In situ Forming Systems for Wound Healing: A Review

In-situ forming systems are liquid or viscous injectable materials that after being injected into the body, due to mixing with reactive substances or in response to new conditions (temperature, pH, presence of special molecules or ions, visible or ultraviolet light radiation), they formed a semi-solid material or gel. In the recent years, due to the unique characteristics of in situ forming systems, preparation and investigation of these systems for wound healing have gained increasing attentions. In addition to easy and non-invasive injection of in situ forming systems, these materials can completely fill irregular wound defects and adhere to the wound edge tissues. Also these materials can simultaneously act as a controlled drug delivery system, cell carrier/tissue scaffold, hemostatic agent and tissue-adhesive. Until now, several physical, chemical and enzymatically cross-linking methods have been used to prepare in situ forming systems/hydrogels. In this review, various emerging and innovative approaches being developed and utilized for the preparation of in situ forming systems/hydrogels for wound dressing are reviewed. Also challenges and future prospects of these systems are discussed.