Prefabrication of Vascularized Bone Flap by Demineralized Bone Matrix

Bone Graft Prefabrication Following the In Vivo Bioreactor Principle

Large bone defect treatment represents a great challenge due to the difficulty of functional and esthetic reconstruction. Tissue-engineered bone grafts created by in vitro manipulation of bioscaffolds, seed cells, and growth factors have been considered potential treatments for bone defect reconstruction. However, a significant gap remains between experimental successes and clinical translation. An emerging strategy for bridging this gap is using the in vivo bioreactor principle and flap prefabrication techniques. This principle focuses on using the body as a bioreactor to cultivate the traditional triad (bioscaffolds, seed cells, and growth factors) and leveraging the body's self-regenerative capacity to regenerate new tissue. Additionally, flap prefabrication techniques allow the regenerated bone grafts to be transferred as prefabricated bone flaps for bone defect reconstruction. Such a strategy has been used successfully for reconstructing critical-sized bone defects in animal models and humans. Here, we highlight this concept and provide some perspective on how to translate current knowledge into clinical practice.

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The in vivo bioreactor principle and flap prefabrication technique is a promising strategy for bone defect reconstruction.

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The in vivo bioreactor principle focuses on using the body’s self-regenerative capacity to regenerate new tissue.

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This strategy has been successfully used to reconstruct critical-sized bone defects in humans.

Bone grafting, orthopaedic biomaterials, and the clinical need for bone engineering

As the population ages, the number of operations performed on bone is expected to increase. Diseases such as arthritis, tumours, and trauma can lead to defects in the skeleton requiring an operation to replace or restore the lost bone. Surgeons can use autografts, allografts, and/or bone graft substitutes to restore areas of bone loss. Surgical implants are also used in addition or in isolation to replace the diseased bone. This review considers the application of available bone grafts in different clinical settings. It also discusses recently introduced bioactive biomaterials and highlights the clinical difficulties and technological deficiencies that exist in our current surgical practice.

A comparison of bone reconstruction following application of bone matrix gelatin and autogenous bone grafts to alveolar defects: an animal study

The aim of this study was to compare the quantity and quality of osseous healing of bone matrix gelatin (BMG) with autogenous bone graft (ABG) in cat models. Osseous defects (5 x 5mm) were made through upper alveolar bone distal to the canines in the left and right quadrants (maxilla) in each of twelve Persian male cats and filled randomly with BMG and ABG. The repair response was examined on days 14, 28, and 56 after surgery (n=4 per bone substitute per time point). Qualitative histological and quantitative histometric analysis including percentage of new formed bone fill (BF) and density were done. The inter-treatment comparison of mean levels of BF at specific time points showed consistently greater levels within BMG treated defects and reached significance on days 14, 28, and 56 (P<0.05). Regarding bone density (BD), there was no significant difference between BMG and ABG on days 14 and 28 (P>0.05). On day 56, BD was significantly higher within BMG group (P<0.05). Intra-treatment evaluation of bone formation in each group showed that BD significantly increased during treatment (P<0.05), and BF in BMG group reached significance at every time point but in ABG group only increase from day 28 to 56 reached significance (P<0. 05). Our results support the use of BMG to treat bone defects. Clinicians might expect better clinical outcomes without the possibility of side effects and morbidity associated with the harvest of autogenous bone.