title: In vivo experimental aneurysm embolization in a swine model with a liquid-to-solid gelling polymer system: initial biocompatibility and delivery strategy analysis.
abstract: OBJECTIVE
  Current treatments for cerebral aneurysms are far from ideal. Platinum coils are prone to compaction, and currently used liquid embolics are delivered with angiotoxic agents. This work presents initial in vivo studies of a novel liquid-to-solid gelling polymer system (PPODA-QT), focusing on biocompatibility and effective delivery strategies.
  
  
  METHODS
  PPODA-QT was used to embolize surgically created lateral wall carotid artery aneurysms in swine using three delivery strategies. Group 1 aneurysms were completely filled with PPODA-QT (n = 5), group 2 aneurysms were subcompletely (80%-90%) filled (n = 3), and group 3 aneurysms underwent three-dimensional coil placement followed by polymer embolization (n = 3). The study was designed such that three animals per treatment group survived to 1 month.
  
  
  RESULTS
  The group 1 delivery strategy (100% filling) resulted in survival of 3/5 animals. This strategy led to aneurysm stretching, which resulted model failure in 2/5 animals. Group 2 aneurysms, although initially <100% filled with the polymer, displayed robust neointimal tissue coverage and complete obliteration after 1 month. Group 3 aneurysms showed less prominent neointimal tissue coverage as well as two instances where excess polymer was found in the parent vessel. The PPODA-QT material showed good biocompatibility with vascular tissue in all animals at 1 month.
  
  
  CONCLUSIONS
  This small-scale pilot study highlighted first-time in vivo use of PPODA-QT as an embolic agent for aneurysm treatment. Filling aneurysms to 80% to 90% capacity proved to be a safe and effective delivery strategy, and PPODA-QT showed excellent biocompatibility. This study indicates that future investigation of PPODA-QT for aneurysm embolization is warranted, as it may prove to be a viable alternative to current embolic materials.
authors: Center for Interventional Biomaterials, School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ, USA. Celeste.Riley@asu.edu
authors: Celeste R
authors: CR
authors: Brennecka
authors: Mark C
authors: MC
authors: Preul
authors: William D
authors: WD
authors: Bichard
authors: Brent L
authors: BL
authors: Vernon
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry / Q000494:pharmacology; D002340:Carotid Artery Diseases / Q000628:therapy*; D003432:Cross-Linking Reagents / Q000494:pharmacology; D004195:Disease Models, Animal; D016503:Drug Delivery Systems / Q000379:methods; D004621:Embolization, Therapeutic / Q000379:methods*; D005782:Gels; D002532:Intracranial Aneurysm / Q000628:therapy*; D008422:Materials Testing; D044367:Phase Transition; D010865:Pilot Projects; D011108:Polymers / Q000737:chemistry / Q000494:pharmacology*; D011409:Propylene Glycols / Q000737:chemistry / Q000494:pharmacology*; D015996:Survival Rate; D013552:Swine
chemical_list: D001672:Biocompatible Materials; D003432:Cross-Linking Reagents; D005782:Gels; D011108:Polymers; D011409:Propylene Glycols; C012504:polypropylene glycol