Osteopontin functionalization of hydroxyapatite nanoparticles in a PDLLA matrix promotes bone formation

Abstract

We studied the osteoconductive tissue response of hydroxyapatite (HA) nanoparticles functionalized with osteopontin (OPN) in a matrix of poly-d,l-lactic-acid (PDLLA). In a canine endosseus 0.75-mm gap implant model, we tested the osteointegrative impact of the OPN functionalized composite as an implant coating, and a non-functionalized composite was used as reference control. During the four weeks of observation, the OPN functionalized composite coating significantly increased the formation of new bone in the porosities of the implant, but no differences were observed in the gap. The study provides evidence of its potential use either alone or in combination with other osteoconductive compounds.

Enhancing regenerative approaches with nanoparticles

“…In addition to GFs, other proteins can be incorporated into biomaterials in order to stimulate bone tissue regeneration. For example, the extracellular matrix molecule osteopontin, a protein that plays an important role in bone remodelling, was incorporated in HA nanoparticles and its release from a degradable matrix was analysed for its osteoinductive potential in a dog bone defect model [61]. The majority of the developed nanocomposite materials for bone tissue engineering consider only the release of a single GF or biomolecule.…”

Integrating Mechanical and Biological Control of Cell Proliferation Through Bioinspired Multieffector Materials

“…Increased the formation of new bone in the porosities of a canine implant (151) TGF- Cyclodextrin(CD)-and Cucurbituril(CB)-based hydrogels Effective chondrogenic differentiation (115) VEGF PEG-based hydrogels Stimulates cell migration and proliferation and maintain cell viability (116,117) VEGF Embedded in gelatine-like gels…”

Nanoparticles and their potential for application in bone

“…9,10 The following paragraph focuses on the use of nanoparticles as an effective protein or drug delivery system to support bone tissue regeneration. For this purpose, several nondegradable particles, such as silica, lipid, dendrimer, hydroxyapatite, or gold nanoparticles, [43][44][45][46][47][48][49][50] as well as degradable particles made of poly(L-lactide) 51,52 or poly(L-lactideco-glycolide) (PLGA), 11,42,[52][53][54][55][56] have been used. Frequently, nanoparticles were combined with scaffolds such as proteinaceous hydrogels or degradable polymeric matrixes to facilitate application in bone.…”

“…Frequently, nanoparticles were combined with scaffolds such as proteinaceous hydrogels or degradable polymeric matrixes to facilitate application in bone. 47,48,53,55,56 As bone contains bone-forming cells, the osteoblasts, and bone-resorbing cells, the osteoclasts, which act in concert to guarantee bone homeostasis, 57,58 different strategies can be envisioned that could promote the regeneration of bone tissue. On the one hand, osteoblasts could be supported by nanoparticle-based growth factor delivery.…”

“…However, other than new bone formation within the matrix, no positive effects were observed in the gap itself. 47 In contrast to naturally occurring proteins, medium supplements for osteogenic differentiation in vitro, such as the synthetic glucocorticoid dexamethasone, are known to feature osteoinductive properties. 63 Accordingly, dexamethasoneloaded dendrimer nanoparticles in a scaffold supported the osteogenic differentiation of rat MSCs in vitro, like free dexamethasone.…”