Hydroxyapatite/polyurethane scaffold incorporated with drug‐loaded ethyl cellulose microspheres for bone regeneration

Abstract

The purpose of this study is to explore and develop biodegradable scaffold for bone regeneration or tissue engineering with the capacity of controlled drug delivery. Ceftazidime as a model drug was encapsulated in ethyl cellulose (EC) microspheres, which were subsequently incorporated in a hydroxyapatite/polyurethane (HA/PU) composite scaffold to generate an antibiotic drug delivery system. HA/PU scaffolds had an interconnected pore network with an average porosity of about 83%. The presence of microspheres in the composite scaffolds was confirmed by scanning electron microscopy. The drug-loaded EC microspheres were uniformly distributed in the HA/PU scaffold matrix and showed no significant effect on the pore structure of the scaffold. Incorporation of microspheres into scaffolds significantly reduced the initial burst release, and the system exhibited a sustained release of the model drug for up to 60 days. Moreover, the scaffold with drug-loaded microspheres was proved to be an effective drug delivery system with good cytocompatibility and antibacterial properties. The novel drug-loaded microsphere/scaffold composites developed in this study are promising to serve as vehicles for controlled drug delivery in bone regeneration or bone tissue engineering.

Fabrication and characterization of drug-loaded nano-hydroxyapatite/polyamide 66 scaffolds modified with carbon nanotubes and silk fibroin

“…41 Drug-eluting stents loaded with growth factors or antiinflammatory drugs can promote bone tissue repair or treat an infection. [42][43][44][45] Our research is the first to fabricate the drugloaded nHA/PA66 conjugated CNTs scaffold. The CNTs improved the mechanical and conductive properties of nHA/ PA66 scaffold.…”

Synthesis and structure-property relationships of biodegradable polyurethanes

“…Also, the ability to produce BioPUs as foams or elastomers grants additional degrees of freedom in the design of products with desired properties [178]. Drug delivery systems based on BioPUs can be in the form of nano-or microparticulate systems [179] such as micelles [180][181][182] nanoparticles [183,184], nanocapsules [185][186][187], microspheres [188,189] and pellets [190], as well as membrane systems [191][192][193][194][195].…”

Recent advances in materials for extended-release antibiotic delivery system

“…Besides, incorporation of microspheres into scaffolds can abolish the initial burst by a combination of pore diffusion and polymer erosion. 33,34 Bioadhesive materials The objective of using mucoadhesive or bioadhesive controlled drug delivery system is to prolong their residence at a specific site of delivery, thus facilitating the drug absorption process. For mucoadhesive agent, first-pass metabolism in the liver and presystemic elimination in the GI tract is avoided as the mucosa is well supplied with both vascular and lymphatic drainage.…”