Development of porous HAp and β-TCP scaffolds by starch consolidation with foaming method and drug-chitosan bilayered scaffold based drug delivery system

Abstract

The inability to maintain high concentrations of antibiotic at the site of infection for an extended period of time along with dead space management is still the driving challenge in treatment of osteomyelitis. Porous bioactive ceramics such as hydroxyapatite (HAp) and beta-tri calcium phosphate (β-TCP) were some of the alternatives to be used as local drug delivery system. However, high porosity and high interconnectivity of pores in the scaffolds play a pivotal role in the drug release and bone resorption. Ceftriaxone is a cephalosporin that has lost its clinical popularity. But has recently been reported to exhibit better bactericidal activity in vitro and reduced probability of resistance development, in combination with sulbactam, a β-lactamase inhibitor. In this article, a novel approach of forming HAp and pure β-TCP based porous scaffolds by applying together starch consolidation with foaming method was used. For the purpose, pure HAp and β-TCP were prepared in the laboratory and after thorough characterization (including XRD, FTIR, particle size distribution, etc.) the powders were used for scaffold fabrication. The ability of these scaffolds to release drugs suitably for osteomyelitis was studied in vitro. The results of the study indicated that HAp exhibited better drug release profile than β-TCP when drug was used alone indicating the high influence of the carrier material. However, this restriction got relaxed when a bilayered scaffold was formed using chitosan along with the drug. SEM studies along with EDAX on the drug-chitosan bilayered scaffold showed closest apposition of this combination to the calcium phosphate surface.

Effect of preparation conditions on the nanostructure of hydroxyapatite and brushite phases

“…Several researchers under different preparation conditions studied the synthesis of calcium phosphate extensively (Nilsson et al 2002;Ren et al 2012;Kundu et al 2010a). By varying temperature, pH and initial reagent concentrations, one can obtain different calcium phosphate phases (Kundu et al 2010b).…”

Bioceramic Scaffolds

“…A bilayered coating was also applied to the pore surfaces of some samples using chitosan and b-lactamase-cephalosporin derivative to assess their effect on sustained drug releasing. The result of bilayered coating of chitosan with CFS provided prolonged release pattern for more than 5 weeks irrespective of the scaffold material, a period that is considered to be sufficient for local drug delivery to combat osteomyelitis [136].…”

Development of bioactive glass based scaffolds for controlled antibiotic release in bone tissue engineering via biodegradable polymer layered coating

“…2,[9][10][11][12][13][14] Scaffolds are usually made from tailored combination of inorganic and organic phases, forming composite structures aiming to replicate the structure and composition of bone tissue. 2,3,13,15 Several bioactive glasses and bioceramics have been used as the inorganic phase in drug eluting composite scaffolds, including hydroxyapatite (HA), 6,7,16 calcium phosphate (CaP), [17][18][19] and Bioglass V R . [20][21][22][23] Scaffolds composed of a single inorganic component usually have low drug binding affinity, and thus, they do not allow a controlled drug release.…”

“…13 This is particularly the case for bioactive glass scaffolds derived from molten glasses, [20][21][22][23] which do not have a suitable intrinsic mesoporosity to be used as drug reservoirs. 3,10 Therefore, several natural-and synthetic-derived biodegradable polymers have been explored as the organic component for development of composite scaffolds, such as collagen, [24][25][26] gelatin, [27][28][29] chitosan, 2,18,19,30 alginate, [29][30][31] and polyesters. 16,[32][33][34][35] As early reported by Yaylao glu et al, 17 CaP/gelatin composite scaffolds have been loaded with gentamicin for in-situ drug delivery enhanced bone tissue engineering.…”