Bone tissue regeneration and blood vessel formation are inseparable. How to realize the vascularization of bone repair scaffolds is an urgent problem in bone tissue engineering. The growth and development, mineralization maturity, reconstruction and remodeling, and tissue regeneration of bone are all based on forming an excellent vascularization network. In recent years, more and more researchers have used hydrogels to carry different cells, cytokines, metal ions and small molecules for in vitro vascularization and application in bone regeneration. Based on this background, this article reviews the hydrogel-based vascularization strategies in bone tissue engineering.
Objective To investigate the feasibility of differentiation of the marrow mesenchymal stem cells (MSCs) into the cells of the skin appendages andthe mechanism of their involvement in the wound healing. Methods The bone marrow was collected from Wistar rats by the flushing of the femurs, MSCs were isolated and purified by the density gradient centrifugation. Then, the MSCs were amplified and labelled with 5-bromo-2′-deoxyuridine (BrdU). The full-thickness skin wounds with an area of 1 cm×1 cm were made on the midback of the homogeneous male Wistar rats. At the same time, 1×106/ml BrdU-labelled MSCs were infused from thepenile vein. The specimens were harvested from the wound tissues on the 3rd dayand the 7th day after operation and were immunohistochemically stained by either BrdU or BrdU and pan-keratin. Results The BrdU positive cells appeared in thehypodermia, the sebaceous glands, and the hair follicles of the wounds, as wellas the medullary canal of the femurs. The double-staining showed the BrdU positive cells in the sebaceous glands and the hair follicles of the wounds expressedpan-keratin simultaneously. Conclusion During the course of the wound healing, MSCs are involved in the wound repair and can differentiate into the cells ofthe skin appendages under the microenvironment of the wound.
OBJECTIVE To emphasize the importance of reconstruction and repair after resection of soft tissue sarcoma. METHODS From November 1990 to November 1996, in 107 cases of soft tissue sarcoma 32 cases had received various reconstructive or reparative operations. Among the 32 cases, 4 cases were primary sarcomas and 28 cases were recurrent sarcomas. In surgical grading, 3 cases were of I B, 3 cases of II A and 26 cases of II B. Radical resection was performed in 13 cases, widen local resection in 17 cases and local excision in 2 cases. After operation, 13 cases received chemotherapy and 7 cases received radiotherapy. Reconstruction of blood vessels was performed in 3 cases, reconstruction of kinetic function in 16 cases, and repair of defect was carried out in 23 cases. RESULTS Thirty patients were followed up for 4 months to 6 years and 6 months. The clinical results showed that the local control rate of sarcoma was 80%, limb-salvage rate after reconstruction of blood vessels was 100%, the excellent and good rate after reconstruction of kinetic function was 87.5%, and the survival rate of the tissue flap of transplantation and transposition was 96%. CONCLUSION It was concluded that the reconstruction and repair after resection of soft tissue sarcoma was the extension of operative treatment, and was very important in lowering the recurrence rate and improving the life quality of the sufferings.
OBJECTIVE To investigate the effect of the emergent repair of peripheral nerve injury of the wrist. METHODS From July 1993 to December 1997, 17 cases were admitted, which 21 injured peripheral nerves were repaired emergently. Among them, there were 11 cases of median nerve injury, 2 cases of ulnar nerve injury and 4 cases of median and ulnar nerve injury. All the nerves were ruptured completely except one which was partially ruptured. The emergent operation was taken and the injured nerves were repaired by microsurgical technique. RESULTS Followed up 6 to 18 months after operation, 95.25% injured nerves had good outcome. CONCLUSION Because of the specific structure of the wrist, nerve injury at this part need to be repaired emergently. It can enhance the regeneration of the injured nerve, preserve the function of the intrinsic muscle of hand, and decrease the local adhesion.
Objective To investigate the application of transverse fascia in inguinal hernia repair. Methods In this study, 617 patients underwent inguinal hernia repair between January 1990 and December 2005 in our hospital were included, which were divided into two groups according to different operative ways: transverse fascia method group (n=337) and Bassini method group (n=280). Then intraoperative results, postoperative complications, and rehabilitated results of patients in two groups were compared. Results Compared with Bassini method group, the patients in transverse fascia method group did not show significant difference in operative time and blood loss during operation (Pgt;0.05). The differences of severe postoperative pain, testicular swelling, the time of the body’s restore for normal activities, and recurrence rate of patients between two groups were significant (Plt;0.05), while the difference of hematoma of scrotum and infection of incisional wound (Pgt;0.05). Conclusion The strengthening of posterior wall by transverse fascia and reconstruction of inner ring is a simple and effective method for inguinal hernia repair.
Objective To review the advances in repair of spinal cord injury by transplantation of marrow mesenchymal stem cells(MSCs). Methods The related articles in recent years were extensively reviewed,the biological characteristic of MSCs,the experimental and clinical studies on repair of spinal cord injury by transplantation of MSCs,the machanisms of immigration and therapy and the problems were discussed and analysed. Results The experimental and clinical studies demonstrated that the great advances was made in repair of spinal cord injury by transplantation of MSCs. After transplantation, MSCs could immigrate to the position of spinal cord injury, and differentiate into nervelike cells and secrete neurotrophic factors.So it could promote repair of injuryed spinal cord and recovery of neurologicalfunction. Conclusion Transplantation of MSCs was one of effective ways in repair of spinal cord injury, but many problems remain to be resolved.
