Image: A hemostatic hydrogel similar to Jell-O solidifies in wounds to control bleeding (Photo courtesy of TAMU).
An injectable hydrogel based on kappa-carrageenan (κCA), a natural polysaccharide commonly used as a thickening agent for pastries, can facilitate wound healing, claims a new study.
Developed by researchers at Texas A&M University (TAMU; College Station, TX, USA), the nanoengineered hemostatic hydrogel consist of a κCA gel loaded with synthetic two-dimensional nanosilicates. The nanosilicates, which are similar to clay, hold an ionic charge, thus increasing protein adsorption; this results in enhanced cell adhesion and spread, increased platelet binding, and reduced bloodclotting time. In addition, the nanosilicates allow a range of therapeutic biomacromolecules to be delivered in a sustained manner.
The addition of the nanosilicates also significantly suppresses the release of vascular endothelial growth factor (VEGF) and facilitates tissue regeneration and wound healing. By controlling the ratio between κCA and the nanosilicates, the compressive stiffness of the crosslinked hydrogel can be modulated between 20 and 200 kPa. But even at such high mechanical stiffness, the hydrogel remains highly porous with the interconnected network. The study was published on February 7, 2018, in Acta Biomaterialia.
“Interestingly, we also found that these injectable bandages can show a prolonged release of therapeutics that can be used to heal the wound,” said lead author graduate student Giriraj Lokhande, MSc, of the department of biomedical engineering. “The negative surface charge of nanoparticles enabled electrostatic interactions with therapeutics, thus resulting in the slow release of therapeutics.”
“Injectable hydrogels are promising materials for achieving hemostasis in case of internal injuries and bleeding, as these biomaterials can be introduced into a wound site using minimally invasive approaches,” concluded senior author Akhilesh Gaharwar, PhD. “An ideal injectable bandage should solidify after injection in the wound area and promote a natural clotting cascade. In addition, the injectable bandage should initiate wound healing response after achieving hemostasis.”
Hemorrhage is a leading cause of death in the battlefield, as well as during surgical anastomosis and percutaneous interventions. In addition, approximately 25% of potentially survivable deaths result from uncontrolled junctional bleeding, the leading cause of preventable death in combat and the top focus of tactical medicine. Over 800 U.S. military personnel have been hospitalized with these types of injuries during the wars in Iraq and Afghanistan. Of these, more than 150 suffered from upper extremity injuries, 25 of who died from their wounds.
Texas A&M University