title: Poloxamer-based hydrogels hardening at body core temperature as carriers for cell based therapies: in vitro and in vivo analysis.
abstract: Cell-based regenerative therapies for bone defects usually employ bone precursor cells seeded on solid scaffolds. Thermosensitive hydrogels that harden at body core temperature are promising alternative cell carriers as they are applicable minimally invasively. We modified Pluronic® P123 with different chain extenders and assessed rheology and biocompatibility of the resulting hydrogels. The best candidate was tested in a rat's femoral defect model. All gels hardened above 25 °C with butane-diisocyanate-hydrogels (BDI-gels) displaying the highest storage moduli. BDI-gels showed the most favourable biocompatibility and did not affect cellular adipogenic or osteogenic differentiation in vitro. Implantation of BDI-hydrogel into femoral defects did not impede bone healing in vivo as evidenced by μCT and histological analysis. We conclude that thermosensitive BDI-gels are promising alternative cell carriers. The gels harden upon injection in vivo without interfering with bone metabolism. Further experiments will assess the gels' capacity to effectively transport living cells into bone defects.
authors.affiliation: Experimental Surgery and Regenerative Medicine, Department of Surgery, Ludwig-Maximilians-University, Nussbaumstr. 20, 80336 Munich, Germany.
authors.forename: Elias
authors.initials: E
authors.lastname: Volkmer
authors.forename: Uta
authors.initials: U
authors.lastname: Leicht
authors.forename: Martina
authors.initials: M
authors.lastname: Moritz
authors.forename: Christina
authors.initials: C
authors.lastname: Schwarz
authors.forename: Hinrich
authors.initials: H
authors.lastname: Wiese
authors.forename: Stefan
authors.initials: S
authors.lastname: Milz
authors.forename: Philipp
authors.initials: P
authors.lastname: Matthias
authors.forename: Winfried
authors.initials: W
authors.lastname: Schloegl
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Friess
authors.forename: Michael
authors.initials: M
authors.lastname: Goettlinger
authors.forename: Peter
authors.initials: P
authors.lastname: Augat
authors.forename: Matthias
authors.initials: M
authors.lastname: Schieker
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D001831:Body Temperature; D020100:Hydrogels / Q000737:chemistry*; D066298:In Vitro Techniques; D020442:Poloxamer / Q000737:chemistry*; D051381:Rats; D012212:Rheology
chemical_list: D001672:Biocompatible Materials; D020100:Hydrogels; D020442:Poloxamer