Ideal hemostatic materials for the emergency rescue of war and traffic accident sufferers are essential to significantly control hemorrhage, reduce patient discomfort, and improve the survival ratio. However, most hemostats absorb blood quickly in contact with the wound; and then, adhere to blood clots, resulting in breaking scabs and tearing the wound when the materials are removed. Herein, an effective Janus amphipathic hemostatic dressing (Fiber@Gel/Ca 2+ /KL) with a fiber layer (polylactic acid/carboxymethyl chitosan) and a hydrogel layer (polyvinyl alcohol, carboxymethyl chitosan, Ca 2+ , and kaolin) is reported. Such a composite dressing unidirectionally drains the excessive serum from its hydrophobic side (fiber layer) to its hydrophilic side (hydrogel layer), so-called self-pumping, thereby further concentrating coagulated factors (including red blood cells and platelets). Further, Ca 2+ diffused from the hydrogel layer subsequently activates platelets and coagulation cascade. Besides, the Fiber@Gel/Ca 2+ /KL exhibits specific blood-clot anti-adhesion property on the fiber layer, making the dressing easily and safely peel off from the wound. It is believed that this novel hemostatic dressing with good hemostatic performance, easy clots removal, and excellent biocompatibility is expected to be used as a safe and efficient hemostatic dressing in clinical applications.
Pressure ulcer dressings with different functions can enhance wound healing ability to varying degrees; however, pressure ulcer dressings that integrate various functions and break the resistance of bacteria to traditional antibiotics have not been widely studied. We proposed a self-pumping/super-absorbent/transportable drug dressing (PLD-SLD), polycaprolactone (PCL)/sodium alginate (SA) was used to load platelet-derived growth factor (PDGF) and lidocaine hydrochloride (LID) by Janus electrospinning and self-assembly technology, and Ɛ-polylysine was used as a biological bacteriostatic agent to prepare a multi-layer dressing. SEM showed that the dressing had a fluffy structure. The dressing can pump the exudate to the SA layer away from the skin. The swelling ratio reached 1378.667 ± 44.752 %. Coagulate blood in 5 min. On the 8th day, the unclosed area rate of the PLD-SLD dressing group was 16.112 ± 0.088 % lower than that of the model group. Importantly, the dressing can induce the expression of CD31, VEGF, α-SMA, and reduce the expression of CD68, thereby giving priority to wound healing. There was no scar formation after healing. In this study, a new dressing preparation method was proposed for the problems of exudate management, infection control, pain relief and healing promotion of stage 3–4 pressure ulcer healing.