Large 3D porous scaffolds made of active hydroxyapatite obtained by biomorphic transformation of natural structures and process for obtaining them

Inventors

Tampieri, Anna • Sprio, Simone • Ruffini, Andrea

Assignees

Greenbone Ortho Srl • Consiglio Nazionale delle Richerche CNR

Abstract

The present disclosure relates to a hydroxyapatite obtained from porous wood, having high compressive strength and dimensions suitable for clinical applications. The porous wood has a porosity of between about 60% and about 95%, said porosity being measured after subjecting the wood to a step of pyrolysis, and is selected from among rattan, pine, abachi, balsa, sipo, oak, rosewood, kempas and walnut wood. The hydroxyapatite may be substituted with one or more ions such as magnesium, strontium, silicon, titanium, carbonate, potassium, sodium, silver, gallium, copper, iron, zinc, manganese, europium, gadolinium. Also disclosed is a bone substitute comprising hydroxyapatite obtained from porous wood. The bone substitute is utilized for the substitution and regeneration of a bone or a bone portion, preferably for bones subjected to mechanical loads, such as long bones of the leg and arm, preferably the tibia, fibula, femur, humerus and radius. The invention relates also to a process for manufacturing a biomorphic hydroxyapatite scaffold from wood.

Core Innovation

The invention describes a process for producing a biomorphic hydroxyapatite scaffold by converting a native wood template into successive inorganic templates and then into hydroxyapatite. The process begins with pyrolysis of native wood heated under an inert atmosphere to yield a carbon template, which preserves a biomorphic pore architecture derived from the wood.

The carbon template is then infiltrated with calcium in the vapour state under specified temperature and pressure conditions to yield a calcium carbide template, followed by oxidation in air to yield a calcium oxide template. The calcium oxide template is exposed to water to enable water uptake in an amount of 125 mole %, thereby enabling subsequent template transformation during the next steps.

Next, the calcium oxide-derived template is transformed into calcium carbonate by heating under specified temperature and pressure conditions, and the calcium carbonate template is treated with at least one phosphate salt to yield the biomorphic hydroxyapatite scaffold. The disclosed approach emphasizes scale-relevant scaffold formation from native wood templates and formation of a biomorphic hydroxyapatite with hierarchically organized, anisotropic macro/micro/nano pore structure.

Claims Coverage

The document provides one independent claim directed to a sequential process for producing a biomorphic hydroxyapatite scaffold from native wood, comprising six named process steps. No additional independent claims are explicitly provided in the provided claim excerpt.

Claim coverage centers on the sequential template-conversion workflow from native wood to hydroxyapatite, defined by the ordered step sequence pyrolysis, vapour-state calcium carburization, oxidation, hydration with 125 mole % water uptake, carbonation, and phosphatization with phosphate salts.

Stated Advantages

Documented Applications