title: Surface modification of PCL-TCP scaffolds improve interfacial mechanical interlock and enhance early bone formation: an in vitro and in vivo characterization.
abstract: Pretreatment of polycaprolactone-20% tricalcium phosphate (PCL-TCP) scaffolds under alkaline conditions can be utilized to alter surface characteristics for enhanced early bone formation. PCL-TCP scaffolds were treated with sodium hydroxide (NaOH) at various time intervals (group A: untreated, group B: 3M NaOH for 48 h, and group C: 3M NaOH for 96 h). In vitro results showed a greater degree of physical changes in the NaOH-treated scaffolds (B and C) than the untreated group (A). Clearly, the NaOH-treated scaffolds showed an increased surface roughness than the untreated ones. A significantly large number of "channel-like" pits and greater average pit sizes were detected in groups B (14.51 +/- 10.9 microm) and C (20.27 +/- 14.3 microm); and absent in group A. In addition, treated scaffolds had a significant reduction of the water contact angle (40.9-58.2%). Favorably, the pore dimensions and scaffold rod thickness remained unchanged throughout the experiment. When implanted in the calvaria of rabbits, NaOH-treated scaffolds reported greater early matrix deposition and bone formation from scanning electron images and Micro-computed tomography analyses. In conclusion, pretreatment of PCL-TCP scaffolds with NaOH increases the wettability and surface area for initial matrix deposition and early bone ingrowth.
authors.affiliation: Department of Restorative Dentistry, National Dental Centre, SingHealth, Singapore.
authors.forename: A
authors.initials: A
authors.lastname: Yeo
authors.forename: W J
authors.initials: WJ
authors.lastname: Wong
authors.forename: H H
authors.initials: HH
authors.lastname: Khoo
authors.forename: S H
authors.initials: SH
authors.lastname: Teoh
mesh_terms: D000818:Animals; D002130:Calcium Phosphates / Q000494:pharmacology*; D020007:Implants, Experimental; D008297:Male; D008422:Materials Testing; D055595:Mechanical Phenomena / Q000187:drug effects*; D008855:Microscopy, Electron, Scanning; D010012:Osteogenesis / Q000187:drug effects*; D011091:Polyesters / Q000494:pharmacology*; D016062:Porosity / Q000187:drug effects; D011817:Rabbits; D012886:Skull / Q000000981:diagnostic imaging / Q000187:drug effects / Q000473:pathology / Q000648:ultrastructure; D012972:Sodium Hydroxide / Q000494:pharmacology; D013499:Surface Properties / Q000187:drug effects; D054457:Tissue Scaffolds / Q000737:chemistry*; D014867:Water / Q000737:chemistry; D055114:X-Ray Microtomography
chemical_list: D002130:Calcium Phosphates; D011091:Polyesters; D014867:Water; C016240:polycaprolactone; D012972:Sodium Hydroxide; C018392:tricalcium phosphate