Abstract: Current tissue engineering strategies involve the use of scaffold materials with properties specific for the target tissue. When the tissue being treated is bone, properties such as bone bonding behaviour and excellent biological performance are very desirable. Many strategies involve the creation in vitro of a suitable hybrid construct (i.e., comprising a scaffold material and cells). These
scaffolds are then inserted into the defect site, thus achieving faster integration and hence, repair. Herein, we describe the synthesis and characterization of starch-based microparticles for bone tissue engineering. This study describes the properties of two types of starch-based microparticles: their
bioactivity in vitro (when processed with Bioactive Glass 45S5), the good biological performance and also the ability to be used as controlled release vehicles of bioactive molecules, such as steroids and growth factors.
Abstract: Porous hydroxyapatite coated with MCM-41/PCL has been utilized as the matrix for
controlled drug delivery. SEM result shows porous hydroxyapatite block is formed of three dimensionally inter-connected pores of 250 –300 *m in size, similar to human cancellous bone. TEM observation confirms the pore size of MCM-41 scatters about 50 Å. Ibuprofen was loaded into the pores of MCM-41 and hybridized with polycaprolactone to coat on the surface of hydroxyapatite block and controlled release profiles were studied by soaking the samples in a simulated body fluid using a UV-VIS spectrophotometer.
Abstract: In this paper, three different scale HA/PDLLA porous scaffolds, nano-HA/PDLLA,
micro-HA/PDLLA and pure PDLLA were successfully fabricated using solvent casting/particulate leaching method. Chondrocytes adhesion and proliferation on these scaffolds were investigated. In detail, the cells attachment rate and proliferation on nano-HA/PDLLA, micro-HA/PDLLA and pure
PDLLA were quantitatively evaluated by cytometry. The interaction between the scaffolds and chondrocytes were observed by optical microscope with HE staining and FE-SEM. The results exhibited that nano-HA/PDLLA scaffold has a modified cell adhesion property, and cells on the nano-scaffold grow much better both in biological and morphological characteristics than on the micro-HA/PDLLA and pure PDLLA scaffolds. This work suggested that nano-HA/PDLLA
composite scaffold can significantly improved cell adhesion and proliferation tendency with the existing of nano-effects，and could be used as a potential scaffold material for bone defect repair.
Abstract: The objective of this study was to evaluate cell adhesion and proliferation on the hydroxyapatite (HAp)-coated silk fibroin (SF) fabric. Nano-scaled sintered HAp particles were covalently coated on SF chemically modified by graft polymerization. After the fabrication of the HAp/SF composite,
mesenchymal cells (MCs) derived from EGFP-expressing transgenic rat bone marrow were seeded on the composite and cultured for 10 days. Fluorescence and scanning electron microscopy (SEM) revealed that the cells adhered and actively proliferated on the composites comparable to those on tissue culture polystyrene (TCPS) dishes. The results suggest that the composites are suitable for
mesenchymal cell culture scaffolds and useful materials for regenerative medicine.
Abstract: In this study, it is shown that it is possible to develop 3D-porous bilayer
hydroxyapatite/chitosan scaffolds by means of combining a sintering and a freeze-drying technique. Scanning electron microscopy (SEM/EDS) studies revealed that the scaffolds possess a well-defined orientation and anisotropic porosity, with pore size ranging between 50-350 µm. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) patterns evidenced the formation of
crystalline hydroxyapatite. Moreover, the compression tests revealed that these scaffolds have adequate mechanical properties for being used in tissue engineering of osteochondral defects.
Abstract: Bone morphogenetic protein (BMP) is known as a protein that induces new bone in heterotopic sites. This study was conducted to assess the cell-biological effects of crude porcine BMP and 3 pulp-capping materials by implantation and cell culture methods. The following results were obtained: a new bone site of approx 5mm in diameter were induced in the hind limbs, which confirmed the osteoinductive activity of the crude BMP. The pulp-capping materials hardly influenced the calcification of rat dental pulp (RDP) cells. Our data also suggest that the effect of
the crude BMP on the proliferation and calcification depended on its quantity. The finding of a large increase in the ALPase activity and the formation of mineralized nodules caused by the crude BMP , suggests that the crude BMP enhanced the calcification by RDP cells. Consequently, it is quite possible that crude porcine BMP could be used as a pulp-capping material.
Abstract: Porous apatite carrier with high selectivity of adsorption was prepared by using
hydrothermal method. α-TCP as the starting material was changed into hydroxyapatite at the temperature above 120 °C for the period over 3 h under saturated vapor pressure. Porous apatite carriers were composed of rod-shaped crystals with non-stoichiometric hydroxyapatite composition.
Since HA crystals had rod like shape, the area of a-surface was larger than that of c-surface. This carrier had higher selectivity for bovine serum albumin (acidic protein) than lysozyme chloride (basic protein). This material must be suitable as scaffold for cultured bone, for bone graft material and for drug delivery system (DDS).
Abstract: The preparation of hyperstructured hydroxyapatite (HAp) ceramics is reported.
Mesoporous silica with nano size pore was coated on the bi-modal type porous HAp ceramics with pore size 100-200 µm and 1-2 µm. The mesoporous silica coating was done using two different procedures and the ceramics were characterized by XRD, N2 Sorption, SEM/EDX, and TEM. The results clearly showed the formation of mesoporous coating on the large pores of parent HAp ceramics. SEM images reveal that the mesoporous coatings consists of almost spherical particles with
relatively uniform sizes of ~1 µm. Protein adsorption and release behavior on these mesoporous coated HAp ceramics was evaluated using UV-VIS spectrometry. The large pores are suitable for cell immobilization, and the mesopores several nm in size were found to enhance protein encapsulation ability.