Novel resin tissue array system reduces sample preparation time, labour and reagent costs in bone tissue histology.

Resin histology plays an essential role in the analysis of hard tissues, such as bone and teeth, as well as in the context of metallic implant analysis. However, the techniques of resin embedding, followed by ground sectioning, are very costly due to significantly increased reagent cost and labour time when compared to the conventional paraffin histology approach. In the present study, a novel resin array system was developed to increase the affordability of a project analysing rat femur tissues containing metallic or polymeric implants. The resin array system enabled the simultaneous embedding of the femur samples in groups of eight samples compared to the conventional resin method where samples are processed individually. The ground sections produced with the resin array system allowed uniform ROI selection, ground section thickness, staining consistency, and histological analysis with Goldner's trichrome stain, offering a substantial opportunity for reproducible immunohistochemistry which is unable to be achieved when processing samples embedded individually. The application of this novel resin array system significantly reduced resource usage when compared to doing the same analysis on individual samples. A reduction of approximately 40% was achieved for both total labour time and total reagent cost through the use of the array system compared with individual embedding. This novel resin array system has widespread applicability to many bone, hard tissue, and metallic implant studies, offering substantial conservation of research funds and increased accessibility to advanced techniques for commercial partners due to more cost-effective sample preparation and more accurate, reproducible data.

A preclinical large-animal model for the assessment of critical-size load-bearing bone defect reconstruction.

Critical-size bone defects, which require large-volume tissue reconstruction, remain a clinical challenge. Bone engineering has the potential to provide new treatment concepts, yet clinical translation requires anatomically and physiologically relevant preclinical models. The ovine critical-size long-bone defect model has been validated in numerous studies as a preclinical tool for evaluating both conventional and novel bone-engineering concepts. With sufficient training and experience in large-animal studies, it is a technically feasible procedure with a high level of reproducibility when appropriate preoperative and postoperative management protocols are followed. The model can be established by following a procedure that includes the following stages: (i) preoperative planning and preparation, (ii) the surgical approach, (iii) postoperative management, and (iv) postmortem analysis. Using this model, full results for peer-reviewed publication can be attained within 2 years. In this protocol, we comprehensively describe how to establish proficiency using the preclinical model for the evaluation of a range of bone defect reconstruction options.

A histomorphometric assessment of collagen-stabilized anorganic bovine bone mineral in maxillary sinus augmentation - a randomized controlled trial in sheep.

OBJECTIVE: To histomorphometrically compare the use of collagen-stabilized anorganic bovine bone (ABBM-C) (test) to anorganic bovine bone + autogenous bone (ABBM + AB) (control) in maxillary sinus augmentation. MATERIALS AND METHODS: Nine sheep underwent bilateral sinus augmentation. Each sinus was randomized to receive either control or test bone graft. Three animals were sacrificed at 8 weeks, and six animals were sacrificed at 16 weeks post-grafting. The 18 sinuses were processed for histomorphometry, which assessed the area fraction of new bone (%NB), residual graft (%RG) and soft tissue components (% STM), as well as graft particle osseointegration (% OI), within three zones equally distributed from the augmented sinus floor. RESULTS: At week 16, a significant increase in %NB was evident across all three zones in the control group when compared to week 8. A significantly greater %NB was evident in the control group when compared to the test group in zones 2 (P < 0.001) and 3 (P < 0.001). There was a significant increase in %OI in week 16 when compared to week 8 across all three zones in the control group (P < 0.001). %OI in the control group was significantly greater across all three zones when compared to the test group at week 16 (P < 0.001). Zone was found to be a significant main effect (P < 0.001) that was independent of time and treatment with decreasing %OI in distant zones. %RG did not significantly change with time for both groups. There was a significant reduction in %ST in week 16 when compared to week 8 across all three zones in the control group (P < 0.001). %ST in the test group was significantly greater across all zones when compared to the control group at week 16 (P < 0.001). CONCLUSION: Both groups exhibited very similar histomorphometric measurements in the zones proximal to the resident sinus wall. The % NB and % OI were greatest in the zones proximal to resident bony walls and gradually decreased as the distance from the proximal walls increased. There was greater % NB and % OI in the control group when compared to the test group in the distant zone.