To serve as carriers of cells and bioactive molecules, three-dimensional scaffolds play a key role in bone defect repair. The chemical component and microstructure of the scaffold can affect the mechanical properties and seed cells. A variety of fabrication techniques have been used in producing scaffolds, some made random porous structure, some created well-designed structure using rapid prototyping methods, and others prepared bio-derived materials as scaffolds. However, scaffolds may vary in their inner structure, mechanical properties and repairing efficiency as well because of different manufacturing methods. In this review, we overview the main achievements concerning the effects of material and microstructure on the mechanical performance, seed cells and defect repair of bone scaffolds.
Objective To review the research progress on acid fibroblast growth factor (aFGF) in promoting tissue injury repair and its mechanism of action. Methods By searching and reviewing the basic and clinical studies on aFGF published in recent years, the roles of aFGF in tissue injury including full-thickness skin, mucous and skin barrier, bone and nerve fiber were summarized. Results As a key member of the FGF family, aFGF exhibits potent mitogenic activity, it can regulate various cells proliferation and migration, accelerate extracellular matrix synthesis, promote angiogenesis and nerve fiber repair, upregulate tight junction protein expression, and therefore exert dual regulatory effects on dermal and epidermal regeneration and repair. It demonstrates promising clinical application for full-thickness healing and skin and mucosal barriers repair. Additionally, it mediates the regeneration and differentiation of osteoblasts, cardiomyocytes, and follicle cells, exhibiting potential for repairing multiple tissues and organs. Furthermore, the aFGF's functions in regulating energy metabolism, immune-inflammatory responses, and alleviating aging have revealed in recent years, indicating a broad clinical application. Conclusion aFGF is a valuable member of the FGF family. It is widely used in various kinds of wound healing, besides, it also holds promising application in multiple tissue and organ regeneration and repair.
Mechano growth factor (MGF) is an autocrine/paracrine factor and sensitive to mechanical stimulation. MGF can be highly expressed in various soft tissues under physical stimuli, biochemistry stimuli or in damaged situation. MGF may "compensate" the stress for tissue in the processing of tissue repair. MGF can effectively accelerate the repair of the soft tissue by promoting the proliferation, migration and differentiation of cells. This paper summarizes the MGF expressions in different soft tissues and their functions in soft tissue repair. The paper also discusses current problems and challenges in using MGF to repair the soft tissue.
Mesenchymal stem cells (MSCs) are pluripotent stem cells with high self-proliferation and multidirectional differentiation potential. They also have other functions including immune regulation, paracrine and so on, playing an important role in repairing injured tissues. In recent years, a lot of research has been done on how MSCs promote skin injury repair, and a lot of progress has been made. Compared with direct injection of MSCs in the wound area, some special treatments or transplantation methods could enhance the ability of MSCs to repair skin injury. This paper mainly discusses the role of MSCs in skin injury repair and technical ways to improve its repairing capacity, and discusses the existing problems in this field and prospects for future research directions.
ObjectiveTo explore the biological mechanisms of tibial transverse transport (TTT) for promoting microcirculation and tissue repair.MethodsThe clinical application and animal model study of TTT were reviewed.ResultsThe possible biological mechanisms of TTT for promoting microvascular network formation and tissue repair: ① Tibial corticotomy reduces intramedullary pressure and improves microcirculation; ② Tension stress stimulation promotes microvascular regeneration and accelerates the formation of new “transcortical vessels” network; ③ Systemic mobilization of stem cells, mediating local inflammation, etc.ConclusionTTT has been clinically proven to be effective for the management of lower limb ischemia and diabetic foot ulcers. The surgical procedure is relatively easy with little adverse effects on bone structures. The TTT has good application prospects despite the biological mechanisms of which still need further exploration.
ObjectiveTo review the application of cell derived decellularized extracellular matrix (CDM) in tissue engineering. Methods The literature related to the application of CDM in tissue engineering was extensively reviewed and analyzed. Results CDM is a mixture of cells and their secretory products obtained by culturing cells in vitro for a period of time, and then the mixture is treated by decellularization. Compared with tissue derived decellularized extracellular matrix (TDM), CDM can screen and utilize pathogen-free autologous cells, effectively avoiding the possible shortcomings of TDM, such as immune response and limited sources. In addition, by selecting the cell source, controlling the culture conditions, and selecting the template scaffold, the composition, structure, and mechanical properties of the scaffold can be controlled to obtain the desired scaffold. CDM retains the components and microstructure of extracellular matrix and has excellent biological functions, so it has become the focus of tissue engineering scaffolds. ConclusionCDM is superior in the field of tissue engineering because of its outstanding adjustability, safety, and high bioactivity. With the continuous progress of technology, CDM stents suitable for clinical use are expected to continue to emerge.
Objective To review the recent advances in the application of exosome-hydrogel system for wound healing. Methods A wide range of recent domestic and international studies were reviewed to systematically outline the roles and mechanisms of exosomes, hydrogels, and their composite system in promoting wound repair. Results Wound healing is a complex and finely regulated process. Traditional therapies lack targeted regulation of key mechanisms such as inflammation control, angiogenesis, collagen remodeling, and re-epithelialization. The exosome-hydrogel system enhances wound repair through targeted modulation of these mechanisms and provides effective protection against bacterial infection, hypoxia, excessive oxidative stress, and hyperglycemic microenvironments. Conclusion The exosome-hydrogel system represents an emerging approach for chronic wound repair and skin regeneration, potentially overcoming the inherent limitations of traditional therapies. Nevertheless, the lack of standardized preparation methods and dosing protocols calls for further optimization.
