<i>In Vivo</i> Estimation of Osteogenesis by Bone Marrow Cells in a Bi-Phasic Scaffold and in Each of Its Components

Abstract

A bi-phasic scaffold consisting of a columnar formaldehyde-acetalized polyvinyl alcohol (PVF) sponge and a cylindrical porous hydroxyapatite (HA) with a hollow center was devised. Rat bone marrow cells (rBMCs) were seeded into the sponge placed in the hollow center of the cylindrical porous HA. The bi-phasic scaffold, a cylindrical porous HA and a PVF sponge separated from a bi-phasic scaffold after rBMC seeding, and a PVF sponge without rBMCs as a negative control, were implanted for 6 weeks into rat dorsal subcutaneous tissue. In each construct, bone formation was examined histologically and osteocalcin was measured immunochemically. Bone formation was observed in the bi-phasic scaffold and also in the cylindrical porous HA isolated from the bi-phasic scaffold. A significant difference in the quantity of osteocalcin was observed between the bi-phasic scaffold and the isolated cylindrical porous HA. No bone formation was found in the isolated PVF sponge. The bi-phasic scaffold as an outer layer of the scaffold seemed to inhibit the outflow of rBMCs from the PVF sponge. This type of bi-phasic scaffold may have two specific characteristics: Attachment of cells both in PVF sponge and cylindrical porous HA.

Calcified Nodule Formation <i>in Vitro</i> Using Rat Mandibular Incisor Pulp Cells

“…In this study, calcified nodules were formed by cells from dental pulp. The appearance of the nodules was different from those formed by rBMCs in our previous reports [21][22][23]. Microscopically, the calcified nodules formed by rDPCs had lower levels of Ca 2+ deposition than the nodules by rBMCs.…”

“…Based on our in vitro preliminary experiments, the period for dental pulp cell culture until calcified nodule formation from the primary culture may be long. In the previous in vivo and in vitro studies by Yoshikawa et al [5] [21][22][23], bone marrow cells from the femur of rats were used to examination hard tissue formation as a substitute for cells obtained from dental pulp. The proliferation of stem cells in dental pulp cells was not evaluated and osteogenic potential of bone marrow cells was not compared with hard tissue forming ability by dental pulp-derived cells in this study.…”

Calcified nodule formation by dental pulp cells derived from rats after subcutaneous injection of an immunosuppressant

“…According to an in vitro study using rat bone marrow cells, the number of cells required for calcified nodule formation in subculture is 1 × 10 5 cells per well in a 6-well culture plate [19]. The number of bone marrow cells obtained from one rat femur was approximately 1.0 to 1.6 × 10 7 cells after primary culture in T-75 flasks for 7-10 days in most of our previous experiments [20,21,22]. In the oral cavity, MSCs are present in the dental pulp [23], periodontal ligament [24] and gingiva [25].…”

Hard Tissue-Forming Ability and Ultra-Micro Structure of Newly Developed Sponges as Scaffolds Made with Sodium Alginate Gel and Chondroitin Sulfate

“…Previously, in vivo experiments using formalin-treated polyvinyl alcohol (PVF) sponges were performed [65]. A PVF-HA complex as a scaffold was implanted subcutaneously.…”