maxresorb^® inject

The development of injectable bone regeneration materials started with the discovery of calcium cements in the 90’s [1]. Cements are produced by mixing calcium phosphate powder with an aqueous solution. Cements create the possibility for several minimal invasive therapies of bony defects and offer an easier handling in many indications. Following application, the hardening occurs in vivo.

Putties, like maxresorb^® inject, offer two significant advantages over cements: Firstly, their increased porosity allows for the ingrowth of blood vessels and bone tissue, resulting in a fast and complete integration into new bone matrix and a rapid natural remodeling; secondly, owing to their large surface area, the nano/micro HA particles exhibit a high biologic activity resulting in an osteostimulative effect. Nano/micro HA particles support the adhesion of bone cells, which promote a fast particle degradation, offering thus additional space for the ingrowth of new bone tissue.

Unlike other products, maxresorb® inject is not hardening in situ. Thus, the easy-to-handle paste-like structure of maxresorb® inject enables a very fast vascularization of the defect while providing an osteoconductive scaffold for the migration of bone forming cells. Hardening bone putties are often associated with low tissue integration due to the formation of a solid body that prevents cell and vessel penetration into the material.
Due to it’s non-hardening characteristics, maxresorb® inject always has to be covered with a barrier membrane to stabilize the material and facilitate undisturbed bony regeneration.

maxresorb® inject is predominantly composed of a nano-HA gel (83.5%). Due to the abundance of nano-HA particles within the material, and thereby their large surface area, the nano-HA particles promote cellular interactions that in turn results in accelerated new bone formation, as well as a fast cellular resorption of the particles. The embedded maxresorb® particles help to maintain the volume to a certain extent, but due to the relatively low content of maxresorb® particles within the paste, maxresorb® inject paste does not provide sufficient stability for predictable regeneration of larger defects. To increase stability, maxresorb® inject can be mixed with a slowly resorbable material such as cerabone® or maxresorb®.

Directly following application the water will dissolve leaving behind nano-HA particles and HA/beta-TCP granules. The nano-HA particles exhibit a high biologic activity because of their large surface, meaning a strong interaction with bone forming cells as well as macrophages and osteoclasts. The small particles are resorbed very fast (~6-8 weeks), but also promote fast new bone formation in the resulting free spaces. At the same time the beta-TCP/HA granules provide a scaffold for the migration of bone forming cells and the deposition of new bone matrix. Beta-TCP will resorb within ~3-6 months, HA within ~2-3 years.