A review on in situ gels as polymer drug carriers in the treatment of periodontitis

The “in situ gel” system has become one of the emerging drug delivery systems and plays a significant role in the treatment of periodontitis. The “sol–gel” transition has distinct characteristics that respond to physiological stimulation, enabling a controlled and sustained drug release, thus offering various advantages over traditional mechanical and systemic drug delivery methods. In oral drug delivery systems, in situ gels are commonly based on four main types: thermosensitive, pH-triggered, ion-induced, and solvent-exchange in situ gels. Polymers have been used in in situ gel formulations and maintain their potential in periodontal drug delivery. Different types of polymers are commonly used in four types of in situ gel formulations, such as poloxamer, carbopol, bleached shellac (BS), chitosan, and hydroxypropyl methylcellulose (HPMC). To understand the important role of in situ gel as a polymer drug carrier in drug release and evaluate its therapeutic effect on periodontitis, this article reviews the sol–gel transition mechanism of four main stimulation types of in situ gel, the effects of different in situ gel-forming polymer materials on the properties of in situ gel, and the latest research progress in in situ gel application in the treatment of periodontitis. The effectiveness of in situ gels for the treatment of periodontitis and the influence of various polymers on the overall properties of in situ gels were evaluated, providing new ideas and methods for the treatment of periodontitis in terms of the summary of research progress and also providing valuable experience for the design and development of in situ gels.

Graphical abstract