Acceleration of Bone Healing by In Situ-Forming Dextran-Tyramine Conjugates Containing Basic Fibroblast Growth Factor in Mice

Abstract

An enzymatic crosslinking strategy using hydrogen peroxide (H 2 O 2) and horseradish peroxidase (HRP) has been receiving increasing attention for use with in situ-formed hydrogels (IFHs). Several studies have reported the application of IFHs in cell delivery and tissue engineering. IFHs may also be ideal carrier materials for bone repair, although their potential as a carrier for basic fibroblast growth factor (bFGF) has yet to be evaluated. Here, we examined the effect of an IFH made of dextran (Dex)-tyramine (TA) conjugates (IFH-Dex-TA) containing bFGF in promoting bone formation in a fracture model in mice. Immediately following a fracture procedure, animals either received no treatment (control) or an injection of IFH-Dex-TA/phosphate-buffered saline (IFH-Dex-TA/PBS) or IFH-Dex-TA containing 1 μg bFGF (IFH-Dex-TA/bFGF) into the fracture site (n=10, each treatment). Fracture sites injected with IFH-Dex-TA/bFGF showed significantly greater bone volume, mineral content, and bone union than sites receiving no treatment or treated with IFH-Dex-TA/PBS alone (each n=10). This Dex-TA gel may be an effective drug delivery system for optimizing bFGF therapy.

Recent Advances of Pullulan and/or Dextran-Based Materials for Bone Tissue Engineering Strategies in Preclinical Studies: A Systematic Review

“…Ectopic bone formation was investigated in six studies using subcutaneous implantation in the back of animals or by muscular implantation (e.g., leg muscles) ( Table 2 ) ( Maire et al, 2005a ; Degat et al, 2009 ; Hayashi et al, 2009 ; Fricain et al, 2013 ; Chen et al, 2019 ; Yu et al, 2020 ). Orthotopic implantations were mainly performed on maxillofacial defects and long bone defects ( Tables 3 , 4 , 5 ) ( Lafont et al, 2004 ; Chen et al, 2005 ; Chen et al, 2006 ; Chen et al, 2007 ; Hayashi et al, 2009 ; Abbah et al, 2012 ; Fujioka-Kobayashi et al, 2012 ; Miyahara et al, 2012 ; Fricain et al, 2013 ; Bölgen et al, 2014 ; Schlaubitz et al, 2014 ; Takahata et al, 2015 ; Togami et al, 2015 ; Frasca et al, 2017 ; Ribot et al, 2017 ; Charoenlarp et al, 2018 ; Fricain et al, 2018 ; Ritz et al, 2018 ; Ding et al, 2019 ; Fang et al, 2019 ; Popescu et al, 2020 ; Shoji et al, 2020 ; Maurel et al, 2021 ; Wang et al, 2021 ). Nine studies investigated calvarial defects, six studies focused on mandibular or maxillary defects (e.g., periodontal, sinus bone augmentation), whereas 10 studies were performed on femoral defects (e.g., condyle, epiphysis, metaphysis), one study on ulnar defect and one study on tibial defect.…”

“…In most cases, when pullulan or dextran was used alone, chemical functionalization of the polysaccharide was performed to improve the cross-linking process and/or to promote their binding capacity to growth factors. For dextran derivatives, acrylate groups ( Chen et al, 2006 ; Chen et al, 2007 ) (e.g., glycidyl methacrylate, urethane methacrylate), amine or amide derivatives ( Lafont et al, 2004 ; Maire et al, 2005a ; Degat et al, 2009 ; Abbah et al, 2012 ; Shoji et al, 2020 ) (e.g., benzylamide, diethylaminoethyl, tyramine), carboxyl ( Lafont et al, 2004 ; Degat et al, 2009 ; Ritz et al, 2018 ) (e.g., carboxylate, carboxymethyl, formylbenzoic), aldehyde ( Wang et al, 2021 ), catechol ( Wang et al, 2021 ) (i.e., dopamine), or sulfated groups ( Chen et al, 2019 ) were added to the dextran backbone in 11 studies. Concerning pullulan derivatives, acrylate groups ( Hayashi et al, 2009 ; Fujioka-Kobayashi et al, 2012 ; Miyahara et al, 2012 ; Charoenlarp et al, 2018 ) (e.g., acryloyl, cholesteryl) or phosphate groups ( Takahata et al, 2015 ) were added for functionalization in five studies.…”

