Dataset Information

Vancomycin-bearing synthetic bone graft delivers rhBMP-2 and promotes healing of critical rat femoral segmental defects.

ABSTRACT:

Background

Bone grafts simultaneously delivering therapeutic proteins and antibiotics may be valuable in orthopaedic trauma care. Previously, we developed a poly(2-hydroxyethyl methacrylate)-nanocrystalline hydroxyapatite (pHEMA-nHA) synthetic bone graft that, when preabsorbed with 400-ng rhBMP-2/7, facilitated the functional repair of critical-size rat femoral defects. Recently, we showed that pHEMA-nHA effectively retains/releases vancomycin and rhBMP-2 in vitro. The success of such a strategy requires that the incorporation of vancomycin does not compromise the structural integrity of the graft nor its ability to promote bone healing.

Questions/purposes

(1) To evaluate the ability of pHEMA-nHA-vancomycin composites in combination with 3-µg rhBMP-2 to repair 5 mm rat femoral segmental defects, and (2) To determine if the encapsulated vancomycin impairs the graft/rhBMP-2-assisted bone repair.

Methods

pHEMA-nHA-vancomycin, pHEMA-nHA, or collagen sponge control with/without 3-µg rhBMP-2 were press-fit in 5 mm femoral defects in SASCO-SD male rats (289-300 g). Histology, microcomputed tomography, and torsion testing were performed on 8- and 12-week explants to evaluate the extent and quality of repair. The effect of vancomycin on the temporal absorption of endogenous BMP-2 and stromal cell-derived factor-1 was evaluated by immunohistochemistry. These factors are important for bone healing initiation and stem cell recruitment, respectively.

Results

Partial bridging of the defect with bony callus by 12 weeks was observed with pHEMA-nHA-vancomycin without rhBMP-2 while full bridging with substantially mineralized callus and partial restoration of torsional strength was achieved with 3-µg rhBMP-2. The presence of vancomycin changed the absorption patterns of endogenous proteins on the grafts, but did not appear to substantially compromise graft healing.

Conclusions

The composite pHEMA-nHA-vancomycin preabsorbed with 3-µg rhBMP-2 promoted repair of 5 mm rat femoral segmental defects. With the sample sizes applied, vancomycin encapsulation did not appear to have a negative effect on bone healing.

Clinical relevance

pHEMA-nHA-vancomycin preabsorbed with rhBMP-2 may be useful in the repair of critical-size long bone defects prone to infections.

SUBMITTER: Skelly JD

PROVIDER: S-EPMC4397773 | biostudies-literature | 2014 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Vancomycin-bearing synthetic bone graft delivers rhBMP-2 and promotes healing of critical rat femoral segmental defects.

Skelly Jordan D JD Lange Jeffrey J Filion Tera M TM Li Xinning X Ayers David C DC Song Jie J

Clinical orthopaedics and related research 20140807 12

<h4>Background</h4>Bone grafts simultaneously delivering therapeutic proteins and antibiotics may be valuable in orthopaedic trauma care. Previously, we developed a poly(2-hydroxyethyl methacrylate)-nanocrystalline hydroxyapatite (pHEMA-nHA) synthetic bone graft that, when preabsorbed with 400-ng rhBMP-2/7, facilitated the functional repair of critical-size rat femoral defects. Recently, we showed that pHEMA-nHA effectively retains/releases vancomycin and rhBMP-2 in vitro. The success of such a ...[more]

PMID: 25099263

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Dataset Information

Vancomycin-bearing synthetic bone graft delivers rhBMP-2 and promotes healing of critical rat femoral segmental defects.

Background

Questions/purposes

Methods

Results

Conclusions

Clinical relevance

Publications

Vancomycin-bearing synthetic bone graft delivers rhBMP-2 and promotes healing of critical rat femoral segmental defects.

Similar Datasets

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