ObjectiveTo investigate the effectiveness of medial sural artery perforator free flap (MSAP) for repairing defect after tongue cancer ablation.
MethodsBetween March 2013 and April 2014, the defects after tongue carcinoma resection were repaired with MSAP in 12 patients, including 8 cases of high or medium differentiated squamous cell carcinoma (SCC) and 4 cases of moderately-poor differentiated SCC. There were 7 males and 5 females with a median age of 55 years (range, 45-68 years). The disease duration ranged from 2.0 to 8.5 months (mean, 4.3 months). The tumor located at the tongue edge in 8 cases and at the tongue abdomen in 4 cases (mouth floor infiltration in 1 case). According to TNM stage, 7 cases were rated as T2N0M0, 2 cases as T2N1M0, 2 cases as T3N1M0, and 1 case as T4N1M0. The size of tumor ranged from 3.0 cm×2.0 cm to 4.5 cm×3.0 cm. The size of MSAP varied from 4.0 cm×3.5 cm to 6.5 cm×6.0 cm.
ResultsThe time of total operation ranged from 5.5 to 8.3 hours (mean, 6.8 hours), and flap harvesting time ranged from 54 to 85 minutes (mean, 65.6 minutes). The other flaps survived except 1 case of vein crisis. All the patients were followed up 6-18 months (mean, 13.7 months). With time passing, the pronunciation got better, and the skin showed mucosa-like change; the patients were capable of normal language exchange at 6 months after operation. No obvious scar on the leg or limitation of limb motion was observed.
ConclusionThe MSAP is reliable for repair of defect after tongue cancer ablation, with the advantages of satisfactory recovery of tongue appearance, language function, and less donor site morbidity.
Objective
To explore the operative methods and the short-term effectiveness to repair chronic tears of the 2nd plantar plate.
Methods
Between June 2012 and June 2013, 14 patients with chronic tears of the 2nd plantar plate were treated. There were 4 males and 10 females with an average age of 65.9 years (range, 51-82 years) and with an average disease duration of 6.2 years (range, 5-9 years). The left side was involved in 5 cases and the right side in 9 cases. One patient had simple hammer toe; 2 patients had hallux valgus and claw toe; and 11 patients had hallux valgus and hammer toes. All of them had unstable the 2nd metatarsophalangeal joints. The results of modified Lachman test and drawer test were positive. The surgical treatment included a Weil osteotomy and plantar plate repair operation for rupture via dorsal incision after correcting hallux valgus.
Results
Primary healing of incision was obtained in all patients. Twelve patients were followed up 6-12 months (mean, 8.2 months). Hallux valgus, claw toe, and hammer toe were all corrected. The results of modified Lachman test and drawer test were negative at 3 months after operation. Mild pain of the 2nd metatarsophalangeal joint occurred, but no stiff was observed in 2 cases at 6 months after operation. The midfoot and forefoot score of American Orthopedic Foot and Ankle Society (AOFAS) was 90.50 ± 3.73 at last follow-up, which was significantly higher (t=21.724, P=0.000) than preoperative score (57.33 ± 4.99).
Conclusion
The plantar plate is the key to maintain the stability of the metatarsophalangeal joints, and surgical repair can achieve good short-term effectiveness in treating chronic tears of the 2nd plantar plate.
ObjectiveTo separate peripheral blood mesenchymal stem cells (PBMSC) and peripheral blood endothelial progenitor cells (PBEPC) from peripheral blood, and investigate the biological characteristics of composite cell sheets of PBMSC and PBEPC.MethodsThe peripheral blood of healthy adult New Zealand white rabbits was extracted and PBMSC and PBEPC were separated by density gradient centrifugation. Morphological observation and identification of PBMSC and PBEPC were performed. The 3rd generation of PBMSC and PBEPC were used to construct a composite cell sheet at a ratio of 1∶1, and the 3rd generation of PBMSC was used to construct a single cell sheet as control. The distributions of cells in two kinds of cell sheets were observed by HE staining. In addition, the expression of alkaline phosphatase (ALP), osteocalcin (OCN), and vascular endothelial growth factor (VEGF) in the supernatants of cell sheets were observed by ELISA at 1, 5, and 10 days after osteogenic induction.ResultsThe morphology of PBMSC was spindle-shaped or polygonal, and PBMSC had good abilities of osteogenic and adipogenic differentiation. The morphology of PBEPC was paved stone-like, and the tube-forming test of PBEPC was positive. Two kinds of cell sheets were white translucent. The results of HE staining showed that the composite cell sheet had more cell layers and higher cell density than the single cell sheet. The expressions of ALP, OCN, and VEGF in the supernatant of the two groups of cell sheets increased with the time of induction. The expression of OCN in the group of composite cell sheet was significantly higher than that in the group of single cell sheet on the 5th and 10th day, ALP on the 10th day was significantly higher than that in the group of single cell sheet, VEGF expression on the 1st, 5th, and 10th day was significantly higher than that in the group of single cell sheet, all showing significant differences (P<0.05), and there was no significant difference between the two groups at other time points (P>0.05).ConclusionPBMSC have stable differentiation ability, and they have good application prospects because of their minimally invasive access. Composite cell membranes constructed by co-culture of two kinds of cells and induction of membrane formation provides a new idea and exploration for tissue defect repair.
