A novel amorphous calcium phosphate polymer ceramic for bone repair: I. Synthesis and characterization

Abstract

Traditional materials for bone repair or replacements such as autografts and allografts have a limited supply and other complications. Thus, alternative materials need to be explored. Three-dimensional, porous composites prepared from bioresorbable polymers and hydroxyapatite or other calcium phosphate ceramics are promising materials for the repair or replacement of diseased or damaged bone. However, in many cases the ceramic component of these composites is crystalline in nature, while bone apatite is made of a poorly crystalline, carbonated phosphate system. In this study, we synthesized a noncrystalline, carbonated calcium phosphate ceramic by carrying out the reaction within bioresorbable PLAGA microspheres using a modified emulsion/solvent evaporation technique, making each individual microsphere a composite. Sintering the composite microspheres together yielded a bioresorbable, porous, 3-dimensional scaffold that may be ideal for tissue ingrowth, making this composite scaffold potentially suitable for bone repair applications.

Poly(lactide-co-glycolide)/hydroxyapatite composite scaffolds for bone tissue engineering

“…The SC/PL method causes the polymer coating on the bioceramics by polymer solutions, which hinders the exposure of bioceramics on the scaffold surfaces, while the GF/PL method, which does not use a polymer solution, efficiently exposes the bioceramics on the scaffold surface. Therefore, a GF/PL scaffold can increase the chances of osteogenic cells to make contact with the bioactive ceramics, which enhances osteoblast differentiation and growth [7][8][9].…”

“…Since the SC/PL and GF/PL scaffolds have similar physical properties such as porosity, pore size, and interconnectivity, the difference in osteogenic ability between the two scaffold types might be due to their different surface chemistries. Enhanced bone formation in vitro and in vivo on the GF/PL scaffolds may result from the direct contact of seeded cells with the HA particles exposed on the scaffold surface, which stimulate the cell proliferation and osteogenic differentiation [7,8]. In contrast, the HA particles would be coated with the polymer, which would hinder interaction with cells in the SC/PL scaffolds.…”

“…The interactions of osteogenic cells with bioceramics are important for bone regeneration [6]. Bioactive ceramics are known to enhance osteoblast differentiation as well as osteoblast growth [7,8]. Bioactive ceramics have been used in dental and orthopedic surgery to fill bone defects and to coat on metallic implant surfaces to improve implant integration with the host bone.…”

A poly(lactic acid)/calcium metaphosphate composite for bone tissue engineering

“…In the case of the conventional sintering method, solvent free process has favor to overcome this disadvantage [6]. Blending of polymer, ceramic and salt followed by pressing with heating, a conventional sintering method, can reduce the degree of coating compared to solvent casting method [14]. But there are still chances of coating of ceramics by polymer melting.…”

“…Bioactive ceramics such as hydroxyapatite, betatricalcium phosphate, and calcium metaphosphate (CMP) are known to provoke specific biological responses at the interface of the materials resulting in the formation of a strong bond between the tissue and materials [12]. Also, it has been proved that the bioceramics enhance osteoblast differentiation as well as osteoblast growth (osteoconductive property) [13][14][15][16][17].…”