dihedral angle between the pendant aromatic rings is 74.2-(1)°.. The conformation is stabilized by an intramolecular O-H⋯N hydrogen bond.