RHBMP-2 RELEASE FROM INJECTABLE POLY(DL-LACTIC-CO-GLYCOLIC ACID)/CALCIUM-PHOSPHATE CEMENT COMPOSITES

The release kinetics of recombinant human bone morphogenetic protein-2 (rhBMP-2) loaded poly(DL-lactic-co-glycolic acid)/calcium phosphate cement (PLGA/Ca-P cement) composites were studied in vivo. RhBMP-2 was radiolabeled with 131I and entrapped within PLGA microparticles or adsorbed onto the microparticle surface. PLGA microparticles were prepared of high molecular weight (HMW) PLGA (weight average molecular weight [Mw] 49,100 ± 1,700) or low molecular weight (LMW) PLGA (Mw 5,900 ± 300) and used for preparation of 30:70 wt% PLGA/Ca-P cement composite discs. Release of 131I-rhBMP-2 loaded composites was assessed by scintigraphic imaging according to a 22 two-level full factorial design in the rat ectopic model during four weeks. In vivo release kinetics varied among formulations. All formulations showed slow release without initial burst, and displayed a linear release from 3 to 28 days. Release of LMW entrapped rhBMP-2 composites (1.7 ± 0.3%/day) was significantly faster than release from other formulations (p < 0.01). After 28 days, retention within the composites was 65 ± 5%, 75 ± 4%, 50 ± 4% and 70 ± 6% of the initial rhBMP-2 for HMW entrapped, HMW adsorbed, LMW entrapped and LMW adsorbed rhBMP-2 composites, respectively. Release from the composite was probably slowed down by an interaction of rhBMP-2 and Ca-P cement after rhBMP-2 release from PLGA microparticles. We conclude that PLGA/Ca-P cement composites can be considered as sustained slow release vehicles and that the release and retention of rhBMP-2 can be modified according to the desired profile to a limited extent.

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Mechanical and rheological properties and injectability of calcium phosphate cement containing poly (lactic-co-glycolic acid) microspheres

Materials Science and Engineering C ◽

10.1016/j.msec.2009.02.021 ◽

2009 ◽

Vol 29 (6) ◽

pp. 1901-1906 ◽

Cited By ~ 17

Author(s):

Xiaopeng Qi ◽

Jiandong Ye

Keyword(s):

Calcium Phosphate ◽

Rheological Properties ◽

Calcium Phosphate Cement ◽

Glycolic Acid

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Polymer-calcium phosphate cement composites for bone substitutes

Journal of Biomedical Materials Research ◽

10.1002/jbm.10222 ◽

2002 ◽

Vol 61 (4) ◽

pp. 581-592 ◽

Cited By ~ 64

Author(s):

Rafal A. Mickiewicz ◽

Anne M. Mayes ◽

David Knaack

Keyword(s):

Calcium Phosphate ◽

Calcium Phosphate Cement ◽

Bone Substitutes ◽

Cement Composites

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Effect of Polymer Molecular Weight on the Bone Biological Activity of Biodegradable Polymer/Calcium Phosphate Cement Composites

Tissue Engineering Part A ◽

10.1089/ten.tea.2008.0694 ◽

2009 ◽

Vol 15 (10) ◽

pp. 3183-3191 ◽

Cited By ~ 37

Author(s):

Esther W.H. Bodde ◽

Wouter J.E.M. Habraken ◽

Antonios G. Mikos ◽

Paul H.M. Spauwen ◽

John A. Jansen

Keyword(s):

Molecular Weight ◽

Biological Activity ◽

Calcium Phosphate ◽

Calcium Phosphate Cement ◽

Biodegradable Polymer ◽

Cement Composites ◽

Polymer Molecular Weight

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Polymeric-Calcium Phosphate Cement Composites-Material Properties:In VitroandIn VivoInvestigations

International Journal of Biomaterials ◽

10.1155/2010/691452 ◽

2010 ◽

Vol 2010 ◽

pp. 1-14 ◽

Cited By ~ 16

Author(s):

Rania M. Khashaba ◽

Mervet M. Moussa ◽

Donald J. Mettenburg ◽

Frederick A. Rueggeberg ◽

Norman B. Chutkan ◽

...

Keyword(s):

Calcium Phosphate ◽

Calcium Phosphate Cement ◽

Setting Time ◽

Cement Composites ◽

Tetracalcium Phosphate ◽

Methyl Vinyl Ether ◽

Orthopedic Applications ◽

Hydroxyapatite Cement

New polymeric calcium phosphate cement composites (CPCs) were developed. Cement powder consisting of 60 wt% tetracalcium phosphate, 30 wt% dicalcium phosphate dihydrate, and 10 wt% tricalcium phosphate was combined with either 35% w/w poly methyl vinyl ether maleic acid or polyacrylic acid to obtain CPC-1 and CPC-2. The setting time and compressive and diametral tensile strength of the CPCs were evaluated and compared with that of a commercial hydroxyapatite cement.In vitrocytotoxicity andin vivobiocompatibility of the two CPCs and hydroxyapatite cement were assessed. The setting time of the cements was 5–15 min. CPC-1 and CPC-2 showed significantly higher compressive and diametral strength values compared to hydroxyapatite cement. CPC-1 and CPC-2 were equivalent to Teflon controls after 1 week. CPC-1, CPC-2, and hydroxyapatite cement elicited a moderate to intense inflammatory reaction at 7 days which decreased over time. CPC-1 and CPC-2 show promise for orthopedic applications.

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