Minimally Invasive Precise Application of Bioadhesives to Prevent IPPROM on a Pregnant Sheep Model

<b><i>Introduction:</i></b> Iatrogenic preterm premature rupture of the membrane remains the Achille’s heel of fetoscopy. The aim of this study was to show in vivo feasibility of fetal membrane (FM) defect sealing by the application of tissue glues with umbrella-shaped receptors. <b><i>Methods:</i></b> First, we adapted our previously described ex vivo strategy and evaluated the adhesion strength of different tissue glues, Histoacryl® and Glubran2®, by bonding polytetrafluoroethylene or silicone encapsulated nitinol glue receptor to human FM. Then, we exposed pregnant sheep uterus through a laparotomy and placed a 10-French trocar into the amniotic cavity through which the umbrella-shaped glue receptor (<i>n</i> = 9) was inserted and fixated onto the FM with the tissue glues (<i>n</i> = 8). The tightness of the sealed defects was assessed 4 h post-surgery. <b><i>Results:</i></b> Both tissue glues tested resulted in adhesion of the glue receptors to the FM ex vivo. In vivo, all glue receptors opened in the amniotic cavity (<i>n</i> = 9) and all successfully placed glue receptors sealed the FM defect (<i>n</i> = 8). Four hours post-surgery, 2 treatment sites showed minimal leakage whereas the negative control without glue (<i>n</i> = 1) showed substantial leakage. <b><i>Discussion:</i></b> This in vivo study confirms that fetoscopically induced FM defects can be sealed by the application of tissue adhesives.

Injectable Hydrogel Based on Modified Gelatin and Sodium Alginate for Soft-Tissue Adhesive

To assist or replace the traditional suture techniques for wound closure, soft-tissue adhesives with excellent adhesion strength and favorable biocompatibility are of great significance in biomedical applications. In this study, an injectable hydrogel tissue adhesive containing adipic acid dihydrazide–modified gelatin (Gel-ADH) and oxidized sodium alginate (OSA) was developed. It was found that this tissue adhesive possessed a uniform structure, appropriate swelling ratio, good injectability, and excellent hemocompatibility and cytocompatibility. The adhesion capacity of the developed adhesive with optimized component and concentration was stronger than that of the commercial adhesive Porcine Fibrin Sealant Kit. All these results suggested that the developed hydrogel was a promising candidate for a soft-tissue adhesive.

Applications of Bioadhesives: A Mini Review

Bioadhesives have demonstrated their superiority in clinical applications as tissue adhesives, hemostats, and tissue sealants. Because of the intrinsic stickiness, the applications have been expanded to various areas, such as functional wound dressing, factor delivery vehicles, and even medical device fixation. While many literature works discussed the mechanism of bioadhesives, few of them specifically summarized the applications of bioadhesives. To fill in the blanks, this review covers recent research articles and focuses precisely on the applications of bioadhesives which can be generally classified as follows: 1) wound closure, 2) sealing leakage, and 3) immobilization, including those already in the clinic and those showing great potential in the clinic. It is expected that this article will provide a whole picture on bioadhesives’ applications and lead to innovations in the application of bioadhesives in new fields.