Assessment of bone healing ability of calcium phosphate cements loaded with platelet lysate in rat calvarial defects

Abstract

Injectable calcium phosphate cements have been used as a valid alternative to autologous bone grafts for bone augmentation with the additional advantage of enabling minimally invasive implantation procedures and for perfectly fitting the tissue defect. Nevertheless, they have low biodegradability and lack adequate biochemical signaling to promote bone healing and remodeling. In previous in vitro studies, we observed that the incorporation of platelet lysate directly into the cement paste or loaded in hyaluronic acid microspheres allowed to modulate the cement degradation and the in vitro expression of osteogenic markers in seeded human adipose derived stem cells. The present study aimed at investigating the possible effect of this system in new bone formation when implanted in calvarial bilateral defects in rats. Different formulations were assessed, namely plain calcium phosphate cements, calcium phosphate cements loaded with human platelet lysate, hybrid injectable formulations composed of the calcium phosphate cement incorporating hyaluronin acid non-loaded microparticles (20% hyaluronin acid) or with particles loaded with platelet lysate. The degradability and new bone regrowth were evaluated in terms of mineral volume in the defect, measured by micro-computed tomography and histomorphometric analysis upon 4, 8 and 12 weeks of implantation. We observed that the incorporation of hyaluronin acid microspheres induced an overly rapid cement degradation, impairing the osteoconductive properties of the cement composites. Moreover, the incorporation of platelet lysate induced higher bone healing than the materials without platelet lysate, up to four weeks after surgery. Nevertheless, this effect was not found to be significant when compared to the one observed in the sham-treated group.

Injectable and tunable hyaluronic acid hydrogels releasing chemotactic and angiogenic growth factors for endodontic regeneration

“…Soft tissue defects must be reliably restored to their original shape and dimensions in addition to having physiological function. Swelling property of the hydrogels is crucial for substance exchange; however, an exceeding swelling behaviour can result in postoperative volume augmentation and displacement from the implantation site [58,59]. In endodontic regenerative therapies, this feature can increase the hydrostatic pressure inside the root canal system, thus breaking the tooth from contact areas between cement/resin and dentin/enamel or from existing clefts in the tooth.…”

Human periodontal ligament stem cells on calcium phosphate scaffold delivering platelet lysate to enhance bone regeneration

“…Previous studies 43,44 added HPL to hyaluronic acid microparticles and then mixed with CPC to form a system for HPL delivery for bone regeneration. However, the incorporation of hyaluronic acid microparticles reduced the mechanical properties of the CPC.…”

Calcium phosphate cements for bone engineering and their biological properties

“… 79 A recent study applied a commercially injectable CPC (Calcibon) with platelet lysates in bilateral calvarial defects in rats. 81 The delivery of the platelet lysate enhanced bone healing with an injectable CPC at early healing times. In large animal models, injectable CPCs have also shown promise for bone regeneration.…”