Decellularized xenogenic bone graft for repair of segmental bone defect in rabbits.

Background: Bone grafting is a preferred treatment option for the healing of large diaphyseal bone defects and is useful in the management of nonunion, delayed union, and tumor resection. Aims: To investigate a decellularization protocol of bovine cancellous bone for xenogenic implantation in radial bone defects in rabbits. Methods: Bovine bone scaffolds fabricated with various decellularization protocols viz phosphate buffer saline (PBS), 1% sodium dodecyl sulfate (SDS), and rapid freeze and thaw technique. The manufactured scaffolds were characterized by biomechanical testing, histological staining, and scanning electron microscopy. A 10 mm rabbit radius bone defect was repaired with autograft and SDS treated and rapid freeze and thaw in groups A, B, and C respectively. Healing was evaluated by radiography and histopathology at 0, 30, 60, and 90 days. The grafts were also checked for host tissue reaction and incorporation into the defect. Results: The freeze and thaw group showed complete elimination of all cellular nuclei, regular arrangement of collagen fiber, and no significant difference in tensile strength compared to 1% SDS treated and native groups. The in vivo radiographic and histopathological study showed that the rapid freeze and thaw group had complete bridging of the bone gap defect with new bone formation and they were immunologically less reactive compared to group B. Conclusion: The in vitro and in vivo evaluation of the grafts suggested that freeze and thaw technique was most superior to all other techniques for effective decellularization and augmentation of bone healing with better integration of the graft into the host.

Polypropylene mesh seeded with fibroblasts: A new approach for the repair of abdominal wall defects in rats.

PURPOSE: The purpose of study was to develop bioengineered scaffolds by seeding primary mouse embryo fibroblast cells (p-MEF) on polypropylene mesh and to test its efficacy for the repair of abdominal wall defects in rats. METHODS: The study was conducted on 18 clinically healthy adult Wistar rats of either sex. The animals were randomly divided into two equal groups having nine animals in each group. In both the groups a 20mm×20mm size full thickness muscle defect was created under xylazine and ketamine anesthesia in the mid-ventral abdominal wall. In group I the defect was repaired with polypropylene mesh alone and in group II it was repaired with p-MEF seeded polypropylene mesh. Matrices were implanted by synthetic absorbable suture material (polyglycolic acid) in continuous suture pattern. The efficacy of the bio-engineered matrices in the reconstruction of full thickness abdominal wall defects was evaluated on the basis of macro and histopathological observations. RESULTS: Macroscopic observations revealed that adhesions with skin and abdominal viscera were minimum in group II as compared to group I. Histopathological observations confirmed better fibroplasia and collagen fiber arrangement in group II. No recurrence of hernia was found in both the groups. CONCLUSION: Hernias are effectively repaired by implanting polypropylene mesh. However, this work demonstrates that in vitro seeding of mesh with fibroblasts resulted in earlier subsidization of pain, angiogenesis and deposition of collagen, increased thickness of matrices with lesser adhesions with underlying viscera. On the basis of the results p-MEF seeded mesh was better than non-seeded mesh for repair of abdominal wall defects in rats.

Bioengineered acellular dermal matrices for the repair of abdominal wall defects in rats.

PURPOSE: Acellular grafts can be used as a better substitute for the prosthetic meshes in reconstruction of abdominal wall defect. The purpose of study was to develop bioengineered scaffolds by seeding primary mouse embryo fibroblast cells (p-MEF) on decellularized rabbit skin and to test the efficacy of these scaffolds for the repair of abdominal wall defects in rats. METHODS: The study was conducted on 18 clinically healthy adult Wistar rats of either sex. The animals were randomly divided into two equal groups having nine animals in each group. In both the groups a 20 × 20 mm(2) size full thickness muscle defect was created under xylazine and ketamine anaesthesia in the mid-ventral abdominal wall. In group I the defect was repaired with acellular dermal matrix alone and in group II it was repaired with p-MEF seeded dermal matrix. Matrices were implanted by synthetic absorbable suture material (polyglycolic acid) in continuous suture pattern. The efficacy of the bioengineered matrices in the reconstruction of full thickness abdominal wall defects was evaluated. RESULTS: Macroscopic observations revealed that adhesions with skin and abdominal viscera were found to be less in group II as compared to group I. Immunological reactions were reduced in group II. Histopathological observations also revealed that fibroplasia and collagen fiber arrangement was found to be better in group II. No recurrence of hernia was found in both the groups. CONCLUSION: On the basis of the results bioengineered cell seeded scaffolds were found to be better than non-cell seeded scaffolds for the repair of abdominal wall defects in rats.