Elastic Janus film for Wound Dressings: Unidirectional Biofluid Transport and Effectively Promoting Wound Healing

Abstract

The intrinsic hydrophilicity of conventional dressings cannot achieve effective management of excessive biofluid around the wound bed, which inevitably causes infection and hinders wound healing. In addition, present dressings such as medical gauze or band aids have a limited stretching capability, which does not comply well with the skin deformation during muscle movement, thus impacting patient comfort. Herein, a Janus wound dressing is reported by assembling an external hydrophobic (HP) adhesive tape, a filter paper, and a polydimethylsiloxane (PDMS) Janus film. The PDMS Janus film as the primary dressing can unidirectionally remove biofluid away from the wound bed. The mechanism of the unidirectional biofluid transport is investigated, demonstrating that the stretching or bending of the Janus dressing is beneficial for unidirectional biofluid draining. It indicates that the Janus PDMS film has potential for practical applications on stretched or bended skin surface. In addition, in order to prevent bacterial infection, amoxicillin powder is uniformly encapsulated on the HP layer of Janus film, resulting in faster wound healing. This study is valuable for designing and fabricating next-generation dressings with high performance for clinical applications.

Multifunctional “Janus‐Type” Bilayer Films Combine Broad‐Range Tissue Adhesion with Guided Drug Release

“…Our observations over a time span of 14 days reveal that Janus-type bilayer film treatment accelerates the healing process, which is in line with the results obtained from the in vitro tests: when wounds treated with films are compared to those of the untreated group, an improvement of the wound healing process is observed on the 14th postoperative day (Figure 5a, right). Compared to other materials tested for wet tissue adhesive applications, [16,[65][66][67] the wound healing performance of the Janus-type bilayer films presented here is quite promising since the material itself promotes wound closure without the need of adding a stimulating agent such as growth factors.…”

“…To cope with this problem, medical materials with asymmetric functionalities were recently introduced, and they were indeed successful in promoting tissue repair in vivo. [22][23][24][25] For example, Cui et al [22] presented a Janus structure with oppositely charged surfaces, which enables the overall material to seal tissue perforations and-at the same time-prevents undesired adhesions to its exterior part. Very recently, a three-layered Janus adhesive with asymmetric wetting properties developed by Xu et al [23] was found to be successful in keeping the wound area dry while absorbing the wound exudate.…”

“…[22][23][24][25] For example, Cui et al [22] presented a Janus structure with oppositely charged surfaces, which enables the overall material to seal tissue perforations and-at the same time-prevents undesired adhesions to its exterior part. Very recently, a three-layered Janus adhesive with asymmetric wetting properties developed by Xu et al [23] was found to be successful in keeping the wound area dry while absorbing the wound exudate. Other very recent and highly promising examples from this area are peritoneuminspired porous poly(vinyl alcohol) (PVA) hydrogels for canalizing cellular growth at the desired site, [26] and double-layered (ionically and covalently cross-linked) alginate/chitosan films for advanced tendon healing.…”

Multifunctional fibrous wound dressings for refractory wound healing

“…Xu et al utilized femtosecond laser micro-drilling technology to prepare PDMS Janus wound dressings containing the anti-inflammatory drug amoxicillin. 162 The dressing has excellent bendability or stretchability and unidirectional liquid transport. Benefiting from anti-inflammatory and antibacterial functions, it resulted in faster wound healing.…”

Wearable Bioelectronics for Chronic Wound Management

“…In addition, wound fluid collection and in situ sampling can be greatly improved by newly developed fabrication techniques such as microfluidics patterns. [116,[137][138][139][140][141]…”