Researchers in the UCLA Departments of Chemical Engineering, Bioengineering, and Radiological Sciences and the Pennsylvania State University Department of Chemical Engineering have developed a novel tissue adhesive hydrogel material for use in sealing wounds in stretchable tissues.
BACKGROUND:
Surgical sealants may be used as an alternative to sutures, for the sealing or reconnecting of ruptured tissues within the body. However, such sealants often suffer from poor mechanical strength in dynamic tissue environments, low adhesion, or cytotoxicity. Hydrogel materials derived from naturally occurring biopolymers are being developed to overcome the limitations of traditional surgical sealants. Although these hydrogels are biodegradable, they still require improvements in tissue adhesion and mechanical strength. The development of novel tissue adhesive hydrogels with increased stretchability for sealing dynamic tissues would significantly expand the range of surgical sealants.
INNOVATION:
UCLA and Pennsylvania State University researchers have invented a tough and stretchable adhesive hydrogel capable of sealing highly dynamic, stretchable tissues while maintaining its biodegradability. The hybrid hydrogel is comprised of biopolymers, and has improved mechanical strength over singe-component hydrogels. Specifically, this adhesive has four times higher stretchability and fracture toughness compared to pure GelMA. When sealing capacity was tested ex vivo in bladder and ureter models versus pure GelMA, the hybrid hydrogel adhesive increased both burst pressure for sealing a perforated bladder and failure energy to connect an anastomosed ureter. Overall, this tissue adhesive hydrogel has improved tissue sealing strength beyond all commercially available sealants, and has the potential to be used for applications in tissue engineering and regenerative medicine.
POTENTIAL APPLICATIONS:
• Tissue adhesive hydrogel for sealing highly dynamic, stretchable tissues
• Tissue engineering and regenerative medicine
ADVANTAGES:
• Four times higher stretchability (100%) and fracture toughness (~35 kJ/m3) than those for the pure GelMA
• Able to withstand 1500 kPa stress, compared to the 200 kPa of the pure GelMA
• Increased burst pressure for sealing a perforated bladder (5 kPa vs 2 kPa) and increased failure energy to connect an anastomosed ureter (0.015 J vs 0.002 J) compared to pure GelMA
• Increased tissue sealing strength beyond commercially available sealants
• Preserves the suitable properties of naturally-derived hydrogels (e.g., biodegradation) while improving the stretchability, toughness, and sealing properties
DEVELOPMENT-TO-DATE:
This technology has been evaluated for its mechanical and rheological properties. The hydrogel has also been tested for ex vivo sealing capacity using bladder and ureter models. The burst pressure of the hybrid hydrogel for sealing a perforated bladder was 5 kPa (vs 2 kPa for GelMA), and its failure energy to connect an anastomosed ureter was 0.015 J (vs 0.002 J for GelMA).
RELATED PAPERS:
1) N. Annabi, Y.-N. Zhang, A. Assmann, E.S. Sani, G. Cheng, A.D. Lassaletta, A. Vegh, B. Dehghani, G.U. Ruiz-Esparza, X. Wang, Engineering a highly elastic human protein–based sealant for surgical applications, Sci. Transl. Med. 9 (2017).
2) A. Assmann, A. Vegh, M. Ghasemi-Rad, S. Bagherifard, G. Cheng, E.S. Sani, G.U. Ruiz-Esparz, l. Noshadi, A.D. Lassaletta, S. Gangadharan , A. Tamayol , A. Khademhosseini , N. Annabi, A highly adhesive and naturally derived sealant. Biomaterials. 115 (2017).
3) J.-Y. Sun, X. Zhao, W.R.K. Illeperuma, O. Chaudhuri, K.H. Oh, D.J. Mooney, J.J. Vlassak, Z. Suo, Highly stretchable and tough hydrogels, Nature. 489 (2012).
4) J. Li, A.D. Celiz, J. Yang, Q. Yang, I. Wamala, W. Whyte, B.R. Seo, N. V Vasilyev, J.J. Vlassak, Z. Suo, D.J. Mooney, Tough adhesives for diverse wet surfaces, Science. 357 (2017).