“…Chemical cross-linking was the most commonly used procedure. For chemically cross-linked dextran and/or pullulan-derived biomaterials, a wide range of reagents and reactions were employed, such as methylenebisacrylamide ( Bölgen et al, 2014 ) (MBAm), polyethylene glycol ( Chen et al, 2006 ) (PEG), thiol group-modified polyethylene glycol ( Hayashi et al, 2009 ; Fujioka-Kobayashi et al, 2012 ; Miyahara et al, 2012 ; Charoenlarp et al, 2018 ) (PEGSH), PEGSH with “arginine-glycine-aspartate” (RGD) peptides ( Charoenlarp et al, 2018 ), sodium trimetaphosphate ( Maire et al, 2005a ; Fricain et al, 2013 ; Schlaubitz et al, 2014 ; Frasca et al, 2017 ; Ribot et al, 2017 ; Fricain et al, 2018 ; Maurel et al, 2021 ) (STMP), through Schiff reaction (imine bonding) ( Wang et al, 2021 ), through enzymatic reaction ( Shoji et al, 2020 ) (e.g., hydrogen peroxide, horseradish peroxidase) or by activating a photocross-linking group using UV light ( Ritz et al, 2018 ).…”

“…Another reported strategy to enhance bone formation was the incorporation of bioactive molecules to these biomaterials to create a delivery system. Growth factors were employed in 13 studies, namely, bone morphogenetic proteins ( Chen et al, 2005 ; Maire et al, 2005a ; Chen et al, 2007 ; Degat et al, 2009 ; Hayashi et al, 2009 ; Abbah et al, 2012 ; Fujioka-Kobayashi et al, 2012 ; Charoenlarp et al, 2018 ; Chen et al, 2019 ; Yu et al, 2020 ) (e.g., BMP-2 and BMP-7), basic fibroblast growth factor ( Shoji et al, 2020 ) (bFGF), fibroblast growth factor ( Fujioka-Kobayashi et al, 2012 ; Charoenlarp et al, 2018 ) (FGF18), insulin-like growth factor ( Chen et al, 2006 ) (IGF-1) and stromal-derived growth factor ( Ritz et al, 2018 ) (SDF-1). One study reported the incorporation into the scaffold of bisphosphonate, which exhibits strong affinity with hydroxyapatite ( Wang et al, 2021 ).…”

“…Another reported strategy to enhance bone formation was the incorporation of bioactive molecules to these biomaterials to create a delivery system. Growth factors were employed in 13 studies, namely, bone morphogenetic proteins (Chen et al, 2005;Maire et al, 2005a;Chen et al, 2007;Degat et al, 2009;Hayashi et al, 2009;Abbah et al, 2012;Fujioka-Kobayashi et al, 2012;Charoenlarp et al, 2018;Chen et al, 2019;Yu et al, 2020) (e.g., BMP-2 and BMP-7), basic fibroblast growth factor (Shoji et al, 2020) (bFGF), fibroblast growth factor (Fujioka-Kobayashi et al, 2012;Charoenlarp et al, 2018) (FGF18), insulin-like growth factor (Chen et al, 2006) (IGF-1) and stromal-derived growth factor (Ritz et al, 2018) (SDF-1). One study reported the Osteoid tissue formation for both conditions BMC, bone mineral content; BMD, bone mineral density; BV/TV, bone volume over total volume; β-TCP, beta-tricalcium phosphate; H, height; HA, hydroxyapatite; L, length; MC, mineral content; MD, mineral density; Micro-CT, micro-computed tomography; MRI, magnetic resonance imaging; MSCs, mesenchymal stromal cells; MV/TV, mineral volume over total volume; NS, not specified; NaCl, sodium chloride; * p < 0.05; ** p < 0.01; ø, diameter.…”