A 5–7 year in vivo study of high-strength hydroxyapatite/poly(l-lactide) composite rods for the internal fixation of bone fractures

Hasegawa, Shin; Ishii, Shinji; Tamura, Jiro; Furukawa, Taizo; Neo, Masashi; Matsusue, Yoshitaka; Shikinami, Yasuo; Okuno, Masaki; Nakamura, Takashi

doi:10.1016/j.biomaterials.2005.09.003

Cited by 112 publications

(80 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In vivo, the collagen/HA ratio appeared to be slightly higher near the transverse process than in the central part of the intertransverse process. 610 Hasegawa et al 1170 performed an in vivo study, spanning a period of 5-7 y, on high-strength HA/PLLA biocomposite rods for the internal fixation of bone fractures. In that work, both uncalcined CDHA and calcined HA were used as reinforcing phases in a PLLA matrix.…”

Section: Discussionmentioning

confidence: 99%

Biocomposites and hybrid biomaterials based on calcium orthophosphates

Dorozhkin¹

2011

Biomatter

152

View full text Add to dashboard Cite

show abstract

Section: Discussionmentioning

confidence: 99%

Biocomposites and hybrid biomaterials based on calcium orthophosphates

Dorozhkin¹

2011

Biomatter

152

View full text Add to dashboard Cite

show abstract

“…However, since bridging between the ceramic particles and host bone was dependent upon the degradation of poly-l-lactide (PLLA), 55 the rate of remodeling was slow, as evidenced by the fact that 4% of the composite implanted in rabbit femora remained after 7 years. 56 Further, the resorption zone near the host bone interface resulting from phagocytosis of the implant by histocytes 56 is anticipated to reduce its strength. Compression-molded ABP/PUR BCs incorporating 68 vol% ABP exhibited compressive strengths ranging from 100 to 170 MPa and supported extensive cellular infiltration at 6 weeks in rabbit femoral condyle defects.…”

mentioning

confidence: 99%

“…26 Settable weight-bearing bone grafts could potentially transform the management of tibial plateau fractures, screw augmentation, vertebroplasty, and other orthopedic indications, but their success is predicated on their ability to maintain sufficient bone-like strength actively remodeling. Weight-bearing composites generally comprise a resorbable reinforcing matrix (e.g., short fibers 20,21 or particles 22,56 ) dispersed in a continuous phase (e.g., polymers or ceramics). A recent review highlighting the challenges associated with the design of weight-bearing composites has suggested that the rates of degradation of the reinforcing matrix and the continuous phase should be matched to ensure adequate healing.…”

mentioning

confidence: 99%

Balancing the Rates of New Bone Formation and Polymer Degradation Enhances Healing of Weight-Bearing Allograft/Polyurethane Composites in Rabbit Femoral Defects

Dumas

Prieto

Zienkiewicz

et al. 2014

Tissue Engineering Part A

View full text Add to dashboard Cite

There is a compelling clinical need for bone grafts with initial bone-like mechanical properties that actively remodel for repair of weight-bearing bone defects, such as fractures of the tibial plateau and vertebrae. However, there is a paucity of studies investigating remodeling of weight-bearing bone grafts in preclinical models, and consequently there is limited understanding of the mechanisms by which these grafts remodel in vivo. In this study, we investigated the effects of the rates of new bone formation, matrix resorption, and polymer degradation on healing of settable weight-bearing polyurethane/allograft composites in a rabbit femoral condyle defect model. The grafts induced progressive healing in vivo, as evidenced by an increase in new bone formation, as well as a decrease in residual allograft and polymer from 6 to 12 weeks. However, the mismatch between the rates of autocatalytic polymer degradation and zero-order (independent of time) new bone formation resulted in incomplete healing in the interior of the composite. Augmentation of the grafts with recombinant human bone morphogenetic protein-2 not only increased the rate of new bone formation, but also altered the degradation mechanism of the polymer to approximate a zero-order process. The consequent matching of the rates of new bone formation and polymer degradation resulted in more extensive healing at later time points in all regions of the graft. These observations underscore the importance of balancing the rates of new bone formation and degradation to promote healing of settable weight-bearing bone grafts that maintain bone-like strength, while actively remodeling.

show abstract

“…Indeed, researchers are realizing that the extraordinary characteristics of nanophase ceramics (including size, structural advantages, highly active surfaces, unique physical and chemical properties, and ease of modification) imply that they can be excellent platforms for the drug transportation and controlled prolonged release compared with polymeric platforms. [1] Calcium phosphate (CAP) owing to its natural presence in the bones and teeth, has been considered as ideal biomaterial with excellent biocompatibility [2] and has been extensively used in many biomedical applications such as dental composites, [3] bone tissue engineering or bone graft substitution (scaffolds), [4][5][6][7] orthopedic implants, [8,9] coatings, [10] and antibacterial agents. [11] Recently, more efforts have been made to explore the potential of using CAP nanoparticles as vehicles for drug and gene delivery for their great affinity to DNA and various drugs and good release property.…”

Section: Introductionmentioning

confidence: 99%

Untitled

Vengala¹

2017

AJP

View full text Add to dashboard Cite

Introduction: To enhance the delivery of poorly-soluble drugs, we have explored aquasomes (three-layered, ceramic core based, and oligosaccharide-coated nanoparticles) as potential carriers for the delivery of model hydrophobic drug lornoxicam (log P = 3.15). Materials and Methods: Ceramic nanoparticles were prepared using coprecipitation by sonication method. Cellobiose was used for coating onto ceramic core followed by loading of the lornoxicam by partial adsorption mechanism. The prepared system was characterized for size, shape, drug loading efficiency, and in vitro release profile (both 0.1 N hydrochloric acid solution and phosphate buffer solution, pH 6.8). Colorimetric analysis of sugar coating was done using phenol sulfuric acid method. Results and Discussion: The formed particles were spherical with an average particle size in the range of 60-300 nm, with a media of 87 nm. The in vitro dissolution performance was compared with that of pure drug and better results were observed. The cumulative lornoxicam release for the aquasome formulation (49%) was found to be higher than that of pure drug (34%) and was found to be gradual and linear in acidic media. Whereas, in phosphate buffer solution, pH 6.8, an incomplete release was observed with the pure drug (51% in 2 h) and 95% release was observed within 90 min from the formulation. Conclusion: Ceramic nanoparticles can be used for the enhancement of dissolution profile of poorly soluble drugs.

show abstract

A 5–7 year in vivo study of high-strength hydroxyapatite/poly(l-lactide) composite rods for the internal fixation of bone fractures

Cited by 112 publications

References 23 publications

Biocomposites and hybrid biomaterials based on calcium orthophosphates

Biocomposites and hybrid biomaterials based on calcium orthophosphates

Balancing the Rates of New Bone Formation and Polymer Degradation Enhances Healing of Weight-Bearing Allograft/Polyurethane Composites in Rabbit Femoral Defects

Untitled

Contact Info

Product

Resources

About