Recent advances in the preventative strategies for postoperative adhesions using biomaterial-based membranes and micro/nano-drug delivery systems

Postoperative adhesions are one of the clinically significant complications of almost all surgeries, leading to lifelong problems. To date, three strategies have been introduced to prevent or reduce the formation of these fibrous bands, including implementation of physical barriers, local or systemic administration of pharmacological agents, or a combination of both at the site of postsurgical traumatized tissue. This so far unsolved challenge has prompted scientists to focus on developing more effective preventative therapies. In this review, we aimed to provide a detailed overview of drug-free and drug-incorporated anti-adhesion barrier membranes and micro/nano-drug delivery systems implemented for postoperative adhesion prevention. The formulation components, the mean particle sizes of the particulate-based systems, release behavior of pharmacologic agents, and various evaluation methods determining the in vivo efficacy of the prepared systems in animal models including scoring, gross evaluation, Western blot, polymerase chain reaction (PCR), tissue scanning electron microscopy (SEM), enzyme-linked immunosorbent assay (ELISA), histological and immunohistochemical analyses were identified and discussed. Although a great number of studies have focused on the preparation and evaluation of the anti-adhesion efficacy of drug-free or drug-loaded anti-adhesion systems, further sophisticated research is required to develop effective and safe anti-adhesion products for clinical application.