Objective To review the research progress on the application of three-dimensional (3D) bioprinting technology in auricle repair and reconstruction. Methods The recent domestic and international research literature on 3D printing and auricle repair and reconstruction was extensively reviewed, and the concept of 3D bioprinting technology and research progress in auricle repair and reconstruction were summarized. Results The auricle possesses intricate anatomical structure and functionality, necessitating precise tissue reconstruction and morphological replication. Hence, 3D printing technology holds immense potential in auricle reconstruction. In contrast to conventional 3D printing technology, 3D bioprinting technology not only enables the simulation of auricular outer shape but also facilitates the precise distribution of cells within the scaffold during fabrication by incorporating cells into bioink. This approach mimics the composition and structure of natural tissues, thereby favoring the construction of biologically active auricular tissues and enhancing tissue repair outcomes. Conclusion 3D bioprinting technology enables the reconstruction of auricular tissues, avoiding potential complications associated with traditional autologous cartilage grafting. The primary challenge in current research lies in identifying bioinks that meet both the mechanical requirements of complex tissues and biological criteria.
Minimally invasive cardiac surgeries are the trend in the future. Among them, robotic cardiac surgery is the latest iteration with several key-hole incision, 3-dimentional visualization, and articulated instrumentation of 7 degree of ergonomic freedom for those complex procedures in the heart. In particular, robotic mitral valve surgery, as well as coronary artery bypass grafting, has evolved over the last decade and become the preferred method at certain specialized centers worldwide because of excellent results. Other cardiac procedures are in various stages of evolution. Stepwise innovation of robotic technology will continue to make robotic operations simpler, more efficient, and less invasive, which will encourage more surgeons to take up this technology and extend the benefits of robotic surgery to a larger patient population.
In order to preserve the major vessels of the extremities in the repair and reconstruction of wounds of the extremities, the distally based fascial pedicled island flap was applied clinically. Its axis and rotatary point were designed along orientation of the major arteries, and the blood supply was from the abundant vascular networks in the deep fascia. Twenty-two cases with exposure of tendon and bone including 10 upper limbs and 12 lower limbs were treated. The flap area of forearm ranged from 7 cm x 8 cm to 12 cm x 9 cm and the ratio of the length to width of the pedicle was 1: 1-2. The flap area of the calf ranged from 10 cm x 6 cm to 16.5 cm x 12 cm and the ratio of the length to width of the pedicle was 2:1. The rotatary angle was 130 degrees-170 degrees. After operation, 18 flaps were survived completely, 2 cases had partial necrosis on the margin, 2 failures received cross-leg flap in the second operation. The patients were followed up with an average of 13.5 months (ranged from 3 months to 2 years). The conclusions were as follows: 1. the blood supply of this type of flap was reliable and the major arteries of the extremities needed not to be sacrificed; 2. the preparation of the flap was easy and the survival rate was satisfactory; 3. the shortcomings of this flap were unsightly incision scar and the limited size of flap and; 4. during the operation, the compression of the pedicle must be avoided.
Objective To evaluate the effectiveness of ISOBAR TTL dynamic stabilization with pars bone grafting for the treatment of lumbar spondylolysis. Methods A retrospective analysis was made the clinical data of 26 patients with lumbar spondylolysis who received ISOBAR TTL dynamic stabilization with pars bone grafting between September 2009 and March 2014. There were 14 males and 12 females, with a mean age of 31 years (range, 19-47 years). The disease duration ranged from 9 to 60 months (mean, 16 months). Preoperative lumbar anteroposterior and lateral X-ray films, CT three-dimensional reconstruction, and MRI scans were performed to identify the location of pars defect. The involved levels were L4 in 9 cases and L5 in 17 cases. There were 10 cases of pure spondylolysis and 16 cases of spondylolysis accompanied with I degree slipping. The clinical outcome was assessed by visual analogue scale (VAS) and Oswestry disability index (ODI) scores at preoperation and 1 week, 3 months, 6 months after operation, and at last follow-up. The lumbar CT three-dimensional reconstruction was obtained at 6 months after operation to evaluate bone fusion of the pars. The adjacent segment degeneration was assessed by the University of California at Los Angeles (UCLA) grading scale at preoperation and last follow-up. Results All incisions healed by first intention; no infection, cerebrospinal fluid leakage, or pain at iliac crest donor site occurred. Twenty-six patients were followed up 2-5 years (mean, 36.5 months). No secondary spondylolisthesis, internal fixation loosening and breakage were found during follow-up. The postoperative VAS and ODI scores showed significant differences (P<0.05) when compared with preoperative scores, and the scores at 3 months, 6 months, and last follow-up were significantly better than that at 1 week (P<0.05), but no significant difference was shown between the other time points after operation (P>0.05). The CT three-dimensional reconstruction indicated satisfactory union at the pars in 23 cases (88.5%) at 6 months after operation. Of the 3 nonunion patients, good union was obtained in 1 patient at 1 year after operation; nonunion was observed in 2 patients at last follow-up, but low back pain was obviously alleviated. According to the UCLA grading scale, 20 cases were rated as grade I and 6 cases as grade II at last follow-up, which was the same as preoperative grade and indicated no adjacent segment degeneration. Conclusion It is safe and effective to use the ISOBAR TTL dynamic stabilization with pars bone grafting technique to treat lumbar spondylolysis with or without degree I slipping. The fusion rate is satisfactory, and adjacent segment degeneration can be slowed down after lumbar fusion surgery.