(65f) Hydrogel-Crosslinking By Minimally Invasive Surgical Modalities | AIChE

(65f) Hydrogel-Crosslinking By Minimally Invasive Surgical Modalities


Tasnim, T. - Presenter, University of Utah
Zhang, H. - Presenter, University of Utah
In this study, an enzymatic crosslinked hydrogel formation is triggered using temperature sensitive liposomes (TSLs). The process is performed by encapsulating an enzyme inside TSLs and releasing it at the phase transition temperature (Tm) of the TSLs. At Tm, TSLs passes through a melting phase transition from gel to a liquid-crystalline phase. This transition increases membrane permeability which results in the release of the encapsulated molecules. Most studies with TSLs have applied superficial heating at body temperature which suffers from poor localization of heating and eventually poor localization of the release content. To generate the localized and controlled release of the enzyme at 44°C, focused electromagnetic hyperthermia or focused ultrasound can be used. An injectable probe having accessibility to the subcutaneous layer is used to inject a liquid polymer solution at the injured spot. The liquid contains enzyme encapsulated TSLs, suspended in the Hyaluronic acid- Tyramine conjugate (HA-Tyr) and hydrogen peroxide solution. Our focused hyperthermia or ultrasound system can solidify the polymer solution injected inside the body by releasing the crosslinkers from TSLs. By this way, nonspecific heating and crosslinking along with traditional invasive surgery can be minimized. This site-specific, soft hydrogel formation can achieve minimally invasive short-term implant for tissue engineering and many other clinical applications.