Size effect of calcium phosphate coated with poly‐DL‐lactide‐ co‐glycolide on healing processes in bone reconstruction

Abstract

In this article, synthesis and application of calcium phosphate/poly-DL-lactide-co-glycolide (CP/PLGA) composite biomaterial in particulate form, in which each CP granule/particle is coated with PLGA, are described. Two types of the particulate material having different particle sizes were synthesized: one with an average particle diameter between 150 and 250 mum (micron-sized particles, MPs) and the other with an average particle diameter smaller than 50 nm (nanoparticles, NPs). A comparative in vivo analysis was done by reconstructing defects in osteoporotic alveolar bones using both composites. The material, CP granules/particles covered with polymer, was characterized using X-ray structural analysis, scanning electron microscopy, and atomic force microscopy. Changes in reparatory functions of tissues affected by osteoporosis were examined in mice in vivo, using these two kinds of composite materials, with and without autologous plasma. Having defined the target segment, histomorphometric parameters-bone area fraction, area, and mean density-were determined. The best results in the regeneration and recuperation of alveolar bone damaged by osteoporosis were achieved with the implantation of a mixture of nanoparticulate CP/PLGA composite and autologous plasma. After the implantation of microparticulate CP/PLGA, in the form of granules, mixed with autologous plasma, into an artificial defect in alveolar bone, new bone formation was also observed, although its formation rate was slower.

Multifunctional hydroxyapatite and poly(d,l-lactide-co-glycolide) nanoparticles for the local delivery of cholecalciferol

“…An interest in the applications of nanoparticles of calcium phosphates as carriers in targeted and controlled drug delivery and tissue engineering is rapidly growing [8]. HAp nanoparticles have so far been used as carriers for different pharmaceutically active components in controlled drug and gene delivery [9,10]. At the same time, a significant improvement of the processes of bone defect reconstruction has been achieved owing to the use of nanoparticulate systems based on HAp [9].…”

Nanosized hydroxyapatite and other calcium phosphates: Chemistry of formation and application as drug and gene delivery agents

“…As expected, smaller, nanosized particles are associated with significantly higher resorption rates compared with the bigger, microsized ones. 116 In addition to composition and size, the particle shape is also known to influence the uptake efficiency of the encapsulated drug. 117 The morphology of CAP particles may be thus used as a parameter in optimizing a favorable bioresorbability thereof.…”

Effects of Calcium Phosphate/Chitosan Composite on Bone Healing in Rats: Calcium Phosphate Induces Osteon Formation

“…The actual rate could be lower because the concentration of calcium and phosphate ions in the body fluid is likely higher than the minimal level 4.8 · 10 -5 FIG. 10. Histological (H&E stained) images of decalcified CaP-implanted defect tissue samples retrieved at day 60 postimplantation.…”

“…Numerous growth factors (notably bone morphogenetic proteins; BMPs) and biomaterials such as those containing CaP display an ability to stimulate osteoinduction. 9 The reported osteoinductivity of CaP is influenced by a number of physicochemical properties of the biomaterial, such as particle size, 10 surface area, crystallinity, porosity, and composition. 11,12 Particles of sizes ranging from 80 to 300 mm in diameter can induce ectopic bone formation, whereas particles greater than 500 mm are not osteoinductive.…”